Initial version of stressapptest

From http://stressapptest.googlecode.com/files/stressapptest-1.0.4_autoconf.tar.gz
with the addition of MODULE_LICENSE_APACHE2 and NOTICE.

Change-Id: I1f3e80fce2c500766bcc7a67d7d42e485ddf57b4

27 files changed, 11548 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
new file mode 100644
index 0000000..e044974
--- /dev/null
+++ b/src/Makefile.am
@@ -0,0 +1,31 @@
+bin_PROGRAMS = stressapptest
+
+AM_DEFAULT_SOURCE_EXT=.cc
+
+MAINFILES = main.cc
+CFILES = os.cc
+CFILES += os_factory.cc
+CFILES += pattern.cc
+CFILES += queue.cc
+CFILES += sat.cc
+CFILES += sat_factory.cc
+CFILES += worker.cc
+CFILES += finelock_queue.cc
+CFILES += error_diag.cc
+CFILES += disk_blocks.cc
+CFILES += adler32memcpy.cc
+CFILES += logger.cc
+
+HFILES = os.h
+HFILES += pattern.h
+HFILES += queue.h
+HFILES += sat.h
+HFILES += worker.h
+HFILES += sattypes.h
+HFILES += finelock_queue.h
+HFILES += error_diag.h
+HFILES += disk_blocks.h
+HFILES += adler32memcpy.h
+HFILES += logger.h
+
+stressapptest_SOURCES = $(MAINFILES) $(CFILES) $(HFILES)
diff --git a/src/Makefile.in b/src/Makefile.in
new file mode 100644
index 0000000..f62d1ac
--- /dev/null
+++ b/src/Makefile.in
@@ -0,0 +1,519 @@
+# Makefile.in generated by automake 1.11.1 from Makefile.am.
+# @configure_input@
+
+# Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
+# 2003, 2004, 2005, 2006, 2007, 2008, 2009  Free Software Foundation,
+# Inc.
+# This Makefile.in is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
+# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE.
+
+@SET_MAKE@
+
+VPATH = @srcdir@
+pkgdatadir = $(datadir)/@PACKAGE@
+pkgincludedir = $(includedir)/@PACKAGE@
+pkglibdir = $(libdir)/@PACKAGE@
+pkglibexecdir = $(libexecdir)/@PACKAGE@
+am__cd = CDPATH="$${ZSH_VERSION+.}$(PATH_SEPARATOR)" && cd
+install_sh_DATA = $(install_sh) -c -m 644
+install_sh_PROGRAM = $(install_sh) -c
+install_sh_SCRIPT = $(install_sh) -c
+INSTALL_HEADER = $(INSTALL_DATA)
+transform = $(program_transform_name)
+NORMAL_INSTALL = :
+PRE_INSTALL = :
+POST_INSTALL = :
+NORMAL_UNINSTALL = :
+PRE_UNINSTALL = :
+POST_UNINSTALL = :
+build_triplet = @build@
+host_triplet = @host@
+target_triplet = @target@
+bin_PROGRAMS = stressapptest$(EXEEXT)
+subdir = src
+DIST_COMMON = $(srcdir)/Makefile.am $(srcdir)/Makefile.in \
+	$(srcdir)/stressapptest_config.h.in
+ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
+am__aclocal_m4_deps = $(top_srcdir)/configure.ac
+am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
+	$(ACLOCAL_M4)
+mkinstalldirs = $(install_sh) -d
+CONFIG_HEADER = stressapptest_config.h
+CONFIG_CLEAN_FILES =
+CONFIG_CLEAN_VPATH_FILES =
+am__installdirs = "$(DESTDIR)$(bindir)"
+PROGRAMS = $(bin_PROGRAMS)
+am__objects_1 = main.$(OBJEXT)
+am__objects_2 = os.$(OBJEXT) os_factory.$(OBJEXT) pattern.$(OBJEXT) \
+	queue.$(OBJEXT) sat.$(OBJEXT) sat_factory.$(OBJEXT) \
+	worker.$(OBJEXT) finelock_queue.$(OBJEXT) error_diag.$(OBJEXT) \
+	disk_blocks.$(OBJEXT) adler32memcpy.$(OBJEXT) logger.$(OBJEXT)
+am__objects_3 =
+am_stressapptest_OBJECTS = $(am__objects_1) $(am__objects_2) \
+	$(am__objects_3)
+stressapptest_OBJECTS = $(am_stressapptest_OBJECTS)
+stressapptest_LDADD = $(LDADD)
+DEFAULT_INCLUDES = -I.@am__isrc@
+depcomp = $(SHELL) $(top_srcdir)/depcomp
+am__depfiles_maybe = depfiles
+am__mv = mv -f
+CXXCOMPILE = $(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) \
+	$(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CXXFLAGS) $(CXXFLAGS)
+CXXLD = $(CXX)
+CXXLINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) $(AM_LDFLAGS) $(LDFLAGS) \
+	-o $@
+COMPILE = $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) \
+	$(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)
+CCLD = $(CC)
+LINK = $(CCLD) $(AM_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@
+SOURCES = $(stressapptest_SOURCES)
+DIST_SOURCES = $(stressapptest_SOURCES)
+ETAGS = etags
+CTAGS = ctags
+DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
+ACLOCAL = @ACLOCAL@
+AMTAR = @AMTAR@
+AUTOCONF = @AUTOCONF@
+AUTOHEADER = @AUTOHEADER@
+AUTOMAKE = @AUTOMAKE@
+AWK = @AWK@
+CC = @CC@
+CCDEPMODE = @CCDEPMODE@
+CFLAGS = @CFLAGS@
+CPP = @CPP@
+CPPFLAGS = @CPPFLAGS@
+CXX = @CXX@
+CXXDEPMODE = @CXXDEPMODE@
+CXXFLAGS = @CXXFLAGS@
+CYGPATH_W = @CYGPATH_W@
+DEFS = @DEFS@
+DEPDIR = @DEPDIR@
+ECHO_C = @ECHO_C@
+ECHO_N = @ECHO_N@
+ECHO_T = @ECHO_T@
+EGREP = @EGREP@
+EXEEXT = @EXEEXT@
+GREP = @GREP@
+INSTALL = @INSTALL@
+INSTALL_DATA = @INSTALL_DATA@
+INSTALL_PROGRAM = @INSTALL_PROGRAM@
+INSTALL_SCRIPT = @INSTALL_SCRIPT@
+INSTALL_STRIP_PROGRAM = @INSTALL_STRIP_PROGRAM@
+LDFLAGS = @LDFLAGS@
+LIBOBJS = @LIBOBJS@
+LIBS = @LIBS@
+LTLIBOBJS = @LTLIBOBJS@
+MAKEINFO = @MAKEINFO@
+MKDIR_P = @MKDIR_P@
+OBJEXT = @OBJEXT@
+PACKAGE = @PACKAGE@
+PACKAGE_BUGREPORT = @PACKAGE_BUGREPORT@
+PACKAGE_NAME = @PACKAGE_NAME@
+PACKAGE_STRING = @PACKAGE_STRING@
+PACKAGE_TARNAME = @PACKAGE_TARNAME@
+PACKAGE_URL = @PACKAGE_URL@
+PACKAGE_VERSION = @PACKAGE_VERSION@
+PATH_SEPARATOR = @PATH_SEPARATOR@
+SET_MAKE = @SET_MAKE@
+SHELL = @SHELL@
+STRIP = @STRIP@
+VERSION = @VERSION@
+abs_builddir = @abs_builddir@
+abs_srcdir = @abs_srcdir@
+abs_top_builddir = @abs_top_builddir@
+abs_top_srcdir = @abs_top_srcdir@
+ac_ct_CC = @ac_ct_CC@
+ac_ct_CXX = @ac_ct_CXX@
+am__include = @am__include@
+am__leading_dot = @am__leading_dot@
+am__quote = @am__quote@
+am__tar = @am__tar@
+am__untar = @am__untar@
+bindir = @bindir@
+build = @build@
+build_alias = @build_alias@
+build_cpu = @build_cpu@
+build_os = @build_os@
+build_vendor = @build_vendor@
+builddir = @builddir@
+datadir = @datadir@
+datarootdir = @datarootdir@
+docdir = @docdir@
+dvidir = @dvidir@
+exec_prefix = @exec_prefix@
+host = @host@
+host_alias = @host_alias@
+host_cpu = @host_cpu@
+host_os = @host_os@
+host_vendor = @host_vendor@
+htmldir = @htmldir@
+includedir = @includedir@
+infodir = @infodir@
+install_sh = @install_sh@
+libdir = @libdir@
+libexecdir = @libexecdir@
+localedir = @localedir@
+localstatedir = @localstatedir@
+mandir = @mandir@
+mkdir_p = @mkdir_p@
+oldincludedir = @oldincludedir@
+pdfdir = @pdfdir@
+prefix = @prefix@
+program_transform_name = @program_transform_name@
+psdir = @psdir@
+sbindir = @sbindir@
+sharedstatedir = @sharedstatedir@
+srcdir = @srcdir@
+sysconfdir = @sysconfdir@
+target = @target@
+target_alias = @target_alias@
+target_cpu = @target_cpu@
+target_os = @target_os@
+target_vendor = @target_vendor@
+top_build_prefix = @top_build_prefix@
+top_builddir = @top_builddir@
+top_srcdir = @top_srcdir@
+AM_DEFAULT_SOURCE_EXT = .cc
+MAINFILES = main.cc
+CFILES = os.cc os_factory.cc pattern.cc queue.cc sat.cc sat_factory.cc \
+	worker.cc finelock_queue.cc error_diag.cc disk_blocks.cc \
+	adler32memcpy.cc logger.cc
+HFILES = os.h pattern.h queue.h sat.h worker.h sattypes.h \
+	finelock_queue.h error_diag.h disk_blocks.h adler32memcpy.h \
+	logger.h
+stressapptest_SOURCES = $(MAINFILES) $(CFILES) $(HFILES)
+all: stressapptest_config.h
+	$(MAKE) $(AM_MAKEFLAGS) all-am
+
+.SUFFIXES:
+.SUFFIXES: .cc .o .obj
+$(srcdir)/Makefile.in:  $(srcdir)/Makefile.am  $(am__configure_deps)
+	@for dep in $?; do \
+	  case '$(am__configure_deps)' in \
+	    *$$dep*) \
+	      ( cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh ) \
+	        && { if test -f $@; then exit 0; else break; fi; }; \
+	      exit 1;; \
+	  esac; \
+	done; \
+	echo ' cd $(top_srcdir) && $(AUTOMAKE) --foreign src/Makefile'; \
+	$(am__cd) $(top_srcdir) && \
+	  $(AUTOMAKE) --foreign src/Makefile
+.PRECIOUS: Makefile
+Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status
+	@case '$?' in \
+	  *config.status*) \
+	    cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh;; \
+	  *) \
+	    echo ' cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe)'; \
+	    cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe);; \
+	esac;
+
+$(top_builddir)/config.status: $(top_srcdir)/configure $(CONFIG_STATUS_DEPENDENCIES)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+
+$(top_srcdir)/configure:  $(am__configure_deps)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+$(ACLOCAL_M4):  $(am__aclocal_m4_deps)
+	cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
+$(am__aclocal_m4_deps):
+
+stressapptest_config.h: stamp-h1
+	@if test ! -f $@; then \
+	  rm -f stamp-h1; \
+	  $(MAKE) $(AM_MAKEFLAGS) stamp-h1; \
+	else :; fi
+
+stamp-h1: $(srcdir)/stressapptest_config.h.in $(top_builddir)/config.status
+	@rm -f stamp-h1
+	cd $(top_builddir) && $(SHELL) ./config.status src/stressapptest_config.h
+$(srcdir)/stressapptest_config.h.in:  $(am__configure_deps) 
+	($(am__cd) $(top_srcdir) && $(AUTOHEADER))
+	rm -f stamp-h1
+	touch $@
+
+distclean-hdr:
+	-rm -f stressapptest_config.h stamp-h1
+install-binPROGRAMS: $(bin_PROGRAMS)
+	@$(NORMAL_INSTALL)
+	test -z "$(bindir)" || $(MKDIR_P) "$(DESTDIR)$(bindir)"
+	@list='$(bin_PROGRAMS)'; test -n "$(bindir)" || list=; \
+	for p in $$list; do echo "$$p $$p"; done | \
+	sed 's/$(EXEEXT)$$//' | \
+	while read p p1; do if test -f $$p; \
+	  then echo "$$p"; echo "$$p"; else :; fi; \
+	done | \
+	sed -e 'p;s,.*/,,;n;h' -e 's|.*|.|' \
+	    -e 'p;x;s,.*/,,;s/$(EXEEXT)$$//;$(transform);s/$$/$(EXEEXT)/' | \
+	sed 'N;N;N;s,\n, ,g' | \
+	$(AWK) 'BEGIN { files["."] = ""; dirs["."] = 1 } \
+	  { d=$$3; if (dirs[d] != 1) { print "d", d; dirs[d] = 1 } \
+	    if ($$2 == $$4) files[d] = files[d] " " $$1; \
+	    else { print "f", $$3 "/" $$4, $$1; } } \
+	  END { for (d in files) print "f", d, files[d] }' | \
+	while read type dir files; do \
+	    if test "$$dir" = .; then dir=; else dir=/$$dir; fi; \
+	    test -z "$$files" || { \
+	      echo " $(INSTALL_PROGRAM_ENV) $(INSTALL_PROGRAM) $$files '$(DESTDIR)$(bindir)$$dir'"; \
+	      $(INSTALL_PROGRAM_ENV) $(INSTALL_PROGRAM) $$files "$(DESTDIR)$(bindir)$$dir" || exit $$?; \
+	    } \
+	; done
+
+uninstall-binPROGRAMS:
+	@$(NORMAL_UNINSTALL)
+	@list='$(bin_PROGRAMS)'; test -n "$(bindir)" || list=; \
+	files=`for p in $$list; do echo "$$p"; done | \
+	  sed -e 'h;s,^.*/,,;s/$(EXEEXT)$$//;$(transform)' \
+	      -e 's/$$/$(EXEEXT)/' `; \
+	test -n "$$list" || exit 0; \
+	echo " ( cd '$(DESTDIR)$(bindir)' && rm -f" $$files ")"; \
+	cd "$(DESTDIR)$(bindir)" && rm -f $$files
+
+clean-binPROGRAMS:
+	-test -z "$(bin_PROGRAMS)" || rm -f $(bin_PROGRAMS)
+stressapptest$(EXEEXT): $(stressapptest_OBJECTS) $(stressapptest_DEPENDENCIES) 
+	@rm -f stressapptest$(EXEEXT)
+	$(CXXLINK) $(stressapptest_OBJECTS) $(stressapptest_LDADD) $(LIBS)
+
+mostlyclean-compile:
+	-rm -f *.$(OBJEXT)
+
+distclean-compile:
+	-rm -f *.tab.c
+
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/adler32memcpy.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/disk_blocks.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/error_diag.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/finelock_queue.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/logger.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/main.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/os.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/os_factory.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pattern.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/queue.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sat.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sat_factory.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/worker.Po@am__quote@
+
+.cc.o:
+@am__fastdepCXX_TRUE@	$(CXXCOMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ $<
+@am__fastdepCXX_TRUE@	$(am__mv) $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Po
+@AMDEP_TRUE@@am__fastdepCXX_FALSE@	source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCXX_FALSE@	DEPDIR=$(DEPDIR) $(CXXDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCXX_FALSE@	$(CXXCOMPILE) -c -o $@ $<
+
+.cc.obj:
+@am__fastdepCXX_TRUE@	$(CXXCOMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ `$(CYGPATH_W) '$<'`
+@am__fastdepCXX_TRUE@	$(am__mv) $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Po
+@AMDEP_TRUE@@am__fastdepCXX_FALSE@	source='$<' object='$@' libtool=no @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCXX_FALSE@	DEPDIR=$(DEPDIR) $(CXXDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCXX_FALSE@	$(CXXCOMPILE) -c -o $@ `$(CYGPATH_W) '$<'`
+
+ID: $(HEADERS) $(SOURCES) $(LISP) $(TAGS_FILES)
+	list='$(SOURCES) $(HEADERS) $(LISP) $(TAGS_FILES)'; \
+	unique=`for i in $$list; do \
+	    if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
+	  done | \
+	  $(AWK) '{ files[$$0] = 1; nonempty = 1; } \
+	      END { if (nonempty) { for (i in files) print i; }; }'`; \
+	mkid -fID $$unique
+tags: TAGS
+
+TAGS:  $(HEADERS) $(SOURCES) stressapptest_config.h.in $(TAGS_DEPENDENCIES) \
+		$(TAGS_FILES) $(LISP)
+	set x; \
+	here=`pwd`; \
+	list='$(SOURCES) $(HEADERS) stressapptest_config.h.in $(LISP) $(TAGS_FILES)'; \
+	unique=`for i in $$list; do \
+	    if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
+	  done | \
+	  $(AWK) '{ files[$$0] = 1; nonempty = 1; } \
+	      END { if (nonempty) { for (i in files) print i; }; }'`; \
+	shift; \
+	if test -z "$(ETAGS_ARGS)$$*$$unique"; then :; else \
+	  test -n "$$unique" || unique=$$empty_fix; \
+	  if test $$# -gt 0; then \
+	    $(ETAGS) $(ETAGSFLAGS) $(AM_ETAGSFLAGS) $(ETAGS_ARGS) \
+	      "$$@" $$unique; \
+	  else \
+	    $(ETAGS) $(ETAGSFLAGS) $(AM_ETAGSFLAGS) $(ETAGS_ARGS) \
+	      $$unique; \
+	  fi; \
+	fi
+ctags: CTAGS
+CTAGS:  $(HEADERS) $(SOURCES) stressapptest_config.h.in $(TAGS_DEPENDENCIES) \
+		$(TAGS_FILES) $(LISP)
+	list='$(SOURCES) $(HEADERS) stressapptest_config.h.in $(LISP) $(TAGS_FILES)'; \
+	unique=`for i in $$list; do \
+	    if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
+	  done | \
+	  $(AWK) '{ files[$$0] = 1; nonempty = 1; } \
+	      END { if (nonempty) { for (i in files) print i; }; }'`; \
+	test -z "$(CTAGS_ARGS)$$unique" \
+	  || $(CTAGS) $(CTAGSFLAGS) $(AM_CTAGSFLAGS) $(CTAGS_ARGS) \
+	     $$unique
+
+GTAGS:
+	here=`$(am__cd) $(top_builddir) && pwd` \
+	  && $(am__cd) $(top_srcdir) \
+	  && gtags -i $(GTAGS_ARGS) "$$here"
+
+distclean-tags:
+	-rm -f TAGS ID GTAGS GRTAGS GSYMS GPATH tags
+
+distdir: $(DISTFILES)
+	@srcdirstrip=`echo "$(srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
+	topsrcdirstrip=`echo "$(top_srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
+	list='$(DISTFILES)'; \
+	  dist_files=`for file in $$list; do echo $$file; done | \
+	  sed -e "s|^$$srcdirstrip/||;t" \
+	      -e "s|^$$topsrcdirstrip/|$(top_builddir)/|;t"`; \
+	case $$dist_files in \
+	  */*) $(MKDIR_P) `echo "$$dist_files" | \
+			   sed '/\//!d;s|^|$(distdir)/|;s,/[^/]*$$,,' | \
+			   sort -u` ;; \
+	esac; \
+	for file in $$dist_files; do \
+	  if test -f $$file || test -d $$file; then d=.; else d=$(srcdir); fi; \
+	  if test -d $$d/$$file; then \
+	    dir=`echo "/$$file" | sed -e 's,/[^/]*$$,,'`; \
+	    if test -d "$(distdir)/$$file"; then \
+	      find "$(distdir)/$$file" -type d ! -perm -700 -exec chmod u+rwx {} \;; \
+	    fi; \
+	    if test -d $(srcdir)/$$file && test $$d != $(srcdir); then \
+	      cp -fpR $(srcdir)/$$file "$(distdir)$$dir" || exit 1; \
+	      find "$(distdir)/$$file" -type d ! -perm -700 -exec chmod u+rwx {} \;; \
+	    fi; \
+	    cp -fpR $$d/$$file "$(distdir)$$dir" || exit 1; \
+	  else \
+	    test -f "$(distdir)/$$file" \
+	    || cp -p $$d/$$file "$(distdir)/$$file" \
+	    || exit 1; \
+	  fi; \
+	done
+check-am: all-am
+check: check-am
+all-am: Makefile $(PROGRAMS) stressapptest_config.h
+installdirs:
+	for dir in "$(DESTDIR)$(bindir)"; do \
+	  test -z "$$dir" || $(MKDIR_P) "$$dir"; \
+	done
+install: install-am
+install-exec: install-exec-am
+install-data: install-data-am
+uninstall: uninstall-am
+
+install-am: all-am
+	@$(MAKE) $(AM_MAKEFLAGS) install-exec-am install-data-am
+
+installcheck: installcheck-am
+install-strip:
+	$(MAKE) $(AM_MAKEFLAGS) INSTALL_PROGRAM="$(INSTALL_STRIP_PROGRAM)" \
+	  install_sh_PROGRAM="$(INSTALL_STRIP_PROGRAM)" INSTALL_STRIP_FLAG=-s \
+	  `test -z '$(STRIP)' || \
+	    echo "INSTALL_PROGRAM_ENV=STRIPPROG='$(STRIP)'"` install
+mostlyclean-generic:
+
+clean-generic:
+
+distclean-generic:
+	-test -z "$(CONFIG_CLEAN_FILES)" || rm -f $(CONFIG_CLEAN_FILES)
+	-test . = "$(srcdir)" || test -z "$(CONFIG_CLEAN_VPATH_FILES)" || rm -f $(CONFIG_CLEAN_VPATH_FILES)
+
+maintainer-clean-generic:
+	@echo "This command is intended for maintainers to use"
+	@echo "it deletes files that may require special tools to rebuild."
+clean: clean-am
+
+clean-am: clean-binPROGRAMS clean-generic mostlyclean-am
+
+distclean: distclean-am
+	-rm -rf ./$(DEPDIR)
+	-rm -f Makefile
+distclean-am: clean-am distclean-compile distclean-generic \
+	distclean-hdr distclean-tags
+
+dvi: dvi-am
+
+dvi-am:
+
+html: html-am
+
+html-am:
+
+info: info-am
+
+info-am:
+
+install-data-am:
+
+install-dvi: install-dvi-am
+
+install-dvi-am:
+
+install-exec-am: install-binPROGRAMS
+
+install-html: install-html-am
+
+install-html-am:
+
+install-info: install-info-am
+
+install-info-am:
+
+install-man:
+
+install-pdf: install-pdf-am
+
+install-pdf-am:
+
+install-ps: install-ps-am
+
+install-ps-am:
+
+installcheck-am:
+
+maintainer-clean: maintainer-clean-am
+	-rm -rf ./$(DEPDIR)
+	-rm -f Makefile
+maintainer-clean-am: distclean-am maintainer-clean-generic
+
+mostlyclean: mostlyclean-am
+
+mostlyclean-am: mostlyclean-compile mostlyclean-generic
+
+pdf: pdf-am
+
+pdf-am:
+
+ps: ps-am
+
+ps-am:
+
+uninstall-am: uninstall-binPROGRAMS
+
+.MAKE: all install-am install-strip
+
+.PHONY: CTAGS GTAGS all all-am check check-am clean clean-binPROGRAMS \
+	clean-generic ctags distclean distclean-compile \
+	distclean-generic distclean-hdr distclean-tags distdir dvi \
+	dvi-am html html-am info info-am install install-am \
+	install-binPROGRAMS install-data install-data-am install-dvi \
+	install-dvi-am install-exec install-exec-am install-html \
+	install-html-am install-info install-info-am install-man \
+	install-pdf install-pdf-am install-ps install-ps-am \
+	install-strip installcheck installcheck-am installdirs \
+	maintainer-clean maintainer-clean-generic mostlyclean \
+	mostlyclean-compile mostlyclean-generic pdf pdf-am ps ps-am \
+	tags uninstall uninstall-am uninstall-binPROGRAMS
+
+
+# Tell versions [3.59,3.63) of GNU make to not export all variables.
+# Otherwise a system limit (for SysV at least) may be exceeded.
+.NOEXPORT:
diff --git a/src/adler32memcpy.cc b/src/adler32memcpy.cc
new file mode 100644
index 0000000..69324f7
--- /dev/null
+++ b/src/adler32memcpy.cc
@@ -0,0 +1,406 @@
+// Copyright 2008 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "adler32memcpy.h"
+
+// We are using (a modified form of) adler-32 checksum algorithm instead
+// of CRC since adler-32 is faster than CRC.
+// (Comparison: http://guru.multimedia.cx/crc32-vs-adler32/)
+// This form of adler is bit modified, instead of treating the data in
+// units of bytes, 32-bit data is taken as a unit and two 64-bit
+// checksums are done (we could have one checksum but two checksums
+// make the code run faster).
+
+// Adler-32 implementation:
+//   Data is treated as 1-byte numbers and,
+//   there are two 16-bit numbers a and b
+//   Initialize a with 1 and b with 0.
+//   for each data unit 'd'
+//      a += d
+//      b += a
+//   checksum = a<<16 + b
+//   This sum should never overflow.
+//
+// Adler-64+64 implementation:
+//   (applied in this code)
+//   Data is treated as 32-bit numbers and whole data is separated into two
+//   streams, and hence the two checksums a1, a2, b1 and b2.
+//   Initialize a1 and a2 with 1, b1 and b2 with 0
+//   add first dataunit to a1
+//   add a1 to b1
+//   add second dataunit to a1
+//   add a1 to b1
+//   add third dataunit to a2
+//   add a2 to b2
+//   add fourth dataunit to a2
+//   add a2 to b2
+//   ...
+//   repeat the sequence back for next 4 dataunits
+//
+//   variable A = XMM6 and variable B = XMM7.
+//   (a1 = lower 8 bytes of XMM6 and b1 = lower 8 bytes of XMM7)
+
+// Assumptions
+// 1. size_in_bytes is a multiple of 16.
+// 2. srcmem and dstmem are 16 byte aligned.
+// 3. size_in_bytes is less than 2^19 bytes.
+
+// Assumption 3 ensures that there is no overflow when numbers are being
+// added (we can remove this assumption by doing modulus with a prime
+// number when it is just about to overflow but that would be a very costly
+// exercise)
+
+// Returns true if the checksums are equal.
+bool AdlerChecksum::Equals(const AdlerChecksum &other) const {
+  return ( (a1_ == other.a1_) && (a2_ == other.a2_) &&
+           (b1_ == other.b1_) && (b2_ == other.b2_) );
+}
+
+// Returns string representation of the Adler checksum.
+string AdlerChecksum::ToHexString() const {
+  char buffer[128];
+  snprintf(buffer, sizeof(buffer), "%llx%llx%llx%llx", a1_, a2_, b1_, b2_);
+  return string(buffer);
+}
+
+// Sets components of the Adler checksum.
+void AdlerChecksum::Set(uint64 a1, uint64 a2, uint64 b1, uint64 b2) {
+  a1_ = a1;
+  a2_ = a2;
+  b1_ = b1;
+  b2_ = b2;
+}
+
+// Calculates Adler checksum for supplied data.
+bool CalculateAdlerChecksum(uint64 *data64, unsigned int size_in_bytes,
+                            AdlerChecksum *checksum) {
+  // Use this data wrapper to access memory with 64bit read/write.
+  datacast_t data;
+  unsigned int count = size_in_bytes / sizeof(data);
+
+  if (count > (1U) << 19) {
+    // Size is too large, must be strictly less than 512 KB.
+    return false;
+  }
+
+  uint64 a1 = 1;
+  uint64 a2 = 1;
+  uint64 b1 = 0;
+  uint64 b2 = 0;
+
+  unsigned int i = 0;
+  while (i < count) {
+    // Process 64 bits at a time.
+    data.l64 = data64[i];
+    a1 = a1 + data.l32.l;
+    b1 = b1 + a1;
+    a1 = a1 + data.l32.h;
+    b1 = b1 + a1;
+    i++;
+
+    data.l64 = data64[i];
+    a2 = a2 + data.l32.l;
+    b2 = b2 + a2;
+    a2 = a2 + data.l32.h;
+    b2 = b2 + a2;
+    i++;
+  }
+  checksum->Set(a1, a2, b1, b2);
+  return true;
+}
+
+// C implementation of Adler memory copy.
+bool AdlerMemcpyC(uint64 *dstmem64, uint64 *srcmem64,
+                  unsigned int size_in_bytes, AdlerChecksum *checksum) {
+  // Use this data wrapper to access memory with 64bit read/write.
+  datacast_t data;
+  unsigned int count = size_in_bytes / sizeof(data);
+
+  if (count > ((1U) << 19)) {
+    // Size is too large, must be strictly less than 512 KB.
+    return false;
+  }
+
+  uint64 a1 = 1;
+  uint64 a2 = 1;
+  uint64 b1 = 0;
+  uint64 b2 = 0;
+
+  unsigned int i = 0;
+  while (i < count) {
+    // Process 64 bits at a time.
+    data.l64 = srcmem64[i];
+    a1 = a1 + data.l32.l;
+    b1 = b1 + a1;
+    a1 = a1 + data.l32.h;
+    b1 = b1 + a1;
+    dstmem64[i] = data.l64;
+    i++;
+
+    data.l64 = srcmem64[i];
+    a2 = a2 + data.l32.l;
+    b2 = b2 + a2;
+    a2 = a2 + data.l32.h;
+    b2 = b2 + a2;
+    dstmem64[i] = data.l64;
+    i++;
+  }
+  checksum->Set(a1, a2, b1, b2);
+  return true;
+}
+
+// C implementation of Adler memory copy with some float point ops,
+// attempting to warm up the CPU.
+bool AdlerMemcpyWarmC(uint64 *dstmem64, uint64 *srcmem64,
+                      unsigned int size_in_bytes, AdlerChecksum *checksum) {
+  // Use this data wrapper to access memory with 64bit read/write.
+  datacast_t data;
+  unsigned int count = size_in_bytes / sizeof(data);
+
+  if (count > ((1U) << 19)) {
+    // Size is too large, must be strictly less than 512 KB.
+    return false;
+  }
+
+  uint64 a1 = 1;
+  uint64 a2 = 1;
+  uint64 b1 = 0;
+  uint64 b2 = 0;
+
+  double a = 2.0 * static_cast<double>(srcmem64[0]);
+  double b = 5.0 * static_cast<double>(srcmem64[0]);
+  double c = 7.0 * static_cast<double>(srcmem64[0]);
+  double d = 9.0 * static_cast<double>(srcmem64[0]);
+
+  unsigned int i = 0;
+  while (i < count) {
+    // Process 64 bits at a time.
+    data.l64 = srcmem64[i];
+    a1 = a1 + data.l32.l;
+    b1 = b1 + a1;
+    a1 = a1 + data.l32.h;
+    b1 = b1 + a1;
+    dstmem64[i] = data.l64;
+    i++;
+
+    // Warm cpu up.
+    a = a * b;
+    b = b + c;
+
+    data.l64 = srcmem64[i];
+    a2 = a2 + data.l32.l;
+    b2 = b2 + a2;
+    a2 = a2 + data.l32.h;
+    b2 = b2 + a2;
+    dstmem64[i] = data.l64;
+    i++;
+
+    // Warm cpu up.
+    c = c * d;
+    d = d + d;
+  }
+
+  // Warm cpu up.
+  d = a + b + c + d;
+  if (d == 1.0) {
+    // Reference the result so that it can't be discarded by the compiler.
+    printf("Log: This will probably never happen.\n");
+  }
+
+  checksum->Set(a1, a2, b1, b2);
+  return true;
+}
+
+// x86_64 SSE2 assembly implementation of fast and stressful Adler memory copy.
+bool AdlerMemcpyAsm(uint64 *dstmem64, uint64 *srcmem64,
+                    unsigned int size_in_bytes, AdlerChecksum *checksum) {
+// Use assembly implementation where supported.
+#if defined(STRESSAPPTEST_CPU_X86_64) || defined(STRESSAPPTEST_CPU_I686)
+
+// Pull a bit of tricky preprocessing to make the inline asm both
+// 32 bit and 64 bit.
+#ifdef STRESSAPPTEST_CPU_I686  // Instead of coding both, x86...
+#define rAX "%%eax"
+#define rCX "%%ecx"
+#define rDX "%%edx"
+#define rBX "%%ebx"
+#define rSP "%%esp"
+#define rBP "%%ebp"
+#define rSI "%%esi"
+#define rDI "%%edi"
+#endif
+
+#ifdef STRESSAPPTEST_CPU_X86_64  // ...and x64, we use rXX macros.
+#define rAX "%%rax"
+#define rCX "%%rcx"
+#define rDX "%%rdx"
+#define rBX "%%rbx"
+#define rSP "%%rsp"
+#define rBP "%%rbp"
+#define rSI "%%rsi"
+#define rDI "%%rdi"
+#endif
+
+  // Elements 0 to 3 are used for holding checksum terms a1, a2,
+  // b1, b2 respectively. These elements are filled by asm code.
+  // Elements 4 and 5 are used by asm code to for ANDing MMX data and removing
+  // 2 words from each MMX register (A MMX reg has 4 words, by ANDing we are
+  // setting word index 0 and word index 2 to zero).
+  // Element 6 and 7 are used for setting a1 and a2 to 1.
+  volatile uint64 checksum_arr[] __attribute__ ((aligned(16))) =
+      {0, 0, 0, 0, 0x00000000ffffffffUL, 0x00000000ffffffffUL, 1, 1};
+
+  if ((size_in_bytes >> 19) > 0) {
+    // Size is too large. Must be less than 2^19 bytes = 512 KB.
+    return false;
+  }
+
+  // Number of 32-bit words which are not added to a1/a2 in the main loop.
+  uint32 remaining_words = (size_in_bytes % 48) / 4;
+
+  // Since we are moving 48 bytes at a time number of iterations = total size/48
+  // is value of counter.
+  uint32 num_of_48_byte_units = size_in_bytes / 48;
+
+  asm volatile (
+      // Source address is in ESI (extended source index)
+      // destination is in EDI (extended destination index)
+      // and counter is already in ECX (extended counter
+      // index).
+      "cmp  $0, " rCX ";"   // Compare counter to zero.
+      "jz END;"
+
+      // XMM6 is initialized with 1 and XMM7 with 0.
+      "prefetchnta  0(" rSI ");"
+      "prefetchnta 64(" rSI ");"
+      "movdqu   48(" rAX "), %%xmm6;"
+      "xorps      %%xmm7, %%xmm7;"
+
+      // Start of the loop which copies 48 bytes from source to dst each time.
+      "TOP:\n"
+
+      // Make 6 moves each of 16 bytes from srcmem to XMM registers.
+      // We are using 2 words out of 4 words in each XMM register,
+      // word index 0 and word index 2
+      "movdqa   0(" rSI "), %%xmm0;"
+      "movdqu   4(" rSI "), %%xmm1;"  // Be careful to use unaligned move here.
+      "movdqa  16(" rSI "), %%xmm2;"
+      "movdqu  20(" rSI "), %%xmm3;"
+      "movdqa  32(" rSI "), %%xmm4;"
+      "movdqu  36(" rSI "), %%xmm5;"
+
+      // Move 3 * 16 bytes from XMM registers to dstmem.
+      // Note: this copy must be performed before pinsrw instructions since
+      // they will modify the XMM registers.
+      "movntdq %%xmm0,  0(" rDI ");"
+      "movntdq %%xmm2, 16(" rDI ");"
+      "movntdq %%xmm4, 32(" rDI ");"
+
+      // Sets the word[1] and word[3] of XMM0 to XMM5 to zero.
+      "andps 32(" rAX "), %%xmm0;"
+      "andps 32(" rAX "), %%xmm1;"
+      "andps 32(" rAX "), %%xmm2;"
+      "andps 32(" rAX "), %%xmm3;"
+      "andps 32(" rAX "), %%xmm4;"
+      "andps 32(" rAX "), %%xmm5;"
+
+      // Add XMM0 to XMM6 and then add XMM6 to XMM7.
+      // Repeat this for XMM1, ..., XMM5.
+      // Overflow(for XMM7) can occur only if there are more
+      // than 2^16 additions => more than 2^17 words => more than 2^19 bytes so
+      // if size_in_bytes > 2^19 than overflow occurs.
+      "paddq %%xmm0, %%xmm6;"
+      "paddq %%xmm6, %%xmm7;"
+      "paddq %%xmm1, %%xmm6;"
+      "paddq %%xmm6, %%xmm7;"
+      "paddq %%xmm2, %%xmm6;"
+      "paddq %%xmm6, %%xmm7;"
+      "paddq %%xmm3, %%xmm6;"
+      "paddq %%xmm6, %%xmm7;"
+      "paddq %%xmm4, %%xmm6;"
+      "paddq %%xmm6, %%xmm7;"
+      "paddq %%xmm5, %%xmm6;"
+      "paddq %%xmm6, %%xmm7;"
+
+      // Increment ESI and EDI by 48 bytes and decrement counter by 1.
+      "add $48, " rSI ";"
+      "add $48, " rDI ";"
+      "prefetchnta  0(" rSI ");"
+      "prefetchnta 64(" rSI ");"
+      "dec " rCX ";"
+      "jnz TOP;"
+
+      // Now only remaining_words 32-bit words are left.
+      // make a loop, add first two words to a1 and next two to a2 (just like
+      // above loop, the only extra thing we are doing is rechecking
+      // rDX (=remaining_words) everytime we add a number to a1/a2.
+      "REM_IS_STILL_NOT_ZERO:\n"
+      // Unless remaining_words becomes less than 4 words(16 bytes)
+      // there is not much issue and remaining_words will always
+      // be a multiple of four by assumption.
+      "cmp $4, " rDX ";"
+      // In case for some weird reasons if remaining_words becomes
+      // less than 4 but not zero then also break the code and go off to END.
+      "jl END;"
+      // Otherwise just go on and copy data in chunks of 4-words at a time till
+      // whole data (<48 bytes) is copied.
+      "movdqa  0(" rSI "), %%xmm0;"    // Copy next 4-words to XMM0 and to XMM1.
+
+      "movdqa  0(" rSI "), %%xmm5;"    // Accomplish movdqu 4(%rSI) without
+      "pshufd $0x39, %%xmm5, %%xmm1;"  // indexing off memory boundary.
+
+      "movntdq %%xmm0,  0(" rDI ");"   // Copy 4-words to destination.
+      "andps  32(" rAX "), %%xmm0;"
+      "andps  32(" rAX "), %%xmm1;"
+      "paddq     %%xmm0, %%xmm6;"
+      "paddq     %%xmm6, %%xmm7;"
+      "paddq     %%xmm1, %%xmm6;"
+      "paddq     %%xmm6, %%xmm7;"
+      "add $16, " rSI ";"
+      "add $16, " rDI ";"
+      "sub $4, " rDX ";"
+      // Decrement %rDX by 4 since %rDX is number of 32-bit
+      // words left after considering all 48-byte units.
+      "jmp REM_IS_STILL_NOT_ZERO;"
+
+      "END:\n"
+      // Report checksum values A and B (both right now are two concatenated
+      // 64 bit numbers and have to be converted to 64 bit numbers)
+      // seems like Adler128 (since size of each part is 4 byte rather than
+      // 1 byte).
+      "movdqa %%xmm6,   0(" rAX ");"
+      "movdqa %%xmm7,  16(" rAX ");"
+      "sfence;"
+
+      // No output registers.
+      :
+      // Input registers.
+      : "S" (srcmem64), "D" (dstmem64), "a" (checksum_arr),
+        "c" (num_of_48_byte_units), "d" (remaining_words)
+  );  // asm.
+
+  if (checksum != NULL) {
+    checksum->Set(checksum_arr[0], checksum_arr[1],
+                  checksum_arr[2], checksum_arr[3]);
+  }
+
+  // Everything went fine, so return true (this does not mean
+  // that there is no problem with memory this just mean that data was copied
+  // from src to dst and checksum was calculated successfully).
+  return true;
+#else
+  // Fall back to C implementation for anything else.
+  return AdlerMemcpyWarmC(dstmem64, srcmem64, size_in_bytes, checksum);
+#endif
+}
diff --git a/src/adler32memcpy.h b/src/adler32memcpy.h
new file mode 100644
index 0000000..d053340
--- /dev/null
+++ b/src/adler32memcpy.h
@@ -0,0 +1,59 @@
+// Copyright 2008 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef STRESSAPPTEST_ADLER32MEMCPY_H_
+#define STRESSAPPTEST_ADLER32MEMCPY_H_
+
+#include <string>
+#include "sattypes.h"
+
+// Encapsulation for Adler checksum. Please see adler32memcpy.cc for more
+// detail on the adler checksum algorithm.
+class AdlerChecksum {
+ public:
+  AdlerChecksum() {}
+  ~AdlerChecksum() {}
+  // Returns true if the checksums are equal.
+  bool Equals(const AdlerChecksum &other) const;
+  // Returns string representation of the Adler checksum
+  string ToHexString() const;
+  // Sets components of the Adler checksum.
+  void Set(uint64 a1, uint64 a2, uint64 b1, uint64 b2);
+
+ private:
+  // Components of Adler checksum.
+  uint64 a1_, a2_, b1_, b2_;
+
+  DISALLOW_COPY_AND_ASSIGN(AdlerChecksum);
+};
+
+// Calculates Adler checksum for supplied data.
+bool CalculateAdlerChecksum(uint64 *data64, unsigned int size_in_bytes,
+                            AdlerChecksum *checksum);
+
+// C implementation of Adler memory copy.
+bool AdlerMemcpyC(uint64 *dstmem64, uint64 *srcmem64,
+                    unsigned int size_in_bytes, AdlerChecksum *checksum);
+
+// C implementation of Adler memory copy with some float point ops,
+// attempting to warm up the CPU.
+bool AdlerMemcpyWarmC(uint64 *dstmem64, uint64 *srcmem64,
+                      unsigned int size_in_bytes, AdlerChecksum *checksum);
+
+// x86_64 SSE2 assembly implementation of fast and stressful Adler memory copy.
+bool AdlerMemcpyAsm(uint64 *dstmem64, uint64 *srcmem64,
+                    unsigned int size_in_bytes, AdlerChecksum *checksum);
+
+
+#endif  // STRESSAPPTEST_ADLER32MEMCPY_H_
diff --git a/src/disk_blocks.cc b/src/disk_blocks.cc
new file mode 100644
index 0000000..c7860b0
--- /dev/null
+++ b/src/disk_blocks.cc
@@ -0,0 +1,313 @@
+// Copyright 2008 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Thread-safe container of disk blocks
+
+#include <utility>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "disk_blocks.h"
+
+DiskBlockTable::DiskBlockTable() {
+  nelems_ = 0;
+  pthread_mutex_init(&data_mutex_, NULL);
+  pthread_mutex_init(&parameter_mutex_, NULL);
+  pthread_cond_init(&data_condition_, NULL);
+}
+
+DiskBlockTable::~DiskBlockTable() {
+  CleanTable();
+  pthread_mutex_destroy(&data_mutex_);
+  pthread_mutex_destroy(&parameter_mutex_);
+  pthread_cond_destroy(&data_condition_);
+}
+
+void DiskBlockTable::CleanTable() {
+  pthread_mutex_lock(&data_mutex_);
+  for (map<int64, StorageData*>::iterator it =
+           addr_to_block_.begin(); it != addr_to_block_.end(); ++it) {
+    delete it->second;
+  }
+  addr_to_block_.erase(addr_to_block_.begin(), addr_to_block_.end());
+  nelems_ = 0;
+  pthread_cond_broadcast(&data_condition_);
+  pthread_mutex_unlock(&data_mutex_);
+}
+
+// 64-bit non-negative random number generator.  Stolen from
+// depot/google3/base/tracecontext_unittest.cc.
+int64 DiskBlockTable::Random64() {
+  int64 x = random();
+  x = (x << 30) ^ random();
+  x = (x << 30) ^ random();
+  if (x >= 0)
+    return x;
+  else
+    return -x;
+}
+
+int64 DiskBlockTable::NumElems() {
+  unsigned int nelems;
+  pthread_mutex_lock(&data_mutex_);
+  nelems = nelems_;
+  pthread_mutex_unlock(&data_mutex_);
+  return nelems;
+}
+
+void DiskBlockTable::InsertOnStructure(BlockData *block) {
+  int64 address = block->GetAddress();
+  StorageData *sd = new StorageData();
+  sd->block = block;
+  sd->pos = nelems_;
+  // Creating new block ...
+  pthread_mutex_lock(&data_mutex_);
+  if (pos_to_addr_.size() <= nelems_) {
+    pos_to_addr_.insert(pos_to_addr_.end(), address);
+  } else {
+    pos_to_addr_[nelems_] = address;
+  }
+  addr_to_block_.insert(std::make_pair(address, sd));
+  nelems_++;
+  pthread_cond_broadcast(&data_condition_);
+  pthread_mutex_unlock(&data_mutex_);
+}
+
+int DiskBlockTable::RemoveBlock(BlockData *block) {
+  // For write threads, check the reference counter and remove
+  // it from the structure.
+  int64 address = block->GetAddress();
+  AddrToBlockMap::iterator it = addr_to_block_.find(address);
+  int ret = 1;
+  if (it != addr_to_block_.end()) {
+    int curr_pos = it->second->pos;
+    int last_pos = nelems_ - 1;
+    AddrToBlockMap::iterator last_it = addr_to_block_.find(
+        pos_to_addr_[last_pos]);
+    sat_assert(nelems_ > 0);
+    sat_assert(last_it != addr_to_block_.end());
+    // Everything is fine, updating ...
+    pthread_mutex_lock(&data_mutex_);
+    pos_to_addr_[curr_pos] = pos_to_addr_[last_pos];
+    last_it->second->pos = curr_pos;
+    delete it->second;
+    addr_to_block_.erase(it);
+    nelems_--;
+    block->DecreaseReferenceCounter();
+    if (block->GetReferenceCounter() == 0)
+      delete block;
+    pthread_cond_broadcast(&data_condition_);
+    pthread_mutex_unlock(&data_mutex_);
+  } else {
+    ret = 0;
+  }
+  return ret;
+}
+
+int DiskBlockTable::ReleaseBlock(BlockData *block) {
+  // If is a random thread, just check the reference counter.
+  int ret = 1;
+  pthread_mutex_lock(&data_mutex_);
+  int references = block->GetReferenceCounter();
+  if (references > 0) {
+    if (references == 1)
+      delete block;
+    else
+      block->DecreaseReferenceCounter();
+  } else {
+    ret = 0;
+  }
+  pthread_mutex_unlock(&data_mutex_);
+  return ret;
+}
+
+BlockData *DiskBlockTable::GetRandomBlock() {
+  struct timespec ts;
+  struct timeval tp;
+  int result = 0;
+  gettimeofday(&tp, NULL);
+  ts.tv_sec  = tp.tv_sec;
+  ts.tv_nsec = tp.tv_usec * 1000;
+  ts.tv_sec += 2;  // Wait for 2 seconds.
+  pthread_mutex_lock(&data_mutex_);
+  while (!nelems_ && result != ETIMEDOUT) {
+    result = pthread_cond_timedwait(&data_condition_, &data_mutex_, &ts);
+  }
+  if (result == ETIMEDOUT) {
+    pthread_mutex_unlock(&data_mutex_);
+    return NULL;
+  } else {
+    int64 random_number = Random64();
+    int64 random_pos = random_number % nelems_;
+    int64 address = pos_to_addr_[random_pos];
+    AddrToBlockMap::const_iterator it = addr_to_block_.find(address);
+    sat_assert(it != addr_to_block_.end());
+    BlockData *b = it->second->block;
+    // A block is returned only if its content is written on disk.
+    if (b->BlockIsInitialized()) {
+      b->IncreaseReferenceCounter();
+    } else {
+      b = NULL;
+    }
+    pthread_mutex_unlock(&data_mutex_);
+    return b;
+  }
+}
+
+void DiskBlockTable::SetParameters(
+    int sector_size, int write_block_size, int64 device_sectors,
+    int64 segment_size, string device_name) {
+  pthread_mutex_lock(&parameter_mutex_);
+  sector_size_ = sector_size;
+  write_block_size_ = write_block_size;
+  device_sectors_ = device_sectors;
+  segment_size_ = segment_size;
+  device_name_ = device_name;
+  CleanTable();
+  pthread_mutex_unlock(&parameter_mutex_);
+}
+
+BlockData *DiskBlockTable::GetUnusedBlock(int64 segment) {
+  int64 sector = 0;
+  BlockData *block = new BlockData();
+
+  bool good_sequence = false;
+  int num_sectors;
+
+  if (block == NULL) {
+    logprintf(0, "Process Error: Unable to allocate memory "
+              "for sector data for disk %s.\n", device_name_.c_str());
+    return NULL;
+  }
+
+  pthread_mutex_lock(&parameter_mutex_);
+
+  sat_assert(device_sectors_ != 0);
+
+  // Align the first sector with the beginning of a write block
+  num_sectors = write_block_size_ / sector_size_;
+
+  for (int i = 0; i < kBlockRetry && !good_sequence; i++) {
+    good_sequence = true;
+
+    // Use the entire disk or a small segment of the disk to allocate the first
+    // sector in the block from.
+
+    if (segment_size_ == -1) {
+      sector = (Random64() & 0x7FFFFFFFFFFFFFFFLL) % (
+          device_sectors_ / num_sectors);
+      sector *= num_sectors;
+    } else {
+      sector = (Random64() & 0x7FFFFFFFFFFFFFFFLL) % (
+          segment_size_ / num_sectors);
+      sector *= num_sectors;
+      sector += segment * segment_size_;
+
+      // Make sure the block is within the segment.
+      if (sector + num_sectors > (segment + 1) * segment_size_) {
+        good_sequence = false;
+        continue;
+      }
+    }
+    // Make sure the entire block is in range.
+    if (sector + num_sectors > device_sectors_) {
+      good_sequence = false;
+      continue;
+    }
+    // Check to see if the block is free. Since the blocks are
+    // now aligned to the write_block_size, it is not necessary
+    // to check each sector, just the first block (a sector
+    // overlap will never occur).
+
+    pthread_mutex_lock(&data_mutex_);
+    if (addr_to_block_.find(sector) != addr_to_block_.end()) {
+      good_sequence = false;
+    }
+    pthread_mutex_unlock(&data_mutex_);
+  }
+
+  if (good_sequence) {
+    block->SetParameters(sector, write_block_size_);
+    block->IncreaseReferenceCounter();
+    InsertOnStructure(block);
+  } else {
+    // No contiguous sequence of num_sectors sectors was found within
+    // kBlockRetry iterations so return an error value.
+    delete block;
+    block = NULL;
+  }
+  pthread_mutex_unlock(&parameter_mutex_);
+
+  return block;
+}
+
+// BlockData
+
+BlockData::BlockData() {
+  addr_ = 0;
+  size_ = 0;
+  references_ = 0;
+  initialized_ = false;
+  pthread_mutex_init(&data_mutex_, NULL);
+}
+
+BlockData::~BlockData() {
+  pthread_mutex_destroy(&data_mutex_);
+}
+
+void BlockData::SetParameters(int64 address, int64 size) {
+  addr_ = address;
+  size_ = size;
+}
+
+void BlockData::IncreaseReferenceCounter() {
+  references_++;
+}
+
+void BlockData::DecreaseReferenceCounter() {
+  references_--;
+}
+
+int BlockData::GetReferenceCounter() {
+  return references_;
+}
+
+void BlockData::SetBlockAsInitialized() {
+  pthread_mutex_lock(&data_mutex_);
+  initialized_ = true;
+  pthread_mutex_unlock(&data_mutex_);
+}
+
+bool BlockData::BlockIsInitialized() {
+  pthread_mutex_lock(&data_mutex_);
+  bool initialized = initialized_;
+  pthread_mutex_unlock(&data_mutex_);
+  return initialized;
+}
+
+int64 BlockData::GetAddress() {
+  return addr_;
+}
+
+int64 BlockData::GetSize() {
+  return size_;
+}
+
+Pattern *BlockData::GetPattern() {
+  return pattern_;
+}
+
+void BlockData::SetPattern(Pattern *p) {
+  pattern_ = p;
+}
diff --git a/src/disk_blocks.h b/src/disk_blocks.h
new file mode 100644
index 0000000..cb634c9
--- /dev/null
+++ b/src/disk_blocks.h
@@ -0,0 +1,115 @@
+// Copyright 2008 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Interface for a thread-safe container of disk blocks
+
+#ifndef STRESSAPPTEST_DISK_BLOCKS_H_
+#define STRESSAPPTEST_DISK_BLOCKS_H_
+
+#include <sys/types.h>
+#include <pthread.h>
+#include <time.h>
+#include <sys/time.h>
+#include <errno.h>
+#include <map>
+#include <vector>
+#include <string>
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "pattern.h"
+
+// Data about a block written to disk so that it can be verified later.
+class BlockData {
+ public:
+  BlockData();
+  ~BlockData();
+  void SetParameters(int64 address, int64 size);
+  void IncreaseReferenceCounter();
+  void DecreaseReferenceCounter();
+  int GetReferenceCounter();
+  void SetBlockAsInitialized();
+  bool BlockIsInitialized();
+  int64 GetAddress();
+  int64 GetSize();
+  void SetPattern(Pattern *p);
+  Pattern *GetPattern();
+ protected:
+  int64 addr_;         // address of first sector in block
+  int64 size_;         // size of block
+  int references_;      // reference counter
+  bool initialized_;     // flag indicating the block was written on disk
+  Pattern *pattern_;
+  pthread_mutex_t data_mutex_;
+  DISALLOW_COPY_AND_ASSIGN(BlockData);
+};
+
+// Disk Block table - store data from blocks to be write / read by
+// a DiskThread
+class DiskBlockTable {
+ public:
+  DiskBlockTable();
+  virtual ~DiskBlockTable();
+
+  // Get Number of elements stored on table
+  int64 NumElems();
+  // Clean all table data
+  void CleanTable();
+  // Get a random block from the list. Only returns if a element
+  // is available (consider that other thread must have added them.
+  BlockData *GetRandomBlock();
+  // Set all initial parameters. Assumes all existent data is
+  // invalid and, therefore, must be removed.
+  void SetParameters(int sector_size, int write_block_size,
+                     int64 device_sectors,
+                     int64 segment_size,
+                     string device_name);
+  // Return a new block in a unused address.
+  BlockData *GetUnusedBlock(int64 segment);
+  // Remove block from structure (called by write threads)
+  int RemoveBlock(BlockData *block);
+  // Release block to be erased (called by random threads)
+  int ReleaseBlock(BlockData *block);
+
+ protected:
+
+  void InsertOnStructure(BlockData *block);
+  //  Generate a random 64-bit integer (virtual so it could be
+  //  override by the tests)
+  virtual int64 Random64();
+
+  struct StorageData {
+    BlockData *block;
+    int pos;
+  };
+
+  static const int kBlockRetry = 100;       // Number of retries to allocate
+                                            // sectors.
+
+  typedef map<int64, StorageData*> AddrToBlockMap;
+  typedef vector<int64> PosToAddrVector;
+  PosToAddrVector pos_to_addr_;
+  AddrToBlockMap addr_to_block_;
+  uint64 nelems_;
+  int sector_size_;          // Sector size, in bytes
+  int write_block_size_;     // Block size, in bytes
+  string device_name_;       // Device name
+  int64 device_sectors_;     // Number of sectors in device
+  int64 segment_size_;       // Segment size, in bytes
+  pthread_mutex_t data_mutex_;
+  pthread_cond_t data_condition_;
+  pthread_mutex_t parameter_mutex_;
+  DISALLOW_COPY_AND_ASSIGN(DiskBlockTable);
+};
+
+#endif  // STRESSAPPTEST_BLOCKS_H_
diff --git a/src/error_diag.cc b/src/error_diag.cc
new file mode 100644
index 0000000..53f056f
--- /dev/null
+++ b/src/error_diag.cc
@@ -0,0 +1,317 @@
+// Copyright 2008 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// error_diag.cc: Collects device errors for analysis to more accurately
+//                pin-point failed component.
+
+#include <set>
+#include <list>
+#include <map>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "error_diag.h"
+#include "sattypes.h"
+
+
+// DeviceTree constructor.
+DeviceTree::DeviceTree(string name)
+  : parent_(0), name_(name) {
+  pthread_mutex_init(&device_tree_mutex_, NULL);
+}
+
+// DeviceTree destructor.
+DeviceTree::~DeviceTree() {
+  // Deallocate subtree devices.
+  for (std::map<string, DeviceTree*>::iterator itr = subdevices_.begin();
+      itr != subdevices_.end();
+      ++itr) {
+    delete itr->second;
+  }
+  // Deallocate device errors.
+  for (std::list<ErrorInstance*>::iterator itr = errors_.begin();
+      itr != errors_.end();
+      ++itr) {
+    delete (*itr);
+  }
+  pthread_mutex_destroy(&device_tree_mutex_);
+}
+
+// Atomically find named device in sub device tree.
+// Returns 0 if not found
+DeviceTree *DeviceTree::FindInSubTree(string name) {
+  DeviceTree *ret;
+  pthread_mutex_lock(&device_tree_mutex_);
+  ret = UnlockedFindInSubTree(name);
+  pthread_mutex_unlock(&device_tree_mutex_);
+  return ret;
+}
+
+// Find named device in sub device tree (Non-atomic).
+// Returns 0 if not found
+DeviceTree *DeviceTree::UnlockedFindInSubTree(string name) {
+  std::map<string, DeviceTree*>::iterator itr = subdevices_.find(name);
+  if (itr != subdevices_.end()) {
+    return itr->second;
+  } else {
+    // Search sub-tree.
+    for (std::map<string, DeviceTree*>::iterator itr = subdevices_.begin();
+        itr != subdevices_.end();
+        ++itr) {
+      DeviceTree *result = itr->second->UnlockedFindInSubTree(name);
+      if (result != 0)
+        return result;
+    }
+    return 0;
+  }
+}
+
+// Atomically add error instance to device.
+void DeviceTree::AddErrorInstance(ErrorInstance *error_instance) {
+  pthread_mutex_lock(&device_tree_mutex_);
+  errors_.push_back(error_instance);
+  pthread_mutex_unlock(&device_tree_mutex_);
+}
+
+// Find or add queried device as necessary.
+DeviceTree *DeviceTree::FindOrAddDevice(string name) {
+  // Assume named device does not exist and try to insert the device anyway.
+  // No-op if named device already exists.
+  InsertSubDevice(name);
+  // Find and return sub device pointer.
+  return FindInSubTree(name);
+}
+
+// Pretty prints device tree.
+void DeviceTree::PrettyPrint(string spacer) {
+  for (std::map<string, DeviceTree*>::iterator itr = subdevices_.begin();
+      itr != subdevices_.end();
+      ++itr) {
+    printf("%s%s\n", spacer.c_str(), itr->first.c_str());
+    itr->second->PrettyPrint(spacer+spacer);
+  }
+}
+
+// Atomically add sub device.
+// No-op if named device already exists.
+void DeviceTree::InsertSubDevice(string name) {
+  pthread_mutex_lock(&device_tree_mutex_);
+  if (UnlockedFindInSubTree(name) != 0) {
+    pthread_mutex_unlock(&device_tree_mutex_);
+    return;
+  }
+  subdevices_[name] = new DeviceTree(name);
+  subdevices_[name]->parent_ = this;
+  pthread_mutex_unlock(&device_tree_mutex_);
+}
+
+
+// Returns true of any error associated with this device is fatal.
+bool DeviceTree::KnownBad() {
+  pthread_mutex_lock(&device_tree_mutex_);
+  for (std::list<ErrorInstance*>::iterator itr = errors_.begin();
+      itr != errors_.end();
+      ++itr) {
+    if ((*itr)->severity_ == SAT_ERROR_FATAL) {
+      pthread_mutex_unlock(&device_tree_mutex_);
+      return true;
+    }
+  }
+  pthread_mutex_unlock(&device_tree_mutex_);
+  return false;
+}
+
+
+// ErrorDiag constructor.
+ErrorDiag::ErrorDiag() {
+  os_ = 0;
+  system_tree_root_ = 0;
+}
+
+// ErrorDiag destructor.
+ErrorDiag::~ErrorDiag() {
+  if (system_tree_root_)
+    delete system_tree_root_;
+}
+
+// Set platform specific handle and initialize device tree.
+// Returns false on error. true otherwise.
+bool ErrorDiag::set_os(OsLayer *os) {
+  os_ = os;
+  return(InitializeDeviceTree());
+}
+
+// Create and initialize system device tree.
+// Returns false on error. true otherwise.
+bool ErrorDiag::InitializeDeviceTree() {
+  system_tree_root_ = new DeviceTree("system_root");
+  if (!system_tree_root_)
+    return false;
+  return true;
+}
+
+// Logs info about a CECC.
+// Returns -1 on error, 1 if diagnoser reports error externally; 0 otherwise.
+int ErrorDiag::AddCeccError(string dimm_string) {
+  DeviceTree *dimm_device = system_tree_root_->FindOrAddDevice(dimm_string);
+  ECCErrorInstance *error = new ECCErrorInstance;
+  if (!error)
+    return -1;
+  error->severity_ = SAT_ERROR_CORRECTABLE;
+  dimm_device->AddErrorInstance(error);
+  return 0;
+}
+
+// Logs info about a UECC.
+// Returns -1 on error, 1 if diagnoser reports error externally; 0 otherwise.
+int ErrorDiag::AddUeccError(string dimm_string) {
+  DeviceTree *dimm_device = system_tree_root_->FindOrAddDevice(dimm_string);
+  ECCErrorInstance *error = new ECCErrorInstance;
+  if (!error)
+    return -1;
+  error->severity_ = SAT_ERROR_FATAL;
+  dimm_device->AddErrorInstance(error);
+  return 0;
+}
+
+// Logs info about a miscompare.
+// Returns -1 on error, 1 if diagnoser reports error externally; 0 otherwise.
+int ErrorDiag::AddMiscompareError(string dimm_string, uint64 addr, int count) {
+  DeviceTree *dimm_device = system_tree_root_->FindOrAddDevice(dimm_string);
+  MiscompareErrorInstance *error = new MiscompareErrorInstance;
+  if (!error)
+    return -1;
+  error->severity_ = SAT_ERROR_FATAL;
+  error->addr_ = addr;
+  dimm_device->AddErrorInstance(error);
+  os_->ErrorReport(dimm_string.c_str(), "miscompare", count);
+  return 1;
+}
+
+// Utility Function to translate a virtual address to DIMM number.
+// Returns -1 on error, 1 if diagnoser reports error externally; 0 otherwise.
+string ErrorDiag::AddressToDimmString(OsLayer *os, void *addr, int offset) {
+  char dimm_string[256] = "";
+  char *vbyteaddr = reinterpret_cast<char*>(addr) + offset;
+  uint64 paddr = os->VirtualToPhysical(vbyteaddr);
+  os->FindDimm(paddr, dimm_string, sizeof(dimm_string));
+  return string(dimm_string);
+}
+
+// Info about a miscompare from a drive.
+// Returns -1 on error, 1 if diagnoser reports error externally; 0 otherwise.
+int ErrorDiag::AddHDDMiscompareError(string devicename, int block, int offset,
+                                     void *src_addr, void *dst_addr) {
+  bool mask_hdd_error = false;
+
+  HDDMiscompareErrorInstance *error = new HDDMiscompareErrorInstance;
+  if (!error)
+    return -1;
+
+  error->addr_ = reinterpret_cast<uint64>(src_addr);
+  error->addr2_ = reinterpret_cast<uint64>(dst_addr);
+  error->offset_ = offset;
+  error->block_ = block;
+
+  string src_dimm = AddressToDimmString(os_, src_addr, offset);
+  string dst_dimm = AddressToDimmString(os_, dst_addr, offset);
+
+  // DIMM name look up success
+  if (src_dimm.compare("DIMM Unknown")) {
+    // Add src DIMM as possible miscompare cause.
+    DeviceTree *src_dimm_dev = system_tree_root_->FindOrAddDevice(src_dimm);
+    error->causes_.insert(src_dimm_dev);
+    if (src_dimm_dev->KnownBad()) {
+      mask_hdd_error = true;
+      logprintf(5, "Log: supressed %s miscompare report: "
+                "known bad source: %s\n", devicename.c_str(), src_dimm.c_str());
+    }
+  }
+  if (dst_dimm.compare("DIMM Unknown")) {
+    // Add dst DIMM as possible miscompare cause.
+    DeviceTree *dst_dimm_dev = system_tree_root_->FindOrAddDevice(dst_dimm);
+    error->causes_.insert(dst_dimm_dev);
+    if (dst_dimm_dev->KnownBad()) {
+      mask_hdd_error = true;
+      logprintf(5, "Log: supressed %s miscompare report: "
+                "known bad destination: %s\n", devicename.c_str(),
+                dst_dimm.c_str());
+    }
+  }
+
+  DeviceTree *hdd_dev = system_tree_root_->FindOrAddDevice(devicename);
+  hdd_dev->AddErrorInstance(error);
+
+  // HDD error was not masked by bad DIMMs: report bad HDD.
+  if (!mask_hdd_error) {
+    os_->ErrorReport(devicename.c_str(), "miscompare", 1);
+    error->severity_ = SAT_ERROR_FATAL;
+    return 1;
+  }
+  return 0;
+}
+
+// Info about a sector tag miscompare from a drive.
+// Returns -1 on error, 1 if diagnoser reports error externally; 0 otherwise.
+int ErrorDiag::AddHDDSectorTagError(string devicename, int block, int offset,
+                                    int sector, void *src_addr,
+                                    void *dst_addr) {
+  bool mask_hdd_error = false;
+
+  HDDSectorTagErrorInstance *error = new HDDSectorTagErrorInstance;
+  if (!error)
+    return -1;
+
+  error->addr_ = reinterpret_cast<uint64>(src_addr);
+  error->addr2_ = reinterpret_cast<uint64>(dst_addr);
+  error->sector_ = sector;
+  error->block_ = block;
+
+  string src_dimm = AddressToDimmString(os_, src_addr, offset);
+  string dst_dimm = AddressToDimmString(os_, dst_addr, offset);
+
+  // DIMM name look up success
+  if (src_dimm.compare("DIMM Unknown")) {
+    // Add src DIMM as possible miscompare cause.
+    DeviceTree *src_dimm_dev = system_tree_root_->FindOrAddDevice(src_dimm);
+    error->causes_.insert(src_dimm_dev);
+    if (src_dimm_dev->KnownBad()) {
+      mask_hdd_error = true;
+      logprintf(5, "Log: supressed %s sector tag error report: "
+                "known bad source: %s\n", devicename.c_str(), src_dimm.c_str());
+    }
+  }
+  if (dst_dimm.compare("DIMM Unknown")) {
+    // Add dst DIMM as possible miscompare cause.
+    DeviceTree *dst_dimm_dev = system_tree_root_->FindOrAddDevice(dst_dimm);
+    error->causes_.insert(dst_dimm_dev);
+    if (dst_dimm_dev->KnownBad()) {
+      mask_hdd_error = true;
+      logprintf(5, "Log: supressed %s sector tag error report: "
+                "known bad destination: %s\n", devicename.c_str(),
+                dst_dimm.c_str());
+    }
+  }
+
+  DeviceTree *hdd_dev = system_tree_root_->FindOrAddDevice(devicename);
+  hdd_dev->AddErrorInstance(error);
+
+  // HDD error was not masked by bad DIMMs: report bad HDD.
+  if (!mask_hdd_error) {
+    os_->ErrorReport(devicename.c_str(), "sector", 1);
+    error->severity_ = SAT_ERROR_FATAL;
+    return 1;
+  }
+  return 0;
+}
diff --git a/src/error_diag.h b/src/error_diag.h
new file mode 100644
index 0000000..7faedb8
--- /dev/null
+++ b/src/error_diag.h
@@ -0,0 +1,167 @@
+// Copyright 2008 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// error_diag.h: Ambiguous error diagnosis class
+
+#ifndef STRESSAPPTEST_ERROR_DIAG_H_
+#define STRESSAPPTEST_ERROR_DIAG_H_
+
+#include <pthread.h>
+#include <list>
+#include <map>
+#include <set>
+#include <string>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "sattypes.h"
+#include "os.h"
+
+class ErrorInstance;
+
+// This describes the components of the system.
+class DeviceTree {
+ public:
+  explicit DeviceTree(string name);
+  ~DeviceTree();
+
+  // Atomically find arbitrary device in subtree.
+  DeviceTree *FindInSubTree(string name);
+  // Find or add named device.
+  DeviceTree *FindOrAddDevice(string name);
+  // Atomically add sub device.
+  void InsertSubDevice(string name);
+  // Returns parent device.
+  DeviceTree *GetParent() { return parent_; }
+  // Pretty prints device tree.
+  void PrettyPrint(string spacer = " ");
+  // Atomically add error instance to device.
+  void AddErrorInstance(ErrorInstance *error_instance);
+  // Returns true of device is known to be bad.
+  bool KnownBad();
+  // Returns number of direct sub devices.
+  int NumDirectSubDevices() { return subdevices_.size(); }
+
+ private:
+  // Unlocked version of FindInSubTree.
+  DeviceTree *UnlockedFindInSubTree(string name);
+
+  std::map<string, DeviceTree*> subdevices_;    // Map of sub-devices.
+  std::list<ErrorInstance*> errors_;            // Log of errors.
+  DeviceTree *parent_;                          // Pointer to parent device.
+  string name_;                                 // Device name.
+  pthread_mutex_t device_tree_mutex_;           // Mutex protecting device tree.
+};
+
+
+// enum type for collected errors.
+enum SATErrorType {
+  SAT_ERROR_NONE = 0,
+  SAT_ERROR_ECC,
+  SAT_ERROR_MISCOMPARE,
+  SAT_ERROR_SECTOR_TAG,
+};
+
+// enum type for error severity.
+enum SATErrorSeverity {
+  SAT_ERROR_CORRECTABLE = 0,
+  SAT_ERROR_FATAL,
+};
+
+// This describes an error and it's likely causes.
+class ErrorInstance {
+ public:
+  ErrorInstance(): type_(SAT_ERROR_NONE), severity_(SAT_ERROR_CORRECTABLE) {}
+
+  SATErrorType type_;             // Type of error: ECC, miscompare, sector.
+  SATErrorSeverity severity_;     // Correctable, or fatal.
+  std::set<DeviceTree*> causes_;  // Devices that can cause this type of error.
+};
+
+// This describes ECC errors.
+class ECCErrorInstance: public ErrorInstance {
+ public:
+  ECCErrorInstance() { type_ = SAT_ERROR_ECC; }
+
+  uint64 addr_;               // Address where error occured.
+};
+
+// This describes miscompare errors.
+class MiscompareErrorInstance: public ErrorInstance {
+ public:
+  MiscompareErrorInstance() { type_ = SAT_ERROR_MISCOMPARE; }
+
+  uint64 addr_;               // Address where miscompare occured.
+};
+
+// This describes HDD miscompare errors.
+class HDDMiscompareErrorInstance: public MiscompareErrorInstance {
+ public:
+  uint64 addr2_;             // addr_ and addr2_ are src and dst memory addr.
+  int offset_;               // offset.
+  int block_;                // error block.
+};
+
+// This describes HDD miscompare errors.
+class HDDSectorTagErrorInstance: public ErrorInstance {
+ public:
+  HDDSectorTagErrorInstance() { type_ = SAT_ERROR_SECTOR_TAG; }
+
+  uint64 addr_;
+  uint64 addr2_;             // addr_ and addr2_ are src and dst memory addr.
+  int sector_;               // error sector.
+  int block_;                // error block.
+};
+
+// Generic error storage and sorting class.
+class ErrorDiag {
+ public:
+  ErrorDiag();
+  virtual ~ErrorDiag();
+
+  // Add info about a CECC.
+  virtual int AddCeccError(string dimm_string);
+
+  // Add info about a UECC.
+  virtual int AddUeccError(string dimm_string);
+
+  // Add info about a miscompare.
+  virtual int AddMiscompareError(string dimm_string, uint64 addr, int count);
+
+  // Add info about a miscompare from a drive.
+  virtual int AddHDDMiscompareError(string devicename, int block, int offset,
+                            void *src_addr, void *dst_addr);
+
+  // Add info about a sector tag miscompare from a drive.
+  virtual int AddHDDSectorTagError(string devicename, int block, int offset,
+                           int sector, void *src_addr, void *dst_addr);
+
+  // Set platform specific handle and initialize device tree.
+  bool set_os(OsLayer *os);
+
+ protected:
+  // Create and initialize system device tree.
+  virtual bool InitializeDeviceTree();
+
+  // Utility Function to translate a virtual address to DIMM number.
+  string AddressToDimmString(OsLayer *os, void *addr, int offset);
+
+  DeviceTree *system_tree_root_;  // System device tree.
+  OsLayer *os_;                   // Platform handle.
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ErrorDiag);
+};
+
+#endif  // STRESSAPPTEST_ERROR_DIAG_H_
diff --git a/src/finelock_queue.cc b/src/finelock_queue.cc
new file mode 100644
index 0000000..8d914b8
--- /dev/null
+++ b/src/finelock_queue.cc
@@ -0,0 +1,448 @@
+// Copyright 2007 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This is an interface to a simple thread safe container with fine-grain locks,
+// used to hold data blocks and patterns.
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "finelock_queue.h"
+#include "os.h"
+
+// Page entry queue implementation follows.
+// Push and Get functions are analogous to lock and unlock operations on a given
+// page entry, while preserving queue semantics.
+//
+// The actual 'queue' implementation is actually just an array. The entries are
+// never shuffled or re-ordered like that of a real queue. Instead, Get
+// functions return a random page entry of a given type and lock that particular
+// page entry until it is unlocked by corresponding Put functions.
+//
+// In this implementation, a free page is those page entries where pattern is
+// null (pe->pattern == 0)
+
+
+// Constructor: Allocates memory and initialize locks.
+FineLockPEQueue::FineLockPEQueue(
+                 uint64 queuesize, int64 pagesize) {
+  q_size_ = queuesize;
+  pages_ = new struct page_entry[q_size_];
+  pagelocks_ = new pthread_mutex_t[q_size_];
+  page_size_ = pagesize;
+
+  // What metric should we measure this run.
+  queue_metric_ = kTouch;
+
+  {  // Init all the page locks.
+    for (uint64 i = 0; i < q_size_; i++) {
+        pthread_mutex_init(&(pagelocks_[i]), NULL);
+        // Pages start out owned (locked) by Sat::InitializePages.
+        // A locked state indicates that the page state is unknown,
+        // and the lock should not be aquired. As InitializePages creates
+        // the page records, they will be inserted and unlocked, at which point
+        // they are ready to be aquired and filled by worker threads.
+        sat_assert(pthread_mutex_lock(&(pagelocks_[i])) == 0);
+    }
+  }
+
+  {  // Init the random number generator.
+    for (int i = 0; i < 4; i++) {
+      rand_seed_[i] = i + 0xbeef;
+      pthread_mutex_init(&(randlocks_[i]), NULL);
+    }
+  }
+
+  // Try to make a linear congruential generator with our queue size.
+  // We need this to deterministically search all the queue (being able to find
+  // a single available element is a design requirement), but we don't want to
+  // cause any page to be more likley chosen than another. The previous
+  // sequential retry heavily biased pages at the beginning of a bunch, or
+  // isolated pages surrounded by unqualified ones.
+  int64 length = queuesize;
+  int64 modlength = length;
+  int64 a;
+  int64 c;
+
+  if (length < 3) {
+    a = 1;
+    c = 1;
+  } else {
+    // Search for a nontrivial generator.
+    a = getA(length) % length;
+    // If this queue size doesn't have a nontrivial generator (where the
+    // multiplier is greater then one) we'll check increasing queue sizes,
+    // and discard out of bounds results.
+    while (a == 1) {
+      modlength++;
+      a = getA(modlength) % modlength;
+    }
+    c = getC(modlength);
+  }
+
+  // This is our final generator.
+  a_ = a;
+  c_ = c;
+  modlength_ = modlength;
+}
+
+// Part of building a linear congruential generator n1 = (a * n0 + c) % m
+// Get 'a', where a - 1 must be divisible by all prime
+// factors of 'm', our queue size.
+int64 FineLockPEQueue::getA(int64 m) {
+  int64 remaining = m;
+  int64 a = 1;
+  if ((((remaining / 4) * 4) == remaining)) {
+    a = 2;
+  }
+  // For each number, let's see if it's divisible,
+  // then divide it out.
+  for (int64 i = 2; i <= m; i++) {
+    if (((remaining / i) * i) == remaining) {
+      remaining /= i;
+      // Keep dividing it out until there's no more.
+      while (((remaining / i) * i) == remaining)
+        remaining /= i;
+      a *= i;
+    }
+  }
+
+  // Return 'a' as specified.
+  return (a + 1) % m;
+}
+
+
+// Part of building a linear congruential generator n1 = (a * n0 + c) % m
+// Get a prime number approx 3/4 the size of our queue.
+int64 FineLockPEQueue::getC(int64 m) {
+  // Start here at 3/4.
+  int64 start = (3 * m) / 4 + 1;
+  int64 possible_prime = start;
+  // Keep trying until we find a prime.
+  for (possible_prime = start; possible_prime > 1; possible_prime--) {
+    bool failed = false;
+    for (int64 i = 2; i < possible_prime; i++) {
+      if (((possible_prime / i) * i) == possible_prime) {
+        failed = true;
+        break;
+      }
+    }
+    if (!failed) {
+      return possible_prime;
+    }
+  }
+  // One is prime enough.
+  return 1;
+}
+
+// Destructor: Clean-up allocated memory and destroy pthread locks.
+FineLockPEQueue::~FineLockPEQueue() {
+  uint64 i;
+  for (i = 0; i < q_size_; i++)
+    pthread_mutex_destroy(&(pagelocks_[i]));
+  delete[] pagelocks_;
+  delete[] pages_;
+  for (i = 0; i < 4; i++) {
+    pthread_mutex_destroy(&(randlocks_[i]));
+  }
+}
+
+
+bool FineLockPEQueue::QueueAnalysis() {
+  const char *measurement = "Error";
+  uint64 buckets[32];
+
+  if (queue_metric_ == kTries)
+    measurement = "Failed retrievals";
+  else if (queue_metric_ == kTouch)
+    measurement = "Reads per page";
+
+  // Buckets for each log2 access counts.
+  for (int b = 0; b < 32; b++) {
+    buckets[b] = 0;
+  }
+
+  // Bucketize the page counts by highest bit set.
+  for (uint64 i = 0; i < q_size_; i++) {
+    uint32 readcount = pages_[i].touch;
+    int b = 0;
+    for (b = 0; b < 31; b++) {
+      if (readcount < (1u << b))
+        break;
+    }
+
+    buckets[b]++;
+  }
+
+  logprintf(12, "Log:  %s histogram\n", measurement);
+  for (int b = 0; b < 32; b++) {
+    if (buckets[b])
+      logprintf(12, "Log:  %12d - %12d: %12d\n",
+          ((1 << b) >> 1), 1 << b, buckets[b]);
+  }
+
+  return true;
+}
+
+namespace {
+// Callback mechanism for exporting last action.
+OsLayer *g_os;
+FineLockPEQueue *g_fpqueue = 0;
+
+// Global callback to hook into Os object.
+bool err_log_callback(uint64 paddr, string *buf) {
+  if (g_fpqueue) {
+    return g_fpqueue->ErrorLogCallback(paddr, buf);
+  }
+  return false;
+}
+}
+
+// Setup global state for exporting callback.
+void FineLockPEQueue::set_os(OsLayer *os) {
+  g_os = os;
+  g_fpqueue = this;
+}
+
+OsLayer::ErrCallback FineLockPEQueue::get_err_log_callback() {
+  return err_log_callback;
+}
+
+// This call is used to export last transaction info on a particular physical
+// address.
+bool FineLockPEQueue::ErrorLogCallback(uint64 paddr, string *message) {
+  struct page_entry pe;
+  OsLayer *os = g_os;
+  sat_assert(g_os);
+  char buf[256];
+
+  // Find the page of this paddr.
+  int gotpage = GetPageFromPhysical(paddr, &pe);
+  if (!gotpage) {
+    return false;
+  }
+
+  // Find offset into the page.
+  uint64 addr_diff = paddr - pe.paddr;
+
+  // Find vaddr of this paddr. Make sure it matches,
+  // as sometimes virtual memory is not contiguous.
+  char *vaddr =
+    reinterpret_cast<char*>(os->PrepareTestMem(pe.offset, page_size_));
+  uint64 new_paddr = os->VirtualToPhysical(vaddr + addr_diff);
+  os->ReleaseTestMem(vaddr, pe.offset, page_size_);
+
+  // Is the physical address at this page offset the same as
+  // the physical address we were given?
+  if (new_paddr != paddr) {
+    return false;
+  }
+
+  // Print all the info associated with this page.
+  message->assign(" (Last Transaction:");
+
+  if (pe.lastpattern) {
+    int offset = addr_diff / 8;
+    datacast_t data;
+
+    data.l32.l = pe.lastpattern->pattern(offset << 1);
+    data.l32.h = pe.lastpattern->pattern((offset << 1) + 1);
+
+    snprintf(buf, sizeof(buf), " %s data=%#016llx",
+                  pe.lastpattern->name(), data.l64);
+    message->append(buf);
+  }
+  snprintf(buf, sizeof(buf), " tsc=%#llx)", pe.ts);
+  message->append(buf);
+  return true;
+}
+
+bool FineLockPEQueue::GetPageFromPhysical(uint64 paddr,
+                                          struct page_entry *pe) {
+  // Traverse through array until finding a page
+  // that contains the address we want..
+  for (uint64 i = 0; i < q_size_; i++) {
+    uint64 page_addr = pages_[i].paddr;
+    // This assumes linear vaddr.
+    if ((page_addr <= paddr) && (page_addr + page_size_ > paddr)) {
+      *pe = pages_[i];
+      return true;
+    }
+  }
+  return false;
+}
+
+
+// Get a random number from the slot we locked.
+uint64 FineLockPEQueue::GetRandom64FromSlot(int slot) {
+  // 64 bit LCG numbers suggested on the internets by
+  // http://nuclear.llnl.gov/CNP/rng/rngman/node4.html and others.
+  uint64 result = 2862933555777941757ULL * rand_seed_[slot] + 3037000493ULL;
+  rand_seed_[slot] = result;
+  return result;
+}
+
+// Get a random number, we have 4 generators to choose from so hopefully we
+// won't be blocking on this.
+uint64 FineLockPEQueue::GetRandom64() {
+  // Try each available slot.
+  for (int i = 0; i < 4; i++) {
+    if (pthread_mutex_trylock(&(randlocks_[i])) == 0) {
+      uint64 result = GetRandom64FromSlot(i);
+      pthread_mutex_unlock(&(randlocks_[i]));
+      return result;
+    }
+  }
+  // Forget it, just wait.
+  int i = 0;
+  if (pthread_mutex_lock(&(randlocks_[i])) == 0) {
+    uint64 result = GetRandom64FromSlot(i);
+    pthread_mutex_unlock(&(randlocks_[i]));
+    return result;
+  }
+
+  logprintf(0, "Process Error: Could not acquire random lock.\n");
+  sat_assert(0);
+  return 0;
+}
+
+
+// Helper function to get a random page entry with given predicate,
+// ie, page_is_valid() or page_is_empty() as defined in finelock_queue.h.
+//
+// Setting tag to a value other than kDontCareTag (-1)
+// indicates that we need a tag match, otherwise any tag will do.
+//
+// Returns true on success, false on failure.
+bool FineLockPEQueue::GetRandomWithPredicateTag(struct page_entry *pe,
+                      bool (*pred_func)(struct page_entry*),
+                      int32 tag) {
+  if (!pe || !q_size_)
+    return false;
+
+  // Randomly index into page entry array.
+  uint64 first_try = GetRandom64() % q_size_;
+  uint64 next_try = 1;
+
+  // Traverse through array until finding a page meeting given predicate.
+  for (uint64 i = 0; i < q_size_; i++) {
+    uint64 index = (next_try + first_try) % q_size_;
+    // Go through the loop linear conguentially. We are offsetting by
+    // 'first_try' so this path will be a different sequence for every
+    // initioal value chosen.
+    next_try = (a_ * next_try + c_) % (modlength_);
+    while (next_try >= q_size_) {
+      // If we have chosen a modlength greater than the queue size,
+      // discard out of bounds results.
+      next_try = (a_ * next_try + c_) % (modlength_);
+    }
+
+    // If page does not meet predicate, don't trylock (expensive).
+    if (!(pred_func)(&pages_[index]))
+      continue;
+
+    // If page does not meet tag predicate, don't trylock (expensive).
+    if ((tag != kDontCareTag) && !(pages_[index].tag & tag))
+      continue;
+
+    if (pthread_mutex_trylock(&(pagelocks_[index])) == 0) {
+      // If page property (valid/empty) changes before successfully locking,
+      // release page and move on.
+      if (!(pred_func)(&pages_[index])) {
+        pthread_mutex_unlock(&(pagelocks_[index]));
+        continue;
+      } else {
+        // A page entry with given predicate is locked, returns success.
+        *pe = pages_[index];
+
+        // Add metrics as necessary.
+        if (pred_func == page_is_valid) {
+          // Measure time to fetch valid page.
+          if (queue_metric_ == kTries)
+            pe->touch = i;
+          // Measure number of times each page is read.
+          if (queue_metric_ == kTouch)
+            pe->touch++;
+        }
+
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+// Without tag hint.
+bool FineLockPEQueue::GetRandomWithPredicate(struct page_entry *pe,
+                      bool (*pred_func)(struct page_entry*)) {
+  return GetRandomWithPredicateTag(pe, pred_func, kDontCareTag);
+}
+
+
+// GetValid() randomly finds a valid page, locks it and returns page entry by
+// pointer.
+//
+// Returns true on success, false on failure.
+bool FineLockPEQueue::GetValid(struct page_entry *pe) {
+  return GetRandomWithPredicate(pe, page_is_valid);
+}
+
+bool FineLockPEQueue::GetValid(struct page_entry *pe, int32 mask) {
+  return GetRandomWithPredicateTag(pe, page_is_valid, mask);
+}
+
+// GetEmpty() randomly finds an empty page, locks it and returns page entry by
+// pointer.
+//
+// Returns true on success, false on failure.
+bool FineLockPEQueue::GetEmpty(struct page_entry *pe, int32 mask) {
+  return GetRandomWithPredicateTag(pe, page_is_empty, mask);
+}
+bool FineLockPEQueue::GetEmpty(struct page_entry *pe) {
+  return GetRandomWithPredicate(pe, page_is_empty);
+}
+
+// PutEmpty puts an empty page back into the queue, making it available by
+// releasing the per-page-entry lock.
+//
+// Returns true on success, false on failure.
+bool FineLockPEQueue::PutEmpty(struct page_entry *pe) {
+  if (!pe || !q_size_)
+    return false;
+
+  int64 index = pe->offset / page_size_;
+  if (!valid_index(index))
+    return false;
+
+  pages_[index] = *pe;
+  // Enforce that page entry is indeed empty.
+  pages_[index].pattern = 0;
+  return (pthread_mutex_unlock(&(pagelocks_[index])) == 0);
+}
+
+// PutValid puts a valid page back into the queue, making it available by
+// releasing the per-page-entry lock.
+//
+// Returns true on success, false on failure.
+bool FineLockPEQueue::PutValid(struct page_entry *pe) {
+  if (!pe || !page_is_valid(pe) || !q_size_)
+    return false;
+
+  int64 index = pe->offset / page_size_;
+  if (!valid_index(index))
+    return false;
+
+  pages_[index] = *pe;
+  return (pthread_mutex_unlock(&(pagelocks_[index])) == 0);
+}
diff --git a/src/finelock_queue.h b/src/finelock_queue.h
new file mode 100644
index 0000000..2de5a46
--- /dev/null
+++ b/src/finelock_queue.h
@@ -0,0 +1,118 @@
+// Copyright 2007 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This page entry queue implementation with fine grain locks aim to ease
+// lock contention over previous queue implementation (with one lock protecting
+// the entire queue).
+
+#ifndef STRESSAPPTEST_FINELOCK_QUEUE_H_
+#define STRESSAPPTEST_FINELOCK_QUEUE_H_
+
+#include <string>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "sattypes.h"
+#include "pattern.h"
+#include "queue.h"     // Using page_entry struct.
+#include "os.h"
+
+// This is a threadsafe randomized queue of pages with per-page entry lock
+// for worker threads to use.
+class FineLockPEQueue {
+ public:
+  FineLockPEQueue(uint64 queuesize, int64 pagesize);
+  ~FineLockPEQueue();
+
+  // Put and get functions for page entries.
+  bool GetEmpty(struct page_entry *pe);
+  bool GetValid(struct page_entry *pe);
+  bool PutEmpty(struct page_entry *pe);
+  bool PutValid(struct page_entry *pe);
+
+  // Put and get functions for page entries, selecting on tags.
+  bool GetEmpty(struct page_entry *pe, int32 tag);
+  bool GetValid(struct page_entry *pe, int32 tag);
+
+  bool QueueAnalysis();
+  bool GetPageFromPhysical(uint64 paddr, struct page_entry *pe);
+  void set_os(OsLayer *os);
+  OsLayer::ErrCallback get_err_log_callback();
+  bool ErrorLogCallback(uint64 paddr, string *buf);
+
+ private:
+  // Not that much blocking random number generator.
+  uint64 GetRandom64();
+  uint64 GetRandom64FromSlot(int slot);
+
+  // Helper function to check index range, returns true if index is valid.
+  bool valid_index(int64 index) {
+    return index >= 0 && static_cast<uint64>(index) < q_size_;
+  }
+
+  // Returns true if page entry is valid, false otherwise.
+  static bool page_is_valid(struct page_entry *pe) {
+    return pe->pattern != NULL;
+  }
+  // Returns true if page entry is empty, false otherwise.
+  static bool page_is_empty(struct page_entry *pe) {
+    return pe->pattern == NULL;
+  }
+
+  // Helper function to get a random page entry with given predicate,
+  // ie, page_is_valid() or page_is_empty() as defined above.
+  bool GetRandomWithPredicate(struct page_entry *pe,
+                              bool (*pred_func)(struct page_entry*));
+
+  // Helper function to get a random page entry with given predicate,
+  // ie, page_is_valid() or page_is_empty() as defined above.
+  bool GetRandomWithPredicateTag(struct page_entry *pe,
+                                 bool (*pred_func)(struct page_entry*),
+                                 int32 tag);
+
+  // Used to make a linear congruential path through the queue.
+  int64 getA(int64 m);
+  int64 getC(int64 m);
+
+  pthread_mutex_t *pagelocks_;  // Per-page-entry locks.
+  struct page_entry *pages_;     // Where page entries are held.
+  uint64 q_size_;                // Size of the queue.
+  int64 page_size_;              // For calculating array index from offset.
+
+  enum {
+    kTries = 1,     // Measure the number of attempts in the queue
+                    // before getting a matching page.
+    kTouch = 2 }    // Measure the number of touches on each page.
+    queue_metric_;  // What to measure in the 'tries' field.
+
+  // Progress pseudorandomly through the queue. It's required that we can find
+  // every value in the list, but progressing through the same order each time
+  // causes bunching of pages, leading to long seach times for the correct
+  // type of pages.
+  int64 a_;                      // 'a' multiplicative value for progressing
+                                 // linear congruentially through the list.
+  int64 c_;                      // 'c' additive value for prgressing randomly
+                                 // through the list.
+  int64 modlength_;              // 'm' mod value for linear congruential
+                                 // generator. Used when q_size_ doesn't
+                                 // generate a good progression through the
+                                 // list.
+
+  uint64 rand_seed_[4];          // Random number state for 4 generators.
+  pthread_mutex_t randlocks_[4];  // Per-random-generator locks.
+
+  DISALLOW_COPY_AND_ASSIGN(FineLockPEQueue);
+};
+
+#endif  // STRESSAPPTEST_FINELOCK_QUEUE_H_
diff --git a/src/logger.cc b/src/logger.cc
new file mode 100644
index 0000000..e4ecb03
--- /dev/null
+++ b/src/logger.cc
@@ -0,0 +1,152 @@
+// Copyright 2009 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "logger.h"
+
+#include <pthread.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "sattypes.h"
+
+
+Logger *Logger::GlobalLogger() {
+  static Logger logger;
+  return &logger;
+}
+
+void Logger::VLogF(int priority, const char *format, va_list args) {
+  if (priority > verbosity_) {
+    return;
+  }
+  char buffer[4096];
+  int length = vsnprintf(buffer, sizeof buffer, format, args);
+  if (static_cast<size_t>(length) >= sizeof buffer) {
+    length = sizeof buffer;
+    buffer[sizeof buffer - 1] = '\n';
+  }
+  QueueLogLine(new string(buffer, length));
+}
+
+void Logger::StartThread() {
+  LOGGER_ASSERT(!thread_running_);
+  thread_running_ = true;
+  LOGGER_ASSERT(0 == pthread_create(&thread_, NULL, &StartRoutine, this));
+}
+
+void Logger::StopThread() {
+  LOGGER_ASSERT(thread_running_);
+  thread_running_ = false;
+  LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
+  bool need_cond_signal = queued_lines_.empty();
+  queued_lines_.push_back(NULL);
+  LOGGER_ASSERT(0 == pthread_mutex_unlock(&queued_lines_mutex_));
+  if (need_cond_signal) {
+    LOGGER_ASSERT(0 == pthread_cond_signal(&queued_lines_cond_));
+  }
+  LOGGER_ASSERT(0 == pthread_join(thread_, NULL));
+}
+
+Logger::Logger() : verbosity_(20), log_fd_(-1), thread_running_(false) {
+  LOGGER_ASSERT(0 == pthread_mutex_init(&queued_lines_mutex_, NULL));
+  LOGGER_ASSERT(0 == pthread_cond_init(&queued_lines_cond_, NULL));
+  LOGGER_ASSERT(0 == pthread_cond_init(&full_queue_cond_, NULL));
+}
+
+Logger::~Logger() {
+  LOGGER_ASSERT(0 == pthread_mutex_destroy(&queued_lines_mutex_));
+  LOGGER_ASSERT(0 == pthread_cond_destroy(&queued_lines_cond_));
+  LOGGER_ASSERT(0 == pthread_cond_destroy(&full_queue_cond_));
+}
+
+void Logger::QueueLogLine(string *line) {
+  LOGGER_ASSERT(line != NULL);
+  LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
+  if (thread_running_) {
+    if (queued_lines_.size() >= kMaxQueueSize) {
+      LOGGER_ASSERT(0 == pthread_cond_wait(&full_queue_cond_,
+                                           &queued_lines_mutex_));
+    }
+    if (queued_lines_.empty()) {
+      LOGGER_ASSERT(0 == pthread_cond_signal(&queued_lines_cond_));
+    }
+    queued_lines_.push_back(line);
+  } else {
+    WriteAndDeleteLogLine(line);
+  }
+  LOGGER_ASSERT(0 == pthread_mutex_unlock(&queued_lines_mutex_));
+}
+
+namespace {
+void WriteToFile(const string& line, int fd) {
+  LOGGER_ASSERT(write(fd, line.data(), line.size()) ==
+                static_cast<ssize_t>(line.size()));
+}
+}
+
+void Logger::WriteAndDeleteLogLine(string *line) {
+  LOGGER_ASSERT(line != NULL);
+  if (log_fd_ >= 0) {
+    WriteToFile(*line, log_fd_);
+  }
+  WriteToFile(*line, 1);
+  delete line;
+}
+
+void *Logger::StartRoutine(void *ptr) {
+  Logger *self = static_cast<Logger*>(ptr);
+  self->ThreadMain();
+  return NULL;
+}
+
+void Logger::ThreadMain() {
+  vector<string*> local_queue;
+  LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
+
+  for (;;) {
+    if (queued_lines_.empty()) {
+      LOGGER_ASSERT(0 == pthread_cond_wait(&queued_lines_cond_,
+                                           &queued_lines_mutex_));
+      continue;
+    }
+
+    // We move the log lines into a local queue so we can release the lock
+    // while writing them to disk, preventing other threads from blocking on
+    // our writes.
+    local_queue.swap(queued_lines_);
+    if (local_queue.size() >= kMaxQueueSize) {
+      LOGGER_ASSERT(0 == pthread_cond_broadcast(&full_queue_cond_));
+    }
+
+    // Unlock while we process our local queue.
+    LOGGER_ASSERT(0 == pthread_mutex_unlock(&queued_lines_mutex_));
+    for (vector<string*>::const_iterator it = local_queue.begin();
+         it != local_queue.end(); ++it) {
+      if (*it == NULL) {
+        // NULL is guaranteed to be at the end.
+        return;
+      }
+      WriteAndDeleteLogLine(*it);
+    }
+    local_queue.clear();
+    // We must hold the lock at the start of each iteration of this for loop.
+    LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
+  }
+}
diff --git a/src/logger.h b/src/logger.h
new file mode 100644
index 0000000..1d70107
--- /dev/null
+++ b/src/logger.h
@@ -0,0 +1,142 @@
+// Copyright 2009 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef STRESSAPPTEST_LOGGER_H_
+#define STRESSAPPTEST_LOGGER_H_
+
+#include <pthread.h>
+#include <stdarg.h>
+
+#include <string>
+#include <vector>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "sattypes.h"
+
+// Attempts to log additional lines will block when the queue reaches this size.
+// Due to how the logging thread works, up to twice this many log lines may be
+// outstanding at any point.
+static const size_t kMaxQueueSize = 250;
+
+
+// This is only for use by the Logger class, do not use it elsewhere!
+//
+// All Logger assertions should use this macro instead of sat_assert().
+//
+// This is like sat_assert() from sattypes.h, but whereas sat_assert() tries to
+// log the assertion after printing it to stderr, this only prints it to stderr.
+// Logging from within the wrong part of the logger would trigger a deadlock,
+// and even in places where it wouldn't there's a very good chance that the
+// logger is in no condition to handle new log lines.
+#define LOGGER_ASSERT(x) \
+{\
+  if (!(x)) {\
+    fprintf(stderr, "Assertion failed at %s:%d\n", __FILE__, __LINE__);\
+    exit(1);\
+  }\
+}
+
+
+// This class handles logging in SAT.  It is a singleton accessed via
+// GlobalLogger().
+//
+// By default log lines are written in the calling thread.  Call StartThread()
+// to launch a dedicated thread for the writes.
+class Logger {
+ public:
+  // Returns a pointer to the single global Logger instance.  Will not return
+  // NULL.
+  static Logger *GlobalLogger();
+
+  // Lines with a priority numerically greater than this will not be logged.
+  // May not be called while multiple threads are running.
+  void SetVerbosity(int verbosity) {
+    verbosity_ = verbosity;
+  }
+
+  // Sets a file to log to, in addition to stdout.  May not be called while
+  // multiple threads are running.
+  //
+  // Args:
+  //   log_fd: The file descriptor to write to.  Will not be closed by this
+  //           object.
+  void SetLogFd(int log_fd) {
+    LOGGER_ASSERT(log_fd >= 0);
+    log_fd_ = log_fd;
+  }
+
+  // Set output to be written to stdout only.  This is the default mode.  May
+  // not be called while multiple threads are running.
+  void SetStdoutOnly() {
+    log_fd_ = -1;
+  }
+
+  // Logs a line, with a vprintf(3)-like interface.  This will block on writing
+  // the line to stdout/disk iff the dedicated logging thread is not running.
+  // This will block on adding the line to the queue if doing so would exceed
+  // kMaxQueueSize.
+  //
+  // Args:
+  //   priority: If this is numerically greater than the verbosity, the line
+  //             will not be logged.
+  //   format: see vprintf(3)
+  //   args: see vprintf(3)
+  void VLogF(int priority, const char *format, va_list args);
+
+  // Starts the dedicated logging thread.  May not be called while multiple
+  // threads are already running.
+  void StartThread();
+
+  // Stops the dedicated logging thread.  May only be called when the logging
+  // thread is the only other thread running.  Any queued lines will be logged
+  // before this returns.  Waits for the thread to finish before returning.
+  void StopThread();
+
+ private:
+  Logger();
+
+  ~Logger();
+
+  // Args:
+  //   line: Must be non-NULL.  This function takes ownership of it.
+  void QueueLogLine(string *line);
+
+  // Args:
+  //   line: Must be non-NULL.  This function takes ownership of it.
+  void WriteAndDeleteLogLine(string *line);
+
+  // Callback for pthread_create(3).
+  static void *StartRoutine(void *ptr);
+
+  // Processes the log queue.
+  void ThreadMain();
+
+  pthread_t thread_;
+  int verbosity_;
+  int log_fd_;
+  bool thread_running_;
+  vector<string*> queued_lines_;
+  // This doubles as a mutex for log_fd_ when the logging thread is not running.
+  pthread_mutex_t queued_lines_mutex_;
+  // Lets the logging thread know that the queue is no longer empty.
+  pthread_cond_t queued_lines_cond_;
+  // Lets the threads blocked on the queue having reached kMaxQueueSize know
+  // that the queue has been emptied.
+  pthread_cond_t full_queue_cond_;
+
+  DISALLOW_COPY_AND_ASSIGN(Logger);
+};
+
+#endif  // STRESSAPPTEST_LOGGER_H_
diff --git a/src/main.cc b/src/main.cc
new file mode 100644
index 0000000..04cd536
--- /dev/null
+++ b/src/main.cc
@@ -0,0 +1,56 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// sat.cc : a stress test for stressful testing
+
+#include "sattypes.h"
+#include "sat.h"
+
+int main(int argc, char **argv) {
+  Sat *sat = SatFactory();
+  if (sat == NULL) {
+    logprintf(0, "Process Error: failed to allocate Sat object\n");
+    return 255;
+  }
+
+  if (!sat->ParseArgs(argc, argv)) {
+    logprintf(0, "Process Error: Sat::ParseArgs() failed\n");
+    sat->bad_status();
+  } else if (!sat->Initialize()) {
+    logprintf(0, "Process Error: Sat::Initialize() failed\n");
+    sat->bad_status();
+  } else if (!sat->Run()) {
+    logprintf(0, "Process Error: Sat::Run() failed\n");
+    sat->bad_status();
+  }
+  sat->PrintResults();
+  if (!sat->Cleanup()) {
+    logprintf(0, "Process Error: Sat::Cleanup() failed\n");
+    sat->bad_status();
+  }
+
+  int retval;
+  if (sat->status() != 0) {
+    logprintf(0, "Process Error: Fatal issue encountered. See above logs for "
+              "details.\n");
+    retval = 1;
+  } else if (sat->errors() != 0) {
+    retval = 1;
+  } else {
+    retval = 0;
+  }
+
+  delete sat;
+  return retval;
+}
diff --git a/src/os.cc b/src/os.cc
new file mode 100644
index 0000000..1340d6b
--- /dev/null
+++ b/src/os.cc
@@ -0,0 +1,849 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+// Author: nsanders, menderico
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// os.cc : os and machine specific implementation
+// This file includes an abstracted interface
+// for linux-distro specific and HW specific
+// interfaces.
+
+#include "os.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/types.h>
+#include <malloc.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <unistd.h>
+
+#ifndef SHM_HUGETLB
+#define SHM_HUGETLB      04000  // remove when glibc defines it
+#endif
+
+#include <string>
+#include <list>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "sattypes.h"
+#include "error_diag.h"
+
+// OsLayer initialization.
+OsLayer::OsLayer() {
+  testmem_ = 0;
+  testmemsize_ = 0;
+  totalmemsize_ = 0;
+  min_hugepages_bytes_ = 0;
+  normal_mem_ = true;
+  use_hugepages_ = false;
+  use_posix_shm_ = false;
+  dynamic_mapped_shmem_ = false;
+  shmid_ = 0;
+
+  time_initialized_ = 0;
+
+  regionsize_ = 0;
+  regioncount_ = 1;
+  num_cpus_ = 0;
+  num_nodes_ = 0;
+  num_cpus_per_node_ = 0;
+  error_diagnoser_ = 0;
+  err_log_callback_ = 0;
+  error_injection_ = false;
+
+  void *pvoid = 0;
+  address_mode_ = sizeof(pvoid) * 8;
+
+  has_clflush_ = false;
+  has_sse2_ = false;
+}
+
+// OsLayer cleanup.
+OsLayer::~OsLayer() {
+  if (error_diagnoser_)
+    delete error_diagnoser_;
+}
+
+// OsLayer initialization.
+bool OsLayer::Initialize() {
+  time_initialized_ = time(NULL);
+  // Detect asm support.
+  GetFeatures();
+
+  if (num_cpus_ == 0) {
+    num_nodes_ = 1;
+    num_cpus_ = sysconf(_SC_NPROCESSORS_ONLN);
+    num_cpus_per_node_ = num_cpus_ / num_nodes_;
+  }
+  logprintf(5, "Log: %d nodes, %d cpus.\n", num_nodes_, num_cpus_);
+  sat_assert(CPU_SETSIZE >= num_cpus_);
+  cpu_sets_.resize(num_nodes_);
+  cpu_sets_valid_.resize(num_nodes_);
+  // Create error diagnoser.
+  error_diagnoser_ = new ErrorDiag();
+  if (!error_diagnoser_->set_os(this))
+    return false;
+  return true;
+}
+
+// Machine type detected. Can we implement all these functions correctly?
+bool OsLayer::IsSupported() {
+  if (kOpenSource) {
+    // There are no explicitly supported systems in open source version.
+    return true;
+  }
+
+  // This is the default empty implementation.
+  // SAT won't report full error information.
+  return false;
+}
+
+int OsLayer::AddressMode() {
+  // Detect 32/64 bit binary.
+  void *pvoid = 0;
+  return sizeof(pvoid) * 8;
+}
+
+// Translates user virtual to physical address.
+uint64 OsLayer::VirtualToPhysical(void *vaddr) {
+  // Needs platform specific implementation.
+  return 0;
+}
+
+// Returns the HD device that contains this file.
+string OsLayer::FindFileDevice(string filename) {
+  return "hdUnknown";
+}
+
+// Returns a list of locations corresponding to HD devices.
+list<string> OsLayer::FindFileDevices() {
+  // No autodetection on unknown systems.
+  list<string> locations;
+  return locations;
+}
+
+
+// Get HW core features from cpuid instruction.
+void OsLayer::GetFeatures() {
+#if defined(STRESSAPPTEST_CPU_X86_64) || defined(STRESSAPPTEST_CPU_I686)
+  // CPUID features documented at:
+  // http://www.sandpile.org/ia32/cpuid.htm
+  int ax, bx, cx, dx;
+  __asm__ __volatile__ (
+      "cpuid": "=a" (ax), "=b" (bx), "=c" (cx), "=d" (dx) : "a" (1));
+  has_clflush_ = (dx >> 19) & 1;
+  has_sse2_ = (dx >> 26) & 1;
+
+  logprintf(9, "Log: has clflush: %s, has sse2: %s\n",
+            has_clflush_ ? "true" : "false",
+            has_sse2_ ? "true" : "false");
+#elif defined(STRESSAPPTEST_CPU_PPC)
+  // All PPC implementations have cache flush instructions.
+  has_clflush_ = true;
+#elif defined(STRESSAPPTEST_CPU_ARMV7A)
+#warning "Unsupported CPU type ARMV7A: unable to determine feature set."
+#else
+#warning "Unsupported CPU type: unable to determine feature set."
+#endif
+}
+
+
+// We need to flush the cacheline here.
+void OsLayer::Flush(void *vaddr) {
+  // Use the generic flush. This function is just so we can override
+  // this if we are so inclined.
+  if (has_clflush_)
+    FastFlush(vaddr);
+}
+
+
+// Run C or ASM copy as appropriate..
+bool OsLayer::AdlerMemcpyWarm(uint64 *dstmem, uint64 *srcmem,
+                              unsigned int size_in_bytes,
+                              AdlerChecksum *checksum) {
+  if (has_sse2_) {
+    return AdlerMemcpyAsm(dstmem, srcmem, size_in_bytes, checksum);
+  } else {
+    return AdlerMemcpyWarmC(dstmem, srcmem, size_in_bytes, checksum);
+  }
+}
+
+
+// Translate user virtual to physical address.
+int OsLayer::FindDimm(uint64 addr, char *buf, int len) {
+  char tmpbuf[256];
+  snprintf(tmpbuf, sizeof(tmpbuf), "DIMM Unknown");
+  snprintf(buf, len, "%s", tmpbuf);
+  return 0;
+}
+
+
+// Classifies addresses according to "regions"
+// This isn't really implemented meaningfully here..
+int32 OsLayer::FindRegion(uint64 addr) {
+  static bool warned = false;
+
+  if (regionsize_ == 0) {
+    regionsize_ = totalmemsize_ / 8;
+    if (regionsize_ < 512 * kMegabyte)
+      regionsize_ = 512 * kMegabyte;
+    regioncount_ = totalmemsize_ / regionsize_;
+    if (regioncount_ < 1) regioncount_ = 1;
+  }
+
+  int32 region_num = addr / regionsize_;
+  if (region_num >= regioncount_) {
+    if (!warned) {
+        logprintf(0, "Log: region number %d exceeds region count %d\n",
+                  region_num, regioncount_);
+        warned = true;
+    }
+    region_num = region_num % regioncount_;
+  }
+  return region_num;
+}
+
+// Report which cores are associated with a given region.
+cpu_set_t *OsLayer::FindCoreMask(int32 region) {
+  sat_assert(region >= 0);
+  region %= num_nodes_;
+  if (!cpu_sets_valid_[region]) {
+    CPU_ZERO(&cpu_sets_[region]);
+    for (int i = 0; i < num_cpus_per_node_; ++i) {
+      CPU_SET(i + region * num_cpus_per_node_, &cpu_sets_[region]);
+    }
+    cpu_sets_valid_[region] = true;
+    logprintf(5, "Log: Region %d mask 0x%s\n",
+                 region, FindCoreMaskFormat(region).c_str());
+  }
+  return &cpu_sets_[region];
+}
+
+// Return cores associated with a given region in hex string.
+string OsLayer::FindCoreMaskFormat(int32 region) {
+  cpu_set_t* mask = FindCoreMask(region);
+  string format = cpuset_format(mask);
+  if (format.size() < 8)
+    format = string(8 - format.size(), '0') + format;
+  return format;
+}
+
+// Report an error in an easily parseable way.
+bool OsLayer::ErrorReport(const char *part, const char *symptom, int count) {
+  time_t now = time(NULL);
+  int ttf = now - time_initialized_;
+  logprintf(0, "Report Error: %s : %s : %d : %ds\n", symptom, part, count, ttf);
+  return true;
+}
+
+// Read the number of hugepages out of the kernel interface in proc.
+int64 OsLayer::FindHugePages() {
+  char buf[65] = "0";
+
+  // This is a kernel interface to query the numebr of hugepages
+  // available in the system.
+  static const char *hugepages_info_file = "/proc/sys/vm/nr_hugepages";
+  int hpfile = open(hugepages_info_file, O_RDONLY);
+
+  ssize_t bytes_read = read(hpfile, buf, 64);
+  close(hpfile);
+
+  if (bytes_read <= 0) {
+    logprintf(12, "Log: /proc/sys/vm/nr_hugepages "
+                  "read did not provide data\n");
+    return 0;
+  }
+
+  if (bytes_read == 64) {
+    logprintf(0, "Process Error: /proc/sys/vm/nr_hugepages "
+                 "is surprisingly large\n");
+    return 0;
+  }
+
+  // Add a null termintation to be string safe.
+  buf[bytes_read] = '\0';
+  // Read the page count.
+  int64 pages = strtoull(buf, NULL, 10);  // NOLINT
+
+  return pages;
+}
+
+int64 OsLayer::FindFreeMemSize() {
+  int64 size = 0;
+  int64 minsize = 0;
+  if (totalmemsize_ > 0)
+    return totalmemsize_;
+
+  int64 pages = sysconf(_SC_PHYS_PAGES);
+  int64 avpages = sysconf(_SC_AVPHYS_PAGES);
+  int64 pagesize = sysconf(_SC_PAGESIZE);
+  int64 physsize = pages * pagesize;
+  int64 avphyssize = avpages * pagesize;
+
+  // Assume 2MB hugepages.
+  int64 hugepagesize = FindHugePages() * 2 * kMegabyte;
+
+  if ((pages == -1) || (pagesize == -1)) {
+    logprintf(0, "Process Error: sysconf could not determine memory size.\n");
+    return 0;
+  }
+
+  // We want to leave enough stuff for things to run.
+  // If the user specified a minimum amount of memory to expect, require that.
+  // Otherwise, if more than 2GB is present, leave 192M + 5% for other stuff.
+  // If less than 2GB is present use 85% of what's available.
+  // These are fairly arbitrary numbers that seem to work OK.
+  //
+  // TODO(nsanders): is there a more correct way to determine target
+  // memory size?
+  if (hugepagesize > 0 && min_hugepages_bytes_ > 0) {
+    minsize = min_hugepages_bytes_;
+  } else if (physsize < 2048LL * kMegabyte) {
+    minsize = ((pages * 85) / 100) * pagesize;
+  } else {
+    minsize = ((pages * 95) / 100) * pagesize - (192 * kMegabyte);
+  }
+
+  // Use hugepage sizing if available.
+  if (hugepagesize > 0) {
+    if (hugepagesize < minsize) {
+      logprintf(0, "Procedural Error: Not enough hugepages. "
+                   "%lldMB available < %lldMB required.\n",
+                hugepagesize / kMegabyte,
+                minsize / kMegabyte);
+      // Require the calculated minimum amount of memory.
+      size = minsize;
+    } else {
+      // Require that we get all hugepages.
+      size = hugepagesize;
+    }
+  } else {
+    // Require the calculated minimum amount of memory.
+    size = minsize;
+  }
+
+  logprintf(5, "Log: Total %lld MB. Free %lld MB. Hugepages %lld MB. "
+               "Targeting %lld MB (%lld%%)\n",
+            physsize / kMegabyte,
+            avphyssize / kMegabyte,
+            hugepagesize / kMegabyte,
+            size / kMegabyte,
+            size * 100 / physsize);
+
+  totalmemsize_ = size;
+  return size;
+}
+
+// Allocates all memory available.
+int64 OsLayer::AllocateAllMem() {
+  int64 length = FindFreeMemSize();
+  bool retval = AllocateTestMem(length, 0);
+  if (retval)
+    return length;
+  else
+    return 0;
+}
+
+// Allocate the target memory. This may be from malloc, hugepage pool
+// or other platform specific sources.
+bool OsLayer::AllocateTestMem(int64 length, uint64 paddr_base) {
+  // Try hugepages first.
+  void *buf = 0;
+
+  sat_assert(length >= 0);
+
+  if (paddr_base)
+    logprintf(0, "Process Error: non zero paddr_base %#llx is not supported,"
+              " ignore.\n", paddr_base);
+
+  // Determine optimal memory allocation path.
+  bool prefer_hugepages = false;
+  bool prefer_posix_shm = false;
+  bool prefer_dynamic_mapping = false;
+
+  // Are there enough hugepages?
+  int64 hugepagesize = FindHugePages() * 2 * kMegabyte;
+  // TODO(nsanders): Is there enough /dev/shm? Is there enough free memeory?
+  if ((length >= 1400LL * kMegabyte) && (address_mode_ == 32)) {
+    prefer_dynamic_mapping = true;
+    prefer_posix_shm = true;
+    logprintf(3, "Log: Prefer POSIX shared memory allocation.\n");
+    logprintf(3, "Log: You may need to run "
+                 "'sudo mount -o remount,size=100\% /dev/shm.'\n");
+  } else if (hugepagesize >= length) {
+    prefer_hugepages = true;
+    logprintf(3, "Log: Prefer using hugepace allocation.\n");
+  } else {
+    logprintf(3, "Log: Prefer plain malloc memory allocation.\n");
+  }
+
+  // Allocate hugepage mapped memory.
+  if (prefer_hugepages) {
+    do { // Allow break statement.
+      int shmid;
+      void *shmaddr;
+
+      if ((shmid = shmget(2, length,
+              SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W)) < 0) {
+        int err = errno;
+        string errtxt = ErrorString(err);
+        logprintf(3, "Log: failed to allocate shared hugepage "
+                      "object - err %d (%s)\n",
+                  err, errtxt.c_str());
+        logprintf(3, "Log: sysctl -w vm.nr_hugepages=XXX allows hugepages.\n");
+        break;
+      }
+
+      shmaddr = shmat(shmid, NULL, NULL);
+      if (shmaddr == reinterpret_cast<void*>(-1)) {
+        int err = errno;
+        string errtxt = ErrorString(err);
+        logprintf(0, "Log: failed to attach shared "
+                     "hugepage object - err %d (%s).\n",
+                  err, errtxt.c_str());
+        if (shmctl(shmid, IPC_RMID, NULL) < 0) {
+          int err = errno;
+          string errtxt = ErrorString(err);
+          logprintf(0, "Log: failed to remove shared "
+                       "hugepage object - err %d (%s).\n",
+                    err, errtxt.c_str());
+        }
+        break;
+      }
+      use_hugepages_ = true;
+      shmid_ = shmid;
+      buf = shmaddr;
+      logprintf(0, "Log: Using shared hugepage object 0x%x at %p.\n",
+                shmid, shmaddr);
+    } while (0);
+  }
+
+  if ((!use_hugepages_) && prefer_posix_shm) {
+    do {
+      int shm_object;
+      void *shmaddr = NULL;
+
+      shm_object = shm_open("/stressapptest", O_CREAT | O_RDWR, S_IRWXU);
+      if (shm_object < 0) {
+        int err = errno;
+        string errtxt = ErrorString(err);
+        logprintf(3, "Log: failed to allocate shared "
+                      "smallpage object - err %d (%s)\n",
+                  err, errtxt.c_str());
+        break;
+      }
+
+      if (0 > ftruncate(shm_object, length)) {
+        int err = errno;
+        string errtxt = ErrorString(err);
+        logprintf(3, "Log: failed to ftruncate shared "
+                      "smallpage object - err %d (%s)\n",
+                  err, errtxt.c_str());
+        break;
+      }
+
+      // 32 bit linux apps can only use ~1.4G of address space.
+      // Use dynamic mapping for allocations larger than that.
+      // Currently perf hit is ~10% for this.
+      if (prefer_dynamic_mapping) {
+        dynamic_mapped_shmem_ = true;
+      } else {
+        // Do a full mapping here otherwise.
+        shmaddr = mmap64(NULL, length, PROT_READ | PROT_WRITE,
+                         MAP_SHARED | MAP_NORESERVE | MAP_LOCKED | MAP_POPULATE,
+                         shm_object, NULL);
+        if (shmaddr == reinterpret_cast<void*>(-1)) {
+          int err = errno;
+          string errtxt = ErrorString(err);
+          logprintf(0, "Log: failed to map shared "
+                       "smallpage object - err %d (%s).\n",
+                    err, errtxt.c_str());
+          break;
+        }
+      }
+
+      use_posix_shm_ = true;
+      shmid_ = shm_object;
+      buf = shmaddr;
+      char location_message[256] = "";
+      if (dynamic_mapped_shmem_) {
+        sprintf(location_message, "mapped as needed");
+      } else {
+        sprintf(location_message, "at %p", shmaddr);
+      }
+      logprintf(0, "Log: Using posix shared memory object 0x%x %s.\n",
+                shm_object, location_message);
+    } while (0);
+    shm_unlink("/stressapptest");
+  }
+
+  if (!use_hugepages_ && !use_posix_shm_) {
+    // Use memalign to ensure that blocks are aligned enough for disk direct IO.
+    buf = static_cast<char*>(memalign(4096, length));
+    if (buf) {
+      logprintf(0, "Log: Using memaligned allocation at %p.\n", buf);
+    } else {
+      logprintf(0, "Process Error: memalign returned 0\n");
+      if ((length >= 1499LL * kMegabyte) && (address_mode_ == 32)) {
+        logprintf(0, "Log: You are trying to allocate > 1.4G on a 32 "
+                     "bit process. Please setup shared memory.\n");
+      }
+    }
+  }
+
+  testmem_ = buf;
+  if (buf || dynamic_mapped_shmem_) {
+    testmemsize_ = length;
+  } else {
+    testmemsize_ = 0;
+  }
+
+  return (buf != 0) || dynamic_mapped_shmem_;
+}
+
+// Free the test memory.
+void OsLayer::FreeTestMem() {
+  if (testmem_) {
+    if (use_hugepages_) {
+      shmdt(testmem_);
+      shmctl(shmid_, IPC_RMID, NULL);
+    } else if (use_posix_shm_) {
+      if (!dynamic_mapped_shmem_) {
+        munmap(testmem_, testmemsize_);
+      }
+      close(shmid_);
+    } else {
+      free(testmem_);
+    }
+    testmem_ = 0;
+    testmemsize_ = 0;
+  }
+}
+
+
+// Prepare the target memory. It may requre mapping in, or this may be a noop.
+void *OsLayer::PrepareTestMem(uint64 offset, uint64 length) {
+  sat_assert((offset + length) <= testmemsize_);
+  if (dynamic_mapped_shmem_) {
+    // TODO(nsanders): Check if we can support MAP_NONBLOCK,
+    // and evaluate performance hit from not using it.
+    void * mapping = mmap64(NULL, length, PROT_READ | PROT_WRITE,
+                     MAP_SHARED | MAP_NORESERVE | MAP_LOCKED | MAP_POPULATE,
+                     shmid_, offset);
+    if (mapping == MAP_FAILED) {
+      string errtxt = ErrorString(errno);
+      logprintf(0, "Process Error: PrepareTestMem mmap64(%llx, %llx) failed. "
+                   "error: %s.\n",
+                offset, length, errtxt.c_str());
+      sat_assert(0);
+    }
+    return mapping;
+  }
+
+  return reinterpret_cast<void*>(reinterpret_cast<char*>(testmem_) + offset);
+}
+
+// Release the test memory resources, if any.
+void OsLayer::ReleaseTestMem(void *addr, uint64 offset, uint64 length) {
+  if (dynamic_mapped_shmem_) {
+    int retval = munmap(addr, length);
+    if (retval == -1) {
+      string errtxt = ErrorString(errno);
+      logprintf(0, "Process Error: ReleaseTestMem munmap(%p, %llx) failed. "
+                   "error: %s.\n",
+                addr, length, errtxt.c_str());
+      sat_assert(0);
+    }
+  }
+}
+
+// No error polling on unknown systems.
+int OsLayer::ErrorPoll() {
+  return 0;
+}
+
+// Generally, poll for errors once per second.
+void OsLayer::ErrorWait() {
+  sat_sleep(1);
+  return;
+}
+
+// Open a PCI bus-dev-func as a file and return its file descriptor.
+// Error is indicated by return value less than zero.
+int OsLayer::PciOpen(int bus, int device, int function) {
+  char dev_file[256];
+
+  snprintf(dev_file, sizeof(dev_file), "/proc/bus/pci/%02x/%02x.%x",
+           bus, device, function);
+
+  int fd = open(dev_file, O_RDWR);
+  if (fd == -1) {
+    logprintf(0, "Process Error: Unable to open PCI bus %d, device %d, "
+                 "function %d (errno %d).\n",
+              bus, device, function, errno);
+    return -1;
+  }
+
+  return fd;
+}
+
+
+// Read and write functions to access PCI config.
+uint32 OsLayer::PciRead(int fd, uint32 offset, int width) {
+  // Strict aliasing rules lawyers will cause data corruption
+  // on cast pointers in some gccs.
+  union {
+    uint32 l32;
+    uint16 l16;
+    uint8 l8;
+  } datacast;
+  datacast.l32 = 0;
+  uint32 size = width / 8;
+
+  sat_assert((width == 32) || (width == 16) || (width == 8));
+  sat_assert(offset <= (256 - size));
+
+  if (lseek(fd, offset, SEEK_SET) < 0) {
+    logprintf(0, "Process Error: Can't seek %x\n", offset);
+    return 0;
+  }
+  if (read(fd, &datacast, size) != static_cast<ssize_t>(size)) {
+    logprintf(0, "Process Error: Can't read %x\n", offset);
+    return 0;
+  }
+
+  // Extract the data.
+  switch (width) {
+    case 8:
+      sat_assert(&(datacast.l8) == reinterpret_cast<uint8*>(&datacast));
+      return datacast.l8;
+    case 16:
+      sat_assert(&(datacast.l16) == reinterpret_cast<uint16*>(&datacast));
+      return datacast.l16;
+    case 32:
+      return datacast.l32;
+  }
+  return 0;
+}
+
+void OsLayer::PciWrite(int fd, uint32 offset, uint32 value, int width) {
+  // Strict aliasing rules lawyers will cause data corruption
+  // on cast pointers in some gccs.
+  union {
+    uint32 l32;
+    uint16 l16;
+    uint8 l8;
+  } datacast;
+  datacast.l32 = 0;
+  uint32 size = width / 8;
+
+  sat_assert((width == 32) || (width == 16) || (width == 8));
+  sat_assert(offset <= (256 - size));
+
+  // Cram the data into the right alignment.
+  switch (width) {
+    case 8:
+      sat_assert(&(datacast.l8) == reinterpret_cast<uint8*>(&datacast));
+      datacast.l8 = value;
+    case 16:
+      sat_assert(&(datacast.l16) == reinterpret_cast<uint16*>(&datacast));
+      datacast.l16 = value;
+    case 32:
+      datacast.l32 = value;
+  }
+
+  if (lseek(fd, offset, SEEK_SET) < 0) {
+    logprintf(0, "Process Error: Can't seek %x\n", offset);
+    return;
+  }
+  if (write(fd, &datacast, size) != static_cast<ssize_t>(size)) {
+    logprintf(0, "Process Error: Can't write %x to %x\n", datacast.l32, offset);
+    return;
+  }
+
+  return;
+}
+
+
+
+// Open dev msr.
+int OsLayer::OpenMSR(uint32 core, uint32 address) {
+  char buf[256];
+  snprintf(buf, sizeof(buf), "/dev/cpu/%d/msr", core);
+  int fd = open(buf, O_RDWR);
+  if (fd < 0)
+    return fd;
+
+  uint32 pos = lseek(fd, address, SEEK_SET);
+  if (pos != address) {
+    close(fd);
+    logprintf(5, "Log: can't seek to msr %x, cpu %d\n", address, core);
+    return -1;
+  }
+
+  return fd;
+}
+
+bool OsLayer::ReadMSR(uint32 core, uint32 address, uint64 *data) {
+  int fd = OpenMSR(core, address);
+  if (fd < 0)
+    return false;
+
+  // Read from the msr.
+  bool res = (sizeof(*data) == read(fd, data, sizeof(*data)));
+
+  if (!res)
+    logprintf(5, "Log: Failed to read msr %x core %d\n", address, core);
+
+  close(fd);
+
+  return res;
+}
+
+bool OsLayer::WriteMSR(uint32 core, uint32 address, uint64 *data) {
+  int fd = OpenMSR(core, address);
+  if (fd < 0)
+    return false;
+
+  // Write to the msr
+  bool res = (sizeof(*data) == write(fd, data, sizeof(*data)));
+
+  if (!res)
+    logprintf(5, "Log: Failed to write msr %x core %d\n", address, core);
+
+  close(fd);
+
+  return res;
+}
+
+// Extract bits [n+len-1, n] from a 32 bit word.
+// so GetBitField(0x0f00, 8, 4) == 0xf.
+uint32 OsLayer::GetBitField(uint32 val, uint32 n, uint32 len) {
+  return (val >> n) & ((1<<len) - 1);
+}
+
+// Generic CPU stress workload that would work on any CPU/Platform.
+// Float-point array moving average calculation.
+bool OsLayer::CpuStressWorkload() {
+  double float_arr[100];
+  double sum = 0;
+  unsigned int seed = 12345;
+
+  // Initialize array with random numbers.
+  for (int i = 0; i < 100; i++) {
+    float_arr[i] = rand_r(&seed);
+    if (rand_r(&seed) % 2)
+      float_arr[i] *= -1.0;
+  }
+
+  // Calculate moving average.
+  for (int i = 0; i < 100000000; i++) {
+    float_arr[i % 100] =
+      (float_arr[i % 100] + float_arr[(i + 1) % 100] +
+       float_arr[(i + 99) % 100]) / 3;
+    sum += float_arr[i % 100];
+  }
+
+  // Artificial printf so the loops do not get optimized away.
+  if (sum == 0.0)
+    logprintf(12, "Log: I'm Feeling Lucky!\n");
+  return true;
+}
+
+PCIDevices OsLayer::GetPCIDevices() {
+  PCIDevices device_list;
+  DIR *dir;
+  struct dirent *buf = new struct dirent();
+  struct dirent *entry;
+  dir = opendir(kSysfsPath);
+  if (!dir)
+    logprintf(0, "Process Error: Cannot open %s", kSysfsPath);
+  while (readdir_r(dir, buf, &entry) == 0 && entry) {
+    PCIDevice *device;
+    unsigned int dev, func;
+    // ".", ".." or a special non-device perhaps.
+    if (entry->d_name[0] == '.')
+      continue;
+
+    device = new PCIDevice();
+    if (sscanf(entry->d_name, "%04x:%02hx:%02x.%d",
+               &device->domain, &device->bus, &dev, &func) < 4) {
+      logprintf(0, "Process Error: Couldn't parse %s", entry->d_name);
+      free(device);
+      continue;
+    }
+    device->dev = dev;
+    device->func = func;
+    device->vendor_id = PCIGetValue(entry->d_name, "vendor");
+    device->device_id = PCIGetValue(entry->d_name, "device");
+    PCIGetResources(entry->d_name, device);
+    device_list.insert(device_list.end(), device);
+  }
+  closedir(dir);
+  delete buf;
+  return device_list;
+}
+
+int OsLayer::PCIGetValue(string name, string object) {
+  int fd, len;
+  char filename[256];
+  char buf[256];
+  snprintf(filename, sizeof(filename), "%s/%s/%s", kSysfsPath,
+           name.c_str(), object.c_str());
+  fd = open(filename, O_RDONLY);
+  if (fd < 0)
+    return 0;
+  len = read(fd, buf, 256);
+  close(fd);
+  buf[len] = '\0';
+  return strtol(buf, NULL, 0);  // NOLINT
+}
+
+int OsLayer::PCIGetResources(string name, PCIDevice *device) {
+  char filename[256];
+  char buf[256];
+  FILE *file;
+  int64 start;
+  int64 end;
+  int64 size;
+  int i;
+  snprintf(filename, sizeof(filename), "%s/%s/%s", kSysfsPath,
+           name.c_str(), "resource");
+  file = fopen(filename, "r");
+  if (!file) {
+    logprintf(0, "Process Error: impossible to find resource file for %s",
+              filename);
+    return errno;
+  }
+  for (i = 0; i < 6; i++) {
+    if (!fgets(buf, 256, file))
+      break;
+    sscanf(buf, "%llx %llx", &start, &end);  // NOLINT
+    size = 0;
+    if (start)
+      size = end - start + 1;
+    device->base_addr[i] = start;
+    device->size[i] = size;
+  }
+  fclose(file);
+  return 0;
+}
diff --git a/src/os.h b/src/os.h
new file mode 100644
index 0000000..28c8a2a
--- /dev/null
+++ b/src/os.h
@@ -0,0 +1,290 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+// Author: nsanders, menderico
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef STRESSAPPTEST_OS_H_  // NOLINT
+#define STRESSAPPTEST_OS_H_
+
+#include <dirent.h>
+#include <string>
+#include <list>
+#include <map>
+#include <vector>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "adler32memcpy.h"  // NOLINT
+#include "sattypes.h"       // NOLINT
+
+const char kSysfsPath[] = "/sys/bus/pci/devices";
+
+struct PCIDevice {
+  int32 domain;
+  uint16 bus;
+  uint8 dev;
+  uint8 func;
+  uint16 vendor_id;
+  uint16 device_id;
+  uint64 base_addr[6];
+  uint64 size[6];
+};
+
+typedef vector<PCIDevice*> PCIDevices;
+
+class ErrorDiag;
+
+// This class implements OS/Platform specific funtions.
+class OsLayer {
+ public:
+  OsLayer();
+  virtual ~OsLayer();
+
+  // Set the minimum amount of hugepages that should be available for testing.
+  // Must be set before Initialize().
+  void SetMinimumHugepagesSize(int64 min_bytes) {
+    min_hugepages_bytes_ = min_bytes;
+  }
+
+  // Initializes data strctures and open files.
+  // Returns false on error.
+  virtual bool Initialize();
+
+  // Virtual to physical. This implementation is optional for
+  // subclasses to implement.
+  // Takes a pointer, and returns the corresponding bus address.
+  virtual uint64 VirtualToPhysical(void *vaddr);
+
+  // Prints failed dimm. This implementation is optional for
+  // subclasses to implement.
+  // Takes a bus address and string, and prints the DIMM name
+  // into the string. Returns error status.
+  virtual int FindDimm(uint64 addr, char *buf, int len);
+  // Print dimm info, plus more available info.
+  virtual int FindDimmExtended(uint64 addr, char *buf, int len) {
+    return FindDimm(addr, buf, len);
+  }
+
+
+  // Classifies addresses according to "regions"
+  // This may mean different things on different platforms.
+  virtual int32 FindRegion(uint64 paddr);
+  // Find cpu cores associated with a region. Either NUMA or arbitrary.
+  virtual cpu_set_t *FindCoreMask(int32 region);
+  // Return cpu cores associated with a region in a hex string.
+  virtual string FindCoreMaskFormat(int32 region);
+
+  // Returns the HD device that contains this file.
+  virtual string FindFileDevice(string filename);
+
+  // Returns a list of paths coresponding to HD devices found on this machine.
+  virtual list<string> FindFileDevices();
+
+  // Polls for errors. This implementation is optional.
+  // This will poll once for errors and return zero iff no errors were found.
+  virtual int ErrorPoll();
+
+  // Delay an appropriate amount of time between polling.
+  virtual void ErrorWait();
+
+  // Report errors. This implementation is mandatory.
+  // This will output a machine readable line regarding the error.
+  virtual bool ErrorReport(const char *part, const char *symptom, int count);
+
+  // Flushes cacheline. Used to distinguish read or write errors.
+  // Subclasses may implement this in machine specific ways..
+  // Takes a pointer, and flushed the cacheline containing that pointer.
+  virtual void Flush(void *vaddr);
+
+  // Fast flush, for use in performance critical code.
+  // This is bound at compile time, and will not pick up
+  // any runtime machine configuration info.
+  inline static void FastFlush(void *vaddr) {
+#ifdef STRESSAPPTEST_CPU_PPC
+    asm volatile("dcbf 0,%0; sync" : : "r" (vaddr));
+#elif defined(STRESSAPPTEST_CPU_X86_64) || defined(STRESSAPPTEST_CPU_I686)
+    // Put mfence before and after clflush to make sure:
+    // 1. The write before the clflush is committed to memory bus;
+    // 2. The read after the clflush is hitting the memory bus.
+    //
+    // From Intel manual:
+    // CLFLUSH is only ordered by the MFENCE instruction. It is not guaranteed
+    // to be ordered by any other fencing, serializing or other CLFLUSH
+    // instruction. For example, software can use an MFENCE instruction to
+    // insure that previous stores are included in the write-back.
+    asm volatile("mfence");
+    asm volatile("clflush (%0)" :: "r" (vaddr));
+    asm volatile("mfence");
+#elif defined(STRESSAPPTEST_CPU_ARMV7A)
+  #warning "Unsupported CPU type ARMV7A: Unable to force cache flushes."
+#else
+  #warning "Unsupported CPU type: Unable to force cache flushes."
+#endif
+  }
+
+  // Get time in cpu timer ticks. Useful for matching MCEs with software
+  // actions.
+  inline static uint64 GetTimestamp(void) {
+    uint64 tsc;
+#ifdef STRESSAPPTEST_CPU_PPC
+    uint32 tbl, tbu, temp;
+    __asm __volatile(
+      "1:\n"
+      "mftbu  %2\n"
+      "mftb   %0\n"
+      "mftbu  %1\n"
+      "cmpw   %2,%1\n"
+      "bne    1b\n"
+      : "=r"(tbl), "=r"(tbu), "=r"(temp)
+      :
+      : "cc");
+
+    tsc = (static_cast<uint64>(tbu) << 32) | static_cast<uint64>(tbl);
+#elif defined(STRESSAPPTEST_CPU_X86_64) || defined(STRESSAPPTEST_CPU_I686)
+    datacast_t data;
+    __asm __volatile("rdtsc" : "=a" (data.l32.l), "=d"(data.l32.h));
+    tsc = data.l64;
+#elif defined(STRESSAPPTEST_CPU_ARMV7A)
+  #warning "Unsupported CPU type ARMV7A: your build may not function correctly"
+    tsc = 0;
+#else
+  #warning "Unsupported CPU type: your build may not function correctly"
+    tsc = 0;
+#endif
+    return (tsc);
+  }
+
+  // Find the free memory on the machine.
+  virtual int64 FindFreeMemSize();
+
+  // Allocates test memory of length bytes.
+  // Subclasses must implement this.
+  // Call PepareTestMem to get a pointer.
+  virtual int64 AllocateAllMem();  // Returns length.
+  // Returns success.
+  virtual bool AllocateTestMem(int64 length, uint64 paddr_base);
+  virtual void FreeTestMem();
+
+  // Prepares the memory for use. You must call this
+  // before using test memory, and after you are done.
+  virtual void *PrepareTestMem(uint64 offset, uint64 length);
+  virtual void ReleaseTestMem(void *addr, uint64 offset, uint64 length);
+
+  // Machine type detected. Can we implement all these functions correctly?
+  // Returns true if machine type is detected and implemented.
+  virtual bool IsSupported();
+
+  // Returns 32 for 32-bit, 64 for 64-bit.
+  virtual int AddressMode();
+  // Update OsLayer state regarding cpu support for various features.
+  virtual void GetFeatures();
+
+  // Open, read, write pci cfg through /proc/bus/pci. fd is /proc/pci file.
+  virtual int PciOpen(int bus, int device, int function);
+  virtual void PciWrite(int fd, uint32 offset, uint32 value, int width);
+  virtual uint32 PciRead(int fd, uint32 offset, int width);
+
+  // Read MSRs
+  virtual bool ReadMSR(uint32 core, uint32 address, uint64 *data);
+  virtual bool WriteMSR(uint32 core, uint32 address, uint64 *data);
+
+  // Extract bits [n+len-1, n] from a 32 bit word.
+  // so GetBitField(0x0f00, 8, 4) == 0xf.
+  virtual uint32 GetBitField(uint32 val, uint32 n, uint32 len);
+
+  // Platform and CPU specific CPU-stressing function.
+  // Returns true on success, false otherwise.
+  virtual bool CpuStressWorkload();
+
+  // Causes false errors for unittesting.
+  // Setting to "true" causes errors to be injected.
+  void set_error_injection(bool errors) { error_injection_ = errors; }
+  bool error_injection() const { return error_injection_; }
+
+  // Is SAT using normal malloc'd memory, or exotic mmap'd memory.
+  bool normal_mem() const { return normal_mem_; }
+
+  // Get numa config, if available..
+  int num_nodes() const { return num_nodes_; }
+  int num_cpus() const { return num_cpus_; }
+
+  // Handle to platform-specific error diagnoser.
+  ErrorDiag *error_diagnoser_;
+
+  // Detect all PCI Devices.
+  virtual PCIDevices GetPCIDevices();
+
+  // Disambiguate between different "warm" memcopies.
+  virtual bool AdlerMemcpyWarm(uint64 *dstmem, uint64 *srcmem,
+                               unsigned int size_in_bytes,
+                               AdlerChecksum *checksum);
+
+  // Store a callback to use to print
+  // app-specific info about the last error location.
+  // This call back is called with a physical address, and the app can fill in
+  // the most recent transaction that occurred at that address.
+  typedef bool (*ErrCallback)(uint64 paddr, string *buf);
+  void set_err_log_callback(
+    ErrCallback err_log_callback) {
+    err_log_callback_ = err_log_callback;
+  }
+  ErrCallback get_err_log_callback() { return err_log_callback_; }
+
+ protected:
+  void *testmem_;                // Location of test memory.
+  uint64 testmemsize_;           // Size of test memory.
+  int64 totalmemsize_;           // Size of available memory.
+  int64 min_hugepages_bytes_;    // Minimum hugepages size.
+  bool  error_injection_;        // Do error injection?
+  bool  normal_mem_;             // Memory DMA capable?
+  bool  use_hugepages_;          // Use hugepage shmem?
+  bool  use_posix_shm_;          // Use 4k page shmem?
+  bool  dynamic_mapped_shmem_;   // Conserve virtual address space.
+  int   shmid_;                  // Handle to shmem
+
+  int64 regionsize_;             // Size of memory "regions"
+  int   regioncount_;            // Number of memory "regions"
+  int   num_cpus_;               // Number of cpus in the system.
+  int   num_nodes_;              // Number of nodes in the system.
+  int   num_cpus_per_node_;      // Number of cpus per node in the system.
+  int   address_mode_;           // Are we running 32 or 64 bit?
+  bool  has_sse2_;               // Do we have sse2 instructions?
+  bool  has_clflush_;            // Do we have clflush instructions?
+
+
+  time_t time_initialized_;      // Start time of test.
+
+  vector<cpu_set_t> cpu_sets_;   // Cache for cpu masks.
+  vector<bool> cpu_sets_valid_;  // If the cpu mask cache is valid.
+
+  // Get file descriptor for dev msr.
+  virtual int OpenMSR(uint32 core, uint32 address);
+  // Auxiliary methods for PCI device configuration
+  int PCIGetValue(string name, string object);
+  int PCIGetResources(string name, PCIDevice *device);
+
+  // Look up how many hugepages there are.
+  virtual int64 FindHugePages();
+
+  // Link to find last transaction at an error location.
+  ErrCallback err_log_callback_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(OsLayer);
+};
+
+// Selects and returns the proper OS and hardware interface.  Does not call
+// OsLayer::Initialize() on the new object.
+OsLayer *OsLayerFactory(const std::map<std::string, std::string> &options);
+
+#endif  // STRESSAPPTEST_OS_H_ NOLINT
diff --git a/src/os_factory.cc b/src/os_factory.cc
new file mode 100644
index 0000000..359f7ee
--- /dev/null
+++ b/src/os_factory.cc
@@ -0,0 +1,40 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file generates an OS interface class consistant with the
+// current machine type. No machine type detection is currently done.
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <string.h>
+
+#include <map>
+#include <string>
+
+#include "os.h"
+
+
+// Select the proper OS and hardware interface.
+OsLayer *OsLayerFactory(const std::map<std::string, std::string> &options) {
+  OsLayer *os = 0;
+  os = new OsLayer();
+
+  // Check for memory allocation failure.
+  if (!os) {
+    logprintf(0, "Process Error: Can't allocate memory\n");
+    return 0;
+  }
+  return os;
+}
diff --git a/src/pattern.cc b/src/pattern.cc
new file mode 100644
index 0000000..9f22674
--- /dev/null
+++ b/src/pattern.cc
@@ -0,0 +1,421 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// pattern.cc : library of stressful data patterns
+
+#include <sys/types.h>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "pattern.h"
+#include "sattypes.h"
+
+// Static data patterns.
+
+static unsigned int walkingOnes_data[] =   {
+  0x00000001, 0x00000002, 0x00000004, 0x00000008,
+  0x00000010, 0x00000020, 0x00000040, 0x00000080,
+  0x00000100, 0x00000200, 0x00000400, 0x00000800,
+  0x00001000, 0x00002000, 0x00004000, 0x00008000,
+  0x00010000, 0x00020000, 0x00040000, 0x00080000,
+  0x00100000, 0x00200000, 0x00400000, 0x00800000,
+  0x01000000, 0x02000000, 0x04000000, 0x08000000,
+  0x10000000, 0x20000000, 0x40000000, 0x80000000,
+  0x40000000, 0x20000000, 0x10000000, 0x08000000,
+  0x04000000, 0x02000000, 0x01000000, 0x00800000,
+  0x00400000, 0x00200000, 0x00100000, 0x00080000,
+  0x00040000, 0x00020000, 0x00010000, 0x00008000,
+  0x00004000, 0x00002000, 0x00001000, 0x00000800,
+  0x00000400, 0x00000200, 0x00000100, 0x00000080,
+  0x00000040, 0x00000020, 0x00000010, 0x00000008,
+  0x00000004, 0x00000002, 0x00000001, 0x00000000
+};
+static const struct PatternData walkingOnes = {
+  "walkingOnes",
+  walkingOnes_data,
+  (sizeof walkingOnes_data / sizeof walkingOnes_data[0]) - 1,
+  {1, 1, 2, 1}  // Weight for choosing 32/64/128/256 bit wide of this pattern
+};
+
+static unsigned int walkingInvOnes_data[] =   {
+  0x00000001, 0xfffffffe, 0x00000002, 0xfffffffd,
+  0x00000004, 0xfffffffb, 0x00000008, 0xfffffff7,
+  0x00000010, 0xffffffef, 0x00000020, 0xffffffdf,
+  0x00000040, 0xffffffbf, 0x00000080, 0xffffff7f,
+  0x00000100, 0xfffffeff, 0x00000200, 0xfffffdff,
+  0x00000400, 0xfffffbff, 0x00000800, 0xfffff7ff,
+  0x00001000, 0xffffefff, 0x00002000, 0xffffdfff,
+  0x00004000, 0xffffbfff, 0x00008000, 0xffff7fff,
+  0x00010000, 0xfffeffff, 0x00020000, 0xfffdffff,
+  0x00040000, 0xfffbffff, 0x00080000, 0xfff7ffff,
+  0x00100000, 0xffefffff, 0x00200000, 0xffdfffff,
+  0x00400000, 0xffbfffff, 0x00800000, 0xff7fffff,
+  0x01000000, 0xfeffffff, 0x02000000, 0xfdffffff,
+  0x04000000, 0xfbffffff, 0x08000000, 0xf7ffffff,
+  0x10000000, 0xefffffff, 0x20000000, 0xdfffffff,
+  0x40000000, 0xbfffffff, 0x80000000, 0x7fffffff,
+  0x40000000, 0xbfffffff, 0x20000000, 0xdfffffff,
+  0x10000000, 0xefffffff, 0x08000000, 0xf7ffffff,
+  0x04000000, 0xfbffffff, 0x02000000, 0xfdffffff,
+  0x01000000, 0xfeffffff, 0x00800000, 0xff7fffff,
+  0x00400000, 0xffbfffff, 0x00200000, 0xffdfffff,
+  0x00100000, 0xffefffff, 0x00080000, 0xfff7ffff,
+  0x00040000, 0xfffbffff, 0x00020000, 0xfffdffff,
+  0x00010000, 0xfffeffff, 0x00008000, 0xffff7fff,
+  0x00004000, 0xffffbfff, 0x00002000, 0xffffdfff,
+  0x00001000, 0xffffefff, 0x00000800, 0xfffff7ff,
+  0x00000400, 0xfffffbff, 0x00000200, 0xfffffdff,
+  0x00000100, 0xfffffeff, 0x00000080, 0xffffff7f,
+  0x00000040, 0xffffffbf, 0x00000020, 0xffffffdf,
+  0x00000010, 0xffffffef, 0x00000008, 0xfffffff7,
+  0x00000004, 0xfffffffb, 0x00000002, 0xfffffffd,
+  0x00000001, 0xfffffffe, 0x00000000, 0xffffffff
+};
+static const struct PatternData walkingInvOnes = {
+  "walkingInvOnes",
+  walkingInvOnes_data,
+  (sizeof walkingInvOnes_data / sizeof walkingInvOnes_data[0]) - 1,
+  {2, 2, 5, 5}
+};
+
+static unsigned int walkingZeros_data[] =   {
+  0xfffffffe, 0xfffffffd, 0xfffffffb, 0xfffffff7,
+  0xffffffef, 0xffffffdf, 0xffffffbf, 0xffffff7f,
+  0xfffffeff, 0xfffffdff, 0xfffffbff, 0xfffff7ff,
+  0xffffefff, 0xffffdfff, 0xffffbfff, 0xffff7fff,
+  0xfffeffff, 0xfffdffff, 0xfffbffff, 0xfff7ffff,
+  0xffefffff, 0xffdfffff, 0xffbfffff, 0xff7fffff,
+  0xfeffffff, 0xfdffffff, 0xfbffffff, 0xf7ffffff,
+  0xefffffff, 0xdfffffff, 0xbfffffff, 0x7fffffff,
+  0xbfffffff, 0xdfffffff, 0xefffffff, 0xf7ffffff,
+  0xfbffffff, 0xfdffffff, 0xfeffffff, 0xff7fffff,
+  0xffbfffff, 0xffdfffff, 0xffefffff, 0xfff7ffff,
+  0xfffbffff, 0xfffdffff, 0xfffeffff, 0xffff7fff,
+  0xffffbfff, 0xffffdfff, 0xffffefff, 0xfffff7ff,
+  0xfffffbff, 0xfffffdff, 0xfffffeff, 0xffffff7f,
+  0xffffffbf, 0xffffffdf, 0xffffffef, 0xfffffff7,
+  0xfffffffb, 0xfffffffd, 0xfffffffe, 0xffffffff
+};
+static const struct PatternData walkingZeros = {
+  "walkingZeros",
+  walkingZeros_data,
+  (sizeof walkingZeros_data / sizeof walkingZeros_data[0]) - 1,
+  {1, 1, 2, 1}
+};
+
+static unsigned int OneZero_data[] =   { 0x00000000, 0xffffffff};
+static const struct PatternData OneZero = {
+  "OneZero",
+  OneZero_data,
+  (sizeof OneZero_data / sizeof OneZero_data[0]) - 1,
+  {5, 5, 15, 5}
+};
+
+static unsigned int JustZero_data[] =   { 0x00000000, 0x00000000};
+static const struct PatternData JustZero = {
+  "JustZero",
+  JustZero_data,
+  (sizeof JustZero_data / sizeof JustZero_data[0]) - 1,
+  {2, 0, 0, 0}
+};
+
+static unsigned int JustOne_data[] =   { 0xffffffff, 0xffffffff};
+static const struct PatternData JustOne = {
+  "JustOne",
+  JustOne_data,
+  (sizeof JustOne_data / sizeof JustOne_data[0]) - 1,
+  {2, 0, 0, 0}
+};
+
+static unsigned int JustFive_data[] =   { 0x55555555, 0x55555555};
+static const struct PatternData JustFive = {
+  "JustFive",
+  JustFive_data,
+  (sizeof JustFive_data / sizeof JustFive_data[0]) - 1,
+  {2, 0, 0, 0}
+};
+
+static unsigned int JustA_data[] =   { 0xaaaaaaaa, 0xaaaaaaaa};
+static const struct PatternData JustA = {
+  "JustA",
+  JustA_data,
+  (sizeof JustA_data / sizeof JustA_data[0]) - 1,
+  {2, 0, 0, 0}
+};
+
+static unsigned int FiveA_data[] =   { 0x55555555, 0xaaaaaaaa};
+static const struct PatternData FiveA = {
+  "FiveA",
+  FiveA_data,
+  (sizeof FiveA_data / sizeof FiveA_data[0]) - 1,
+  {1, 1, 1, 1}
+};
+
+static unsigned int FiveA8_data[] =   {
+  0x5aa5a55a, 0xa55a5aa5, 0xa55a5aa5, 0x5aa5a55a
+};
+static const struct PatternData FiveA8 = {
+  "FiveA8",
+  FiveA8_data,
+  (sizeof FiveA8_data / sizeof FiveA8_data[0]) - 1,
+  {1, 1, 1, 1}
+};
+
+static unsigned int Long8b10b_data[] =   { 0x16161616, 0x16161616 };
+static const struct PatternData Long8b10b = {
+  "Long8b10b",
+  Long8b10b_data,
+  (sizeof Long8b10b_data / sizeof Long8b10b_data[0]) - 1,
+  {2, 0, 0, 0}
+};
+
+static unsigned int Short8b10b_data[] =   { 0xb5b5b5b5, 0xb5b5b5b5 };
+static const struct PatternData Short8b10b = {
+  "Short8b10b",
+  Short8b10b_data,
+  (sizeof Short8b10b_data / sizeof Short8b10b_data[0]) - 1,
+  {2, 0, 0, 0}
+};
+
+static unsigned int Checker8b10b_data[] =   { 0xb5b5b5b5, 0x4a4a4a4a };
+static const struct PatternData Checker8b10b = {
+  "Checker8b10b",
+  Checker8b10b_data,
+  (sizeof Checker8b10b_data / sizeof Checker8b10b_data[0]) - 1,
+  {1, 0, 0, 1}
+};
+
+static unsigned int Five7_data[] =   { 0x55555557, 0x55575555 };
+static const struct PatternData Five7 = {
+  "Five7",
+  Five7_data,
+  (sizeof Five7_data / sizeof Five7_data[0]) - 1,
+  {0, 2, 0, 0}
+};
+
+static unsigned int Zero2fd_data[] =   { 0x00020002, 0xfffdfffd };
+static const struct PatternData Zero2fd = {
+  "Zero2fd",
+  Zero2fd_data,
+  (sizeof Zero2fd_data / sizeof Zero2fd_data[0]) - 1,
+  {0, 2, 0, 0}
+};
+
+// Extern array of useable patterns.
+static const struct PatternData pattern_array[] = {
+  walkingOnes,
+  walkingInvOnes,
+  walkingZeros,
+  OneZero,
+  JustZero,
+  JustOne,
+  JustFive,
+  JustA,
+  FiveA,
+  FiveA8,
+  Long8b10b,
+  Short8b10b,
+  Checker8b10b,
+  Five7,
+  Zero2fd,
+};
+static const int pattern_array_size =
+    sizeof pattern_array / sizeof pattern_array[0];
+
+Pattern::Pattern() {
+  crc_ = NULL;
+}
+
+Pattern::~Pattern() {
+  if (crc_ != NULL) {
+    delete crc_;
+  }
+}
+
+// Calculate CRC for this pattern. This must match
+// the CRC calculation in worker.cc.
+int Pattern::CalculateCrc() {
+  // TODO(johnhuang):
+  // Consider refactoring to the form:
+  // while (i < count) AdlerInc(uint64, uint64, AdlerChecksum*)
+  uint64 a1 = 1;
+  uint64 a2 = 1;
+  uint64 b1 = 0;
+  uint64 b2 = 0;
+
+  // checksum is calculated using only the first 4096 bytes of data.
+  int i = 0;
+  int blocksize = 4096;
+  int count = blocksize / sizeof i;
+  while (i < count) {
+    a1 += pattern(i);
+    b1 += a1;
+    i++;
+    a1 += pattern(i);
+    b1 += a1;
+    i++;
+
+    a2 += pattern(i);
+    b2 += a2;
+    i++;
+    a2 += pattern(i);
+    b2 += a2;
+    i++;
+  }
+  if (crc_ != NULL) {
+    delete crc_;
+  }
+  crc_ = new AdlerChecksum();
+  crc_->Set(a1, a2, b1, b2);
+  return 0;
+}
+
+// Initialize pattern's CRC.
+int Pattern::Initialize(const struct PatternData &pattern_init,
+                        int buswidth,
+                        bool invert,
+                        int weight) {
+  int result = 1;
+
+  pattern_ = &pattern_init;
+  busshift_ = 2;
+  inverse_ = invert;
+  weight_ = weight;
+
+  name_.clear();
+  name_.append(pattern_->name);
+
+  if (invert)
+    name_.append("~");
+
+  if (buswidth == 32) {
+    name_.append("32");
+    busshift_ = 0;
+  } else if (buswidth == 64) {
+    name_.append("64");
+    busshift_ = 1;
+  } else if (buswidth == 128) {
+    name_.append("128");
+    busshift_ = 2;
+  } else if (buswidth == 256) {
+    name_.append("256");
+    busshift_ = 3;
+  } else {
+    logprintf(0, "Process Error: Confused by bus width %d\n",
+              buswidth);
+    name_.append("Broken");
+    result = 0;
+  }
+
+  CalculateCrc();
+
+  return result;
+}
+
+
+PatternList::PatternList() {
+  size_= 0;
+  initialized_ = 0;
+}
+
+PatternList::~PatternList() {
+  if (initialized_) {
+    Destroy();
+  }
+}
+
+// Fill in the class with references to the static data patterns
+int PatternList::Initialize() {
+  int patterncount = 0;
+  int weightcount = 0;
+
+  patterns_.resize(pattern_array_size * 8);
+  for (int i = 0; i < pattern_array_size; i++) {
+    // Non inverted.
+    weightcount += pattern_array[i].weight[0];
+    patterns_[patterncount++].Initialize(pattern_array[i], 32, false,
+                                         pattern_array[i].weight[0]);
+    weightcount += pattern_array[i].weight[1];
+    patterns_[patterncount++].Initialize(pattern_array[i], 64, false,
+                                         pattern_array[i].weight[1]);
+    weightcount += pattern_array[i].weight[2];
+    patterns_[patterncount++].Initialize(pattern_array[i], 128, false,
+                                         pattern_array[i].weight[2]);
+    weightcount += pattern_array[i].weight[3];
+    patterns_[patterncount++].Initialize(pattern_array[i], 256, false,
+                                         pattern_array[i].weight[3]);
+
+    // Inverted.
+    weightcount += pattern_array[i].weight[0];
+    patterns_[patterncount++].Initialize(pattern_array[i], 32, true,
+                                         pattern_array[i].weight[0]);
+    weightcount += pattern_array[i].weight[1];
+    patterns_[patterncount++].Initialize(pattern_array[i], 64, true,
+                                         pattern_array[i].weight[1]);
+    weightcount += pattern_array[i].weight[2];
+    patterns_[patterncount++].Initialize(pattern_array[i], 128, true,
+                                         pattern_array[i].weight[2]);
+    weightcount += pattern_array[i].weight[3];
+    patterns_[patterncount++].Initialize(pattern_array[i], 256, true,
+                                         pattern_array[i].weight[3]);
+  }
+  size_ = patterncount;
+  weightcount_ = weightcount;
+  initialized_ = 1;
+
+  logprintf(12, "Log: initialized %d data patterns\n", size_);
+
+  return 1;
+}
+
+// Free the stuff.
+int PatternList::Destroy() {
+  if (!initialized_)
+    return 0;
+
+  patterns_.clear();
+  size_ = 0;
+  initialized_ = 0;
+
+  return 1;
+}
+
+// Return pattern numbered "i"
+Pattern *PatternList::GetPattern(int i) {
+  if (static_cast<unsigned int>(i) < size_) {
+    return &patterns_[i];
+  }
+
+  logprintf(0, "Process Error: Out of bounds pattern access\n");
+  return 0;
+}
+
+// Return a randomly selected pattern.
+Pattern *PatternList::GetRandomPattern() {
+  unsigned int target = random();
+  target = target % weightcount_;
+
+  unsigned int i = 0;
+  unsigned int sum = 0;
+  while (target > sum) {
+    sum += patterns_[i].weight();
+    i++;
+  }
+  if (i < size_) {
+    return &patterns_[i];
+  }
+
+  logprintf(0, "Process Error: Out of bounds pattern access\n");
+  return 0;
+}
diff --git a/src/pattern.h b/src/pattern.h
new file mode 100644
index 0000000..181f839
--- /dev/null
+++ b/src/pattern.h
@@ -0,0 +1,124 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// pattern.h : global pattern references and initialization
+
+// This file implements easy access to statically declared
+// data patterns.
+
+#ifndef STRESSAPPTEST_PATTERN_H_
+#define STRESSAPPTEST_PATTERN_H_
+
+#include <vector>
+#include <string>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "adler32memcpy.h"
+#include "sattypes.h"
+
+// 2 = 128 bit bus, 1 = 64 bit bus, 0 = 32 bit bus
+const int kBusShift = 2;
+
+// Pattern and CRC data structure
+struct PatternData {
+  const char *name;          // Name of this pattern.
+  unsigned int *pat;         // Data array.
+  unsigned int mask;         // Size - 1. data[index & mask] is always valid.
+  unsigned char weight[4];   // Weighted frequency of this pattern.
+                             // Each pattern has 32,64,128,256 width versions.
+                             // All weights are added up, a random number is
+                             // chosen between 0-sum(weights), and the
+                             // appropriate pattern is chosen. Thus a weight of
+                             // 1 is rare, a weight of 10 is 2x as likely to be
+                             // chosen as a weight of 5.
+};
+
+// Data structure to access data patterns.
+class Pattern {
+ public:
+  Pattern();
+  ~Pattern();
+  // Fill pattern data and calculate CRC.
+  int Initialize(const struct PatternData &pattern_init,
+                 int buswidth,
+                 bool invert,
+                 int weight);
+
+  // Access data members.
+  // "busshift_" allows for repeating each pattern word 1, 2, 4, etc. times.
+  // in order to create patterns of different width.
+  unsigned int pattern(unsigned int offset) {
+    unsigned int data = pattern_->pat[(offset >> busshift_) & pattern_->mask];
+    if (inverse_)
+      data = ~data;
+    return data;
+  }
+  const AdlerChecksum *crc() {return crc_;}
+  unsigned int mask() {return pattern_->mask;}
+  unsigned int weight() {return weight_;}
+  const char *name() {return name_.c_str();}
+
+ private:
+  int CalculateCrc();
+  const struct PatternData *pattern_;
+  int busshift_;        // Target data bus width.
+  bool inverse_;        // Invert the data from the original pattern.
+  AdlerChecksum *crc_;  // CRC of this pattern.
+  string name_;         // The human readable pattern name.
+  int weight_;          // This is the likelihood that this
+                        // pattern will be chosen.
+  // We want to copy this!
+  // DISALLOW_COPY_AND_ASSIGN(Pattern);
+};
+
+// Object used to access global pattern list.
+class PatternList {
+ public:
+  PatternList();
+  ~PatternList();
+  // Initialize pointers to global data patterns, and calculate CRC.
+  int Initialize();
+  int Destroy();
+
+  // Return the pattern designated by index i.
+  Pattern *GetPattern(int i);
+  // Return a random pattern according to the specified weighted probability.
+  Pattern *GetRandomPattern();
+  // Return the number of patterns available.
+  int Size() {return size_;}
+
+ private:
+  vector<class Pattern> patterns_;
+  int weightcount_;  // Total count of pattern weights.
+  unsigned int size_;
+  int initialized_;
+  DISALLOW_COPY_AND_ASSIGN(PatternList);
+};
+
+// CrcIncrement allows an abstracted way to add a 32bit
+// value into a running CRC. This function should be fast, and
+// generate meaningful CRCs for the types of data patterns that
+// we are using here.
+// This CRC formula may not be optimal, but it does work.
+// It may be improved in the future.
+static inline uint32 CrcIncrement(uint32 crc, uint32 expected, int index) {
+  uint32 addition = (expected ^ index);
+  uint32 carry = (addition & crc) >> 31;
+
+  return crc + addition + carry;
+}
+
+
+#endif  // STRESSAPPTEST_PATTERN_H_
diff --git a/src/queue.cc b/src/queue.cc
new file mode 100644
index 0000000..d735e68
--- /dev/null
+++ b/src/queue.cc
@@ -0,0 +1,118 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// queue.cc : simple thread safe queue implementation
+
+#include <stdlib.h>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "queue.h"
+#include "sattypes.h"
+
+// Page entry queue implementation follows.
+// Push inserts pages, pop returns a random entry.
+
+
+PageEntryQueue::PageEntryQueue(uint64 queuesize) {
+  // There must always be one empty queue location,
+  // since in == out => empty.
+  q_size_ = queuesize + 1;
+  pages_ = new struct page_entry[q_size_];
+  nextin_ = 0;
+  nextout_ = 0;
+  popped_ = 0;
+  pushed_ = 0;
+  pthread_mutex_init(&q_mutex_, NULL);
+}
+PageEntryQueue::~PageEntryQueue() {
+  delete[] pages_;
+  pthread_mutex_destroy(&q_mutex_);
+}
+
+// Add a page into this queue.
+int PageEntryQueue::Push(struct page_entry *pe) {
+  int result = 0;
+  int64 nextnextin;
+
+  if (!pe)
+    return 0;
+
+  pthread_mutex_lock(&q_mutex_);
+  nextnextin = (nextin_ + 1) % q_size_;
+
+  if (nextnextin != nextout_) {
+    pages_[nextin_] = *pe;
+
+    nextin_ = nextnextin;
+    result = 1;
+
+    pushed_++;
+  }
+
+  pthread_mutex_unlock(&q_mutex_);
+
+  return result;
+}
+
+// Retrieve a random page from this queue.
+int PageEntryQueue::PopRandom(struct page_entry *pe) {
+  int result = 0;
+  int64 lastin;
+  int64 entries;
+  int64 newindex;
+  struct page_entry tmp;
+
+  if (!pe)
+    return 0;
+
+  // TODO(nsanders): we should improve random to get 64 bit randoms, and make
+  // it more thread friendly.
+  uint64 rand = random();
+
+  int retval = pthread_mutex_lock(&q_mutex_);
+  if (retval)
+    logprintf(0, "Process Error: pthreads mutex failure %d\n", retval);
+
+
+  if (nextin_ != nextout_) {
+    // Randomized fetch.
+    // Swap random entry with next out.
+    {
+      lastin = (nextin_ - 1 + q_size_) % q_size_;
+      entries = (lastin - nextout_ + q_size_) % q_size_;
+
+      newindex = nextout_;
+      if (entries)
+        newindex = ((rand % entries) + nextout_) % q_size_;
+
+      // Swap the pages.
+      tmp = pages_[nextout_];
+      pages_[nextout_] = pages_[newindex];
+      pages_[newindex] = tmp;
+    }
+
+    // Return next out page.
+    *pe = pages_[nextout_];
+
+    nextout_ = (nextout_ + 1) % q_size_;
+    result = 1;
+
+    popped_++;
+  }
+
+  pthread_mutex_unlock(&q_mutex_);
+
+  return result;
+}
diff --git a/src/queue.h b/src/queue.h
new file mode 100644
index 0000000..a6296b1
--- /dev/null
+++ b/src/queue.h
@@ -0,0 +1,85 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// queue.h : simple queue api
+
+// This is an interface to a simple thread safe queue,
+// used to hold data blocks and patterns.
+// The order in which the blocks are returned is random.
+
+#ifndef STRESSAPPTEST_QUEUE_H_  // NOLINT
+#define STRESSAPPTEST_QUEUE_H_
+
+#include <sys/types.h>
+#include <pthread.h>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "sattypes.h"  // NOLINT
+#include "pattern.h"   // NOLINT
+
+// Tag indicating no preference.
+static const int kDontCareTag = -1;
+// Tag indicating no preference.
+static const int kInvalidTag = 0xf001;
+
+
+// This describes a block of memory, and the expected fill pattern.
+struct page_entry {
+  uint64 offset;
+  void *addr;
+  uint64 paddr;
+  class Pattern *pattern;
+  int32 tag;     // These are tags for use in NUMA affinity or other uses.
+  uint32 touch;  // Counter of the number of reads from this page.
+  uint64 ts;     // Timestamp of the last read from this page.
+  class Pattern *lastpattern;  // Expected Pattern at last read.
+};
+
+static inline void init_pe(struct page_entry *pe) {
+  pe->offset = 0;
+  pe->addr = NULL;
+  pe->pattern = NULL;
+  pe->tag = kInvalidTag;
+  pe->touch = 0;
+  pe->ts = 0;
+  pe->lastpattern = NULL;
+}
+
+// This is a threadsafe randomized queue of pages for
+// worker threads to use.
+class PageEntryQueue {
+ public:
+  explicit PageEntryQueue(uint64 queuesize);
+  ~PageEntryQueue();
+
+  // Push a page onto the list.
+  int Push(struct page_entry *pe);
+  // Pop a random page off of the list.
+  int PopRandom(struct page_entry *pe);
+
+ private:
+  struct page_entry *pages_;  // Where the pages are held.
+  int64 nextin_;
+  int64 nextout_;
+  int64 q_size_;  // Size of the queue.
+  int64 pushed_;  // Number of pages pushed, total.
+  int64 popped_;  // Number of pages popped, total.
+  pthread_mutex_t q_mutex_;
+
+  DISALLOW_COPY_AND_ASSIGN(PageEntryQueue);
+};
+
+
+#endif  // MILES_TESTS_SAT_QUEUE_H_ NOLINT
diff --git a/src/sat.cc b/src/sat.cc
new file mode 100644
index 0000000..bed62b7
--- /dev/null
+++ b/src/sat.cc
@@ -0,0 +1,1890 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// sat.cc : a stress test for stressful testing
+
+// stressapptest (or SAT, from Stressful Application Test) is a test
+// designed to stress the system, as well as provide a comprehensive
+// memory interface test.
+
+// stressapptest can be run using memory only, or using many system components.
+
+#include <errno.h>
+#include <pthread.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/stat.h>
+#include <sys/times.h>
+
+// #define __USE_GNU
+// #define __USE_LARGEFILE64
+#include <fcntl.h>
+
+#include <list>
+#include <string>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "disk_blocks.h"
+#include "logger.h"
+#include "os.h"
+#include "sat.h"
+#include "sattypes.h"
+#include "worker.h"
+
+// stressapptest versioning here.
+#ifndef PACKAGE_VERSION
+static const char* kVersion = "1.0.0";
+#else
+static const char* kVersion = PACKAGE_VERSION;
+#endif
+
+// Global stressapptest reference, for use by signal handler.
+// This makes Sat objects not safe for multiple instances.
+namespace {
+  Sat *g_sat = NULL;
+
+  // Signal handler for catching break or kill.
+  //
+  // This must be installed after g_sat is assigned and while there is a single
+  // thread.
+  //
+  // This must be uninstalled while there is only a single thread, and of course
+  // before g_sat is cleared or deleted.
+  void SatHandleBreak(int signal) {
+    g_sat->Break();
+  }
+}
+
+// Opens the logfile for writing if necessary
+bool Sat::InitializeLogfile() {
+  // Open logfile.
+  if (use_logfile_) {
+    logfile_ = open(logfilename_,
+                    O_WRONLY | O_CREAT | O_DSYNC,
+                    S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+    if (logfile_ < 0) {
+      printf("Fatal Error: cannot open file %s for logging\n",
+             logfilename_);
+      bad_status();
+      return false;
+    }
+    // We seek to the end once instead of opening in append mode because no
+    // other processes should be writing to it while this one exists.
+    if (lseek(logfile_, 0, SEEK_END) == -1) {
+      printf("Fatal Error: cannot seek to end of logfile (%s)\n",
+             logfilename_);
+      bad_status();
+      return false;
+    }
+    Logger::GlobalLogger()->SetLogFd(logfile_);
+  }
+  return true;
+}
+
+// Check that the environment is known and safe to run on.
+// Return 1 if good, 0 if unsuppported.
+bool Sat::CheckEnvironment() {
+  // Check that this is not a debug build. Debug builds lack
+  // enough performance to stress the system.
+#if !defined NDEBUG
+  if (run_on_anything_) {
+    logprintf(1, "Log: Running DEBUG version of SAT, "
+                 "with significantly reduced coverage.\n");
+  } else {
+    logprintf(0, "Process Error: Running DEBUG version of SAT, "
+                 "with significantly reduced coverage.\n");
+    logprintf(0, "Log: Command line option '-A' bypasses this error.\n");
+    bad_status();
+    return false;
+  }
+#elif !defined CHECKOPTS
+  #error Build system regression - COPTS disregarded.
+#endif
+
+  // Use all CPUs if nothing is specified.
+  if (memory_threads_ == -1) {
+    memory_threads_ = os_->num_cpus();
+    logprintf(7, "Log: Defaulting to %d copy threads\n", memory_threads_);
+  }
+
+  // Use all memory if no size is specified.
+  if (size_mb_ == 0)
+    size_mb_ = os_->FindFreeMemSize() / kMegabyte;
+  size_ = static_cast<int64>(size_mb_) * kMegabyte;
+
+  // Autodetect file locations.
+  if (findfiles_ && (file_threads_ == 0)) {
+    // Get a space separated sting of disk locations.
+    list<string> locations = os_->FindFileDevices();
+
+    // Extract each one.
+    while (!locations.empty()) {
+      // Copy and remove the disk name.
+      string disk = locations.back();
+      locations.pop_back();
+
+      logprintf(12, "Log: disk at %s\n", disk.c_str());
+      file_threads_++;
+      filename_.push_back(disk + "/sat_disk.a");
+      file_threads_++;
+      filename_.push_back(disk + "/sat_disk.b");
+    }
+  }
+
+  // We'd better have some memory by this point.
+  if (size_ < 1) {
+    logprintf(0, "Process Error: No memory found to test.\n");
+    bad_status();
+    return false;
+  }
+
+  if (tag_mode_ && ((file_threads_ > 0) ||
+                    (disk_threads_ > 0) ||
+                    (net_threads_ > 0))) {
+    logprintf(0, "Process Error: Memory tag mode incompatible "
+                 "with disk/network DMA.\n");
+    bad_status();
+    return false;
+  }
+
+  // If platform is 32 bit Xeon, floor memory size to multiple of 4.
+  if (address_mode_ == 32) {
+    size_mb_ = (size_mb_ / 4) * 4;
+    size_ = size_mb_ * kMegabyte;
+    logprintf(1, "Log: Flooring memory allocation to multiple of 4: %lldMB\n",
+              size_mb_);
+  }
+
+  // Check if this system is on the whitelist for supported systems.
+  if (!os_->IsSupported()) {
+    if (run_on_anything_) {
+      logprintf(1, "Log: Unsupported system. Running with reduced coverage.\n");
+      // This is ok, continue on.
+    } else {
+      logprintf(0, "Process Error: Unsupported system, "
+                   "no error reporting available\n");
+      logprintf(0, "Log: Command line option '-A' bypasses this error.\n");
+      bad_status();
+      return false;
+    }
+  }
+
+  return true;
+}
+
+// Allocates memory to run the test on
+bool Sat::AllocateMemory() {
+  // Allocate our test memory.
+  bool result = os_->AllocateTestMem(size_, paddr_base_);
+  if (!result) {
+    logprintf(0, "Process Error: failed to allocate memory\n");
+    bad_status();
+    return false;
+  }
+  return true;
+}
+
+// Sets up access to data patterns
+bool Sat::InitializePatterns() {
+  // Initialize pattern data.
+  patternlist_ = new PatternList();
+  if (!patternlist_) {
+    logprintf(0, "Process Error: failed to allocate patterns\n");
+    bad_status();
+    return false;
+  }
+  if (!patternlist_->Initialize()) {
+    logprintf(0, "Process Error: failed to initialize patternlist\n");
+    bad_status();
+    return false;
+  }
+  return true;
+}
+
+// Get any valid page, no tag specified.
+bool Sat::GetValid(struct page_entry *pe) {
+  return GetValid(pe, kDontCareTag);
+}
+
+
+// Fetch and return empty and full pages into the empty and full pools.
+bool Sat::GetValid(struct page_entry *pe, int32 tag) {
+  bool result = false;
+  // Get valid page depending on implementation.
+  if (pe_q_implementation_ == SAT_FINELOCK)
+    result = finelock_q_->GetValid(pe, tag);
+  else if (pe_q_implementation_ == SAT_ONELOCK)
+    result = valid_->PopRandom(pe);
+
+  if (result) {
+    pe->addr = os_->PrepareTestMem(pe->offset, page_length_);  // Map it.
+
+    // Tag this access and current pattern.
+    pe->ts = os_->GetTimestamp();
+    pe->lastpattern = pe->pattern;
+
+    return (pe->addr != 0);     // Return success or failure.
+  }
+  return false;
+}
+
+bool Sat::PutValid(struct page_entry *pe) {
+  if (pe->addr != 0)
+    os_->ReleaseTestMem(pe->addr, pe->offset, page_length_);  // Unmap the page.
+  pe->addr = 0;
+
+  // Put valid page depending on implementation.
+  if (pe_q_implementation_ == SAT_FINELOCK)
+    return finelock_q_->PutValid(pe);
+  else if (pe_q_implementation_ == SAT_ONELOCK)
+    return valid_->Push(pe);
+  else
+    return false;
+}
+
+// Get an empty page with any tag.
+bool Sat::GetEmpty(struct page_entry *pe) {
+  return GetEmpty(pe, kDontCareTag);
+}
+
+bool Sat::GetEmpty(struct page_entry *pe, int32 tag) {
+  bool result = false;
+  // Get empty page depending on implementation.
+  if (pe_q_implementation_ == SAT_FINELOCK)
+    result = finelock_q_->GetEmpty(pe, tag);
+  else if (pe_q_implementation_ == SAT_ONELOCK)
+    result = empty_->PopRandom(pe);
+
+  if (result) {
+    pe->addr = os_->PrepareTestMem(pe->offset, page_length_);  // Map it.
+    return (pe->addr != 0);     // Return success or failure.
+  }
+  return false;
+}
+
+bool Sat::PutEmpty(struct page_entry *pe) {
+  if (pe->addr != 0)
+    os_->ReleaseTestMem(pe->addr, pe->offset, page_length_);  // Unmap the page.
+  pe->addr = 0;
+
+  // Put empty page depending on implementation.
+  if (pe_q_implementation_ == SAT_FINELOCK)
+    return finelock_q_->PutEmpty(pe);
+  else if (pe_q_implementation_ == SAT_ONELOCK)
+    return empty_->Push(pe);
+  else
+    return false;
+}
+
+// Set up the bitmap of physical pages in case we want to see which pages were
+// accessed under this run of SAT.
+void Sat::AddrMapInit() {
+  if (!do_page_map_)
+    return;
+  // Find about how much physical mem is in the system.
+  // TODO(nsanders): Find some way to get the max
+  // and min phys addr in the system.
+  uint64 maxsize = os_->FindFreeMemSize() * 4;
+  sat_assert(maxsize != 0);
+
+  // Make a bitmask of this many pages. Assume that the memory is relatively
+  // zero based. This is true on x86, typically.
+  // This is one bit per page.
+  uint64 arraysize = maxsize / 4096 / 8;
+  unsigned char *bitmap = new unsigned char[arraysize];
+  sat_assert(bitmap);
+
+  // Mark every page as 0, not seen.
+  memset(bitmap, 0, arraysize);
+
+  page_bitmap_size_ = maxsize;
+  page_bitmap_ = bitmap;
+}
+
+// Add the 4k pages in this block to the array of pages SAT has seen.
+void Sat::AddrMapUpdate(struct page_entry *pe) {
+  if (!do_page_map_)
+    return;
+
+  // Go through 4k page blocks.
+  uint64 arraysize = page_bitmap_size_ / 4096 / 8;
+
+  char *base = reinterpret_cast<char*>(pe->addr);
+  for (int i = 0; i < page_length_; i += 4096) {
+    uint64 paddr = os_->VirtualToPhysical(base + i);
+
+    uint32 offset = paddr / 4096 / 8;
+    unsigned char mask = 1 << ((paddr / 4096) % 8);
+
+    if (offset >= arraysize) {
+      logprintf(0, "Process Error: Physical address %#llx is "
+                   "greater than expected %#llx.\n",
+                paddr, page_bitmap_size_);
+      sat_assert(0);
+    }
+    page_bitmap_[offset] |= mask;
+  }
+}
+
+// Print out the physical memory ranges that SAT has accessed.
+void Sat::AddrMapPrint() {
+  if (!do_page_map_)
+    return;
+
+  uint64 pages = page_bitmap_size_ / 4096;
+
+  uint64 last_page = 0;
+  bool valid_range = false;
+
+  logprintf(4, "Log: Printing tested physical ranges.\n");
+
+  for (uint64 i = 0; i < pages; i ++) {
+    int offset = i / 8;
+    unsigned char mask = 1 << (i % 8);
+
+    bool touched = page_bitmap_[offset] & mask;
+    if (touched && !valid_range) {
+      valid_range = true;
+      last_page = i * 4096;
+    } else if (!touched && valid_range) {
+      valid_range = false;
+      logprintf(4, "Log: %#016llx - %#016llx\n", last_page, (i * 4096) - 1);
+    }
+  }
+  logprintf(4, "Log: Done printing physical ranges.\n");
+}
+
+// Initializes page lists and fills pages with data patterns.
+bool Sat::InitializePages() {
+  int result = 1;
+  // Calculate needed page totals.
+  int64 neededpages = memory_threads_ +
+    invert_threads_ +
+    check_threads_ +
+    net_threads_ +
+    file_threads_;
+
+  // Empty-valid page ratio is adjusted depending on queue implementation.
+  // since fine-grain-locked queue keeps both valid and empty entries in the
+  // same queue and randomly traverse to find pages, the empty-valid ratio
+  // should be more even.
+  if (pe_q_implementation_ == SAT_FINELOCK)
+    freepages_ = pages_ / 5 * 2;  // Mark roughly 2/5 of all pages as Empty.
+  else
+    freepages_ = (pages_ / 100) + (2 * neededpages);
+
+  if (freepages_ < neededpages) {
+    logprintf(0, "Process Error: freepages < neededpages.\n");
+    logprintf(1, "Stats: Total: %lld, Needed: %lld, Marked free: %lld\n",
+              static_cast<int64>(pages_),
+              static_cast<int64>(neededpages),
+              static_cast<int64>(freepages_));
+    bad_status();
+    return false;
+  }
+
+  if (freepages_ >  pages_/2) {
+    logprintf(0, "Process Error: not enough pages for IO\n");
+    logprintf(1, "Stats: Total: %lld, Needed: %lld, Available: %lld\n",
+              static_cast<int64>(pages_),
+              static_cast<int64>(freepages_),
+              static_cast<int64>(pages_/2));
+    bad_status();
+    return false;
+  }
+  logprintf(12, "Log: Allocating pages, Total: %lld Free: %lld\n",
+            pages_,
+            freepages_);
+
+  // Initialize page locations.
+  for (int64 i = 0; i < pages_; i++) {
+    struct page_entry pe;
+    init_pe(&pe);
+    pe.offset = i * page_length_;
+    result &= PutEmpty(&pe);
+  }
+
+  if (!result) {
+    logprintf(0, "Process Error: while initializing empty_ list\n");
+    bad_status();
+    return false;
+  }
+
+  // Fill valid pages with test patterns.
+  // Use fill threads to do this.
+  WorkerStatus fill_status;
+  WorkerVector fill_vector;
+
+  logprintf(12, "Starting Fill threads: %d threads, %d pages\n",
+            fill_threads_, pages_);
+  // Initialize the fill threads.
+  for (int i = 0; i < fill_threads_; i++) {
+    FillThread *thread = new FillThread();
+    thread->InitThread(i, this, os_, patternlist_, &fill_status);
+    if (i != fill_threads_ - 1) {
+        logprintf(12, "Starting Fill Threads %d: %d pages\n",
+                  i, pages_ / fill_threads_);
+        thread->SetFillPages(pages_ / fill_threads_);
+      // The last thread finishes up all the leftover pages.
+    } else {
+      logprintf(12, "Starting Fill Threads %d: %d pages\n",
+                i, pages_ - pages_ / fill_threads_ * i);
+        thread->SetFillPages(pages_ - pages_ / fill_threads_ * i);
+    }
+    fill_vector.push_back(thread);
+  }
+
+  // Spawn the fill threads.
+  fill_status.Initialize();
+  for (WorkerVector::const_iterator it = fill_vector.begin();
+       it != fill_vector.end(); ++it)
+    (*it)->SpawnThread();
+
+  // Reap the finished fill threads.
+  for (WorkerVector::const_iterator it = fill_vector.begin();
+       it != fill_vector.end(); ++it) {
+    (*it)->JoinThread();
+    if ((*it)->GetStatus() != 1) {
+      logprintf(0, "Thread %d failed with status %d at %.2f seconds\n",
+                (*it)->ThreadID(), (*it)->GetStatus(),
+                (*it)->GetRunDurationUSec() * 1.0/1000000);
+      bad_status();
+      return false;
+    }
+    delete (*it);
+  }
+  fill_vector.clear();
+  fill_status.Destroy();
+  logprintf(12, "Log: Done filling pages.\n");
+  logprintf(12, "Log: Allocating pages.\n");
+
+  AddrMapInit();
+
+  // Initialize page locations.
+  for (int64 i = 0; i < pages_; i++) {
+    struct page_entry pe;
+    // Only get valid pages with uninitialized tags here.
+    char buf[256];
+    if (GetValid(&pe, kInvalidTag)) {
+      int64 paddr = os_->VirtualToPhysical(pe.addr);
+      int32 region = os_->FindRegion(paddr);
+
+      os_->FindDimm(paddr, buf, sizeof(buf));
+      if (i < 256) {
+        logprintf(12, "Log: address: %#llx, %s\n", paddr, buf);
+      }
+      region_[region]++;
+      pe.paddr = paddr;
+      pe.tag = 1 << region;
+      region_mask_ |= pe.tag;
+
+      // Generate a physical region map
+      AddrMapUpdate(&pe);
+
+      // Note: this does not allocate free pages among all regions
+      // fairly. However, with large enough (thousands) random number
+      // of pages being marked free in each region, the free pages
+      // count in each region end up pretty balanced.
+      if (i < freepages_) {
+        result &= PutEmpty(&pe);
+      } else {
+        result &= PutValid(&pe);
+      }
+    } else {
+      logprintf(0, "Log: didn't tag all pages. %d - %d = %d\n",
+                pages_, i, pages_ - i);
+      return false;
+    }
+  }
+  logprintf(12, "Log: Done allocating pages.\n");
+
+  AddrMapPrint();
+
+  for (int i = 0; i < 32; i++) {
+    if (region_mask_ & (1 << i)) {
+      region_count_++;
+      logprintf(12, "Log: Region %d: %d.\n", i, region_[i]);
+    }
+  }
+  logprintf(5, "Log: Region mask: 0x%x\n", region_mask_);
+
+  return true;
+}
+
+// Print SAT version info.
+bool Sat::PrintVersion() {
+  logprintf(1, "Stats: SAT revision %s, %d bit binary\n",
+            kVersion, address_mode_);
+  logprintf(5, "Log: %s from %s\n", Timestamp(), BuildChangelist());
+
+  return true;
+}
+
+
+// Initializes the resources that SAT needs to run.
+// This needs to be called before Run(), and after ParseArgs().
+// Returns true on success, false on error, and will exit() on help message.
+bool Sat::Initialize() {
+  g_sat = this;
+
+  // Initializes sync'd log file to ensure output is saved.
+  if (!InitializeLogfile())
+    return false;
+  Logger::GlobalLogger()->StartThread();
+
+  logprintf(5, "Log: Commandline - %s\n", cmdline_.c_str());
+  PrintVersion();
+
+  std::map<std::string, std::string> options;
+
+  GoogleOsOptions(&options);
+
+  // Initialize OS/Hardware interface.
+  os_ = OsLayerFactory(options);
+  if (!os_) {
+    bad_status();
+    return false;
+  }
+
+  if (min_hugepages_mbytes_ > 0)
+    os_->SetMinimumHugepagesSize(min_hugepages_mbytes_ * kMegabyte);
+
+  if (!os_->Initialize()) {
+    logprintf(0, "Process Error: Failed to initialize OS layer\n");
+    bad_status();
+    delete os_;
+    return false;
+  }
+
+  // Checks that OS/Build/Platform is supported.
+  if (!CheckEnvironment())
+    return false;
+
+  if (error_injection_)
+    os_->set_error_injection(true);
+
+  // Run SAT in monitor only mode, do not continue to allocate resources.
+  if (monitor_mode_) {
+    logprintf(5, "Log: Running in monitor-only mode. "
+                 "Will not allocate any memory nor run any stress test. "
+                 "Only polling ECC errors.\n");
+    return true;
+  }
+
+  // Allocate the memory to test.
+  if (!AllocateMemory())
+    return false;
+
+  logprintf(5, "Stats: Starting SAT, %dM, %d seconds\n",
+            static_cast<int>(size_/kMegabyte),
+            runtime_seconds_);
+
+  if (!InitializePatterns())
+    return false;
+
+  // Initialize memory allocation.
+  pages_ = size_ / page_length_;
+
+  // Allocate page queue depending on queue implementation switch.
+  if (pe_q_implementation_ == SAT_FINELOCK) {
+      finelock_q_ = new FineLockPEQueue(pages_, page_length_);
+      if (finelock_q_ == NULL)
+        return false;
+      finelock_q_->set_os(os_);
+      os_->set_err_log_callback(finelock_q_->get_err_log_callback());
+  } else if (pe_q_implementation_ == SAT_ONELOCK) {
+      empty_ = new PageEntryQueue(pages_);
+      valid_ = new PageEntryQueue(pages_);
+      if ((empty_ == NULL) || (valid_ == NULL))
+        return false;
+  }
+
+  if (!InitializePages()) {
+    logprintf(0, "Process Error: Initialize Pages failed\n");
+    return false;
+  }
+
+  return true;
+}
+
+// Constructor and destructor.
+Sat::Sat() {
+  // Set defaults, command line might override these.
+  runtime_seconds_ = 20;
+  page_length_ = kSatPageSize;
+  disk_pages_ = kSatDiskPage;
+  pages_ = 0;
+  size_mb_ = 0;
+  size_ = size_mb_ * kMegabyte;
+  min_hugepages_mbytes_ = 0;
+  freepages_ = 0;
+  paddr_base_ = 0;
+
+  user_break_ = false;
+  verbosity_ = 8;
+  Logger::GlobalLogger()->SetVerbosity(verbosity_);
+  strict_ = 1;
+  warm_ = 0;
+  run_on_anything_ = 0;
+  use_logfile_ = 0;
+  logfile_ = 0;
+  // Detect 32/64 bit binary.
+  void *pvoid = 0;
+  address_mode_ = sizeof(pvoid) * 8;
+  error_injection_ = false;
+  crazy_error_injection_ = false;
+  max_errorcount_ = 0;  // Zero means no early exit.
+  stop_on_error_ = false;
+  error_poll_ = true;
+  findfiles_ = false;
+
+  do_page_map_ = false;
+  page_bitmap_ = 0;
+  page_bitmap_size_ = 0;
+
+  // Cache coherency data initialization.
+  cc_test_ = false;         // Flag to trigger cc threads.
+  cc_cacheline_count_ = 2;  // Two datastructures of cache line size.
+  cc_inc_count_ = 1000;     // Number of times to increment the shared variable.
+  cc_cacheline_data_ = 0;   // Cache Line size datastructure.
+
+  sat_assert(0 == pthread_mutex_init(&worker_lock_, NULL));
+  file_threads_ = 0;
+  net_threads_ = 0;
+  listen_threads_ = 0;
+  // Default to autodetect number of cpus, and run that many threads.
+  memory_threads_ = -1;
+  invert_threads_ = 0;
+  fill_threads_ = 8;
+  check_threads_ = 0;
+  cpu_stress_threads_ = 0;
+  disk_threads_ = 0;
+  total_threads_ = 0;
+
+  region_mask_ = 0;
+  region_count_ = 0;
+  for (int i = 0; i < 32; i++) {
+    region_[i] = 0;
+  }
+  region_mode_ = 0;
+
+  errorcount_ = 0;
+  statuscount_ = 0;
+
+  valid_ = 0;
+  empty_ = 0;
+  finelock_q_ = 0;
+  // Default to use fine-grain lock for better performance.
+  pe_q_implementation_ = SAT_FINELOCK;
+
+  os_ = 0;
+  patternlist_ = 0;
+  logfilename_[0] = 0;
+
+  read_block_size_ = 512;
+  write_block_size_ = -1;
+  segment_size_ = -1;
+  cache_size_ = -1;
+  blocks_per_segment_ = -1;
+  read_threshold_ = -1;
+  write_threshold_ = -1;
+  non_destructive_ = 1;
+  monitor_mode_ = 0;
+  tag_mode_ = 0;
+  random_threads_ = 0;
+
+  pause_delay_ = 600;
+  pause_duration_ = 15;
+}
+
+// Destructor.
+Sat::~Sat() {
+  // We need to have called Cleanup() at this point.
+  // We should probably enforce this.
+}
+
+
+#define ARG_KVALUE(argument, variable, value)         \
+  if (!strcmp(argv[i], argument)) {                   \
+    variable = value;                                 \
+    continue;                                         \
+  }
+
+#define ARG_IVALUE(argument, variable)                \
+  if (!strcmp(argv[i], argument)) {                   \
+    i++;                                              \
+    if (i < argc)                                     \
+      variable = strtoull(argv[i], NULL, 0);          \
+    continue;                                         \
+  }
+
+#define ARG_SVALUE(argument, variable)                     \
+  if (!strcmp(argv[i], argument)) {                        \
+    i++;                                                   \
+    if (i < argc)                                          \
+      snprintf(variable, sizeof(variable), "%s", argv[i]); \
+    continue;                                              \
+  }
+
+// Configures SAT from command line arguments.
+// This will call exit() given a request for
+// self-documentation or unexpected args.
+bool Sat::ParseArgs(int argc, char **argv) {
+  int i;
+  uint64 filesize = page_length_ * disk_pages_;
+
+  // Parse each argument.
+  for (i = 1; i < argc; i++) {
+    // Switch to fall back to corase-grain-lock queue. (for benchmarking)
+    ARG_KVALUE("--coarse_grain_lock", pe_q_implementation_, SAT_ONELOCK);
+
+    // Set number of megabyte to use.
+    ARG_IVALUE("-M", size_mb_);
+
+    // Set minimum megabytes of hugepages to require.
+    ARG_IVALUE("-H", min_hugepages_mbytes_);
+
+    // Set number of seconds to run.
+    ARG_IVALUE("-s", runtime_seconds_);
+
+    // Set number of memory copy threads.
+    ARG_IVALUE("-m", memory_threads_);
+
+    // Set number of memory invert threads.
+    ARG_IVALUE("-i", invert_threads_);
+
+    // Set number of check-only threads.
+    ARG_IVALUE("-c", check_threads_);
+
+    // Set number of cache line size datastructures.
+    ARG_IVALUE("--cc_inc_count", cc_inc_count_);
+
+    // Set number of cache line size datastructures
+    ARG_IVALUE("--cc_line_count", cc_cacheline_count_);
+
+    // Flag set when cache coherency tests need to be run
+    ARG_KVALUE("--cc_test", cc_test_, 1);
+
+    // Set number of CPU stress threads.
+    ARG_IVALUE("-C", cpu_stress_threads_);
+
+    // Set logfile name.
+    ARG_SVALUE("-l", logfilename_);
+
+    // Verbosity level.
+    ARG_IVALUE("-v", verbosity_);
+
+    // Set maximum number of errors to collect. Stop running after this many.
+    ARG_IVALUE("--max_errors", max_errorcount_);
+
+    // Set pattern block size.
+    ARG_IVALUE("-p", page_length_);
+
+    // Set pattern block size.
+    ARG_IVALUE("--filesize", filesize);
+
+    // NUMA options.
+    ARG_KVALUE("--local_numa", region_mode_, kLocalNuma);
+    ARG_KVALUE("--remote_numa", region_mode_, kRemoteNuma);
+
+    // Autodetect tempfile locations.
+    ARG_KVALUE("--findfiles", findfiles_, 1);
+
+    // Inject errors to force miscompare code paths
+    ARG_KVALUE("--force_errors", error_injection_, true);
+    ARG_KVALUE("--force_errors_like_crazy", crazy_error_injection_, true);
+    if (crazy_error_injection_)
+      error_injection_ = true;
+
+    // Stop immediately on any arror, for debugging HW problems.
+    ARG_KVALUE("--stop_on_errors", stop_on_error_, 1);
+
+    // Don't use internal error polling, allow external detection.
+    ARG_KVALUE("--no_errors", error_poll_, 0);
+
+    // Never check data as you go.
+    ARG_KVALUE("-F", strict_, 0);
+
+    // Warm the cpu as you go.
+    ARG_KVALUE("-W", warm_, 1);
+
+    // Allow runnign on unknown systems with base unimplemented OsLayer
+    ARG_KVALUE("-A", run_on_anything_, 1);
+
+    // Size of read blocks for disk test.
+    ARG_IVALUE("--read-block-size", read_block_size_);
+
+    // Size of write blocks for disk test.
+    ARG_IVALUE("--write-block-size", write_block_size_);
+
+    // Size of segment for disk test.
+    ARG_IVALUE("--segment-size", segment_size_);
+
+    // Size of disk cache size for disk test.
+    ARG_IVALUE("--cache-size", cache_size_);
+
+    // Number of blocks to test per segment.
+    ARG_IVALUE("--blocks-per-segment", blocks_per_segment_);
+
+    // Maximum time a block read should take before warning.
+    ARG_IVALUE("--read-threshold", read_threshold_);
+
+    // Maximum time a block write should take before warning.
+    ARG_IVALUE("--write-threshold", write_threshold_);
+
+    // Do not write anything to disk in the disk test.
+    ARG_KVALUE("--destructive", non_destructive_, 0);
+
+    // Run SAT in monitor mode. No test load at all.
+    ARG_KVALUE("--monitor_mode", monitor_mode_, true);
+
+    // Run SAT in address mode. Tag all cachelines by virt addr.
+    ARG_KVALUE("--tag_mode", tag_mode_, true);
+
+    // Dump range map of tested pages..
+    ARG_KVALUE("--do_page_map", do_page_map_, true);
+
+    // Specify the physical address base to test.
+    ARG_IVALUE("--paddr_base", paddr_base_);
+
+    // Specify the frequency for power spikes.
+    ARG_IVALUE("--pause_delay", pause_delay_);
+
+    // Specify the duration of each pause (for power spikes).
+    ARG_IVALUE("--pause_duration", pause_duration_);
+
+    // Disk device names
+    if (!strcmp(argv[i], "-d")) {
+      i++;
+      if (i < argc) {
+        disk_threads_++;
+        diskfilename_.push_back(string(argv[i]));
+        blocktables_.push_back(new DiskBlockTable());
+      }
+      continue;
+    }
+
+    // Set number of disk random threads for each disk write thread.
+    ARG_IVALUE("--random-threads", random_threads_);
+
+    // Set a tempfile to use in a file thread.
+    if (!strcmp(argv[i], "-f")) {
+      i++;
+      if (i < argc) {
+        file_threads_++;
+        filename_.push_back(string(argv[i]));
+      }
+      continue;
+    }
+
+    // Set a hostname to use in a network thread.
+    if (!strcmp(argv[i], "-n")) {
+      i++;
+      if (i < argc) {
+        net_threads_++;
+        ipaddrs_.push_back(string(argv[i]));
+      }
+      continue;
+    }
+
+    // Run threads that listen for incoming SAT net connections.
+    ARG_KVALUE("--listen", listen_threads_, 1);
+
+    if (CheckGoogleSpecificArgs(argc, argv, &i)) {
+      continue;
+    }
+
+    // Default:
+    PrintVersion();
+    PrintHelp();
+    if (strcmp(argv[i], "-h") && strcmp(argv[i], "--help")) {
+      printf("\n Unknown argument %s\n", argv[i]);
+      bad_status();
+      exit(1);
+    }
+    // Forget it, we printed the help, just bail.
+    // We don't want to print test status, or any log parser stuff.
+    exit(0);
+  }
+
+  Logger::GlobalLogger()->SetVerbosity(verbosity_);
+
+  // Update relevant data members with parsed input.
+  // Translate MB into bytes.
+  size_ = static_cast<int64>(size_mb_) * kMegabyte;
+
+  // Set logfile flag.
+  if (strcmp(logfilename_, ""))
+    use_logfile_ = 1;
+  // Checks valid page length.
+  if (page_length_ &&
+      !(page_length_ & (page_length_ - 1)) &&
+      (page_length_ > 1023)) {
+    // Prints if we have changed from default.
+    if (page_length_ != kSatPageSize)
+      logprintf(12, "Log: Updating page size to %d\n", page_length_);
+  } else {
+    // Revert to default page length.
+    logprintf(6, "Process Error: "
+              "Invalid page size %d\n", page_length_);
+    page_length_ = kSatPageSize;
+    return false;
+  }
+
+  // Set disk_pages_ if filesize or page size changed.
+  if (filesize != static_cast<uint64>(page_length_) *
+                  static_cast<uint64>(disk_pages_)) {
+    disk_pages_ = filesize / page_length_;
+    if (disk_pages_ == 0)
+      disk_pages_ = 1;
+  }
+
+  // Print each argument.
+  for (int i = 0; i < argc; i++) {
+    if (i)
+      cmdline_ += " ";
+    cmdline_ += argv[i];
+  }
+
+  return true;
+}
+
+void Sat::PrintHelp() {
+  printf("Usage: ./sat(32|64) [options]\n"
+         " -M mbytes        megabytes of ram to test\n"
+         " -H mbytes        minimum megabytes of hugepages to require\n"
+         " -s seconds       number of seconds to run\n"
+         " -m threads       number of memory copy threads to run\n"
+         " -i threads       number of memory invert threads to run\n"
+         " -C threads       number of memory CPU stress threads to run\n"
+         " --findfiles      find locations to do disk IO automatically\n"
+         " -d device        add a direct write disk thread with block "
+         "device (or file) 'device'\n"
+         " -f filename      add a disk thread with "
+         "tempfile 'filename'\n"
+         " -l logfile       log output to file 'logfile'\n"
+         " --max_errors n   exit early after finding 'n' errors\n"
+         " -v level         verbosity (0-20), default is 8\n"
+         " -W               Use more CPU-stressful memory copy\n"
+         " -A               run in degraded mode on incompatible systems\n"
+         " -p pagesize      size in bytes of memory chunks\n"
+         " --filesize size  size of disk IO tempfiles\n"
+         " -n ipaddr        add a network thread connecting to "
+         "system at 'ipaddr'\n"
+         " --listen         run a thread to listen for and respond "
+         "to network threads.\n"
+         " --no_errors      run without checking for ECC or other errors\n"
+         " --force_errors   inject false errors to test error handling\n"
+         " --force_errors_like_crazy   inject a lot of false errors "
+         "to test error handling\n"
+         " -F               don't result check each transaction\n"
+         " --stop_on_errors  Stop after finding the first error.\n"
+         " --read-block-size     size of block for reading (-d)\n"
+         " --write-block-size    size of block for writing (-d). If not "
+         "defined, the size of block for writing will be defined as the "
+         "size of block for reading\n"
+         " --segment-size   size of segments to split disk into (-d)\n"
+         " --cache-size     size of disk cache (-d)\n"
+         " --blocks-per-segment  number of blocks to read/write per "
+         "segment per iteration (-d)\n"
+         " --read-threshold      maximum time (in us) a block read should "
+         "take (-d)\n"
+         " --write-threshold     maximum time (in us) a block write "
+         "should take (-d)\n"
+         " --random-threads      number of random threads for each disk "
+         "write thread (-d)\n"
+         " --destructive    write/wipe disk partition (-d)\n"
+         " --monitor_mode   only do ECC error polling, no stress load.\n"
+         " --cc_test        do the cache coherency testing\n"
+         " --cc_inc_count   number of times to increment the "
+         "cacheline's member\n"
+         " --cc_line_count  number of cache line sized datastructures "
+         "to allocate for the cache coherency threads to operate\n"
+         " --paddr_base     allocate memory starting from this address\n"
+         " --pause_delay    delay (in seconds) between power spikes\n"
+         " --pause_duration duration (in seconds) of each pause\n"
+         " --local_numa : choose memory regions associated with "
+         "each CPU to be tested by that CPU\n"
+         " --remote_numa : choose memory regions not associated with "
+         "each CPU to be tested by that CPU\n");
+}
+
+bool Sat::CheckGoogleSpecificArgs(int argc, char **argv, int *i) {
+  // Do nothing, no google-specific argument on public stressapptest
+  return false;
+}
+
+void Sat::GoogleOsOptions(std::map<std::string, std::string> *options) {
+  // Do nothing, no OS-specific argument on public stressapptest
+}
+
+// Launch the SAT task threads. Returns 0 on error.
+void Sat::InitializeThreads() {
+  // Memory copy threads.
+  AcquireWorkerLock();
+
+  logprintf(12, "Log: Starting worker threads\n");
+  WorkerVector *memory_vector = new WorkerVector();
+
+  // Error polling thread.
+  // This may detect ECC corrected errors, disk problems, or
+  // any other errors normally hidden from userspace.
+  WorkerVector *error_vector = new WorkerVector();
+  if (error_poll_) {
+    ErrorPollThread *thread = new ErrorPollThread();
+    thread->InitThread(total_threads_++, this, os_, patternlist_,
+                       &continuous_status_);
+
+    error_vector->insert(error_vector->end(), thread);
+  } else {
+    logprintf(5, "Log: Skipping error poll thread due to --no_errors flag\n");
+  }
+  workers_map_.insert(make_pair(kErrorType, error_vector));
+
+  // Only start error poll threads for monitor-mode SAT,
+  // skip all other types of worker threads.
+  if (monitor_mode_) {
+    ReleaseWorkerLock();
+    return;
+  }
+
+  for (int i = 0; i < memory_threads_; i++) {
+    CopyThread *thread = new CopyThread();
+    thread->InitThread(total_threads_++, this, os_, patternlist_,
+                       &power_spike_status_);
+
+    if ((region_count_ > 1) && (region_mode_)) {
+      int32 region = region_find(i % region_count_);
+      cpu_set_t *cpuset = os_->FindCoreMask(region);
+      sat_assert(cpuset);
+      if (region_mode_ == kLocalNuma) {
+        // Choose regions associated with this CPU.
+        thread->set_cpu_mask(cpuset);
+        thread->set_tag(1 << region);
+      } else if (region_mode_ == kRemoteNuma) {
+        // Choose regions not associated with this CPU..
+        thread->set_cpu_mask(cpuset);
+        thread->set_tag(region_mask_ & ~(1 << region));
+      }
+    } else {
+      cpu_set_t available_cpus;
+      thread->AvailableCpus(&available_cpus);
+      int cores = cpuset_count(&available_cpus);
+      // Don't restrict thread location if we have more than one
+      // thread per core. Not so good for performance.
+      if (cpu_stress_threads_ + memory_threads_ <= cores) {
+        // Place a thread on alternating cores first.
+        // This assures interleaved core use with no overlap.
+        int nthcore = i;
+        int nthbit = (((2 * nthcore) % cores) +
+                      (((2 * nthcore) / cores) % 2)) % cores;
+        cpu_set_t all_cores;
+        cpuset_set_ab(&all_cores, 0, cores);
+        if (!cpuset_isequal(&available_cpus, &all_cores)) {
+          // We are assuming the bits are contiguous.
+          // Complain if this is not so.
+          logprintf(0, "Log: cores = %s, expected %s\n",
+                    cpuset_format(&available_cpus).c_str(),
+                    cpuset_format(&all_cores).c_str());
+        }
+
+        // Set thread affinity.
+        thread->set_cpu_mask_to_cpu(nthbit);
+      }
+    }
+    memory_vector->insert(memory_vector->end(), thread);
+  }
+  workers_map_.insert(make_pair(kMemoryType, memory_vector));
+
+  // File IO threads.
+  WorkerVector *fileio_vector = new WorkerVector();
+  for (int i = 0; i < file_threads_; i++) {
+    FileThread *thread = new FileThread();
+    thread->InitThread(total_threads_++, this, os_, patternlist_,
+                       &power_spike_status_);
+    thread->SetFile(filename_[i].c_str());
+    // Set disk threads high priority. They don't take much processor time,
+    // but blocking them will delay disk IO.
+    thread->SetPriority(WorkerThread::High);
+
+    fileio_vector->insert(fileio_vector->end(), thread);
+  }
+  workers_map_.insert(make_pair(kFileIOType, fileio_vector));
+
+  // Net IO threads.
+  WorkerVector *netio_vector = new WorkerVector();
+  WorkerVector *netslave_vector = new WorkerVector();
+  if (listen_threads_ > 0) {
+    // Create a network slave thread. This listens for connections.
+    NetworkListenThread *thread = new NetworkListenThread();
+    thread->InitThread(total_threads_++, this, os_, patternlist_,
+                       &continuous_status_);
+
+    netslave_vector->insert(netslave_vector->end(), thread);
+  }
+  for (int i = 0; i < net_threads_; i++) {
+    NetworkThread *thread = new NetworkThread();
+    thread->InitThread(total_threads_++, this, os_, patternlist_,
+                       &continuous_status_);
+    thread->SetIP(ipaddrs_[i].c_str());
+
+    netio_vector->insert(netio_vector->end(), thread);
+  }
+  workers_map_.insert(make_pair(kNetIOType, netio_vector));
+  workers_map_.insert(make_pair(kNetSlaveType, netslave_vector));
+
+  // Result check threads.
+  WorkerVector *check_vector = new WorkerVector();
+  for (int i = 0; i < check_threads_; i++) {
+    CheckThread *thread = new CheckThread();
+    thread->InitThread(total_threads_++, this, os_, patternlist_,
+                       &continuous_status_);
+
+    check_vector->insert(check_vector->end(), thread);
+  }
+  workers_map_.insert(make_pair(kCheckType, check_vector));
+
+  // Memory invert threads.
+  logprintf(12, "Log: Starting invert threads\n");
+  WorkerVector *invert_vector = new WorkerVector();
+  for (int i = 0; i < invert_threads_; i++) {
+    InvertThread *thread = new InvertThread();
+    thread->InitThread(total_threads_++, this, os_, patternlist_,
+                       &continuous_status_);
+
+    invert_vector->insert(invert_vector->end(), thread);
+  }
+  workers_map_.insert(make_pair(kInvertType, invert_vector));
+
+  // Disk stress threads.
+  WorkerVector *disk_vector = new WorkerVector();
+  WorkerVector *random_vector = new WorkerVector();
+  logprintf(12, "Log: Starting disk stress threads\n");
+  for (int i = 0; i < disk_threads_; i++) {
+    // Creating write threads
+    DiskThread *thread = new DiskThread(blocktables_[i]);
+    thread->InitThread(total_threads_++, this, os_, patternlist_,
+                       &power_spike_status_);
+    thread->SetDevice(diskfilename_[i].c_str());
+    if (thread->SetParameters(read_block_size_, write_block_size_,
+                              segment_size_, cache_size_,
+                              blocks_per_segment_,
+                              read_threshold_, write_threshold_,
+                              non_destructive_)) {
+      disk_vector->insert(disk_vector->end(), thread);
+    } else {
+      logprintf(12, "Log: DiskThread::SetParameters() failed\n");
+      delete thread;
+    }
+
+    for (int j = 0; j < random_threads_; j++) {
+      // Creating random threads
+      RandomDiskThread *rthread = new RandomDiskThread(blocktables_[i]);
+      rthread->InitThread(total_threads_++, this, os_, patternlist_,
+                          &power_spike_status_);
+      rthread->SetDevice(diskfilename_[i].c_str());
+      if (rthread->SetParameters(read_block_size_, write_block_size_,
+                                 segment_size_, cache_size_,
+                                 blocks_per_segment_,
+                                 read_threshold_, write_threshold_,
+                                 non_destructive_)) {
+        random_vector->insert(random_vector->end(), rthread);
+      } else {
+      logprintf(12, "Log: RandomDiskThread::SetParameters() failed\n");
+        delete rthread;
+      }
+    }
+  }
+
+  workers_map_.insert(make_pair(kDiskType, disk_vector));
+  workers_map_.insert(make_pair(kRandomDiskType, random_vector));
+
+  // CPU stress threads.
+  WorkerVector *cpu_vector = new WorkerVector();
+  logprintf(12, "Log: Starting cpu stress threads\n");
+  for (int i = 0; i < cpu_stress_threads_; i++) {
+    CpuStressThread *thread = new CpuStressThread();
+    thread->InitThread(total_threads_++, this, os_, patternlist_,
+                       &continuous_status_);
+
+    // Don't restrict thread location if we have more than one
+    // thread per core. Not so good for performance.
+    cpu_set_t available_cpus;
+    thread->AvailableCpus(&available_cpus);
+    int cores = cpuset_count(&available_cpus);
+    if (cpu_stress_threads_ + memory_threads_ <= cores) {
+      // Place a thread on alternating cores first.
+      // Go in reverse order for CPU stress threads. This assures interleaved
+      // core use with no overlap.
+      int nthcore = (cores - 1) - i;
+      int nthbit = (((2 * nthcore) % cores) +
+                    (((2 * nthcore) / cores) % 2)) % cores;
+      cpu_set_t all_cores;
+      cpuset_set_ab(&all_cores, 0, cores);
+      if (!cpuset_isequal(&available_cpus, &all_cores)) {
+        logprintf(0, "Log: cores = %s, expected %s\n",
+                  cpuset_format(&available_cpus).c_str(),
+                  cpuset_format(&all_cores).c_str());
+      }
+
+      // Set thread affinity.
+      thread->set_cpu_mask_to_cpu(nthbit);
+    }
+
+
+    cpu_vector->insert(cpu_vector->end(), thread);
+  }
+  workers_map_.insert(make_pair(kCPUType, cpu_vector));
+
+  // CPU Cache Coherency Threads - one for each core available.
+  if (cc_test_) {
+    WorkerVector *cc_vector = new WorkerVector();
+    logprintf(12, "Log: Starting cpu cache coherency threads\n");
+
+    // Allocate the shared datastructure to be worked on by the threads.
+    cc_cacheline_data_ = reinterpret_cast<cc_cacheline_data*>(
+        malloc(sizeof(cc_cacheline_data) * cc_cacheline_count_));
+    sat_assert(cc_cacheline_data_ != NULL);
+
+    // Initialize the strucutre.
+    memset(cc_cacheline_data_, 0,
+           sizeof(cc_cacheline_data) * cc_cacheline_count_);
+
+    int num_cpus = CpuCount();
+    // Allocate all the nums once so that we get a single chunk
+    // of contiguous memory.
+    int *num;
+    int err_result = posix_memalign(
+        reinterpret_cast<void**>(&num),
+        kCacheLineSize, sizeof(*num) * num_cpus * cc_cacheline_count_);
+    sat_assert(err_result == 0);
+
+    int cline;
+    for (cline = 0; cline < cc_cacheline_count_; cline++) {
+      memset(num, 0, sizeof(num_cpus) * num_cpus);
+      cc_cacheline_data_[cline].num = num;
+      num += num_cpus;
+    }
+
+    int tnum;
+    for (tnum = 0; tnum < num_cpus; tnum++) {
+      CpuCacheCoherencyThread *thread =
+          new CpuCacheCoherencyThread(cc_cacheline_data_, cc_cacheline_count_,
+                                      tnum, cc_inc_count_);
+      thread->InitThread(total_threads_++, this, os_, patternlist_,
+                         &continuous_status_);
+      // Pin the thread to a particular core.
+      thread->set_cpu_mask_to_cpu(tnum);
+
+      // Insert the thread into the vector.
+      cc_vector->insert(cc_vector->end(), thread);
+    }
+    workers_map_.insert(make_pair(kCCType, cc_vector));
+  }
+  ReleaseWorkerLock();
+}
+
+// Return the number of cpus actually present in the machine.
+int Sat::CpuCount() {
+  return sysconf(_SC_NPROCESSORS_CONF);
+}
+
+// Notify and reap worker threads.
+void Sat::JoinThreads() {
+  logprintf(12, "Log: Joining worker threads\n");
+  power_spike_status_.StopWorkers();
+  continuous_status_.StopWorkers();
+
+  AcquireWorkerLock();
+  for (WorkerMap::const_iterator map_it = workers_map_.begin();
+       map_it != workers_map_.end(); ++map_it) {
+    for (WorkerVector::const_iterator it = map_it->second->begin();
+         it != map_it->second->end(); ++it) {
+      logprintf(12, "Log: Joining thread %d\n", (*it)->ThreadID());
+      (*it)->JoinThread();
+    }
+  }
+  ReleaseWorkerLock();
+
+  QueueStats();
+
+  // Finish up result checking.
+  // Spawn 4 check threads to minimize check time.
+  logprintf(12, "Log: Finished countdown, begin to result check\n");
+  WorkerStatus reap_check_status;
+  WorkerVector reap_check_vector;
+
+  // No need for check threads for monitor mode.
+  if (!monitor_mode_) {
+    // Initialize the check threads.
+    for (int i = 0; i < fill_threads_; i++) {
+      CheckThread *thread = new CheckThread();
+      thread->InitThread(total_threads_++, this, os_, patternlist_,
+                         &reap_check_status);
+      logprintf(12, "Log: Finished countdown, begin to result check\n");
+      reap_check_vector.push_back(thread);
+    }
+  }
+
+  reap_check_status.Initialize();
+  // Check threads should be marked to stop ASAP.
+  reap_check_status.StopWorkers();
+
+  // Spawn the check threads.
+  for (WorkerVector::const_iterator it = reap_check_vector.begin();
+       it != reap_check_vector.end(); ++it) {
+    logprintf(12, "Log: Spawning thread %d\n", (*it)->ThreadID());
+    (*it)->SpawnThread();
+  }
+
+  // Join the check threads.
+  for (WorkerVector::const_iterator it = reap_check_vector.begin();
+       it != reap_check_vector.end(); ++it) {
+    logprintf(12, "Log: Joining thread %d\n", (*it)->ThreadID());
+    (*it)->JoinThread();
+  }
+
+  // Reap all children. Stopped threads should have already ended.
+  // Result checking threads will end when they have finished
+  // result checking.
+  logprintf(12, "Log: Join all outstanding threads\n");
+
+  // Find all errors.
+  errorcount_ = GetTotalErrorCount();
+
+  AcquireWorkerLock();
+  for (WorkerMap::const_iterator map_it = workers_map_.begin();
+       map_it != workers_map_.end(); ++map_it) {
+    for (WorkerVector::const_iterator it = map_it->second->begin();
+         it != map_it->second->end(); ++it) {
+      logprintf(12, "Log: Reaping thread status %d\n", (*it)->ThreadID());
+      if ((*it)->GetStatus() != 1) {
+        logprintf(0, "Process Error: Thread %d failed with status %d at "
+                  "%.2f seconds\n",
+                  (*it)->ThreadID(), (*it)->GetStatus(),
+                  (*it)->GetRunDurationUSec()*1.0/1000000);
+        bad_status();
+      }
+      int priority = 12;
+      if ((*it)->GetErrorCount())
+        priority = 5;
+      logprintf(priority, "Log: Thread %d found %lld hardware incidents\n",
+                (*it)->ThreadID(), (*it)->GetErrorCount());
+    }
+  }
+  ReleaseWorkerLock();
+
+
+  // Add in any errors from check threads.
+  for (WorkerVector::const_iterator it = reap_check_vector.begin();
+       it != reap_check_vector.end(); ++it) {
+    logprintf(12, "Log: Reaping thread status %d\n", (*it)->ThreadID());
+    if ((*it)->GetStatus() != 1) {
+      logprintf(0, "Process Error: Thread %d failed with status %d at "
+                "%.2f seconds\n",
+                (*it)->ThreadID(), (*it)->GetStatus(),
+                (*it)->GetRunDurationUSec()*1.0/1000000);
+      bad_status();
+    }
+    errorcount_ += (*it)->GetErrorCount();
+    int priority = 12;
+    if ((*it)->GetErrorCount())
+      priority = 5;
+    logprintf(priority, "Log: Thread %d found %lld hardware incidents\n",
+              (*it)->ThreadID(), (*it)->GetErrorCount());
+    delete (*it);
+  }
+  reap_check_vector.clear();
+  reap_check_status.Destroy();
+}
+
+// Print queuing information.
+void Sat::QueueStats() {
+  finelock_q_->QueueAnalysis();
+}
+
+void Sat::AnalysisAllStats() {
+  float max_runtime_sec = 0.;
+  float total_data = 0.;
+  float total_bandwidth = 0.;
+  float thread_runtime_sec = 0.;
+
+  for (WorkerMap::const_iterator map_it = workers_map_.begin();
+       map_it != workers_map_.end(); ++map_it) {
+    for (WorkerVector::const_iterator it = map_it->second->begin();
+         it != map_it->second->end(); ++it) {
+      thread_runtime_sec = (*it)->GetRunDurationUSec()*1.0/1000000;
+      total_data += (*it)->GetMemoryCopiedData();
+      total_data += (*it)->GetDeviceCopiedData();
+      if (thread_runtime_sec > max_runtime_sec) {
+        max_runtime_sec = thread_runtime_sec;
+      }
+    }
+  }
+
+  total_bandwidth = total_data / max_runtime_sec;
+
+  logprintf(0, "Stats: Completed: %.2fM in %.2fs %.2fMB/s, "
+            "with %d hardware incidents, %d errors\n",
+            total_data,
+            max_runtime_sec,
+            total_bandwidth,
+            errorcount_,
+            statuscount_);
+}
+
+void Sat::MemoryStats() {
+  float memcopy_data = 0.;
+  float memcopy_bandwidth = 0.;
+  WorkerMap::const_iterator mem_it = workers_map_.find(
+      static_cast<int>(kMemoryType));
+  WorkerMap::const_iterator file_it = workers_map_.find(
+      static_cast<int>(kFileIOType));
+  sat_assert(mem_it != workers_map_.end());
+  sat_assert(file_it != workers_map_.end());
+  for (WorkerVector::const_iterator it = mem_it->second->begin();
+       it != mem_it->second->end(); ++it) {
+    memcopy_data += (*it)->GetMemoryCopiedData();
+    memcopy_bandwidth += (*it)->GetMemoryBandwidth();
+  }
+  for (WorkerVector::const_iterator it = file_it->second->begin();
+       it != file_it->second->end(); ++it) {
+    memcopy_data += (*it)->GetMemoryCopiedData();
+    memcopy_bandwidth += (*it)->GetMemoryBandwidth();
+  }
+  GoogleMemoryStats(&memcopy_data, &memcopy_bandwidth);
+  logprintf(4, "Stats: Memory Copy: %.2fM at %.2fMB/s\n",
+            memcopy_data,
+            memcopy_bandwidth);
+}
+
+void Sat::GoogleMemoryStats(float *memcopy_data,
+                            float *memcopy_bandwidth) {
+  // Do nothing, should be implemented by subclasses.
+}
+
+void Sat::FileStats() {
+  float file_data = 0.;
+  float file_bandwidth = 0.;
+  WorkerMap::const_iterator file_it = workers_map_.find(
+      static_cast<int>(kFileIOType));
+  sat_assert(file_it != workers_map_.end());
+  for (WorkerVector::const_iterator it = file_it->second->begin();
+       it != file_it->second->end(); ++it) {
+    file_data += (*it)->GetDeviceCopiedData();
+    file_bandwidth += (*it)->GetDeviceBandwidth();
+  }
+  logprintf(4, "Stats: File Copy: %.2fM at %.2fMB/s\n",
+            file_data,
+            file_bandwidth);
+}
+
+void Sat::CheckStats() {
+  float check_data = 0.;
+  float check_bandwidth = 0.;
+  WorkerMap::const_iterator check_it = workers_map_.find(
+      static_cast<int>(kCheckType));
+  sat_assert(check_it != workers_map_.end());
+  for (WorkerVector::const_iterator it = check_it->second->begin();
+       it != check_it->second->end(); ++it) {
+    check_data += (*it)->GetMemoryCopiedData();
+    check_bandwidth += (*it)->GetMemoryBandwidth();
+  }
+  logprintf(4, "Stats: Data Check: %.2fM at %.2fMB/s\n",
+            check_data,
+            check_bandwidth);
+}
+
+void Sat::NetStats() {
+  float net_data = 0.;
+  float net_bandwidth = 0.;
+  WorkerMap::const_iterator netio_it = workers_map_.find(
+      static_cast<int>(kNetIOType));
+  WorkerMap::const_iterator netslave_it = workers_map_.find(
+      static_cast<int>(kNetSlaveType));
+  sat_assert(netio_it != workers_map_.end());
+  sat_assert(netslave_it != workers_map_.end());
+  for (WorkerVector::const_iterator it = netio_it->second->begin();
+       it != netio_it->second->end(); ++it) {
+    net_data += (*it)->GetDeviceCopiedData();
+    net_bandwidth += (*it)->GetDeviceBandwidth();
+  }
+  for (WorkerVector::const_iterator it = netslave_it->second->begin();
+       it != netslave_it->second->end(); ++it) {
+    net_data += (*it)->GetDeviceCopiedData();
+    net_bandwidth += (*it)->GetDeviceBandwidth();
+  }
+  logprintf(4, "Stats: Net Copy: %.2fM at %.2fMB/s\n",
+            net_data,
+            net_bandwidth);
+}
+
+void Sat::InvertStats() {
+  float invert_data = 0.;
+  float invert_bandwidth = 0.;
+  WorkerMap::const_iterator invert_it = workers_map_.find(
+      static_cast<int>(kInvertType));
+  sat_assert(invert_it != workers_map_.end());
+  for (WorkerVector::const_iterator it = invert_it->second->begin();
+       it != invert_it->second->end(); ++it) {
+    invert_data += (*it)->GetMemoryCopiedData();
+    invert_bandwidth += (*it)->GetMemoryBandwidth();
+  }
+  logprintf(4, "Stats: Invert Data: %.2fM at %.2fMB/s\n",
+            invert_data,
+            invert_bandwidth);
+}
+
+void Sat::DiskStats() {
+  float disk_data = 0.;
+  float disk_bandwidth = 0.;
+  WorkerMap::const_iterator disk_it = workers_map_.find(
+      static_cast<int>(kDiskType));
+  WorkerMap::const_iterator random_it = workers_map_.find(
+      static_cast<int>(kRandomDiskType));
+  sat_assert(disk_it != workers_map_.end());
+  sat_assert(random_it != workers_map_.end());
+  for (WorkerVector::const_iterator it = disk_it->second->begin();
+       it != disk_it->second->end(); ++it) {
+    disk_data += (*it)->GetDeviceCopiedData();
+    disk_bandwidth += (*it)->GetDeviceBandwidth();
+  }
+  for (WorkerVector::const_iterator it = random_it->second->begin();
+       it != random_it->second->end(); ++it) {
+    disk_data += (*it)->GetDeviceCopiedData();
+    disk_bandwidth += (*it)->GetDeviceBandwidth();
+  }
+
+  logprintf(4, "Stats: Disk: %.2fM at %.2fMB/s\n",
+            disk_data,
+            disk_bandwidth);
+}
+
+// Process worker thread data for bandwidth information, and error results.
+// You can add more methods here just subclassing SAT.
+void Sat::RunAnalysis() {
+  AnalysisAllStats();
+  MemoryStats();
+  FileStats();
+  NetStats();
+  CheckStats();
+  InvertStats();
+  DiskStats();
+}
+
+// Get total error count, summing across all threads..
+int64 Sat::GetTotalErrorCount() {
+  int64 errors = 0;
+
+  AcquireWorkerLock();
+  for (WorkerMap::const_iterator map_it = workers_map_.begin();
+       map_it != workers_map_.end(); ++map_it) {
+    for (WorkerVector::const_iterator it = map_it->second->begin();
+         it != map_it->second->end(); ++it) {
+      errors += (*it)->GetErrorCount();
+    }
+  }
+  ReleaseWorkerLock();
+  return errors;
+}
+
+
+void Sat::SpawnThreads() {
+  logprintf(12, "Log: Initializing WorkerStatus objects\n");
+  power_spike_status_.Initialize();
+  continuous_status_.Initialize();
+  logprintf(12, "Log: Spawning worker threads\n");
+  for (WorkerMap::const_iterator map_it = workers_map_.begin();
+       map_it != workers_map_.end(); ++map_it) {
+    for (WorkerVector::const_iterator it = map_it->second->begin();
+         it != map_it->second->end(); ++it) {
+      logprintf(12, "Log: Spawning thread %d\n", (*it)->ThreadID());
+      (*it)->SpawnThread();
+    }
+  }
+}
+
+// Delete used worker thread objects.
+void Sat::DeleteThreads() {
+  logprintf(12, "Log: Deleting worker threads\n");
+  for (WorkerMap::const_iterator map_it = workers_map_.begin();
+       map_it != workers_map_.end(); ++map_it) {
+    for (WorkerVector::const_iterator it = map_it->second->begin();
+         it != map_it->second->end(); ++it) {
+      logprintf(12, "Log: Deleting thread %d\n", (*it)->ThreadID());
+      delete (*it);
+    }
+    delete map_it->second;
+  }
+  workers_map_.clear();
+  logprintf(12, "Log: Destroying WorkerStatus objects\n");
+  power_spike_status_.Destroy();
+  continuous_status_.Destroy();
+}
+
+namespace {
+// Calculates the next time an action in Sat::Run() should occur, based on a
+// schedule derived from a start point and a regular frequency.
+//
+// Using frequencies instead of intervals with their accompanying drift allows
+// users to better predict when the actions will occur throughout a run.
+//
+// Arguments:
+//   frequency: seconds
+//   start: unixtime
+//   now: unixtime
+//
+// Returns: unixtime
+inline time_t NextOccurance(time_t frequency, time_t start, time_t now) {
+  return start + frequency + (((now - start) / frequency) * frequency);
+}
+}
+
+// Run the actual test.
+bool Sat::Run() {
+  // Install signal handlers to gracefully exit in the middle of a run.
+  //
+  // Why go through this whole rigmarole?  It's the only standards-compliant
+  // (C++ and POSIX) way to handle signals in a multithreaded program.
+  // Specifically:
+  //
+  // 1) (C++) The value of a variable not of type "volatile sig_atomic_t" is
+  //    unspecified upon entering a signal handler and, if modified by the
+  //    handler, is unspecified after leaving the handler.
+  //
+  // 2) (POSIX) After the value of a variable is changed in one thread, another
+  //    thread is only guaranteed to see the new value after both threads have
+  //    acquired or released the same mutex or rwlock, synchronized to the
+  //    same barrier, or similar.
+  //
+  // #1 prevents the use of #2 in a signal handler, so the signal handler must
+  // be called in the same thread that reads the "volatile sig_atomic_t"
+  // variable it sets.  We enforce that by blocking the signals in question in
+  // the worker threads, forcing them to be handled by this thread.
+  logprintf(12, "Log: Installing signal handlers\n");
+  sigset_t new_blocked_signals;
+  sigemptyset(&new_blocked_signals);
+  sigaddset(&new_blocked_signals, SIGINT);
+  sigaddset(&new_blocked_signals, SIGTERM);
+  sigset_t prev_blocked_signals;
+  pthread_sigmask(SIG_BLOCK, &new_blocked_signals, &prev_blocked_signals);
+  sighandler_t prev_sigint_handler = signal(SIGINT, SatHandleBreak);
+  sighandler_t prev_sigterm_handler = signal(SIGTERM, SatHandleBreak);
+
+  // Kick off all the worker threads.
+  logprintf(12, "Log: Launching worker threads\n");
+  InitializeThreads();
+  SpawnThreads();
+  pthread_sigmask(SIG_SETMASK, &prev_blocked_signals, NULL);
+
+  logprintf(12, "Log: Starting countdown with %d seconds\n", runtime_seconds_);
+
+  // In seconds.
+  static const time_t kSleepFrequency = 5;
+  // All of these are in seconds.  You probably want them to be >=
+  // kSleepFrequency and multiples of kSleepFrequency, but neither is necessary.
+  static const time_t kInjectionFrequency = 10;
+  static const time_t kPrintFrequency = 10;
+
+  const time_t start = time(NULL);
+  const time_t end = start + runtime_seconds_;
+  time_t now = start;
+  time_t next_print = start + kPrintFrequency;
+  time_t next_pause = start + pause_delay_;
+  time_t next_resume = 0;
+  time_t next_injection;
+  if (crazy_error_injection_) {
+    next_injection = start + kInjectionFrequency;
+  } else {
+    next_injection = 0;
+  }
+
+  while (now < end) {
+    // This is an int because it's for logprintf().
+    const int seconds_remaining = end - now;
+
+    if (user_break_) {
+      // Handle early exit.
+      logprintf(0, "Log: User exiting early (%d seconds remaining)\n",
+                seconds_remaining);
+      break;
+    }
+
+    // If we have an error limit, check it here and see if we should exit.
+    if (max_errorcount_ != 0) {
+      uint64 errors = GetTotalErrorCount();
+      if (errors > max_errorcount_) {
+        logprintf(0, "Log: Exiting early (%d seconds remaining) "
+                     "due to excessive failures (%lld)\n",
+                  seconds_remaining,
+                  errors);
+        break;
+      }
+    }
+
+    if (now >= next_print) {
+      // Print a count down message.
+      logprintf(5, "Log: Seconds remaining: %d\n", seconds_remaining);
+      next_print = NextOccurance(kPrintFrequency, start, now);
+    }
+
+    if (next_injection && now >= next_injection) {
+      // Inject an error.
+      logprintf(4, "Log: Injecting error (%d seconds remaining)\n",
+                seconds_remaining);
+      struct page_entry src;
+      GetValid(&src);
+      src.pattern = patternlist_->GetPattern(0);
+      PutValid(&src);
+      next_injection = NextOccurance(kInjectionFrequency, start, now);
+    }
+
+    if (next_pause && now >= next_pause) {
+      // Tell worker threads to pause in preparation for a power spike.
+      logprintf(4, "Log: Pausing worker threads in preparation for power spike "
+                "(%d seconds remaining)\n", seconds_remaining);
+      power_spike_status_.PauseWorkers();
+      logprintf(12, "Log: Worker threads paused\n");
+      next_pause = 0;
+      next_resume = now + pause_duration_;
+    }
+
+    if (next_resume && now >= next_resume) {
+      // Tell worker threads to resume in order to cause a power spike.
+      logprintf(4, "Log: Resuming worker threads to cause a power spike (%d "
+                "seconds remaining)\n", seconds_remaining);
+      power_spike_status_.ResumeWorkers();
+      logprintf(12, "Log: Worker threads resumed\n");
+      next_pause = NextOccurance(pause_delay_, start, now);
+      next_resume = 0;
+    }
+
+    sat_sleep(NextOccurance(kSleepFrequency, start, now) - now);
+    now = time(NULL);
+  }
+
+  JoinThreads();
+
+  logprintf(0, "Stats: Found %lld hardware incidents\n", errorcount_);
+
+  if (!monitor_mode_)
+    RunAnalysis();
+
+  DeleteThreads();
+
+  logprintf(12, "Log: Uninstalling signal handlers\n");
+  signal(SIGINT, prev_sigint_handler);
+  signal(SIGTERM, prev_sigterm_handler);
+
+  return true;
+}
+
+// Clean up all resources.
+bool Sat::Cleanup() {
+  g_sat = NULL;
+  Logger::GlobalLogger()->StopThread();
+  Logger::GlobalLogger()->SetStdoutOnly();
+  if (logfile_) {
+    close(logfile_);
+    logfile_ = 0;
+  }
+  if (patternlist_) {
+    patternlist_->Destroy();
+    delete patternlist_;
+    patternlist_ = 0;
+  }
+  if (os_) {
+    os_->FreeTestMem();
+    delete os_;
+    os_ = 0;
+  }
+  if (empty_) {
+    delete empty_;
+    empty_ = 0;
+  }
+  if (valid_) {
+    delete valid_;
+    valid_ = 0;
+  }
+  if (finelock_q_) {
+    delete finelock_q_;
+    finelock_q_ = 0;
+  }
+  if (page_bitmap_) {
+    delete[] page_bitmap_;
+  }
+
+  for (size_t i = 0; i < blocktables_.size(); i++) {
+    delete blocktables_[i];
+  }
+
+  if (cc_cacheline_data_) {
+    // The num integer arrays for all the cacheline structures are
+    // allocated as a single chunk. The pointers in the cacheline struct
+    // are populated accordingly. Hence calling free on the first
+    // cacheline's num's address is going to free the entire array.
+    // TODO(aganti): Refactor this to have a class for the cacheline
+    // structure (currently defined in worker.h) and clean this up
+    // in the destructor of that class.
+    if (cc_cacheline_data_[0].num) {
+      free(cc_cacheline_data_[0].num);
+    }
+    free(cc_cacheline_data_);
+  }
+
+  sat_assert(0 == pthread_mutex_destroy(&worker_lock_));
+
+  return true;
+}
+
+
+// Pretty print really obvious results.
+bool Sat::PrintResults() {
+  bool result = true;
+
+  logprintf(4, "\n");
+  if (statuscount_) {
+    logprintf(4, "Status: FAIL - test encountered procedural errors\n");
+    result = false;
+  } else if (errorcount_) {
+    logprintf(4, "Status: FAIL - test discovered HW problems\n");
+    result = false;
+  } else {
+    logprintf(4, "Status: PASS - please verify no corrected errors\n");
+  }
+  logprintf(4, "\n");
+
+  return result;
+}
+
+// Helper functions.
+void Sat::AcquireWorkerLock() {
+  sat_assert(0 == pthread_mutex_lock(&worker_lock_));
+}
+void Sat::ReleaseWorkerLock() {
+  sat_assert(0 == pthread_mutex_unlock(&worker_lock_));
+}
+
+void logprintf(int priority, const char *format, ...) {
+  va_list args;
+  va_start(args, format);
+  Logger::GlobalLogger()->VLogF(priority, format, args);
+  va_end(args);
+}
diff --git a/src/sat.h b/src/sat.h
new file mode 100644
index 0000000..b48f519
--- /dev/null
+++ b/src/sat.h
@@ -0,0 +1,310 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// sat.h : sat stress test object interface and data structures
+
+#ifndef STRESSAPPTEST_SAT_H_
+#define STRESSAPPTEST_SAT_H_
+
+#include <signal.h>
+
+#include <map>
+#include <string>
+#include <vector>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "finelock_queue.h"
+#include "queue.h"
+#include "sattypes.h"
+#include "worker.h"
+#include "os.h"
+
+// SAT stress test class.
+class Sat {
+ public:
+  // Enum for page queue implementation switch.
+  enum PageQueueType { SAT_ONELOCK, SAT_FINELOCK };
+
+  Sat();
+  virtual ~Sat();
+
+  // Read configuration from arguments. Called first.
+  bool ParseArgs(int argc, char **argv);
+  virtual bool CheckGoogleSpecificArgs(int argc, char **argv, int *i);
+  // Initialize data structures, subclasses, and resources,
+  // based on command line args.
+  // Called after ParseArgs().
+  bool Initialize();
+
+  // Execute the test. Initialize() and ParseArgs() must be called first.
+  // This must be called from a single-threaded program.
+  bool Run();
+
+  // Pretty print result summary.
+  // Called after Run().
+  // Return value is success or failure of the SAT run, *not* of this function!
+  bool PrintResults();
+
+  // Pretty print version info.
+  bool PrintVersion();
+
+  // Pretty print help.
+  virtual void PrintHelp();
+
+  // Clean up allocations and resources.
+  // Called last.
+  bool Cleanup();
+
+  // Abort Run().  Only for use by Run()-installed signal handlers.
+  void Break() { user_break_ = true; }
+
+  // Fetch and return empty and full pages into the empty and full pools.
+  bool GetValid(struct page_entry *pe);
+  bool PutValid(struct page_entry *pe);
+  bool GetEmpty(struct page_entry *pe);
+  bool PutEmpty(struct page_entry *pe);
+
+  bool GetValid(struct page_entry *pe, int32 tag);
+  bool GetEmpty(struct page_entry *pe, int32 tag);
+
+  // Accessor functions.
+  int verbosity() const { return verbosity_; }
+  int logfile() const { return logfile_; }
+  int page_length() const { return page_length_; }
+  int disk_pages() const { return disk_pages_; }
+  int strict() const { return strict_; }
+  int tag_mode() const { return tag_mode_; }
+  int status() const { return statuscount_; }
+  void bad_status() { statuscount_++; }
+  int errors() const { return errorcount_; }
+  int warm() const { return warm_; }
+  bool stop_on_error() const { return stop_on_error_; }
+  int32 region_mask() const { return region_mask_; }
+  // Semi-accessor to find the "nth" region to avoid replicated bit searching..
+  int32 region_find(int32 num) const {
+    for (int i = 0; i < 32; i++) {
+      if ((1 << i) & region_mask_) {
+        if (num == 0)
+          return i;
+        num--;
+      }
+    }
+    return 0;
+  }
+
+  // Causes false errors for unittesting.
+  // Setting to "true" causes errors to be injected.
+  void set_error_injection(bool errors) { error_injection_ = errors; }
+  bool error_injection() const { return error_injection_; }
+
+ protected:
+  // Opens log file for writing. Returns 0 on failure.
+  bool InitializeLogfile();
+  // Checks for supported environment. Returns 0 on failure.
+  bool CheckEnvironment();
+  // Allocates size_ bytes of test memory.
+  bool AllocateMemory();
+  // Initializes datapattern reference structures.
+  bool InitializePatterns();
+  // Initializes test memory with datapatterns.
+  bool InitializePages();
+
+  // Start up worker threads.
+  virtual void InitializeThreads();
+  // Spawn worker threads.
+  void SpawnThreads();
+  // Reap worker threads.
+  void JoinThreads();
+  // Run bandwidth and error analysis.
+  virtual void RunAnalysis();
+  // Delete worker threads.
+  void DeleteThreads();
+
+  // Return the number of cpus in the system.
+  int CpuCount();
+
+  // Collect error counts from threads.
+  int64 GetTotalErrorCount();
+
+  // Command line arguments.
+  string cmdline_;
+
+  // Memory and test configuration.
+  int runtime_seconds_;               // Seconds to run.
+  int page_length_;                   // Length of each memory block.
+  int64 pages_;                       // Number of memory blocks.
+  int64 size_;                        // Size of memory tested, in bytes.
+  int64 size_mb_;                     // Size of memory tested, in MB.
+  int64 min_hugepages_mbytes_;        // Minimum hugepages size.
+  int64 freepages_;                   // How many invalid pages we need.
+  int disk_pages_;                    // Number of pages per temp file.
+  uint64 paddr_base_;                 // Physical address base.
+
+  // Control flags.
+  volatile sig_atomic_t user_break_;  // User has signalled early exit.  Used as
+                                      // a boolean.
+  int verbosity_;                     // How much to print.
+  int strict_;                        // Check results per transaction.
+  int warm_;                          // FPU warms CPU while coying.
+  int address_mode_;                  // 32 or 64 bit binary.
+  bool stop_on_error_;                // Exit immendiately on any error.
+  bool findfiles_;                    // Autodetect tempfile locations.
+
+  bool error_injection_;              // Simulate errors, for unittests.
+  bool crazy_error_injection_;        // Simulate lots of errors.
+  uint64 max_errorcount_;             // Number of errors before forced exit.
+  int run_on_anything_;               // Ignore unknown machine ereor.
+  int use_logfile_;                   // Log to a file.
+  char logfilename_[255];             // Name of file to log to.
+  int logfile_;                       // File handle to log to.
+
+  // Disk thread options.
+  int read_block_size_;               // Size of block to read from disk.
+  int write_block_size_;              // Size of block to write to disk.
+  int64 segment_size_;                // Size of segment to split disk into.
+  int cache_size_;                    // Size of disk cache.
+  int blocks_per_segment_;            // Number of blocks to test per segment.
+  int read_threshold_;                // Maximum time (in us) a read should take
+                                      // before warning of a slow read.
+  int write_threshold_;               // Maximum time (in us) a write should
+                                      // take before warning of a slow write.
+  int non_destructive_;               // Whether to use non-destructive mode for
+                                      // the disk test.
+
+  // Generic Options.
+  int monitor_mode_;                  // Switch for monitor-only mode SAT.
+                                      // This switch trumps most of the other
+                                      // argument, as SAT will only run error
+                                      // polling threads.
+  int tag_mode_;                      // Do tagging of memory and strict
+                                      // checking for misplaced cachelines.
+
+  bool do_page_map_;                  // Should we print a list of used pages?
+  unsigned char *page_bitmap_;        // Store bitmap of physical pages seen.
+  uint64 page_bitmap_size_;           // Length of physical memory represented.
+
+  // Cpu Cache Coherency Options.
+  bool cc_test_;                      // Flag to decide whether to start the
+                                      // cache coherency threads.
+  int cc_cacheline_count_;            // Number of cache line size structures.
+  int cc_inc_count_;                  // Number of times to increment the shared
+                                      // cache lines structure members.
+
+  // Thread control.
+  int file_threads_;                  // Threads of file IO.
+  int net_threads_;                   // Threads of network IO.
+  int listen_threads_;                // Threads for network IO to connect.
+  int memory_threads_;                // Threads of memcpy.
+  int invert_threads_;                // Threads of invert.
+  int fill_threads_;                  // Threads of memset.
+  int check_threads_;                 // Threads of strcmp.
+  int cpu_stress_threads_;            // Threads of CPU stress workload.
+  int disk_threads_;                  // Threads of disk test.
+  int random_threads_;                // Number of random disk threads.
+  int total_threads_;                 // Total threads used.
+  bool error_poll_;                   // Poll for system errors.
+
+  // Resources.
+  cc_cacheline_data *cc_cacheline_data_;  // The cache line sized datastructure
+                                          // used by the ccache threads
+                                          // (in worker.h).
+  vector<string> filename_;           // Filenames for file IO.
+  vector<string> ipaddrs_;            // Addresses for network IO.
+  vector<string> diskfilename_;       // Filename for disk IO device.
+  // Block table for IO device.
+  vector<DiskBlockTable*> blocktables_;
+
+  int32 region_mask_;                 // Bitmask of available NUMA regions.
+  int32 region_count_;                // Count of available NUMA regions.
+  int32 region_[32];                  // Pagecount per region.
+  int region_mode_;                   // What to do with NUMA hints?
+  static const int kLocalNuma = 1;    // Target local memory.
+  static const int kRemoteNuma = 2;   // Target remote memory.
+
+  // Results.
+  int64 errorcount_;                  // Total hardware incidents seen.
+  int statuscount_;                   // Total test errors seen.
+
+  // Thread type constants and types
+  enum ThreadType {
+    kMemoryType = 0,
+    kFileIOType = 1,
+    kNetIOType = 2,
+    kNetSlaveType = 3,
+    kCheckType = 4,
+    kInvertType = 5,
+    kDiskType = 6,
+    kRandomDiskType = 7,
+    kCPUType = 8,
+    kErrorType = 9,
+    kCCType = 10
+  };
+
+  // Helper functions.
+  virtual void AcquireWorkerLock();
+  virtual void ReleaseWorkerLock();
+  pthread_mutex_t worker_lock_;  // Lock access to the worker thread structure.
+  typedef vector<WorkerThread*> WorkerVector;
+  typedef map<int, WorkerVector*> WorkerMap;
+  // Contains all worker threads.
+  WorkerMap workers_map_;
+  // Delay between power spikes.
+  time_t pause_delay_;
+  // The duration of each pause (for power spikes).
+  time_t pause_duration_;
+  // For the workers we pause and resume to create power spikes.
+  WorkerStatus power_spike_status_;
+  // For the workers we never pause.
+  WorkerStatus continuous_status_;
+
+  class OsLayer *os_;                   // Os abstraction: put hacks here.
+  class PatternList *patternlist_;      // Access to global data patterns.
+
+  // RunAnalysis methods
+  void AnalysisAllStats();              // Summary of all runs.
+  void MemoryStats();
+  void FileStats();
+  void NetStats();
+  void CheckStats();
+  void InvertStats();
+  void DiskStats();
+
+  void QueueStats();
+
+  // Physical page use reporting.
+  void AddrMapInit();
+  void AddrMapUpdate(struct page_entry *pe);
+  void AddrMapPrint();
+
+  // additional memory data from google-specific tests.
+  virtual void GoogleMemoryStats(float *memcopy_data,
+                                 float *memcopy_bandwidth);
+
+  virtual void GoogleOsOptions(std::map<std::string, std::string> *options);
+
+  // Page queues, only one of (valid_+empty_) or (finelock_q_) will be used
+  // at a time. A commandline switch controls which queue implementation will
+  // be used.
+  class PageEntryQueue *valid_;        // Page queue structure, valid pages.
+  class PageEntryQueue *empty_;        // Page queue structure, free pages.
+  class FineLockPEQueue *finelock_q_;  // Page queue with fine-grain locks
+  Sat::PageQueueType pe_q_implementation_;   // Queue implementation switch
+
+  DISALLOW_COPY_AND_ASSIGN(Sat);
+};
+
+Sat *SatFactory();
+
+#endif  // STRESSAPPTEST_SAT_H_
diff --git a/src/sat_factory.cc b/src/sat_factory.cc
new file mode 100644
index 0000000..5cf3e4c
--- /dev/null
+++ b/src/sat_factory.cc
@@ -0,0 +1,21 @@
+// Copyright 2008 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// sat_factory.h : factory for SAT
+
+#include "sat.h"  // NOLINT
+
+Sat *SatFactory() {
+  return new Sat();
+}
diff --git a/src/sattypes.h b/src/sattypes.h
new file mode 100644
index 0000000..96bf13b
--- /dev/null
+++ b/src/sattypes.h
@@ -0,0 +1,187 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef STRESSAPPTEST_SATTYPES_H_
+#define STRESSAPPTEST_SATTYPES_H_
+
+#include <arpa/inet.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <time.h>
+#include <string.h>
+#include <algorithm>
+#include <string>
+
+#ifdef HAVE_CONFIG_H  // Built using autoconf
+#include "stressapptest_config.h"
+using namespace std;
+using namespace __gnu_cxx;
+
+typedef signed long long   int64;
+typedef signed int         int32;
+typedef signed short int   int16;
+typedef signed char        int8;
+
+typedef unsigned long long uint64;
+typedef unsigned int       uint32;
+typedef unsigned short     uint16;
+typedef unsigned char      uint8;
+
+#define DISALLOW_COPY_AND_ASSIGN(TypeName)        \
+  TypeName(const TypeName&);                      \
+  void operator=(const TypeName&)
+
+inline const char* Timestamp() {
+  return STRESSAPPTEST_TIMESTAMP;
+}
+
+inline const char* BuildChangelist() {
+  return "open source release";
+}
+
+static const bool kOpenSource = true;
+#else
+static const bool kOpenSource = false;
+  #include "googlesattypes.h"
+#endif
+// Workaround to allow 32/64 bit conversion
+// without running into strict aliasing problems.
+union datacast_t {
+  uint64 l64;
+  struct {
+    uint32 l;
+    uint32 h;
+  } l32;
+};
+
+
+// File sync'd print to console and log
+void logprintf(int priority, const char *format, ...);
+
+// We print to stderr ourselves first in case we're in such a bad state that the
+// logger can't work.
+#define sat_assert(x) \
+{\
+  if (!(x)) {\
+    fprintf(stderr, "Assertion failed at %s:%d\n", __FILE__, __LINE__);\
+    logprintf(0, "Assertion failed at %s:%d\n", __FILE__, __LINE__);\
+    exit(1);\
+  }\
+}
+
+#if !defined(CPU_SETSIZE)
+  // Define type and macros for cpu mask operations
+  // Note: this code is hacked together to deal with difference
+  // function signatures across versions of glibc, ie those that take
+  // cpu_set_t versus those that take unsigned long.  -johnhuang
+  typedef uint64 cpu_set_t;
+  #define CPU_SETSIZE                   (sizeof(cpu_set_t) * 8)
+  #define CPU_ISSET(index, cpu_set_ptr) (*(cpu_set_ptr) & 1ull << (index))
+  #define CPU_SET(index, cpu_set_ptr)   (*(cpu_set_ptr) |= 1ull << (index))
+  #define CPU_ZERO(cpu_set_ptr)         (*(cpu_set_ptr) = 0)
+  #define CPU_CLR(index, cpu_set_ptr)   (*(cpu_set_ptr) &= ~(1ull << (index)))
+#endif
+
+static inline bool cpuset_isequal(const cpu_set_t *c1, const cpu_set_t *c2) {
+  for (int i = 0; i < CPU_SETSIZE; ++i)
+    if ((CPU_ISSET(i, c1) != 0) != (CPU_ISSET(i, c2) != 0))
+      return false;
+  return true;
+}
+
+static inline bool cpuset_issubset(const cpu_set_t *c1, const cpu_set_t *c2) {
+  for (int i = 0; i < CPU_SETSIZE; ++i)
+    if (CPU_ISSET(i, c1) && !CPU_ISSET(i, c2))
+      return false;
+  return true;
+}
+
+static inline int cpuset_count(const cpu_set_t *cpuset) {
+  int count = 0;
+  for (int i = 0; i < CPU_SETSIZE; ++i)
+    if (CPU_ISSET(i, cpuset))
+      ++count;
+  return count;
+}
+
+static inline void cpuset_set_ab(cpu_set_t *cpuset, int a, int b) {
+  CPU_ZERO(cpuset);
+  for (int i = a; i < b; ++i)
+    CPU_SET(i, cpuset);
+}
+
+static inline string cpuset_format(const cpu_set_t *cpuset) {
+  string format;
+  int digit = 0, last_non_zero_size = 1;
+  for (int i = 0; i < CPU_SETSIZE; ++i) {
+    if (CPU_ISSET(i, cpuset)) {
+      digit |= 1 << (i & 3);
+    }
+    if ((i & 3) == 3) {
+      format += char(digit <= 9 ? '0' + digit: 'A' + digit - 10);
+      if (digit) {
+        last_non_zero_size = format.size();
+        digit = 0;
+      }
+    }
+  }
+  if (digit) {
+    format += char(digit <= 9 ? '0' + digit: 'A' + digit - 10);
+    last_non_zero_size = format.size();
+  }
+  format.erase(last_non_zero_size);
+  reverse(format.begin(), format.end());
+  return format;
+}
+
+static const int32 kUSleepOneSecond = 1000000;
+
+// This is guaranteed not to use signals.
+inline bool sat_usleep(int32 microseconds) {
+  timespec req;
+  req.tv_sec = microseconds / 1000000;
+  // Convert microseconds argument to nano seconds.
+  req.tv_nsec = (microseconds % 1000000) * 1000;
+  return nanosleep(&req, NULL) == 0;
+}
+
+// This is guaranteed not to use signals.
+inline bool sat_sleep(time_t seconds) {
+  timespec req;
+  req.tv_sec = seconds;
+  req.tv_nsec = 0;
+  return nanosleep(&req, NULL) == 0;
+}
+
+// Get an error code description for use in error messages.
+//
+// Args:
+//   error_num: an errno error code
+inline string ErrorString(int error_num) {
+  char buf[256];
+  return string(strerror_r(error_num, buf, sizeof buf));
+}
+
+// Define handy constants here
+static const int kTicksPerSec = 100;
+static const int kMegabyte = (1024LL*1024LL);
+static const int kSatDiskPageMax = 32;
+static const int kSatDiskPage = 8;
+static const int kSatPageSize = (1024LL*1024LL);
+static const int kCacheLineSize = 64;
+static const uint16_t kNetworkPort = 19996;
+
+#endif  // STRESSAPPTEST_SATTYPES_H_
diff --git a/src/stressapptest_config.h.in b/src/stressapptest_config.h.in
new file mode 100644
index 0000000..6ae6e5a
--- /dev/null
+++ b/src/stressapptest_config.h.in
@@ -0,0 +1,222 @@
+/* src/stressapptest_config.h.in.  Generated from configure.ac by autoheader.  */
+
+/* Define to 1 if the `closedir' function returns void instead of `int'. */
+#undef CLOSEDIR_VOID
+
+/* Define to 1 if you have the <arpa/inet.h> header file. */
+#undef HAVE_ARPA_INET_H
+
+/* Define to 1 if you have the declaration of `strerror_r', and to 0 if you
+   don't. */
+#undef HAVE_DECL_STRERROR_R
+
+/* Define to 1 if you have the <dirent.h> header file, and it defines `DIR'.
+   */
+#undef HAVE_DIRENT_H
+
+/* Define to 1 if you don't have `vprintf' but do have `_doprnt.' */
+#undef HAVE_DOPRNT
+
+/* Define to 1 if you have the <fcntl.h> header file. */
+#undef HAVE_FCNTL_H
+
+/* Define to 1 if you have the `gettimeofday' function. */
+#undef HAVE_GETTIMEOFDAY
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#undef HAVE_INTTYPES_H
+
+/* Define to 1 if you have the <libaio.h> header file. */
+#undef HAVE_LIBAIO_H
+
+/* Define to 1 if you have the <malloc.h> header file. */
+#undef HAVE_MALLOC_H
+
+/* Define to 1 if you have the <memory.h> header file. */
+#undef HAVE_MEMORY_H
+
+/* Define to 1 if you have the `memset' function. */
+#undef HAVE_MEMSET
+
+/* Define to 1 if you have the <ndir.h> header file, and it defines `DIR'. */
+#undef HAVE_NDIR_H
+
+/* Define to 1 if you have the <netdb.h> header file. */
+#undef HAVE_NETDB_H
+
+/* Define to 1 if you have the <pthread.h> header file. */
+#undef HAVE_PTHREAD_H
+
+/* Define to 1 if you have the `select' function. */
+#undef HAVE_SELECT
+
+/* Define to 1 if you have the `socket' function. */
+#undef HAVE_SOCKET
+
+/* Define to 1 if stdbool.h conforms to C99. */
+#undef HAVE_STDBOOL_H
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#undef HAVE_STDINT_H
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#undef HAVE_STDLIB_H
+
+/* Define to 1 if you have the `strerror_r' function. */
+#undef HAVE_STRERROR_R
+
+/* Define to 1 if you have the <strings.h> header file. */
+#undef HAVE_STRINGS_H
+
+/* Define to 1 if you have the <string.h> header file. */
+#undef HAVE_STRING_H
+
+/* Define to 1 if you have the `strtol' function. */
+#undef HAVE_STRTOL
+
+/* Define to 1 if you have the `strtoull' function. */
+#undef HAVE_STRTOULL
+
+/* Define to 1 if you have the <sys/dir.h> header file, and it defines `DIR'.
+   */
+#undef HAVE_SYS_DIR_H
+
+/* Define to 1 if you have the <sys/ioctl.h> header file. */
+#undef HAVE_SYS_IOCTL_H
+
+/* Define to 1 if you have the <sys/ndir.h> header file, and it defines `DIR'.
+   */
+#undef HAVE_SYS_NDIR_H
+
+/* Define to 1 if you have the <sys/select.h> header file. */
+#undef HAVE_SYS_SELECT_H
+
+/* Define to 1 if you have the <sys/shm.h> header file. */
+#undef HAVE_SYS_SHM_H
+
+/* Define to 1 if you have the <sys/socket.h> header file. */
+#undef HAVE_SYS_SOCKET_H
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#undef HAVE_SYS_STAT_H
+
+/* Define to 1 if you have the <sys/time.h> header file. */
+#undef HAVE_SYS_TIME_H
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#undef HAVE_SYS_TYPES_H
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#undef HAVE_UNISTD_H
+
+/* Define to 1 if you have the `vprintf' function. */
+#undef HAVE_VPRINTF
+
+/* Define to 1 if the system has the type `_Bool'. */
+#undef HAVE__BOOL
+
+/* Name of package */
+#undef PACKAGE
+
+/* Define to the address where bug reports for this package should be sent. */
+#undef PACKAGE_BUGREPORT
+
+/* Define to the full name of this package. */
+#undef PACKAGE_NAME
+
+/* Define to the full name and version of this package. */
+#undef PACKAGE_STRING
+
+/* Define to the one symbol short name of this package. */
+#undef PACKAGE_TARNAME
+
+/* Define to the home page for this package. */
+#undef PACKAGE_URL
+
+/* Define to the version of this package. */
+#undef PACKAGE_VERSION
+
+/* Define as the return type of signal handlers (`int' or `void'). */
+#undef RETSIGTYPE
+
+/* Define to the type of arg 1 for `select'. */
+#undef SELECT_TYPE_ARG1
+
+/* Define to the type of args 2, 3 and 4 for `select'. */
+#undef SELECT_TYPE_ARG234
+
+/* Define to the type of arg 5 for `select'. */
+#undef SELECT_TYPE_ARG5
+
+/* Define to 1 if you have the ANSI C header files. */
+#undef STDC_HEADERS
+
+/* Define to 1 if strerror_r returns char *. */
+#undef STRERROR_R_CHAR_P
+
+/* Defined if the target CPU is armv7a */
+#undef STRESSAPPTEST_CPU_ARMV7A
+
+/* Defined if the target CPU is i686 */
+#undef STRESSAPPTEST_CPU_I686
+
+/* Defined if the target CPU is PowerPC */
+#undef STRESSAPPTEST_CPU_PPC
+
+/* Defined if the target CPU is x86_64 */
+#undef STRESSAPPTEST_CPU_X86_64
+
+/* Defined if the target OS is BSD based */
+#undef STRESSAPPTEST_OS_BSD
+
+/* Defined if the target OS is OSX */
+#undef STRESSAPPTEST_OS_DARWIN
+
+/* Defined if the target OS is Linux */
+#undef STRESSAPPTEST_OS_LINUX
+
+/* Timestamp when ./configure was executed */
+#undef STRESSAPPTEST_TIMESTAMP
+
+/* Define to 1 if you can safely include both <sys/time.h> and <time.h>. */
+#undef TIME_WITH_SYS_TIME
+
+/* Version number of package */
+#undef VERSION
+
+/* Define to empty if `const' does not conform to ANSI C. */
+#undef const
+
+/* Define to `__inline__' or `__inline' if that's what the C compiler
+   calls it, or to nothing if 'inline' is not supported under any name.  */
+#ifndef __cplusplus
+#undef inline
+#endif
+
+/* Define to `int' if <sys/types.h> does not define. */
+#undef pid_t
+
+/* Define to the equivalent of the C99 'restrict' keyword, or to
+   nothing if this is not supported.  Do not define if restrict is
+   supported directly.  */
+#undef restrict
+/* Work around a bug in Sun C++: it does not support _Restrict or
+   __restrict__, even though the corresponding Sun C compiler ends up with
+   "#define restrict _Restrict" or "#define restrict __restrict__" in the
+   previous line.  Perhaps some future version of Sun C++ will work with
+   restrict; if so, hopefully it defines __RESTRICT like Sun C does.  */
+#if defined __SUNPRO_CC && !defined __RESTRICT
+# define _Restrict
+# define __restrict__
+#endif
+
+/* Define to `int' if <sys/types.h> does not define. */
+#undef ssize_t
+
+/* Define to the type of an unsigned integer type of width exactly 16 bits if
+   such a type exists and the standard includes do not define it. */
+#undef uint16_t
+
+/* Define to empty if the keyword `volatile' does not work. Warning: valid
+   code using `volatile' can become incorrect without. Disable with care. */
+#undef volatile
diff --git a/src/worker.cc b/src/worker.cc
new file mode 100644
index 0000000..2fab28e
--- /dev/null
+++ b/src/worker.cc
@@ -0,0 +1,3344 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// worker.cc : individual tasks that can be run in combination to
+// stress the system
+
+#include <errno.h>
+#include <pthread.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <sys/select.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/times.h>
+
+// These are necessary, but on by default
+// #define __USE_GNU
+// #define __USE_LARGEFILE64
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+#include <linux/unistd.h>  // for gettid
+
+// For size of block device
+#include <sys/ioctl.h>
+#include <linux/fs.h>
+// For asynchronous I/O
+#include <libaio.h>
+
+#include <sys/syscall.h>
+
+#include <set>
+#include <string>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "error_diag.h"  // NOLINT
+#include "os.h"          // NOLINT
+#include "pattern.h"     // NOLINT
+#include "queue.h"       // NOLINT
+#include "sat.h"         // NOLINT
+#include "sattypes.h"    // NOLINT
+#include "worker.h"      // NOLINT
+
+// Syscalls
+// Why ubuntu, do you hate gettid so bad?
+#if !defined(__NR_gettid)
+  #define __NR_gettid             224
+#endif
+
+#define gettid() syscall(__NR_gettid)
+#if !defined(CPU_SETSIZE)
+_syscall3(int, sched_getaffinity, pid_t, pid,
+          unsigned int, len, cpu_set_t*, mask)
+_syscall3(int, sched_setaffinity, pid_t, pid,
+          unsigned int, len, cpu_set_t*, mask)
+#endif
+
+// Linux aio syscalls.
+#if !defined(__NR_io_setup)
+#error "No aio headers inculded, please install libaio."
+#endif
+
+namespace {
+  // Get HW core ID from cpuid instruction.
+  inline int apicid(void) {
+    int cpu;
+#if defined(STRESSAPPTEST_CPU_X86_64) || defined(STRESSAPPTEST_CPU_I686)
+    __asm __volatile("cpuid" : "=b" (cpu) : "a" (1) : "cx", "dx");
+#elif defined(STRESSAPPTEST_CPU_ARMV7A)
+  #warning "Unsupported CPU type ARMV7A: unable to determine core ID."
+    cpu = 0;
+#else
+  #warning "Unsupported CPU type: unable to determine core ID."
+    cpu = 0;
+#endif
+    return (cpu >> 24);
+  }
+
+  // Work around the sad fact that there are two (gnu, xsi) incompatible
+  // versions of strerror_r floating around google. Awesome.
+  bool sat_strerror(int err, char *buf, int len) {
+    buf[0] = 0;
+    char *errmsg = reinterpret_cast<char*>(strerror_r(err, buf, len));
+    int retval = reinterpret_cast<int64>(errmsg);
+    if (retval == 0)
+      return true;
+    if (retval == -1)
+      return false;
+    if (errmsg != buf) {
+      strncpy(buf, errmsg, len);
+      buf[len - 1] = 0;
+    }
+    return true;
+  }
+
+
+  inline uint64 addr_to_tag(void *address) {
+    return reinterpret_cast<uint64>(address);
+  }
+}
+
+#if !defined(O_DIRECT)
+// Sometimes this isn't available.
+// Disregard if it's not defined.
+  #define O_DIRECT            0
+#endif
+
+// A struct to hold captured errors, for later reporting.
+struct ErrorRecord {
+  uint64 actual;  // This is the actual value read.
+  uint64 reread;  // This is the actual value, reread.
+  uint64 expected;  // This is what it should have been.
+  uint64 *vaddr;  // This is where it was (or wasn't).
+  char *vbyteaddr;  // This is byte specific where the data was (or wasn't).
+  uint64 paddr;  // This is the bus address, if available.
+  uint64 *tagvaddr;  // This holds the tag value if this data was tagged.
+  uint64 tagpaddr;  // This holds the physical address corresponding to the tag.
+};
+
+// This is a helper function to create new threads with pthreads.
+static void *ThreadSpawnerGeneric(void *ptr) {
+  WorkerThread *worker = static_cast<WorkerThread*>(ptr);
+  worker->StartRoutine();
+  return NULL;
+}
+
+void WorkerStatus::Initialize() {
+  sat_assert(0 == pthread_mutex_init(&num_workers_mutex_, NULL));
+  sat_assert(0 == pthread_rwlock_init(&status_rwlock_, NULL));
+  sat_assert(0 == pthread_barrier_init(&pause_barrier_, NULL,
+                                       num_workers_ + 1));
+}
+
+void WorkerStatus::Destroy() {
+  sat_assert(0 == pthread_mutex_destroy(&num_workers_mutex_));
+  sat_assert(0 == pthread_rwlock_destroy(&status_rwlock_));
+  sat_assert(0 == pthread_barrier_destroy(&pause_barrier_));
+}
+
+void WorkerStatus::PauseWorkers() {
+  if (SetStatus(PAUSE) != PAUSE)
+    WaitOnPauseBarrier();
+}
+
+void WorkerStatus::ResumeWorkers() {
+  if (SetStatus(RUN) == PAUSE)
+    WaitOnPauseBarrier();
+}
+
+void WorkerStatus::StopWorkers() {
+  if (SetStatus(STOP) == PAUSE)
+    WaitOnPauseBarrier();
+}
+
+bool WorkerStatus::ContinueRunning() {
+  // This loop is an optimization.  We use it to immediately re-check the status
+  // after resuming from a pause, instead of returning and waiting for the next
+  // call to this function.
+  for (;;) {
+    switch (GetStatus()) {
+      case RUN:
+        return true;
+      case PAUSE:
+        // Wait for the other workers to call this function so that
+        // PauseWorkers() can return.
+        WaitOnPauseBarrier();
+        // Wait for ResumeWorkers() to be called.
+        WaitOnPauseBarrier();
+        break;
+      case STOP:
+        return false;
+    }
+  }
+}
+
+bool WorkerStatus::ContinueRunningNoPause() {
+  return (GetStatus() != STOP);
+}
+
+void WorkerStatus::RemoveSelf() {
+  // Acquire a read lock on status_rwlock_ while (status_ != PAUSE).
+  for (;;) {
+    AcquireStatusReadLock();
+    if (status_ != PAUSE)
+      break;
+    // We need to obey PauseWorkers() just like ContinueRunning() would, so that
+    // the other threads won't wait on pause_barrier_ forever.
+    ReleaseStatusLock();
+    // Wait for the other workers to call this function so that PauseWorkers()
+    // can return.
+    WaitOnPauseBarrier();
+    // Wait for ResumeWorkers() to be called.
+    WaitOnPauseBarrier();
+  }
+
+  // This lock would be unnecessary if we held a write lock instead of a read
+  // lock on status_rwlock_, but that would also force all threads calling
+  // ContinueRunning() to wait on this one.  Using a separate lock avoids that.
+  AcquireNumWorkersLock();
+  // Decrement num_workers_ and reinitialize pause_barrier_, which we know isn't
+  // in use because (status != PAUSE).
+  sat_assert(0 == pthread_barrier_destroy(&pause_barrier_));
+  sat_assert(0 == pthread_barrier_init(&pause_barrier_, NULL, num_workers_));
+  --num_workers_;
+  ReleaseNumWorkersLock();
+
+  // Release status_rwlock_.
+  ReleaseStatusLock();
+}
+
+
+// Parent thread class.
+WorkerThread::WorkerThread() {
+  status_ = false;
+  pages_copied_ = 0;
+  errorcount_ = 0;
+  runduration_usec_ = 1;
+  priority_ = Normal;
+  worker_status_ = NULL;
+  thread_spawner_ = &ThreadSpawnerGeneric;
+  tag_mode_ = false;
+}
+
+WorkerThread::~WorkerThread() {}
+
+// Constructors. Just init some default values.
+FillThread::FillThread() {
+  num_pages_to_fill_ = 0;
+}
+
+// Initialize file name to empty.
+FileThread::FileThread() {
+  filename_ = "";
+  devicename_ = "";
+  pass_ = 0;
+  page_io_ = true;
+  crc_page_ = -1;
+  local_page_ = NULL;
+}
+
+// If file thread used bounce buffer in memory, account for the extra
+// copy for memory bandwidth calculation.
+float FileThread::GetMemoryCopiedData() {
+  if (!os_->normal_mem())
+    return GetCopiedData();
+  else
+    return 0;
+}
+
+// Initialize target hostname to be invalid.
+NetworkThread::NetworkThread() {
+  snprintf(ipaddr_, sizeof(ipaddr_), "Unknown");
+  sock_ = 0;
+}
+
+// Initialize?
+NetworkSlaveThread::NetworkSlaveThread() {
+}
+
+// Initialize?
+NetworkListenThread::NetworkListenThread() {
+}
+
+// Init member variables.
+void WorkerThread::InitThread(int thread_num_init,
+                              class Sat *sat_init,
+                              class OsLayer *os_init,
+                              class PatternList *patternlist_init,
+                              WorkerStatus *worker_status) {
+  sat_assert(worker_status);
+  worker_status->AddWorkers(1);
+
+  thread_num_ = thread_num_init;
+  sat_ = sat_init;
+  os_ = os_init;
+  patternlist_ = patternlist_init;
+  worker_status_ = worker_status;
+
+  AvailableCpus(&cpu_mask_);
+  tag_ = 0xffffffff;
+
+  tag_mode_ = sat_->tag_mode();
+}
+
+
+// Use pthreads to prioritize a system thread.
+bool WorkerThread::InitPriority() {
+  // This doesn't affect performance that much, and may not be too safe.
+
+  bool ret = BindToCpus(&cpu_mask_);
+  if (!ret)
+    logprintf(11, "Log: Bind to %s failed.\n",
+              cpuset_format(&cpu_mask_).c_str());
+
+  logprintf(11, "Log: Thread %d running on apic ID %d mask %s (%s).\n",
+            thread_num_, apicid(),
+            CurrentCpusFormat().c_str(),
+            cpuset_format(&cpu_mask_).c_str());
+#if 0
+  if (priority_ == High) {
+    sched_param param;
+    param.sched_priority = 1;
+    // Set the priority; others are unchanged.
+    logprintf(0, "Log: Changing priority to SCHED_FIFO %d\n",
+              param.sched_priority);
+    if (sched_setscheduler(0, SCHED_FIFO, &param)) {
+      char buf[256];
+      sat_strerror(errno, buf, sizeof(buf));
+      logprintf(0, "Process Error: sched_setscheduler "
+                   "failed - error %d %s\n",
+                errno, buf);
+    }
+  }
+#endif
+  return true;
+}
+
+// Use pthreads to create a system thread.
+int WorkerThread::SpawnThread() {
+  // Create the new thread.
+  int result = pthread_create(&thread_, NULL, thread_spawner_, this);
+  if (result) {
+    char buf[256];
+    sat_strerror(result, buf, sizeof(buf));
+    logprintf(0, "Process Error: pthread_create "
+                  "failed - error %d %s\n", result,
+              buf);
+    status_ = false;
+    return false;
+  }
+
+  // 0 is pthreads success.
+  return true;
+}
+
+// Kill the worker thread with SIGINT.
+bool WorkerThread::KillThread() {
+  return (pthread_kill(thread_, SIGINT) == 0);
+}
+
+// Block until thread has exited.
+bool WorkerThread::JoinThread() {
+  int result = pthread_join(thread_, NULL);
+
+  if (result) {
+    logprintf(0, "Process Error: pthread_join failed - error %d\n", result);
+    status_ = false;
+  }
+
+  // 0 is pthreads success.
+  return (!result);
+}
+
+
+void WorkerThread::StartRoutine() {
+  InitPriority();
+  StartThreadTimer();
+  Work();
+  StopThreadTimer();
+  worker_status_->RemoveSelf();
+}
+
+
+// Thread work loop. Execute until marked finished.
+bool WorkerThread::Work() {
+  do {
+    logprintf(9, "Log: ...\n");
+    // Sleep for 1 second.
+    sat_sleep(1);
+  } while (IsReadyToRun());
+
+  return false;
+}
+
+
+// Returns CPU mask of CPUs available to this process,
+// Conceptually, each bit represents a logical CPU, ie:
+//   mask = 3  (11b):   cpu0, 1
+//   mask = 13 (1101b): cpu0, 2, 3
+bool WorkerThread::AvailableCpus(cpu_set_t *cpuset) {
+  CPU_ZERO(cpuset);
+  return sched_getaffinity(getppid(), sizeof(*cpuset), cpuset) == 0;
+}
+
+
+// Returns CPU mask of CPUs this thread is bound to,
+// Conceptually, each bit represents a logical CPU, ie:
+//   mask = 3  (11b):   cpu0, 1
+//   mask = 13 (1101b): cpu0, 2, 3
+bool WorkerThread::CurrentCpus(cpu_set_t *cpuset) {
+  CPU_ZERO(cpuset);
+  return sched_getaffinity(0, sizeof(*cpuset), cpuset) == 0;
+}
+
+
+// Bind worker thread to specified CPU(s)
+//   Args:
+//     thread_mask: cpu_set_t representing CPUs, ie
+//                  mask = 1  (01b):   cpu0
+//                  mask = 3  (11b):   cpu0, 1
+//                  mask = 13 (1101b): cpu0, 2, 3
+//
+//   Returns true on success, false otherwise.
+bool WorkerThread::BindToCpus(const cpu_set_t *thread_mask) {
+  cpu_set_t process_mask;
+  AvailableCpus(&process_mask);
+  if (cpuset_isequal(thread_mask, &process_mask))
+    return true;
+
+  logprintf(11, "Log: available CPU mask - %s\n",
+            cpuset_format(&process_mask).c_str());
+  if (!cpuset_issubset(thread_mask, &process_mask)) {
+    // Invalid cpu_mask, ie cpu not allocated to this process or doesn't exist.
+    logprintf(0, "Log: requested CPUs %s not a subset of available %s\n",
+              cpuset_format(thread_mask).c_str(),
+              cpuset_format(&process_mask).c_str());
+    return false;
+  }
+  return (sched_setaffinity(gettid(), sizeof(*thread_mask), thread_mask) == 0);
+}
+
+
+// A worker thread can yield itself to give up CPU until it's scheduled again.
+//   Returns true on success, false on error.
+bool WorkerThread::YieldSelf() {
+  return (sched_yield() == 0);
+}
+
+
+// Fill this page with its pattern.
+bool WorkerThread::FillPage(struct page_entry *pe) {
+  // Error check arguments.
+  if (pe == 0) {
+    logprintf(0, "Process Error: Fill Page entry null\n");
+    return 0;
+  }
+
+  // Mask is the bitmask of indexes used by the pattern.
+  // It is the pattern size -1. Size is always a power of 2.
+  uint64 *memwords = static_cast<uint64*>(pe->addr);
+  int length = sat_->page_length();
+
+  if (tag_mode_) {
+    // Select tag or data as appropriate.
+    for (int i = 0; i < length / wordsize_; i++) {
+      datacast_t data;
+
+      if ((i & 0x7) == 0) {
+        data.l64 = addr_to_tag(&memwords[i]);
+      } else {
+        data.l32.l = pe->pattern->pattern(i << 1);
+        data.l32.h = pe->pattern->pattern((i << 1) + 1);
+      }
+      memwords[i] = data.l64;
+    }
+  } else {
+    // Just fill in untagged data directly.
+    for (int i = 0; i < length / wordsize_; i++) {
+      datacast_t data;
+
+      data.l32.l = pe->pattern->pattern(i << 1);
+      data.l32.h = pe->pattern->pattern((i << 1) + 1);
+      memwords[i] = data.l64;
+    }
+  }
+
+  return 1;
+}
+
+
+// Tell the thread how many pages to fill.
+void FillThread::SetFillPages(int64 num_pages_to_fill_init) {
+  num_pages_to_fill_ = num_pages_to_fill_init;
+}
+
+// Fill this page with a random pattern.
+bool FillThread::FillPageRandom(struct page_entry *pe) {
+  // Error check arguments.
+  if (pe == 0) {
+    logprintf(0, "Process Error: Fill Page entry null\n");
+    return 0;
+  }
+  if ((patternlist_ == 0) || (patternlist_->Size() == 0)) {
+    logprintf(0, "Process Error: No data patterns available\n");
+    return 0;
+  }
+
+  // Choose a random pattern for this block.
+  pe->pattern = patternlist_->GetRandomPattern();
+  if (pe->pattern == 0) {
+    logprintf(0, "Process Error: Null data pattern\n");
+    return 0;
+  }
+
+  // Actually fill the page.
+  return FillPage(pe);
+}
+
+
+// Memory fill work loop. Execute until alloted pages filled.
+bool FillThread::Work() {
+  bool result = true;
+
+  logprintf(9, "Log: Starting fill thread %d\n", thread_num_);
+
+  // We want to fill num_pages_to_fill pages, and
+  // stop when we've filled that many.
+  // We also want to capture early break
+  struct page_entry pe;
+  int64 loops = 0;
+  while (IsReadyToRun() && (loops < num_pages_to_fill_)) {
+    result = result && sat_->GetEmpty(&pe);
+    if (!result) {
+      logprintf(0, "Process Error: fill_thread failed to pop pages, "
+                "bailing\n");
+      break;
+    }
+
+    // Fill the page with pattern
+    result = result && FillPageRandom(&pe);
+    if (!result) break;
+
+    // Put the page back on the queue.
+    result = result && sat_->PutValid(&pe);
+    if (!result) {
+      logprintf(0, "Process Error: fill_thread failed to push pages, "
+                "bailing\n");
+      break;
+    }
+    loops++;
+  }
+
+  // Fill in thread status.
+  pages_copied_ = loops;
+  status_ = result;
+  logprintf(9, "Log: Completed %d: Fill thread. Status %d, %d pages filled\n",
+            thread_num_, status_, pages_copied_);
+  return result;
+}
+
+
+// Print error information about a data miscompare.
+void WorkerThread::ProcessError(struct ErrorRecord *error,
+                                int priority,
+                                const char *message) {
+  char dimm_string[256] = "";
+
+  int apic_id = apicid();
+
+  // Determine if this is a write or read error.
+  os_->Flush(error->vaddr);
+  error->reread = *(error->vaddr);
+
+  char *good = reinterpret_cast<char*>(&(error->expected));
+  char *bad = reinterpret_cast<char*>(&(error->actual));
+
+  sat_assert(error->expected != error->actual);
+  unsigned int offset = 0;
+  for (offset = 0; offset < (sizeof(error->expected) - 1); offset++) {
+    if (good[offset] != bad[offset])
+      break;
+  }
+
+  error->vbyteaddr = reinterpret_cast<char*>(error->vaddr) + offset;
+
+  // Find physical address if possible.
+  error->paddr = os_->VirtualToPhysical(error->vbyteaddr);
+
+  // Pretty print DIMM mapping if available.
+  os_->FindDimm(error->paddr, dimm_string, sizeof(dimm_string));
+
+  // Report parseable error.
+  if (priority < 5) {
+    // Run miscompare error through diagnoser for logging and reporting.
+    os_->error_diagnoser_->AddMiscompareError(dimm_string,
+                                              reinterpret_cast<uint64>
+                                              (error->vaddr), 1);
+
+    logprintf(priority,
+              "%s: miscompare on CPU %d(0x%s) at %p(0x%llx:%s): "
+              "read:0x%016llx, reread:0x%016llx expected:0x%016llx\n",
+              message,
+              apic_id,
+              CurrentCpusFormat().c_str(),
+              error->vaddr,
+              error->paddr,
+              dimm_string,
+              error->actual,
+              error->reread,
+              error->expected);
+  }
+
+
+  // Overwrite incorrect data with correct data to prevent
+  // future miscompares when this data is reused.
+  *(error->vaddr) = error->expected;
+  os_->Flush(error->vaddr);
+}
+
+
+
+// Print error information about a data miscompare.
+void FileThread::ProcessError(struct ErrorRecord *error,
+                              int priority,
+                              const char *message) {
+  char dimm_string[256] = "";
+
+  // Determine if this is a write or read error.
+  os_->Flush(error->vaddr);
+  error->reread = *(error->vaddr);
+
+  char *good = reinterpret_cast<char*>(&(error->expected));
+  char *bad = reinterpret_cast<char*>(&(error->actual));
+
+  sat_assert(error->expected != error->actual);
+  unsigned int offset = 0;
+  for (offset = 0; offset < (sizeof(error->expected) - 1); offset++) {
+    if (good[offset] != bad[offset])
+      break;
+  }
+
+  error->vbyteaddr = reinterpret_cast<char*>(error->vaddr) + offset;
+
+  // Find physical address if possible.
+  error->paddr = os_->VirtualToPhysical(error->vbyteaddr);
+
+  // Pretty print DIMM mapping if available.
+  os_->FindDimm(error->paddr, dimm_string, sizeof(dimm_string));
+
+  // If crc_page_ is valid, ie checking content read back from file,
+  // track src/dst memory addresses. Otherwise catagorize as general
+  // mememory miscompare for CRC checking everywhere else.
+  if (crc_page_ != -1) {
+    int miscompare_byteoffset = static_cast<char*>(error->vbyteaddr) -
+                                static_cast<char*>(page_recs_[crc_page_].dst);
+    os_->error_diagnoser_->AddHDDMiscompareError(devicename_,
+                                                 crc_page_,
+                                                 miscompare_byteoffset,
+                                                 page_recs_[crc_page_].src,
+                                                 page_recs_[crc_page_].dst);
+  } else {
+    os_->error_diagnoser_->AddMiscompareError(dimm_string,
+                                              reinterpret_cast<uint64>
+                                              (error->vaddr), 1);
+  }
+
+  logprintf(priority,
+            "%s: miscompare on %s at %p(0x%llx:%s): read:0x%016llx, "
+            "reread:0x%016llx expected:0x%016llx\n",
+            message,
+            devicename_.c_str(),
+            error->vaddr,
+            error->paddr,
+            dimm_string,
+            error->actual,
+            error->reread,
+            error->expected);
+
+  // Overwrite incorrect data with correct data to prevent
+  // future miscompares when this data is reused.
+  *(error->vaddr) = error->expected;
+  os_->Flush(error->vaddr);
+}
+
+
+// Do a word by word result check of a region.
+// Print errors on mismatches.
+int WorkerThread::CheckRegion(void *addr,
+                              class Pattern *pattern,
+                              int64 length,
+                              int offset,
+                              int64 pattern_offset) {
+  uint64 *memblock = static_cast<uint64*>(addr);
+  const int kErrorLimit = 128;
+  int errors = 0;
+  int overflowerrors = 0;  // Count of overflowed errors.
+  bool page_error = false;
+  string errormessage("Hardware Error");
+  struct ErrorRecord
+    recorded[kErrorLimit];  // Queued errors for later printing.
+
+  // For each word in the data region.
+  for (int i = 0; i < length / wordsize_; i++) {
+    uint64 actual = memblock[i];
+    uint64 expected;
+
+    // Determine the value that should be there.
+    datacast_t data;
+    int index = 2 * i + pattern_offset;
+    data.l32.l = pattern->pattern(index);
+    data.l32.h = pattern->pattern(index + 1);
+    expected = data.l64;
+    // Check tags if necessary.
+    if (tag_mode_ && ((reinterpret_cast<uint64>(&memblock[i]) & 0x3f) == 0)) {
+      expected = addr_to_tag(&memblock[i]);
+    }
+
+
+    // If the value is incorrect, save an error record for later printing.
+    if (actual != expected) {
+      if (errors < kErrorLimit) {
+        recorded[errors].actual = actual;
+        recorded[errors].expected = expected;
+        recorded[errors].vaddr = &memblock[i];
+        errors++;
+      } else {
+        page_error = true;
+        // If we have overflowed the error queue, just print the errors now.
+        logprintf(10, "Log: Error record overflow, too many miscompares!\n");
+        errormessage = "Page Error";
+        break;
+      }
+    }
+  }
+
+  // Find if this is a whole block corruption.
+  if (page_error && !tag_mode_) {
+    int patsize = patternlist_->Size();
+    for (int pat = 0; pat < patsize; pat++) {
+      class Pattern *altpattern = patternlist_->GetPattern(pat);
+      const int kGood = 0;
+      const int kBad = 1;
+      const int kGoodAgain = 2;
+      const int kNoMatch = 3;
+      int state = kGood;
+      unsigned int badstart = 0;
+      unsigned int badend = 0;
+
+      // Don't match against ourself!
+      if (pattern == altpattern)
+        continue;
+
+      for (int i = 0; i < length / wordsize_; i++) {
+        uint64 actual = memblock[i];
+        datacast_t expected;
+        datacast_t possible;
+
+        // Determine the value that should be there.
+        int index = 2 * i + pattern_offset;
+
+        expected.l32.l = pattern->pattern(index);
+        expected.l32.h = pattern->pattern(index + 1);
+
+        possible.l32.l = pattern->pattern(index);
+        possible.l32.h = pattern->pattern(index + 1);
+
+        if (state == kGood) {
+          if (actual == expected.l64) {
+            continue;
+          } else if (actual == possible.l64) {
+            badstart = i;
+            badend = i;
+            state = kBad;
+            continue;
+          } else {
+            state = kNoMatch;
+            break;
+          }
+        } else if (state == kBad) {
+          if (actual == possible.l64) {
+            badend = i;
+            continue;
+          } else if (actual == expected.l64) {
+            state = kGoodAgain;
+            continue;
+          } else {
+            state = kNoMatch;
+            break;
+          }
+        } else if (state == kGoodAgain) {
+          if (actual == expected.l64) {
+            continue;
+          } else {
+            state = kNoMatch;
+            break;
+          }
+        }
+      }
+
+      if ((state == kGoodAgain) || (state == kBad)) {
+        unsigned int blockerrors = badend - badstart + 1;
+        errormessage = "Block Error";
+        ProcessError(&recorded[0], 0, errormessage.c_str());
+        logprintf(0, "Block Error: (%p) pattern %s instead of %s, "
+                  "%d bytes from offset 0x%x to 0x%x\n",
+                  &memblock[badstart],
+                  altpattern->name(), pattern->name(),
+                  blockerrors * wordsize_,
+                  offset + badstart * wordsize_,
+                  offset + badend * wordsize_);
+        errorcount_ += blockerrors;
+        return blockerrors;
+      }
+    }
+  }
+
+
+  // Process error queue after all errors have been recorded.
+  for (int err = 0; err < errors; err++) {
+    int priority = 5;
+    if (errorcount_ + err < 30)
+      priority = 0;  // Bump up the priority for the first few errors.
+    ProcessError(&recorded[err], priority, errormessage.c_str());
+  }
+
+  if (page_error) {
+    // For each word in the data region.
+    int error_recount = 0;
+    for (int i = 0; i < length / wordsize_; i++) {
+      uint64 actual = memblock[i];
+      uint64 expected;
+      datacast_t data;
+      // Determine the value that should be there.
+      int index = 2 * i + pattern_offset;
+
+      data.l32.l = pattern->pattern(index);
+      data.l32.h = pattern->pattern(index + 1);
+      expected = data.l64;
+
+      // Check tags if necessary.
+      if (tag_mode_ && ((reinterpret_cast<uint64>(&memblock[i]) & 0x3f) == 0)) {
+        expected = addr_to_tag(&memblock[i]);
+      }
+
+      // If the value is incorrect, save an error record for later printing.
+      if (actual != expected) {
+        if (error_recount < kErrorLimit) {
+          // We already reported these.
+          error_recount++;
+        } else {
+          // If we have overflowed the error queue, print the errors now.
+          struct ErrorRecord er;
+          er.actual = actual;
+          er.expected = expected;
+          er.vaddr = &memblock[i];
+
+          // Do the error printout. This will take a long time and
+          // likely change the machine state.
+          ProcessError(&er, 12, errormessage.c_str());
+          overflowerrors++;
+        }
+      }
+    }
+  }
+
+  // Keep track of observed errors.
+  errorcount_ += errors + overflowerrors;
+  return errors + overflowerrors;
+}
+
+float WorkerThread::GetCopiedData() {
+  return pages_copied_ * sat_->page_length() / kMegabyte;
+}
+
+// Calculate the CRC of a region.
+// Result check if the CRC mismatches.
+int WorkerThread::CrcCheckPage(struct page_entry *srcpe) {
+  const int blocksize = 4096;
+  const int blockwords = blocksize / wordsize_;
+  int errors = 0;
+
+  const AdlerChecksum *expectedcrc = srcpe->pattern->crc();
+  uint64 *memblock = static_cast<uint64*>(srcpe->addr);
+  int blocks = sat_->page_length() / blocksize;
+  for (int currentblock = 0; currentblock < blocks; currentblock++) {
+    uint64 *memslice = memblock + currentblock * blockwords;
+
+    AdlerChecksum crc;
+    if (tag_mode_) {
+      AdlerAddrCrcC(memslice, blocksize, &crc, srcpe);
+    } else {
+      CalculateAdlerChecksum(memslice, blocksize, &crc);
+    }
+
+    // If the CRC does not match, we'd better look closer.
+    if (!crc.Equals(*expectedcrc)) {
+      logprintf(11, "Log: CrcCheckPage Falling through to slow compare, "
+                "CRC mismatch %s != %s\n",
+                crc.ToHexString().c_str(),
+                expectedcrc->ToHexString().c_str());
+      int errorcount = CheckRegion(memslice,
+                                   srcpe->pattern,
+                                   blocksize,
+                                   currentblock * blocksize, 0);
+      if (errorcount == 0) {
+        logprintf(0, "Log: CrcCheckPage CRC mismatch %s != %s, "
+                     "but no miscompares found.\n",
+                  crc.ToHexString().c_str(),
+                  expectedcrc->ToHexString().c_str());
+      }
+      errors += errorcount;
+    }
+  }
+
+  // For odd length transfers, we should never hit this.
+  int leftovers = sat_->page_length() % blocksize;
+  if (leftovers) {
+    uint64 *memslice = memblock + blocks * blockwords;
+    errors += CheckRegion(memslice,
+                          srcpe->pattern,
+                          leftovers,
+                          blocks * blocksize, 0);
+  }
+  return errors;
+}
+
+
+// Print error information about a data miscompare.
+void WorkerThread::ProcessTagError(struct ErrorRecord *error,
+                                   int priority,
+                                   const char *message) {
+  char dimm_string[256] = "";
+  char tag_dimm_string[256] = "";
+  bool read_error = false;
+
+  int apic_id = apicid();
+
+  // Determine if this is a write or read error.
+  os_->Flush(error->vaddr);
+  error->reread = *(error->vaddr);
+
+  // Distinguish read and write errors.
+  if (error->actual != error->reread) {
+    read_error = true;
+  }
+
+  sat_assert(error->expected != error->actual);
+
+  error->vbyteaddr = reinterpret_cast<char*>(error->vaddr);
+
+  // Find physical address if possible.
+  error->paddr = os_->VirtualToPhysical(error->vbyteaddr);
+  error->tagpaddr = os_->VirtualToPhysical(error->tagvaddr);
+
+  // Pretty print DIMM mapping if available.
+  os_->FindDimm(error->paddr, dimm_string, sizeof(dimm_string));
+  // Pretty print DIMM mapping if available.
+  os_->FindDimm(error->tagpaddr, tag_dimm_string, sizeof(tag_dimm_string));
+
+  // Report parseable error.
+  if (priority < 5) {
+    logprintf(priority,
+              "%s: Tag from %p(0x%llx:%s) (%s) "
+              "miscompare on CPU %d(0x%s) at %p(0x%llx:%s): "
+              "read:0x%016llx, reread:0x%016llx expected:0x%016llx\n",
+              message,
+              error->tagvaddr, error->tagpaddr,
+              tag_dimm_string,
+              read_error ? "read error" : "write error",
+              apic_id,
+              CurrentCpusFormat().c_str(),
+              error->vaddr,
+              error->paddr,
+              dimm_string,
+              error->actual,
+              error->reread,
+              error->expected);
+  }
+
+  errorcount_ += 1;
+
+  // Overwrite incorrect data with correct data to prevent
+  // future miscompares when this data is reused.
+  *(error->vaddr) = error->expected;
+  os_->Flush(error->vaddr);
+}
+
+
+// Print out and log a tag error.
+bool WorkerThread::ReportTagError(
+    uint64 *mem64,
+    uint64 actual,
+    uint64 tag) {
+  struct ErrorRecord er;
+  er.actual = actual;
+
+  er.expected = tag;
+  er.vaddr = mem64;
+
+  // Generate vaddr from tag.
+  er.tagvaddr = reinterpret_cast<uint64*>(actual);
+
+  ProcessTagError(&er, 0, "Hardware Error");
+  return true;
+}
+
+// C implementation of Adler memory copy, with memory tagging.
+bool WorkerThread::AdlerAddrMemcpyC(uint64 *dstmem64,
+                                    uint64 *srcmem64,
+                                    unsigned int size_in_bytes,
+                                    AdlerChecksum *checksum,
+                                    struct page_entry *pe) {
+  // Use this data wrapper to access memory with 64bit read/write.
+  datacast_t data;
+  datacast_t dstdata;
+  unsigned int count = size_in_bytes / sizeof(data);
+
+  if (count > ((1U) << 19)) {
+    // Size is too large, must be strictly less than 512 KB.
+    return false;
+  }
+
+  uint64 a1 = 1;
+  uint64 a2 = 1;
+  uint64 b1 = 0;
+  uint64 b2 = 0;
+
+  class Pattern *pattern = pe->pattern;
+
+  unsigned int i = 0;
+  while (i < count) {
+    // Process 64 bits at a time.
+    if ((i & 0x7) == 0) {
+      data.l64 = srcmem64[i];
+      dstdata.l64 = dstmem64[i];
+      uint64 src_tag = addr_to_tag(&srcmem64[i]);
+      uint64 dst_tag = addr_to_tag(&dstmem64[i]);
+      // Detect if tags have been corrupted.
+      if (data.l64 != src_tag)
+        ReportTagError(&srcmem64[i], data.l64, src_tag);
+      if (dstdata.l64 != dst_tag)
+        ReportTagError(&dstmem64[i], dstdata.l64, dst_tag);
+
+      data.l32.l = pattern->pattern(i << 1);
+      data.l32.h = pattern->pattern((i << 1) + 1);
+      a1 = a1 + data.l32.l;
+      b1 = b1 + a1;
+      a1 = a1 + data.l32.h;
+      b1 = b1 + a1;
+
+      data.l64  = dst_tag;
+      dstmem64[i] = data.l64;
+
+    } else {
+      data.l64 = srcmem64[i];
+      a1 = a1 + data.l32.l;
+      b1 = b1 + a1;
+      a1 = a1 + data.l32.h;
+      b1 = b1 + a1;
+      dstmem64[i] = data.l64;
+    }
+    i++;
+
+    data.l64 = srcmem64[i];
+    a2 = a2 + data.l32.l;
+    b2 = b2 + a2;
+    a2 = a2 + data.l32.h;
+    b2 = b2 + a2;
+    dstmem64[i] = data.l64;
+    i++;
+  }
+  checksum->Set(a1, a2, b1, b2);
+  return true;
+}
+
+// x86_64 SSE2 assembly implementation of Adler memory copy, with address
+// tagging added as a second step. This is useful for debugging failures
+// that only occur when SSE / nontemporal writes are used.
+bool WorkerThread::AdlerAddrMemcpyWarm(uint64 *dstmem64,
+                                       uint64 *srcmem64,
+                                       unsigned int size_in_bytes,
+                                       AdlerChecksum *checksum,
+                                       struct page_entry *pe) {
+  // Do ASM copy, ignore checksum.
+  AdlerChecksum ignored_checksum;
+  os_->AdlerMemcpyWarm(dstmem64, srcmem64, size_in_bytes, &ignored_checksum);
+
+  // Force cache flush.
+  int length = size_in_bytes / sizeof(*dstmem64);
+  for (int i = 0; i < length; i += sizeof(*dstmem64)) {
+    os_->FastFlush(dstmem64 + i);
+    os_->FastFlush(srcmem64 + i);
+  }
+  // Check results.
+  AdlerAddrCrcC(srcmem64, size_in_bytes, checksum, pe);
+  // Patch up address tags.
+  TagAddrC(dstmem64, size_in_bytes);
+  return true;
+}
+
+// Retag pages..
+bool WorkerThread::TagAddrC(uint64 *memwords,
+                            unsigned int size_in_bytes) {
+  // Mask is the bitmask of indexes used by the pattern.
+  // It is the pattern size -1. Size is always a power of 2.
+
+  // Select tag or data as appropriate.
+  int length = size_in_bytes / wordsize_;
+  for (int i = 0; i < length; i += 8) {
+    datacast_t data;
+    data.l64 = addr_to_tag(&memwords[i]);
+    memwords[i] = data.l64;
+  }
+  return true;
+}
+
+// C implementation of Adler memory crc.
+bool WorkerThread::AdlerAddrCrcC(uint64 *srcmem64,
+                                 unsigned int size_in_bytes,
+                                 AdlerChecksum *checksum,
+                                 struct page_entry *pe) {
+  // Use this data wrapper to access memory with 64bit read/write.
+  datacast_t data;
+  unsigned int count = size_in_bytes / sizeof(data);
+
+  if (count > ((1U) << 19)) {
+    // Size is too large, must be strictly less than 512 KB.
+    return false;
+  }
+
+  uint64 a1 = 1;
+  uint64 a2 = 1;
+  uint64 b1 = 0;
+  uint64 b2 = 0;
+
+  class Pattern *pattern = pe->pattern;
+
+  unsigned int i = 0;
+  while (i < count) {
+    // Process 64 bits at a time.
+    if ((i & 0x7) == 0) {
+      data.l64 = srcmem64[i];
+      uint64 src_tag = addr_to_tag(&srcmem64[i]);
+      // Check that tags match expected.
+      if (data.l64 != src_tag)
+        ReportTagError(&srcmem64[i], data.l64, src_tag);
+
+      data.l32.l = pattern->pattern(i << 1);
+      data.l32.h = pattern->pattern((i << 1) + 1);
+      a1 = a1 + data.l32.l;
+      b1 = b1 + a1;
+      a1 = a1 + data.l32.h;
+      b1 = b1 + a1;
+    } else {
+      data.l64 = srcmem64[i];
+      a1 = a1 + data.l32.l;
+      b1 = b1 + a1;
+      a1 = a1 + data.l32.h;
+      b1 = b1 + a1;
+    }
+    i++;
+
+    data.l64 = srcmem64[i];
+    a2 = a2 + data.l32.l;
+    b2 = b2 + a2;
+    a2 = a2 + data.l32.h;
+    b2 = b2 + a2;
+    i++;
+  }
+  checksum->Set(a1, a2, b1, b2);
+  return true;
+}
+
+// Copy a block of memory quickly, while keeping a CRC of the data.
+// Result check if the CRC mismatches.
+int WorkerThread::CrcCopyPage(struct page_entry *dstpe,
+                              struct page_entry *srcpe) {
+  int errors = 0;
+  const int blocksize = 4096;
+  const int blockwords = blocksize / wordsize_;
+  int blocks = sat_->page_length() / blocksize;
+
+  // Base addresses for memory copy
+  uint64 *targetmembase = static_cast<uint64*>(dstpe->addr);
+  uint64 *sourcemembase = static_cast<uint64*>(srcpe->addr);
+  // Remember the expected CRC
+  const AdlerChecksum *expectedcrc = srcpe->pattern->crc();
+
+  for (int currentblock = 0; currentblock < blocks; currentblock++) {
+    uint64 *targetmem = targetmembase + currentblock * blockwords;
+    uint64 *sourcemem = sourcemembase + currentblock * blockwords;
+
+    AdlerChecksum crc;
+    if (tag_mode_) {
+      AdlerAddrMemcpyC(targetmem, sourcemem, blocksize, &crc, srcpe);
+    } else {
+      AdlerMemcpyC(targetmem, sourcemem, blocksize, &crc);
+    }
+
+    // Investigate miscompares.
+    if (!crc.Equals(*expectedcrc)) {
+      logprintf(11, "Log: CrcCopyPage Falling through to slow compare, "
+                "CRC mismatch %s != %s\n", crc.ToHexString().c_str(),
+                expectedcrc->ToHexString().c_str());
+      int errorcount = CheckRegion(sourcemem,
+                                   srcpe->pattern,
+                                   blocksize,
+                                   currentblock * blocksize, 0);
+      if (errorcount == 0) {
+        logprintf(0, "Log: CrcCopyPage CRC mismatch %s != %s, "
+                     "but no miscompares found. Retrying with fresh data.\n",
+                  crc.ToHexString().c_str(),
+                  expectedcrc->ToHexString().c_str());
+        if (!tag_mode_) {
+          // Copy the data originally read from this region back again.
+          // This data should have any corruption read originally while
+          // calculating the CRC.
+          memcpy(sourcemem, targetmem, blocksize);
+          errorcount = CheckRegion(sourcemem,
+                                   srcpe->pattern,
+                                   blocksize,
+                                   currentblock * blocksize, 0);
+          if (errorcount == 0) {
+            int apic_id = apicid();
+            logprintf(0, "Process Error: CPU %d(0x%s) CrcCopyPage "
+                         "CRC mismatch %s != %s, "
+                         "but no miscompares found on second pass.\n",
+                      apic_id, CurrentCpusFormat().c_str(),
+                      crc.ToHexString().c_str(),
+                      expectedcrc->ToHexString().c_str());
+            struct ErrorRecord er;
+            er.actual = sourcemem[0];
+            er.expected = 0x0;
+            er.vaddr = sourcemem;
+            ProcessError(&er, 0, "Hardware Error");
+          }
+        }
+      }
+      errors += errorcount;
+    }
+  }
+
+  // For odd length transfers, we should never hit this.
+  int leftovers = sat_->page_length() % blocksize;
+  if (leftovers) {
+    uint64 *targetmem = targetmembase + blocks * blockwords;
+    uint64 *sourcemem = sourcemembase + blocks * blockwords;
+
+    errors += CheckRegion(sourcemem,
+                          srcpe->pattern,
+                          leftovers,
+                          blocks * blocksize, 0);
+    int leftoverwords = leftovers / wordsize_;
+    for (int i = 0; i < leftoverwords; i++) {
+      targetmem[i] = sourcemem[i];
+    }
+  }
+
+  // Update pattern reference to reflect new contents.
+  dstpe->pattern = srcpe->pattern;
+
+  // Clean clean clean the errors away.
+  if (errors) {
+    // TODO(nsanders): Maybe we should patch rather than fill? Filling may
+    // cause bad data to be propogated across the page.
+    FillPage(dstpe);
+  }
+  return errors;
+}
+
+
+
+// Invert a block of memory quickly, traversing downwards.
+int InvertThread::InvertPageDown(struct page_entry *srcpe) {
+  const int blocksize = 4096;
+  const int blockwords = blocksize / wordsize_;
+  int blocks = sat_->page_length() / blocksize;
+
+  // Base addresses for memory copy
+  unsigned int *sourcemembase = static_cast<unsigned int *>(srcpe->addr);
+
+  for (int currentblock = blocks-1; currentblock >= 0; currentblock--) {
+    unsigned int *sourcemem = sourcemembase + currentblock * blockwords;
+    for (int i = blockwords - 32; i >= 0; i -= 32) {
+      for (int index = i + 31; index >= i; --index) {
+        unsigned int actual = sourcemem[index];
+        sourcemem[index] = ~actual;
+      }
+      OsLayer::FastFlush(&sourcemem[i]);
+    }
+  }
+
+  return 0;
+}
+
+// Invert a block of memory, traversing upwards.
+int InvertThread::InvertPageUp(struct page_entry *srcpe) {
+  const int blocksize = 4096;
+  const int blockwords = blocksize / wordsize_;
+  int blocks = sat_->page_length() / blocksize;
+
+  // Base addresses for memory copy
+  unsigned int *sourcemembase = static_cast<unsigned int *>(srcpe->addr);
+
+  for (int currentblock = 0; currentblock < blocks; currentblock++) {
+    unsigned int *sourcemem = sourcemembase + currentblock * blockwords;
+    for (int i = 0; i < blockwords; i += 32) {
+      for (int index = i; index <= i + 31; ++index) {
+        unsigned int actual = sourcemem[index];
+        sourcemem[index] = ~actual;
+      }
+      OsLayer::FastFlush(&sourcemem[i]);
+    }
+  }
+  return 0;
+}
+
+// Copy a block of memory quickly, while keeping a CRC of the data.
+// Result check if the CRC mismatches. Warm the CPU while running
+int WorkerThread::CrcWarmCopyPage(struct page_entry *dstpe,
+                                  struct page_entry *srcpe) {
+  int errors = 0;
+  const int blocksize = 4096;
+  const int blockwords = blocksize / wordsize_;
+  int blocks = sat_->page_length() / blocksize;
+
+  // Base addresses for memory copy
+  uint64 *targetmembase = static_cast<uint64*>(dstpe->addr);
+  uint64 *sourcemembase = static_cast<uint64*>(srcpe->addr);
+  // Remember the expected CRC
+  const AdlerChecksum *expectedcrc = srcpe->pattern->crc();
+
+  for (int currentblock = 0; currentblock < blocks; currentblock++) {
+    uint64 *targetmem = targetmembase + currentblock * blockwords;
+    uint64 *sourcemem = sourcemembase + currentblock * blockwords;
+
+    AdlerChecksum crc;
+    if (tag_mode_) {
+      AdlerAddrMemcpyWarm(targetmem, sourcemem, blocksize, &crc, srcpe);
+    } else {
+      os_->AdlerMemcpyWarm(targetmem, sourcemem, blocksize, &crc);
+    }
+
+    // Investigate miscompares.
+    if (!crc.Equals(*expectedcrc)) {
+      logprintf(11, "Log: CrcWarmCopyPage Falling through to slow compare, "
+                "CRC mismatch %s != %s\n", crc.ToHexString().c_str(),
+                expectedcrc->ToHexString().c_str());
+      int errorcount = CheckRegion(sourcemem,
+                                   srcpe->pattern,
+                                   blocksize,
+                                   currentblock * blocksize, 0);
+      if (errorcount == 0) {
+        logprintf(0, "Log: CrcWarmCopyPage CRC mismatch %s != %s, "
+                     "but no miscompares found. Retrying with fresh data.\n",
+                  crc.ToHexString().c_str(),
+                  expectedcrc->ToHexString().c_str());
+        if (!tag_mode_) {
+          // Copy the data originally read from this region back again.
+          // This data should have any corruption read originally while
+          // calculating the CRC.
+          memcpy(sourcemem, targetmem, blocksize);
+          errorcount = CheckRegion(sourcemem,
+                                   srcpe->pattern,
+                                   blocksize,
+                                   currentblock * blocksize, 0);
+          if (errorcount == 0) {
+            int apic_id = apicid();
+            logprintf(0, "Process Error: CPU %d(0x%s) CrciWarmCopyPage "
+                         "CRC mismatch %s != %s, "
+                         "but no miscompares found on second pass.\n",
+                      apic_id, CurrentCpusFormat().c_str(),
+                      crc.ToHexString().c_str(),
+                      expectedcrc->ToHexString().c_str());
+            struct ErrorRecord er;
+            er.actual = sourcemem[0];
+            er.expected = 0x0;
+            er.vaddr = sourcemem;
+            ProcessError(&er, 0, "Hardware Error");
+          }
+        }
+      }
+      errors += errorcount;
+    }
+  }
+
+  // For odd length transfers, we should never hit this.
+  int leftovers = sat_->page_length() % blocksize;
+  if (leftovers) {
+    uint64 *targetmem = targetmembase + blocks * blockwords;
+    uint64 *sourcemem = sourcemembase + blocks * blockwords;
+
+    errors += CheckRegion(sourcemem,
+                          srcpe->pattern,
+                          leftovers,
+                          blocks * blocksize, 0);
+    int leftoverwords = leftovers / wordsize_;
+    for (int i = 0; i < leftoverwords; i++) {
+      targetmem[i] = sourcemem[i];
+    }
+  }
+
+  // Update pattern reference to reflect new contents.
+  dstpe->pattern = srcpe->pattern;
+
+  // Clean clean clean the errors away.
+  if (errors) {
+    // TODO(nsanders): Maybe we should patch rather than fill? Filling may
+    // cause bad data to be propogated across the page.
+    FillPage(dstpe);
+  }
+  return errors;
+}
+
+
+
+// Memory check work loop. Execute until done, then exhaust pages.
+bool CheckThread::Work() {
+  struct page_entry pe;
+  bool result = true;
+  int64 loops = 0;
+
+  logprintf(9, "Log: Starting Check thread %d\n", thread_num_);
+
+  // We want to check all the pages, and
+  // stop when there aren't any left.
+  while (true) {
+    result = result && sat_->GetValid(&pe);
+    if (!result) {
+      if (IsReadyToRunNoPause())
+        logprintf(0, "Process Error: check_thread failed to pop pages, "
+                  "bailing\n");
+      else
+        result = true;
+      break;
+    }
+
+    // Do the result check.
+    CrcCheckPage(&pe);
+
+    // Push pages back on the valid queue if we are still going,
+    // throw them out otherwise.
+    if (IsReadyToRunNoPause())
+      result = result && sat_->PutValid(&pe);
+    else
+      result = result && sat_->PutEmpty(&pe);
+    if (!result) {
+      logprintf(0, "Process Error: check_thread failed to push pages, "
+                "bailing\n");
+      break;
+    }
+    loops++;
+  }
+
+  pages_copied_ = loops;
+  status_ = result;
+  logprintf(9, "Log: Completed %d: Check thread. Status %d, %d pages checked\n",
+            thread_num_, status_, pages_copied_);
+  return result;
+}
+
+
+// Memory copy work loop. Execute until marked done.
+bool CopyThread::Work() {
+  struct page_entry src;
+  struct page_entry dst;
+  bool result = true;
+  int64 loops = 0;
+
+  logprintf(9, "Log: Starting copy thread %d: cpu %s, mem %x\n",
+            thread_num_, cpuset_format(&cpu_mask_).c_str(), tag_);
+
+  while (IsReadyToRun()) {
+    // Pop the needed pages.
+    result = result && sat_->GetValid(&src, tag_);
+    result = result && sat_->GetEmpty(&dst, tag_);
+    if (!result) {
+      logprintf(0, "Process Error: copy_thread failed to pop pages, "
+                "bailing\n");
+      break;
+    }
+
+    // Force errors for unittests.
+    if (sat_->error_injection()) {
+      if (loops == 8) {
+        char *addr = reinterpret_cast<char*>(src.addr);
+        int offset = random() % sat_->page_length();
+        addr[offset] = 0xba;
+      }
+    }
+
+    // We can use memcpy, or CRC check while we copy.
+    if (sat_->warm()) {
+      CrcWarmCopyPage(&dst, &src);
+    } else if (sat_->strict()) {
+      CrcCopyPage(&dst, &src);
+    } else {
+      memcpy(dst.addr, src.addr, sat_->page_length());
+      dst.pattern = src.pattern;
+    }
+
+    result = result && sat_->PutValid(&dst);
+    result = result && sat_->PutEmpty(&src);
+
+    // Copy worker-threads yield themselves at the end of each copy loop,
+    // to avoid threads from preempting each other in the middle of the inner
+    // copy-loop. Cooperations between Copy worker-threads results in less
+    // unnecessary cache thrashing (which happens when context-switching in the
+    // middle of the inner copy-loop).
+    YieldSelf();
+
+    if (!result) {
+      logprintf(0, "Process Error: copy_thread failed to push pages, "
+                "bailing\n");
+      break;
+    }
+    loops++;
+  }
+
+  pages_copied_ = loops;
+  status_ = result;
+  logprintf(9, "Log: Completed %d: Copy thread. Status %d, %d pages copied\n",
+            thread_num_, status_, pages_copied_);
+  return result;
+}
+
+// Memory invert work loop. Execute until marked done.
+bool InvertThread::Work() {
+  struct page_entry src;
+  bool result = true;
+  int64 loops = 0;
+
+  logprintf(9, "Log: Starting invert thread %d\n", thread_num_);
+
+  while (IsReadyToRun()) {
+    // Pop the needed pages.
+    result = result && sat_->GetValid(&src);
+    if (!result) {
+      logprintf(0, "Process Error: invert_thread failed to pop pages, "
+                "bailing\n");
+      break;
+    }
+
+    if (sat_->strict())
+      CrcCheckPage(&src);
+
+    // For the same reason CopyThread yields itself (see YieldSelf comment
+    // in CopyThread::Work(), InvertThread yields itself after each invert
+    // operation to improve cooperation between different worker threads
+    // stressing the memory/cache.
+    InvertPageUp(&src);
+    YieldSelf();
+    InvertPageDown(&src);
+    YieldSelf();
+    InvertPageDown(&src);
+    YieldSelf();
+    InvertPageUp(&src);
+    YieldSelf();
+
+    if (sat_->strict())
+      CrcCheckPage(&src);
+
+    result = result && sat_->PutValid(&src);
+    if (!result) {
+      logprintf(0, "Process Error: invert_thread failed to push pages, "
+                "bailing\n");
+      break;
+    }
+    loops++;
+  }
+
+  pages_copied_ = loops * 2;
+  status_ = result;
+  logprintf(9, "Log: Completed %d: Copy thread. Status %d, %d pages copied\n",
+            thread_num_, status_, pages_copied_);
+  return result;
+}
+
+
+// Set file name to use for File IO.
+void FileThread::SetFile(const char *filename_init) {
+  filename_ = filename_init;
+  devicename_ = os_->FindFileDevice(filename_);
+}
+
+// Open the file for access.
+bool FileThread::OpenFile(int *pfile) {
+  int fd = open(filename_.c_str(),
+                O_RDWR | O_CREAT | O_SYNC | O_DIRECT,
+                0644);
+  if (fd < 0) {
+    logprintf(0, "Process Error: Failed to create file %s!!\n",
+              filename_.c_str());
+    pages_copied_ = 0;
+    return false;
+  }
+  *pfile = fd;
+  return true;
+}
+
+// Close the file.
+bool FileThread::CloseFile(int fd) {
+  close(fd);
+  return true;
+}
+
+// Check sector tagging.
+bool FileThread::SectorTagPage(struct page_entry *src, int block) {
+  int page_length = sat_->page_length();
+  struct FileThread::SectorTag *tag =
+    (struct FileThread::SectorTag *)(src->addr);
+
+  // Tag each sector.
+  unsigned char magic = ((0xba + thread_num_) & 0xff);
+  for (int sec = 0; sec < page_length / 512; sec++) {
+    tag[sec].magic = magic;
+    tag[sec].block = block & 0xff;
+    tag[sec].sector = sec & 0xff;
+    tag[sec].pass = pass_ & 0xff;
+  }
+  return true;
+}
+
+bool FileThread::WritePageToFile(int fd, struct page_entry *src) {
+  int page_length = sat_->page_length();
+  // Fill the file with our data.
+  int64 size = write(fd, src->addr, page_length);
+
+  if (size != page_length) {
+    os_->ErrorReport(devicename_.c_str(), "write-error", 1);
+    errorcount_++;
+    logprintf(0, "Block Error: file_thread failed to write, "
+              "bailing\n");
+    return false;
+  }
+  return true;
+}
+
+// Write the data to the file.
+bool FileThread::WritePages(int fd) {
+  int strict = sat_->strict();
+
+  // Start fresh at beginning of file for each batch of pages.
+  lseek64(fd, 0, SEEK_SET);
+  for (int i = 0; i < sat_->disk_pages(); i++) {
+    struct page_entry src;
+    if (!GetValidPage(&src))
+      return false;
+    // Save expected pattern.
+    page_recs_[i].pattern = src.pattern;
+    page_recs_[i].src = src.addr;
+
+    // Check data correctness.
+    if (strict)
+      CrcCheckPage(&src);
+
+    SectorTagPage(&src, i);
+
+    bool result = WritePageToFile(fd, &src);
+
+    if (!PutEmptyPage(&src))
+      return false;
+
+    if (!result)
+      return false;
+  }
+  return true;
+}
+
+// Copy data from file into memory block.
+bool FileThread::ReadPageFromFile(int fd, struct page_entry *dst) {
+  int page_length = sat_->page_length();
+
+  // Do the actual read.
+  int64 size = read(fd, dst->addr, page_length);
+  if (size != page_length) {
+    os_->ErrorReport(devicename_.c_str(), "read-error", 1);
+    logprintf(0, "Block Error: file_thread failed to read, "
+              "bailing\n");
+    errorcount_++;
+    return false;
+  }
+  return true;
+}
+
+// Check sector tagging.
+bool FileThread::SectorValidatePage(const struct PageRec &page,
+                                    struct page_entry *dst, int block) {
+  // Error injection.
+  static int calls = 0;
+  calls++;
+
+  // Do sector tag compare.
+  int firstsector = -1;
+  int lastsector = -1;
+  bool badsector = false;
+  int page_length = sat_->page_length();
+
+  // Cast data block into an array of tagged sectors.
+  struct FileThread::SectorTag *tag =
+  (struct FileThread::SectorTag *)(dst->addr);
+
+  sat_assert(sizeof(*tag) == 512);
+
+  // Error injection.
+  if (sat_->error_injection()) {
+    if (calls == 2) {
+      for (int badsec = 8; badsec < 17; badsec++)
+        tag[badsec].pass = 27;
+    }
+    if (calls == 18) {
+      (static_cast<int32*>(dst->addr))[27] = 0xbadda7a;
+    }
+  }
+
+  // Check each sector for the correct tag we added earlier,
+  // then revert the tag to the to normal data pattern.
+  unsigned char magic = ((0xba + thread_num_) & 0xff);
+  for (int sec = 0; sec < page_length / 512; sec++) {
+    // Check magic tag.
+    if ((tag[sec].magic != magic) ||
+        (tag[sec].block != (block & 0xff)) ||
+        (tag[sec].sector != (sec & 0xff)) ||
+        (tag[sec].pass != (pass_ & 0xff))) {
+      // Offset calculation for tag location.
+      int offset = sec * sizeof(SectorTag);
+      if (tag[sec].block != (block & 0xff))
+        offset += 1 * sizeof(uint8);
+      else if (tag[sec].sector != (sec & 0xff))
+        offset += 2 * sizeof(uint8);
+      else if (tag[sec].pass != (pass_ & 0xff))
+        offset += 3 * sizeof(uint8);
+
+      // Run sector tag error through diagnoser for logging and reporting.
+      errorcount_ += 1;
+      os_->error_diagnoser_->AddHDDSectorTagError(devicename_, tag[sec].block,
+                                                  offset,
+                                                  tag[sec].sector,
+                                                  page.src, page.dst);
+
+      logprintf(5, "Sector Error: Sector tag @ 0x%x, pass %d/%d. "
+                "sec %x/%x, block %d/%d, magic %x/%x, File: %s \n",
+                block * page_length + 512 * sec,
+                (pass_ & 0xff), (unsigned int)tag[sec].pass,
+                sec, (unsigned int)tag[sec].sector,
+                block, (unsigned int)tag[sec].block,
+                magic, (unsigned int)tag[sec].magic,
+                filename_.c_str());
+
+      // Keep track of first and last bad sector.
+      if (firstsector == -1)
+        firstsector = (block * page_length / 512) + sec;
+      lastsector = (block * page_length / 512) + sec;
+      badsector = true;
+    }
+    // Patch tag back to proper pattern.
+    unsigned int *addr = (unsigned int *)(&tag[sec]);
+    *addr = dst->pattern->pattern(512 * sec / sizeof(*addr));
+  }
+
+  // If we found sector errors:
+  if (badsector == true) {
+    logprintf(5, "Log: file sector miscompare at offset %x-%x. File: %s\n",
+              firstsector * 512,
+              ((lastsector + 1) * 512) - 1,
+              filename_.c_str());
+
+    // Either exit immediately, or patch the data up and continue.
+    if (sat_->stop_on_error()) {
+      exit(1);
+    } else {
+      // Patch up bad pages.
+      for (int block = (firstsector * 512) / page_length;
+          block <= (lastsector * 512) / page_length;
+          block++) {
+        unsigned int *memblock = static_cast<unsigned int *>(dst->addr);
+        int length = page_length / wordsize_;
+        for (int i = 0; i < length; i++) {
+          memblock[i] = dst->pattern->pattern(i);
+        }
+      }
+    }
+  }
+  return true;
+}
+
+// Get memory for an incoming data transfer..
+bool FileThread::PagePrepare() {
+  // We can only do direct IO to SAT pages if it is normal mem.
+  page_io_ = os_->normal_mem();
+
+  // Init a local buffer if we need it.
+  if (!page_io_) {
+    int result = posix_memalign(&local_page_, 512, sat_->page_length());
+    if (result) {
+      logprintf(0, "Process Error: disk thread posix_memalign "
+                   "returned %d (fail)\n",
+                result);
+      status_ = false;
+      return false;
+    }
+  }
+  return true;
+}
+
+
+// Remove memory allocated for data transfer.
+bool FileThread::PageTeardown() {
+  // Free a local buffer if we need to.
+  if (!page_io_) {
+    free(local_page_);
+  }
+  return true;
+}
+
+
+
+// Get memory for an incoming data transfer..
+bool FileThread::GetEmptyPage(struct page_entry *dst) {
+  if (page_io_) {
+    if (!sat_->GetEmpty(dst))
+      return false;
+  } else {
+    dst->addr = local_page_;
+    dst->offset = 0;
+    dst->pattern = 0;
+  }
+  return true;
+}
+
+// Get memory for an outgoing data transfer..
+bool FileThread::GetValidPage(struct page_entry *src) {
+  struct page_entry tmp;
+  if (!sat_->GetValid(&tmp))
+    return false;
+  if (page_io_) {
+    *src = tmp;
+    return true;
+  } else {
+    src->addr = local_page_;
+    src->offset = 0;
+    CrcCopyPage(src, &tmp);
+    if (!sat_->PutValid(&tmp))
+      return false;
+  }
+  return true;
+}
+
+
+// Throw out a used empty page.
+bool FileThread::PutEmptyPage(struct page_entry *src) {
+  if (page_io_) {
+    if (!sat_->PutEmpty(src))
+      return false;
+  }
+  return true;
+}
+
+// Throw out a used, filled page.
+bool FileThread::PutValidPage(struct page_entry *src) {
+  if (page_io_) {
+    if (!sat_->PutValid(src))
+      return false;
+  }
+  return true;
+}
+
+// Copy data from file into memory blocks.
+bool FileThread::ReadPages(int fd) {
+  int page_length = sat_->page_length();
+  int strict = sat_->strict();
+  bool result = true;
+
+  // Read our data back out of the file, into it's new location.
+  lseek64(fd, 0, SEEK_SET);
+  for (int i = 0; i < sat_->disk_pages(); i++) {
+    struct page_entry dst;
+    if (!GetEmptyPage(&dst))
+      return false;
+    // Retrieve expected pattern.
+    dst.pattern = page_recs_[i].pattern;
+    // Update page recordpage record.
+    page_recs_[i].dst = dst.addr;
+
+    // Read from the file into destination page.
+    if (!ReadPageFromFile(fd, &dst)) {
+        PutEmptyPage(&dst);
+        return false;
+    }
+
+    SectorValidatePage(page_recs_[i], &dst, i);
+
+    // Ensure that the transfer ended up with correct data.
+    if (strict) {
+      // Record page index currently CRC checked.
+      crc_page_ = i;
+      int errors = CrcCheckPage(&dst);
+      if (errors) {
+        logprintf(5, "Log: file miscompare at block %d, "
+                  "offset %x-%x. File: %s\n",
+                  i, i * page_length, ((i + 1) * page_length) - 1,
+                  filename_.c_str());
+        result = false;
+      }
+      crc_page_ = -1;
+      errorcount_ += errors;
+    }
+    if (!PutValidPage(&dst))
+      return false;
+  }
+  return result;
+}
+
+// File IO work loop. Execute until marked done.
+bool FileThread::Work() {
+  bool result = true;
+  int64 loops = 0;
+
+  logprintf(9, "Log: Starting file thread %d, file %s, device %s\n",
+            thread_num_,
+            filename_.c_str(),
+            devicename_.c_str());
+
+  if (!PagePrepare()) {
+    status_ = false;
+    return false;
+  }
+
+  // Open the data IO file.
+  int fd = 0;
+  if (!OpenFile(&fd)) {
+    status_ = false;
+    return false;
+  }
+
+  pass_ = 0;
+
+  // Load patterns into page records.
+  page_recs_ = new struct PageRec[sat_->disk_pages()];
+  for (int i = 0; i < sat_->disk_pages(); i++) {
+    page_recs_[i].pattern = new struct Pattern();
+  }
+
+  // Loop until done.
+  while (IsReadyToRun()) {
+    // Do the file write.
+    if (!(result = result && WritePages(fd)))
+      break;
+
+    // Do the file read.
+    if (!(result = result && ReadPages(fd)))
+      break;
+
+    loops++;
+    pass_ = loops;
+  }
+
+  pages_copied_ = loops * sat_->disk_pages();
+
+  // Clean up.
+  CloseFile(fd);
+  PageTeardown();
+
+  logprintf(9, "Log: Completed %d: file thread status %d, %d pages copied\n",
+            thread_num_, status_, pages_copied_);
+  // Failure to read from device indicates hardware,
+  // rather than procedural SW error.
+  status_ = true;
+  return true;
+}
+
+bool NetworkThread::IsNetworkStopSet() {
+  return !IsReadyToRunNoPause();
+}
+
+bool NetworkSlaveThread::IsNetworkStopSet() {
+  // This thread has no completion status.
+  // It finishes whever there is no more data to be
+  // passed back.
+  return true;
+}
+
+// Set ip name to use for Network IO.
+void NetworkThread::SetIP(const char *ipaddr_init) {
+  strncpy(ipaddr_, ipaddr_init, 256);
+}
+
+// Create a socket.
+// Return 0 on error.
+bool NetworkThread::CreateSocket(int *psocket) {
+  int sock = socket(AF_INET, SOCK_STREAM, 0);
+  if (sock == -1) {
+    logprintf(0, "Process Error: Cannot open socket\n");
+    pages_copied_ = 0;
+    status_ = false;
+    return false;
+  }
+  *psocket = sock;
+  return true;
+}
+
+// Close the socket.
+bool NetworkThread::CloseSocket(int sock) {
+  close(sock);
+  return true;
+}
+
+// Initiate the tcp connection.
+bool NetworkThread::Connect(int sock) {
+  struct sockaddr_in dest_addr;
+  dest_addr.sin_family = AF_INET;
+  dest_addr.sin_port = htons(kNetworkPort);
+  memset(&(dest_addr.sin_zero), '\0', sizeof(dest_addr.sin_zero));
+
+  // Translate dot notation to u32.
+  if (inet_aton(ipaddr_, &dest_addr.sin_addr) == 0) {
+    logprintf(0, "Process Error: Cannot resolve %s\n", ipaddr_);
+    pages_copied_ = 0;
+    status_ = false;
+    return false;
+  }
+
+  if (-1 == connect(sock, reinterpret_cast<struct sockaddr *>(&dest_addr),
+                    sizeof(struct sockaddr))) {
+    logprintf(0, "Process Error: Cannot connect %s\n", ipaddr_);
+    pages_copied_ = 0;
+    status_ = false;
+    return false;
+  }
+  return true;
+}
+
+// Initiate the tcp connection.
+bool NetworkListenThread::Listen() {
+  struct sockaddr_in sa;
+
+  memset(&(sa.sin_zero), '\0', sizeof(sa.sin_zero));
+
+  sa.sin_family = AF_INET;
+  sa.sin_addr.s_addr = INADDR_ANY;
+  sa.sin_port = htons(kNetworkPort);
+
+  if (-1 == bind(sock_, (struct sockaddr*)&sa, sizeof(struct sockaddr))) {
+    char buf[256];
+    sat_strerror(errno, buf, sizeof(buf));
+    logprintf(0, "Process Error: Cannot bind socket: %s\n", buf);
+    pages_copied_ = 0;
+    status_ = false;
+    return false;
+  }
+  listen(sock_, 3);
+  return true;
+}
+
+// Wait for a connection from a network traffic generation thread.
+bool NetworkListenThread::Wait() {
+    fd_set rfds;
+    struct timeval tv;
+    int retval;
+
+    // Watch sock_ to see when it has input.
+    FD_ZERO(&rfds);
+    FD_SET(sock_, &rfds);
+    // Wait up to five seconds.
+    tv.tv_sec = 5;
+    tv.tv_usec = 0;
+
+    retval = select(sock_ + 1, &rfds, NULL, NULL, &tv);
+
+    return (retval > 0);
+}
+
+// Wait for a connection from a network traffic generation thread.
+bool NetworkListenThread::GetConnection(int *pnewsock) {
+  struct sockaddr_in sa;
+  socklen_t size = sizeof(struct sockaddr_in);
+
+  int newsock = accept(sock_, reinterpret_cast<struct sockaddr *>(&sa), &size);
+  if (newsock < 0)  {
+    logprintf(0, "Process Error: Did not receive connection\n");
+    pages_copied_ = 0;
+    status_ = false;
+    return false;
+  }
+  *pnewsock = newsock;
+  return true;
+}
+
+// Send a page, return false if a page was not sent.
+bool NetworkThread::SendPage(int sock, struct page_entry *src) {
+  int page_length = sat_->page_length();
+  char *address = static_cast<char*>(src->addr);
+
+  // Send our data over the network.
+  int size = page_length;
+  while (size) {
+    int transferred = send(sock, address + (page_length - size), size, 0);
+    if ((transferred == 0) || (transferred == -1)) {
+      if (!IsNetworkStopSet()) {
+        char buf[256] = "";
+        sat_strerror(errno, buf, sizeof(buf));
+        logprintf(0, "Process Error: Thread %d, "
+                     "Network write failed, bailing. (%s)\n",
+                  thread_num_, buf);
+        status_ = false;
+      }
+      return false;
+    }
+    size = size - transferred;
+  }
+  return true;
+}
+
+// Receive a page. Return false if a page was not received.
+bool NetworkThread::ReceivePage(int sock, struct page_entry *dst) {
+  int page_length = sat_->page_length();
+  char *address = static_cast<char*>(dst->addr);
+
+  // Maybe we will get our data back again, maybe not.
+  int size = page_length;
+  while (size) {
+    int transferred = recv(sock, address + (page_length - size), size, 0);
+    if ((transferred == 0) || (transferred == -1)) {
+      // Typically network slave thread should exit as network master
+      // thread stops sending data.
+      if (IsNetworkStopSet()) {
+        int err = errno;
+        if (transferred == 0 && err == 0) {
+          // Two system setups will not sync exactly,
+          // allow early exit, but log it.
+          logprintf(0, "Log: Net thread did not receive any data, exiting.\n");
+        } else {
+          char buf[256] = "";
+          sat_strerror(err, buf, sizeof(buf));
+          // Print why we failed.
+          logprintf(0, "Process Error: Thread %d, "
+                       "Network read failed, bailing (%s).\n",
+                    thread_num_, buf);
+          status_ = false;
+          // Print arguments and results.
+          logprintf(0, "Log: recv(%d, address %x, size %x, 0) == %x, err %d\n",
+                    sock, address + (page_length - size),
+                    size, transferred, err);
+          if ((transferred == 0) &&
+              (page_length - size < 512) &&
+              (page_length - size > 0)) {
+            // Print null terminated data received, to see who's been
+            // sending us supicious unwanted data.
+            address[page_length - size] = 0;
+            logprintf(0, "Log: received  %d bytes: '%s'\n",
+                      page_length - size, address);
+          }
+        }
+      }
+      return false;
+    }
+    size = size - transferred;
+  }
+  return true;
+}
+
+// Network IO work loop. Execute until marked done.
+// Return true if the thread ran as expected.
+bool NetworkThread::Work() {
+  logprintf(9, "Log: Starting network thread %d, ip %s\n",
+            thread_num_,
+            ipaddr_);
+
+  // Make a socket.
+  int sock = 0;
+  if (!CreateSocket(&sock))
+    return false;
+
+  // Network IO loop requires network slave thread to have already initialized.
+  // We will sleep here for awhile to ensure that the slave thread will be
+  // listening by the time we connect.
+  // Sleep for 15 seconds.
+  sat_sleep(15);
+  logprintf(9, "Log: Starting execution of network thread %d, ip %s\n",
+            thread_num_,
+            ipaddr_);
+
+
+  // Connect to a slave thread.
+  if (!Connect(sock))
+    return false;
+
+  // Loop until done.
+  bool result = true;
+  int strict = sat_->strict();
+  int64 loops = 0;
+  while (IsReadyToRun()) {
+    struct page_entry src;
+    struct page_entry dst;
+    result = result && sat_->GetValid(&src);
+    result = result && sat_->GetEmpty(&dst);
+    if (!result) {
+      logprintf(0, "Process Error: net_thread failed to pop pages, "
+                "bailing\n");
+      break;
+    }
+
+    // Check data correctness.
+    if (strict)
+      CrcCheckPage(&src);
+
+    // Do the network write.
+    if (!(result = result && SendPage(sock, &src)))
+      break;
+
+    // Update pattern reference to reflect new contents.
+    dst.pattern = src.pattern;
+
+    // Do the network read.
+    if (!(result = result && ReceivePage(sock, &dst)))
+      break;
+
+    // Ensure that the transfer ended up with correct data.
+    if (strict)
+      CrcCheckPage(&dst);
+
+    // Return all of our pages to the queue.
+    result = result && sat_->PutValid(&dst);
+    result = result && sat_->PutEmpty(&src);
+    if (!result) {
+      logprintf(0, "Process Error: net_thread failed to push pages, "
+                "bailing\n");
+      break;
+    }
+    loops++;
+  }
+
+  pages_copied_ = loops;
+  status_ = result;
+
+  // Clean up.
+  CloseSocket(sock);
+
+  logprintf(9, "Log: Completed %d: network thread status %d, "
+               "%d pages copied\n",
+            thread_num_, status_, pages_copied_);
+  return result;
+}
+
+// Spawn slave threads for incoming connections.
+bool NetworkListenThread::SpawnSlave(int newsock, int threadid) {
+  logprintf(12, "Log: Listen thread spawning slave\n");
+
+  // Spawn slave thread, to reflect network traffic back to sender.
+  ChildWorker *child_worker = new ChildWorker;
+  child_worker->thread.SetSock(newsock);
+  child_worker->thread.InitThread(threadid, sat_, os_, patternlist_,
+                                  &child_worker->status);
+  child_worker->status.Initialize();
+  child_worker->thread.SpawnThread();
+  child_workers_.push_back(child_worker);
+
+  return true;
+}
+
+// Reap slave threads.
+bool NetworkListenThread::ReapSlaves() {
+  bool result = true;
+  // Gather status and reap threads.
+  logprintf(12, "Log: Joining all outstanding threads\n");
+
+  for (size_t i = 0; i < child_workers_.size(); i++) {
+    NetworkSlaveThread& child_thread = child_workers_[i]->thread;
+    logprintf(12, "Log: Joining slave thread %d\n", i);
+    child_thread.JoinThread();
+    if (child_thread.GetStatus() != 1) {
+      logprintf(0, "Process Error: Slave Thread %d failed with status %d\n", i,
+                child_thread.GetStatus());
+      result = false;
+    }
+    errorcount_ += child_thread.GetErrorCount();
+    logprintf(9, "Log: Slave Thread %d found %lld miscompares\n", i,
+              child_thread.GetErrorCount());
+    pages_copied_ += child_thread.GetPageCount();
+  }
+
+  return result;
+}
+
+// Network listener IO work loop. Execute until marked done.
+// Return false on fatal software error.
+bool NetworkListenThread::Work() {
+  logprintf(9, "Log: Starting network listen thread %d\n",
+            thread_num_);
+
+  // Make a socket.
+  sock_ = 0;
+  if (!CreateSocket(&sock_)) {
+    status_ = false;
+    return false;
+  }
+  logprintf(9, "Log: Listen thread created sock\n");
+
+  // Allows incoming connections to be queued up by socket library.
+  int newsock = 0;
+  Listen();
+  logprintf(12, "Log: Listen thread waiting for incoming connections\n");
+
+  // Wait on incoming connections, and spawn worker threads for them.
+  int threadcount = 0;
+  while (IsReadyToRun()) {
+    // Poll for connections that we can accept().
+    if (Wait()) {
+      // Accept those connections.
+      logprintf(12, "Log: Listen thread found incoming connection\n");
+      if (GetConnection(&newsock)) {
+        SpawnSlave(newsock, threadcount);
+        threadcount++;
+      }
+    }
+  }
+
+  // Gather status and join spawned threads.
+  ReapSlaves();
+
+  // Delete the child workers.
+  for (ChildVector::iterator it = child_workers_.begin();
+       it != child_workers_.end(); ++it) {
+    (*it)->status.Destroy();
+    delete *it;
+  }
+  child_workers_.clear();
+
+  CloseSocket(sock_);
+
+  status_ = true;
+  logprintf(9,
+            "Log: Completed %d: network listen thread status %d, "
+            "%d pages copied\n",
+            thread_num_, status_, pages_copied_);
+  return true;
+}
+
+// Set network reflector socket struct.
+void NetworkSlaveThread::SetSock(int sock) {
+  sock_ = sock;
+}
+
+// Network reflector IO work loop. Execute until marked done.
+// Return false on fatal software error.
+bool NetworkSlaveThread::Work() {
+  logprintf(9, "Log: Starting network slave thread %d\n",
+            thread_num_);
+
+  // Verify that we have a socket.
+  int sock = sock_;
+  if (!sock) {
+    status_ = false;
+    return false;
+  }
+
+  // Loop until done.
+  int64 loops = 0;
+  // Init a local buffer for storing data.
+  void *local_page = NULL;
+  int result = posix_memalign(&local_page, 512, sat_->page_length());
+  if (result) {
+    logprintf(0, "Process Error: net slave posix_memalign "
+                 "returned %d (fail)\n",
+              result);
+    status_ = false;
+    return false;
+  }
+
+  struct page_entry page;
+  page.addr = local_page;
+
+  // This thread will continue to run as long as the thread on the other end of
+  // the socket is still sending and receiving data.
+  while (1) {
+    // Do the network read.
+    if (!ReceivePage(sock, &page))
+      break;
+
+    // Do the network write.
+    if (!SendPage(sock, &page))
+      break;
+
+    loops++;
+  }
+
+  pages_copied_ = loops;
+  // No results provided from this type of thread.
+  status_ = true;
+
+  // Clean up.
+  CloseSocket(sock);
+
+  logprintf(9,
+            "Log: Completed %d: network slave thread status %d, "
+            "%d pages copied\n",
+            thread_num_, status_, pages_copied_);
+  return true;
+}
+
+// Thread work loop. Execute until marked finished.
+bool ErrorPollThread::Work() {
+  logprintf(9, "Log: Starting system error poll thread %d\n", thread_num_);
+
+  // This calls a generic error polling function in the Os abstraction layer.
+  do {
+    errorcount_ += os_->ErrorPoll();
+    os_->ErrorWait();
+  } while (IsReadyToRun());
+
+  logprintf(9, "Log: Finished system error poll thread %d: %d errors\n",
+            thread_num_, errorcount_);
+  status_ = true;
+  return true;
+}
+
+// Worker thread to heat up CPU.
+// This thread does not evaluate pass/fail or software error.
+bool CpuStressThread::Work() {
+  logprintf(9, "Log: Starting CPU stress thread %d\n", thread_num_);
+
+  do {
+    // Run ludloff's platform/CPU-specific assembly workload.
+    os_->CpuStressWorkload();
+    YieldSelf();
+  } while (IsReadyToRun());
+
+  logprintf(9, "Log: Finished CPU stress thread %d:\n",
+            thread_num_);
+  status_ = true;
+  return true;
+}
+
+CpuCacheCoherencyThread::CpuCacheCoherencyThread(cc_cacheline_data *data,
+                                                 int cacheline_count,
+                                                 int thread_num,
+                                                 int inc_count) {
+  cc_cacheline_data_ = data;
+  cc_cacheline_count_ = cacheline_count;
+  cc_thread_num_ = thread_num;
+  cc_inc_count_ = inc_count;
+}
+
+// Worked thread to test the cache coherency of the CPUs
+// Return false on fatal sw error.
+bool CpuCacheCoherencyThread::Work() {
+  logprintf(9, "Log: Starting the Cache Coherency thread %d\n",
+            cc_thread_num_);
+  uint64 time_start, time_end;
+  struct timeval tv;
+
+  unsigned int seed = static_cast<unsigned int>(gettid());
+  gettimeofday(&tv, NULL);  // Get the timestamp before increments.
+  time_start = tv.tv_sec * 1000000ULL + tv.tv_usec;
+
+  uint64 total_inc = 0;  // Total increments done by the thread.
+  while (IsReadyToRun()) {
+    for (int i = 0; i < cc_inc_count_; i++) {
+      // Choose a datastructure in random and increment the appropriate
+      // member in that according to the offset (which is the same as the
+      // thread number.
+      int r = rand_r(&seed);
+      r = cc_cacheline_count_ * (r / (RAND_MAX + 1.0));
+      // Increment the member of the randomely selected structure.
+      (cc_cacheline_data_[r].num[cc_thread_num_])++;
+    }
+
+    total_inc += cc_inc_count_;
+
+    // Calculate if the local counter matches with the global value
+    // in all the cache line structures for this particular thread.
+    int cc_global_num = 0;
+    for (int cline_num = 0; cline_num < cc_cacheline_count_; cline_num++) {
+      cc_global_num += cc_cacheline_data_[cline_num].num[cc_thread_num_];
+      // Reset the cachline member's value for the next run.
+      cc_cacheline_data_[cline_num].num[cc_thread_num_] = 0;
+    }
+    if (sat_->error_injection())
+      cc_global_num = -1;
+
+    if (cc_global_num != cc_inc_count_) {
+      errorcount_++;
+      logprintf(0, "Hardware Error: global(%d) and local(%d) do not match\n",
+                cc_global_num, cc_inc_count_);
+    }
+  }
+  gettimeofday(&tv, NULL);  // Get the timestamp at the end.
+  time_end = tv.tv_sec * 1000000ULL + tv.tv_usec;
+
+  uint64 us_elapsed = time_end - time_start;
+  // inc_rate is the no. of increments per second.
+  double inc_rate = total_inc * 1e6 / us_elapsed;
+
+  logprintf(4, "Stats: CC Thread(%d): Time=%llu us,"
+            " Increments=%llu, Increments/sec = %.6lf\n",
+            cc_thread_num_, us_elapsed, total_inc, inc_rate);
+  logprintf(9, "Log: Finished CPU Cache Coherency thread %d:\n",
+            cc_thread_num_);
+  status_ = true;
+  return true;
+}
+
+DiskThread::DiskThread(DiskBlockTable *block_table) {
+  read_block_size_ = kSectorSize;   // default 1 sector (512 bytes)
+  write_block_size_ = kSectorSize;  // this assumes read and write block size
+                                    // are the same
+  segment_size_ = -1;               // use the entire disk as one segment
+  cache_size_ = 16 * 1024 * 1024;   // assume 16MiB cache by default
+  // Use a queue such that 3/2 times as much data as the cache can hold
+  // is written before it is read so that there is little chance the read
+  // data is in the cache.
+  queue_size_ = ((cache_size_ / write_block_size_) * 3) / 2;
+  blocks_per_segment_ = 32;
+
+  read_threshold_ = 100000;         // 100ms is a reasonable limit for
+  write_threshold_ = 100000;        // reading/writing a sector
+
+  read_timeout_ = 5000000;          // 5 seconds should be long enough for a
+  write_timeout_ = 5000000;         // timout for reading/writing
+
+  device_sectors_ = 0;
+  non_destructive_ = 0;
+
+  aio_ctx_ = 0;
+  block_table_ = block_table;
+  update_block_table_ = 1;
+
+  block_buffer_ = NULL;
+
+  blocks_written_ = 0;
+  blocks_read_ = 0;
+}
+
+DiskThread::~DiskThread() {
+  if (block_buffer_)
+    free(block_buffer_);
+}
+
+// Set filename for device file (in /dev).
+void DiskThread::SetDevice(const char *device_name) {
+  device_name_ = device_name;
+}
+
+// Set various parameters that control the behaviour of the test.
+// -1 is used as a sentinel value on each parameter (except non_destructive)
+// to indicate that the parameter not be set.
+bool DiskThread::SetParameters(int read_block_size,
+                               int write_block_size,
+                               int64 segment_size,
+                               int64 cache_size,
+                               int blocks_per_segment,
+                               int64 read_threshold,
+                               int64 write_threshold,
+                               int non_destructive) {
+  if (read_block_size != -1) {
+    // Blocks must be aligned to the disk's sector size.
+    if (read_block_size % kSectorSize != 0) {
+      logprintf(0, "Process Error: Block size must be a multiple of %d "
+                "(thread %d).\n", kSectorSize, thread_num_);
+      return false;
+    }
+
+    read_block_size_ = read_block_size;
+  }
+
+  if (write_block_size != -1) {
+    // Write blocks must be aligned to the disk's sector size and to the
+    // block size.
+    if (write_block_size % kSectorSize != 0) {
+      logprintf(0, "Process Error: Write block size must be a multiple "
+                "of %d (thread %d).\n", kSectorSize, thread_num_);
+      return false;
+    }
+    if (write_block_size % read_block_size_ != 0) {
+      logprintf(0, "Process Error: Write block size must be a multiple "
+                "of the read block size, which is %d (thread %d).\n",
+                read_block_size_, thread_num_);
+      return false;
+    }
+
+    write_block_size_ = write_block_size;
+
+  } else {
+    // Make sure write_block_size_ is still valid.
+    if (read_block_size_ > write_block_size_) {
+      logprintf(5, "Log: Assuming write block size equal to read block size, "
+                "which is %d (thread %d).\n", read_block_size_,
+                thread_num_);
+      write_block_size_ = read_block_size_;
+    } else {
+      if (write_block_size_ % read_block_size_ != 0) {
+        logprintf(0, "Process Error: Write block size (defined as %d) must "
+                  "be a multiple of the read block size, which is %d "
+                  "(thread %d).\n", write_block_size_, read_block_size_,
+                  thread_num_);
+        return false;
+      }
+    }
+  }
+
+  if (cache_size != -1) {
+    cache_size_ = cache_size;
+  }
+
+  if (blocks_per_segment != -1) {
+    if (blocks_per_segment <= 0) {
+      logprintf(0, "Process Error: Blocks per segment must be greater than "
+                   "zero.\n (thread %d)", thread_num_);
+      return false;
+    }
+
+    blocks_per_segment_ = blocks_per_segment;
+  }
+
+  if (read_threshold != -1) {
+    if (read_threshold <= 0) {
+      logprintf(0, "Process Error: Read threshold must be greater than "
+                   "zero (thread %d).\n", thread_num_);
+      return false;
+    }
+
+    read_threshold_ = read_threshold;
+  }
+
+  if (write_threshold != -1) {
+    if (write_threshold <= 0) {
+      logprintf(0, "Process Error: Write threshold must be greater than "
+                   "zero (thread %d).\n", thread_num_);
+      return false;
+    }
+
+    write_threshold_ = write_threshold;
+  }
+
+  if (segment_size != -1) {
+    // Segments must be aligned to the disk's sector size.
+    if (segment_size % kSectorSize != 0) {
+      logprintf(0, "Process Error: Segment size must be a multiple of %d"
+                " (thread %d).\n", kSectorSize, thread_num_);
+      return false;
+    }
+
+    segment_size_ = segment_size / kSectorSize;
+  }
+
+  non_destructive_ = non_destructive;
+
+  // Having a queue of 150% of blocks that will fit in the disk's cache
+  // should be enough to force out the oldest block before it is read and hence,
+  // making sure the data comes form the disk and not the cache.
+  queue_size_ = ((cache_size_ / write_block_size_) * 3) / 2;
+  // Updating DiskBlockTable parameters
+  if (update_block_table_) {
+    block_table_->SetParameters(kSectorSize, write_block_size_,
+                                device_sectors_, segment_size_,
+                                device_name_);
+  }
+  return true;
+}
+
+// Open a device, return false on failure.
+bool DiskThread::OpenDevice(int *pfile) {
+  int fd = open(device_name_.c_str(),
+                O_RDWR | O_SYNC | O_DIRECT | O_LARGEFILE,
+                0);
+  if (fd < 0) {
+    logprintf(0, "Process Error: Failed to open device %s (thread %d)!!\n",
+              device_name_.c_str(), thread_num_);
+    return false;
+  }
+  *pfile = fd;
+
+  return GetDiskSize(fd);
+}
+
+// Retrieves the size (in bytes) of the disk/file.
+// Return false on failure.
+bool DiskThread::GetDiskSize(int fd) {
+  struct stat device_stat;
+  if (fstat(fd, &device_stat) == -1) {
+    logprintf(0, "Process Error: Unable to fstat disk %s (thread %d).\n",
+              device_name_.c_str(), thread_num_);
+    return false;
+  }
+
+  // For a block device, an ioctl is needed to get the size since the size
+  // of the device file (i.e. /dev/sdb) is 0.
+  if (S_ISBLK(device_stat.st_mode)) {
+    uint64 block_size = 0;
+
+    if (ioctl(fd, BLKGETSIZE64, &block_size) == -1) {
+      logprintf(0, "Process Error: Unable to ioctl disk %s (thread %d).\n",
+                device_name_.c_str(), thread_num_);
+      return false;
+    }
+
+    // Zero size indicates nonworking device..
+    if (block_size == 0) {
+      os_->ErrorReport(device_name_.c_str(), "device-size-zero", 1);
+      ++errorcount_;
+      status_ = true;  // Avoid a procedural error.
+      return false;
+    }
+
+    device_sectors_ = block_size / kSectorSize;
+
+  } else if (S_ISREG(device_stat.st_mode)) {
+    device_sectors_ = device_stat.st_size / kSectorSize;
+
+  } else {
+    logprintf(0, "Process Error: %s is not a regular file or block "
+              "device (thread %d).\n", device_name_.c_str(),
+              thread_num_);
+    return false;
+  }
+
+  logprintf(12, "Log: Device sectors: %lld on disk %s (thread %d).\n",
+            device_sectors_, device_name_.c_str(), thread_num_);
+
+  if (update_block_table_) {
+    block_table_->SetParameters(kSectorSize, write_block_size_,
+                                device_sectors_, segment_size_,
+                                device_name_);
+  }
+
+  return true;
+}
+
+bool DiskThread::CloseDevice(int fd) {
+  close(fd);
+  return true;
+}
+
+// Return the time in microseconds.
+int64 DiskThread::GetTime() {
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+  return tv.tv_sec * 1000000 + tv.tv_usec;
+}
+
+// Do randomized reads and (possibly) writes on a device.
+// Return false on fatal SW error, true on SW success,
+// regardless of whether HW failed.
+bool DiskThread::DoWork(int fd) {
+  int64 block_num = 0;
+  int64 num_segments;
+
+  if (segment_size_ == -1) {
+    num_segments = 1;
+  } else {
+    num_segments = device_sectors_ / segment_size_;
+    if (device_sectors_ % segment_size_ != 0)
+      num_segments++;
+  }
+
+  // Disk size should be at least 3x cache size.  See comment later for
+  // details.
+  sat_assert(device_sectors_ * kSectorSize > 3 * cache_size_);
+
+  // This disk test works by writing blocks with a certain pattern to
+  // disk, then reading them back and verifying it against the pattern
+  // at a later time.  A failure happens when either the block cannot
+  // be written/read or when the read block is different than what was
+  // written.  If a block takes too long to write/read, then a warning
+  // is given instead of an error since taking too long is not
+  // necessarily an error.
+  //
+  // To prevent the read blocks from coming from the disk cache,
+  // enough blocks are written before read such that a block would
+  // be ejected from the disk cache by the time it is read.
+  //
+  // TODO(amistry): Implement some sort of read/write throttling.  The
+  //                flood of asynchronous I/O requests when a drive is
+  //                unplugged is causing the application and kernel to
+  //                become unresponsive.
+
+  while (IsReadyToRun()) {
+    // Write blocks to disk.
+    logprintf(16, "Log: Write phase %sfor disk %s (thread %d).\n",
+              non_destructive_ ? "(disabled) " : "",
+              device_name_.c_str(), thread_num_);
+    while (IsReadyToRunNoPause() &&
+           in_flight_sectors_.size() <
+               static_cast<size_t>(queue_size_ + 1)) {
+      // Confine testing to a particular segment of the disk.
+      int64 segment = (block_num / blocks_per_segment_) % num_segments;
+      if (!non_destructive_ &&
+          (block_num % blocks_per_segment_ == 0)) {
+        logprintf(20, "Log: Starting to write segment %lld out of "
+                  "%lld on disk %s (thread %d).\n",
+                  segment, num_segments, device_name_.c_str(),
+                  thread_num_);
+      }
+      block_num++;
+
+      BlockData *block = block_table_->GetUnusedBlock(segment);
+
+      // If an unused sequence of sectors could not be found, skip to the
+      // next block to process.  Soon, a new segment will come and new
+      // sectors will be able to be allocated.  This effectively puts a
+      // minumim on the disk size at 3x the stated cache size, or 48MiB
+      // if a cache size is not given (since the cache is set as 16MiB
+      // by default).  Given that todays caches are at the low MiB range
+      // and drive sizes at the mid GB, this shouldn't pose a problem.
+      // The 3x minimum comes from the following:
+      //   1. In order to allocate 'y' blocks from a segment, the
+      //      segment must contain at least 2y blocks or else an
+      //      allocation may not succeed.
+      //   2. Assume the entire disk is one segment.
+      //   3. A full write phase consists of writing blocks corresponding to
+      //      3/2 cache size.
+      //   4. Therefore, the one segment must have 2 * 3/2 * cache
+      //      size worth of blocks = 3 * cache size worth of blocks
+      //      to complete.
+      // In non-destructive mode, don't write anything to disk.
+      if (!non_destructive_) {
+        if (!WriteBlockToDisk(fd, block)) {
+          block_table_->RemoveBlock(block);
+          return true;
+        }
+        blocks_written_++;
+      }
+
+      // Block is either initialized by writing, or in nondestructive case,
+      // initialized by being added into the datastructure for later reading.
+      block->SetBlockAsInitialized();
+
+      in_flight_sectors_.push(block);
+    }
+
+    // Verify blocks on disk.
+    logprintf(20, "Log: Read phase for disk %s (thread %d).\n",
+              device_name_.c_str(), thread_num_);
+    while (IsReadyToRunNoPause() && !in_flight_sectors_.empty()) {
+      BlockData *block = in_flight_sectors_.front();
+      in_flight_sectors_.pop();
+      if (!ValidateBlockOnDisk(fd, block))
+        return true;
+      block_table_->RemoveBlock(block);
+      blocks_read_++;
+    }
+  }
+
+  pages_copied_ = blocks_written_ + blocks_read_;
+  return true;
+}
+
+// Do an asynchronous disk I/O operation.
+// Return false if the IO is not set up.
+bool DiskThread::AsyncDiskIO(IoOp op, int fd, void *buf, int64 size,
+                            int64 offset, int64 timeout) {
+  // Use the Linux native asynchronous I/O interface for reading/writing.
+  // A read/write consists of three basic steps:
+  //    1. create an io context.
+  //    2. prepare and submit an io request to the context
+  //    3. wait for an event on the context.
+
+  struct {
+    const int opcode;
+    const char *op_str;
+    const char *error_str;
+  } operations[2] = {
+    { IO_CMD_PREAD, "read", "disk-read-error" },
+    { IO_CMD_PWRITE, "write", "disk-write-error" }
+  };
+
+  struct iocb cb;
+  memset(&cb, 0, sizeof(cb));
+
+  cb.aio_fildes = fd;
+  cb.aio_lio_opcode = operations[op].opcode;
+  cb.u.c.buf = buf;
+  cb.u.c.nbytes = size;
+  cb.u.c.offset = offset;
+
+  struct iocb *cbs[] = { &cb };
+  if (io_submit(aio_ctx_, 1, cbs) != 1) {
+    int error = errno;
+    char buf[256];
+    sat_strerror(error, buf, sizeof(buf));
+    logprintf(0, "Process Error: Unable to submit async %s "
+                 "on disk %s (thread %d). Error %d, %s\n",
+              operations[op].op_str, device_name_.c_str(),
+              thread_num_, error, buf);
+    return false;
+  }
+
+  struct io_event event;
+  memset(&event, 0, sizeof(event));
+  struct timespec tv;
+  tv.tv_sec = timeout / 1000000;
+  tv.tv_nsec = (timeout % 1000000) * 1000;
+  if (io_getevents(aio_ctx_, 1, 1, &event, &tv) != 1) {
+    // A ctrl-c from the keyboard will cause io_getevents to fail with an
+    // EINTR error code.  This is not an error and so don't treat it as such,
+    // but still log it.
+    int error = errno;
+    if (error == EINTR) {
+      logprintf(5, "Log: %s interrupted on disk %s (thread %d).\n",
+                operations[op].op_str, device_name_.c_str(),
+                thread_num_);
+    } else {
+      os_->ErrorReport(device_name_.c_str(), operations[op].error_str, 1);
+      errorcount_ += 1;
+      logprintf(0, "Hardware Error: Timeout doing async %s to sectors "
+                   "starting at %lld on disk %s (thread %d).\n",
+                operations[op].op_str, offset / kSectorSize,
+                device_name_.c_str(), thread_num_);
+    }
+
+    // Don't bother checking return codes since io_cancel seems to always fail.
+    // Since io_cancel is always failing, destroying and recreating an I/O
+    // context is a workaround for canceling an in-progress I/O operation.
+    // TODO(amistry): Find out why io_cancel isn't working and make it work.
+    io_cancel(aio_ctx_, &cb, &event);
+    io_destroy(aio_ctx_);
+    aio_ctx_ = 0;
+    if (io_setup(5, &aio_ctx_)) {
+      int error = errno;
+      char buf[256];
+      sat_strerror(error, buf, sizeof(buf));
+      logprintf(0, "Process Error: Unable to create aio context on disk %s"
+                " (thread %d) Error %d, %s\n",
+                device_name_.c_str(), thread_num_, error, buf);
+    }
+
+    return false;
+  }
+
+  // event.res contains the number of bytes written/read or
+  // error if < 0, I think.
+  if (event.res != static_cast<uint64>(size)) {
+    errorcount_++;
+    os_->ErrorReport(device_name_.c_str(), operations[op].error_str, 1);
+
+    if (event.res < 0) {
+      switch (event.res) {
+        case -EIO:
+          logprintf(0, "Hardware Error: Low-level I/O error while doing %s to "
+                       "sectors starting at %lld on disk %s (thread %d).\n",
+                    operations[op].op_str, offset / kSectorSize,
+                    device_name_.c_str(), thread_num_);
+          break;
+        default:
+          logprintf(0, "Hardware Error: Unknown error while doing %s to "
+                       "sectors starting at %lld on disk %s (thread %d).\n",
+                    operations[op].op_str, offset / kSectorSize,
+                    device_name_.c_str(), thread_num_);
+      }
+    } else {
+      logprintf(0, "Hardware Error: Unable to %s to sectors starting at "
+                   "%lld on disk %s (thread %d).\n",
+                operations[op].op_str, offset / kSectorSize,
+                device_name_.c_str(), thread_num_);
+    }
+    return false;
+  }
+
+  return true;
+}
+
+// Write a block to disk.
+// Return false if the block is not written.
+bool DiskThread::WriteBlockToDisk(int fd, BlockData *block) {
+  memset(block_buffer_, 0, block->GetSize());
+
+  // Fill block buffer with a pattern
+  struct page_entry pe;
+  if (!sat_->GetValid(&pe)) {
+    // Even though a valid page could not be obatined, it is not an error
+    // since we can always fill in a pattern directly, albeit slower.
+    unsigned int *memblock = static_cast<unsigned int *>(block_buffer_);
+    block->SetPattern(patternlist_->GetRandomPattern());
+
+    logprintf(11, "Log: Warning, using pattern fill fallback in "
+                  "DiskThread::WriteBlockToDisk on disk %s (thread %d).\n",
+              device_name_.c_str(), thread_num_);
+
+    for (int i = 0; i < block->GetSize()/wordsize_; i++) {
+      memblock[i] = block->GetPattern()->pattern(i);
+    }
+  } else {
+    memcpy(block_buffer_, pe.addr, block->GetSize());
+    block->SetPattern(pe.pattern);
+    sat_->PutValid(&pe);
+  }
+
+  logprintf(12, "Log: Writing %lld sectors starting at %lld on disk %s"
+            " (thread %d).\n",
+            block->GetSize()/kSectorSize, block->GetAddress(),
+            device_name_.c_str(), thread_num_);
+
+  int64 start_time = GetTime();
+
+  if (!AsyncDiskIO(ASYNC_IO_WRITE, fd, block_buffer_, block->GetSize(),
+                   block->GetAddress() * kSectorSize, write_timeout_)) {
+    return false;
+  }
+
+  int64 end_time = GetTime();
+  logprintf(12, "Log: Writing time: %lld us (thread %d).\n",
+            end_time - start_time, thread_num_);
+  if (end_time - start_time > write_threshold_) {
+    logprintf(5, "Log: Write took %lld us which is longer than threshold "
+                 "%lld us on disk %s (thread %d).\n",
+              end_time - start_time, write_threshold_, device_name_.c_str(),
+              thread_num_);
+  }
+
+  return true;
+}
+
+// Verify a block on disk.
+// Return true if the block was read, also increment errorcount
+// if the block had data errors or performance problems.
+bool DiskThread::ValidateBlockOnDisk(int fd, BlockData *block) {
+  int64 blocks = block->GetSize() / read_block_size_;
+  int64 bytes_read = 0;
+  int64 current_blocks;
+  int64 current_bytes;
+  uint64 address = block->GetAddress();
+
+  logprintf(20, "Log: Reading sectors starting at %lld on disk %s "
+            "(thread %d).\n",
+            address, device_name_.c_str(), thread_num_);
+
+  // Read block from disk and time the read.  If it takes longer than the
+  // threshold, complain.
+  if (lseek64(fd, address * kSectorSize, SEEK_SET) == -1) {
+    logprintf(0, "Process Error: Unable to seek to sector %lld in "
+              "DiskThread::ValidateSectorsOnDisk on disk %s "
+              "(thread %d).\n", address, device_name_.c_str(), thread_num_);
+    return false;
+  }
+  int64 start_time = GetTime();
+
+  // Split a large write-sized block into small read-sized blocks and
+  // read them in groups of randomly-sized multiples of read block size.
+  // This assures all data written on disk by this particular block
+  // will be tested using a random reading pattern.
+  while (blocks != 0) {
+    // Test all read blocks in a written block.
+    current_blocks = (random() % blocks) + 1;
+    current_bytes = current_blocks * read_block_size_;
+
+    memset(block_buffer_, 0, current_bytes);
+
+    logprintf(20, "Log: Reading %lld sectors starting at sector %lld on "
+              "disk %s (thread %d)\n",
+              current_bytes / kSectorSize,
+              (address * kSectorSize + bytes_read) / kSectorSize,
+              device_name_.c_str(), thread_num_);
+
+    if (!AsyncDiskIO(ASYNC_IO_READ, fd, block_buffer_, current_bytes,
+                     address * kSectorSize + bytes_read,
+                     write_timeout_)) {
+      return false;
+    }
+
+    int64 end_time = GetTime();
+    logprintf(20, "Log: Reading time: %lld us (thread %d).\n",
+              end_time - start_time, thread_num_);
+    if (end_time - start_time > read_threshold_) {
+      logprintf(5, "Log: Read took %lld us which is longer than threshold "
+                "%lld us on disk %s (thread %d).\n",
+                end_time - start_time, read_threshold_,
+                device_name_.c_str(), thread_num_);
+    }
+
+    // In non-destructive mode, don't compare the block to the pattern since
+    // the block was never written to disk in the first place.
+    if (!non_destructive_) {
+      if (CheckRegion(block_buffer_, block->GetPattern(), current_bytes,
+                      0, bytes_read)) {
+        os_->ErrorReport(device_name_.c_str(), "disk-pattern-error", 1);
+        errorcount_ += 1;
+        logprintf(0, "Hardware Error: Pattern mismatch in block starting at "
+                  "sector %lld in DiskThread::ValidateSectorsOnDisk on "
+                  "disk %s (thread %d).\n",
+                  address, device_name_.c_str(), thread_num_);
+      }
+    }
+
+    bytes_read += current_blocks * read_block_size_;
+    blocks -= current_blocks;
+  }
+
+  return true;
+}
+
+// Direct device access thread.
+// Return false on software error.
+bool DiskThread::Work() {
+  int fd;
+
+  logprintf(9, "Log: Starting disk thread %d, disk %s\n",
+            thread_num_, device_name_.c_str());
+
+  srandom(time(NULL));
+
+  if (!OpenDevice(&fd)) {
+    status_ = false;
+    return false;
+  }
+
+  // Allocate a block buffer aligned to 512 bytes since the kernel requires it
+  // when using direst IO.
+  int memalign_result = posix_memalign(&block_buffer_, kBufferAlignment,
+                              sat_->page_length());
+  if (memalign_result) {
+    CloseDevice(fd);
+    logprintf(0, "Process Error: Unable to allocate memory for buffers "
+                 "for disk %s (thread %d) posix memalign returned %d.\n",
+              device_name_.c_str(), thread_num_, memalign_result);
+    status_ = false;
+    return false;
+  }
+
+  if (io_setup(5, &aio_ctx_)) {
+    CloseDevice(fd);
+    logprintf(0, "Process Error: Unable to create aio context for disk %s"
+              " (thread %d).\n",
+              device_name_.c_str(), thread_num_);
+    status_ = false;
+    return false;
+  }
+
+  bool result = DoWork(fd);
+
+  status_ = result;
+
+  io_destroy(aio_ctx_);
+  CloseDevice(fd);
+
+  logprintf(9, "Log: Completed %d (disk %s): disk thread status %d, "
+               "%d pages copied\n",
+            thread_num_, device_name_.c_str(), status_, pages_copied_);
+  return result;
+}
+
+RandomDiskThread::RandomDiskThread(DiskBlockTable *block_table)
+    : DiskThread(block_table) {
+  update_block_table_ = 0;
+}
+
+RandomDiskThread::~RandomDiskThread() {
+}
+
+// Workload for random disk thread.
+bool RandomDiskThread::DoWork(int fd) {
+  logprintf(11, "Log: Random phase for disk %s (thread %d).\n",
+            device_name_.c_str(), thread_num_);
+  while (IsReadyToRun()) {
+    BlockData *block = block_table_->GetRandomBlock();
+    if (block == NULL) {
+      logprintf(12, "Log: No block available for device %s (thread %d).\n",
+                device_name_.c_str(), thread_num_);
+    } else {
+      ValidateBlockOnDisk(fd, block);
+      block_table_->ReleaseBlock(block);
+      blocks_read_++;
+    }
+  }
+  pages_copied_ = blocks_read_;
+  return true;
+}
+
+MemoryRegionThread::MemoryRegionThread() {
+  error_injection_ = false;
+  pages_ = NULL;
+}
+
+MemoryRegionThread::~MemoryRegionThread() {
+  if (pages_ != NULL)
+    delete pages_;
+}
+
+// Set a region of memory or MMIO to be tested.
+// Return false if region could not be mapped.
+bool MemoryRegionThread::SetRegion(void *region, int64 size) {
+  int plength = sat_->page_length();
+  int npages = size / plength;
+  if (size % plength) {
+    logprintf(0, "Process Error: region size is not a multiple of SAT "
+              "page length\n");
+    return false;
+  } else {
+    if (pages_ != NULL)
+      delete pages_;
+    pages_ = new PageEntryQueue(npages);
+    char *base_addr = reinterpret_cast<char*>(region);
+    region_ = base_addr;
+    for (int i = 0; i < npages; i++) {
+      struct page_entry pe;
+      init_pe(&pe);
+      pe.addr = reinterpret_cast<void*>(base_addr + i * plength);
+      pe.offset = i * plength;
+
+      pages_->Push(&pe);
+    }
+    return true;
+  }
+}
+
+// More detailed error printout for hardware errors in memory or MMIO
+// regions.
+void MemoryRegionThread::ProcessError(struct ErrorRecord *error,
+                                      int priority,
+                                      const char *message) {
+  uint32 buffer_offset;
+  if (phase_ == kPhaseCopy) {
+    // If the error occurred on the Copy Phase, it means that
+    // the source data (i.e., the main memory) is wrong. so
+    // just pass it to the original ProcessError to call a
+    // bad-dimm error
+    WorkerThread::ProcessError(error, priority, message);
+  } else if (phase_ == kPhaseCheck) {
+    // A error on the Check Phase means that the memory region tested
+    // has an error. Gathering more information and then reporting
+    // the error.
+    // Determine if this is a write or read error.
+    os_->Flush(error->vaddr);
+    error->reread = *(error->vaddr);
+    char *good = reinterpret_cast<char*>(&(error->expected));
+    char *bad = reinterpret_cast<char*>(&(error->actual));
+    sat_assert(error->expected != error->actual);
+    unsigned int offset = 0;
+    for (offset = 0; offset < (sizeof(error->expected) - 1); offset++) {
+      if (good[offset] != bad[offset])
+        break;
+    }
+
+    error->vbyteaddr = reinterpret_cast<char*>(error->vaddr) + offset;
+
+    buffer_offset = error->vbyteaddr - region_;
+
+    // Find physical address if possible.
+    error->paddr = os_->VirtualToPhysical(error->vbyteaddr);
+    logprintf(priority,
+              "%s: miscompare on %s, CRC check at %p(0x%llx), "
+              "offset %llx: read:0x%016llx, reread:0x%016llx "
+              "expected:0x%016llx\n",
+              message,
+              identifier_.c_str(),
+              error->vaddr,
+              error->paddr,
+              buffer_offset,
+              error->actual,
+              error->reread,
+              error->expected);
+  } else {
+    logprintf(0, "Process Error: memory region thread raised an "
+              "unexpected error.");
+  }
+}
+
+// Workload for testion memory or MMIO regions.
+// Return false on software error.
+bool MemoryRegionThread::Work() {
+  struct page_entry source_pe;
+  struct page_entry memregion_pe;
+  bool result = true;
+  int64 loops = 0;
+  const uint64 error_constant = 0x00ba00000000ba00LL;
+
+  // For error injection.
+  int64 *addr = 0x0;
+  int offset = 0;
+  int64 data = 0;
+
+  logprintf(9, "Log: Starting Memory Region thread %d\n", thread_num_);
+
+  while (IsReadyToRun()) {
+    // Getting pages from SAT and queue.
+    phase_ = kPhaseNoPhase;
+    result = result && sat_->GetValid(&source_pe);
+    if (!result) {
+      logprintf(0, "Process Error: memory region thread failed to pop "
+                "pages from SAT, bailing\n");
+      break;
+    }
+
+    result = result && pages_->PopRandom(&memregion_pe);
+    if (!result) {
+      logprintf(0, "Process Error: memory region thread failed to pop "
+                "pages from queue, bailing\n");
+      break;
+    }
+
+    // Error injection for CRC copy.
+    if ((sat_->error_injection() || error_injection_) && loops == 1) {
+      addr = reinterpret_cast<int64*>(source_pe.addr);
+      offset = random() % (sat_->page_length() / wordsize_);
+      data = addr[offset];
+      addr[offset] = error_constant;
+    }
+
+    // Copying SAT page into memory region.
+    phase_ = kPhaseCopy;
+    CrcCopyPage(&memregion_pe, &source_pe);
+    memregion_pe.pattern = source_pe.pattern;
+
+    // Error injection for CRC Check.
+    if ((sat_->error_injection() || error_injection_) && loops == 2) {
+      addr = reinterpret_cast<int64*>(memregion_pe.addr);
+      offset = random() % (sat_->page_length() / wordsize_);
+      data = addr[offset];
+      addr[offset] = error_constant;
+    }
+
+    // Checking page content in memory region.
+    phase_ = kPhaseCheck;
+    CrcCheckPage(&memregion_pe);
+
+    phase_ = kPhaseNoPhase;
+    // Storing pages on their proper queues.
+    result = result && sat_->PutValid(&source_pe);
+    if (!result) {
+      logprintf(0, "Process Error: memory region thread failed to push "
+                "pages into SAT, bailing\n");
+      break;
+    }
+    result = result && pages_->Push(&memregion_pe);
+    if (!result) {
+      logprintf(0, "Process Error: memory region thread failed to push "
+                "pages into queue, bailing\n");
+      break;
+    }
+
+    if ((sat_->error_injection() || error_injection_) &&
+        loops >= 1 && loops <= 2) {
+      addr[offset] = data;
+    }
+
+    loops++;
+    YieldSelf();
+  }
+
+  pages_copied_ = loops;
+  status_ = result;
+  logprintf(9, "Log: Completed %d: Memory Region thread. Status %d, %d "
+            "pages checked\n", thread_num_, status_, pages_copied_);
+  return result;
+}
diff --git a/src/worker.h b/src/worker.h
new file mode 100644
index 0000000..7aae5f2
--- /dev/null
+++ b/src/worker.h
@@ -0,0 +1,804 @@
+// Copyright 2006 Google Inc. All Rights Reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//      http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// worker.h : worker thread interface
+
+// This file contains the Worker Thread class interface
+// for the SAT test. Worker Threads implement a repetative
+// task used to test or stress the system.
+
+#ifndef STRESSAPPTEST_WORKER_H_
+#define STRESSAPPTEST_WORKER_H_
+
+#include <pthread.h>
+
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include <libaio.h>
+
+#include <queue>
+#include <set>
+#include <string>
+#include <vector>
+
+// This file must work with autoconf on its public version,
+// so these includes are correct.
+#include "disk_blocks.h"
+#include "queue.h"
+#include "sattypes.h"
+
+
+// Global Datastruture shared by the Cache Coherency Worker Threads.
+struct cc_cacheline_data {
+  int *num;
+};
+
+// Typical usage:
+// (Other workflows may be possible, see function comments for details.)
+// - Control thread creates object.
+// - Control thread calls AddWorkers(1) for each worker thread.
+// - Control thread calls Initialize().
+// - Control thread launches worker threads.
+// - Every worker thread frequently calls ContinueRunning().
+// - Control thread periodically calls PauseWorkers(), effectively sleeps, and
+//     then calls ResumeWorkers().
+// - Some worker threads may exit early, before StopWorkers() is called.  They
+//     call RemoveSelf() after their last call to ContinueRunning().
+// - Control thread eventually calls StopWorkers().
+// - Worker threads exit.
+// - Control thread joins worker threads.
+// - Control thread calls Destroy().
+// - Control thread destroys object.
+//
+// Threadsafety:
+// - ContinueRunning() may be called concurrently by different workers, but not
+//     by a single worker.
+// - No other methods may ever be called concurrently, with themselves or
+//     eachother.
+// - This object may be used by multiple threads only between Initialize() and
+//     Destroy().
+//
+// TODO(matthewb): Move this class and its unittest to their own files.
+class WorkerStatus {
+ public:
+  //--------------------------------
+  // Methods for the control thread.
+  //--------------------------------
+
+  WorkerStatus() : num_workers_(0), status_(RUN) {}
+
+  // Called by the control thread to increase the worker count.  Must be called
+  // before Initialize().  The worker count is 0 upon object initialization.
+  void AddWorkers(int num_new_workers) {
+    // No need to lock num_workers_mutex_ because this is before Initialize().
+    num_workers_ += num_new_workers;
+  }
+
+  // Called by the control thread.  May not be called multiple times.  If
+  // called, Destroy() must be called before destruction.
+  void Initialize();
+
+  // Called by the control thread after joining all worker threads.  Must be
+  // called iff Initialize() was called.  No methods may be called after calling
+  // this.
+  void Destroy();
+
+  // Called by the control thread to tell the workers to pause.  Does not return
+  // until all workers have called ContinueRunning() or RemoveSelf().  May only
+  // be called between Initialize() and Stop().  Must not be called multiple
+  // times without ResumeWorkers() having been called inbetween.
+  void PauseWorkers();
+
+  // Called by the control thread to tell the workers to resume from a pause.
+  // May only be called between Initialize() and Stop().  May only be called
+  // directly after PauseWorkers().
+  void ResumeWorkers();
+
+  // Called by the control thread to tell the workers to stop.  May only be
+  // called between Initialize() and Destroy().  May only be called once.
+  void StopWorkers();
+
+  //--------------------------------
+  // Methods for the worker threads.
+  //--------------------------------
+
+  // Called by worker threads to decrease the worker count by one.  May only be
+  // called between Initialize() and Destroy().  May wait for ResumeWorkers()
+  // when called after PauseWorkers().
+  void RemoveSelf();
+
+  // Called by worker threads between Initialize() and Destroy().  May be called
+  // any number of times.  Return value is whether or not the worker should
+  // continue running.  When called after PauseWorkers(), does not return until
+  // ResumeWorkers() or StopWorkers() has been called.  Number of distinct
+  // calling threads must match the worker count (see AddWorkers() and
+  // RemoveSelf()).
+  bool ContinueRunning();
+
+  // TODO(matthewb): Is this functionality really necessary?  Remove it if not.
+  //
+  // This is a hack!  It's like ContinueRunning(), except it won't pause.  If
+  // any worker threads use this exclusively in place of ContinueRunning() then
+  // PauseWorkers() should never be used!
+  bool ContinueRunningNoPause();
+
+ private:
+  enum Status { RUN, PAUSE, STOP };
+
+  void WaitOnPauseBarrier() {
+    int error = pthread_barrier_wait(&pause_barrier_);
+    if (error != PTHREAD_BARRIER_SERIAL_THREAD)
+      sat_assert(error == 0);
+  }
+
+  void AcquireNumWorkersLock() {
+    sat_assert(0 == pthread_mutex_lock(&num_workers_mutex_));
+  }
+
+  void ReleaseNumWorkersLock() {
+    sat_assert(0 == pthread_mutex_unlock(&num_workers_mutex_));
+  }
+
+  void AcquireStatusReadLock() {
+    sat_assert(0 == pthread_rwlock_rdlock(&status_rwlock_));
+  }
+
+  void AcquireStatusWriteLock() {
+    sat_assert(0 == pthread_rwlock_wrlock(&status_rwlock_));
+  }
+
+  void ReleaseStatusLock() {
+    sat_assert(0 == pthread_rwlock_unlock(&status_rwlock_));
+  }
+
+  Status GetStatus() {
+    AcquireStatusReadLock();
+    Status status = status_;
+    ReleaseStatusLock();
+    return status;
+  }
+
+  // Returns the previous status.
+  Status SetStatus(Status status) {
+    AcquireStatusWriteLock();
+    Status prev_status = status_;
+    status_ = status;
+    ReleaseStatusLock();
+    return prev_status;
+  }
+
+  pthread_mutex_t num_workers_mutex_;
+  int num_workers_;
+
+  pthread_rwlock_t status_rwlock_;
+  Status status_;
+
+  // Guaranteed to not be in use when (status_ != PAUSE).
+  pthread_barrier_t pause_barrier_;
+
+  DISALLOW_COPY_AND_ASSIGN(WorkerStatus);
+};
+
+
+// This is a base class for worker threads.
+// Each thread repeats a specific
+// task on various blocks of memory.
+class WorkerThread {
+ public:
+  // Enum to mark a thread as low/med/high priority.
+  enum Priority {
+    Low,
+    Normal,
+    High,
+  };
+  WorkerThread();
+  virtual ~WorkerThread();
+
+  // Initialize values and thread ID number.
+  virtual void InitThread(int thread_num_init,
+                          class Sat *sat_init,
+                          class OsLayer *os_init,
+                          class PatternList *patternlist_init,
+                          WorkerStatus *worker_status);
+
+  // This function is DEPRECATED, it does nothing.
+  void SetPriority(Priority priority) { priority_ = priority; }
+  // Spawn the worker thread, by running Work().
+  int SpawnThread();
+  // Only for ThreadSpawnerGeneric().
+  void StartRoutine();
+  bool InitPriority();
+
+  // Wait for the thread to complete its cleanup.
+  virtual bool JoinThread();
+  // Kill worker thread with SIGINT.
+  virtual bool KillThread();
+
+  // This is the task function that the thread executes.
+  // This is implemented per subclass.
+  virtual bool Work();
+
+  // Starts per-WorkerThread timer.
+  void StartThreadTimer() {gettimeofday(&start_time_, NULL);}
+  // Reads current timer value and returns run duration without recording it.
+  int64 ReadThreadTimer() {
+    struct timeval end_time_;
+    gettimeofday(&end_time_, NULL);
+    return (end_time_.tv_sec - start_time_.tv_sec)*1000000 +
+      (end_time_.tv_usec - start_time_.tv_usec);
+  }
+  // Stops per-WorkerThread timer and records thread run duration.
+  // Start/Stop ThreadTimer repetitively has cumulative effect, ie the timer
+  // is effectively paused and restarted, so runduration_usec accumulates on.
+  void StopThreadTimer() {
+    runduration_usec_ += ReadThreadTimer();
+  }
+
+  // Acccess member variables.
+  bool GetStatus() {return status_;}
+  int64 GetErrorCount() {return errorcount_;}
+  int64 GetPageCount() {return pages_copied_;}
+  int64 GetRunDurationUSec() {return runduration_usec_;}
+
+  // Returns bandwidth defined as pages_copied / thread_run_durations.
+  virtual float GetCopiedData();
+  // Calculate worker thread specific copied data.
+  virtual float GetMemoryCopiedData() {return 0;}
+  virtual float GetDeviceCopiedData() {return 0;}
+  // Calculate worker thread specific bandwidth.
+  virtual float GetMemoryBandwidth()
+    {return GetMemoryCopiedData() / (
+        runduration_usec_ * 1.0 / 1000000);}
+  virtual float GetDeviceBandwidth()
+    {return GetDeviceCopiedData() / (
+        runduration_usec_ * 1.0 / 1000000);}
+
+  void set_cpu_mask(cpu_set_t *mask) {
+    memcpy(&cpu_mask_, mask, sizeof(*mask));
+  }
+
+  void set_cpu_mask_to_cpu(int cpu_num) {
+    cpuset_set_ab(&cpu_mask_, cpu_num, cpu_num + 1);
+  }
+
+  void set_tag(int32 tag) {tag_ = tag;}
+
+  // Returns CPU mask, where each bit represents a logical cpu.
+  bool AvailableCpus(cpu_set_t *cpuset);
+  // Returns CPU mask of CPUs this thread is bound to,
+  bool CurrentCpus(cpu_set_t *cpuset);
+  // Returns Current Cpus mask as string.
+  string CurrentCpusFormat() {
+    cpu_set_t current_cpus;
+    CurrentCpus(&current_cpus);
+    return cpuset_format(&current_cpus);
+  }
+
+  int ThreadID() {return thread_num_;}
+
+  // Bind worker thread to specified CPU(s)
+  bool BindToCpus(const cpu_set_t *cpuset);
+
+ protected:
+  // This function dictates whether the main work loop
+  // continues, waits, or terminates.
+  // All work loops should be of the form:
+  //   do {
+  //     // work.
+  //   } while (IsReadyToRun());
+  virtual bool IsReadyToRun() { return worker_status_->ContinueRunning(); }
+  // TODO(matthewb): Is this function really necessary? Remove it if not.
+  //
+  // Like IsReadyToRun(), except it won't pause.
+  virtual bool IsReadyToRunNoPause() {
+    return worker_status_->ContinueRunningNoPause();
+  }
+
+  // These are functions used by the various work loops.
+  // Pretty print and log a data miscompare.
+  virtual void ProcessError(struct ErrorRecord *er,
+                            int priority,
+                            const char *message);
+
+  // Compare a region of memory with a known data patter, and report errors.
+  virtual int CheckRegion(void *addr,
+                          class Pattern *pat,
+                          int64 length,
+                          int offset,
+                          int64 patternoffset);
+
+  // Fast compare a block of memory.
+  virtual int CrcCheckPage(struct page_entry *srcpe);
+
+  // Fast copy a block of memory, while verifying correctness.
+  virtual int CrcCopyPage(struct page_entry *dstpe,
+                          struct page_entry *srcpe);
+
+  // Fast copy a block of memory, while verifying correctness, and heating CPU.
+  virtual int CrcWarmCopyPage(struct page_entry *dstpe,
+                              struct page_entry *srcpe);
+
+  // Fill a page with its specified pattern.
+  virtual bool FillPage(struct page_entry *pe);
+
+  // Copy with address tagging.
+  virtual bool AdlerAddrMemcpyC(uint64 *dstmem64,
+                                uint64 *srcmem64,
+                                unsigned int size_in_bytes,
+                                AdlerChecksum *checksum,
+                                struct page_entry *pe);
+  // SSE copy with address tagging.
+  virtual bool AdlerAddrMemcpyWarm(uint64 *dstmem64,
+                                   uint64 *srcmem64,
+                                   unsigned int size_in_bytes,
+                                   AdlerChecksum *checksum,
+                                   struct page_entry *pe);
+  // Crc data with address tagging.
+  virtual bool AdlerAddrCrcC(uint64 *srcmem64,
+                             unsigned int size_in_bytes,
+                             AdlerChecksum *checksum,
+                             struct page_entry *pe);
+  // Setup tagging on an existing page.
+  virtual bool TagAddrC(uint64 *memwords,
+                        unsigned int size_in_bytes);
+  // Report a mistagged cacheline.
+  virtual bool ReportTagError(uint64 *mem64,
+                      uint64 actual,
+                      uint64 tag);
+  // Print out the error record of the tag mismatch.
+  virtual void ProcessTagError(struct ErrorRecord *error,
+                       int priority,
+                       const char *message);
+
+  // A worker thread can yield itself to give up CPU until it's scheduled again
+  bool YieldSelf();
+
+ protected:
+  // General state variables that all subclasses need.
+  int thread_num_;                  // Thread ID.
+  volatile bool status_;            // Error status.
+  volatile int64 pages_copied_;     // Recorded for memory bandwidth calc.
+  volatile int64 errorcount_;       // Miscompares seen by this thread.
+
+  cpu_set_t cpu_mask_;              // Cores this thread is allowed to run on.
+  volatile uint32 tag_;             // Tag hint for memory this thread can use.
+
+  bool tag_mode_;                   // Tag cachelines with vaddr.
+
+  // Thread timing variables.
+  struct timeval start_time_;        // Worker thread start time.
+  volatile int64 runduration_usec_;  // Worker run duration in u-seconds.
+
+  // Function passed to pthread_create.
+  void *(*thread_spawner_)(void *args);
+  pthread_t thread_;                // Pthread thread ID.
+  Priority priority_;               // Worker thread priority.
+  class Sat *sat_;                  // Reference to parent stest object.
+  class OsLayer *os_;               // Os abstraction: put hacks here.
+  class PatternList *patternlist_;  // Reference to data patterns.
+
+  // Work around style guide ban on sizeof(int).
+  static const uint64 iamint_ = 0;
+  static const int wordsize_ = sizeof(iamint_);
+
+ private:
+  WorkerStatus *worker_status_;
+
+  DISALLOW_COPY_AND_ASSIGN(WorkerThread);
+};
+
+// Worker thread to perform File IO.
+class FileThread : public WorkerThread {
+ public:
+  FileThread();
+  // Set filename to use for file IO.
+  virtual void SetFile(const char *filename_init);
+  virtual bool Work();
+
+  // Calculate worker thread specific bandwidth.
+  virtual float GetDeviceCopiedData()
+    {return GetCopiedData()*2;}
+  virtual float GetMemoryCopiedData();
+
+ protected:
+  // Record of where these pages were sourced from, and what
+  // potentially broken components they passed through.
+  struct PageRec {
+     struct Pattern *pattern;  // This is the data it should contain.
+     void *src;  // This is the memory location the data was sourced from.
+     void *dst;  // This is where it ended up.
+  };
+
+  // These are functions used by the various work loops.
+  // Pretty print and log a data miscompare. Disks require
+  // slightly different error handling.
+  virtual void ProcessError(struct ErrorRecord *er,
+                            int priority,
+                            const char *message);
+
+  virtual bool OpenFile(int *pfile);
+  virtual bool CloseFile(int fd);
+
+  // Read and write whole file to disk.
+  virtual bool WritePages(int fd);
+  virtual bool ReadPages(int fd);
+
+  // Read and write pages to disk.
+  virtual bool WritePageToFile(int fd, struct page_entry *src);
+  virtual bool ReadPageFromFile(int fd, struct page_entry *dst);
+
+  // Sector tagging support.
+  virtual bool SectorTagPage(struct page_entry *src, int block);
+  virtual bool SectorValidatePage(const struct PageRec &page,
+                                  struct page_entry *dst,
+                                  int block);
+
+  // Get memory for an incoming data transfer..
+  virtual bool PagePrepare();
+  // Remove memory allocated for data transfer.
+  virtual bool PageTeardown();
+
+  // Get memory for an incoming data transfer..
+  virtual bool GetEmptyPage(struct page_entry *dst);
+  // Get memory for an outgoing data transfer..
+  virtual bool GetValidPage(struct page_entry *dst);
+  // Throw out a used empty page.
+  virtual bool PutEmptyPage(struct page_entry *src);
+  // Throw out a used, filled page.
+  virtual bool PutValidPage(struct page_entry *src);
+
+
+  struct PageRec *page_recs_;          // Array of page records.
+  int crc_page_;                        // Page currently being CRC checked.
+  string filename_;                     // Name of file to access.
+  string devicename_;                   // Name of device file is on.
+
+  bool page_io_;                        // Use page pool for IO.
+  void *local_page_;                   // malloc'd page fon non-pool IO.
+  int pass_;                            // Number of writes to the file so far.
+
+  // Tag to detect file corruption.
+  struct SectorTag {
+    volatile uint8 magic;
+    volatile uint8 block;
+    volatile uint8 sector;
+    volatile uint8 pass;
+    char pad[512-4];
+  };
+
+  DISALLOW_COPY_AND_ASSIGN(FileThread);
+};
+
+
+// Worker thread to perform Network IO.
+class NetworkThread : public WorkerThread {
+ public:
+  NetworkThread();
+  // Set hostname to use for net IO.
+  virtual void SetIP(const char *ipaddr_init);
+  virtual bool Work();
+
+  // Calculate worker thread specific bandwidth.
+  virtual float GetDeviceCopiedData()
+    {return GetCopiedData()*2;}
+
+ protected:
+  // IsReadyToRunNoPause() wrapper, for NetworkSlaveThread to override.
+  virtual bool IsNetworkStopSet();
+  virtual bool CreateSocket(int *psocket);
+  virtual bool CloseSocket(int sock);
+  virtual bool Connect(int sock);
+  virtual bool SendPage(int sock, struct page_entry *src);
+  virtual bool ReceivePage(int sock, struct page_entry *dst);
+  char ipaddr_[256];
+  int sock_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NetworkThread);
+};
+
+// Worker thread to reflect Network IO.
+class NetworkSlaveThread : public NetworkThread {
+ public:
+  NetworkSlaveThread();
+  // Set socket for IO.
+  virtual void SetSock(int sock);
+  virtual bool Work();
+
+ protected:
+  virtual bool IsNetworkStopSet();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NetworkSlaveThread);
+};
+
+// Worker thread to detect incoming Network IO.
+class NetworkListenThread : public NetworkThread {
+ public:
+  NetworkListenThread();
+  virtual bool Work();
+
+ private:
+  virtual bool Listen();
+  virtual bool Wait();
+  virtual bool GetConnection(int *pnewsock);
+  virtual bool SpawnSlave(int newsock, int threadid);
+  virtual bool ReapSlaves();
+
+  // For serviced incoming connections.
+  struct ChildWorker {
+    WorkerStatus status;
+    NetworkSlaveThread thread;
+  };
+  typedef vector<ChildWorker*> ChildVector;
+  ChildVector child_workers_;
+
+  DISALLOW_COPY_AND_ASSIGN(NetworkListenThread);
+};
+
+// Worker thread to perform Memory Copy.
+class CopyThread : public WorkerThread {
+ public:
+  CopyThread() {}
+  virtual bool Work();
+  // Calculate worker thread specific bandwidth.
+  virtual float GetMemoryCopiedData()
+    {return GetCopiedData()*2;}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CopyThread);
+};
+
+// Worker thread to perform Memory Invert.
+class InvertThread : public WorkerThread {
+ public:
+  InvertThread() {}
+  virtual bool Work();
+  // Calculate worker thread specific bandwidth.
+  virtual float GetMemoryCopiedData()
+    {return GetCopiedData()*4;}
+
+ private:
+  virtual int InvertPageUp(struct page_entry *srcpe);
+  virtual int InvertPageDown(struct page_entry *srcpe);
+  DISALLOW_COPY_AND_ASSIGN(InvertThread);
+};
+
+// Worker thread to fill blank pages on startup.
+class FillThread : public WorkerThread {
+ public:
+  FillThread();
+  // Set how many pages this thread should fill before exiting.
+  virtual void SetFillPages(int64 num_pages_to_fill_init);
+  virtual bool Work();
+
+ private:
+  // Fill a page with the data pattern in pe->pattern.
+  virtual bool FillPageRandom(struct page_entry *pe);
+  int64 num_pages_to_fill_;
+  DISALLOW_COPY_AND_ASSIGN(FillThread);
+};
+
+// Worker thread to verify page data matches pattern data.
+// Thread will check and replace pages until "done" flag is set,
+// then it will check and discard pages until no more remain.
+class CheckThread : public WorkerThread {
+ public:
+  CheckThread() {}
+  virtual bool Work();
+  // Calculate worker thread specific bandwidth.
+  virtual float GetMemoryCopiedData()
+    {return GetCopiedData();}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CheckThread);
+};
+
+
+// Worker thread to poll for system error messages.
+// Thread will check for messages until "done" flag is set.
+class ErrorPollThread : public WorkerThread {
+ public:
+  ErrorPollThread() {}
+  virtual bool Work();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ErrorPollThread);
+};
+
+// Computation intensive worker thread to stress CPU.
+class CpuStressThread : public WorkerThread {
+ public:
+  CpuStressThread() {}
+  virtual bool Work();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CpuStressThread);
+};
+
+// Worker thread that tests the correctness of the
+// CPU Cache Coherency Protocol.
+class CpuCacheCoherencyThread : public WorkerThread {
+ public:
+  CpuCacheCoherencyThread(cc_cacheline_data *cc_data,
+                          int cc_cacheline_count_,
+                          int cc_thread_num_,
+                          int cc_inc_count_);
+  virtual bool Work();
+
+ protected:
+  cc_cacheline_data *cc_cacheline_data_;  // Datstructure for each cacheline.
+  int cc_local_num_;        // Local counter for each thread.
+  int cc_cacheline_count_;  // Number of cache lines to operate on.
+  int cc_thread_num_;       // The integer id of the thread which is
+                            // used as an index into the integer array
+                            // of the cacheline datastructure.
+  int cc_inc_count_;        // Number of times to increment the counter.
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CpuCacheCoherencyThread);
+};
+
+// Worker thread to perform disk test.
+class DiskThread : public WorkerThread {
+ public:
+  explicit DiskThread(DiskBlockTable *block_table);
+  virtual ~DiskThread();
+  // Calculate disk thread specific bandwidth.
+  virtual float GetDeviceCopiedData() {
+    return (blocks_written_ * write_block_size_ +
+            blocks_read_ * read_block_size_) / kMegabyte;}
+
+  // Set filename for device file (in /dev).
+  virtual void SetDevice(const char *device_name);
+  // Set various parameters that control the behaviour of the test.
+  virtual bool SetParameters(int read_block_size,
+                             int write_block_size,
+                             int64 segment_size,
+                             int64 cache_size,
+                             int blocks_per_segment,
+                             int64 read_threshold,
+                             int64 write_threshold,
+                             int non_destructive);
+
+  virtual bool Work();
+
+  virtual float GetMemoryCopiedData() {return 0;}
+
+ protected:
+  static const int kSectorSize = 512;       // Size of sector on disk.
+  static const int kBufferAlignment = 512;  // Buffer alignment required by the
+                                            // kernel.
+  static const int kBlockRetry = 100;       // Number of retries to allocate
+                                            // sectors.
+
+  enum IoOp {
+    ASYNC_IO_READ   = 0,
+    ASYNC_IO_WRITE  = 1
+  };
+
+  virtual bool OpenDevice(int *pfile);
+  virtual bool CloseDevice(int fd);
+
+  // Retrieves the size (in bytes) of the disk/file.
+  virtual bool GetDiskSize(int fd);
+
+  // Retrieves the current time in microseconds.
+  virtual int64 GetTime();
+
+  // Do an asynchronous disk I/O operation.
+  virtual bool AsyncDiskIO(IoOp op, int fd, void *buf, int64 size,
+                           int64 offset, int64 timeout);
+
+  // Write a block to disk.
+  virtual bool WriteBlockToDisk(int fd, BlockData *block);
+
+  // Verify a block on disk.
+  virtual bool ValidateBlockOnDisk(int fd, BlockData *block);
+
+  // Main work loop.
+  virtual bool DoWork(int fd);
+
+  int read_block_size_;       // Size of blocks read from disk, in bytes.
+  int write_block_size_;      // Size of blocks written to disk, in bytes.
+  int64 blocks_read_;         // Number of blocks read in work loop.
+  int64 blocks_written_;      // Number of blocks written in work loop.
+  int64 segment_size_;        // Size of disk segments (in bytes) that the disk
+                              // will be split into where testing can be
+                              // confined to a particular segment.
+                              // Allows for control of how evenly the disk will
+                              // be tested.  Smaller segments imply more even
+                              // testing (less random).
+  int blocks_per_segment_;    // Number of blocks that will be tested per
+                              // segment.
+  int cache_size_;            // Size of disk cache, in bytes.
+  int queue_size_;            // Length of in-flight-blocks queue, in blocks.
+  int non_destructive_;       // Use non-destructive mode or not.
+  int update_block_table_;    // If true, assume this is the thread
+                              // responsible for writing the data in the disk
+                              // for this block device and, therefore,
+                              // update the block table. If false, just use
+                              // the block table to get data.
+
+  // read/write times threshold for reporting a problem
+  int64 read_threshold_;      // Maximum time a read should take (in us) before
+                              // a warning is given.
+  int64 write_threshold_;     // Maximum time a write should take (in us) before
+                              // a warning is given.
+  int64 read_timeout_;        // Maximum time a read can take before a timeout
+                              // and the aborting of the read operation.
+  int64 write_timeout_;       // Maximum time a write can take before a timeout
+                              // and the aborting of the write operation.
+
+  string device_name_;        // Name of device file to access.
+  int64 device_sectors_;      // Number of sectors on the device.
+
+  std::queue<BlockData*> in_flight_sectors_;   // Queue of sectors written but
+                                                // not verified.
+  void *block_buffer_;        // Pointer to aligned block buffer.
+
+  io_context_t aio_ctx_;     // Asynchronous I/O context for Linux native AIO.
+
+  DiskBlockTable *block_table_;  // Disk Block Table, shared by all disk
+                                 // threads that read / write at the same
+                                 // device
+
+  DISALLOW_COPY_AND_ASSIGN(DiskThread);
+};
+
+class RandomDiskThread : public DiskThread {
+ public:
+  explicit RandomDiskThread(DiskBlockTable *block_table);
+  virtual ~RandomDiskThread();
+  // Main work loop.
+  virtual bool DoWork(int fd);
+ protected:
+  DISALLOW_COPY_AND_ASSIGN(RandomDiskThread);
+};
+
+// Worker thread to perform checks in a specific memory region.
+class MemoryRegionThread : public WorkerThread {
+ public:
+  MemoryRegionThread();
+  ~MemoryRegionThread();
+  virtual bool Work();
+  void ProcessError(struct ErrorRecord *error, int priority,
+                    const char *message);
+  bool SetRegion(void *region, int64 size);
+  // Calculate worker thread specific bandwidth.
+  virtual float GetMemoryCopiedData()
+    {return GetCopiedData();}
+  virtual float GetDeviceCopiedData()
+    {return GetCopiedData() * 2;}
+  void SetIdentifier(string identifier) {
+    identifier_ = identifier;
+  }
+
+ protected:
+  // Page queue for this particular memory region.
+  char *region_;
+  PageEntryQueue *pages_;
+  bool error_injection_;
+  int phase_;
+  string identifier_;
+  static const int kPhaseNoPhase = 0;
+  static const int kPhaseCopy = 1;
+  static const int kPhaseCheck = 2;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MemoryRegionThread);
+};
+
+#endif  // STRESSAPPTEST_WORKER_H_