6797870: Add -XX:+{HeapDump,PrintClassHistogram}{Before,After}FullGC

Summary: Call newly created CollectedHeap::dump_{pre,post}_full_gc before and after every stop-world full collection cycle on GenCollectedHeap and ParallelScavengeHeap. (Support for G1CollectedHeap forthcoming under CR 6810861.) Small modifications to existing heap dumping and class histogram implementation, especially to allow multiple on-the-fly histos/dumps by the VM thread during a single safepoint.
Reviewed-by: jmasa, alanb, mchung

4 files changed, 13 insertions, 2 deletions

diff --git a/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp b/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp
index 608eedb8f..059a3043f 100644
--- a/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp
+++ b/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp
@@ -125,6 +125,8 @@ void PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
     perm_gen->verify_object_start_array();
   }
 
+  heap->pre_full_gc_dump();
+
   // Filled in below to track the state of the young gen after the collection.
   bool eden_empty;
   bool survivors_empty;
@@ -363,6 +365,8 @@ void PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
     Universe::print_heap_after_gc();
   }
 
+  heap->post_full_gc_dump();
+
 #ifdef TRACESPINNING
   ParallelTaskTerminator::print_termination_counts();
 #endif
diff --git a/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp b/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp
index 686c65b2c..4a4293c79 100644
--- a/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp
+++ b/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp
@@ -1982,6 +1982,8 @@ void PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
     heap->record_gen_tops_before_GC();
   }
 
+  heap->pre_full_gc_dump();
+
   _print_phases = PrintGCDetails && PrintParallelOldGCPhaseTimes;
 
   // Make sure data structures are sane, make the heap parsable, and do other
@@ -2204,6 +2206,8 @@ void PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
     gc_task_manager()->print_task_time_stamps();
   }
 
+  heap->post_full_gc_dump();
+
 #ifdef TRACESPINNING
   ParallelTaskTerminator::print_termination_counts();
 #endif
diff --git a/src/share/vm/gc_implementation/shared/vmGCOperations.cpp b/src/share/vm/gc_implementation/shared/vmGCOperations.cpp
index 7b4b76696..c23027527 100644
--- a/src/share/vm/gc_implementation/shared/vmGCOperations.cpp
+++ b/src/share/vm/gc_implementation/shared/vmGCOperations.cpp
@@ -121,7 +121,7 @@ void VM_GC_HeapInspection::doit() {
     // make the heap parsable (no need to retire TLABs)
     ch->ensure_parsability(false);
   }
-  HeapInspection::heap_inspection(_out);
+  HeapInspection::heap_inspection(_out, _need_prologue /* need_prologue */);
 }
 
 
diff --git a/src/share/vm/gc_implementation/shared/vmGCOperations.hpp b/src/share/vm/gc_implementation/shared/vmGCOperations.hpp
index fcce0cc3b..6ff704fdf 100644
--- a/src/share/vm/gc_implementation/shared/vmGCOperations.hpp
+++ b/src/share/vm/gc_implementation/shared/vmGCOperations.hpp
@@ -112,13 +112,16 @@ class VM_GC_HeapInspection: public VM_GC_Operation {
  private:
   outputStream* _out;
   bool _full_gc;
+  bool _need_prologue;
  public:
-  VM_GC_HeapInspection(outputStream* out, bool request_full_gc) :
+  VM_GC_HeapInspection(outputStream* out, bool request_full_gc,
+                       bool need_prologue) :
     VM_GC_Operation(0 /* total collections,      dummy, ignored */,
                     0 /* total full collections, dummy, ignored */,
                     request_full_gc) {
     _out = out;
     _full_gc = request_full_gc;
+    _need_prologue = need_prologue;
   }
 
   ~VM_GC_HeapInspection() {}