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#define JEMALLOC_PAGES_C_
#include "jemalloc/internal/jemalloc_internal.h"
/******************************************************************************/
/* Defines/includes needed for special android code. */
#if defined(__ANDROID__)
#include <sys/prctl.h>
/* Definitions of prctl arguments to set a vma name in Android kernels. */
#define ANDROID_PR_SET_VMA 0x53564d41
#define ANDROID_PR_SET_VMA_ANON_NAME 0
#endif
/******************************************************************************/
void *
pages_map(void *addr, size_t size)
{
void *ret;
assert(size != 0);
#ifdef _WIN32
/*
* If VirtualAlloc can't allocate at the given address when one is
* given, it fails and returns NULL.
*/
ret = VirtualAlloc(addr, size, MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE);
#else
/*
* We don't use MAP_FIXED here, because it can cause the *replacement*
* of existing mappings, and we only want to create new mappings.
*/
ret = mmap(addr, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON,
-1, 0);
assert(ret != NULL);
if (ret == MAP_FAILED)
ret = NULL;
else if (addr != NULL && ret != addr) {
/*
* We succeeded in mapping memory, but not in the right place.
*/
pages_unmap(ret, size);
ret = NULL;
}
#endif
#if defined(__ANDROID__)
if (ret != NULL) {
/* Name this memory as being used by libc */
prctl(ANDROID_PR_SET_VMA, ANDROID_PR_SET_VMA_ANON_NAME, ret,
size, "libc_malloc");
}
#endif
assert(ret == NULL || (addr == NULL && ret != addr)
|| (addr != NULL && ret == addr));
return (ret);
}
void
pages_unmap(void *addr, size_t size)
{
#ifdef _WIN32
if (VirtualFree(addr, 0, MEM_RELEASE) == 0)
#else
if (munmap(addr, size) == -1)
#endif
{
char buf[BUFERROR_BUF];
buferror(get_errno(), buf, sizeof(buf));
malloc_printf("<jemalloc>: Error in "
#ifdef _WIN32
"VirtualFree"
#else
"munmap"
#endif
"(): %s\n", buf);
if (opt_abort)
abort();
}
}
void *
pages_trim(void *addr, size_t alloc_size, size_t leadsize, size_t size)
{
void *ret = (void *)((uintptr_t)addr + leadsize);
assert(alloc_size >= leadsize + size);
#ifdef _WIN32
{
void *new_addr;
pages_unmap(addr, alloc_size);
new_addr = pages_map(ret, size);
if (new_addr == ret)
return (ret);
if (new_addr)
pages_unmap(new_addr, size);
return (NULL);
}
#else
{
size_t trailsize = alloc_size - leadsize - size;
if (leadsize != 0)
pages_unmap(addr, leadsize);
if (trailsize != 0)
pages_unmap((void *)((uintptr_t)ret + size), trailsize);
return (ret);
}
#endif
}
static bool
pages_commit_impl(void *addr, size_t size, bool commit)
{
#ifndef _WIN32
/*
* The following decommit/commit implementation is functional, but
* always disabled because it doesn't add value beyong improved
* debugging (at the cost of extra system calls) on systems that
* overcommit.
*/
if (false) {
int prot = commit ? (PROT_READ | PROT_WRITE) : PROT_NONE;
void *result = mmap(addr, size, prot, MAP_PRIVATE | MAP_ANON |
MAP_FIXED, -1, 0);
if (result == MAP_FAILED)
return (true);
if (result != addr) {
/*
* We succeeded in mapping memory, but not in the right
* place.
*/
pages_unmap(result, size);
return (true);
}
return (false);
}
#endif
return (true);
}
bool
pages_commit(void *addr, size_t size)
{
return (pages_commit_impl(addr, size, true));
}
bool
pages_decommit(void *addr, size_t size)
{
return (pages_commit_impl(addr, size, false));
}
bool
pages_purge(void *addr, size_t size)
{
bool unzeroed;
#ifdef _WIN32
VirtualAlloc(addr, size, MEM_RESET, PAGE_READWRITE);
unzeroed = true;
#elif defined(JEMALLOC_HAVE_MADVISE)
# ifdef JEMALLOC_PURGE_MADVISE_DONTNEED
# define JEMALLOC_MADV_PURGE MADV_DONTNEED
# define JEMALLOC_MADV_ZEROS true
# elif defined(JEMALLOC_PURGE_MADVISE_FREE)
# define JEMALLOC_MADV_PURGE MADV_FREE
# define JEMALLOC_MADV_ZEROS false
# else
# error "No madvise(2) flag defined for purging unused dirty pages."
# endif
int err = madvise(addr, size, JEMALLOC_MADV_PURGE);
unzeroed = (!JEMALLOC_MADV_ZEROS || err != 0);
# undef JEMALLOC_MADV_PURGE
# undef JEMALLOC_MADV_ZEROS
#else
/* Last resort no-op. */
unzeroed = true;
#endif
return (unzeroed);
}
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