memory/build/mozmemory.h
author Wes Kocher <wkocher@mozilla.com>
Thu, 19 Sep 2013 17:56:18 -0700
changeset 162779 1f6d484652904ce39c0145050c9c2a69dffe4d3a
parent 125191 af6ca1b6b58a4f61fe0e9436d56a52d007f71013
child 166381 e5e074ddca9e5fa433a8537898a4a8d093e05d9c
permissions -rw-r--r--
Backed out 5 changesets (bug 907926, bug 911393, bug 917703) due to OSX reftest bustage during an unrelated CLOSED TREE Backed out changeset 94a6733b01dc (bug 907926) Backed out changeset 44108fb6f7cc (bug 917703) Backed out changeset f2dd2a27af69 (bug 911393) Backed out changeset fdb0d1053128 (bug 907926) Backed out changeset b3616b786e8f (bug 907926)

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozmemory_h
#define mozmemory_h

/*
 * This header is meant to be used when the following functions are
 * necessary:
 *   - malloc_good_size (used to be called je_malloc_usable_in_advance)
 *   - jemalloc_stats
 *   - jemalloc_purge_freed_pages
 *   - jemalloc_free_dirty_pages
 */

#ifndef MOZ_MEMORY
#  error Should not include mozmemory.h when MOZ_MEMORY is not set
#endif

#include "mozmemory_wrap.h"
#include "mozilla/Attributes.h"
#include "mozilla/Types.h"
#include "jemalloc_types.h"

MOZ_BEGIN_EXTERN_C

/*
 * On OSX, malloc/malloc.h contains the declaration for malloc_good_size,
 * which will call back in jemalloc, through the zone allocator so just use it.
 */
#ifdef XP_DARWIN
#  include <malloc/malloc.h>
#else
MOZ_MEMORY_API size_t malloc_good_size_impl(size_t size);

/* Note: the MOZ_GLUE_IN_PROGRAM ifdef below is there to avoid -Werror turning
 * the protective if into errors. MOZ_GLUE_IN_PROGRAM is what triggers MFBT_API
 * to use weak imports. */

static MOZ_INLINE size_t _malloc_good_size(size_t size) {
#  if defined(MOZ_GLUE_IN_PROGRAM) && !defined(IMPL_MFBT)
  if (!malloc_good_size)
    return size;
#  endif
  return malloc_good_size_impl(size);
}

#  define malloc_good_size _malloc_good_size
#endif

MOZ_JEMALLOC_API void jemalloc_stats(jemalloc_stats_t *stats);

/*
 * On some operating systems (Mac), we use madvise(MADV_FREE) to hand pages
 * back to the operating system.  On Mac, the operating system doesn't take
 * this memory back immediately; instead, the OS takes it back only when the
 * machine is running out of physical memory.
 *
 * This is great from the standpoint of efficiency, but it makes measuring our
 * actual RSS difficult, because pages which we've MADV_FREE'd shouldn't count
 * against our RSS.
 *
 * This function explicitly purges any MADV_FREE'd pages from physical memory,
 * causing our reported RSS match the amount of memory we're actually using.
 *
 * Note that this call is expensive in two ways.  First, it may be slow to
 * execute, because it may make a number of slow syscalls to free memory.  This
 * function holds the big jemalloc locks, so basically all threads are blocked
 * while this function runs.
 *
 * This function is also expensive in that the next time we go to access a page
 * which we've just explicitly decommitted, the operating system has to attach
 * to it a physical page!  If we hadn't run this function, the OS would have
 * less work to do.
 *
 * If MALLOC_DOUBLE_PURGE is not defined, this function does nothing.
 */
MOZ_JEMALLOC_API void jemalloc_purge_freed_pages();

/*
 * Free all unused dirty pages in all arenas. Calling this function will slow
 * down subsequent allocations so it is recommended to use it only when
 * memory needs to be reclaimed at all costs (see bug 805855). This function
 * provides functionality similar to mallctl("arenas.purge") in jemalloc 3.
 */
MOZ_JEMALLOC_API void jemalloc_free_dirty_pages();

MOZ_END_EXTERN_C

#endif /* mozmemory_h */