gecko-dev/memory/build/mozmemory.h

92 строки
3.1 KiB
C

/* 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 */