gecko-dev/memory/mozjemalloc/jemalloc.h
2012-06-07 10:41:59 +02:00

117 lines
3.9 KiB
C

/* -*- Mode: C; tab-width: 8; c-basic-offset: 8 -*- */
/* vim:set softtabstop=8 shiftwidth=8: */
/*-
* Copyright (C) 2006-2008 Jason Evans <jasone@FreeBSD.org>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice(s), this list of conditions and the following disclaimer as
* the first lines of this file unmodified other than the possible
* addition of one or more copyright notices.
* 2. Redistributions in binary form must reproduce the above copyright
* notice(s), this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _JEMALLOC_H_
#define _JEMALLOC_H_
#if defined(MOZ_MEMORY_DARWIN)
#include <malloc/malloc.h>
#endif
#include "jemalloc_types.h"
#ifdef __cplusplus
extern "C" {
#endif
#if defined(MOZ_MEMORY_LINUX)
__attribute__((weak))
#endif
void jemalloc_stats(jemalloc_stats_t *stats);
/* Computes the usable size in advance. */
#if !defined(MOZ_MEMORY_DARWIN)
#if defined(MOZ_MEMORY_LINUX)
__attribute__((weak))
#endif
#if defined(MOZ_JEMALLOC)
int je_nallocm(size_t *rsize, size_t size, int flags);
#else
size_t je_malloc_good_size(size_t size);
#endif
#endif
static inline size_t je_malloc_usable_size_in_advance(size_t size) {
#if defined(MOZ_MEMORY_DARWIN)
return malloc_good_size(size);
#elif defined(MOZ_JEMALLOC)
if (je_nallocm) {
size_t ret;
if (size == 0)
size = 1;
if (!je_nallocm(&ret, size, 0))
return ret;
}
return size;
#else
if (je_malloc_good_size)
return je_malloc_good_size(size);
else
return size;
#endif
}
/*
* 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.
*/
#if defined(MOZ_MEMORY_LINUX) || defined(MOZ_JEMALLOC)
static inline void jemalloc_purge_freed_pages() { }
#else
void jemalloc_purge_freed_pages();
#endif
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* _JEMALLOC_H_ */