mozmemory_wrap.h - mozsearch

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* 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_wrap_h

#define mozmemory_wrap_h

// This header contains #defines which tweak the names of various memory

// allocation functions.

//

// There are several types of functions related to memory allocation

// that are meant to be used publicly by the Gecko codebase:

//

// - malloc implementation functions:

//   - malloc

//   - posix_memalign

//   - aligned_alloc

//   - calloc

//   - realloc

//   - free

//   - memalign

//   - valloc

//   - malloc_usable_size

//   - malloc_good_size

//   Some of these functions are specific to some systems, but for

//   convenience, they are treated as being cross-platform, and available

//   as such.

//

// - duplication functions:

//   - strndup

//   - strdup

//   - wcsdup (Windows only)

//

// - jemalloc specific functions:

//   - jemalloc_stats

//   - jemalloc_stats_num_bins

//   - jemalloc_purge_freed_pages

//   - jemalloc_free_dirty_pages

//   - jemalloc_thread_local_arena

//   - jemalloc_ptr_info

//   (these functions are native to mozjemalloc)

//

// These functions are all exported as part of libmozglue (see

// $(topsrcdir)/mozglue/build/Makefile.in), with a few implementation

// peculiarities:

//

// - On Windows, the malloc implementation functions are all prefixed with

//   "je_", the duplication functions are prefixed with "wrap_", and jemalloc

//   specific functions are left unprefixed. All these functions are however

//   aliased when exporting them, such that the resulting mozglue.dll exports

//   them unprefixed (see $(topsrcdir)/mozglue/build/mozglue.def.in). The

//   prefixed malloc implementation and duplication functions are not

//   exported.

//

// - On MacOSX, the system libc has a zone allocator, which allows us to

//   hook custom malloc implementation functions without exporting them.

//   However, since we want things in Firefox to skip the system zone

//   allocator, the malloc implementation functions are all exported

//   unprefixed, as well as duplication functions.

//   Jemalloc-specific functions are also left unprefixed.

//

// - On Android all functions are left unprefixed.

//

// - On other systems (mostly Linux), all functions are left unprefixed.

//

// On all platforms, C++ allocation functions are also exported.

//

// Proper exporting of the various functions is done with the MOZ_MEMORY_API

// and MOZ_JEMALLOC_API macros. MOZ_MEMORY_API is meant to be used for malloc

// implementation and duplication functions, while MOZ_JEMALLOC_API is

// dedicated to jemalloc specific functions.

//

//

// All these functions are meant to be called with no prefix from Gecko code.

// In most cases, this is because that's how they are available at runtime.

// However, on Android, this relies on faulty.lib (the custom dynamic linker)

// resolving mozglue symbols before libc symbols, which is guaranteed by the

// way faulty.lib works (it respects the DT_NEEDED order, and libc always

// appears after mozglue ; which we double check when building anyways)

//

//

// Within libmozglue (when MOZ_MEMORY_IMPL is defined), all the functions

// should be suffixed with "_impl" both for declarations and use.

// That is, the implementation declaration for e.g. strdup would look like:

//   char* strdup_impl(const char *)

// That implementation would call malloc by using "malloc_impl".

#if defined(MOZ_MEMORY_IMPL) && !defined(IMPL_MFBT)

#  ifdef MFBT_API  // mozilla/Types.h was already included

#    error mozmemory_wrap.h has to be included before mozilla/Types.h when MOZ_MEMORY_IMPL is set and IMPL_MFBT is not.

#  endif

#  define IMPL_MFBT

#endif

#include "mozilla/Types.h"

#ifndef MOZ_EXTERN_C

#  ifdef __cplusplus

#    define MOZ_EXTERN_C extern "C"

#  else

#    define MOZ_EXTERN_C

#  endif

#endif

#ifdef MOZ_MEMORY_IMPL

#  define MOZ_JEMALLOC_API MOZ_EXTERN_C MFBT_API

#  if defined(XP_WIN)

#    define mozmem_malloc_impl(a) je_##a

#  else

#    define MOZ_MEMORY_API MOZ_EXTERN_C MFBT_API

#  endif

#endif

#ifdef XP_WIN

#  define mozmem_dup_impl(a) wrap_##a

#endif

#if !defined(MOZ_MEMORY_IMPL)

#  define MOZ_MEMORY_API MOZ_EXTERN_C MFBT_API

#  define MOZ_JEMALLOC_API MOZ_EXTERN_C MFBT_API

#endif

#ifndef MOZ_MEMORY_API

#  define MOZ_MEMORY_API MOZ_EXTERN_C

#endif

#ifndef MOZ_JEMALLOC_API

#  define MOZ_JEMALLOC_API MOZ_EXTERN_C

#endif

#ifndef mozmem_malloc_impl

#  define mozmem_malloc_impl(a) a

#endif

#ifndef mozmem_dup_impl

#  define mozmem_dup_impl(a) a

#endif

// Malloc implementation functions

#define malloc_impl mozmem_malloc_impl(malloc)

#define posix_memalign_impl mozmem_malloc_impl(posix_memalign)

#define aligned_alloc_impl mozmem_malloc_impl(aligned_alloc)

#define calloc_impl mozmem_malloc_impl(calloc)

#define realloc_impl mozmem_malloc_impl(realloc)

#define free_impl mozmem_malloc_impl(free)

#define memalign_impl mozmem_malloc_impl(memalign)

#define valloc_impl mozmem_malloc_impl(valloc)

#define malloc_usable_size_impl mozmem_malloc_impl(malloc_usable_size)

#define malloc_good_size_impl mozmem_malloc_impl(malloc_good_size)

// Duplication functions

#define strndup_impl mozmem_dup_impl(strndup)

#define strdup_impl mozmem_dup_impl(strdup)

#ifdef XP_WIN

#  define wcsdup_impl mozmem_dup_impl(wcsdup)

#  define _aligned_malloc_impl mozmem_dup_impl(_aligned_malloc)

#endif

// String functions

#ifdef ANDROID

// Bug 801571 and Bug 879668, libstagefright uses vasprintf, causing malloc()/

// free() to be mismatched between bionic and mozglue implementation.

#  define vasprintf_impl mozmem_dup_impl(vasprintf)

#  define asprintf_impl mozmem_dup_impl(asprintf)

#endif

#endif  // mozmemory_wrap_h