gecko-dev/memory/build/mozmemory_wrap.h

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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_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_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. Additionally,
* C++ allocation functions (operator new/delete) are also exported and
* unprefixed.
*
* - On other systems (mostly Linux), all functions are left unprefixed.
*
* Only Android adds C++ allocation functions.
*
* 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
# if defined(MOZ_WIDGET_ANDROID)
# define MOZ_WRAP_NEW_DELETE
# endif
# 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)
#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 */