memory/build/mozmemory_wrap.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozmemory_wrap_h
   8 #define mozmemory_wrap_h
   9
  10 // This header contains #defines which tweak the names of various memory
  11 // allocation functions.
  12 //
  13 // There are several types of functions related to memory allocation
  14 // that are meant to be used publicly by the Gecko codebase:
  15 //
  16 // - malloc implementation functions:
  17 //   - malloc
  18 //   - posix_memalign
  19 //   - aligned_alloc
  20 //   - calloc
  21 //   - realloc
  22 //   - free
  23 //   - memalign
  24 //   - valloc
  25 //   - malloc_usable_size
  26 //   - malloc_good_size
  27 //   Some of these functions are specific to some systems, but for
  28 //   convenience, they are treated as being cross-platform, and available
  29 //   as such.
  30 //
  31 // - duplication functions:
  32 //   - strndup
  33 //   - strdup
  34 //   - wcsdup (Windows only)
  35 //
  36 // - jemalloc specific functions:
  37 //   - jemalloc_stats
  38 //   - jemalloc_stats_num_bins
  39 //   - jemalloc_purge_freed_pages
  40 //   - jemalloc_free_dirty_pages
  41 //   - jemalloc_thread_local_arena
  42 //   - jemalloc_ptr_info
  43 //   (these functions are native to mozjemalloc)
  44 //
  45 // These functions are all exported as part of libmozglue (see
  46 // $(topsrcdir)/mozglue/build/Makefile.in), with a few implementation
  47 // peculiarities:
  48 //
  49 // - On Windows, the malloc implementation functions are all prefixed with
  50 //   "je_", the duplication functions are prefixed with "wrap_", and jemalloc
  51 //   specific functions are left unprefixed. All these functions are however
  52 //   aliased when exporting them, such that the resulting mozglue.dll exports
  53 //   them unprefixed (see $(topsrcdir)/mozglue/build/mozglue.def.in). The
  54 //   prefixed malloc implementation and duplication functions are not
  55 //   exported.
  56 //
  57 // - On MacOSX, the system libc has a zone allocator, which allows us to
  58 //   hook custom malloc implementation functions without exporting them.
  59 //   However, since we want things in Firefox to skip the system zone
  60 //   allocator, the malloc implementation functions are all exported
  61 //   unprefixed, as well as duplication functions.
  62 //   Jemalloc-specific functions are also left unprefixed.
  63 //
  64 // - On Android all functions are left unprefixed.
  65 //
  66 // - On other systems (mostly Linux), all functions are left unprefixed.
  67 //
  68 // On all platforms, C++ allocation functions are also exported.
  69 //
  70 // Proper exporting of the various functions is done with the MOZ_MEMORY_API
  71 // and MOZ_JEMALLOC_API macros. MOZ_MEMORY_API is meant to be used for malloc
  72 // implementation and duplication functions, while MOZ_JEMALLOC_API is
  73 // dedicated to jemalloc specific functions.
  74 //
  75 //
  76 // All these functions are meant to be called with no prefix from Gecko code.
  77 // In most cases, this is because that's how they are available at runtime.
  78 // However, on Android, this relies on faulty.lib (the custom dynamic linker)
  79 // resolving mozglue symbols before libc symbols, which is guaranteed by the
  80 // way faulty.lib works (it respects the DT_NEEDED order, and libc always
  81 // appears after mozglue ; which we double check when building anyways)
  82 //
  83 //
  84 // Within libmozglue (when MOZ_MEMORY_IMPL is defined), all the functions
  85 // should be suffixed with "_impl" both for declarations and use.
  86 // That is, the implementation declaration for e.g. strdup would look like:
  87 //   char* strdup_impl(const char *)
  88 // That implementation would call malloc by using "malloc_impl".
  89
  90 #if defined(MOZ_MEMORY_IMPL) && !defined(IMPL_MFBT)
  91 #  ifdef MFBT_API  // mozilla/Types.h was already included
  92 #    error mozmemory_wrap.h has to be included before mozilla/Types.h when MOZ_MEMORY_IMPL is set and IMPL_MFBT is not.
  93 #  endif
  94 #  define IMPL_MFBT
  95 #endif
  96
  97 #include "mozilla/Types.h"
  98
  99 #ifndef MOZ_EXTERN_C
 100 #  ifdef __cplusplus
 101 #    define MOZ_EXTERN_C extern "C"
 102 #  else
 103 #    define MOZ_EXTERN_C
 104 #  endif
 105 #endif
 106
 107 #ifdef MOZ_MEMORY_IMPL
 108 #  define MOZ_JEMALLOC_API MOZ_EXTERN_C MFBT_API
 109 #  if defined(XP_WIN)
 110 #    define mozmem_malloc_impl(a) je_##a
 111 #  else
 112 #    define MOZ_MEMORY_API MOZ_EXTERN_C MFBT_API
 113 #  endif
 114 #endif
 115 #ifdef XP_WIN
 116 #  define mozmem_dup_impl(a) wrap_##a
 117 #endif
 118
 119 #if !defined(MOZ_MEMORY_IMPL)
 120 #  define MOZ_MEMORY_API MOZ_EXTERN_C MFBT_API
 121 #  define MOZ_JEMALLOC_API MOZ_EXTERN_C MFBT_API
 122 #endif
 123
 124 #ifndef MOZ_MEMORY_API
 125 #  define MOZ_MEMORY_API MOZ_EXTERN_C
 126 #endif
 127 #ifndef MOZ_JEMALLOC_API
 128 #  define MOZ_JEMALLOC_API MOZ_EXTERN_C
 129 #endif
 130
 131 #ifndef mozmem_malloc_impl
 132 #  define mozmem_malloc_impl(a) a
 133 #endif
 134 #ifndef mozmem_dup_impl
 135 #  define mozmem_dup_impl(a) a
 136 #endif
 137
 138 // Malloc implementation functions
 139 #define malloc_impl mozmem_malloc_impl(malloc)
 140 #define posix_memalign_impl mozmem_malloc_impl(posix_memalign)
 141 #define aligned_alloc_impl mozmem_malloc_impl(aligned_alloc)
 142 #define calloc_impl mozmem_malloc_impl(calloc)
 143 #define realloc_impl mozmem_malloc_impl(realloc)
 144 #define free_impl mozmem_malloc_impl(free)
 145 #define memalign_impl mozmem_malloc_impl(memalign)
 146 #define valloc_impl mozmem_malloc_impl(valloc)
 147 #define malloc_usable_size_impl mozmem_malloc_impl(malloc_usable_size)
 148 #define malloc_good_size_impl mozmem_malloc_impl(malloc_good_size)
 149
 150 // Duplication functions
 151 #define strndup_impl mozmem_dup_impl(strndup)
 152 #define strdup_impl mozmem_dup_impl(strdup)
 153 #ifdef XP_WIN
 154 #  define wcsdup_impl mozmem_dup_impl(wcsdup)
 155 #  define _aligned_malloc_impl mozmem_dup_impl(_aligned_malloc)
 156 #endif
 157
 158 // String functions
 159 #ifdef ANDROID
 160 // Bug 801571 and Bug 879668, libstagefright uses vasprintf, causing malloc()/
 161 // free() to be mismatched between bionic and mozglue implementation.
 162 #  define vasprintf_impl mozmem_dup_impl(vasprintf)
 163 #  define asprintf_impl mozmem_dup_impl(asprintf)
 164 #endif
 165
 166 #endif  // mozmemory_wrap_h