base/memory/aligned_memory.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/memory/aligned_memory.h"
   6
   7 #include "base/logging.h"
   8
   9 #if defined(OS_ANDROID)
  10 #include <malloc.h>
  11 #endif
  12
  13 namespace base {
  14
  15 void* AlignedAlloc(size_t size, size_t alignment) {
  16   DCHECK_GT(size, 0U);
  17   DCHECK_EQ(alignment & (alignment - 1), 0U);
  18   DCHECK_EQ(alignment % sizeof(void*), 0U);
  19   void* ptr = NULL;
  20 #if defined(COMPILER_MSVC)
  21   ptr = _aligned_malloc(size, alignment);
  22 // Android technically supports posix_memalign(), but does not expose it in
  23 // the current version of the library headers used by Chrome.  Luckily,
  24 // memalign() on Android returns pointers which can safely be used with
  25 // free(), so we can use it instead.  Issue filed to document this:
  26 // http://code.google.com/p/android/issues/detail?id=35391
  27 #elif defined(OS_ANDROID)
  28   ptr = memalign(alignment, size);
  29 #else
  30   if (posix_memalign(&ptr, alignment, size))
  31     ptr = NULL;
  32 #endif
  33   // Since aligned allocations may fail for non-memory related reasons, force a
  34   // crash if we encounter a failed allocation; maintaining consistent behavior
  35   // with a normal allocation failure in Chrome.
  36   if (!ptr) {
  37     DLOG(ERROR) << "If you crashed here, your aligned allocation is incorrect: "
  38                 << "size=" << size << ", alignment=" << alignment;
  39     CHECK(false);
  40   }
  41   // Sanity check alignment just to be safe.
  42   DCHECK_EQ(reinterpret_cast<uintptr_t>(ptr) & (alignment - 1), 0U);
  43   return ptr;
  44 }
  45
  46 }  // namespace base