15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved.
25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be
35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file.
45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/memory/aligned_memory.h"
65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/logging.h"
85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
9f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)#if defined(OS_ANDROID)
105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <malloc.h>
115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif
125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace base {
145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void* AlignedAlloc(size_t size, size_t alignment) {
165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  DCHECK_GT(size, 0U);
175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  DCHECK_EQ(alignment & (alignment - 1), 0U);
185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  DCHECK_EQ(alignment % sizeof(void*), 0U);
195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  void* ptr = NULL;
205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#if defined(COMPILER_MSVC)
215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  ptr = _aligned_malloc(size, alignment);
22f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// Android technically supports posix_memalign(), but does not expose it in
23f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// the current version of the library headers used by Chrome.  Luckily,
24f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// memalign() on Android returns pointers which can safely be used with
25f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// free(), so we can use it instead.  Issue filed to document this:
265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// http://code.google.com/p/android/issues/detail?id=35391
27f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)#elif defined(OS_ANDROID)
285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  ptr = memalign(alignment, size);
295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#else
305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  if (posix_memalign(&ptr, alignment, size))
315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)    ptr = NULL;
325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif
335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  // Since aligned allocations may fail for non-memory related reasons, force a
345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  // crash if we encounter a failed allocation; maintaining consistent behavior
355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  // with a normal allocation failure in Chrome.
365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  if (!ptr) {
375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)    DLOG(ERROR) << "If you crashed here, your aligned allocation is incorrect: "
385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)                << "size=" << size << ", alignment=" << alignment;
395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)    CHECK(false);
405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  }
415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  // Sanity check alignment just to be safe.
425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  DCHECK_EQ(reinterpret_cast<uintptr_t>(ptr) & (alignment - 1), 0U);
435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)  return ptr;
445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}
455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)
465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}  // namespace base
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