aligned_malloc.h 2.0 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657
  1. /*
  2. * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
  3. *
  4. * Use of this source code is governed by a BSD-style license
  5. * that can be found in the LICENSE file in the root of the source
  6. * tree. An additional intellectual property rights grant can be found
  7. * in the file PATENTS. All contributing project authors may
  8. * be found in the AUTHORS file in the root of the source tree.
  9. */
  10. #ifndef RTC_BASE_MEMORY_ALIGNED_MALLOC_H_
  11. #define RTC_BASE_MEMORY_ALIGNED_MALLOC_H_
  12. // The functions declared here
  13. // 1) Allocates block of aligned memory.
  14. // 2) Re-calculates a pointer such that it is aligned to a higher or equal
  15. // address.
  16. // Note: alignment must be a power of two. The alignment is in bytes.
  17. #include <stddef.h>
  18. namespace webrtc {
  19. // Returns a pointer to the first boundry of |alignment| bytes following the
  20. // address of |ptr|.
  21. // Note that there is no guarantee that the memory in question is available.
  22. // |ptr| has no requirements other than it can't be NULL.
  23. void* GetRightAlign(const void* ptr, size_t alignment);
  24. // Allocates memory of |size| bytes aligned on an |alignment| boundry.
  25. // The return value is a pointer to the memory. Note that the memory must
  26. // be de-allocated using AlignedFree.
  27. void* AlignedMalloc(size_t size, size_t alignment);
  28. // De-allocates memory created using the AlignedMalloc() API.
  29. void AlignedFree(void* mem_block);
  30. // Templated versions to facilitate usage of aligned malloc without casting
  31. // to and from void*.
  32. template <typename T>
  33. T* GetRightAlign(const T* ptr, size_t alignment) {
  34. return reinterpret_cast<T*>(
  35. GetRightAlign(reinterpret_cast<const void*>(ptr), alignment));
  36. }
  37. template <typename T>
  38. T* AlignedMalloc(size_t size, size_t alignment) {
  39. return reinterpret_cast<T*>(AlignedMalloc(size, alignment));
  40. }
  41. // Deleter for use with unique_ptr. E.g., use as
  42. // std::unique_ptr<Foo, AlignedFreeDeleter> foo;
  43. struct AlignedFreeDeleter {
  44. inline void operator()(void* ptr) const { AlignedFree(ptr); }
  45. };
  46. } // namespace webrtc
  47. #endif // RTC_BASE_MEMORY_ALIGNED_MALLOC_H_