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
11#ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_ALIGNED_MALLOC_H_
12#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_ALIGNED_MALLOC_H_
13
14// The functions declared here
15// 1) Allocates block of aligned memory.
16// 2) Re-calculates a pointer such that it is aligned to a higher or equal
17//    address.
18// Note: alignment must be a power of two. The alignment is in bytes.
19
20#include <stddef.h>
21
22namespace webrtc {
23
24// Returns a pointer to the first boundry of |alignment| bytes following the
25// address of |ptr|.
26// Note that there is no guarantee that the memory in question is available.
27// |ptr| has no requirements other than it can't be NULL.
28void* GetRightAlign(const void* ptr, size_t alignment);
29
30// Allocates memory of |size| bytes aligned on an |alignment| boundry.
31// The return value is a pointer to the memory. Note that the memory must
32// be de-allocated using AlignedFree.
33void* AlignedMalloc(size_t size, size_t alignment);
34// De-allocates memory created using the AlignedMalloc() API.
35void AlignedFree(void* mem_block);
36
37// Templated versions to facilitate usage of aligned malloc without casting
38// to and from void*.
39template<typename T>
40T* GetRightAlign(const T* ptr, size_t alignment) {
41  return reinterpret_cast<T*>(GetRightAlign(reinterpret_cast<const void*>(ptr),
42                                            alignment));
43}
44template<typename T>
45T* AlignedMalloc(size_t size, size_t alignment) {
46  return reinterpret_cast<T*>(AlignedMalloc(size, alignment));
47}
48
49// Deleter for use with scoped_ptr. E.g., use as
50//   scoped_ptr<Foo, AlignedFreeDeleter> foo;
51struct AlignedFreeDeleter {
52  inline void operator()(void* ptr) const {
53    AlignedFree(ptr);
54  }
55};
56
57}  // namespace webrtc
58
59#endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_ALIGNED_MALLOC_H_
60