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_INCLUDE_ALIGNED_MALLOC_H_
12 #define WEBRTC_SYSTEM_WRAPPERS_INCLUDE_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
22 namespace 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.
28 void* 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.
33 void* AlignedMalloc(size_t size, size_t alignment);
34 // De-allocates memory created using the AlignedMalloc() API.
35 void AlignedFree(void* mem_block);
36
37 // Templated versions to facilitate usage of aligned malloc without casting
38 // to and from void*.
39 template<typename T>
GetRightAlign(const T * ptr,size_t alignment)40 T* GetRightAlign(const T* ptr, size_t alignment) {
41 return reinterpret_cast<T*>(GetRightAlign(reinterpret_cast<const void*>(ptr),
42 alignment));
43 }
44 template<typename T>
AlignedMalloc(size_t size,size_t alignment)45 T* 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;
51 struct AlignedFreeDeleter {
operatorAlignedFreeDeleter52 inline void operator()(void* ptr) const {
53 AlignedFree(ptr);
54 }
55 };
56
57 } // namespace webrtc
58
59 #endif // WEBRTC_SYSTEM_WRAPPERS_INCLUDE_ALIGNED_MALLOC_H_
60