mm_malloc.h revision 208954 
1/*===---- mm_malloc.h - Allocating and Freeing Aligned Memory Blocks -------===
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to deal
5 * in the Software without restriction, including without limitation the rights
6 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7 * copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
9 *
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
19 * THE SOFTWARE.
20 *
21 *===-----------------------------------------------------------------------===
22 */
23
24#ifndef __MM_MALLOC_H
25#define __MM_MALLOC_H
26
27#include <errno.h>
28#include <stdlib.h>
29
30static __inline__ void *__attribute__((__always_inline__, __nodebug__))
31_mm_malloc(size_t size, size_t align)
32{
33  if (align & (align - 1)) {
34    errno = EINVAL;
35    return 0;
36  }
37
38  if (!size)
39    return 0;
40
41  if (align < 2 * sizeof(void *))
42    align = 2 * sizeof(void *);
43
44  void *mallocedMemory = malloc(size + align);
45  if (!mallocedMemory)
46    return 0;
47
48  void *alignedMemory =
49    (void *)(((size_t)mallocedMemory + align) & ~((size_t)align - 1));
50  ((void **)alignedMemory)[-1] = mallocedMemory;
51
52  return alignedMemory;
53}
54
55static __inline__ void __attribute__((__always_inline__, __nodebug__))
56_mm_free(void *p)
57{
58  if (p)
59    free(((void **)p)[-1]);
60}
61
62#endif /* __MM_MALLOC_H */
63