e50553aefee85bfdd3f7c382fb4200924206bb6a
[libav.git] / libavutil / mem.h
1 /*
2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 /**
22 * @file libavutil/mem.h
23 * memory handling functions
24 */
25
26 #ifndef AVUTIL_MEM_H
27 #define AVUTIL_MEM_H
28
29 #include "common.h"
30
31 #if AV_GCC_VERSION_AT_LEAST(3,1)
32 #define av_malloc_attrib __attribute__((__malloc__))
33 #else
34 #define av_malloc_attrib
35 #endif
36
37 #if (!defined(__ICC) || __ICC > 1100) && AV_GCC_VERSION_AT_LEAST(4,3)
38 #define av_alloc_size(n) __attribute__((alloc_size(n)))
39 #else
40 #define av_alloc_size(n)
41 #endif
42
43 /**
44 * Allocates a block of \p size bytes with alignment suitable for all
45 * memory accesses (including vectors if available on the CPU).
46 * @param size Size in bytes for the memory block to be allocated.
47 * @return Pointer to the allocated block, NULL if the block cannot
48 * be allocated.
49 * @see av_mallocz()
50 */
51 void *av_malloc(unsigned int size) av_malloc_attrib av_alloc_size(1);
52
53 /**
54 * Allocates or reallocates a block of memory.
55 * If \p ptr is NULL and \p size > 0, allocates a new block. If \p
56 * size is zero, frees the memory block pointed to by \p ptr.
57 * @param size Size in bytes for the memory block to be allocated or
58 * reallocated.
59 * @param ptr Pointer to a memory block already allocated with
60 * av_malloc(z)() or av_realloc() or NULL.
61 * @return Pointer to a newly reallocated block or NULL if the block
62 * cannot be reallocated or the function is used to free the memory block.
63 * @see av_fast_realloc()
64 */
65 void *av_realloc(void *ptr, unsigned int size) av_alloc_size(2);
66
67 /**
68 * Frees a memory block which has been allocated with av_malloc(z)() or
69 * av_realloc().
70 * @param ptr Pointer to the memory block which should be freed.
71 * @note ptr = NULL is explicitly allowed.
72 * @note It is recommended that you use av_freep() instead.
73 * @see av_freep()
74 */
75 void av_free(void *ptr);
76
77 /**
78 * Allocates a block of \p size bytes with alignment suitable for all
79 * memory accesses (including vectors if available on the CPU) and
80 * zeroes all the bytes of the block.
81 * @param size Size in bytes for the memory block to be allocated.
82 * @return Pointer to the allocated block, NULL if it cannot be allocated.
83 * @see av_malloc()
84 */
85 void *av_mallocz(unsigned int size) av_malloc_attrib av_alloc_size(1);
86
87 /**
88 * Duplicates the string \p s.
89 * @param s string to be duplicated
90 * @return Pointer to a newly allocated string containing a
91 * copy of \p s or NULL if the string cannot be allocated.
92 */
93 char *av_strdup(const char *s) av_malloc_attrib;
94
95 /**
96 * Frees a memory block which has been allocated with av_malloc(z)() or
97 * av_realloc() and set the pointer pointing to it to NULL.
98 * @param ptr Pointer to the pointer to the memory block which should
99 * be freed.
100 * @see av_free()
101 */
102 void av_freep(void *ptr);
103
104 #endif /* AVUTIL_MEM_H */