f8df42cfe79093a0055fe4da8a4bae5d5ceef0f6
[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 mem.h
23 * Memory handling functions.
24 */
25
26 #ifndef FFMPEG_MEM_H
27 #define FFMPEG_MEM_H
28
29 #ifdef __ICC
30 #define DECLARE_ALIGNED(n,t,v) t v __attribute__ ((aligned (n)))
31 #define DECLARE_ASM_CONST(n,t,v) const t __attribute__ ((aligned (n))) v
32 #elif defined(__GNUC__)
33 #define DECLARE_ALIGNED(n,t,v) t v __attribute__ ((aligned (n)))
34 #define DECLARE_ASM_CONST(n,t,v) static const t v attribute_used __attribute__ ((aligned (n)))
35 #elif defined(_MSC_VER)
36 #define DECLARE_ALIGNED(n,t,v) __declspec(align(n)) t v
37 #define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v
38 #elif defined(HAVE_INLINE_ASM)
39 #error The asm code needs alignment, but we do not know how to do it for this compiler.
40 #else
41 #define DECLARE_ALIGNED(n,t,v) t v
42 #define DECLARE_ASM_CONST(n,t,v) static const t v
43 #endif
44
45 /**
46 * Allocate a block of \p size bytes with alignment suitable for all
47 * memory accesses (including vectors if available on the CPU).
48 * @param size Size in bytes for the memory block to be allocated.
49 * @return Pointer to the allocated block, NULL if it cannot allocate
50 * it.
51 * @see av_mallocz()
52 */
53 void *av_malloc(unsigned int size);
54
55 /**
56 * Allocate or reallocate a block of memory.
57 * If \p ptr is NULL and \p size > 0, allocate a new block. If \p
58 * size is zero, free the memory block pointed by \p ptr.
59 * @param size Size in bytes for the memory block to be allocated or
60 * reallocated.
61 * @param ptr Pointer to a memory block already allocated with
62 * av_malloc(z)() or av_realloc() or NULL.
63 * @return Pointer to a newly reallocated block or NULL if it cannot
64 * reallocate or the function is used to free the memory block.
65 * @see av_fast_realloc()
66 */
67 void *av_realloc(void *ptr, unsigned int size);
68
69 /**
70 * Free a memory block which has been allocated with av_malloc(z)() or
71 * av_realloc().
72 * @param ptr Pointer to the memory block which should be freed.
73 * @note ptr = NULL is explicitly allowed.
74 * @note It is recommended that you use av_freep() instead.
75 * @see av_freep()
76 */
77 void av_free(void *ptr);
78
79 /**
80 * Allocate a block of \p size bytes with alignment suitable for all
81 * memory accesses (including vectors if available on the CPU) and
82 * set to zeroes all the bytes of the block.
83 * @param size Size in bytes for the memory block to be allocated.
84 * @return Pointer to the allocated block, NULL if it cannot allocate
85 * it.
86 * @see av_malloc()
87 */
88 void *av_mallocz(unsigned int size);
89
90 /**
91 * Duplicate the string \p s.
92 * @param s String to be duplicated.
93 * @return Pointer to a newly allocated string containing a
94 * copy of \p s or NULL if it cannot be allocated.
95 */
96 char *av_strdup(const char *s);
97
98 /**
99 * Free a memory block which has been allocated with av_malloc(z)() or
100 * av_realloc() and set to NULL the pointer to it.
101 * @param ptr Pointer to the pointer to the memory block which should
102 * be freed.
103 * @see av_free()
104 */
105 void av_freep(void *ptr);
106
107 #endif /* FFMPEG_MEM_H */