ec6e3b745694a0f56b8991fb06f64081ebaa5c71
[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 AVUTIL_MEM_H
27 #define AVUTIL_MEM_H
28
29 #include "common.h"
30
31 #if defined(__ICC) || defined(__SUNPRO_C)
32 #define DECLARE_ALIGNED(n,t,v) t v __attribute__ ((aligned (n)))
33 #define DECLARE_ASM_CONST(n,t,v) const t __attribute__ ((aligned (n))) v
34 #elif defined(__GNUC__)
35 #define DECLARE_ALIGNED(n,t,v) t v __attribute__ ((aligned (n)))
36 #define DECLARE_ASM_CONST(n,t,v) static const t v attribute_used __attribute__ ((aligned (n)))
37 #elif defined(_MSC_VER)
38 #define DECLARE_ALIGNED(n,t,v) __declspec(align(n)) t v
39 #define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v
40 #elif HAVE_INLINE_ASM
41 #error The asm code needs alignment, but we do not know how to do it for this compiler.
42 #else
43 #define DECLARE_ALIGNED(n,t,v) t v
44 #define DECLARE_ASM_CONST(n,t,v) static const t v
45 #endif
46
47 #if AV_GCC_VERSION_AT_LEAST(3,1)
48 #define av_malloc_attrib __attribute__((__malloc__))
49 #else
50 #define av_malloc_attrib
51 #endif
52
53 #if (!defined(__ICC) || __ICC > 1100) && AV_GCC_VERSION_AT_LEAST(4,3)
54 #define av_alloc_size(n) __attribute__((alloc_size(n)))
55 #else
56 #define av_alloc_size(n)
57 #endif
58
59 /**
60 * Allocate a block of \p size bytes with alignment suitable for all
61 * memory accesses (including vectors if available on the CPU).
62 * @param size Size in bytes for the memory block to be allocated.
63 * @return Pointer to the allocated block, NULL if it cannot allocate
64 * it.
65 * @see av_mallocz()
66 */
67 void *av_malloc(unsigned int size) av_malloc_attrib av_alloc_size(1);
68
69 /**
70 * Allocate or reallocate a block of memory.
71 * If \p ptr is NULL and \p size > 0, allocate a new block. If \p
72 * size is zero, free the memory block pointed by \p ptr.
73 * @param size Size in bytes for the memory block to be allocated or
74 * reallocated.
75 * @param ptr Pointer to a memory block already allocated with
76 * av_malloc(z)() or av_realloc() or NULL.
77 * @return Pointer to a newly reallocated block or NULL if it cannot
78 * reallocate or the function is used to free the memory block.
79 * @see av_fast_realloc()
80 */
81 void *av_realloc(void *ptr, unsigned int size) av_alloc_size(2);
82
83 /**
84 * Free a memory block which has been allocated with av_malloc(z)() or
85 * av_realloc().
86 * @param ptr Pointer to the memory block which should be freed.
87 * @note ptr = NULL is explicitly allowed.
88 * @note It is recommended that you use av_freep() instead.
89 * @see av_freep()
90 */
91 void av_free(void *ptr);
92
93 /**
94 * Allocate a block of \p size bytes with alignment suitable for all
95 * memory accesses (including vectors if available on the CPU) and
96 * set to zeroes all the bytes of the block.
97 * @param size Size in bytes for the memory block to be allocated.
98 * @return Pointer to the allocated block, NULL if it cannot allocate
99 * it.
100 * @see av_malloc()
101 */
102 void *av_mallocz(unsigned int size) av_malloc_attrib av_alloc_size(1);
103
104 /**
105 * Duplicate the string \p s.
106 * @param s String to be duplicated.
107 * @return Pointer to a newly allocated string containing a
108 * copy of \p s or NULL if it cannot be allocated.
109 */
110 char *av_strdup(const char *s) av_malloc_attrib;
111
112 /**
113 * Free a memory block which has been allocated with av_malloc(z)() or
114 * av_realloc() and set to NULL the pointer to it.
115 * @param ptr Pointer to the pointer to the memory block which should
116 * be freed.
117 * @see av_free()
118 */
119 void av_freep(void *ptr);
120
121 #endif /* AVUTIL_MEM_H */