mem: Don't abort on av_malloc(0) in debug mode
[libav.git] / libavutil / mem.c
CommitLineData
d01fe86d 1/*
cea8f6f3 2 * default memory allocator for libavutil
406792e7 3 * Copyright (c) 2002 Fabrice Bellard
d01fe86d 4 *
2912e87a 5 * This file is part of Libav.
b78e7197 6 *
2912e87a 7 * Libav is free software; you can redistribute it and/or
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8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
b78e7197 10 * version 2.1 of the License, or (at your option) any later version.
d01fe86d 11 *
2912e87a 12 * Libav is distributed in the hope that it will be useful,
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13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
2912e87a 18 * License along with Libav; if not, write to the Free Software
5509bffa 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
d01fe86d 20 */
115329f1 21
983e3246 22/**
ba87f080 23 * @file
89c9ff50 24 * default memory allocator for libavutil
983e3246 25 */
115329f1 26
dfcb6b56 27#include "config.h"
8e1e6f31 28
dfcb6b56 29#include <limits.h>
1f91cdce 30#include <stdlib.h>
dfcb6b56 31#include <string.h>
b250f9c6 32#if HAVE_MALLOC_H
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33#include <malloc.h>
34#endif
35
4ae40685 36#include "avutil.h"
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37#include "mem.h"
38
89c9ff50 39/* here we can use OS-dependent allocation functions */
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40#undef free
41#undef malloc
42#undef realloc
43
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44#ifdef MALLOC_PREFIX
45
46#define malloc AV_JOIN(MALLOC_PREFIX, malloc)
47#define memalign AV_JOIN(MALLOC_PREFIX, memalign)
48#define posix_memalign AV_JOIN(MALLOC_PREFIX, posix_memalign)
49#define realloc AV_JOIN(MALLOC_PREFIX, realloc)
50#define free AV_JOIN(MALLOC_PREFIX, free)
51
52void *malloc(size_t size);
53void *memalign(size_t align, size_t size);
54int posix_memalign(void **ptr, size_t align, size_t size);
55void *realloc(void *ptr, size_t size);
56void free(void *ptr);
57
58#endif /* MALLOC_PREFIX */
59
89c9ff50 60/* You can redefine av_malloc and av_free in your project to use your
d01fe86d 61 memory allocator. You do not need to suppress this file because the
89c9ff50 62 linker will do it automatically. */
d01fe86d 63
490a022d 64void *av_malloc(size_t size)
d01fe86d 65{
1f91cdce 66 void *ptr = NULL;
b250f9c6 67#if CONFIG_MEMALIGN_HACK
ed96aeea 68 long diff;
88730be6 69#endif
0ecca7a4 70
7d77d5f6 71 /* let's disallow possible ambiguous cases */
14f063d2 72 if (size > (INT_MAX-32) || !size)
0ecca7a4 73 return NULL;
115329f1 74
b250f9c6 75#if CONFIG_MEMALIGN_HACK
13dfce3d 76 ptr = malloc(size+32);
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77 if(!ptr)
78 return ptr;
13dfce3d 79 diff= ((-(long)ptr - 1)&31) + 1;
90d30570 80 ptr = (char*)ptr + diff;
da9b170c 81 ((char*)ptr)[-1]= diff;
b250f9c6 82#elif HAVE_POSIX_MEMALIGN
13dfce3d 83 if (posix_memalign(&ptr,32,size))
a90de11d 84 ptr = NULL;
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85#elif HAVE_ALIGNED_MALLOC
86 ptr = _aligned_malloc(size, 32);
b250f9c6 87#elif HAVE_MEMALIGN
13dfce3d 88 ptr = memalign(32,size);
115329f1 89 /* Why 64?
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90 Indeed, we should align it:
91 on 4 for 386
92 on 16 for 486
89c9ff50 93 on 32 for 586, PPro - K6-III
bb270c08 94 on 64 for K7 (maybe for P3 too).
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95 Because L1 and L2 caches are aligned on those values.
96 But I don't want to code such logic here!
97 */
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98 /* Why 32?
99 For AVX ASM. SSE / NEON needs only 16.
2cab6401 100 Why not larger? Because I did not see a difference in benchmarks ...
8f2b21a8 101 */
89c9ff50 102 /* benchmarks with P3
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103 memalign(64)+1 3071,3051,3032
104 memalign(64)+2 3051,3032,3041
105 memalign(64)+4 2911,2896,2915
106 memalign(64)+8 2545,2554,2550
107 memalign(64)+16 2543,2572,2563
108 memalign(64)+32 2546,2545,2571
109 memalign(64)+64 2570,2533,2558
115329f1 110
89c9ff50 111 BTW, malloc seems to do 8-byte alignment by default here.
8f2b21a8 112 */
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113#else
114 ptr = malloc(size);
115#endif
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116 return ptr;
117}
118
490a022d 119void *av_realloc(void *ptr, size_t size)
8e1e6f31 120{
b250f9c6 121#if CONFIG_MEMALIGN_HACK
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122 int diff;
123#endif
88730be6 124
7d77d5f6 125 /* let's disallow possible ambiguous cases */
a9493601 126 if(size > (INT_MAX-16) )
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127 return NULL;
128
b250f9c6 129#if CONFIG_MEMALIGN_HACK
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130 //FIXME this isn't aligned correctly, though it probably isn't needed
131 if(!ptr) return av_malloc(size);
132 diff= ((char*)ptr)[-1];
90d30570 133 return (char*)realloc((char*)ptr - diff, size + diff) + diff;
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134#elif HAVE_ALIGNED_MALLOC
135 return _aligned_realloc(ptr, size, 32);
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136#else
137 return realloc(ptr, size);
da9b170c 138#endif
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139}
140
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141void av_free(void *ptr)
142{
b250f9c6 143#if CONFIG_MEMALIGN_HACK
dc75d6db 144 if (ptr)
90d30570 145 free((char*)ptr - ((char*)ptr)[-1]);
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146#elif HAVE_ALIGNED_MALLOC
147 _aligned_free(ptr);
da9b170c 148#else
dc75d6db 149 free(ptr);
da9b170c 150#endif
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151}
152
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153void av_freep(void *arg)
154{
155 void **ptr= (void**)arg;
156 av_free(*ptr);
157 *ptr = NULL;
158}
159
490a022d 160void *av_mallocz(size_t size)
79e47000 161{
11362767 162 void *ptr = av_malloc(size);
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163 if (ptr)
164 memset(ptr, 0, size);
165 return ptr;
166}
167
168char *av_strdup(const char *s)
169{
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170 char *ptr= NULL;
171 if(s){
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172 int len = strlen(s) + 1;
173 ptr = av_malloc(len);
174 if (ptr)
175 memcpy(ptr, s, len);
fdf35f26 176 }
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177 return ptr;
178}