2 * default memory allocator for libavutil
3 * Copyright (c) 2002 Fabrice Bellard
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * default memory allocator for libavutil
27 #define _XOPEN_SOURCE 600
41 /* here we can use OS-dependent allocation functions */
48 #define malloc AV_JOIN(MALLOC_PREFIX, malloc)
49 #define memalign AV_JOIN(MALLOC_PREFIX, memalign)
50 #define posix_memalign AV_JOIN(MALLOC_PREFIX, posix_memalign)
51 #define realloc AV_JOIN(MALLOC_PREFIX, realloc)
52 #define free AV_JOIN(MALLOC_PREFIX, free)
54 void *malloc(size_t size);
55 void *memalign(size_t align, size_t size);
56 int posix_memalign(void **ptr, size_t align, size_t size);
57 void *realloc(void *ptr, size_t size);
60 #endif /* MALLOC_PREFIX */
62 #define ALIGN (HAVE_AVX ? 32 : 16)
64 /* You can redefine av_malloc and av_free in your project to use your
65 memory allocator. You do not need to suppress this file because the
66 linker will do it automatically. */
68 static size_t max_alloc_size= INT_MAX;
70 void av_max_alloc(size_t max){
74 void *av_malloc(size_t size)
77 #if CONFIG_MEMALIGN_HACK
81 /* let's disallow possible ambiguous cases */
82 if (size > (max_alloc_size-32))
85 #if CONFIG_MEMALIGN_HACK
86 ptr = malloc(size+ALIGN);
89 diff= ((-(long)ptr - 1)&(ALIGN-1)) + 1;
90 ptr = (char*)ptr + diff;
91 ((char*)ptr)[-1]= diff;
92 #elif HAVE_POSIX_MEMALIGN
93 if (size) //OS X on SDK 10.6 has a broken posix_memalign implementation
94 if (posix_memalign(&ptr,ALIGN,size))
97 ptr = memalign(ALIGN,size);
99 Indeed, we should align it:
102 on 32 for 586, PPro - K6-III
103 on 64 for K7 (maybe for P3 too).
104 Because L1 and L2 caches are aligned on those values.
105 But I don't want to code such logic here!
108 For AVX ASM. SSE / NEON needs only 16.
109 Why not larger? Because I did not see a difference in benchmarks ...
111 /* benchmarks with P3
112 memalign(64)+1 3071,3051,3032
113 memalign(64)+2 3051,3032,3041
114 memalign(64)+4 2911,2896,2915
115 memalign(64)+8 2545,2554,2550
116 memalign(64)+16 2543,2572,2563
117 memalign(64)+32 2546,2545,2571
118 memalign(64)+64 2570,2533,2558
120 BTW, malloc seems to do 8-byte alignment by default here.
130 void *av_realloc(void *ptr, size_t size)
132 #if CONFIG_MEMALIGN_HACK
136 /* let's disallow possible ambiguous cases */
137 if (size > (max_alloc_size-32))
140 #if CONFIG_MEMALIGN_HACK
141 //FIXME this isn't aligned correctly, though it probably isn't needed
142 if(!ptr) return av_malloc(size);
143 diff= ((char*)ptr)[-1];
144 ptr= realloc((char*)ptr - diff, size + diff);
145 if(ptr) ptr = (char*)ptr + diff;
148 return realloc(ptr, size + !size);
152 void *av_realloc_f(void *ptr, size_t nelem, size_t elsize)
157 if (av_size_mult(elsize, nelem, &size)) {
161 r = av_realloc(ptr, size);
167 void av_free(void *ptr)
169 #if CONFIG_MEMALIGN_HACK
171 free((char*)ptr - ((char*)ptr)[-1]);
177 void av_freep(void *arg)
179 void **ptr= (void**)arg;
184 void *av_mallocz(size_t size)
186 void *ptr = av_malloc(size);
188 memset(ptr, 0, size);
192 void *av_calloc(size_t nmemb, size_t size)
194 if (size <= 0 || nmemb >= INT_MAX / size)
196 return av_mallocz(nmemb * size);
199 char *av_strdup(const char *s)
203 int len = strlen(s) + 1;
204 ptr = av_malloc(len);
211 /* add one element to a dynamic array */
212 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem)
214 /* see similar ffmpeg.c:grow_array() */
219 tab = *(intptr_t**)tab_ptr;
220 if ((nb & (nb - 1)) == 0) {
225 tab = av_realloc(tab, nb_alloc * sizeof(intptr_t));
226 *(intptr_t**)tab_ptr = tab;
228 tab[nb++] = (intptr_t)elem;