1 /*
2 * default memory allocator for libavutil
3 * Copyright (c) 2002 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 /**
23 * @file
24 * default memory allocator for libavutil
25 */
26
27 #define _XOPEN_SOURCE 600
28
29 #include "config.h"
30
31 #include <limits.h>
32 #include <stdint.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #if HAVE_MALLOC_H
36 #include <malloc.h>
37 #endif
38
39 #include "avassert.h"
40 #include "avutil.h"
41 #include "common.h"
42 #include "dynarray.h"
43 #include "intreadwrite.h"
44 #include "mem.h"
45
46 #ifdef MALLOC_PREFIX
47
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)
53
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);
58 void free(void *ptr);
59
60 #endif /* MALLOC_PREFIX */
61
62 #include "mem_internal.h"
63
64 #define ALIGN (HAVE_AVX ? 32 : 16)
65
66 /* NOTE: if you want to override these functions with your own
67 * implementations (not recommended) you have to link libav* as
68 * dynamic libraries and remove -Wl,-Bsymbolic from the linker flags.
69 * Note that this will cost performance. */
70
71 static size_t max_alloc_size= INT_MAX;
72
av_max_alloc(size_t max)73 void av_max_alloc(size_t max){
74 max_alloc_size = max;
75 }
76
av_malloc(size_t size)77 void *av_malloc(size_t size)
78 {
79 void *ptr = NULL;
80 #if CONFIG_MEMALIGN_HACK
81 long diff;
82 #endif
83
84 /* let's disallow possibly ambiguous cases */
85 if (size > (max_alloc_size - 32))
86 return NULL;
87
88 #if CONFIG_MEMALIGN_HACK
89 ptr = malloc(size + ALIGN);
90 if (!ptr)
91 return ptr;
92 diff = ((~(long)ptr)&(ALIGN - 1)) + 1;
93 ptr = (char *)ptr + diff;
94 ((char *)ptr)[-1] = diff;
95 #elif HAVE_POSIX_MEMALIGN
96 if (size) //OS X on SDK 10.6 has a broken posix_memalign implementation
97 if (posix_memalign(&ptr, ALIGN, size))
98 ptr = NULL;
99 #elif HAVE_ALIGNED_MALLOC
100 ptr = _aligned_malloc(size, ALIGN);
101 #elif HAVE_MEMALIGN
102 #ifndef __DJGPP__
103 ptr = memalign(ALIGN, size);
104 #else
105 ptr = memalign(size, ALIGN);
106 #endif
107 /* Why 64?
108 * Indeed, we should align it:
109 * on 4 for 386
110 * on 16 for 486
111 * on 32 for 586, PPro - K6-III
112 * on 64 for K7 (maybe for P3 too).
113 * Because L1 and L2 caches are aligned on those values.
114 * But I don't want to code such logic here!
115 */
116 /* Why 32?
117 * For AVX ASM. SSE / NEON needs only 16.
118 * Why not larger? Because I did not see a difference in benchmarks ...
119 */
120 /* benchmarks with P3
121 * memalign(64) + 1 3071, 3051, 3032
122 * memalign(64) + 2 3051, 3032, 3041
123 * memalign(64) + 4 2911, 2896, 2915
124 * memalign(64) + 8 2545, 2554, 2550
125 * memalign(64) + 16 2543, 2572, 2563
126 * memalign(64) + 32 2546, 2545, 2571
127 * memalign(64) + 64 2570, 2533, 2558
128 *
129 * BTW, malloc seems to do 8-byte alignment by default here.
130 */
131 #else
132 ptr = malloc(size);
133 #endif
134 if(!ptr && !size) {
135 size = 1;
136 ptr= av_malloc(1);
137 }
138 #if CONFIG_MEMORY_POISONING
139 if (ptr)
140 memset(ptr, FF_MEMORY_POISON, size);
141 #endif
142 return ptr;
143 }
144
av_realloc(void * ptr,size_t size)145 void *av_realloc(void *ptr, size_t size)
146 {
147 #if CONFIG_MEMALIGN_HACK
148 int diff;
149 #endif
150
151 /* let's disallow possibly ambiguous cases */
152 if (size > (max_alloc_size - 32))
153 return NULL;
154
155 #if CONFIG_MEMALIGN_HACK
156 //FIXME this isn't aligned correctly, though it probably isn't needed
157 if (!ptr)
158 return av_malloc(size);
159 diff = ((char *)ptr)[-1];
160 av_assert0(diff>0 && diff<=ALIGN);
161 ptr = realloc((char *)ptr - diff, size + diff);
162 if (ptr)
163 ptr = (char *)ptr + diff;
164 return ptr;
165 #elif HAVE_ALIGNED_MALLOC
166 return _aligned_realloc(ptr, size + !size, ALIGN);
167 #else
168 return realloc(ptr, size + !size);
169 #endif
170 }
171
av_realloc_f(void * ptr,size_t nelem,size_t elsize)172 void *av_realloc_f(void *ptr, size_t nelem, size_t elsize)
173 {
174 size_t size;
175 void *r;
176
177 if (av_size_mult(elsize, nelem, &size)) {
178 av_free(ptr);
179 return NULL;
180 }
181 r = av_realloc(ptr, size);
182 if (!r && size)
183 av_free(ptr);
184 return r;
185 }
186
av_reallocp(void * ptr,size_t size)187 int av_reallocp(void *ptr, size_t size)
188 {
189 void *val;
190
191 if (!size) {
192 av_freep(ptr);
193 return 0;
194 }
195
196 memcpy(&val, ptr, sizeof(val));
197 val = av_realloc(val, size);
198
199 if (!val) {
200 av_freep(ptr);
201 return AVERROR(ENOMEM);
202 }
203
204 memcpy(ptr, &val, sizeof(val));
205 return 0;
206 }
207
av_realloc_array(void * ptr,size_t nmemb,size_t size)208 void *av_realloc_array(void *ptr, size_t nmemb, size_t size)
209 {
210 if (!size || nmemb >= INT_MAX / size)
211 return NULL;
212 return av_realloc(ptr, nmemb * size);
213 }
214
av_reallocp_array(void * ptr,size_t nmemb,size_t size)215 int av_reallocp_array(void *ptr, size_t nmemb, size_t size)
216 {
217 void *val;
218
219 memcpy(&val, ptr, sizeof(val));
220 val = av_realloc_f(val, nmemb, size);
221 memcpy(ptr, &val, sizeof(val));
222 if (!val && nmemb && size)
223 return AVERROR(ENOMEM);
224
225 return 0;
226 }
227
av_free(void * ptr)228 void av_free(void *ptr)
229 {
230 #if CONFIG_MEMALIGN_HACK
231 if (ptr) {
232 int v= ((char *)ptr)[-1];
233 av_assert0(v>0 && v<=ALIGN);
234 free((char *)ptr - v);
235 }
236 #elif HAVE_ALIGNED_MALLOC
237 _aligned_free(ptr);
238 #else
239 free(ptr);
240 #endif
241 }
242
av_freep(void * arg)243 void av_freep(void *arg)
244 {
245 void *val;
246
247 memcpy(&val, arg, sizeof(val));
248 memcpy(arg, &(void *){ NULL }, sizeof(val));
249 av_free(val);
250 }
251
av_mallocz(size_t size)252 void *av_mallocz(size_t size)
253 {
254 void *ptr = av_malloc(size);
255 if (ptr)
256 memset(ptr, 0, size);
257 return ptr;
258 }
259
av_calloc(size_t nmemb,size_t size)260 void *av_calloc(size_t nmemb, size_t size)
261 {
262 if (size <= 0 || nmemb >= INT_MAX / size)
263 return NULL;
264 return av_mallocz(nmemb * size);
265 }
266
av_strdup(const char * s)267 char *av_strdup(const char *s)
268 {
269 char *ptr = NULL;
270 if (s) {
271 size_t len = strlen(s) + 1;
272 ptr = av_realloc(NULL, len);
273 if (ptr)
274 memcpy(ptr, s, len);
275 }
276 return ptr;
277 }
278
av_strndup(const char * s,size_t len)279 char *av_strndup(const char *s, size_t len)
280 {
281 char *ret = NULL, *end;
282
283 if (!s)
284 return NULL;
285
286 end = memchr(s, 0, len);
287 if (end)
288 len = end - s;
289
290 ret = av_realloc(NULL, len + 1);
291 if (!ret)
292 return NULL;
293
294 memcpy(ret, s, len);
295 ret[len] = 0;
296 return ret;
297 }
298
av_memdup(const void * p,size_t size)299 void *av_memdup(const void *p, size_t size)
300 {
301 void *ptr = NULL;
302 if (p) {
303 ptr = av_malloc(size);
304 if (ptr)
305 memcpy(ptr, p, size);
306 }
307 return ptr;
308 }
309
av_dynarray_add_nofree(void * tab_ptr,int * nb_ptr,void * elem)310 int av_dynarray_add_nofree(void *tab_ptr, int *nb_ptr, void *elem)
311 {
312 void **tab;
313 memcpy(&tab, tab_ptr, sizeof(tab));
314
315 AV_DYNARRAY_ADD(INT_MAX, sizeof(*tab), tab, *nb_ptr, {
316 tab[*nb_ptr] = elem;
317 memcpy(tab_ptr, &tab, sizeof(tab));
318 }, {
319 return AVERROR(ENOMEM);
320 });
321 return 0;
322 }
323
av_dynarray_add(void * tab_ptr,int * nb_ptr,void * elem)324 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem)
325 {
326 void **tab;
327 memcpy(&tab, tab_ptr, sizeof(tab));
328
329 AV_DYNARRAY_ADD(INT_MAX, sizeof(*tab), tab, *nb_ptr, {
330 tab[*nb_ptr] = elem;
331 memcpy(tab_ptr, &tab, sizeof(tab));
332 }, {
333 *nb_ptr = 0;
334 av_freep(tab_ptr);
335 });
336 }
337
av_dynarray2_add(void ** tab_ptr,int * nb_ptr,size_t elem_size,const uint8_t * elem_data)338 void *av_dynarray2_add(void **tab_ptr, int *nb_ptr, size_t elem_size,
339 const uint8_t *elem_data)
340 {
341 uint8_t *tab_elem_data = NULL;
342
343 AV_DYNARRAY_ADD(INT_MAX, elem_size, *tab_ptr, *nb_ptr, {
344 tab_elem_data = (uint8_t *)*tab_ptr + (*nb_ptr) * elem_size;
345 if (elem_data)
346 memcpy(tab_elem_data, elem_data, elem_size);
347 else if (CONFIG_MEMORY_POISONING)
348 memset(tab_elem_data, FF_MEMORY_POISON, elem_size);
349 }, {
350 av_freep(tab_ptr);
351 *nb_ptr = 0;
352 });
353 return tab_elem_data;
354 }
355
fill16(uint8_t * dst,int len)356 static void fill16(uint8_t *dst, int len)
357 {
358 uint32_t v = AV_RN16(dst - 2);
359
360 v |= v << 16;
361
362 while (len >= 4) {
363 AV_WN32(dst, v);
364 dst += 4;
365 len -= 4;
366 }
367
368 while (len--) {
369 *dst = dst[-2];
370 dst++;
371 }
372 }
373
fill24(uint8_t * dst,int len)374 static void fill24(uint8_t *dst, int len)
375 {
376 #if HAVE_BIGENDIAN
377 uint32_t v = AV_RB24(dst - 3);
378 uint32_t a = v << 8 | v >> 16;
379 uint32_t b = v << 16 | v >> 8;
380 uint32_t c = v << 24 | v;
381 #else
382 uint32_t v = AV_RL24(dst - 3);
383 uint32_t a = v | v << 24;
384 uint32_t b = v >> 8 | v << 16;
385 uint32_t c = v >> 16 | v << 8;
386 #endif
387
388 while (len >= 12) {
389 AV_WN32(dst, a);
390 AV_WN32(dst + 4, b);
391 AV_WN32(dst + 8, c);
392 dst += 12;
393 len -= 12;
394 }
395
396 if (len >= 4) {
397 AV_WN32(dst, a);
398 dst += 4;
399 len -= 4;
400 }
401
402 if (len >= 4) {
403 AV_WN32(dst, b);
404 dst += 4;
405 len -= 4;
406 }
407
408 while (len--) {
409 *dst = dst[-3];
410 dst++;
411 }
412 }
413
fill32(uint8_t * dst,int len)414 static void fill32(uint8_t *dst, int len)
415 {
416 uint32_t v = AV_RN32(dst - 4);
417
418 while (len >= 4) {
419 AV_WN32(dst, v);
420 dst += 4;
421 len -= 4;
422 }
423
424 while (len--) {
425 *dst = dst[-4];
426 dst++;
427 }
428 }
429
av_memcpy_backptr(uint8_t * dst,int back,int cnt)430 void av_memcpy_backptr(uint8_t *dst, int back, int cnt)
431 {
432 const uint8_t *src = &dst[-back];
433 if (!back)
434 return;
435
436 if (back == 1) {
437 memset(dst, *src, cnt);
438 } else if (back == 2) {
439 fill16(dst, cnt);
440 } else if (back == 3) {
441 fill24(dst, cnt);
442 } else if (back == 4) {
443 fill32(dst, cnt);
444 } else {
445 if (cnt >= 16) {
446 int blocklen = back;
447 while (cnt > blocklen) {
448 memcpy(dst, src, blocklen);
449 dst += blocklen;
450 cnt -= blocklen;
451 blocklen <<= 1;
452 }
453 memcpy(dst, src, cnt);
454 return;
455 }
456 if (cnt >= 8) {
457 AV_COPY32U(dst, src);
458 AV_COPY32U(dst + 4, src + 4);
459 src += 8;
460 dst += 8;
461 cnt -= 8;
462 }
463 if (cnt >= 4) {
464 AV_COPY32U(dst, src);
465 src += 4;
466 dst += 4;
467 cnt -= 4;
468 }
469 if (cnt >= 2) {
470 AV_COPY16U(dst, src);
471 src += 2;
472 dst += 2;
473 cnt -= 2;
474 }
475 if (cnt)
476 *dst = *src;
477 }
478 }
479
av_fast_realloc(void * ptr,unsigned int * size,size_t min_size)480 void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size)
481 {
482 if (min_size < *size)
483 return ptr;
484
485 min_size = FFMAX(min_size + min_size / 16 + 32, min_size);
486
487 ptr = av_realloc(ptr, min_size);
488 /* we could set this to the unmodified min_size but this is safer
489 * if the user lost the ptr and uses NULL now
490 */
491 if (!ptr)
492 min_size = 0;
493
494 *size = min_size;
495
496 return ptr;
497 }
498
av_fast_malloc(void * ptr,unsigned int * size,size_t min_size)499 void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size)
500 {
501 ff_fast_malloc(ptr, size, min_size, 0);
502 }
503
av_fast_mallocz(void * ptr,unsigned int * size,size_t min_size)504 void av_fast_mallocz(void *ptr, unsigned int *size, size_t min_size)
505 {
506 ff_fast_malloc(ptr, size, min_size, 1);
507 }
508