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mem.c
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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 
73 void av_max_alloc(size_t max){
74  max_alloc_size = max;
75 }
76 
77 void *av_malloc(size_t size)
78 {
79  void *ptr = NULL;
80 
81  /* let's disallow possibly ambiguous cases */
82  if (size > (max_alloc_size - 32))
83  return NULL;
84 
85 #if HAVE_POSIX_MEMALIGN
86  if (size) //OS X on SDK 10.6 has a broken posix_memalign implementation
87  if (posix_memalign(&ptr, ALIGN, size))
88  ptr = NULL;
89 #elif HAVE_ALIGNED_MALLOC
90  ptr = _aligned_malloc(size, ALIGN);
91 #elif HAVE_MEMALIGN
92 #ifndef __DJGPP__
93  ptr = memalign(ALIGN, size);
94 #else
95  ptr = memalign(size, ALIGN);
96 #endif
97  /* Why 64?
98  * Indeed, we should align it:
99  * on 4 for 386
100  * on 16 for 486
101  * on 32 for 586, PPro - K6-III
102  * on 64 for K7 (maybe for P3 too).
103  * Because L1 and L2 caches are aligned on those values.
104  * But I don't want to code such logic here!
105  */
106  /* Why 32?
107  * For AVX ASM. SSE / NEON needs only 16.
108  * Why not larger? Because I did not see a difference in benchmarks ...
109  */
110  /* benchmarks with P3
111  * memalign(64) + 1 3071, 3051, 3032
112  * memalign(64) + 2 3051, 3032, 3041
113  * memalign(64) + 4 2911, 2896, 2915
114  * memalign(64) + 8 2545, 2554, 2550
115  * memalign(64) + 16 2543, 2572, 2563
116  * memalign(64) + 32 2546, 2545, 2571
117  * memalign(64) + 64 2570, 2533, 2558
118  *
119  * BTW, malloc seems to do 8-byte alignment by default here.
120  */
121 #else
122  ptr = malloc(size);
123 #endif
124  if(!ptr && !size) {
125  size = 1;
126  ptr= av_malloc(1);
127  }
128 #if CONFIG_MEMORY_POISONING
129  if (ptr)
130  memset(ptr, FF_MEMORY_POISON, size);
131 #endif
132  return ptr;
133 }
134 
135 void *av_realloc(void *ptr, size_t size)
136 {
137  /* let's disallow possibly ambiguous cases */
138  if (size > (max_alloc_size - 32))
139  return NULL;
140 
141 #if HAVE_ALIGNED_MALLOC
142  return _aligned_realloc(ptr, size + !size, ALIGN);
143 #else
144  return realloc(ptr, size + !size);
145 #endif
146 }
147 
148 void *av_realloc_f(void *ptr, size_t nelem, size_t elsize)
149 {
150  size_t size;
151  void *r;
152 
153  if (av_size_mult(elsize, nelem, &size)) {
154  av_free(ptr);
155  return NULL;
156  }
157  r = av_realloc(ptr, size);
158  if (!r)
159  av_free(ptr);
160  return r;
161 }
162 
163 int av_reallocp(void *ptr, size_t size)
164 {
165  void *val;
166 
167  if (!size) {
168  av_freep(ptr);
169  return 0;
170  }
171 
172  memcpy(&val, ptr, sizeof(val));
173  val = av_realloc(val, size);
174 
175  if (!val) {
176  av_freep(ptr);
177  return AVERROR(ENOMEM);
178  }
179 
180  memcpy(ptr, &val, sizeof(val));
181  return 0;
182 }
183 
184 void *av_realloc_array(void *ptr, size_t nmemb, size_t size)
185 {
186  if (!size || nmemb >= INT_MAX / size)
187  return NULL;
188  return av_realloc(ptr, nmemb * size);
189 }
190 
191 int av_reallocp_array(void *ptr, size_t nmemb, size_t size)
192 {
193  void *val;
194 
195  memcpy(&val, ptr, sizeof(val));
196  val = av_realloc_f(val, nmemb, size);
197  memcpy(ptr, &val, sizeof(val));
198  if (!val && nmemb && size)
199  return AVERROR(ENOMEM);
200 
201  return 0;
202 }
203 
204 void av_free(void *ptr)
205 {
206 #if HAVE_ALIGNED_MALLOC
207  _aligned_free(ptr);
208 #else
209  free(ptr);
210 #endif
211 }
212 
213 void av_freep(void *arg)
214 {
215  void *val;
216 
217  memcpy(&val, arg, sizeof(val));
218  memcpy(arg, &(void *){ NULL }, sizeof(val));
219  av_free(val);
220 }
221 
222 void *av_mallocz(size_t size)
223 {
224  void *ptr = av_malloc(size);
225  if (ptr)
226  memset(ptr, 0, size);
227  return ptr;
228 }
229 
230 void *av_calloc(size_t nmemb, size_t size)
231 {
232  if (size <= 0 || nmemb >= INT_MAX / size)
233  return NULL;
234  return av_mallocz(nmemb * size);
235 }
236 
237 char *av_strdup(const char *s)
238 {
239  char *ptr = NULL;
240  if (s) {
241  size_t len = strlen(s) + 1;
242  ptr = av_realloc(NULL, len);
243  if (ptr)
244  memcpy(ptr, s, len);
245  }
246  return ptr;
247 }
248 
249 char *av_strndup(const char *s, size_t len)
250 {
251  char *ret = NULL, *end;
252 
253  if (!s)
254  return NULL;
255 
256  end = memchr(s, 0, len);
257  if (end)
258  len = end - s;
259 
260  ret = av_realloc(NULL, len + 1);
261  if (!ret)
262  return NULL;
263 
264  memcpy(ret, s, len);
265  ret[len] = 0;
266  return ret;
267 }
268 
269 void *av_memdup(const void *p, size_t size)
270 {
271  void *ptr = NULL;
272  if (p) {
273  ptr = av_malloc(size);
274  if (ptr)
275  memcpy(ptr, p, size);
276  }
277  return ptr;
278 }
279 
280 int av_dynarray_add_nofree(void *tab_ptr, int *nb_ptr, void *elem)
281 {
282  void **tab;
283  memcpy(&tab, tab_ptr, sizeof(tab));
284 
285  FF_DYNARRAY_ADD(INT_MAX, sizeof(*tab), tab, *nb_ptr, {
286  tab[*nb_ptr] = elem;
287  memcpy(tab_ptr, &tab, sizeof(tab));
288  }, {
289  return AVERROR(ENOMEM);
290  });
291  return 0;
292 }
293 
294 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem)
295 {
296  void **tab;
297  memcpy(&tab, tab_ptr, sizeof(tab));
298 
299  FF_DYNARRAY_ADD(INT_MAX, sizeof(*tab), tab, *nb_ptr, {
300  tab[*nb_ptr] = elem;
301  memcpy(tab_ptr, &tab, sizeof(tab));
302  }, {
303  *nb_ptr = 0;
304  av_freep(tab_ptr);
305  });
306 }
307 
308 void *av_dynarray2_add(void **tab_ptr, int *nb_ptr, size_t elem_size,
309  const uint8_t *elem_data)
310 {
311  uint8_t *tab_elem_data = NULL;
312 
313  FF_DYNARRAY_ADD(INT_MAX, elem_size, *tab_ptr, *nb_ptr, {
314  tab_elem_data = (uint8_t *)*tab_ptr + (*nb_ptr) * elem_size;
315  if (elem_data)
316  memcpy(tab_elem_data, elem_data, elem_size);
317  else if (CONFIG_MEMORY_POISONING)
318  memset(tab_elem_data, FF_MEMORY_POISON, elem_size);
319  }, {
320  av_freep(tab_ptr);
321  *nb_ptr = 0;
322  });
323  return tab_elem_data;
324 }
325 
326 static void fill16(uint8_t *dst, int len)
327 {
328  uint32_t v = AV_RN16(dst - 2);
329 
330  v |= v << 16;
331 
332  while (len >= 4) {
333  AV_WN32(dst, v);
334  dst += 4;
335  len -= 4;
336  }
337 
338  while (len--) {
339  *dst = dst[-2];
340  dst++;
341  }
342 }
343 
344 static void fill24(uint8_t *dst, int len)
345 {
346 #if HAVE_BIGENDIAN
347  uint32_t v = AV_RB24(dst - 3);
348  uint32_t a = v << 8 | v >> 16;
349  uint32_t b = v << 16 | v >> 8;
350  uint32_t c = v << 24 | v;
351 #else
352  uint32_t v = AV_RL24(dst - 3);
353  uint32_t a = v | v << 24;
354  uint32_t b = v >> 8 | v << 16;
355  uint32_t c = v >> 16 | v << 8;
356 #endif
357 
358  while (len >= 12) {
359  AV_WN32(dst, a);
360  AV_WN32(dst + 4, b);
361  AV_WN32(dst + 8, c);
362  dst += 12;
363  len -= 12;
364  }
365 
366  if (len >= 4) {
367  AV_WN32(dst, a);
368  dst += 4;
369  len -= 4;
370  }
371 
372  if (len >= 4) {
373  AV_WN32(dst, b);
374  dst += 4;
375  len -= 4;
376  }
377 
378  while (len--) {
379  *dst = dst[-3];
380  dst++;
381  }
382 }
383 
384 static void fill32(uint8_t *dst, int len)
385 {
386  uint32_t v = AV_RN32(dst - 4);
387 
388  while (len >= 4) {
389  AV_WN32(dst, v);
390  dst += 4;
391  len -= 4;
392  }
393 
394  while (len--) {
395  *dst = dst[-4];
396  dst++;
397  }
398 }
399 
400 void av_memcpy_backptr(uint8_t *dst, int back, int cnt)
401 {
402  const uint8_t *src = &dst[-back];
403  if (!back)
404  return;
405 
406  if (back == 1) {
407  memset(dst, *src, cnt);
408  } else if (back == 2) {
409  fill16(dst, cnt);
410  } else if (back == 3) {
411  fill24(dst, cnt);
412  } else if (back == 4) {
413  fill32(dst, cnt);
414  } else {
415  if (cnt >= 16) {
416  int blocklen = back;
417  while (cnt > blocklen) {
418  memcpy(dst, src, blocklen);
419  dst += blocklen;
420  cnt -= blocklen;
421  blocklen <<= 1;
422  }
423  memcpy(dst, src, cnt);
424  return;
425  }
426  if (cnt >= 8) {
427  AV_COPY32U(dst, src);
428  AV_COPY32U(dst + 4, src + 4);
429  src += 8;
430  dst += 8;
431  cnt -= 8;
432  }
433  if (cnt >= 4) {
434  AV_COPY32U(dst, src);
435  src += 4;
436  dst += 4;
437  cnt -= 4;
438  }
439  if (cnt >= 2) {
440  AV_COPY16U(dst, src);
441  src += 2;
442  dst += 2;
443  cnt -= 2;
444  }
445  if (cnt)
446  *dst = *src;
447  }
448 }
449 
450 void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size)
451 {
452  if (min_size < *size)
453  return ptr;
454 
455  min_size = FFMAX(min_size + min_size / 16 + 32, min_size);
456 
457  ptr = av_realloc(ptr, min_size);
458  /* we could set this to the unmodified min_size but this is safer
459  * if the user lost the ptr and uses NULL now
460  */
461  if (!ptr)
462  min_size = 0;
463 
464  *size = min_size;
465 
466  return ptr;
467 }
468 
469 void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size)
470 {
471  ff_fast_malloc(ptr, size, min_size, 0);
472 }
473 
474 void av_fast_mallocz(void *ptr, unsigned int *size, size_t min_size)
475 {
476  ff_fast_malloc(ptr, size, min_size, 1);
477 }
#define NULL
Definition: coverity.c:32
void * av_realloc_f(void *ptr, size_t nelem, size_t elsize)
Allocate, reallocate, or free a block of memory.
Definition: mem.c:148
const char const char void * val
Definition: avisynth_c.h:771
const char * s
Definition: avisynth_c.h:768
void av_max_alloc(size_t max)
Set the maximum size that may be allocated in one block.
Definition: mem.c:73
void * av_realloc(void *ptr, size_t size)
Allocate, reallocate, or free a block of memory.
Definition: mem.c:135
Memory handling functions.
#define FF_MEMORY_POISON
Definition: internal.h:89
const char * b
Definition: vf_curves.c:113
Convenience header that includes libavutil's core.
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:222
#define src
Definition: vp8dsp.c:254
static void fill16(uint8_t *dst, int len)
Definition: mem.c:326
void * av_calloc(size_t nmemb, size_t size)
Non-inlined equivalent of av_mallocz_array().
Definition: mem.c:230
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
static void fill32(uint8_t *dst, int len)
Definition: mem.c:384
void av_memcpy_backptr(uint8_t *dst, int back, int cnt)
Overlapping memcpy() implementation.
Definition: mem.c:400
int av_dynarray_add_nofree(void *tab_ptr, int *nb_ptr, void *elem)
Add an element to a dynamic array.
Definition: mem.c:280
ptrdiff_t size
Definition: opengl_enc.c:101
void * av_realloc_array(void *ptr, size_t nmemb, size_t size)
Definition: mem.c:184
#define AV_COPY16U(d, s)
Definition: intreadwrite.h:558
#define AVERROR(e)
Definition: error.h:43
void av_freep(void *arg)
Free a memory block which has been allocated with a function of av_malloc() or av_realloc() family...
Definition: mem.c:213
const char * r
Definition: vf_curves.c:111
const char * arg
Definition: jacosubdec.c:66
simple assert() macros that are a bit more flexible than ISO C assert().
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_RL24
Definition: bytestream.h:87
void * av_memdup(const void *p, size_t size)
Duplicate a buffer with av_malloc().
Definition: mem.c:269
#define FFMAX(a, b)
Definition: common.h:94
int av_reallocp_array(void *ptr, size_t nmemb, size_t size)
Definition: mem.c:191
void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size)
Allocate a buffer, reusing the given one if large enough.
Definition: mem.c:469
void av_fast_mallocz(void *ptr, unsigned int *size, size_t min_size)
Allocate and clear a buffer, reusing the given one if large enough.
Definition: mem.c:474
#define AV_COPY32U(d, s)
Definition: intreadwrite.h:562
void * av_fast_realloc(void *ptr, unsigned int *size, size_t min_size)
Reallocate the given buffer if it is not large enough, otherwise do nothing.
Definition: mem.c:450
const AVS_VideoInfo int align
Definition: avisynth_c.h:795
int av_reallocp(void *ptr, size_t size)
Allocate, reallocate, or free a block of memory through a pointer to a pointer.
Definition: mem.c:163
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:237
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:87
void * av_dynarray2_add(void **tab_ptr, int *nb_ptr, size_t elem_size, const uint8_t *elem_data)
Add an element of size elem_size to a dynamic array.
Definition: mem.c:308
#define AV_RN16(p)
Definition: intreadwrite.h:365
#define ALIGN
Definition: mem.c:64
static size_t max_alloc_size
Definition: mem.c:71
#define AV_RN32(p)
Definition: intreadwrite.h:369
void av_free(void *ptr)
Free a memory block which has been allocated with a function of av_malloc() or av_realloc() family...
Definition: mem.c:204
static void fill24(uint8_t *dst, int len)
Definition: mem.c:344
void * av_malloc(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:77
#define FF_DYNARRAY_ADD(av_size_max, av_elt_size, av_array, av_size, av_success, av_failure)
Add an element of to a dynamic array.
Definition: dynarray.h:45
common internal and external API header
#define AV_WN32(p, v)
Definition: intreadwrite.h:381
static double c[64]
static int av_size_mult(size_t a, size_t b, size_t *r)
Multiply two size_t values checking for overflow.
Definition: mem.h:665
void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem)
Add the pointer to an element to a dynamic array.
Definition: mem.c:294
int len
static const struct twinvq_data tab
static int ff_fast_malloc(void *ptr, unsigned int *size, size_t min_size, int zero_realloc)
Definition: mem_internal.h:27
char * av_strndup(const char *s, size_t len)
Duplicate a substring of a string.
Definition: mem.c:249