1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include <stdatomic.h>
20 #include <stdint.h>
21 #include <string.h>
22
23 #include "avassert.h"
24 #include "buffer_internal.h"
25 #include "common.h"
26 #include "mem.h"
27 #include "thread.h"
28
av_buffer_create(uint8_t * data,buffer_size_t size,void (* free)(void * opaque,uint8_t * data),void * opaque,int flags)29 AVBufferRef *av_buffer_create(uint8_t *data, buffer_size_t size,
30 void (*free)(void *opaque, uint8_t *data),
31 void *opaque, int flags)
32 {
33 AVBufferRef *ref = NULL;
34 AVBuffer *buf = NULL;
35
36 buf = av_mallocz(sizeof(*buf));
37 if (!buf)
38 return NULL;
39
40 buf->data = data;
41 buf->size = size;
42 buf->free = free ? free : av_buffer_default_free;
43 buf->opaque = opaque;
44
45 atomic_init(&buf->refcount, 1);
46
47 buf->flags = flags;
48
49 ref = av_mallocz(sizeof(*ref));
50 if (!ref) {
51 av_freep(&buf);
52 return NULL;
53 }
54
55 ref->buffer = buf;
56 ref->data = data;
57 ref->size = size;
58
59 return ref;
60 }
61
av_buffer_default_free(void * opaque,uint8_t * data)62 void av_buffer_default_free(void *opaque, uint8_t *data)
63 {
64 av_free(data);
65 }
66
av_buffer_alloc(buffer_size_t size)67 AVBufferRef *av_buffer_alloc(buffer_size_t size)
68 {
69 AVBufferRef *ret = NULL;
70 uint8_t *data = NULL;
71
72 data = av_malloc(size);
73 if (!data)
74 return NULL;
75
76 ret = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);
77 if (!ret)
78 av_freep(&data);
79
80 return ret;
81 }
82
av_buffer_allocz(buffer_size_t size)83 AVBufferRef *av_buffer_allocz(buffer_size_t size)
84 {
85 AVBufferRef *ret = av_buffer_alloc(size);
86 if (!ret)
87 return NULL;
88
89 memset(ret->data, 0, size);
90 return ret;
91 }
92
av_buffer_ref(AVBufferRef * buf)93 AVBufferRef *av_buffer_ref(AVBufferRef *buf)
94 {
95 AVBufferRef *ret = av_mallocz(sizeof(*ret));
96
97 if (!ret)
98 return NULL;
99
100 *ret = *buf;
101
102 atomic_fetch_add_explicit(&buf->buffer->refcount, 1, memory_order_relaxed);
103
104 return ret;
105 }
106
buffer_replace(AVBufferRef ** dst,AVBufferRef ** src)107 static void buffer_replace(AVBufferRef **dst, AVBufferRef **src)
108 {
109 AVBuffer *b;
110
111 b = (*dst)->buffer;
112
113 if (src) {
114 **dst = **src;
115 av_freep(src);
116 } else
117 av_freep(dst);
118
119 if (atomic_fetch_sub_explicit(&b->refcount, 1, memory_order_acq_rel) == 1) {
120 b->free(b->opaque, b->data);
121 av_freep(&b);
122 }
123 }
124
av_buffer_unref(AVBufferRef ** buf)125 void av_buffer_unref(AVBufferRef **buf)
126 {
127 if (!buf || !*buf)
128 return;
129
130 buffer_replace(buf, NULL);
131 }
132
av_buffer_is_writable(const AVBufferRef * buf)133 int av_buffer_is_writable(const AVBufferRef *buf)
134 {
135 if (buf->buffer->flags & AV_BUFFER_FLAG_READONLY)
136 return 0;
137
138 return atomic_load(&buf->buffer->refcount) == 1;
139 }
140
av_buffer_get_opaque(const AVBufferRef * buf)141 void *av_buffer_get_opaque(const AVBufferRef *buf)
142 {
143 return buf->buffer->opaque;
144 }
145
av_buffer_get_ref_count(const AVBufferRef * buf)146 int av_buffer_get_ref_count(const AVBufferRef *buf)
147 {
148 return atomic_load(&buf->buffer->refcount);
149 }
150
av_buffer_make_writable(AVBufferRef ** pbuf)151 int av_buffer_make_writable(AVBufferRef **pbuf)
152 {
153 AVBufferRef *newbuf, *buf = *pbuf;
154
155 if (av_buffer_is_writable(buf))
156 return 0;
157
158 newbuf = av_buffer_alloc(buf->size);
159 if (!newbuf)
160 return AVERROR(ENOMEM);
161
162 memcpy(newbuf->data, buf->data, buf->size);
163
164 buffer_replace(pbuf, &newbuf);
165
166 return 0;
167 }
168
av_buffer_realloc(AVBufferRef ** pbuf,buffer_size_t size)169 int av_buffer_realloc(AVBufferRef **pbuf, buffer_size_t size)
170 {
171 AVBufferRef *buf = *pbuf;
172 uint8_t *tmp;
173 int ret;
174
175 if (!buf) {
176 /* allocate a new buffer with av_realloc(), so it will be reallocatable
177 * later */
178 uint8_t *data = av_realloc(NULL, size);
179 if (!data)
180 return AVERROR(ENOMEM);
181
182 buf = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);
183 if (!buf) {
184 av_freep(&data);
185 return AVERROR(ENOMEM);
186 }
187
188 buf->buffer->flags_internal |= BUFFER_FLAG_REALLOCATABLE;
189 *pbuf = buf;
190
191 return 0;
192 } else if (buf->size == size)
193 return 0;
194
195 if (!(buf->buffer->flags_internal & BUFFER_FLAG_REALLOCATABLE) ||
196 !av_buffer_is_writable(buf) || buf->data != buf->buffer->data) {
197 /* cannot realloc, allocate a new reallocable buffer and copy data */
198 AVBufferRef *new = NULL;
199
200 ret = av_buffer_realloc(&new, size);
201 if (ret < 0)
202 return ret;
203
204 memcpy(new->data, buf->data, FFMIN(size, buf->size));
205
206 buffer_replace(pbuf, &new);
207 return 0;
208 }
209
210 tmp = av_realloc(buf->buffer->data, size);
211 if (!tmp)
212 return AVERROR(ENOMEM);
213
214 buf->buffer->data = buf->data = tmp;
215 buf->buffer->size = buf->size = size;
216 return 0;
217 }
218
av_buffer_replace(AVBufferRef ** pdst,AVBufferRef * src)219 int av_buffer_replace(AVBufferRef **pdst, AVBufferRef *src)
220 {
221 AVBufferRef *dst = *pdst;
222 AVBufferRef *tmp;
223
224 if (!src) {
225 av_buffer_unref(pdst);
226 return 0;
227 }
228
229 if (dst && dst->buffer == src->buffer) {
230 /* make sure the data pointers match */
231 dst->data = src->data;
232 dst->size = src->size;
233 return 0;
234 }
235
236 tmp = av_buffer_ref(src);
237 if (!tmp)
238 return AVERROR(ENOMEM);
239
240 av_buffer_unref(pdst);
241 *pdst = tmp;
242 return 0;
243 }
244
av_buffer_pool_init2(buffer_size_t size,void * opaque,AVBufferRef * (* alloc)(void * opaque,buffer_size_t size),void (* pool_free)(void * opaque))245 AVBufferPool *av_buffer_pool_init2(buffer_size_t size, void *opaque,
246 AVBufferRef* (*alloc)(void *opaque, buffer_size_t size),
247 void (*pool_free)(void *opaque))
248 {
249 AVBufferPool *pool = av_mallocz(sizeof(*pool));
250 if (!pool)
251 return NULL;
252
253 ff_mutex_init(&pool->mutex, NULL);
254
255 pool->size = size;
256 pool->opaque = opaque;
257 pool->alloc2 = alloc;
258 pool->alloc = av_buffer_alloc; // fallback
259 pool->pool_free = pool_free;
260
261 atomic_init(&pool->refcount, 1);
262
263 return pool;
264 }
265
av_buffer_pool_init(buffer_size_t size,AVBufferRef * (* alloc)(buffer_size_t size))266 AVBufferPool *av_buffer_pool_init(buffer_size_t size, AVBufferRef* (*alloc)(buffer_size_t size))
267 {
268 AVBufferPool *pool = av_mallocz(sizeof(*pool));
269 if (!pool)
270 return NULL;
271
272 ff_mutex_init(&pool->mutex, NULL);
273
274 pool->size = size;
275 pool->alloc = alloc ? alloc : av_buffer_alloc;
276
277 atomic_init(&pool->refcount, 1);
278
279 return pool;
280 }
281
buffer_pool_flush(AVBufferPool * pool)282 static void buffer_pool_flush(AVBufferPool *pool)
283 {
284 while (pool->pool) {
285 BufferPoolEntry *buf = pool->pool;
286 pool->pool = buf->next;
287
288 buf->free(buf->opaque, buf->data);
289 av_freep(&buf);
290 }
291 }
292
293 /*
294 * This function gets called when the pool has been uninited and
295 * all the buffers returned to it.
296 */
buffer_pool_free(AVBufferPool * pool)297 static void buffer_pool_free(AVBufferPool *pool)
298 {
299 buffer_pool_flush(pool);
300 ff_mutex_destroy(&pool->mutex);
301
302 if (pool->pool_free)
303 pool->pool_free(pool->opaque);
304
305 av_freep(&pool);
306 }
307
av_buffer_pool_uninit(AVBufferPool ** ppool)308 void av_buffer_pool_uninit(AVBufferPool **ppool)
309 {
310 AVBufferPool *pool;
311
312 if (!ppool || !*ppool)
313 return;
314 pool = *ppool;
315 *ppool = NULL;
316
317 ff_mutex_lock(&pool->mutex);
318 buffer_pool_flush(pool);
319 ff_mutex_unlock(&pool->mutex);
320
321 if (atomic_fetch_sub_explicit(&pool->refcount, 1, memory_order_acq_rel) == 1)
322 buffer_pool_free(pool);
323 }
324
pool_release_buffer(void * opaque,uint8_t * data)325 static void pool_release_buffer(void *opaque, uint8_t *data)
326 {
327 BufferPoolEntry *buf = opaque;
328 AVBufferPool *pool = buf->pool;
329
330 if(CONFIG_MEMORY_POISONING)
331 memset(buf->data, FF_MEMORY_POISON, pool->size);
332
333 ff_mutex_lock(&pool->mutex);
334 buf->next = pool->pool;
335 pool->pool = buf;
336 ff_mutex_unlock(&pool->mutex);
337
338 if (atomic_fetch_sub_explicit(&pool->refcount, 1, memory_order_acq_rel) == 1)
339 buffer_pool_free(pool);
340 }
341
342 /* allocate a new buffer and override its free() callback so that
343 * it is returned to the pool on free */
pool_alloc_buffer(AVBufferPool * pool)344 static AVBufferRef *pool_alloc_buffer(AVBufferPool *pool)
345 {
346 BufferPoolEntry *buf;
347 AVBufferRef *ret;
348
349 av_assert0(pool->alloc || pool->alloc2);
350
351 ret = pool->alloc2 ? pool->alloc2(pool->opaque, pool->size) :
352 pool->alloc(pool->size);
353 if (!ret)
354 return NULL;
355
356 buf = av_mallocz(sizeof(*buf));
357 if (!buf) {
358 av_buffer_unref(&ret);
359 return NULL;
360 }
361
362 buf->data = ret->buffer->data;
363 buf->opaque = ret->buffer->opaque;
364 buf->free = ret->buffer->free;
365 buf->pool = pool;
366
367 ret->buffer->opaque = buf;
368 ret->buffer->free = pool_release_buffer;
369
370 return ret;
371 }
372
av_buffer_pool_get(AVBufferPool * pool)373 AVBufferRef *av_buffer_pool_get(AVBufferPool *pool)
374 {
375 AVBufferRef *ret;
376 BufferPoolEntry *buf;
377
378 ff_mutex_lock(&pool->mutex);
379 buf = pool->pool;
380 if (buf) {
381 ret = av_buffer_create(buf->data, pool->size, pool_release_buffer,
382 buf, 0);
383 if (ret) {
384 pool->pool = buf->next;
385 buf->next = NULL;
386 }
387 } else {
388 ret = pool_alloc_buffer(pool);
389 }
390 ff_mutex_unlock(&pool->mutex);
391
392 if (ret)
393 atomic_fetch_add_explicit(&pool->refcount, 1, memory_order_relaxed);
394
395 return ret;
396 }
397
av_buffer_pool_buffer_get_opaque(AVBufferRef * ref)398 void *av_buffer_pool_buffer_get_opaque(AVBufferRef *ref)
399 {
400 BufferPoolEntry *buf = ref->buffer->opaque;
401 av_assert0(buf);
402 return buf->opaque;
403 }
404