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 "buffer_internal.h"
24 #include "common.h"
25 #include "mem.h"
26 #include "thread.h"
27
av_buffer_create(uint8_t * data,int size,void (* free)(void * opaque,uint8_t * data),void * opaque,int flags)28 AVBufferRef *av_buffer_create(uint8_t *data, int size,
29 void (*free)(void *opaque, uint8_t *data),
30 void *opaque, int flags)
31 {
32 AVBufferRef *ref = NULL;
33 AVBuffer *buf = NULL;
34
35 buf = av_mallocz(sizeof(*buf));
36 if (!buf)
37 return NULL;
38
39 buf->data = data;
40 buf->size = size;
41 buf->free = free ? free : av_buffer_default_free;
42 buf->opaque = opaque;
43
44 atomic_init(&buf->refcount, 1);
45
46 if (flags & AV_BUFFER_FLAG_READONLY)
47 buf->flags |= BUFFER_FLAG_READONLY;
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(int size)67 AVBufferRef *av_buffer_alloc(int 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(int size)83 AVBufferRef *av_buffer_allocz(int 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_add_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,int size)169 int av_buffer_realloc(AVBufferRef **pbuf, int size)
170 {
171 AVBufferRef *buf = *pbuf;
172 uint8_t *tmp;
173
174 if (!buf) {
175 /* allocate a new buffer with av_realloc(), so it will be reallocatable
176 * later */
177 uint8_t *data = av_realloc(NULL, size);
178 if (!data)
179 return AVERROR(ENOMEM);
180
181 buf = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);
182 if (!buf) {
183 av_freep(&data);
184 return AVERROR(ENOMEM);
185 }
186
187 buf->buffer->flags |= BUFFER_FLAG_REALLOCATABLE;
188 *pbuf = buf;
189
190 return 0;
191 } else if (buf->size == size)
192 return 0;
193
194 if (!(buf->buffer->flags & BUFFER_FLAG_REALLOCATABLE) ||
195 !av_buffer_is_writable(buf) || buf->data != buf->buffer->data) {
196 /* cannot realloc, allocate a new reallocable buffer and copy data */
197 AVBufferRef *new = NULL;
198
199 av_buffer_realloc(&new, size);
200 if (!new)
201 return AVERROR(ENOMEM);
202
203 memcpy(new->data, buf->data, FFMIN(size, buf->size));
204
205 buffer_replace(pbuf, &new);
206 return 0;
207 }
208
209 tmp = av_realloc(buf->buffer->data, size);
210 if (!tmp)
211 return AVERROR(ENOMEM);
212
213 buf->buffer->data = buf->data = tmp;
214 buf->buffer->size = buf->size = size;
215 return 0;
216 }
217
av_buffer_pool_init2(int size,void * opaque,AVBufferRef * (* alloc)(void * opaque,int size),void (* pool_free)(void * opaque))218 AVBufferPool *av_buffer_pool_init2(int size, void *opaque,
219 AVBufferRef* (*alloc)(void *opaque, int size),
220 void (*pool_free)(void *opaque))
221 {
222 AVBufferPool *pool = av_mallocz(sizeof(*pool));
223 if (!pool)
224 return NULL;
225
226 ff_mutex_init(&pool->mutex, NULL);
227
228 pool->size = size;
229 pool->opaque = opaque;
230 pool->alloc2 = alloc;
231 pool->pool_free = pool_free;
232
233 atomic_init(&pool->refcount, 1);
234
235 return pool;
236 }
237
av_buffer_pool_init(int size,AVBufferRef * (* alloc)(int size))238 AVBufferPool *av_buffer_pool_init(int size, AVBufferRef* (*alloc)(int size))
239 {
240 AVBufferPool *pool = av_mallocz(sizeof(*pool));
241 if (!pool)
242 return NULL;
243
244 ff_mutex_init(&pool->mutex, NULL);
245
246 pool->size = size;
247 pool->alloc = alloc ? alloc : av_buffer_alloc;
248
249 atomic_init(&pool->refcount, 1);
250
251 return pool;
252 }
253
254 /*
255 * This function gets called when the pool has been uninited and
256 * all the buffers returned to it.
257 */
buffer_pool_free(AVBufferPool * pool)258 static void buffer_pool_free(AVBufferPool *pool)
259 {
260 while (pool->pool) {
261 BufferPoolEntry *buf = pool->pool;
262 pool->pool = buf->next;
263
264 buf->free(buf->opaque, buf->data);
265 av_freep(&buf);
266 }
267 ff_mutex_destroy(&pool->mutex);
268
269 if (pool->pool_free)
270 pool->pool_free(pool->opaque);
271
272 av_freep(&pool);
273 }
274
av_buffer_pool_uninit(AVBufferPool ** ppool)275 void av_buffer_pool_uninit(AVBufferPool **ppool)
276 {
277 AVBufferPool *pool;
278
279 if (!ppool || !*ppool)
280 return;
281 pool = *ppool;
282 *ppool = NULL;
283
284 if (atomic_fetch_add_explicit(&pool->refcount, -1, memory_order_acq_rel) == 1)
285 buffer_pool_free(pool);
286 }
287
pool_release_buffer(void * opaque,uint8_t * data)288 static void pool_release_buffer(void *opaque, uint8_t *data)
289 {
290 BufferPoolEntry *buf = opaque;
291 AVBufferPool *pool = buf->pool;
292
293 if(CONFIG_MEMORY_POISONING)
294 memset(buf->data, FF_MEMORY_POISON, pool->size);
295
296 ff_mutex_lock(&pool->mutex);
297 buf->next = pool->pool;
298 pool->pool = buf;
299 ff_mutex_unlock(&pool->mutex);
300
301 if (atomic_fetch_add_explicit(&pool->refcount, -1, memory_order_acq_rel) == 1)
302 buffer_pool_free(pool);
303 }
304
305 /* allocate a new buffer and override its free() callback so that
306 * it is returned to the pool on free */
pool_alloc_buffer(AVBufferPool * pool)307 static AVBufferRef *pool_alloc_buffer(AVBufferPool *pool)
308 {
309 BufferPoolEntry *buf;
310 AVBufferRef *ret;
311
312 ret = pool->alloc2 ? pool->alloc2(pool->opaque, pool->size) :
313 pool->alloc(pool->size);
314 if (!ret)
315 return NULL;
316
317 buf = av_mallocz(sizeof(*buf));
318 if (!buf) {
319 av_buffer_unref(&ret);
320 return NULL;
321 }
322
323 buf->data = ret->buffer->data;
324 buf->opaque = ret->buffer->opaque;
325 buf->free = ret->buffer->free;
326 buf->pool = pool;
327
328 ret->buffer->opaque = buf;
329 ret->buffer->free = pool_release_buffer;
330
331 return ret;
332 }
333
av_buffer_pool_get(AVBufferPool * pool)334 AVBufferRef *av_buffer_pool_get(AVBufferPool *pool)
335 {
336 AVBufferRef *ret;
337 BufferPoolEntry *buf;
338
339 ff_mutex_lock(&pool->mutex);
340 buf = pool->pool;
341 if (buf) {
342 ret = av_buffer_create(buf->data, pool->size, pool_release_buffer,
343 buf, 0);
344 if (ret) {
345 pool->pool = buf->next;
346 buf->next = NULL;
347 }
348 } else {
349 ret = pool_alloc_buffer(pool);
350 }
351 ff_mutex_unlock(&pool->mutex);
352
353 if (ret)
354 atomic_fetch_add_explicit(&pool->refcount, 1, memory_order_relaxed);
355
356 return ret;
357 }
358