Commit | Line | Data |
---|---|---|
2ba45a60 DM |
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 <stdint.h> | |
20 | #include <string.h> | |
21 | ||
22 | #include "atomic.h" | |
23 | #include "buffer_internal.h" | |
24 | #include "common.h" | |
25 | #include "mem.h" | |
f6fa7814 | 26 | #include "thread.h" |
2ba45a60 DM |
27 | |
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 | buf->refcount = 1; | |
44 | ||
45 | if (flags & AV_BUFFER_FLAG_READONLY) | |
46 | buf->flags |= BUFFER_FLAG_READONLY; | |
47 | ||
48 | ref = av_mallocz(sizeof(*ref)); | |
49 | if (!ref) { | |
50 | av_freep(&buf); | |
51 | return NULL; | |
52 | } | |
53 | ||
54 | ref->buffer = buf; | |
55 | ref->data = data; | |
56 | ref->size = size; | |
57 | ||
58 | return ref; | |
59 | } | |
60 | ||
61 | void av_buffer_default_free(void *opaque, uint8_t *data) | |
62 | { | |
63 | av_free(data); | |
64 | } | |
65 | ||
66 | AVBufferRef *av_buffer_alloc(int size) | |
67 | { | |
68 | AVBufferRef *ret = NULL; | |
69 | uint8_t *data = NULL; | |
70 | ||
71 | data = av_malloc(size); | |
72 | if (!data) | |
73 | return NULL; | |
74 | ||
75 | ret = av_buffer_create(data, size, av_buffer_default_free, NULL, 0); | |
76 | if (!ret) | |
77 | av_freep(&data); | |
78 | ||
79 | return ret; | |
80 | } | |
81 | ||
82 | AVBufferRef *av_buffer_allocz(int size) | |
83 | { | |
84 | AVBufferRef *ret = av_buffer_alloc(size); | |
85 | if (!ret) | |
86 | return NULL; | |
87 | ||
88 | memset(ret->data, 0, size); | |
89 | return ret; | |
90 | } | |
91 | ||
92 | AVBufferRef *av_buffer_ref(AVBufferRef *buf) | |
93 | { | |
94 | AVBufferRef *ret = av_mallocz(sizeof(*ret)); | |
95 | ||
96 | if (!ret) | |
97 | return NULL; | |
98 | ||
99 | *ret = *buf; | |
100 | ||
101 | avpriv_atomic_int_add_and_fetch(&buf->buffer->refcount, 1); | |
102 | ||
103 | return ret; | |
104 | } | |
105 | ||
106 | void av_buffer_unref(AVBufferRef **buf) | |
107 | { | |
108 | AVBuffer *b; | |
109 | ||
110 | if (!buf || !*buf) | |
111 | return; | |
112 | b = (*buf)->buffer; | |
113 | av_freep(buf); | |
114 | ||
115 | if (!avpriv_atomic_int_add_and_fetch(&b->refcount, -1)) { | |
116 | b->free(b->opaque, b->data); | |
117 | av_freep(&b); | |
118 | } | |
119 | } | |
120 | ||
121 | int av_buffer_is_writable(const AVBufferRef *buf) | |
122 | { | |
123 | if (buf->buffer->flags & AV_BUFFER_FLAG_READONLY) | |
124 | return 0; | |
125 | ||
126 | return avpriv_atomic_int_get(&buf->buffer->refcount) == 1; | |
127 | } | |
128 | ||
129 | void *av_buffer_get_opaque(const AVBufferRef *buf) | |
130 | { | |
131 | return buf->buffer->opaque; | |
132 | } | |
133 | ||
134 | int av_buffer_get_ref_count(const AVBufferRef *buf) | |
135 | { | |
136 | return buf->buffer->refcount; | |
137 | } | |
138 | ||
139 | int av_buffer_make_writable(AVBufferRef **pbuf) | |
140 | { | |
141 | AVBufferRef *newbuf, *buf = *pbuf; | |
142 | ||
143 | if (av_buffer_is_writable(buf)) | |
144 | return 0; | |
145 | ||
146 | newbuf = av_buffer_alloc(buf->size); | |
147 | if (!newbuf) | |
148 | return AVERROR(ENOMEM); | |
149 | ||
150 | memcpy(newbuf->data, buf->data, buf->size); | |
151 | av_buffer_unref(pbuf); | |
152 | *pbuf = newbuf; | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
157 | int av_buffer_realloc(AVBufferRef **pbuf, int size) | |
158 | { | |
159 | AVBufferRef *buf = *pbuf; | |
160 | uint8_t *tmp; | |
161 | ||
162 | if (!buf) { | |
163 | /* allocate a new buffer with av_realloc(), so it will be reallocatable | |
164 | * later */ | |
165 | uint8_t *data = av_realloc(NULL, size); | |
166 | if (!data) | |
167 | return AVERROR(ENOMEM); | |
168 | ||
169 | buf = av_buffer_create(data, size, av_buffer_default_free, NULL, 0); | |
170 | if (!buf) { | |
171 | av_freep(&data); | |
172 | return AVERROR(ENOMEM); | |
173 | } | |
174 | ||
175 | buf->buffer->flags |= BUFFER_FLAG_REALLOCATABLE; | |
176 | *pbuf = buf; | |
177 | ||
178 | return 0; | |
179 | } else if (buf->size == size) | |
180 | return 0; | |
181 | ||
182 | if (!(buf->buffer->flags & BUFFER_FLAG_REALLOCATABLE) || | |
183 | !av_buffer_is_writable(buf)) { | |
184 | /* cannot realloc, allocate a new reallocable buffer and copy data */ | |
185 | AVBufferRef *new = NULL; | |
186 | ||
187 | av_buffer_realloc(&new, size); | |
188 | if (!new) | |
189 | return AVERROR(ENOMEM); | |
190 | ||
191 | memcpy(new->data, buf->data, FFMIN(size, buf->size)); | |
192 | ||
193 | av_buffer_unref(pbuf); | |
194 | *pbuf = new; | |
195 | return 0; | |
196 | } | |
197 | ||
198 | tmp = av_realloc(buf->buffer->data, size); | |
199 | if (!tmp) | |
200 | return AVERROR(ENOMEM); | |
201 | ||
202 | buf->buffer->data = buf->data = tmp; | |
203 | buf->buffer->size = buf->size = size; | |
204 | return 0; | |
205 | } | |
206 | ||
207 | AVBufferPool *av_buffer_pool_init(int size, AVBufferRef* (*alloc)(int size)) | |
208 | { | |
209 | AVBufferPool *pool = av_mallocz(sizeof(*pool)); | |
210 | if (!pool) | |
211 | return NULL; | |
212 | ||
f6fa7814 DM |
213 | ff_mutex_init(&pool->mutex, NULL); |
214 | ||
2ba45a60 DM |
215 | pool->size = size; |
216 | pool->alloc = alloc ? alloc : av_buffer_alloc; | |
217 | ||
218 | avpriv_atomic_int_set(&pool->refcount, 1); | |
219 | ||
220 | return pool; | |
221 | } | |
222 | ||
223 | /* | |
224 | * This function gets called when the pool has been uninited and | |
225 | * all the buffers returned to it. | |
226 | */ | |
227 | static void buffer_pool_free(AVBufferPool *pool) | |
228 | { | |
229 | while (pool->pool) { | |
230 | BufferPoolEntry *buf = pool->pool; | |
231 | pool->pool = buf->next; | |
232 | ||
233 | buf->free(buf->opaque, buf->data); | |
234 | av_freep(&buf); | |
235 | } | |
f6fa7814 | 236 | ff_mutex_destroy(&pool->mutex); |
2ba45a60 DM |
237 | av_freep(&pool); |
238 | } | |
239 | ||
240 | void av_buffer_pool_uninit(AVBufferPool **ppool) | |
241 | { | |
242 | AVBufferPool *pool; | |
243 | ||
244 | if (!ppool || !*ppool) | |
245 | return; | |
246 | pool = *ppool; | |
247 | *ppool = NULL; | |
248 | ||
249 | if (!avpriv_atomic_int_add_and_fetch(&pool->refcount, -1)) | |
250 | buffer_pool_free(pool); | |
251 | } | |
252 | ||
253 | /* remove the whole buffer list from the pool and return it */ | |
254 | static BufferPoolEntry *get_pool(AVBufferPool *pool) | |
255 | { | |
256 | BufferPoolEntry *cur = *(void * volatile *)&pool->pool, *last = NULL; | |
257 | ||
258 | while (cur != last) { | |
259 | last = cur; | |
260 | cur = avpriv_atomic_ptr_cas((void * volatile *)&pool->pool, last, NULL); | |
261 | if (!cur) | |
262 | return NULL; | |
263 | } | |
264 | ||
265 | return cur; | |
266 | } | |
267 | ||
268 | static void add_to_pool(BufferPoolEntry *buf) | |
269 | { | |
270 | AVBufferPool *pool; | |
271 | BufferPoolEntry *cur, *end = buf; | |
272 | ||
273 | if (!buf) | |
274 | return; | |
275 | pool = buf->pool; | |
276 | ||
277 | while (end->next) | |
278 | end = end->next; | |
279 | ||
280 | while (avpriv_atomic_ptr_cas((void * volatile *)&pool->pool, NULL, buf)) { | |
281 | /* pool is not empty, retrieve it and append it to our list */ | |
282 | cur = get_pool(pool); | |
283 | end->next = cur; | |
284 | while (end->next) | |
285 | end = end->next; | |
286 | } | |
287 | } | |
288 | ||
289 | static void pool_release_buffer(void *opaque, uint8_t *data) | |
290 | { | |
291 | BufferPoolEntry *buf = opaque; | |
292 | AVBufferPool *pool = buf->pool; | |
293 | ||
294 | if(CONFIG_MEMORY_POISONING) | |
295 | memset(buf->data, FF_MEMORY_POISON, pool->size); | |
296 | ||
f6fa7814 | 297 | #if USE_ATOMICS |
2ba45a60 | 298 | add_to_pool(buf); |
f6fa7814 DM |
299 | #else |
300 | ff_mutex_lock(&pool->mutex); | |
301 | buf->next = pool->pool; | |
302 | pool->pool = buf; | |
303 | ff_mutex_unlock(&pool->mutex); | |
304 | #endif | |
305 | ||
2ba45a60 DM |
306 | if (!avpriv_atomic_int_add_and_fetch(&pool->refcount, -1)) |
307 | buffer_pool_free(pool); | |
308 | } | |
309 | ||
310 | /* allocate a new buffer and override its free() callback so that | |
311 | * it is returned to the pool on free */ | |
312 | static AVBufferRef *pool_alloc_buffer(AVBufferPool *pool) | |
313 | { | |
314 | BufferPoolEntry *buf; | |
315 | AVBufferRef *ret; | |
316 | ||
317 | ret = pool->alloc(pool->size); | |
318 | if (!ret) | |
319 | return NULL; | |
320 | ||
321 | buf = av_mallocz(sizeof(*buf)); | |
322 | if (!buf) { | |
323 | av_buffer_unref(&ret); | |
324 | return NULL; | |
325 | } | |
326 | ||
327 | buf->data = ret->buffer->data; | |
328 | buf->opaque = ret->buffer->opaque; | |
329 | buf->free = ret->buffer->free; | |
330 | buf->pool = pool; | |
331 | ||
332 | ret->buffer->opaque = buf; | |
333 | ret->buffer->free = pool_release_buffer; | |
334 | ||
f6fa7814 | 335 | #if USE_ATOMICS |
2ba45a60 DM |
336 | avpriv_atomic_int_add_and_fetch(&pool->refcount, 1); |
337 | avpriv_atomic_int_add_and_fetch(&pool->nb_allocated, 1); | |
f6fa7814 | 338 | #endif |
2ba45a60 DM |
339 | |
340 | return ret; | |
341 | } | |
342 | ||
343 | AVBufferRef *av_buffer_pool_get(AVBufferPool *pool) | |
344 | { | |
345 | AVBufferRef *ret; | |
346 | BufferPoolEntry *buf; | |
347 | ||
f6fa7814 | 348 | #if USE_ATOMICS |
2ba45a60 DM |
349 | /* check whether the pool is empty */ |
350 | buf = get_pool(pool); | |
351 | if (!buf && pool->refcount <= pool->nb_allocated) { | |
352 | av_log(NULL, AV_LOG_DEBUG, "Pool race dectected, spining to avoid overallocation and eventual OOM\n"); | |
353 | while (!buf && avpriv_atomic_int_get(&pool->refcount) <= avpriv_atomic_int_get(&pool->nb_allocated)) | |
354 | buf = get_pool(pool); | |
355 | } | |
356 | ||
357 | if (!buf) | |
358 | return pool_alloc_buffer(pool); | |
359 | ||
360 | /* keep the first entry, return the rest of the list to the pool */ | |
361 | add_to_pool(buf->next); | |
362 | buf->next = NULL; | |
363 | ||
364 | ret = av_buffer_create(buf->data, pool->size, pool_release_buffer, | |
365 | buf, 0); | |
366 | if (!ret) { | |
367 | add_to_pool(buf); | |
368 | return NULL; | |
369 | } | |
f6fa7814 DM |
370 | #else |
371 | ff_mutex_lock(&pool->mutex); | |
372 | buf = pool->pool; | |
373 | if (buf) { | |
374 | ret = av_buffer_create(buf->data, pool->size, pool_release_buffer, | |
375 | buf, 0); | |
376 | if (ret) { | |
377 | pool->pool = buf->next; | |
378 | buf->next = NULL; | |
379 | } | |
380 | } else { | |
381 | ret = pool_alloc_buffer(pool); | |
382 | } | |
383 | ff_mutex_unlock(&pool->mutex); | |
384 | #endif | |
385 | ||
386 | if (ret) | |
387 | avpriv_atomic_int_add_and_fetch(&pool->refcount, 1); | |
2ba45a60 DM |
388 | |
389 | return ret; | |
390 | } |