/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdint.h>
#include <string.h>
#include "atomic.h"
#include "buffer_internal.h"
#include "common.h"
#include "mem.h"
#include "thread.h"
AVBufferRef *av_buffer_create(uint8_t *data, int size,
void (*free)(void *opaque
, uint8_t *data
), void *opaque, int flags)
{
AVBufferRef *ref = NULL;
AVBuffer *buf = NULL;
buf = av_mallocz(sizeof(*buf));
if (!buf)
return NULL;
buf->data = data;
buf->size = size;
buf->opaque = opaque;
buf->refcount = 1;
if (flags & AV_BUFFER_FLAG_READONLY)
buf->flags |= BUFFER_FLAG_READONLY;
ref = av_mallocz(sizeof(*ref));
if (!ref) {
av_freep(&buf);
return NULL;
}
ref->buffer = buf;
ref->data = data;
ref->size = size;
return ref;
}
void av_buffer_default_free(void *opaque, uint8_t *data)
{
av_free(data);
}
AVBufferRef *av_buffer_alloc(int size)
{
AVBufferRef *ret = NULL;
uint8_t *data = NULL;
data = av_malloc(size);
if (!data)
return NULL;
ret = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);
if (!ret)
av_freep(&data);
return ret;
}
AVBufferRef *av_buffer_allocz(int size)
{
AVBufferRef *ret = av_buffer_alloc(size);
if (!ret)
return NULL;
return ret;
}
AVBufferRef *av_buffer_ref(AVBufferRef *buf)
{
AVBufferRef *ret = av_mallocz(sizeof(*ret));
if (!ret)
return NULL;
*ret = *buf;
avpriv_atomic_int_add_and_fetch(&buf->buffer->refcount, 1);
return ret;
}
static void buffer_replace(AVBufferRef **dst, AVBufferRef **src)
{
AVBuffer *b;
b = (*dst)->buffer;
if (src) {
**dst = **src;
av_freep(src);
} else
av_freep(dst);
if (!avpriv_atomic_int_add_and_fetch(&b->refcount, -1)) {
b
->free(b
->opaque
, b
->data
); av_freep(&b);
}
}
void av_buffer_unref(AVBufferRef **buf)
{
if (!buf || !*buf)
return;
buffer_replace(buf, NULL);
}
int av_buffer_is_writable(const AVBufferRef *buf)
{
if (buf->buffer->flags & AV_BUFFER_FLAG_READONLY)
return 0;
return avpriv_atomic_int_get(&buf->buffer->refcount) == 1;
}
void *av_buffer_get_opaque(const AVBufferRef *buf)
{
return buf->buffer->opaque;
}
int av_buffer_get_ref_count(const AVBufferRef *buf)
{
return buf->buffer->refcount;
}
int av_buffer_make_writable(AVBufferRef **pbuf)
{
AVBufferRef *newbuf, *buf = *pbuf;
if (av_buffer_is_writable(buf))
return 0;
newbuf = av_buffer_alloc(buf->size);
if (!newbuf)
return AVERROR(ENOMEM);
memcpy(newbuf
->data
, buf
->data
, buf
->size
);
buffer_replace(pbuf, &newbuf);
return 0;
}
int av_buffer_realloc(AVBufferRef **pbuf, int size)
{
AVBufferRef *buf = *pbuf;
uint8_t *tmp;
if (!buf) {
/* allocate a new buffer with av_realloc(), so it will be reallocatable
* later */
uint8_t *data = av_realloc(NULL, size);
if (!data)
return AVERROR(ENOMEM);
buf = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);
if (!buf) {
av_freep(&data);
return AVERROR(ENOMEM);
}
buf->buffer->flags |= BUFFER_FLAG_REALLOCATABLE;
*pbuf = buf;
return 0;
} else if (buf->size == size)
return 0;
if (!(buf->buffer->flags & BUFFER_FLAG_REALLOCATABLE) ||
!av_buffer_is_writable(buf)) {
/* cannot realloc, allocate a new reallocable buffer and copy data */
AVBufferRef *new = NULL;
av_buffer_realloc(&new, size);
if (!new)
return AVERROR(ENOMEM);
memcpy(new
->data
, buf
->data
, FFMIN
(size
, buf
->size
));
buffer_replace(pbuf, &new);
return 0;
}
tmp = av_realloc(buf->buffer->data, size);
if (!tmp)
return AVERROR(ENOMEM);
buf->buffer->data = buf->data = tmp;
buf->buffer->size = buf->size = size;
return 0;
}
AVBufferPool *av_buffer_pool_init(int size, AVBufferRef* (*alloc)(int size))
{
AVBufferPool *pool = av_mallocz(sizeof(*pool));
if (!pool)
return NULL;
ff_mutex_init(&pool->mutex, NULL);
pool->size = size;
pool->alloc = alloc ? alloc : av_buffer_alloc;
avpriv_atomic_int_set(&pool->refcount, 1);
return pool;
}
/*
* This function gets called when the pool has been uninited and
* all the buffers returned to it.
*/
static void buffer_pool_free(AVBufferPool *pool)
{
while (pool->pool) {
BufferPoolEntry *buf = pool->pool;
pool->pool = buf->next;
buf
->free(buf
->opaque
, buf
->data
); av_freep(&buf);
}
ff_mutex_destroy(&pool->mutex);
av_freep(&pool);
}
void av_buffer_pool_uninit(AVBufferPool **ppool)
{
AVBufferPool *pool;
if (!ppool || !*ppool)
return;
pool = *ppool;
*ppool = NULL;
if (!avpriv_atomic_int_add_and_fetch(&pool->refcount, -1))
buffer_pool_free(pool);
}
#if USE_ATOMICS
/* remove the whole buffer list from the pool and return it */
static BufferPoolEntry *get_pool(AVBufferPool *pool)
{
BufferPoolEntry *cur = *(void * volatile *)&pool->pool, *last = NULL;
while (cur != last) {
last = cur;
cur = avpriv_atomic_ptr_cas((void * volatile *)&pool->pool, last, NULL);
if (!cur)
return NULL;
}
return cur;
}
static void add_to_pool(BufferPoolEntry *buf)
{
AVBufferPool *pool;
BufferPoolEntry *cur, *end = buf;
if (!buf)
return;
pool = buf->pool;
while (end->next)
end = end->next;
while (avpriv_atomic_ptr_cas((void * volatile *)&pool->pool, NULL, buf)) {
/* pool is not empty, retrieve it and append it to our list */
cur = get_pool(pool);
end->next = cur;
while (end->next)
end = end->next;
}
}
#endif
static void pool_release_buffer(void *opaque, uint8_t *data)
{
BufferPoolEntry *buf = opaque;
AVBufferPool *pool = buf->pool;
if(CONFIG_MEMORY_POISONING)
memset(buf
->data
, FF_MEMORY_POISON
, pool
->size
);
#if USE_ATOMICS
add_to_pool(buf);
#else
ff_mutex_lock(&pool->mutex);
buf->next = pool->pool;
pool->pool = buf;
ff_mutex_unlock(&pool->mutex);
#endif
if (!avpriv_atomic_int_add_and_fetch(&pool->refcount, -1))
buffer_pool_free(pool);
}
/* allocate a new buffer and override its free() callback so that
* it is returned to the pool on free */
static AVBufferRef *pool_alloc_buffer(AVBufferPool *pool)
{
BufferPoolEntry *buf;
AVBufferRef *ret;
ret = pool->alloc(pool->size);
if (!ret)
return NULL;
buf = av_mallocz(sizeof(*buf));
if (!buf) {
av_buffer_unref(&ret);
return NULL;
}
buf->data = ret->buffer->data;
buf->opaque = ret->buffer->opaque;
buf->pool = pool;
ret->buffer->opaque = buf;
ret
->buffer
->free = pool_release_buffer
;
#if USE_ATOMICS
avpriv_atomic_int_add_and_fetch(&pool->refcount, 1);
avpriv_atomic_int_add_and_fetch(&pool->nb_allocated, 1);
#endif
return ret;
}
AVBufferRef *av_buffer_pool_get(AVBufferPool *pool)
{
AVBufferRef *ret;
BufferPoolEntry *buf;
#if USE_ATOMICS
/* check whether the pool is empty */
buf = get_pool(pool);
if (!buf && pool->refcount <= pool->nb_allocated) {
av_log(NULL, AV_LOG_DEBUG, "Pool race dectected, spining to avoid overallocation and eventual OOM\n");
while (!buf && avpriv_atomic_int_get(&pool->refcount) <= avpriv_atomic_int_get(&pool->nb_allocated))
buf = get_pool(pool);
}
if (!buf)
return pool_alloc_buffer(pool);
/* keep the first entry, return the rest of the list to the pool */
add_to_pool(buf->next);
buf->next = NULL;
ret = av_buffer_create(buf->data, pool->size, pool_release_buffer,
buf, 0);
if (!ret) {
add_to_pool(buf);
return NULL;
}
#else
ff_mutex_lock(&pool->mutex);
buf = pool->pool;
if (buf) {
ret = av_buffer_create(buf->data, pool->size, pool_release_buffer,
buf, 0);
if (ret) {
pool->pool = buf->next;
buf->next = NULL;
}
} else {
ret = pool_alloc_buffer(pool);
}
ff_mutex_unlock(&pool->mutex);
#endif
if (ret)
avpriv_atomic_int_add_and_fetch(&pool->refcount, 1);
return ret;
}