yading@11: /*
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include <stdint.h>
yading@11: #include <string.h>
yading@11: 
yading@11: #include "atomic.h"
yading@11: #include "buffer_internal.h"
yading@11: #include "common.h"
yading@11: #include "mem.h"
yading@11: 
yading@11: AVBufferRef *av_buffer_create(uint8_t *data, int size,
yading@11:                               void (*free)(void *opaque, uint8_t *data),
yading@11:                               void *opaque, int flags)
yading@11: {
yading@11:     AVBufferRef *ref = NULL;
yading@11:     AVBuffer    *buf = NULL;
yading@11: 
yading@11:     buf = av_mallocz(sizeof(*buf));
yading@11:     if (!buf)
yading@11:         return NULL;
yading@11: 
yading@11:     buf->data     = data;
yading@11:     buf->size     = size;
yading@11:     buf->free     = free ? free : av_buffer_default_free;
yading@11:     buf->opaque   = opaque;
yading@11:     buf->refcount = 1;
yading@11: 
yading@11:     if (flags & AV_BUFFER_FLAG_READONLY)
yading@11:         buf->flags |= BUFFER_FLAG_READONLY;
yading@11: 
yading@11:     ref = av_mallocz(sizeof(*ref));
yading@11:     if (!ref) {
yading@11:         av_freep(&buf);
yading@11:         return NULL;
yading@11:     }
yading@11: 
yading@11:     ref->buffer = buf;
yading@11:     ref->data   = data;
yading@11:     ref->size   = size;
yading@11: 
yading@11:     return ref;
yading@11: }
yading@11: 
yading@11: void av_buffer_default_free(void *opaque, uint8_t *data)
yading@11: {
yading@11:     av_free(data);
yading@11: }
yading@11: 
yading@11: AVBufferRef *av_buffer_alloc(int size)
yading@11: {
yading@11:     AVBufferRef *ret = NULL;
yading@11:     uint8_t    *data = NULL;
yading@11: 
yading@11:     data = av_malloc(size);
yading@11:     if (!data)
yading@11:         return NULL;
yading@11: 
yading@11:     ret = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);
yading@11:     if (!ret)
yading@11:         av_freep(&data);
yading@11: 
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: AVBufferRef *av_buffer_allocz(int size)
yading@11: {
yading@11:     AVBufferRef *ret = av_buffer_alloc(size);
yading@11:     if (!ret)
yading@11:         return NULL;
yading@11: 
yading@11:     memset(ret->data, 0, size);
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: AVBufferRef *av_buffer_ref(AVBufferRef *buf)
yading@11: {
yading@11:     AVBufferRef *ret = av_mallocz(sizeof(*ret));
yading@11: 
yading@11:     if (!ret)
yading@11:         return NULL;
yading@11: 
yading@11:     *ret = *buf;
yading@11: 
yading@11:     avpriv_atomic_int_add_and_fetch(&buf->buffer->refcount, 1);
yading@11: 
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: void av_buffer_unref(AVBufferRef **buf)
yading@11: {
yading@11:     AVBuffer *b;
yading@11: 
yading@11:     if (!buf || !*buf)
yading@11:         return;
yading@11:     b = (*buf)->buffer;
yading@11:     av_freep(buf);
yading@11: 
yading@11:     if (!avpriv_atomic_int_add_and_fetch(&b->refcount, -1)) {
yading@11:         b->free(b->opaque, b->data);
yading@11:         av_freep(&b);
yading@11:     }
yading@11: }
yading@11: 
yading@11: int av_buffer_is_writable(const AVBufferRef *buf)
yading@11: {
yading@11:     if (buf->buffer->flags & AV_BUFFER_FLAG_READONLY)
yading@11:         return 0;
yading@11: 
yading@11:     return avpriv_atomic_int_get(&buf->buffer->refcount) == 1;
yading@11: }
yading@11: 
yading@11: void *av_buffer_get_opaque(const AVBufferRef *buf)
yading@11: {
yading@11:     return buf->buffer->opaque;
yading@11: }
yading@11: 
yading@11: int av_buffer_get_ref_count(const AVBufferRef *buf)
yading@11: {
yading@11:     return buf->buffer->refcount;
yading@11: }
yading@11: 
yading@11: int av_buffer_make_writable(AVBufferRef **pbuf)
yading@11: {
yading@11:     AVBufferRef *newbuf, *buf = *pbuf;
yading@11: 
yading@11:     if (av_buffer_is_writable(buf))
yading@11:         return 0;
yading@11: 
yading@11:     newbuf = av_buffer_alloc(buf->size);
yading@11:     if (!newbuf)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     memcpy(newbuf->data, buf->data, buf->size);
yading@11:     av_buffer_unref(pbuf);
yading@11:     *pbuf = newbuf;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: int av_buffer_realloc(AVBufferRef **pbuf, int size)
yading@11: {
yading@11:     AVBufferRef *buf = *pbuf;
yading@11:     uint8_t *tmp;
yading@11: 
yading@11:     if (!buf) {
yading@11:         /* allocate a new buffer with av_realloc(), so it will be reallocatable
yading@11:          * later */
yading@11:         uint8_t *data = av_realloc(NULL, size);
yading@11:         if (!data)
yading@11:             return AVERROR(ENOMEM);
yading@11: 
yading@11:         buf = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);
yading@11:         if (!buf) {
yading@11:             av_freep(&data);
yading@11:             return AVERROR(ENOMEM);
yading@11:         }
yading@11: 
yading@11:         buf->buffer->flags |= BUFFER_FLAG_REALLOCATABLE;
yading@11:         *pbuf = buf;
yading@11: 
yading@11:         return 0;
yading@11:     } else if (buf->size == size)
yading@11:         return 0;
yading@11: 
yading@11:     if (!(buf->buffer->flags & BUFFER_FLAG_REALLOCATABLE) ||
yading@11:         !av_buffer_is_writable(buf)) {
yading@11:         /* cannot realloc, allocate a new reallocable buffer and copy data */
yading@11:         AVBufferRef *new = NULL;
yading@11: 
yading@11:         av_buffer_realloc(&new, size);
yading@11:         if (!new)
yading@11:             return AVERROR(ENOMEM);
yading@11: 
yading@11:         memcpy(new->data, buf->data, FFMIN(size, buf->size));
yading@11: 
yading@11:         av_buffer_unref(pbuf);
yading@11:         *pbuf = new;
yading@11:         return 0;
yading@11:     }
yading@11: 
yading@11:     tmp = av_realloc(buf->buffer->data, size);
yading@11:     if (!tmp)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     buf->buffer->data = buf->data = tmp;
yading@11:     buf->buffer->size = buf->size = size;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVBufferPool *av_buffer_pool_init(int size, AVBufferRef* (*alloc)(int size))
yading@11: {
yading@11:     AVBufferPool *pool = av_mallocz(sizeof(*pool));
yading@11:     if (!pool)
yading@11:         return NULL;
yading@11: 
yading@11:     pool->size     = size;
yading@11:     pool->alloc    = alloc ? alloc : av_buffer_alloc;
yading@11: 
yading@11:     avpriv_atomic_int_set(&pool->refcount, 1);
yading@11: 
yading@11:     return pool;
yading@11: }
yading@11: 
yading@11: /*
yading@11:  * This function gets called when the pool has been uninited and
yading@11:  * all the buffers returned to it.
yading@11:  */
yading@11: static void buffer_pool_free(AVBufferPool *pool)
yading@11: {
yading@11:     while (pool->pool) {
yading@11:         BufferPoolEntry *buf = pool->pool;
yading@11:         pool->pool = buf->next;
yading@11: 
yading@11:         buf->free(buf->opaque, buf->data);
yading@11:         av_freep(&buf);
yading@11:     }
yading@11:     av_freep(&pool);
yading@11: }
yading@11: 
yading@11: void av_buffer_pool_uninit(AVBufferPool **ppool)
yading@11: {
yading@11:     AVBufferPool *pool;
yading@11: 
yading@11:     if (!ppool || !*ppool)
yading@11:         return;
yading@11:     pool   = *ppool;
yading@11:     *ppool = NULL;
yading@11: 
yading@11:     if (!avpriv_atomic_int_add_and_fetch(&pool->refcount, -1))
yading@11:         buffer_pool_free(pool);
yading@11: }
yading@11: 
yading@11: /* remove the whole buffer list from the pool and return it */
yading@11: static BufferPoolEntry *get_pool(AVBufferPool *pool)
yading@11: {
yading@11:     BufferPoolEntry *cur = *(void * volatile *)&pool->pool, *last = NULL;
yading@11: 
yading@11:     while (cur != last) {
yading@11:         last = cur;
yading@11:         cur = avpriv_atomic_ptr_cas((void * volatile *)&pool->pool, last, NULL);
yading@11:         if (!cur)
yading@11:             return NULL;
yading@11:     }
yading@11: 
yading@11:     return cur;
yading@11: }
yading@11: 
yading@11: static void add_to_pool(BufferPoolEntry *buf)
yading@11: {
yading@11:     AVBufferPool *pool;
yading@11:     BufferPoolEntry *cur, *end = buf;
yading@11: 
yading@11:     if (!buf)
yading@11:         return;
yading@11:     pool = buf->pool;
yading@11: 
yading@11:     while (end->next)
yading@11:         end = end->next;
yading@11: 
yading@11:     while (avpriv_atomic_ptr_cas((void * volatile *)&pool->pool, NULL, buf)) {
yading@11:         /* pool is not empty, retrieve it and append it to our list */
yading@11:         cur = get_pool(pool);
yading@11:         end->next = cur;
yading@11:         while (end->next)
yading@11:             end = end->next;
yading@11:     }
yading@11: }
yading@11: 
yading@11: static void pool_release_buffer(void *opaque, uint8_t *data)
yading@11: {
yading@11:     BufferPoolEntry *buf = opaque;
yading@11:     AVBufferPool *pool = buf->pool;
yading@11: 
yading@11:     if(CONFIG_MEMORY_POISONING)
yading@11:         memset(buf->data, 0x2a, pool->size);
yading@11: 
yading@11:     add_to_pool(buf);
yading@11:     if (!avpriv_atomic_int_add_and_fetch(&pool->refcount, -1))
yading@11:         buffer_pool_free(pool);
yading@11: }
yading@11: 
yading@11: /* allocate a new buffer and override its free() callback so that
yading@11:  * it is returned to the pool on free */
yading@11: static AVBufferRef *pool_alloc_buffer(AVBufferPool *pool)
yading@11: {
yading@11:     BufferPoolEntry *buf;
yading@11:     AVBufferRef     *ret;
yading@11: 
yading@11:     ret = pool->alloc(pool->size);
yading@11:     if (!ret)
yading@11:         return NULL;
yading@11: 
yading@11:     buf = av_mallocz(sizeof(*buf));
yading@11:     if (!buf) {
yading@11:         av_buffer_unref(&ret);
yading@11:         return NULL;
yading@11:     }
yading@11: 
yading@11:     buf->data   = ret->buffer->data;
yading@11:     buf->opaque = ret->buffer->opaque;
yading@11:     buf->free   = ret->buffer->free;
yading@11:     buf->pool   = pool;
yading@11: 
yading@11:     ret->buffer->opaque = buf;
yading@11:     ret->buffer->free   = pool_release_buffer;
yading@11: 
yading@11:     avpriv_atomic_int_add_and_fetch(&pool->refcount, 1);
yading@11:     avpriv_atomic_int_add_and_fetch(&pool->nb_allocated, 1);
yading@11: 
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: AVBufferRef *av_buffer_pool_get(AVBufferPool *pool)
yading@11: {
yading@11:     AVBufferRef *ret;
yading@11:     BufferPoolEntry *buf;
yading@11: 
yading@11:     /* check whether the pool is empty */
yading@11:     buf = get_pool(pool);
yading@11:     if (!buf && pool->refcount <= pool->nb_allocated) {
yading@11:         av_log(NULL, AV_LOG_DEBUG, "Pool race dectected, spining to avoid overallocation and eventual OOM\n");
yading@11:         while (!buf && avpriv_atomic_int_get(&pool->refcount) <= avpriv_atomic_int_get(&pool->nb_allocated))
yading@11:             buf = get_pool(pool);
yading@11:     }
yading@11: 
yading@11:     if (!buf)
yading@11:         return pool_alloc_buffer(pool);
yading@11: 
yading@11:     /* keep the first entry, return the rest of the list to the pool */
yading@11:     add_to_pool(buf->next);
yading@11:     buf->next = NULL;
yading@11: 
yading@11:     ret = av_buffer_create(buf->data, pool->size, pool_release_buffer,
yading@11:                            buf, 0);
yading@11:     if (!ret) {
yading@11:         add_to_pool(buf);
yading@11:         return NULL;
yading@11:     }
yading@11:     avpriv_atomic_int_add_and_fetch(&pool->refcount, 1);
yading@11: 
yading@11:     return ret;
yading@11: }