FFmpeg/libavutil/threadmessage.c

223 lines
6.3 KiB
C

/*
* Copyright (c) 2014 Nicolas George
*
* 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 "fifo.h"
#include "threadmessage.h"
#include "thread.h"
struct AVThreadMessageQueue {
#if HAVE_THREADS
AVFifoBuffer *fifo;
pthread_mutex_t lock;
pthread_cond_t cond_recv;
pthread_cond_t cond_send;
int err_send;
int err_recv;
unsigned elsize;
void (*free_func)(void *msg);
#else
int dummy;
#endif
};
int av_thread_message_queue_alloc(AVThreadMessageQueue **mq,
unsigned nelem,
unsigned elsize)
{
#if HAVE_THREADS
AVThreadMessageQueue *rmq;
int ret = 0;
if (nelem > INT_MAX / elsize)
return AVERROR(EINVAL);
if (!(rmq = av_mallocz(sizeof(*rmq))))
return AVERROR(ENOMEM);
if ((ret = pthread_mutex_init(&rmq->lock, NULL))) {
av_free(rmq);
return AVERROR(ret);
}
if ((ret = pthread_cond_init(&rmq->cond_recv, NULL))) {
pthread_mutex_destroy(&rmq->lock);
av_free(rmq);
return AVERROR(ret);
}
if ((ret = pthread_cond_init(&rmq->cond_send, NULL))) {
pthread_cond_destroy(&rmq->cond_recv);
pthread_mutex_destroy(&rmq->lock);
av_free(rmq);
return AVERROR(ret);
}
if (!(rmq->fifo = av_fifo_alloc(elsize * nelem))) {
pthread_cond_destroy(&rmq->cond_send);
pthread_cond_destroy(&rmq->cond_recv);
pthread_mutex_destroy(&rmq->lock);
av_free(rmq);
return AVERROR(ret);
}
rmq->elsize = elsize;
*mq = rmq;
return 0;
#else
*mq = NULL;
return AVERROR(ENOSYS);
#endif /* HAVE_THREADS */
}
void av_thread_message_queue_set_free_func(AVThreadMessageQueue *mq,
void (*free_func)(void *msg))
{
#if HAVE_THREADS
mq->free_func = free_func;
#endif
}
void av_thread_message_queue_free(AVThreadMessageQueue **mq)
{
#if HAVE_THREADS
if (*mq) {
av_thread_message_flush(*mq);
av_fifo_freep(&(*mq)->fifo);
pthread_cond_destroy(&(*mq)->cond_send);
pthread_cond_destroy(&(*mq)->cond_recv);
pthread_mutex_destroy(&(*mq)->lock);
av_freep(mq);
}
#endif
}
#if HAVE_THREADS
static int av_thread_message_queue_send_locked(AVThreadMessageQueue *mq,
void *msg,
unsigned flags)
{
while (!mq->err_send && av_fifo_space(mq->fifo) < mq->elsize) {
if ((flags & AV_THREAD_MESSAGE_NONBLOCK))
return AVERROR(EAGAIN);
pthread_cond_wait(&mq->cond_send, &mq->lock);
}
if (mq->err_send)
return mq->err_send;
av_fifo_generic_write(mq->fifo, msg, mq->elsize, NULL);
/* one message is sent, signal one receiver */
pthread_cond_signal(&mq->cond_recv);
return 0;
}
static int av_thread_message_queue_recv_locked(AVThreadMessageQueue *mq,
void *msg,
unsigned flags)
{
while (!mq->err_recv && av_fifo_size(mq->fifo) < mq->elsize) {
if ((flags & AV_THREAD_MESSAGE_NONBLOCK))
return AVERROR(EAGAIN);
pthread_cond_wait(&mq->cond_recv, &mq->lock);
}
if (av_fifo_size(mq->fifo) < mq->elsize)
return mq->err_recv;
av_fifo_generic_read(mq->fifo, msg, mq->elsize, NULL);
/* one message space appeared, signal one sender */
pthread_cond_signal(&mq->cond_send);
return 0;
}
#endif /* HAVE_THREADS */
int av_thread_message_queue_send(AVThreadMessageQueue *mq,
void *msg,
unsigned flags)
{
#if HAVE_THREADS
int ret;
pthread_mutex_lock(&mq->lock);
ret = av_thread_message_queue_send_locked(mq, msg, flags);
pthread_mutex_unlock(&mq->lock);
return ret;
#else
return AVERROR(ENOSYS);
#endif /* HAVE_THREADS */
}
int av_thread_message_queue_recv(AVThreadMessageQueue *mq,
void *msg,
unsigned flags)
{
#if HAVE_THREADS
int ret;
pthread_mutex_lock(&mq->lock);
ret = av_thread_message_queue_recv_locked(mq, msg, flags);
pthread_mutex_unlock(&mq->lock);
return ret;
#else
return AVERROR(ENOSYS);
#endif /* HAVE_THREADS */
}
void av_thread_message_queue_set_err_send(AVThreadMessageQueue *mq,
int err)
{
#if HAVE_THREADS
pthread_mutex_lock(&mq->lock);
mq->err_send = err;
pthread_cond_broadcast(&mq->cond_send);
pthread_mutex_unlock(&mq->lock);
#endif /* HAVE_THREADS */
}
void av_thread_message_queue_set_err_recv(AVThreadMessageQueue *mq,
int err)
{
#if HAVE_THREADS
pthread_mutex_lock(&mq->lock);
mq->err_recv = err;
pthread_cond_broadcast(&mq->cond_recv);
pthread_mutex_unlock(&mq->lock);
#endif /* HAVE_THREADS */
}
#if HAVE_THREADS
static void free_func_wrap(void *arg, void *msg, int size)
{
AVThreadMessageQueue *mq = arg;
mq->free_func(msg);
}
#endif
void av_thread_message_flush(AVThreadMessageQueue *mq)
{
#if HAVE_THREADS
int used, off;
void *free_func = mq->free_func;
pthread_mutex_lock(&mq->lock);
used = av_fifo_size(mq->fifo);
if (free_func)
for (off = 0; off < used; off += mq->elsize)
av_fifo_generic_peek_at(mq->fifo, mq, off, mq->elsize, free_func_wrap);
av_fifo_drain(mq->fifo, used);
/* only the senders need to be notified since the queue is empty and there
* is nothing to read */
pthread_cond_broadcast(&mq->cond_send);
pthread_mutex_unlock(&mq->lock);
#endif /* HAVE_THREADS */
}