[FFmpeg-devel] [PATCH 31/35] lavu/threadmessage: switch to new FIFO API

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Thu Jan 13 21:03:36 EET 2022


Anton Khirnov:
> ---
>  libavutil/threadmessage.c | 34 +++++++++++++++++-----------------
>  1 file changed, 17 insertions(+), 17 deletions(-)
> 
> diff --git a/libavutil/threadmessage.c b/libavutil/threadmessage.c
> index 764b7fb813..39d3525a78 100644
> --- a/libavutil/threadmessage.c
> +++ b/libavutil/threadmessage.c
> @@ -64,7 +64,7 @@ int av_thread_message_queue_alloc(AVThreadMessageQueue **mq,
>          av_free(rmq);
>          return AVERROR(ret);
>      }
> -    if (!(rmq->fifo = av_fifo_alloc(elsize * nelem))) {
> +    if (!(rmq->fifo = av_fifo_alloc2(nelem, elsize, 0))) {
>          pthread_cond_destroy(&rmq->cond_send);
>          pthread_cond_destroy(&rmq->cond_recv);
>          pthread_mutex_destroy(&rmq->lock);
> @@ -107,9 +107,9 @@ int av_thread_message_queue_nb_elems(AVThreadMessageQueue *mq)
>  #if HAVE_THREADS
>      int ret;
>      pthread_mutex_lock(&mq->lock);
> -    ret = av_fifo_size(mq->fifo);
> +    ret = av_fifo_can_read(mq->fifo);
>      pthread_mutex_unlock(&mq->lock);
> -    return ret / mq->elsize;
> +    return ret;
>  #else
>      return AVERROR(ENOSYS);
>  #endif
> @@ -121,14 +121,14 @@ 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) {
> +    while (!mq->err_send && !av_fifo_can_write(mq->fifo)) {
>          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);
> +    av_fifo_write(mq->fifo, msg, 1);
>      /* one message is sent, signal one receiver */
>      pthread_cond_signal(&mq->cond_recv);
>      return 0;
> @@ -138,14 +138,14 @@ 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) {
> +    while (!mq->err_recv && !av_fifo_can_read(mq->fifo)) {
>          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)
> +    if (!av_fifo_can_read(mq->fifo))
>          return mq->err_recv;
> -    av_fifo_generic_read(mq->fifo, msg, mq->elsize, NULL);
> +    av_fifo_read(mq->fifo, msg, 1);
>      /* one message space appeared, signal one sender */
>      pthread_cond_signal(&mq->cond_send);
>      return 0;
> @@ -208,25 +208,25 @@ void av_thread_message_queue_set_err_recv(AVThreadMessageQueue *mq,
>  }
>  
>  #if HAVE_THREADS
> -static void free_func_wrap(void *arg, void *msg, int size)
> +static int free_func_wrap(void *arg, void *buf, size_t *nb_elems)
>  {
>      AVThreadMessageQueue *mq = arg;
> -    mq->free_func(msg);
> +    uint8_t *msg = buf;
> +    for (size_t i = 0; i < *nb_elems; i++)
> +        mq->free_func(msg + i * mq->elsize);
> +    return 0;

This function (like most nontrivial callbacks) relies on buf being
suitably aligned for whatever type msg is. Therefore one should document
that the src/dst in the callbacks is always suitable aligned for all
non-over-aligned types.

>  }
>  #endif
>  
>  void av_thread_message_flush(AVThreadMessageQueue *mq)
>  {
>  #if HAVE_THREADS
> -    int used, off;
> -    void *free_func = mq->free_func;
> +    size_t used;
>  
>      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);
> +    used = av_fifo_can_read(mq->fifo);
> +    if (mq->free_func)
> +        av_fifo_read_to_cb(mq->fifo, free_func_wrap, mq, &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);
> 



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