[FFmpeg-devel] [PATCH] lavu/threadmessage: add av_thread_message_queue_nelem()

[Rostislav Pehlivanov]

On 21 April 2018 at 20:51, Clément Bœsch <u at pkh.me> wrote:

> ---
> Been away from FFmpeg for way too long. Hope this patch get me back on
> track. Feel free to nitpick on the name.
> ---
>  doc/APIchanges                     | 3 +++
>  libavutil/threadmessage.c          | 9 +++++++++
>  libavutil/threadmessage.h          | 5 +++++
>  libavutil/version.h                | 2 +-
>  tests/api/api-threadmessage-test.c | 4 +++-
>  5 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/doc/APIchanges b/doc/APIchanges
> index 4f6ac2a031..393491c8e9 100644
> --- a/doc/APIchanges
> +++ b/doc/APIchanges
> @@ -15,6 +15,9 @@ libavutil:     2017-10-21
>
>  API changes, most recent first:
>
> +2018-04-xx - xxxxxxxxxx - lavu 56.16.100 - threadmessage.h
> +  Add av_thread_message_queue_nelem().
> +
>  -------- 8< --------- FFmpeg 4.0 was cut here -------- 8< ---------
>
>  2018-04-03 - d6fc031caf - lavu 56.13.100 - pixdesc.h
> diff --git a/libavutil/threadmessage.c b/libavutil/threadmessage.c
> index 872e9392b1..fed398926a 100644
> --- a/libavutil/threadmessage.c
> +++ b/libavutil/threadmessage.c
> @@ -102,6 +102,15 @@ void av_thread_message_queue_free(AVThreadMessageQueue
> **mq)
>  #endif
>  }
>
> +int av_thread_message_queue_nelem(AVThreadMessageQueue *mq)
> +{
> +    int ret;
> +    pthread_mutex_lock(&mq->lock);
> +    ret = av_fifo_size(mq->fifo);
> +    pthread_mutex_unlock(&mq->lock);
> +    return ret / mq->elsize;
> +}
> +
>  #if HAVE_THREADS
>
>  static int av_thread_message_queue_send_locked(AVThreadMessageQueue *mq,
> diff --git a/libavutil/threadmessage.h b/libavutil/threadmessage.h
> index 8480a0a3db..e41d95ccf7 100644
> --- a/libavutil/threadmessage.h
> +++ b/libavutil/threadmessage.h
> @@ -95,6 +95,11 @@ void av_thread_message_queue_set_err_recv(AVThreadMessageQueue
> *mq,
>  void av_thread_message_queue_set_free_func(AVThreadMessageQueue *mq,
>                                             void (*free_func)(void *msg));
>
> +/**
> + * Return the current number of messages in the queue.
> + */
> +int av_thread_message_queue_nelem(AVThreadMessageQueue *mq);
> +
>  /**
>   * Flush the message queue
>   *
> diff --git a/libavutil/version.h b/libavutil/version.h
> index 387421775f..23567000a3 100644
> --- a/libavutil/version.h
> +++ b/libavutil/version.h
> @@ -79,7 +79,7 @@
>   */
>
>  #define LIBAVUTIL_VERSION_MAJOR  56
> -#define LIBAVUTIL_VERSION_MINOR  15
> +#define LIBAVUTIL_VERSION_MINOR  16
>  #define LIBAVUTIL_VERSION_MICRO 100
>
>  #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
> diff --git a/tests/api/api-threadmessage-test.c
> b/tests/api/api-threadmessage-test.c
> index 05a8062b8c..494808f176 100644
> --- a/tests/api/api-threadmessage-test.c
> +++ b/tests/api/api-threadmessage-test.c
> @@ -130,7 +130,9 @@ static void *receiver_thread(void *arg)
>
>      for (i = 0; i < rd->workload; i++) {
>          if (rand() % rd->workload < rd->workload / 10) {
> -            av_log(NULL, AV_LOG_INFO, "receiver #%d: flushing the
> queue\n", rd->id);
> +            av_log(NULL, AV_LOG_INFO, "receiver #%d: flushing the queue, "
> +                   "discarding %d message(s)\n", rd->id,
> +                   av_thread_message_queue_nelem(rd->queue));
>              av_thread_message_flush(rd->queue);
>          } else {
>              struct message msg;
> --
> 2.17.0
>
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> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>

I think av_thread_message_queue_elems would be a better name, had to think
for a good period of time what "nelem" meant.