[vlc-devel] [PATCH 02/17] clock: allow to return VLC_TICK_INVALID from convert calls

[Rémi Denis-Courmont]

Le maanantaina 15. helmikuuta 2021, 12.14.57 EET Thomas Guillem a écrit :
> For now, when the main clock is reset, vlc_clock_ConvertToSystem() won't
> return VLC_TICK_INVALID since it will fallback to
> vlc_clock_monotonic_to_system_locked() but this behavior will change in
> next commits.

As I recall, we had agreed that timestamping must never fail?

> ---
>  src/clock/clock.c | 17 ++++++++++++++++-
>  src/clock/clock.h | 12 ++++++++----
>  2 files changed, 24 insertions(+), 5 deletions(-)
> 
> diff --git a/src/clock/clock.c b/src/clock/clock.c
> index cfbb5eb6f6d..32f6b573632 100644
> --- a/src/clock/clock.c
> +++ b/src/clock/clock.c
> @@ -306,6 +306,8 @@ static vlc_tick_t vlc_clock_slave_update(vlc_clock_t
> *clock, vlc_tick_t computed = clock->to_system_locked(clock, system_now,
> ts, rate);
> 
>      vlc_mutex_unlock(&main_clock->lock);
> +    if (computed == VLC_TICK_INVALID)
> +        return computed;
> 
>      vlc_clock_on_update(clock, computed, ts, rate, frame_rate,
> frame_rate_base); return computed - system_now;
> @@ -349,7 +351,11 @@ void vlc_clock_Wait(vlc_clock_t *clock, vlc_tick_t
> system_now, vlc_tick_t ts, if (main_clock->pause_date != VLC_TICK_INVALID)
>              deadline = INT64_MAX;
>          else
> +        {
>              deadline = clock->to_system_locked(clock, system_now, ts,
> rate); +            if (deadline == VLC_TICK_INVALID)
> +                break;
> +        }
>          deadline = __MIN(deadline, max_deadline);
> 
>          if (vlc_cond_timedwait(&main_clock->cond, &main_clock->lock,
> deadline)) @@ -508,16 +514,25 @@ vlc_tick_t
> vlc_clock_ConvertToSystem(vlc_clock_t *clock, vlc_tick_t system_now, return
> system;
>  }
> 
> -void vlc_clock_ConvertArrayToSystem(vlc_clock_t *clock, vlc_tick_t
> system_now, +int vlc_clock_ConvertArrayToSystem(vlc_clock_t *clock,
> vlc_tick_t system_now, vlc_tick_t *ts_array, size_t ts_count, double rate)
>  {
>      vlc_clock_main_t *main_clock = clock->owner;
>      vlc_mutex_lock(&main_clock->lock);
>      for (size_t i = 0; i < ts_count; ++i)
> +    {
>          ts_array[i] = clock->to_system_locked(clock, system_now,
> ts_array[i], rate);
> +        if (ts_array[i] == VLC_TICK_INVALID)
> +        {
> +            vlc_mutex_unlock(&main_clock->lock);
> +            return VLC_EGENERIC;
> +        }
> +    }
>      vlc_mutex_unlock(&main_clock->lock);
> +
> +    return VLC_SUCCESS;
>  }
> 
>  static void vlc_clock_set_master_callbacks(vlc_clock_t *clock)
> diff --git a/src/clock/clock.h b/src/clock/clock.h
> index e7373391697..b852af0eb23 100644
> --- a/src/clock/clock.h
> +++ b/src/clock/clock.h
> @@ -168,16 +168,20 @@ void vlc_clock_Wait(vlc_clock_t *clock, vlc_tick_t
> system_now, vlc_tick_t ts,
> 
>  /**
>   * This function converts a timestamp from stream to system
> - * @return the valid system time or INT64_MAX when the clock is paused
> + * @return the valid system time, INT64_MAX when the clock is paused or
> + * VLC_TICK_INVALID when the main clock is reset (the master source is
> flushed). */
>  vlc_tick_t vlc_clock_ConvertToSystem(vlc_clock_t *clock, vlc_tick_t
> system_now, vlc_tick_t ts, double rate);
> 
>  /**
>   * This functon converts an array of timestamp from stream to system
> + *
> + * @return VLC_SUCCESS or VLC_EGENERIC if the clock is reset (the master
> source + * is flushed).
>   */
> -void vlc_clock_ConvertArrayToSystem(vlc_clock_t *clock, vlc_tick_t
> system_now, -                                    vlc_tick_t *ts_array,
> size_t ts_count, -                                    double rate);
> +int vlc_clock_ConvertArrayToSystem(vlc_clock_t *clock, vlc_tick_t
> system_now, +                                   vlc_tick_t *ts_array,
> size_t ts_count, +                                   double rate);
> 
>  #endif /*VLC_CLOCK_H*/


-- 
Rémi Denis-Courmont
http://www.remlab.net/