[vlc-devel] [PATCH 2/2] aout: wasapi: use a vlc_timer for the deferred start

[Rémi Denis-Courmont]

Le tiistaina 9. kesäkuuta 2020, 17.48.48 EEST Steve Lhomme a écrit :
> The timer API is not supported in Winstore builds so switch to something
> that works for all.
> ---
>  modules/audio_output/wasapi.c | 41 ++++++++++++++++-------------------
>  1 file changed, 19 insertions(+), 22 deletions(-)
> 
> diff --git a/modules/audio_output/wasapi.c b/modules/audio_output/wasapi.c
> index ecfcc99ae1dd..3644d7cea5ae 100644
> --- a/modules/audio_output/wasapi.c
> +++ b/modules/audio_output/wasapi.c
> @@ -91,7 +91,8 @@ static msftime_t GetQPC(void)
>  typedef struct aout_stream_sys
>  {
>      IAudioClient *client;
> -    HANDLE hTimer;
> +    vlc_timer_t timer;
> +    atomic_bool has_timer;
> 
>  #define STARTED_STATE_INIT 0
>  #define STARTED_STATE_OK 1
> @@ -112,11 +113,8 @@ typedef struct aout_stream_sys
>  static void ResetTimer(aout_stream_t *s)
>  {
>      aout_stream_sys_t *sys = s->sys;
> -    if (sys->hTimer != NULL)
> -    {
> -        DeleteTimerQueueTimer(NULL, sys->hTimer, INVALID_HANDLE_VALUE);
> -        sys->hTimer = NULL;
> -    }
> +    if (atomic_exchange(&sys->has_timer,false))
> +        vlc_timer_destroy(sys->timer);
>  }
> 
>  /*** VLC audio output callbacks ***/
> @@ -160,7 +158,7 @@ static HRESULT TimeGet(aout_stream_t *s, vlc_tick_t
> *restrict delay) return hr;
>  }
> 
> -static void DoStartDeferred(void *val)
> +static void StartDeferredCallback(void *val)
>  {
>      aout_stream_t *s = val;
>      aout_stream_sys_t *sys = s->sys;
> @@ -169,25 +167,24 @@ static void DoStartDeferred(void *val)
>      atomic_store(&sys->started_state,
>                   SUCCEEDED(hr) ? STARTED_STATE_OK : STARTED_STATE_ERROR);
>  }
> -static void CALLBACK StartDeferredCallback(void *val, BOOLEAN timeout)
> -{
> -    DoStartDeferred(val);
> -    (void)timeout;
> -}
> 
>  static bool StartTimer(aout_stream_t *s, vlc_tick_t start_delay)
>  {
>      aout_stream_sys_t *sys = s->sys;
>      bool timer_updated = false;
> -    DWORD start_delay_ms = MS_FROM_VLC_TICK(start_delay);
> -    if (sys->hTimer == NULL)
> -        timer_updated =
> -            CreateTimerQueueTimer(&sys->hTimer, NULL,
> StartDeferredCallback, -                                    s,
> start_delay_ms, 0,
> -                                    WT_EXECUTEDEFAULT |
> WT_EXECUTEONLYONCE); -    else
> -        timer_updated =
> -            ChangeTimerQueueTimer(NULL, sys->hTimer, start_delay_ms, 0);
> +    if (!atomic_load(&sys->has_timer))

I don't follow how the atomic works here. It looks like it's either 
unnecessary or insufficient, as it would race with vlc_timer_create().

> +    {
> +        if (vlc_timer_create( &sys->timer, StartDeferredCallback, s ) == 0)
> +        {
> +            msg_Warn(s, "start THREAD!");
> +            atomic_store(&sys->has_timer, true);
> +        }
> +    }
> +    if (atomic_load(&sys->has_timer))
> +    {
> +        vlc_timer_schedule( sys->timer, false, start_delay, 0);
> +        timer_updated = true;
> +    }
>      return timer_updated;
>  }
> 
> @@ -759,7 +756,7 @@ static HRESULT Start(aout_stream_t *s,
> audio_sample_format_t *restrict pfmt, if (unlikely(sys == NULL))
>          return E_OUTOFMEMORY;
>      sys->client = NULL;
> -    sys->hTimer = NULL;
> +    atomic_init(&sys->has_timer, false);
>      atomic_init(&sys->started_state, STARTED_STATE_INIT);
> 
>      /* Configure audio stream */


-- 
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