[pulseaudio-discuss] [PATCH RFCv3 49/51] alsa: Refactor computation of sleep usec

[Peter Meerwald]

> > avoids duplicate code in mmap_read/write() and unix_read/write()
> 
> Looks good, but in the name of optimisation I would have expected these 
> to be inlined...?

the compiler is free to do so...

p.

> >   src/modules/alsa/alsa-sink.c   | 57
> +++++++++++++++++-------------------------
> >   src/modules/alsa/alsa-source.c | 35 +++++++++++++-------------
> >   2 files changed, 40 insertions(+), 52 deletions(-)
> >
> > diff --git a/src/modules/alsa/alsa-sink.c b/src/modules/alsa/alsa-sink.c
> > index 0d13716..aab7ee7 100644
> > --- a/src/modules/alsa/alsa-sink.c
> > +++ b/src/modules/alsa/alsa-sink.c
> > @@ -508,10 +508,29 @@ static size_t check_left_to_play(struct userdata *u,
> size_t n_bytes, bool on_tim
> >       return left_to_play;
> >   }
> >
> > +static pa_usec_t compute_sleep(struct userdata *u, size_t left_to_play) {
> > +    size_t input_underrun = pa_sink_process_input_underruns(u->sink,
> left_to_play);
> > +    pa_usec_t sleep_usec = 0;
> > +
> > +    if (u->use_tsched) {
> > +        pa_usec_t underrun_sleep =
> pa_bytes_to_usec_round_up(input_underrun, &u->sink->sample_spec);
> > +        sleep_usec = PA_BYTES_TO_USEC(left_to_play, &u->sink->sample_spec);
> > +
> > +        if (sleep_usec > u->tsched_watermark_usec)
> > +            sleep_usec -= u->tsched_watermark_usec;
> > +        else
> > +            sleep_usec = 0;
> > +
> > +        sleep_usec = PA_MIN(sleep_usec, underrun_sleep);
> > +    }
> > +
> > +    return sleep_usec;
> > +}
> > +
> >   static int mmap_write(struct userdata *u, pa_usec_t *sleep_usec, bool
> polled, bool on_timeout) {
> >       bool work_done = false;
> >       pa_usec_t max_sleep_usec = 0, process_usec = 0;
> > -    size_t left_to_play, input_underrun;
> > +    size_t left_to_play;
> >       size_t sleep_bytes = 0;
> >       unsigned j = 0;
> >
> > @@ -683,22 +702,7 @@ static int mmap_write(struct userdata *u, pa_usec_t
> *sleep_usec, bool polled, bo
> >       }
> >
> >   done:
> > -    input_underrun = pa_sink_process_input_underruns(u->sink,
> left_to_play);
> > -
> > -    if (u->use_tsched) {
> > -        pa_usec_t underrun_sleep =
> pa_bytes_to_usec_round_up(input_underrun, &u->sink->sample_spec);
> > -
> > -        *sleep_usec = PA_BYTES_TO_USEC(left_to_play,
> &u->sink->sample_spec);
> > -        process_usec = u->tsched_watermark_usec;
> > -
> > -        if (*sleep_usec > process_usec)
> > -            *sleep_usec -= process_usec;
> > -        else
> > -            *sleep_usec = 0;
> > -
> > -        *sleep_usec = PA_MIN(*sleep_usec, underrun_sleep);
> > -    } else
> > -        *sleep_usec = 0;
> > +    *sleep_usec = compute_sleep(u, left_to_play);
> >
> >       return work_done ? 1 : 0;
> >   }
> > @@ -706,7 +710,7 @@ done:
> >   static int unix_write(struct userdata *u, pa_usec_t *sleep_usec, bool
> polled, bool on_timeout) {
> >       bool work_done = false;
> >       pa_usec_t max_sleep_usec = 0, process_usec = 0;
> > -    size_t left_to_play, input_underrun;
> > +    size_t left_to_play;
> >       unsigned j = 0;
> >
> >       pa_assert(u);
> > @@ -837,22 +841,7 @@ static int unix_write(struct userdata *u, pa_usec_t
> *sleep_usec, bool polled, bo
> >           }
> >       }
> >
> > -    input_underrun = pa_sink_process_input_underruns(u->sink,
> left_to_play);
> > -
> > -    if (u->use_tsched) {
> > -        pa_usec_t underrun_sleep =
> pa_bytes_to_usec_round_up(input_underrun, &u->sink->sample_spec);
> > -
> > -        *sleep_usec = PA_BYTES_TO_USEC(left_to_play,
> &u->sink->sample_spec);
> > -        process_usec = u->tsched_watermark_usec;
> > -
> > -        if (*sleep_usec > process_usec)
> > -            *sleep_usec -= process_usec;
> > -        else
> > -            *sleep_usec = 0;
> > -
> > -        *sleep_usec = PA_MIN(*sleep_usec, underrun_sleep);
> > -    } else
> > -        *sleep_usec = 0;
> > +    *sleep_usec = compute_sleep(u, left_to_play);
> >
> >       return work_done ? 1 : 0;
> >   }
> > diff --git a/src/modules/alsa/alsa-source.c b/src/modules/alsa/alsa-source.c
> > index f82f811..ac88e4b 100644
> > --- a/src/modules/alsa/alsa-source.c
> > +++ b/src/modules/alsa/alsa-source.c
> > @@ -477,6 +477,21 @@ static size_t check_left_to_record(struct userdata *u,
> size_t n_bytes, bool on_t
> >       return left_to_record;
> >   }
> >
> > +static pa_usec_t compute_sleep(struct userdata *u, size_t left_to_record) {
> > +    pa_usec_t sleep_usec = 0;
> > +
> > +    if (u->use_tsched) {
> > +        sleep_usec = PA_BYTES_TO_USEC(left_to_record,
> &u->source->sample_spec);
> > +
> > +        if (sleep_usec > u->tsched_watermark_usec)
> > +            sleep_usec -= u->tsched_watermark_usec;
> > +        else
> > +            sleep_usec = 0;
> > +    }
> > +
> > +    return sleep_usec;
> > +}
> > +
> >   static int mmap_read(struct userdata *u, pa_usec_t *sleep_usec, bool
> polled, bool on_timeout) {
> >       bool work_done = false;
> >       pa_usec_t max_sleep_usec = 0, process_usec = 0;
> > @@ -625,15 +640,7 @@ static int mmap_read(struct userdata *u, pa_usec_t
> *sleep_usec, bool polled, boo
> >           }
> >       }
> >
> > -    if (u->use_tsched) {
> > -        *sleep_usec = PA_BYTES_TO_USEC(left_to_record,
> &u->source->sample_spec);
> > -        process_usec = u->tsched_watermark_usec;
> > -
> > -        if (*sleep_usec > process_usec)
> > -            *sleep_usec -= process_usec;
> > -        else
> > -            *sleep_usec = 0;
> > -    }
> > +    *sleep_usec = compute_sleep(u, left_to_record);
> >
> >       return work_done ? 1 : 0;
> >   }
> > @@ -755,15 +762,7 @@ static int unix_read(struct userdata *u, pa_usec_t
> *sleep_usec, bool polled, boo
> >           }
> >       }
> >
> > -    if (u->use_tsched) {
> > -        *sleep_usec = PA_BYTES_TO_USEC(left_to_record,
> &u->source->sample_spec);
> > -        process_usec = u->tsched_watermark_usec;
> > -
> > -        if (*sleep_usec > process_usec)
> > -            *sleep_usec -= process_usec;
> > -        else
> > -            *sleep_usec = 0;
> > -    }
> > +    *sleep_usec = compute_sleep(u, left_to_record);
> >
> >       return work_done ? 1 : 0;
> >   }
> >
> 
> 

-- 

Peter Meerwald
+43-664-2444418 (mobile)