[pulseaudio-tickets] [PulseAudio] #866: pa_simple_drain() takes much longer (about 2000ms) than expected to complete

[PulseAudio]

#866: pa_simple_drain() takes much longer (about 2000ms) than expected to
complete
---------------------+------------------------------------------------------
  Reporter:  th      |       Owner:  lennart 
      Type:  defect  |      Status:  new     
 Milestone:          |   Component:  libpulse
Resolution:          |    Keywords:          
---------------------+------------------------------------------------------

Comment(by th):

 I ran the test program with pulse running with verbose logging, if you
 look at the Launchpad bug entry you can see it:

 [https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/660567] (also
 pasted below).

 It seems that pulse gets a buffer underrun at the time that I would expect
 pa_simple_drain() to return, but it doesn't, and waits for 2s after that.
 In simplistic terms, I guess pa_simple_drain() could be thought of as
 "wait for buffer underrun", but for some reason it doesn't signal the
 client when the buffer runs out.

 {{{
 ...
 ( 0.034| 0.000) D: source.c: Processing rewind...
 [0.344269] play done
 [0.344328] not calling pa_simple_drain()
 [0.358380] playing 680 hz tone volume 50 for 500 ms
 [0.829451] play done
 [0.829489] not calling pa_simple_drain()
 [0.840411] playing 440 hz tone volume 50 for 500 ms
 [1.303775] play done
 ( 1.471| 1.437) D: protocol-native.c: Underrun on 'beep', 0 bytes in
 queue.
 [3.505551] pa_simple_drain() done
 [3.519491] playing 680 hz tone volume 50 for 500 ms
 ( 3.532| 2.060) D: protocol-native.c: Requesting rewind due to end of
 underrun.
 ( 3.532| 0.000) D: alsa-sink.c: Requested to rewind 10156 bytes.
 ( 3.532| 0.000) D: alsa-sink.c: Limited to 10156 bytes.
 ( 3.532| 0.000) D: alsa-sink.c: before: 2539
 ( 3.532| 0.000) D: alsa-sink.c: after: 2539
 ( 3.532| 0.000) D: alsa-sink.c: Rewound 10156 bytes.
 ( 3.532| 0.000) D: sink.c: Processing rewind...
 ( 3.532| 0.000) D: sink-input.c: Have to rewind 10156 bytes on render
 memblockq.
 ( 3.533| 0.000) D: source.c: Processing rewind...
 [3.848197] play done
 ( 4.016| 0.483) D: protocol-native.c: Underrun on 'beep', 0 bytes in
 queue.
 [6.050165] pa_simple_drain() done
 [6.062775] playing 440 hz tone volume 50 for 500 ms
 ...
 }}}

-- 
Ticket URL: <http://pulseaudio.org/ticket/866#comment:6>
PulseAudio <http://pulseaudio.org/>
The PulseAudio Sound Server