[squeak-dev] Sound latchup problem is back with Squeak- (Ubuntu/Linux)

Derek O'Connell doconnel at gmail.com
Wed Apr 14 07:46:34 UTC 2010

Hi Jerome, the previous version only appeared to play correctly for 
short sounds but if you try a sustained note using the PianoKeyboard 
morph the sound will be choppy.

The high CPU usage is caused by the SoundPlayer process that feeds data 
to the plugin. There is a preference under "media" called 
"soundStopWhenDone" which, if enabled, stops the process when the sound 
queue is empty and brings CPU usage back down to normal. Alternatively 
issue "SoundPlayer stopPlayerProcess".

For background: previously the player process would query a sound plugin 
for available buffer space and wait on a semaphore if low. The PA plugin 
has additional buffering and threading which effectively makes this 
check redundant.


On 14/04/10 04:52, Jerome Peace wrote:
> Doing Beeper beep causes the cpu to latch to 100% for squeakvm and pulseaudio.
> This problem was thought solved with
> Squeak-
> but has regressed with this newer version:
> Squeak-
> Someone should warn the Pharo folk.
> Yours in curiosity and service, --Jerome Peace
> "Testing" is for when you are still guessing. --Agatha Heterodyne
> http://www.girlgeniusonline.com/comic.php

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