High priority on NT ?

Richard Dobson rwd at cableinet.co.uk
Wed Nov 24 23:46:56 CET 1999


It's already at HIGH_PRIORITY_CLASS, which I think is high enough; the
only remaining level above that is REALTIME_PRIORITY_CLASS, which would
probably be fairly lethal, as it preempts virtually all system activity,
including disk flushes, and will of course freeze the screen. Even
CTRL_ALT_DEL may not work. It is essential for me that I can rely on
this means of killing an unresponsive program.

At present, PD is mostly single-tasking, not least because the audio is
handled by polling the drivers (rather than by using callbacks or
waiting on events). By adding a Sleep(1) call inside the polling
(RESYNC) loops, control can be returned to the NT scheduler, so that the
user interface can be updated. It also makes the polling loop less
affected by different processor peeds.

I am getting fairly useful performance from PD this way, and would not
like the GUI to be frozen out. 

Other speed-up solutions would require more designed multi-threading,
and ultimately placing the audio engine at Kernel level as a Device, in
some way. TK itself is pretty slow - of course, a fully native-Windows
GUI implementation would give a significant speed-up. Or port the whole
thing to the Creamware SCOPE system!

Richard Dobson

Guenter Geiger wrote:
> 
> Hi there !
> 
> Does anyone know how I can give higher priority to pd under
> Windows NT ?
> 
> Thanks in advance
> 
> Guenter

-- 
Test your DAW with my Soundcard Attrition Page!
http://wkweb5.cableinet.co.uk/rwd (LU: 17th September 1999)
CDP: http://www.bath.ac.uk/~masjpf/CDP/CDP.htm (LU: 4th November 1999)



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