The VM's attempt to provide 1 or 2 millisecond timing for servicing  
Delays.  I believe the windows VM offered 1 millisecond timing for  
awhile now.
The macintosh carbon and I guess the Unix Vm offer timing resolution  
historically in about a 2 or 3 ms window, but I see the code to do  
that has been
changed now to target a  1 ms window via the interpreter's setting of  
interruptChecksEveryNms, we did this 2004 I'd guess.

You could consider creating a set of Delays to fire in the future,  
have some task responsible for doing this based on the timing that  
you require, or you setup up
a delay to service the next task at the end of each task completion,  
and by tracking the latency (if any) you could ensure your code will  
run within a 1ms window.

Internally the VM attempts to check every millisecond for pending  
delays, or when not busy, sleeps until the next interrupt is required  
to be fired (or of course wakes up when an signal, or UI interrupt is  
needed to be serviced).

On Jan 28, 2007, at 11:13 AM, Cesare Marilungo wrote:

> Stéphane Rollandin wrote:
>> hello list,
>>
>> a new development snapshot of muO is available:
>> http://www.zogotounga.net/comp/squeak/sqgeo.htm
>>
>> it can be installed in a 3.8 or 3.9 image (use fresh images for  
>> safety
>> and convenience)
>>
>> muO is an experimental environment for musical composition
>>
>>
>> Stef
>>
>>
>>
>>
> Hi Stef,
>
> I've installed muO and started studying the documentation. It looks  
> really interesting.
>
> I was working on a music project in squeak, too.
>
> I wrote some morphs to represent notes and envelopes and wanted to  
> send events via OSC in realtime.
>
> But I'm stuck since I haven't found how to keep precise timing  
> (with a decent resolution). My first prototypes used the Morph  
> 'tick' method, but this was unacceptable for obvious reasons.  
> Lately I've been experimenting with forking an osProcess, but I was  
> wandering if there's a cleaner/better method.
>
> Can you provide me with some hints, or point me to the proper  
> documentation where I can found some explanation about how to  
> achieve this?
>
> Thanks in advance, and keep up with the good work.
>
> c.
>
> -- 
> http://www.cesaremarilungo.com
>
>

--
======================================================================== 
===
John M. McIntosh <johnmci at smalltalkconsulting.com>
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
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===