[Vm-dev] Re: Re: How does Time>millisecondClockValue get a resolution of 1 millisecond?

[Eliot Miranda]

On Wed, Aug 8, 2012 at 3:22 PM, Louis LaBrunda <Lou at keystone-software.com>wrote:

>
> Hi Eliot,
>
> >Oh, and importantly, the VM ups the resolution of timeGetTime() via
> timeBeginPeriod to 1 millisecond if possible.
>
> Thanks for the replies.  One more question, what is used for Linux or UNIX
> systems?  I would like to recommend to Instantiations (VA Smalltalk) that
> they change to functions that give a finer resolution than GetTickCount
> (which is what I think they or IBM use).
>

gettimeofday.  On linux this does'nt necessarily have great resolution.  On
Mac OS it has > 1ms resolution.


>
> The current VA Smalltalk code in this area asks for a timer interrupt every
> 100 milliseconds.  It then checks delays and callback that have been posted
> to see if any need to expire.  So, you can't really do a delay for less
> than 100 milliseconds.  Even though there are places in the base code that
> sets delays at less than 100 milliseconds.
>
> I have a few programs where this is a problem.  There is a method where I
> can drop the interrupt period and I have used it to set the interrupt
> period to 10 milliseconds and that helps my programs greatly.  But it
> really only drops the resolution to 15 milliseconds.
>
> I would like to point Instantiations to the functions that will give a 1
> millisecond resolution on all the systems they support.
>
> Many thanks.
>
> Lou
> -----------------------------------------------------------
> Louis LaBrunda
> Keystone Software Corp.
> SkypeMe callto://PhotonDemon
> mailto:Lou at Keystone-Software.com http://www.Keystone-Software.com
>
>


-- 
best,
Eliot
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