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RE: THREAD_TIME_CONSTRAINT_POLICY

Try configuring your thread with a high fixed priority. In most cases,
people don't really need to use time constraint threads.

The archives of the coreaudio-api list have a series of good discussions
about real-time threading issues on OS X.

-chris

> -----Original Message-----
> From: email@hidden
[mailto:darwin-development-
> email@hidden] On Behalf Of Peter April
> Sent: Wednesday, February 18, 2004 9:55 PM
> To: email@hidden
> Subject: THREAD_TIME_CONSTRAINT_POLICY
>
> Hello,
>
> I'm calling thread_policy_set() with THREAD_TIME_CONSTRAINT_POLICY to
> improve the performance of a real-time thread. I notice that under OS
X
> 10.2.8 for 1.8GHz G5, thread_policy_set returns a PARAM_ERROR (4) if I
> pass it tcPolicy.computation greater than about 1600000, corresponding
> to about 1.8 milliseconds. This limitation is independant of the
value
> I pass in tcPolicy.period and tcPolicy.preemptible. I can't figure
out
> why the scheduler would choke on my request for a larger chunk of CPU
> time. What's really odd is that thread_policy_set() returns
> KERN_SUCCESS even if I request tcPolicy.period/computation/constraint
> all set to 1600000, presumably smiling upon my request for 100% of the
> CPU time! Of course, the irritating part of all this is that no
matter
> what I pass, my thread still gets thrown out for up to 10ms at a time,
> even if I'm the only app running, trueblue is shutdown, and the update
> task has been killed :(
> Any pointers on improving real-time performance would be greatly
> appreciated.
>
> -Peter
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