Julian,

The constraints parameters were ignored in the kernel for many generations of 
OS X in spite of the documentation defining their use. The real documentation 
(the source code) said otherwise.

I am not sure if they are still ignored, IIRC the kernel-side code is not hard 
to find to check.

Tim.


On 31 May 2016, at 20:00, [email protected] wrote:

> Hi,
> 
> I'm trying to create real-time threads via the
> THREAD_TIME_CONSTRAINT_POLICY.
> It works fine, an interrupt after each computation cycle can be seen inside
> the profiler (Instruments / System Trace) but the constraint seems to be
> ignored.
> 
> I would expect a penalty after the constraint time is over but the thread
> stays on the CPU starving other threads.
> 
> That's the way I initialize the time constraint policy:
> 
>    thread_time_constraint_policy_data_t time_constraints;
> 
>    time_constraints.period = (int) NanosecondsToAbsolute (1000000); // 1
> ms
> 
>    time_constraints.computation = (int) NanosecondsToAbsolute (250000); //
> 0.25 ms
> 
>    time_constraints.constraint = (int) NanosecondsToAbsolute(500000); //
> 0.5 ms
> 
>    time_constraints.preemptible = 1;
> 
>    thread_policy_set(mach_thread_self (), THREAD_TIME_CONSTRAINT_POLICY,
> (thread_policy_t) &time_constraints, THREAD_TIME_CONSTRAINT_POLICY_COUNT);
> 
> Any ideas how to get the constraint working?
> 
> Regards,
> Julian


 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list      ([email protected])
Help/Unsubscribe/Update your Subscription:
https://lists.apple.com/mailman/options/coreaudio-api/archive%40mail-archive.com

This email sent to [email protected]

Reply via email to