[Vm-dev] [Pharo-dev] Problem with OSSubprocess / signals / heartbeat ?

Petr Fischer petr.fischer at me.com
Sat Apr 1 19:11:15 UTC 2017


> On Thu, 30 Mar 2017, Eliot Miranda wrote:
> 
> > Once the active process is in a tight loop the delay is effectively
> disabled because the tight loop effectively shuts out the heartbeat thread
> and hence the system never notices that the delay has expired.
> 
> I think that won't happen, because the process scheduler (O(1), CFS, BFS) on
> linux is not cooperative. So, the kernel will periodically preempt the main
> thread and run the heartbeat thread no matter what their priorities are. The
> higher priority only provides lower jitter on the heartbeat thread.
> 
> Levente

Is there some test case or code, that I can run in Pharo and evaluate if kernel sheduler is working correctly (with heartbeat thread at normal priority).
I need to test it under FreeBSD.

Thanks! pf


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