Re: [Qemu-devel] Re: [PATCH V4 2/3] qemu: Generic task offloading framework: threadlets

[Paolo Bonzini]

On 06/16/2010 05:07 PM, Jamie Lokier wrote:
> Putting the whole condition inside the mutex->cond_wait region, not
> just empty queue test, will remove the need for timed wait.

Yes, the condition must include all the cases when you broadcast.

> Broadcast
> is still needed, or alternatively a cond_signal from each exiting
> thread will allow them to wake and close without a thundering herd.

If the pthreads cause a thundering herd, that's the pthreads problem.  A 
properly implemented condvar will just requeue the threads to the mutex. 
 NPTL does, the Win32 condvar most likely won't. :)

Anyway if Corentin doesn't need the flush_threadlets_queue all this can 
be dropped.

Paolo