[linux-audio-dev] realtimeness: pthread_cond_signal vs. pipe write

[Dave Robillard]

On Wed, 2006-06-07 at 17:42 -0400, Lee Revell wrote:
> On Wed, 2006-06-07 at 20:32 +0200, Fons Adriaensen wrote:
> > On Wed, Jun 07, 2006 at 08:49:38AM -0400, Paul Davis wrote:
> > 
> > > nice to hear that they are faster. on the other hand, once again POSIX
> > > screws us all over by not integrating everything into a single blocking
> > > wait call. i've said it before, i'll say it again - this is one of the
> > > few things that the win32 API gets right - you can block in one call on
> > > almost *anything*. AFAICT, you cannot select/poll on a msg queue.
> > 
> > You can build such a thing on top of condition variables - that
> > is what they exists for - to let a thread wait one any condition
> > you may want, no matter how complicated. 
> > 
> 
> But, from the original post it seems that pthread_cond_signal is not
> realtime safe as it locks a mutex:

The big question is: who cares? :)  sem_post() is.  A mutex/cond pair is
just a big ugly slow non-RT-safe semaphore anyway.

-DR-