[PD-dev] 0.43 startup procedure and vwait WAS: [PATCH 06/10] fixed race-condition in the audio/midi API initialization

[Miller Puckette]

I think the wait4pd thing was serving a valid purpose but the way it worked
had race conditions... OTOH, waiting for pd to timeout and doing something
appropriate (like telling the user something then giving up) sounds like a
good thing to do - but is it appropriate to have the gui just exit?  Shouldn't
it offer to kill the errant pd or something?

cheers
Miller

On Thu, Jul 15, 2010 at 05:07:22PM +0200, IOhannes zm?lnig wrote:
> On 07/15/2010 04:46 PM, Hans-Christoph Steiner wrote:
> > 
> > 
> > The vwait timeout would not be needed if we can rely on 'pd' to actually
> > fully die when it exits/crashes.  On Mac OS X at least it is often
> > doesn't completely crash and the process just sits there doing who knows
> > what.  If this happens on startup, pd-gui's exec call will not return,
> > and pdtk_pd_startup won't be called and pd-gui will just sit and wait
> > forever, giving us a zombie pd-gui.  The vwait stuff wouldn't be needed
> > if we can rely of pd to exit completely on all platforms.  Just removing
> > the vwait stuff is just replacing one problem with another.
> 
> sure.
> i'm only talking about the race-condition.
> whether the vwait is there for other things is entirely beyond my scope.
> 
> iirc, this is the title of this thread as well.
> 
> > Relax, no one is suggesting fixing a race condition with a timeout.  Can
> > you describe how to reproduce the race condition? What's actually
> > racing? Did Miller's changes fix it?
> 
> i did not experience any problem with miller's changes so far (which
> does not mean that the race-condition is gone, it just didn't show up)
> 
> racing was between pd-gui and pd: if the latter was to late, either
> pd-gui would timeout or the media menu would be initialized wrongly (no
> audio/midi APIs available)
> 
> leaving all this aside, i still think that it is a good idea for Pd to
> be able to change the dynamic entries of the menu at any time.
> if the available APIs change, Pd could update the menu accordingly
> (sounds like a stupid idea? but if jackd is running, then the only
> really available API would be jack (OSS, ALSA, portaudio being all
> blocked by jackd; ich jackd stops, other APIs would become available again)
> 
> gfmasdr
> IOhannes
> 



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