On Tuesday 30 August 2016 15:20, Takashi Iwai wrote: > (Adding Alan to Cc) > > On Fri, 26 Aug 2016 21:02:12 +0200, > > Samuel Thibault wrote: > > Samuel Thibault, on Sat 20 Aug 2016 14:12:05 +0200, wrote: > > > I'd just like to check something: do we agree that libasound must be > > > thread-safe by default (otherwise it breaks the application assumption > > > that it's thread-safe)? If so, then there are thread-safety bugs: > > > > Ok, now with the discussion on the portaudio list starting at > > > > https://lists.columbia.edu/pipermail/portaudio/2016-August/000599.html > > > > it seems the issue was in portaudio, which was hit by the locking > > behavior change. > > Good to hear that it's been addressed in portaudio side. > > But I still wonder in which code path the deadlock was triggered. > Can anyone give the stack traces of deadlocked (multi-)threads? Actually, it wasn't so much the locking itself, but thread cancellation during one call (snd_pcm_mmap_commit()) leaving the lock held and not released, which then balked when a cleanup call to snd_pcm_drop() attempted to aquire the lock. This occurred as a result of an 'Abort' action in Portaudio. It can be avoided by disabling cancelablity at all times except when waiting on poll(), though I have yet to be completely satisfied there are no snags in this approach, as cancelability is new to me! Regards Alan _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
