Hi there, I've got a (hopefully quick) query about snd_config_update_free_global() and it's general thread safetyness. I'm currently going insane on this bug: https://bugs.kde.org/show_bug.cgi?id=232068 which revolves around a bug manifested in snd_pcm_close() (or rather snd_pcm_ioplug_close()) when dealing with the ALSA->PulseAudio plugin. >From what I can gather, this problem is related to a KDE module that is loaded into the library in question which does some alsa probing and ultimately calls snd_config_update_free_global() several times. The library itself then goes on to use GStreamer to do actual audio output. The crash then manifests itself prior to any sound actually being output. I can reliably reproduce the machine on two machines (I don't have many at my disposal), but cannot reproduce on a third. The two I can reproduce it on are two and four core intel duo's. The one I cannot reproduce on is an older, single core machine. I am leaning towards some kind of thread safety issue. In searching for similar problems, I found several references to similar crashes attributed to snd_dlobj_cache_cleanup() perhaps not being thread safe. e.g.: https://bugzilla.redhat.com/show_bug.cgi?id=482797#c14 and http://osdir.com/ml/attachments/txtpisfDmzbcN.txt (and from that: https://bugtrack.alsa-project.org/alsa-bug/view.php?id=2124 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=589896 ) I've found that removing the calls to snd_config_update_free_global() avoid the issue. I'm not even sure they are needed, but all the same I wanted to discuss the core issue. The MEMORY-LEAK file suggests that it should only be called after all snd_*_open() calls, but it doesn't indicate if this is just a recommendation or mandatory. Is the *only* purpose of this call to make valgrind happy? Or does it serve some other useful purpose too? Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mandriva Linux Contributor [http://www.mandriva.com/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/] _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
