On 09/22/2011 03:35 PM, Colin Guthrie wrote: > 'Twas brillig, and David Henningsson at 22/09/11 12:41 did gyre and gimble: >> I'm trying to trace down a crash: >> >> https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/853560 >> https://launchpadlibrarian.net/80418699/ThreadStacktrace.txt >> >> I'm seeing that both threads call "pa_asyncq_write_after_poll" >> simultaneously on the same object, which is module-null-sink's >> thread_mq->outq. The outq writes in the thread and reads from the main >> thread. Therefore it seems like the main thread should not call >> write_after_poll. From what I can see, there almost seems to be a typo >> in asyncmsgq_read_cb (see suggested patch below). >> >> But since this is deep down, has been there for three years without >> causing trouble in the past (for what we know), I'd like a second >> opinion before actually applying this patch. I've just run a a quick >> test here and it didn't seem to break anything. > > As well as not breaking things, does it also fix the problem case? > > Just from the patch posted, it does indeed look like a typo to me! I assume this is some kind of once-in-a-million race, so it's hard to test it, but yes - it definitely blocks the path that leads to the bug (pa_asyncq_write_after_poll called by both threads). -- David Henningsson, Canonical Ltd. http://launchpad.net/~diwic
