[pulseaudio-discuss] Thread message queue crash

[David Henningsson]

On 09/23/2011 04:59 PM, Colin Guthrie wrote:
> 'Twas brillig, and Maarten Bosmans at 23/09/11 09:48 did gyre and gimble:
>> 2011/9/22 Colin Guthrie<gmane at colin.guthr.ie>:
>>> '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!
>>
>> And from the commit that introduced it, it looks like a type too.
>>
>> In 045c1d602dcba57868845ba3270510593c39480f merge glitch-free branch
>> back into trunk (damn you svn-merge commits)
>> pa_asyncmsgq_{before,after}_poll gets renamed to
>> pa_asyncmsgq_read_{before,after}_poll and
>> pa_asyncmsgq_write_{before,after}_poll is introduced. The conversion
>> was wrong there.
>
> Seems conclusive enough. Want to make that a proper patch David?

Ok, here you go!

-- 
David Henningsson, Canonical Ltd.
http://launchpad.net/~diwic