[pulseaudio-discuss] Thread message queue crash

[Colin Guthrie]

'Twas brillig, and David Henningsson at 25/09/11 10:15 did gyre and gimble:
> 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!

Thanks, pushed.

Col


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Colin Guthrie
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