[pulseaudio-discuss] Threaded loops and theoretical deadlock in reference implementation (and lots of code).

[Colin Guthrie]

Hi,

I was trying to debug a deadlock while using gvim (with 
libcanberra+pulse output: https://qa.mandriva.com/show_bug.cgi?id=44925) 
I had reason to read the threaded loop docs.

The reference implementation shown here:
http://0pointer.de/lennart/projects/pulseaudio/doxygen/threaded_mainloop.html#basic_subsec

In my mind, the operation could theoretically be cancelled and this the 
_get_state() will return PA_OPERATION_CANCELLED.

In the example code, if this happens, the loop will spin and the main 
loop will never be unlocked.

This could be fixed by spinning when the state is PA_OPERATION_RUNNING 
rather when it is not PA_OPERATION_DONE (incidentally, there is a typo 
in the docs... it says OPERATION_RUNNING without the PA_ prefix...).

Anyway, any comments on this observation would be appreciated.

Col



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Colin Guthrie
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http://colin.guthr.ie/

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