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

Colin Guthrie gmane at colin.guthr.ie
Sat Feb 28 18:27:35 PST 2009


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:

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.



Colin Guthrie

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