[MPlayer-users] [Bug report] Interrupting xvmc playback may result in deadlock.

[Thomas Hellström]

Version:
SVN as of today.
Summary:
When used with certain XvMC libraries that use non-recursive pthread 
mutexes to protect data in multithreaded environments, a deadlock can 
occur when mplayer exits as the result of a terminating signal.
What happens is that the mutex may be held by the main thread, when 
mplayer as part of the signal handler calls the xvmc uninit function. 
This function calls the XvMC library recursively, trying to lock the 
mutex again, and this results in a deadlock.
XvMC libraries are not guaranteed to be reentrant.
Fix:
I have attached an extremely ugly workaround that sets a global variable 
to indicate when execution is part of a signal handler. In that case, 
the XvMC library is never called. We can do this because when mplayer 
exits, the X server will do all necessary XvMC cleanup. Note: This patch 
is just to illustrate the problem. It's possible that gmplayer needs 
fixing too, and it's also possible that there is a much cleaner solution.

/Thomas


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