Maarten Lankhorst schrieb: > Peter Beutner schreef: >> AFAIK you get the DRVM_EXIT message only when winmm is unloading. >> Alternatively you could do it in response to the DRV_CLOSE message which >> winmm >> sends just before it tries to unload the driver. >> >> That said I don't see how your code in ALSA_MixerExit() could deadlock. >> It effectively tries to exit the thread the same way as MIX_Close, doesn't >> it? >> So the thread should exit safely. >> Imo the question is rather why the thread isn't exiting and you are waiting >> forever. Forcibly calling TerminateThread just covers the problem > The deadlock isn't in the alsa code, it's in the kernel code: > Kernel holds thread lock and calls closing winmm code, closing code > closes mixer driver, mixer closing waits on thread, thread waits till it > can hold thread lock -> deadlock. > > Under normal circumstances, MIX_Open will be called as often as > MIX_Close is. If the programmer is lazy and never closes its handle, > MIX_Close will be called when winmm is shutting down, in that case I
Are you sure about this? I don't think winmm calls MIX_Close on its own when it shuts down and the device is still open. It only sends the DRVM_EXIT message(and throws out a FIXME). So there shouldn't be a deadlock in MIX_Close() and in ALSA_MixerExit() you can always call TerminateThread when the thread still exists.
