[alsa-devel] Unblock MIDI IN in blocking read mode

Hi,

for best performance, I use a blocking snd_rawmidi_read() on an ALSA MIDI input device, byte by byte. It works fine, except:

1) How do I close the device from a different thread? I.e. how can I unblock the blocking read() call when it's time to close the device and no MIDI data is currently coming in? Just calling snd_rawmidi_close() will cause a crash. Using snd_rawmidi_drop() did not release the blocking read() in the other thread.

2) How is a blocking read() typically implemented in the ALSA MIDI driver? Maybe I can resort to non-blocking mode and avoid the situation above.

Thanks, Florian