[alsa-devel] snd_pcm_wait function

Clemens Ladisch clemens at ladisch.de
Sat Nov 10 18:20:12 CET 2012

Enno Fennema wrote:
> The documentation says this functions waits for the pcm to become ready for I/O.
> I am not sure what ready means in this context.

Ready for playback/capture, i.e., some frames are available.

> Is there a function to wait for entering the SETUP state. In particular I would
> like to wait for pcm_snd_drain to finish.

This is not possible.  alsa-lib is not thread-safe, so while another thread is
executing snd_pcm_drain, you cannot access the same PCM device.
Let the other thread send a message after snd_pcm_drain has finished.


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