Thanks for your reply. On Thu, 2010-06-03 at 08:40 +0200, Clemens Ladisch wrote: > John Lindgren wrote: > > In a multi-threaded application it is possible for snd_pcm_delay or an > > equivalent function to be called by one thread while another is sitting > > in snd_pcm_writei. > > Alsa-lib is not thread safe. In theory, you are not even allowed to > call snd_pcm_delay while another function on the same PCM device has not > yet returned. >From http://alsa-project.org/main/index.php/Main_Page: ALSA has the following significant features: ... SMP and thread-safe design. So, that's a big lie? > ... > > On the application side, the playback time counter will be calculated > > during this time as 0.5 seconds written to ALSA > > This is wrong; as long as the write call has not returned, you do not > know how much has been written (and when an error occurs, writing can > stop before). > > To keep track of the actual amount of data written, use non-blocking > mode and in a loop, write as much as possible in one call, then update > your write counter, then wait for some more free space in the buffer > with poll(). Would it work to simply call snd_pcm_wait? John Lindgren _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
