On Mon, 25 May 2009, Werner Van Belle wrote: > Jaroslav Kysela wrote: >> The question is if it's not better to free also allocated memory >> associated to the pcm handle in child process - so snd_pcm_close() >> call in child is not a bad idea. >> > Okay, while you both have been discussing some internals, which I didn't > try yet, I created a demonstration program to illustrate the mixed > semantics of the 'sharing' versus 'not sharing' behavior of the dsp > devices. In the example the parent thread will play a sound, then the > child closes the dsp, which affects the playback in the parent (it > either hangs or skips all remaining samples). From this one would > conclude that the pcm device is fully shared between the two processes > (semantics I can live with). However, when the parent then tries to > reopen the device it cannot do so because the device is still 'busy'. Your example program does not contain dsp_close() call in parent before dsp_open(). That's reason why PCM device is blocked. Jaroslav ----- Jaroslav Kysela <perex@xxxxxxxx> Linux Kernel Sound Maintainer ALSA Project, Red Hat, Inc. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
