On Thu, Apr 11, 2002 at 06:23:13PM +0200, Takashi Iwai wrote: > int snd_pcm_async(snd_pcm_t *pcm, int sig, pid_t pid) > > .. so you can pass your favorite signal to the 2nd argument. > > or do i misunderstand your question?
Yes, let me try to explain it a bit better. BTW, This is for FreeSCI (http://freesci.linuxgames.com). The main process forks off a child to handle all of the sound-related stuff, and communicates with that child through a pair of pipes. We use select()s to check for events, usually with a very small (~100ms max) timeout. We need the timeout to enforce note timing. The child process is what opens the sound device. I wrote an ALSA PCM output plugin for FreeSCI which uses async PCM; ie I register a callback, and every period ALSA kicks in, executes the callback and fills its buffers. Both on their own work just fine. However, when I turn on the ALSA callback, the select()s block indefinately. Since the select()s block, no note data gets fired off, which results in no sound. I am not installing any SIGIO handler at all; The only ones installed in the child is SIGPIPE. I tried the snd_pcm_async() call; that didn't help. What happens is the callback keeps kitting my custom signal, but meanwhile the select()s still block. If I don't start the pcm device, then the select()s succeed. - Pizza -- Solomon Peachy pizzaATfucktheusers.org I ain't broke, but I'm badly bent. ICQ# 1318344 Patience comes to those who wait. ...It's not "Beanbag Love", it's a "Transanimate Relationship"...
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