>maybe i'm missing something somewhere, but is there a reason why i can't >seem to get audio processing via async handlers to work reliably?
i have explained before on the alsa-devel list that the async handling stuff in ALSA is fundamentally incompatible with POSIX. you are not allowed to do very much from a signal handler, and you run into several subtle scheduling issues with the kernel that do not exist for "synchronous" I/O. its hard to say more without seeing what you code actually does. >i'm using andrew morton's kernel patch for 2.4.18.....and i can crank the >latency test program all the way down to 64 frames with no trouble. but >when i try to do things with async handlers, i get underruns from typing >in xterms or things simpler than that > >i can rewrite my code to work without callbacks without much effort..but >i'm confused as to why this might happen, considering that blocking >through snd_pcm_wait() shouldn't be that much different as far as process >wakeup time the difference is that your async code is executing c/o the kernel's signal handling system, and not in a regular execution context. you're running on a different stack, for a start. you'd be much better off (and have no more "issues") starting a thread and using poll(2). --p
