Double buffering isn't very suitable for audio. You're right that a suitably-large buffer would allow non-realtime code to "render" e.g. a tenth of a second of

Double buffering isn't very suitable for audio. You're right that a suitably-large buffer would allow non-realtime code to "render" e.g. a tenth of a second of audio and pass it off to the realtime audio thread (and/or the audio subsystem, if that has sufficiently-large buffers on your platform). Unfortunately, such large buffers also introduces significant latency; the added latency is fine if you're a music player, but is pretty nasty for interactive applications.