[linux-audio-dev] mutex in process callback?

Hi LADs, here is a problem that maybe very common with many rt audio apps, so hopefully there is a "standard" solution for it? assume jack process callback reads audio data from a buffer, while another thread might alter the contents of this buffer. In my particular scenario, i will actualy use doublebuffering. So the only operation that needs to be "mutexed" is the actual swapping of front and back buffers (well, pointers, of course, not the contents) Now my problem is: How can i make sure that swapping does not accure during process (playback) callback? I could use a mutex, but this might also block the playback thread. (if swapping is in process when the jack callback is invoked) On the other hand, swapping pointers shouldn't take that long, so maybe this would not be a problem? Or would it make sense to try and "foresee" such a situation and avoid it by delaying the swapping? Any clever suggestions on this? Regards, Lukas