[alsa-devel] pcm write from posix threads

When calling snd_pcm_write* from a thread how do you safely cancel the thread? I've tried masking the signals which are used in alsa lib, yet I am getting a segfault on pthread_exit(). My thread is looping doing the following.

testcancel snd_pcm_wait snd_pcm_avail snd_pcm_writei

I am checking return values to handle those functions being woken up by pthread cancel and attempting to exit. In testing the process it performs fine until I start actually writing data. Once I write some data, a pthread_exit will segfault. My cancellation routine is calling snd_pcm_drop, then doing a cancel followed by join.