[Jack-Devel] Volatile vs memory fences

I was reviewing the code for `jack_ringbuffer` and I saw it uses `volatile` for the pointers. This confused me, since my teachers have long insisted that `volatile` isn't for use on multithreaded code. Take i.e. `jack_ringbuffer_write`: the hardware could reorder the writes so that the pointer is updated before the buffer has been written. Wouldn't a memory fence be required? I appreciate your responses, I'm quite a noob when it comes to lock-free programming... Thank you, Xavi