Comment 7 for bug 1558791

not sure if it's worth implementing process instead of threads. i do recall it being more heavyweight than threads and meant more for longer running actions (not millisecond stuff we're doing). it also requires you to make everything serialisable so it may be non-trivial fix.

the only real alternative i found was using cython to turn off gil, but it's also a pretty big change.

http://docs.cython.org/src/userguide/parallelism.html