The solution to our conundrum is to run more than one thread of execution at the same time. CPUs and modern operating systems are very good at dealing with multiple processes and multiple threads of execution within processes, and this suits our purposes nicely. What we really want is one task that is receiving callbacks from the controller and handling the input, with a separate task taking our control messages and outputting them. This would give us a robust setup in which we can easily do anything we want in the output thread, without introducing issues associated with blocking the input processing thread. We could be happily logging output to a file, sending it over a network, outputting MIDI to hardware, controlling GPIO pins, doing expensive calculations or 3D graphics, and not affect the response time of our Leap callbacks.
As with many things in software development, there is more than one way to achieve our desired result of multitasking: POSIX threading...
