vlovich/hidapi — comment on commit df439ca883c6fbd8488d6e5fa6a2467703ef5d9c
File:  line 0
By vlovich:

No, it shouldn't interfere with one that does have a run loop. 0.001 because it has to be the smallest unit of time that actually allows the system to process the events. I tried 0, but the latency was too big. Anything smaller than 0.001 seemed like it had the same impact as sending 0.

It doesn't call the main run loop - it calls the run loop for the current thread (which is actually perfectly safe to do according to Apple's documentation from my understanding).