This strays a bit beyond my functional knowledge of the details, I've monkied around a bit with the source but only in a few areas. But my understanding is that the 'main thread' is effectively is the game and runs the show. I don't think you can pause or sleep it. Well, you can, but that would quiting the the game, or backgrounding it. All game functions would stop. Basically you can do that now by quiting or switching apps on your phone.