Adds a delegate to be called on each loop iteration, called based on the timingFlags.
Runs the event loop for this thread until the until delegate returns true.
Runs a single iteration of the event loop for this thread. It will return when the first thing happens, but that thing might be totally uninteresting to anyone, or it might trigger significant work you'll wait on.
Returns details from a call to runOnce. Use the named methods here for details, or it can be used in a while loop directly thanks to its opCast automatic conversion to bool.