We don't nee CFRunLoopWakeUp as at this time are currently running in an observer callback, and after running all of the BeforeWaiting observers it must surely check for more sources / etc to run before determining if it will sleep
It is not guaranteed that the runloop will turn if it has no scheduled work, and this causes processing of the queue to stop. Attaching a custom loop source to the run loop and signal it if new work needs to be done
