code: def _run_once(self):
      
      try:
        self.do_wait()
        self._execute_wakeup_tasks()
        self._trigger_timers()
      except Exception as e:
        Log.error("Error occured during _run_once(): " + str(e))
        Log.error(traceback.format_exc())
        self.should_exit = True
docs: Run once, should be called only from loop()