'Dispatches the given event to interested listeners.
:param SchedulerEvent event: the event to send'

def _dispatch_event(self, event):

    with self._listeners_lock:
        listeners = tuple(self._listeners)
    for (cb, mask) in listeners:
        if (event.code & mask):
            try:
                cb(event)
            except:
                self._logger.exception('Error    notifying    listener')
