Spin up the multiprocess event returner

def run(self):
        '''
        Spin up the multiprocess event returner
        '''
        salt.utils.process.appendproctitle(self.__class__.__name__)
        self.event = get_event('master', opts=self.opts, listen=True)
        events = self.event.iter_events(full=True)
        self.event.fire_event({}, 'salt/event_listen/start')
        try:
            for event in events:
                if event['tag'] == 'salt/event/exit':
                    self.stop = True
                if self._filter(event):
                    self.event_queue.append(event)
                if len(self.event_queue) >= self.event_return_queue:
                    self.flush_events()
                if self.stop:
                    break
        finally:  # flush all we have at this moment
            if self.event_queue:
                self.flush_events()