def configure(protocol, port, pipes, interface):
  remove_all()
  reactor.addSystemEventTrigger('after', 'shutdown', remove_all)

  # gets default (outward-facing) network interface (e.g. deciding which of
  # eth0, eth1, wlan0 is being used by the system to connect to the internet)
  if interface == "auto":
    interface = netifaces.gateways()['default'][netifaces.AF_INET][1]
  else:
    if interface not in netifaces.interfaces():
      raise ValueError("Given interface does not exist.", interface)

  add(protocol, port, interface)
  manager = libnetfilter_queue.Manager()

  manager.bind(UP_QUEUE, packet_handler(manager, pipes.up))
  manager.bind(DOWN_QUEUE, packet_handler(manager, pipes.down))

  reader = abstract.FileDescriptor()
  reader.doRead = manager.process
  reader.fileno = lambda: manager.fileno
  reactor.addReader(reader) 

def __init__(self, stealStdio=True, printToConsole=True):
        '''
        The one big thing this function leaves out is reactor.start(). Call this externally
        *after * initializing a nexus object.
        '''
        self.session = None
        self.wamp_connected = False
        self.jwt_valid = False

        self.info = AttrWrapper()
        resolveInfo(self, settings.CONFIG_FILE)
        self.info.setOnChange(self.onInfoChange)

        # initialize output. If filepath is set, logs to file.
        # If stealStdio is set intercepts all stderr and stdout and interprets it internally
        # If printToConsole is set (defaults True) all final output is rendered to stdout
        output.out.startLogging(filePath=settings.LOG_DIR, stealStdio=stealStdio, printToConsole=printToConsole)

        # register onStop for the shutdown call
        reactor.addSystemEventTrigger('before', 'shutdown', self.onStop)

        # The reactor needs to be runnnig before this call is fired, since we start the session
        # here. Assuming callLater doesn't fire until thats happened
        reactor.callLater(0, self.onStart) 

def run():

    config.read()
    logs.api()

    top_service = service.MultiService()

    db = Db()
    datalib.db = db
    db.setServiceParent(top_service)

    http_service = internet.TCPServer(config.HTTP_PORT, Site(db), interface=config.HTTP_ADDR)
    http_service.setServiceParent(top_service)

    top_service.startService()

    reactor.addSystemEventTrigger('before', 'shutdown', top_service.stopService)

    reactor.run() 

def main(number):

    def get_metrics():
        return [
            ("checker.time.%s.%s" %
             (config.HOSTNAME,
              number),
                spy.TRIGGER_CHECK.get_metrics()["sum"]),
            ("checker.triggers.%s.%s" %
             (config.HOSTNAME,
              number),
                spy.TRIGGER_CHECK.get_metrics()["count"]),
            ("checker.errors.%s.%s" %
             (config.HOSTNAME,
              number),
                spy.TRIGGER_CHECK_ERRORS.get_metrics()["count"])]

    graphite.sending(get_metrics)

    def start(db):
        checker = TriggersCheck(db)
        checker.start()
        reactor.addSystemEventTrigger('before', 'shutdown', checker.stop)

    run(start) 

def run():

    config.read()
    logs.checker_master()

    if config.ARGS.t:
        check(config.ARGS.t)
        return

    top_service = TopService()

    db = Db()
    datalib.db = db
    db.setServiceParent(top_service)

    sub_service = MasterService(db)
    sub_service.setServiceParent(top_service)

    top_service.startService()

    reactor.addSystemEventTrigger('before', 'shutdown', top_service.stopService)

    reactor.run() 

def connect_with_retry(self):
        try:
            self.client.connect(self.broker_host, port=self.broker_port, keepalive=60)
            self.connect_loop.stop()
        except:
            log.failure(u'Error connecting to MQTT broker but retrying each {retry_interval} seconds',
                retry_interval=self.retry_interval)
            return

        """
        This is part of the threaded client interface. Call this once to
        start a new thread to process network traffic. This provides an
        alternative to repeatedly calling loop() yourself.
        """
        self.client.loop_start()
        reactor.addSystemEventTrigger('before', 'shutdown', self.client.loop_stop, True)

    # The callback for when the client receives a CONNACK response from the server. 

def test_singleStopErrback(self):
        """
        L{task.react} doesn't try to stop the reactor if the L{defer.Deferred}
        the function it is passed is errbacked after the reactor has already
        been stopped.
        """
        class ExpectedException(Exception):
            pass

        def main(reactor):
            reactor.callLater(1, reactor.stop)
            finished = defer.Deferred()
            reactor.addSystemEventTrigger(
                'during', 'shutdown', finished.errback, ExpectedException())
            return finished
        r = _FakeReactor()
        exitError = self.assertRaises(
            SystemExit, task.react, main, _reactor=r)

        self.assertEqual(1, exitError.code)

        self.assertEqual(r.seconds(), 1)
        errors = self.flushLoggedErrors(ExpectedException)
        self.assertEqual(len(errors), 1) 

def test_beforePreceedsDuring(self):
        """
        L{IReactorCore.addSystemEventTrigger} should call triggers added to the
        C{'before'} phase before it calls triggers added to the C{'during'}
        phase.
        """
        eventType = 'test'
        events = []
        def beforeTrigger():
            events.append('before')
        def duringTrigger():
            events.append('during')
        self.addTrigger('before', eventType, beforeTrigger)
        self.addTrigger('during', eventType, duringTrigger)
        self.assertEqual(events, [])
        reactor.fireSystemEvent(eventType)
        self.assertEqual(events, ['before', 'during']) 

def test_duringPreceedsAfter(self):
        """
        L{IReactorCore.addSystemEventTrigger} should call triggers added to the
        C{'during'} phase before it calls triggers added to the C{'after'}
        phase.
        """
        eventType = 'test'
        events = []
        def duringTrigger():
            events.append('during')
        def afterTrigger():
            events.append('after')
        self.addTrigger('during', eventType, duringTrigger)
        self.addTrigger('after', eventType, afterTrigger)
        self.assertEqual(events, [])
        reactor.fireSystemEvent(eventType)
        self.assertEqual(events, ['during', 'after']) 

def test_removeNonExistentSystemEventTrigger(self):
        """
        Passing an object to L{IReactorCore.removeSystemEventTrigger} which was
        not returned by a previous call to
        L{IReactorCore.addSystemEventTrigger} or which has already been passed
        to C{removeSystemEventTrigger} should result in L{TypeError},
        L{KeyError}, or L{ValueError} being raised.
        """
        b = self.addTrigger('during', 'test', lambda: None)
        self.removeTrigger(b)
        self.assertRaises(
            TypeError, reactor.removeSystemEventTrigger, None)
        self.assertRaises(
            ValueError, reactor.removeSystemEventTrigger, b)
        self.assertRaises(
            KeyError,
            reactor.removeSystemEventTrigger,
            (b[0], ('xxx',) + b[1][1:])) 

def start(self, stop_after_crawl=True):
        """
        This method starts a Twisted `reactor`_, adjusts its pool size to
        :setting:`REACTOR_THREADPOOL_MAXSIZE`, and installs a DNS cache based
        on :setting:`DNSCACHE_ENABLED` and :setting:`DNSCACHE_SIZE`.

        If ``stop_after_crawl`` is True, the reactor will be stopped after all
        crawlers have finished, using :meth:`join`.

        :param boolean stop_after_crawl: stop or not the reactor when all
            crawlers have finished
        """
        if stop_after_crawl:
            d = self.join()
            # Don't start the reactor if the deferreds are already fired
            if d.called:
                return
            d.addBoth(self._stop_reactor)

        reactor.installResolver(self._get_dns_resolver())
        tp = reactor.getThreadPool()
        tp.adjustPoolsize(maxthreads=self.settings.getint('REACTOR_THREADPOOL_MAXSIZE'))
        reactor.addSystemEventTrigger('before', 'shutdown', self.stop)
        reactor.run(installSignalHandlers=False)  # blocking call 

def test_singleStopCallback(self):
        """
        L{task.react} doesn't try to stop the reactor if the L{defer.Deferred}
        the function it is passed is called back after the reactor has already
        been stopped.
        """
        def main(reactor):
            reactor.callLater(1, reactor.stop)
            finished = defer.Deferred()
            reactor.addSystemEventTrigger(
                'during', 'shutdown', finished.callback, None)
            return finished
        r = _FakeReactor()
        exitError = self.assertRaises(
            SystemExit, task.react, main, _reactor=r)
        self.assertEqual(r.seconds(), 1)

        self.assertEqual(0, exitError.code) 

def test_singleStopErrback(self):
        """
        L{task.react} doesn't try to stop the reactor if the L{defer.Deferred}
        the function it is passed is errbacked after the reactor has already
        been stopped.
        """
        class ExpectedException(Exception):
            pass

        def main(reactor):
            reactor.callLater(1, reactor.stop)
            finished = defer.Deferred()
            reactor.addSystemEventTrigger(
                'during', 'shutdown', finished.errback, ExpectedException())
            return finished
        r = _FakeReactor()
        exitError = self.assertRaises(
            SystemExit, task.react, main, _reactor=r)

        self.assertEqual(1, exitError.code)

        self.assertEqual(r.seconds(), 1)
        errors = self.flushLoggedErrors(ExpectedException)
        self.assertEqual(len(errors), 1) 

def test_beforePreceedsDuring(self):
        """
        L{IReactorCore.addSystemEventTrigger} should call triggers added to the
        C{'before'} phase before it calls triggers added to the C{'during'}
        phase.
        """
        eventType = 'test'
        events = []
        def beforeTrigger():
            events.append('before')
        def duringTrigger():
            events.append('during')
        self.addTrigger('before', eventType, beforeTrigger)
        self.addTrigger('during', eventType, duringTrigger)
        self.assertEqual(events, [])
        reactor.fireSystemEvent(eventType)
        self.assertEqual(events, ['before', 'during']) 

def test_duringPreceedsAfter(self):
        """
        L{IReactorCore.addSystemEventTrigger} should call triggers added to the
        C{'during'} phase before it calls triggers added to the C{'after'}
        phase.
        """
        eventType = 'test'
        events = []
        def duringTrigger():
            events.append('during')
        def afterTrigger():
            events.append('after')
        self.addTrigger('during', eventType, duringTrigger)
        self.addTrigger('after', eventType, afterTrigger)
        self.assertEqual(events, [])
        reactor.fireSystemEvent(eventType)
        self.assertEqual(events, ['during', 'after']) 

def test_removeNonExistentSystemEventTrigger(self):
        """
        Passing an object to L{IReactorCore.removeSystemEventTrigger} which was
        not returned by a previous call to
        L{IReactorCore.addSystemEventTrigger} or which has already been passed
        to C{removeSystemEventTrigger} should result in L{TypeError},
        L{KeyError}, or L{ValueError} being raised.
        """
        b = self.addTrigger('during', 'test', lambda: None)
        self.removeTrigger(b)
        self.assertRaises(
            TypeError, reactor.removeSystemEventTrigger, None)
        self.assertRaises(
            ValueError, reactor.removeSystemEventTrigger, b)
        self.assertRaises(
            KeyError,
            reactor.removeSystemEventTrigger,
            (b[0], ('xxx',) + b[1][1:])) 

def __new__(cls, *args, **kw):
        if not hasattr(cls, '_instance'):
            instance = super(Controller, cls).__new__(cls)
            instance._allocated_pins = {}
            instance._poll_queue = select.epoll()

            instance._available_pins = []
            instance._running = True

            # Cleanup before stopping reactor
            reactor.addSystemEventTrigger('before', 'shutdown', instance.stop)

            # Run the EPoll in a Thread, as it blocks.
            reactor.callInThread(instance._poll_queue_loop)

            cls._instance = instance
        return cls._instance 

def test_beforePreceedsDuring(self):
        """
        L{IReactorCore.addSystemEventTrigger} should call triggers added to the
        C{'before'} phase before it calls triggers added to the C{'during'}
        phase.
        """
        eventType = 'test'
        events = []
        def beforeTrigger():
            events.append('before')
        def duringTrigger():
            events.append('during')
        self.addTrigger('before', eventType, beforeTrigger)
        self.addTrigger('during', eventType, duringTrigger)
        self.assertEqual(events, [])
        reactor.fireSystemEvent(eventType)
        self.assertEqual(events, ['before', 'during']) 

def test_duringPreceedsAfter(self):
        """
        L{IReactorCore.addSystemEventTrigger} should call triggers added to the
        C{'during'} phase before it calls triggers added to the C{'after'}
        phase.
        """
        eventType = 'test'
        events = []
        def duringTrigger():
            events.append('during')
        def afterTrigger():
            events.append('after')
        self.addTrigger('during', eventType, duringTrigger)
        self.addTrigger('after', eventType, afterTrigger)
        self.assertEqual(events, [])
        reactor.fireSystemEvent(eventType)
        self.assertEqual(events, ['during', 'after']) 

def run(self, save=1, installSignalHandlers=1):
        """run(save=1, installSignalHandlers=1)
        Run this application, running the main loop if necessary.
        If 'save' is true, then when this Application is shut down, it
        will be persisted to a pickle.
        'installSignalHandlers' is passed through to reactor.run(), the
        function that starts the mainloop.
        """
        from twisted.internet import reactor
        if not self._boundPorts:
            self.bindPorts()
        self._save = save
        reactor.addSystemEventTrigger('before', 'shutdown', self._beforeShutDown)
        reactor.addSystemEventTrigger('after', 'shutdown', self._afterShutDown)
        global theApplication
        theApplication = self
        log.callWithLogger(self, reactor.run, installSignalHandlers=installSignalHandlers)


#
# These are dummy classes for backwards-compatibility!
# 

def listen(configManager):
    # Things get messy if pdconfd is restarted with running chutes.  Then it
    # will try to reconfigure the system.  One easy solution is to unload the
    # configuration before exiting.
    reactor.addSystemEventTrigger('before', 'shutdown',
                                  configManager.unload)

    # Now load all of the configuration for the first time.
    configManager.loadConfig() 

def run(self, handler):
        from twisted.web import server, wsgi
        from twisted.python.threadpool import ThreadPool
        from twisted.internet import reactor
        thread_pool = ThreadPool()
        thread_pool.start()
        reactor.addSystemEventTrigger('after', 'shutdown', thread_pool.stop)
        factory = server.Site(wsgi.WSGIResource(reactor, thread_pool, handler))
        reactor.listenTCP(self.port, factory, interface=self.host)
        reactor.run() 

def run(self, handler):
        from twisted.web import server, wsgi
        from twisted.python.threadpool import ThreadPool
        from twisted.internet import reactor
        thread_pool = ThreadPool()
        thread_pool.start()
        reactor.addSystemEventTrigger('after', 'shutdown', thread_pool.stop)
        factory = server.Site(wsgi.WSGIResource(reactor, thread_pool, handler))
        reactor.listenTCP(self.port, factory, interface=self.host)
        reactor.run() 

def run(self, handler):
        from twisted.web import server, wsgi
        from twisted.python.threadpool import ThreadPool
        from twisted.internet import reactor
        thread_pool = ThreadPool()
        thread_pool.start()
        reactor.addSystemEventTrigger('after', 'shutdown', thread_pool.stop)
        factory = server.Site(wsgi.WSGIResource(reactor, thread_pool, handler))
        reactor.listenTCP(self.port, factory, interface=self.host)
        reactor.run() 

def __init__(self, host='localhost', port=50090, user=None, password=None, callbacks=None):
        """Initialize Monitor:
          connection parameters: host, port, user, password, 
          callbacks: {'name':function ...}  
            where name is one of ['status', 'error', 'time', 'order', 'execution', 'quote', 'trade', 'tick', 'shutdown']
            and function(data) is the callback that will receive event data
            callbacks must return True to continue monitor.run() loop
        """
        self.host = host
        self.port = port
        self.user = user
        self.password = password
        self.shutdown_pending = False
        self.channel = ''
        self.callback_types = ['status', 'error', 'time', 'order', 'execution', 'quote', 'trade', 'tick', 'shutdown']
        self.flags = 'noquotes notrades'
        self.connection = None

        if callbacks:
            self.callbacks = callbacks
        else:
            self.callbacks = {}
            for cb_type in self.callback_types:
                self.set_callback(cb_type, self._cb_print)

    	reactor.addSystemEventTrigger('before','shutdown', self.shutdown_event) 

def run(self, handler):
        from twisted.web import server, wsgi
        from twisted.python.threadpool import ThreadPool
        from twisted.internet import reactor
        thread_pool = ThreadPool()
        thread_pool.start()
        reactor.addSystemEventTrigger('after', 'shutdown', thread_pool.stop)
        factory = server.Site(wsgi.WSGIResource(reactor, thread_pool, handler))
        reactor.listenTCP(self.port, factory, interface=self.host)
        if not reactor.running:
            reactor.run() 

def opt_wsgi(self, name):
        """
        The FQPN of a WSGI application object to serve as the root resource of
        the webserver.
        """
        try:
            application = reflect.namedAny(name)
        except (AttributeError, ValueError):
            raise usage.UsageError("No such WSGI application: %r" % (name,))
        pool = threadpool.ThreadPool()
        reactor.callWhenRunning(pool.start)
        reactor.addSystemEventTrigger('after', 'shutdown', pool.stop)
        self['root'] = wsgi.WSGIResource(reactor, pool, application) 

def startApplication(application, save):
    from twisted.internet import reactor
    service.IService(application).startService()
    if save:
        p = sob.IPersistable(application)
        reactor.addSystemEventTrigger('after', 'shutdown', p.save, 'shutdown')
    reactor.addSystemEventTrigger('before', 'shutdown',
                                  service.IService(application).stopService) 

def _bail(self):
        from twisted.internet import reactor
        d = defer.Deferred()
        reactor.addSystemEventTrigger('after', 'shutdown',
                                      lambda: d.callback(None))
        reactor.fireSystemEvent('shutdown') # radix's suggestion
        # As long as TestCase does crap stuff with the reactor we need to
        # manually shutdown the reactor here, and that requires util.wait
        # :(
        # so that the shutdown event completes
        unittest.TestCase('mktemp')._wait(d) 

def onConnect():
#    if keyAgent and options['agent']:
#        cc = protocol.ClientCreator(reactor, SSHAgentForwardingLocal, conn)
#        cc.connectUNIX(os.environ['SSH_AUTH_SOCK'])
    if hasattr(conn.transport, 'sendIgnore'):
        _KeepAlive(conn)
    if options.localForwards:
        for localPort, hostport in options.localForwards:
            s = reactor.listenTCP(localPort,
                        forwarding.SSHListenForwardingFactory(conn,
                            hostport,
                            SSHListenClientForwardingChannel))
            conn.localForwards.append(s)
    if options.remoteForwards:
        for remotePort, hostport in options.remoteForwards:
            log.msg('asking for remote forwarding for %s:%s' %
                    (remotePort, hostport))
            conn.requestRemoteForwarding(remotePort, hostport)
        reactor.addSystemEventTrigger('before', 'shutdown', beforeShutdown)
    if not options['noshell'] or options['agent']:
        conn.openChannel(SSHSession())
    if options['fork']:
        if os.fork():
            os._exit(0)
        os.setsid()
        for i in range(3):
            try:
                os.close(i)
            except OSError as e:
                import errno
                if e.errno != errno.EBADF:
                    raise