How to use the scs.signals.controller_ready function in scs

def prepare_signals(self):
        signals.controller_ready.connect(self._component_ready)
        signals.httpd_ready.connect(self._component_ready)
        signals.supervisor_ready.connect(self._component_ready)
        signals.agent_ready.connect(self.on_ready)

self.connection = celery.broker_connection()
        self.without_httpd = without_httpd
        self.logfile = logfile
        self.loglevel = loglevel
        self.numc = numc
        self.ready_event = ready_event
        self.exit_request = Event()
        if not self.without_httpd:
            self.httpd = gSup(instantiate(self.httpd_cls, addrport),
                              signals.httpd_ready)
        self.supervisor = gSup(instantiate(self.supervisor_cls, sup_interval),
                               signals.supervisor_ready)
        self.controllers = [gSup(instantiate(self.controller_cls,
                                   id="%s.%s" % (self.id, i),
                                   connection=self.connection),
                                 signals.controller_ready)
                                for i in xrange(1, numc + 1)]
        c = [self.supervisor] + self.controllers + [self.httpd]
        c = self.components = list(filter(None, c))
        self._components_ready = dict(zip([z.thread for z in c],
                                          [False] * len(c)))
        super(Agent, self).__init__()

def on_consume_ready(self):
        if not self._ready_sent:
            controller_ready.send(sender=self)
            self._ready_sent = True
        super(Controller, self).on_consume_ready()