def start(self):
        """Start the app for the engines subcommand."""
        self.log.info("IPython cluster: started")
        # First see if the cluster is already running
        
        # Now log and daemonize
        self.log.info(
            'Starting engines with [daemon=%r]' % self.daemonize
        )
        # TODO: Get daemonize working on Windows or as a Windows Server.
        if self.daemonize:
            if os.name=='posix':
                daemonize()

        dc = ioloop.DelayedCallback(self.start_engines, 0, self.loop)
        dc.start()
        # Now write the new pid file AFTER our new forked pid is active.
        # self.write_pid_file()
        try:
            self.loop.start()
        except __HOLE__:
            pass
        except zmq.ZMQError as e:
            if e.errno == errno.EINTR:
                pass
            else:
                raise
dataset/ETHPy150Open ipython/ipython-py3k/IPython/parallel/apps/ipclusterapp.py/IPClusterEngines.start