def start(self):
        """
        
        """
        self._process = self._launch_process(self._dag_directory,
                                             self._file_paths,
                                             self._max_runs,
                                             self._processor_factory,
                                             self._child_signal_conn,
                                             self._stat_queue,
                                             self._result_queue,
                                             self._async_mode)
        self.log.info("Launched DagFileProcessorManager with pid: %s", self._process.pid)