def mainloop(self):
        """ The main loop.
        """
        self._validate_config()
        config.engine.load_config()

        # Defaults for process control paths
        if not self.options.no_fork and not self.options.guard_file:
            self.options.guard_file = os.path.join(config.config_dir, "run/pyrotorque")
        if not self.options.pid_file:
            self.options.pid_file = os.path.join(config.config_dir, "run/pyrotorque.pid")

        # Process control
        if self.options.status or self.options.stop or self.options.restart:
            if self.options.pid_file and os.path.exists(self.options.pid_file):
                running, pid = osmagic.check_process(self.options.pid_file)
            else:
                running, pid = False, 0

            if self.options.stop or self.options.restart:
                if running:
                    os.kill(pid, signal.SIGTERM)

                    # Wait for termination (max. 10 secs)
                    for _ in range(100):
                        running, _ = osmagic.check_process(self.options.pid_file)
                        if not running:
                            break
                        time.sleep(.1)

                    self.LOG.info("Process #%d stopped." % (pid))
                elif pid:
                    self.LOG.info("Process #%d NOT running anymore." % (pid))
                else:
                    self.LOG.info("No pid file '%s'" % (self.options.pid_file or "<N/A>"))
            else:
                self.LOG.info("Process #%d %s running." % (pid, "UP and" if running else "NOT"))

            if self.options.restart:
                if self.options.pid_file:
                    running, pid = osmagic.check_process(self.options.pid_file)
                    if running:
                        self.return_code = error.EX_TEMPFAIL
                        return
            else:
                self.return_code = error.EX_OK if running else error.EX_UNAVAILABLE
                return

        # Check for guard file and running daemon, abort if not OK
        try:
            osmagic.guard(self.options.pid_file, self.options.guard_file)
        except EnvironmentError as exc:
            self.LOG.debug(str(exc))
            self.return_code = error.EX_TEMPFAIL
            return

        # Detach, if not disabled via option
        if not self.options.no_fork: # or getattr(sys.stdin, "isatty", lambda: False)():
            osmagic.daemonize(pidfile=self.options.pid_file, logfile=logutil.get_logfile())
            time.sleep(.05) # let things settle a little
        signal.signal(signal.SIGTERM, _raise_interrupt)

        # Set up services
        from apscheduler.scheduler import Scheduler
        self.sched = Scheduler(config.torque)

        self._init_wsgi_server()

        # Run services
        self.sched.start()
        try:
            self._add_jobs()
            # TODO: daemonize here, or before the scheduler starts?
            self._run_forever()
        finally:
            self.sched.shutdown()
            if self.wsgi_server:
                self.wsgi_server.task_dispatcher.shutdown()
                self.wsgi_server = None

            if self.options.pid_file:
                try:
                    os.remove(self.options.pid_file)
                except EnvironmentError as exc:
                    self.LOG.warn("Failed to remove pid file '%s' (%s)" % (self.options.pid_file, exc))
                    self.return_code = error.EX_IOERR