def start(self):
        """Start our callback in its own background thread."""
        if self.frequency > 0:
            threadname = self.name or self.__class__.__name__
            if self.thread is None:
                self.thread = BackgroundTask(
                    self.frequency,
                    self.callback,
                    bus=self.bus,
                )
                self.thread.name = threadname
                self.thread.start()
                self.bus.log('Started monitor thread %r.' % threadname)
            else:
                self.bus.log('Monitor thread %r already started.' % threadname)
Start our callback in its own background thread.
cherrypy/process/plugins.py