def shutdown(self):
        """Shuts down all components.  This should be called when the program
        exits so that components can do any necessary clean-up."""
        # Stop all components first
        self.stop()
        for component in self.components.keys():
            log.debug("Shutting down component %s..", component)
            try:
                if self.components[component].get_state() != COMPONENT_STATE.index("Stopped"):
                    self.components[component].shutdown()
            except Exception, e:
                log.debug("Unable to call shutdown(): %s", e)