def _background_loop(self):
        """Main background loop - waits for all clients to exit, then shuts down
        the current process."""
        with self.cond:
            while self.clients:
                self.cond.wait()
            # all clients have exited now, so shut down
            trigger_exit(ExitMode.PARENT)
Main background loop - waits for all clients to exit, then shuts down
        the current process.
fiftyone/service/main.py