let selecting_fut = selecting .do_selecting( &client_config, &test_socket_provider, &mut rng, &time, &mut stop_receiver, ) .fuse(); let time = &time; let wait_fut = async { // Wait some arbitrary amount of time to ensure `do_selecting` is waiting on a reply. // Note that this is fake time, not 30 actual seconds. time.wait_until(std::time::Duration::from_secs(30)).await; } .fuse(); pin_mut!(selecting_fut, wait_fut); let main_future = async { select! { _ = selecting_fut => unreachable!("should keep retransmitting DHCPDISCOVER forever"), () = wait_fut => (), } }; pin_mut!(main_future); run_with_accelerated_time(&mut executor, time, &mut main_future); stop_sender.unbounded_send(()).expect("sending stop signal should succeed"); let selecting_result = selecting_fut.now_or_never().expect( "selecting_fut should complete after single poll after stop signal has been sent", ); assert_matches!(selecting_result, Ok(SelectingOutcome::GracefulShutdown));