use qubit_clock::{
StdMonotonicClock,
StdTimer,
Timer,
};
use std::sync::{
Arc,
atomic::{
AtomicUsize,
Ordering,
},
};
use std::task::{
Context,
Poll,
Wake,
Waker,
};
use std::time::Duration;
#[derive(Default)]
struct WakeCounter(AtomicUsize);
impl Wake for WakeCounter {
fn wake(self: Arc<Self>) {
self.0.fetch_add(1, Ordering::Relaxed);
}
}
#[test]
fn test_std_timer_waiter_state_replaces_registered_waker() {
let clock = StdMonotonicClock::new();
let timer = StdTimer::from_clock(&clock);
let mut future = timer
.after(Duration::from_millis(10))
.expect("short deadline should register");
let first_counter = Arc::new(WakeCounter::default());
let second_counter = Arc::new(WakeCounter::default());
let first_waker = Waker::from(Arc::clone(&first_counter));
let second_waker = Waker::from(Arc::clone(&second_counter));
let mut first_context = Context::from_waker(&first_waker);
let mut second_context = Context::from_waker(&second_waker);
assert!(future.as_mut().poll(&mut first_context).is_pending());
assert!(future.as_mut().poll(&mut second_context).is_pending());
std::thread::sleep(Duration::from_millis(30));
assert_eq!(0, first_counter.0.load(Ordering::Relaxed));
assert_eq!(1, second_counter.0.load(Ordering::Relaxed));
assert!(matches!(
future.as_mut().poll(&mut second_context),
Poll::Ready(Ok(()))
));
}