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use crate::sync::Notify;
use loom::future::block_on;
use loom::sync::Arc;
use loom::thread;
use tokio_test::{assert_pending, assert_ready};
/// `util::wake_list::NUM_WAKERS`
const WAKE_LIST_SIZE: usize = 32;
#[test]
fn notify_one() {
loom::model(|| {
let tx = Arc::new(Notify::new());
let rx = tx.clone();
let th = thread::spawn(move || {
block_on(async {
rx.notified().await;
});
});
tx.notify_one();
th.join().unwrap();
});
}
#[test]
fn notify_waiters() {
loom::model(|| {
let notify = Arc::new(Notify::new());
let tx = notify.clone();
let notified1 = notify.notified();
let notified2 = notify.notified();
let th = thread::spawn(move || {
tx.notify_waiters();
});
block_on(async {
notified1.await;
notified2.await;
});
th.join().unwrap();
});
}
#[test]
fn notify_waiters_and_one() {
loom::model(|| {
let notify = Arc::new(Notify::new());
let tx1 = notify.clone();
let tx2 = notify.clone();
let th1 = thread::spawn(move || {
tx1.notify_waiters();
});
let th2 = thread::spawn(move || {
tx2.notify_one();
});
let th3 = thread::spawn(move || {
let notified = notify.notified();
block_on(async {
notified.await;
});
});
th1.join().unwrap();
th2.join().unwrap();
th3.join().unwrap();
});
}
#[test]
fn notify_multi() {
loom::model(|| {
let notify = Arc::new(Notify::new());
let mut ths = vec![];
for _ in 0..2 {
let notify = notify.clone();
ths.push(thread::spawn(move || {
block_on(async {
notify.notified().await;
notify.notify_one();
})
}));
}
notify.notify_one();
for th in ths.drain(..) {
th.join().unwrap();
}
block_on(async {
notify.notified().await;
});
});
}
#[test]
fn notify_drop() {
use crate::future::poll_fn;
use std::future::Future;
use std::task::Poll;
loom::model(|| {
let notify = Arc::new(Notify::new());
let rx1 = notify.clone();
let rx2 = notify.clone();
let th1 = thread::spawn(move || {
let mut recv = Box::pin(rx1.notified());
block_on(poll_fn(|cx| {
if recv.as_mut().poll(cx).is_ready() {
rx1.notify_one();
}
Poll::Ready(())
}));
});
let th2 = thread::spawn(move || {
block_on(async {
rx2.notified().await;
// Trigger second notification
rx2.notify_one();
rx2.notified().await;
});
});
notify.notify_one();
th1.join().unwrap();
th2.join().unwrap();
});
}
/// Polls two `Notified` futures and checks if poll results are consistent
/// with each other. If the first future is notified by a `notify_waiters`
/// call, then the second one must be notified as well.
#[test]
fn notify_waiters_poll_consistency() {
fn notify_waiters_poll_consistency_variant(poll_setting: [bool; 2]) {
let notify = Arc::new(Notify::new());
let mut notified = [
tokio_test::task::spawn(notify.notified()),
tokio_test::task::spawn(notify.notified()),
];
for i in 0..2 {
if poll_setting[i] {
assert_pending!(notified[i].poll());
}
}
let tx = notify.clone();
let th = thread::spawn(move || {
tx.notify_waiters();
});
let res1 = notified[0].poll();
let res2 = notified[1].poll();
// If res1 is ready, then res2 must also be ready.
assert!(res1.is_pending() || res2.is_ready());
th.join().unwrap();
}
// We test different scenarios in which pending futures had or had not
// been polled before the call to `notify_waiters`.
loom::model(|| notify_waiters_poll_consistency_variant([false, false]));
loom::model(|| notify_waiters_poll_consistency_variant([true, false]));
loom::model(|| notify_waiters_poll_consistency_variant([false, true]));
loom::model(|| notify_waiters_poll_consistency_variant([true, true]));
}
/// Polls two `Notified` futures and checks if poll results are consistent
/// with each other. If the first future is notified by a `notify_waiters`
/// call, then the second one must be notified as well.
///
/// Here we also add other `Notified` futures in between to force the two
/// tested futures to end up in different chunks.
#[test]
fn notify_waiters_poll_consistency_many() {
fn notify_waiters_poll_consistency_many_variant(order: [usize; 2]) {
let notify = Arc::new(Notify::new());
let mut futs = (0..WAKE_LIST_SIZE + 1)
.map(|_| tokio_test::task::spawn(notify.notified()))
.collect::<Vec<_>>();
assert_pending!(futs[order[0]].poll());
for i in 2..futs.len() {
assert_pending!(futs[i].poll());
}
assert_pending!(futs[order[1]].poll());
let tx = notify.clone();
let th = thread::spawn(move || {
tx.notify_waiters();
});
let res1 = futs[0].poll();
let res2 = futs[1].poll();
// If res1 is ready, then res2 must also be ready.
assert!(res1.is_pending() || res2.is_ready());
th.join().unwrap();
}
// We test different scenarios in which futures are polled in different order.
loom::model(|| notify_waiters_poll_consistency_many_variant([0, 1]));
loom::model(|| notify_waiters_poll_consistency_many_variant([1, 0]));
}
/// Checks if a call to `notify_waiters` is observed as atomic when combined
/// with a concurrent call to `notify_one`.
#[test]
fn notify_waiters_is_atomic() {
fn notify_waiters_is_atomic_variant(tested_fut_index: usize) {
let notify = Arc::new(Notify::new());
let mut futs = (0..WAKE_LIST_SIZE + 1)
.map(|_| tokio_test::task::spawn(notify.notified()))
.collect::<Vec<_>>();
for fut in &mut futs {
assert_pending!(fut.poll());
}
let tx = notify.clone();
let th = thread::spawn(move || {
tx.notify_waiters();
});
block_on(async {
// If awaiting one of the futures completes, then we should be
// able to assume that all pending futures are notified. Therefore
// a notification from a subsequent `notify_one` call should not
// be consumed by an old future.
futs.remove(tested_fut_index).await;
let mut new_fut = tokio_test::task::spawn(notify.notified());
assert_pending!(new_fut.poll());
notify.notify_one();
// `new_fut` must consume the notification from `notify_one`.
assert_ready!(new_fut.poll());
});
th.join().unwrap();
}
// We test different scenarios in which the tested future is at the beginning
// or at the end of the waiters queue used by `Notify`.
loom::model(|| notify_waiters_is_atomic_variant(0));
loom::model(|| notify_waiters_is_atomic_variant(32));
}
/// Checks if a single call to `notify_waiters` does not get through two `Notified`
/// futures created and awaited sequentially like this:
/// ```ignore
/// notify.notified().await;
/// notify.notified().await;
/// ```
#[test]
fn notify_waiters_sequential_notified_await() {
use crate::sync::oneshot;
loom::model(|| {
let notify = Arc::new(Notify::new());
let (tx_fst, rx_fst) = oneshot::channel();
let (tx_snd, rx_snd) = oneshot::channel();
let receiver = thread::spawn({
let notify = notify.clone();
move || {
block_on(async {
// Poll the first `Notified` to put it as the first waiter
// in the queue.
let mut first_notified = tokio_test::task::spawn(notify.notified());
assert_pending!(first_notified.poll());
// Create additional waiters to force `notify_waiters` to
// release the lock at least once.
let _task_pile = (0..WAKE_LIST_SIZE + 1)
.map(|_| {
let mut fut = tokio_test::task::spawn(notify.notified());
assert_pending!(fut.poll());
fut
})
.collect::<Vec<_>>();
// We are ready for the notify_waiters call.
tx_fst.send(()).unwrap();
first_notified.await;
// Poll the second `Notified` future to try to insert
// it to the waiters queue.
let mut second_notified = tokio_test::task::spawn(notify.notified());
assert_pending!(second_notified.poll());
// Wait for the `notify_waiters` to end and check if we
// are woken up.
rx_snd.await.unwrap();
assert_pending!(second_notified.poll());
});
}
});
// Wait for the signal and call `notify_waiters`.
block_on(rx_fst).unwrap();
notify.notify_waiters();
tx_snd.send(()).unwrap();
receiver.join().unwrap();
});
}