1 files changed, 156 insertions, 0 deletions
diff --git a/third_party/rust/tokio/tests/sync_notify.rs b/third_party/rust/tokio/tests/sync_notify.rs
new file mode 100644
index 0000000000..5318d131cf
--- /dev/null
+++ b/third_party/rust/tokio/tests/sync_notify.rs
@@ -0,0 +1,156 @@
+#![warn(rust_2018_idioms)]
+#![cfg(feature = "sync")]
+
+#[cfg(target_arch = "wasm32")]
+use wasm_bindgen_test::wasm_bindgen_test as test;
+
+use tokio::sync::Notify;
+use tokio_test::task::spawn;
+use tokio_test::*;
+
+trait AssertSend: Send + Sync {}
+impl AssertSend for Notify {}
+
+#[test]
+fn notify_notified_one() {
+    let notify = Notify::new();
+    let mut notified = spawn(async { notify.notified().await });
+
+    notify.notify_one();
+    assert_ready!(notified.poll());
+}
+
+#[test]
+fn notified_one_notify() {
+    let notify = Notify::new();
+    let mut notified = spawn(async { notify.notified().await });
+
+    assert_pending!(notified.poll());
+
+    notify.notify_one();
+    assert!(notified.is_woken());
+    assert_ready!(notified.poll());
+}
+
+#[test]
+fn notified_multi_notify() {
+    let notify = Notify::new();
+    let mut notified1 = spawn(async { notify.notified().await });
+    let mut notified2 = spawn(async { notify.notified().await });
+
+    assert_pending!(notified1.poll());
+    assert_pending!(notified2.poll());
+
+    notify.notify_one();
+    assert!(notified1.is_woken());
+    assert!(!notified2.is_woken());
+
+    assert_ready!(notified1.poll());
+    assert_pending!(notified2.poll());
+}
+
+#[test]
+fn notify_notified_multi() {
+    let notify = Notify::new();
+
+    notify.notify_one();
+
+    let mut notified1 = spawn(async { notify.notified().await });
+    let mut notified2 = spawn(async { notify.notified().await });
+
+    assert_ready!(notified1.poll());
+    assert_pending!(notified2.poll());
+
+    notify.notify_one();
+
+    assert!(notified2.is_woken());
+    assert_ready!(notified2.poll());
+}
+
+#[test]
+fn notified_drop_notified_notify() {
+    let notify = Notify::new();
+    let mut notified1 = spawn(async { notify.notified().await });
+    let mut notified2 = spawn(async { notify.notified().await });
+
+    assert_pending!(notified1.poll());
+
+    drop(notified1);
+
+    assert_pending!(notified2.poll());
+
+    notify.notify_one();
+    assert!(notified2.is_woken());
+    assert_ready!(notified2.poll());
+}
+
+#[test]
+fn notified_multi_notify_drop_one() {
+    let notify = Notify::new();
+    let mut notified1 = spawn(async { notify.notified().await });
+    let mut notified2 = spawn(async { notify.notified().await });
+
+    assert_pending!(notified1.poll());
+    assert_pending!(notified2.poll());
+
+    notify.notify_one();
+
+    assert!(notified1.is_woken());
+    assert!(!notified2.is_woken());
+
+    drop(notified1);
+
+    assert!(notified2.is_woken());
+    assert_ready!(notified2.poll());
+}
+
+#[test]
+fn notify_in_drop_after_wake() {
+    use futures::task::ArcWake;
+    use std::future::Future;
+    use std::sync::Arc;
+
+    let notify = Arc::new(Notify::new());
+
+    struct NotifyOnDrop(Arc<Notify>);
+
+    impl ArcWake for NotifyOnDrop {
+        fn wake_by_ref(_arc_self: &Arc<Self>) {}
+    }
+
+    impl Drop for NotifyOnDrop {
+        fn drop(&mut self) {
+            self.0.notify_waiters();
+        }
+    }
+
+    let mut fut = Box::pin(async {
+        notify.notified().await;
+    });
+
+    {
+        let waker = futures::task::waker(Arc::new(NotifyOnDrop(notify.clone())));
+        let mut cx = std::task::Context::from_waker(&waker);
+        assert!(fut.as_mut().poll(&mut cx).is_pending());
+    }
+
+    // Now, notifying **should not** deadlock
+    notify.notify_waiters();
+}
+
+#[test]
+fn notify_one_after_dropped_all() {
+    let notify = Notify::new();
+    let mut notified1 = spawn(async { notify.notified().await });
+
+    assert_pending!(notified1.poll());
+
+    notify.notify_waiters();
+    notify.notify_one();
+
+    drop(notified1);
+
+    let mut notified2 = spawn(async { notify.notified().await });
+
+    assert_ready!(notified2.poll());
+}