1 files changed, 61 insertions, 0 deletions
diff --git a/tests/ui/async-await/futures-api.rs b/tests/ui/async-await/futures-api.rs
new file mode 100644
index 00000000000..a7da058de30
--- /dev/null
+++ b/tests/ui/async-await/futures-api.rs
@@ -0,0 +1,61 @@
+// run-pass
+
+// aux-build:arc_wake.rs
+
+extern crate arc_wake;
+
+use std::future::Future;
+use std::pin::Pin;
+use std::sync::{
+    Arc,
+    atomic::{self, AtomicUsize},
+};
+use std::task::{
+    Context, Poll,
+};
+use arc_wake::ArcWake;
+
+struct Counter {
+    wakes: AtomicUsize,
+}
+
+impl ArcWake for Counter {
+    fn wake(self: Arc<Self>) {
+        Self::wake_by_ref(&self)
+    }
+    fn wake_by_ref(arc_self: &Arc<Self>) {
+        arc_self.wakes.fetch_add(1, atomic::Ordering::SeqCst);
+    }
+}
+
+struct MyFuture;
+
+impl Future for MyFuture {
+    type Output = ();
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        // Wake twice
+        let waker = cx.waker();
+        waker.wake_by_ref();
+        waker.wake_by_ref();
+        Poll::Ready(())
+    }
+}
+
+fn test_waker() {
+    let counter = Arc::new(Counter {
+        wakes: AtomicUsize::new(0),
+    });
+    let waker = ArcWake::into_waker(counter.clone());
+    assert_eq!(2, Arc::strong_count(&counter));
+    {
+        let mut context = Context::from_waker(&waker);
+        assert_eq!(Poll::Ready(()), Pin::new(&mut MyFuture).poll(&mut context));
+        assert_eq!(2, counter.wakes.load(atomic::Ordering::SeqCst));
+    }
+    drop(waker);
+    assert_eq!(1, Arc::strong_count(&counter));
+}
+
+fn main() {
+    test_waker();
+}