1 files changed, 299 insertions, 0 deletions
diff --git a/third_party/rust/async-task/tests/basic.rs b/third_party/rust/async-task/tests/basic.rs
new file mode 100644
index 0000000000..c2230434aa
--- /dev/null
+++ b/third_party/rust/async-task/tests/basic.rs
@@ -0,0 +1,299 @@
+use std::future::Future;
+use std::pin::Pin;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::task::{Context, Poll};
+
+use async_task::Runnable;
+use smol::future;
+
+// Creates a future with event counters.
+//
+// Usage: `future!(f, POLL, DROP)`
+//
+// The future `f` always returns `Poll::Ready`.
+// When it gets polled, `POLL` is incremented.
+// When it gets dropped, `DROP` is incremented.
+macro_rules! future {
+    ($name:pat, $poll:ident, $drop:ident) => {
+        static $poll: AtomicUsize = AtomicUsize::new(0);
+        static $drop: AtomicUsize = AtomicUsize::new(0);
+
+        let $name = {
+            struct Fut(Box<i32>);
+
+            impl Future for Fut {
+                type Output = Box<i32>;
+
+                fn poll(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Self::Output> {
+                    $poll.fetch_add(1, Ordering::SeqCst);
+                    Poll::Ready(Box::new(0))
+                }
+            }
+
+            impl Drop for Fut {
+                fn drop(&mut self) {
+                    $drop.fetch_add(1, Ordering::SeqCst);
+                }
+            }
+
+            Fut(Box::new(0))
+        };
+    };
+}
+
+// Creates a schedule function with event counters.
+//
+// Usage: `schedule!(s, SCHED, DROP)`
+//
+// The schedule function `s` does nothing.
+// When it gets invoked, `SCHED` is incremented.
+// When it gets dropped, `DROP` is incremented.
+macro_rules! schedule {
+    ($name:pat, $sched:ident, $drop:ident) => {
+        static $drop: AtomicUsize = AtomicUsize::new(0);
+        static $sched: AtomicUsize = AtomicUsize::new(0);
+
+        let $name = {
+            struct Guard(Box<i32>);
+
+            impl Drop for Guard {
+                fn drop(&mut self) {
+                    $drop.fetch_add(1, Ordering::SeqCst);
+                }
+            }
+
+            let guard = Guard(Box::new(0));
+            move |_runnable| {
+                let _ = &guard;
+                $sched.fetch_add(1, Ordering::SeqCst);
+            }
+        };
+    };
+}
+
+fn try_await<T>(f: impl Future<Output = T>) -> Option<T> {
+    future::block_on(future::poll_once(f))
+}
+
+#[test]
+fn drop_and_detach() {
+    future!(f, POLL, DROP_F);
+    schedule!(s, SCHEDULE, DROP_S);
+    let (runnable, task) = async_task::spawn(f, s);
+
+    assert_eq!(POLL.load(Ordering::SeqCst), 0);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    drop(runnable);
+    assert_eq!(POLL.load(Ordering::SeqCst), 0);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    task.detach();
+    assert_eq!(POLL.load(Ordering::SeqCst), 0);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 1);
+}
+
+#[test]
+fn detach_and_drop() {
+    future!(f, POLL, DROP_F);
+    schedule!(s, SCHEDULE, DROP_S);
+    let (runnable, task) = async_task::spawn(f, s);
+
+    task.detach();
+    assert_eq!(POLL.load(Ordering::SeqCst), 0);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    drop(runnable);
+    assert_eq!(POLL.load(Ordering::SeqCst), 0);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 1);
+}
+
+#[test]
+fn detach_and_run() {
+    future!(f, POLL, DROP_F);
+    schedule!(s, SCHEDULE, DROP_S);
+    let (runnable, task) = async_task::spawn(f, s);
+
+    task.detach();
+    assert_eq!(POLL.load(Ordering::SeqCst), 0);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    runnable.run();
+    assert_eq!(POLL.load(Ordering::SeqCst), 1);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 1);
+}
+
+#[test]
+fn run_and_detach() {
+    future!(f, POLL, DROP_F);
+    schedule!(s, SCHEDULE, DROP_S);
+    let (runnable, task) = async_task::spawn(f, s);
+
+    runnable.run();
+    assert_eq!(POLL.load(Ordering::SeqCst), 1);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    task.detach();
+    assert_eq!(POLL.load(Ordering::SeqCst), 1);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 1);
+}
+
+#[test]
+fn cancel_and_run() {
+    future!(f, POLL, DROP_F);
+    schedule!(s, SCHEDULE, DROP_S);
+    let (runnable, task) = async_task::spawn(f, s);
+
+    drop(task);
+    assert_eq!(POLL.load(Ordering::SeqCst), 0);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    runnable.run();
+    assert_eq!(POLL.load(Ordering::SeqCst), 0);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 1);
+}
+
+#[test]
+fn run_and_cancel() {
+    future!(f, POLL, DROP_F);
+    schedule!(s, SCHEDULE, DROP_S);
+    let (runnable, task) = async_task::spawn(f, s);
+
+    runnable.run();
+    assert_eq!(POLL.load(Ordering::SeqCst), 1);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    drop(task);
+    assert_eq!(POLL.load(Ordering::SeqCst), 1);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 1);
+}
+
+#[test]
+fn cancel_join() {
+    future!(f, POLL, DROP_F);
+    schedule!(s, SCHEDULE, DROP_S);
+    let (runnable, mut task) = async_task::spawn(f, s);
+
+    assert!(try_await(&mut task).is_none());
+    assert_eq!(POLL.load(Ordering::SeqCst), 0);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    runnable.run();
+    assert_eq!(POLL.load(Ordering::SeqCst), 1);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    assert!(try_await(&mut task).is_some());
+    assert_eq!(POLL.load(Ordering::SeqCst), 1);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 0);
+
+    drop(task);
+    assert_eq!(POLL.load(Ordering::SeqCst), 1);
+    assert_eq!(SCHEDULE.load(Ordering::SeqCst), 0);
+    assert_eq!(DROP_F.load(Ordering::SeqCst), 1);
+    assert_eq!(DROP_S.load(Ordering::SeqCst), 1);
+}
+
+#[test]
+fn schedule() {
+    let (s, r) = flume::unbounded();
+    let schedule = move |runnable| s.send(runnable).unwrap();
+    let (runnable, _task) = async_task::spawn(future::poll_fn(|_| Poll::<()>::Pending), schedule);
+
+    assert!(r.is_empty());
+    runnable.schedule();
+
+    let runnable = r.recv().unwrap();
+    assert!(r.is_empty());
+    runnable.schedule();
+
+    let runnable = r.recv().unwrap();
+    assert!(r.is_empty());
+    runnable.schedule();
+
+    r.recv().unwrap();
+}
+
+#[test]
+fn schedule_counter() {
+    static COUNT: AtomicUsize = AtomicUsize::new(0);
+
+    let (s, r) = flume::unbounded();
+    let schedule = move |runnable: Runnable| {
+        COUNT.fetch_add(1, Ordering::SeqCst);
+        s.send(runnable).unwrap();
+    };
+    let (runnable, _task) = async_task::spawn(future::poll_fn(|_| Poll::<()>::Pending), schedule);
+    runnable.schedule();
+
+    r.recv().unwrap().schedule();
+    r.recv().unwrap().schedule();
+    assert_eq!(COUNT.load(Ordering::SeqCst), 3);
+    r.recv().unwrap();
+}
+
+#[test]
+fn drop_inside_schedule() {
+    struct DropGuard(AtomicUsize);
+    impl Drop for DropGuard {
+        fn drop(&mut self) {
+            self.0.fetch_add(1, Ordering::SeqCst);
+        }
+    }
+    let guard = DropGuard(AtomicUsize::new(0));
+
+    let (runnable, _) = async_task::spawn(async {}, move |runnable| {
+        assert_eq!(guard.0.load(Ordering::SeqCst), 0);
+        drop(runnable);
+        assert_eq!(guard.0.load(Ordering::SeqCst), 0);
+    });
+    runnable.schedule();
+}
+
+#[test]
+fn waker() {
+    let (s, r) = flume::unbounded();
+    let schedule = move |runnable| s.send(runnable).unwrap();
+    let (runnable, _task) = async_task::spawn(future::poll_fn(|_| Poll::<()>::Pending), schedule);
+
+    assert!(r.is_empty());
+    let waker = runnable.waker();
+    runnable.run();
+    waker.wake_by_ref();
+
+    let runnable = r.recv().unwrap();
+    runnable.run();
+    waker.wake();
+    r.recv().unwrap();
+}