1 files changed, 462 insertions, 0 deletions
diff --git a/third_party/rust/tokio/tests/sync_broadcast.rs b/third_party/rust/tokio/tests/sync_broadcast.rs
new file mode 100644
index 0000000000..1b68eb7edb
--- /dev/null
+++ b/third_party/rust/tokio/tests/sync_broadcast.rs
@@ -0,0 +1,462 @@
+#![allow(clippy::cognitive_complexity)]
+#![warn(rust_2018_idioms)]
+#![cfg(feature = "sync")]
+
+#[cfg(target_arch = "wasm32")]
+use wasm_bindgen_test::wasm_bindgen_test as test;
+
+use tokio::sync::broadcast;
+use tokio_test::task;
+use tokio_test::{
+    assert_err, assert_ok, assert_pending, assert_ready, assert_ready_err, assert_ready_ok,
+};
+
+use std::sync::Arc;
+
+macro_rules! assert_recv {
+    ($e:expr) => {
+        match $e.try_recv() {
+            Ok(value) => value,
+            Err(e) => panic!("expected recv; got = {:?}", e),
+        }
+    };
+}
+
+macro_rules! assert_empty {
+    ($e:expr) => {
+        match $e.try_recv() {
+            Ok(value) => panic!("expected empty; got = {:?}", value),
+            Err(broadcast::error::TryRecvError::Empty) => {}
+            Err(e) => panic!("expected empty; got = {:?}", e),
+        }
+    };
+}
+
+macro_rules! assert_lagged {
+    ($e:expr, $n:expr) => {
+        match assert_err!($e) {
+            broadcast::error::TryRecvError::Lagged(n) => {
+                assert_eq!(n, $n);
+            }
+            _ => panic!("did not lag"),
+        }
+    };
+}
+
+macro_rules! assert_closed {
+    ($e:expr) => {
+        match assert_err!($e) {
+            broadcast::error::TryRecvError::Closed => {}
+            _ => panic!("did not lag"),
+        }
+    };
+}
+
+trait AssertSend: Send + Sync {}
+impl AssertSend for broadcast::Sender<i32> {}
+impl AssertSend for broadcast::Receiver<i32> {}
+
+#[test]
+fn send_try_recv_bounded() {
+    let (tx, mut rx) = broadcast::channel(16);
+
+    assert_empty!(rx);
+
+    let n = assert_ok!(tx.send("hello"));
+    assert_eq!(n, 1);
+
+    let val = assert_recv!(rx);
+    assert_eq!(val, "hello");
+
+    assert_empty!(rx);
+}
+
+#[test]
+fn send_two_recv() {
+    let (tx, mut rx1) = broadcast::channel(16);
+    let mut rx2 = tx.subscribe();
+
+    assert_empty!(rx1);
+    assert_empty!(rx2);
+
+    let n = assert_ok!(tx.send("hello"));
+    assert_eq!(n, 2);
+
+    let val = assert_recv!(rx1);
+    assert_eq!(val, "hello");
+
+    let val = assert_recv!(rx2);
+    assert_eq!(val, "hello");
+
+    assert_empty!(rx1);
+    assert_empty!(rx2);
+}
+
+#[test]
+fn send_recv_bounded() {
+    let (tx, mut rx) = broadcast::channel(16);
+
+    let mut recv = task::spawn(rx.recv());
+
+    assert_pending!(recv.poll());
+
+    assert_ok!(tx.send("hello"));
+
+    assert!(recv.is_woken());
+    let val = assert_ready_ok!(recv.poll());
+    assert_eq!(val, "hello");
+}
+
+#[test]
+fn send_two_recv_bounded() {
+    let (tx, mut rx1) = broadcast::channel(16);
+    let mut rx2 = tx.subscribe();
+
+    let mut recv1 = task::spawn(rx1.recv());
+    let mut recv2 = task::spawn(rx2.recv());
+
+    assert_pending!(recv1.poll());
+    assert_pending!(recv2.poll());
+
+    assert_ok!(tx.send("hello"));
+
+    assert!(recv1.is_woken());
+    assert!(recv2.is_woken());
+
+    let val1 = assert_ready_ok!(recv1.poll());
+    let val2 = assert_ready_ok!(recv2.poll());
+    assert_eq!(val1, "hello");
+    assert_eq!(val2, "hello");
+
+    drop((recv1, recv2));
+
+    let mut recv1 = task::spawn(rx1.recv());
+    let mut recv2 = task::spawn(rx2.recv());
+
+    assert_pending!(recv1.poll());
+
+    assert_ok!(tx.send("world"));
+
+    assert!(recv1.is_woken());
+    assert!(!recv2.is_woken());
+
+    let val1 = assert_ready_ok!(recv1.poll());
+    let val2 = assert_ready_ok!(recv2.poll());
+    assert_eq!(val1, "world");
+    assert_eq!(val2, "world");
+}
+
+#[test]
+fn change_tasks() {
+    let (tx, mut rx) = broadcast::channel(1);
+
+    let mut recv = Box::pin(rx.recv());
+
+    let mut task1 = task::spawn(&mut recv);
+    assert_pending!(task1.poll());
+
+    let mut task2 = task::spawn(&mut recv);
+    assert_pending!(task2.poll());
+
+    tx.send("hello").unwrap();
+
+    assert!(task2.is_woken());
+}
+
+#[test]
+fn send_slow_rx() {
+    let (tx, mut rx1) = broadcast::channel(16);
+    let mut rx2 = tx.subscribe();
+
+    {
+        let mut recv2 = task::spawn(rx2.recv());
+
+        {
+            let mut recv1 = task::spawn(rx1.recv());
+
+            assert_pending!(recv1.poll());
+            assert_pending!(recv2.poll());
+
+            assert_ok!(tx.send("one"));
+
+            assert!(recv1.is_woken());
+            assert!(recv2.is_woken());
+
+            assert_ok!(tx.send("two"));
+
+            let val = assert_ready_ok!(recv1.poll());
+            assert_eq!(val, "one");
+        }
+
+        let val = assert_ready_ok!(task::spawn(rx1.recv()).poll());
+        assert_eq!(val, "two");
+
+        let mut recv1 = task::spawn(rx1.recv());
+
+        assert_pending!(recv1.poll());
+
+        assert_ok!(tx.send("three"));
+
+        assert!(recv1.is_woken());
+
+        let val = assert_ready_ok!(recv1.poll());
+        assert_eq!(val, "three");
+
+        let val = assert_ready_ok!(recv2.poll());
+        assert_eq!(val, "one");
+    }
+
+    let val = assert_recv!(rx2);
+    assert_eq!(val, "two");
+
+    let val = assert_recv!(rx2);
+    assert_eq!(val, "three");
+}
+
+#[test]
+fn drop_rx_while_values_remain() {
+    let (tx, mut rx1) = broadcast::channel(16);
+    let mut rx2 = tx.subscribe();
+
+    assert_ok!(tx.send("one"));
+    assert_ok!(tx.send("two"));
+
+    assert_recv!(rx1);
+    assert_recv!(rx2);
+
+    drop(rx2);
+    drop(rx1);
+}
+
+#[test]
+fn lagging_rx() {
+    let (tx, mut rx1) = broadcast::channel(2);
+    let mut rx2 = tx.subscribe();
+
+    assert_ok!(tx.send("one"));
+    assert_ok!(tx.send("two"));
+
+    assert_eq!("one", assert_recv!(rx1));
+
+    assert_ok!(tx.send("three"));
+
+    // Lagged too far
+    let x = dbg!(rx2.try_recv());
+    assert_lagged!(x, 1);
+
+    // Calling again gets the next value
+    assert_eq!("two", assert_recv!(rx2));
+
+    assert_eq!("two", assert_recv!(rx1));
+    assert_eq!("three", assert_recv!(rx1));
+
+    assert_ok!(tx.send("four"));
+    assert_ok!(tx.send("five"));
+
+    assert_lagged!(rx2.try_recv(), 1);
+
+    assert_ok!(tx.send("six"));
+
+    assert_lagged!(rx2.try_recv(), 1);
+}
+
+#[test]
+fn send_no_rx() {
+    let (tx, _) = broadcast::channel(16);
+
+    assert_err!(tx.send("hello"));
+
+    let mut rx = tx.subscribe();
+
+    assert_ok!(tx.send("world"));
+
+    let val = assert_recv!(rx);
+    assert_eq!("world", val);
+}
+
+#[test]
+#[should_panic]
+#[cfg(not(target_arch = "wasm32"))] // wasm currently doesn't support unwinding
+fn zero_capacity() {
+    broadcast::channel::<()>(0);
+}
+
+#[test]
+#[should_panic]
+#[cfg(not(target_arch = "wasm32"))] // wasm currently doesn't support unwinding
+fn capacity_too_big() {
+    use std::usize;
+
+    broadcast::channel::<()>(1 + (usize::MAX >> 1));
+}
+
+#[test]
+#[cfg(not(target_arch = "wasm32"))] // wasm currently doesn't support unwinding
+fn panic_in_clone() {
+    use std::panic::{self, AssertUnwindSafe};
+
+    #[derive(Eq, PartialEq, Debug)]
+    struct MyVal(usize);
+
+    impl Clone for MyVal {
+        fn clone(&self) -> MyVal {
+            assert_ne!(0, self.0);
+            MyVal(self.0)
+        }
+    }
+
+    let (tx, mut rx) = broadcast::channel(16);
+
+    assert_ok!(tx.send(MyVal(0)));
+    assert_ok!(tx.send(MyVal(1)));
+
+    let res = panic::catch_unwind(AssertUnwindSafe(|| {
+        let _ = rx.try_recv();
+    }));
+
+    assert_err!(res);
+
+    let val = assert_recv!(rx);
+    assert_eq!(val, MyVal(1));
+}
+
+#[test]
+fn dropping_tx_notifies_rx() {
+    let (tx, mut rx1) = broadcast::channel::<()>(16);
+    let mut rx2 = tx.subscribe();
+
+    let tx2 = tx.clone();
+
+    let mut recv1 = task::spawn(rx1.recv());
+    let mut recv2 = task::spawn(rx2.recv());
+
+    assert_pending!(recv1.poll());
+    assert_pending!(recv2.poll());
+
+    drop(tx);
+
+    assert_pending!(recv1.poll());
+    assert_pending!(recv2.poll());
+
+    drop(tx2);
+
+    assert!(recv1.is_woken());
+    assert!(recv2.is_woken());
+
+    let err = assert_ready_err!(recv1.poll());
+    assert!(is_closed(err));
+
+    let err = assert_ready_err!(recv2.poll());
+    assert!(is_closed(err));
+}
+
+#[test]
+fn unconsumed_messages_are_dropped() {
+    let (tx, rx) = broadcast::channel(16);
+
+    let msg = Arc::new(());
+
+    assert_ok!(tx.send(msg.clone()));
+
+    assert_eq!(2, Arc::strong_count(&msg));
+
+    drop(rx);
+
+    assert_eq!(1, Arc::strong_count(&msg));
+}
+
+#[test]
+fn single_capacity_recvs() {
+    let (tx, mut rx) = broadcast::channel(1);
+
+    assert_ok!(tx.send(1));
+
+    assert_eq!(assert_recv!(rx), 1);
+    assert_empty!(rx);
+}
+
+#[test]
+fn single_capacity_recvs_after_drop_1() {
+    let (tx, mut rx) = broadcast::channel(1);
+
+    assert_ok!(tx.send(1));
+    drop(tx);
+
+    assert_eq!(assert_recv!(rx), 1);
+    assert_closed!(rx.try_recv());
+}
+
+#[test]
+fn single_capacity_recvs_after_drop_2() {
+    let (tx, mut rx) = broadcast::channel(1);
+
+    assert_ok!(tx.send(1));
+    assert_ok!(tx.send(2));
+    drop(tx);
+
+    assert_lagged!(rx.try_recv(), 1);
+    assert_eq!(assert_recv!(rx), 2);
+    assert_closed!(rx.try_recv());
+}
+
+#[test]
+fn dropping_sender_does_not_overwrite() {
+    let (tx, mut rx) = broadcast::channel(2);
+
+    assert_ok!(tx.send(1));
+    assert_ok!(tx.send(2));
+    drop(tx);
+
+    assert_eq!(assert_recv!(rx), 1);
+    assert_eq!(assert_recv!(rx), 2);
+    assert_closed!(rx.try_recv());
+}
+
+#[test]
+fn lagging_receiver_recovers_after_wrap_closed_1() {
+    let (tx, mut rx) = broadcast::channel(2);
+
+    assert_ok!(tx.send(1));
+    assert_ok!(tx.send(2));
+    assert_ok!(tx.send(3));
+    drop(tx);
+
+    assert_lagged!(rx.try_recv(), 1);
+    assert_eq!(assert_recv!(rx), 2);
+    assert_eq!(assert_recv!(rx), 3);
+    assert_closed!(rx.try_recv());
+}
+
+#[test]
+fn lagging_receiver_recovers_after_wrap_closed_2() {
+    let (tx, mut rx) = broadcast::channel(2);
+
+    assert_ok!(tx.send(1));
+    assert_ok!(tx.send(2));
+    assert_ok!(tx.send(3));
+    assert_ok!(tx.send(4));
+    drop(tx);
+
+    assert_lagged!(rx.try_recv(), 2);
+    assert_eq!(assert_recv!(rx), 3);
+    assert_eq!(assert_recv!(rx), 4);
+    assert_closed!(rx.try_recv());
+}
+
+#[test]
+fn lagging_receiver_recovers_after_wrap_open() {
+    let (tx, mut rx) = broadcast::channel(2);
+
+    assert_ok!(tx.send(1));
+    assert_ok!(tx.send(2));
+    assert_ok!(tx.send(3));
+
+    assert_lagged!(rx.try_recv(), 1);
+    assert_eq!(assert_recv!(rx), 2);
+    assert_eq!(assert_recv!(rx), 3);
+    assert_empty!(rx);
+}
+
+fn is_closed(err: broadcast::error::RecvError) -> bool {
+    matches!(err, broadcast::error::RecvError::Closed)
+}