1 files changed, 178 insertions, 0 deletions
diff --git a/third_party/rust/tokio/tests/sync_mutex.rs b/third_party/rust/tokio/tests/sync_mutex.rs
new file mode 100644
index 0000000000..51dbe03dc7
--- /dev/null
+++ b/third_party/rust/tokio/tests/sync_mutex.rs
@@ -0,0 +1,178 @@
+#![warn(rust_2018_idioms)]
+#![cfg(feature = "sync")]
+
+#[cfg(target_arch = "wasm32")]
+use wasm_bindgen_test::wasm_bindgen_test as test;
+#[cfg(target_arch = "wasm32")]
+use wasm_bindgen_test::wasm_bindgen_test as maybe_tokio_test;
+
+#[cfg(not(target_arch = "wasm32"))]
+use tokio::test as maybe_tokio_test;
+
+use tokio::sync::Mutex;
+use tokio_test::task::spawn;
+use tokio_test::{assert_pending, assert_ready};
+
+use std::sync::Arc;
+
+#[test]
+fn straight_execution() {
+    let l = Mutex::new(100);
+
+    {
+        let mut t = spawn(l.lock());
+        let mut g = assert_ready!(t.poll());
+        assert_eq!(&*g, &100);
+        *g = 99;
+    }
+    {
+        let mut t = spawn(l.lock());
+        let mut g = assert_ready!(t.poll());
+        assert_eq!(&*g, &99);
+        *g = 98;
+    }
+    {
+        let mut t = spawn(l.lock());
+        let g = assert_ready!(t.poll());
+        assert_eq!(&*g, &98);
+    }
+}
+
+#[test]
+fn readiness() {
+    let l1 = Arc::new(Mutex::new(100));
+    let l2 = Arc::clone(&l1);
+    let mut t1 = spawn(l1.lock());
+    let mut t2 = spawn(l2.lock());
+
+    let g = assert_ready!(t1.poll());
+
+    // We can't now acquire the lease since it's already held in g
+    assert_pending!(t2.poll());
+
+    // But once g unlocks, we can acquire it
+    drop(g);
+    assert!(t2.is_woken());
+    assert_ready!(t2.poll());
+}
+
+/*
+#[test]
+#[ignore]
+fn lock() {
+    let mut lock = Mutex::new(false);
+
+    let mut lock2 = lock.clone();
+    std::thread::spawn(move || {
+        let l = lock2.lock();
+        pin_mut!(l);
+
+        let mut task = MockTask::new();
+        let mut g = assert_ready!(task.poll(&mut l));
+        std::thread::sleep(std::time::Duration::from_millis(500));
+        *g = true;
+        drop(g);
+    });
+
+    std::thread::sleep(std::time::Duration::from_millis(50));
+    let mut task = MockTask::new();
+    let l = lock.lock();
+    pin_mut!(l);
+
+    assert_pending!(task.poll(&mut l));
+
+    std::thread::sleep(std::time::Duration::from_millis(500));
+    assert!(task.is_woken());
+    let result = assert_ready!(task.poll(&mut l));
+    assert!(*result);
+}
+*/
+
+/// Ensure a mutex is unlocked if a future holding the lock
+/// is aborted prematurely.
+#[tokio::test]
+#[cfg(feature = "full")]
+async fn aborted_future_1() {
+    use std::time::Duration;
+    use tokio::time::{interval, timeout};
+
+    let m1: Arc<Mutex<usize>> = Arc::new(Mutex::new(0));
+    {
+        let m2 = m1.clone();
+        // Try to lock mutex in a future that is aborted prematurely
+        timeout(Duration::from_millis(1u64), async move {
+            let iv = interval(Duration::from_millis(1000));
+            tokio::pin!(iv);
+            m2.lock().await;
+            iv.as_mut().tick().await;
+            iv.as_mut().tick().await;
+        })
+        .await
+        .unwrap_err();
+    }
+    // This should succeed as there is no lock left for the mutex.
+    timeout(Duration::from_millis(1u64), async move {
+        m1.lock().await;
+    })
+    .await
+    .expect("Mutex is locked");
+}
+
+/// This test is similar to `aborted_future_1` but this time the
+/// aborted future is waiting for the lock.
+#[tokio::test]
+#[cfg(feature = "full")]
+async fn aborted_future_2() {
+    use std::time::Duration;
+    use tokio::time::timeout;
+
+    let m1: Arc<Mutex<usize>> = Arc::new(Mutex::new(0));
+    {
+        // Lock mutex
+        let _lock = m1.lock().await;
+        {
+            let m2 = m1.clone();
+            // Try to lock mutex in a future that is aborted prematurely
+            timeout(Duration::from_millis(1u64), async move {
+                m2.lock().await;
+            })
+            .await
+            .unwrap_err();
+        }
+    }
+    // This should succeed as there is no lock left for the mutex.
+    timeout(Duration::from_millis(1u64), async move {
+        m1.lock().await;
+    })
+    .await
+    .expect("Mutex is locked");
+}
+
+#[test]
+fn try_lock() {
+    let m: Mutex<usize> = Mutex::new(0);
+    {
+        let g1 = m.try_lock();
+        assert!(g1.is_ok());
+        let g2 = m.try_lock();
+        assert!(!g2.is_ok());
+    }
+    let g3 = m.try_lock();
+    assert!(g3.is_ok());
+}
+
+#[maybe_tokio_test]
+async fn debug_format() {
+    let s = "debug";
+    let m = Mutex::new(s.to_string());
+    assert_eq!(format!("{:?}", s), format!("{:?}", m.lock().await));
+}
+
+#[maybe_tokio_test]
+async fn mutex_debug() {
+    let s = "data";
+    let m = Mutex::new(s.to_string());
+    assert_eq!(format!("{:?}", m), r#"Mutex { data: "data" }"#);
+    let _guard = m.lock().await;
+    assert_eq!(format!("{:?}", m), r#"Mutex { data: <locked> }"#)
+}