1 files changed, 442 insertions, 0 deletions
diff --git a/library/std/src/sync/poison/mutex/tests.rs b/library/std/src/sync/poison/mutex/tests.rs
new file mode 100644
index 00000000000..395c8aada08
--- /dev/null
+++ b/library/std/src/sync/poison/mutex/tests.rs
@@ -0,0 +1,442 @@
+use crate::fmt::Debug;
+use crate::ops::FnMut;
+use crate::panic::{self, AssertUnwindSafe};
+use crate::sync::atomic::{AtomicUsize, Ordering};
+use crate::sync::mpsc::channel;
+use crate::sync::{Arc, Condvar, MappedMutexGuard, Mutex, MutexGuard, TryLockError};
+use crate::{hint, mem, thread};
+
+struct Packet<T>(Arc<(Mutex<T>, Condvar)>);
+
+#[derive(Eq, PartialEq, Debug)]
+struct NonCopy(i32);
+
+#[derive(Eq, PartialEq, Debug)]
+struct NonCopyNeedsDrop(i32);
+
+impl Drop for NonCopyNeedsDrop {
+    fn drop(&mut self) {
+        hint::black_box(());
+    }
+}
+
+#[test]
+fn test_needs_drop() {
+    assert!(!mem::needs_drop::<NonCopy>());
+    assert!(mem::needs_drop::<NonCopyNeedsDrop>());
+}
+
+#[derive(Clone, Eq, PartialEq, Debug)]
+struct Cloneable(i32);
+
+#[test]
+fn smoke() {
+    let m = Mutex::new(());
+    drop(m.lock().unwrap());
+    drop(m.lock().unwrap());
+}
+
+#[test]
+fn lots_and_lots() {
+    const J: u32 = 1000;
+    const K: u32 = 3;
+
+    let m = Arc::new(Mutex::new(0));
+
+    fn inc(m: &Mutex<u32>) {
+        for _ in 0..J {
+            *m.lock().unwrap() += 1;
+        }
+    }
+
+    let (tx, rx) = channel();
+    for _ in 0..K {
+        let tx2 = tx.clone();
+        let m2 = m.clone();
+        thread::spawn(move || {
+            inc(&m2);
+            tx2.send(()).unwrap();
+        });
+        let tx2 = tx.clone();
+        let m2 = m.clone();
+        thread::spawn(move || {
+            inc(&m2);
+            tx2.send(()).unwrap();
+        });
+    }
+
+    drop(tx);
+    for _ in 0..2 * K {
+        rx.recv().unwrap();
+    }
+    assert_eq!(*m.lock().unwrap(), J * K * 2);
+}
+
+#[test]
+fn try_lock() {
+    let m = Mutex::new(());
+    *m.try_lock().unwrap() = ();
+}
+
+fn new_poisoned_mutex<T>(value: T) -> Mutex<T> {
+    let mutex = Mutex::new(value);
+
+    let catch_unwind_result = panic::catch_unwind(AssertUnwindSafe(|| {
+        let _guard = mutex.lock().unwrap();
+
+        panic!("test panic to poison mutex");
+    }));
+
+    assert!(catch_unwind_result.is_err());
+    assert!(mutex.is_poisoned());
+
+    mutex
+}
+
+#[test]
+fn test_into_inner() {
+    let m = Mutex::new(NonCopy(10));
+    assert_eq!(m.into_inner().unwrap(), NonCopy(10));
+}
+
+#[test]
+fn test_into_inner_drop() {
+    struct Foo(Arc<AtomicUsize>);
+    impl Drop for Foo {
+        fn drop(&mut self) {
+            self.0.fetch_add(1, Ordering::SeqCst);
+        }
+    }
+    let num_drops = Arc::new(AtomicUsize::new(0));
+    let m = Mutex::new(Foo(num_drops.clone()));
+    assert_eq!(num_drops.load(Ordering::SeqCst), 0);
+    {
+        let _inner = m.into_inner().unwrap();
+        assert_eq!(num_drops.load(Ordering::SeqCst), 0);
+    }
+    assert_eq!(num_drops.load(Ordering::SeqCst), 1);
+}
+
+#[test]
+fn test_into_inner_poison() {
+    let m = new_poisoned_mutex(NonCopy(10));
+
+    match m.into_inner() {
+        Err(e) => assert_eq!(e.into_inner(), NonCopy(10)),
+        Ok(x) => panic!("into_inner of poisoned Mutex is Ok: {x:?}"),
+    }
+}
+
+#[test]
+fn test_get_cloned() {
+    let m = Mutex::new(Cloneable(10));
+
+    assert_eq!(m.get_cloned().unwrap(), Cloneable(10));
+}
+
+#[test]
+fn test_get_cloned_poison() {
+    let m = new_poisoned_mutex(Cloneable(10));
+
+    match m.get_cloned() {
+        Err(e) => assert_eq!(e.into_inner(), ()),
+        Ok(x) => panic!("get of poisoned Mutex is Ok: {x:?}"),
+    }
+}
+
+#[test]
+fn test_get_mut() {
+    let mut m = Mutex::new(NonCopy(10));
+    *m.get_mut().unwrap() = NonCopy(20);
+    assert_eq!(m.into_inner().unwrap(), NonCopy(20));
+}
+
+#[test]
+fn test_get_mut_poison() {
+    let mut m = new_poisoned_mutex(NonCopy(10));
+
+    match m.get_mut() {
+        Err(e) => assert_eq!(*e.into_inner(), NonCopy(10)),
+        Ok(x) => panic!("get_mut of poisoned Mutex is Ok: {x:?}"),
+    }
+}
+
+#[test]
+fn test_set() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = Mutex::new(init());
+
+        assert_eq!(*m.lock().unwrap(), init());
+        m.set(value()).unwrap();
+        assert_eq!(*m.lock().unwrap(), value());
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_set_poison() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = new_poisoned_mutex(init());
+
+        match m.set(value()) {
+            Err(e) => {
+                assert_eq!(e.into_inner(), value());
+                assert_eq!(m.into_inner().unwrap_err().into_inner(), init());
+            }
+            Ok(x) => panic!("set of poisoned Mutex is Ok: {x:?}"),
+        }
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_replace() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = Mutex::new(init());
+
+        assert_eq!(*m.lock().unwrap(), init());
+        assert_eq!(m.replace(value()).unwrap(), init());
+        assert_eq!(*m.lock().unwrap(), value());
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_replace_poison() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = new_poisoned_mutex(init());
+
+        match m.replace(value()) {
+            Err(e) => {
+                assert_eq!(e.into_inner(), value());
+                assert_eq!(m.into_inner().unwrap_err().into_inner(), init());
+            }
+            Ok(x) => panic!("replace of poisoned Mutex is Ok: {x:?}"),
+        }
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_mutex_arc_condvar() {
+    let packet = Packet(Arc::new((Mutex::new(false), Condvar::new())));
+    let packet2 = Packet(packet.0.clone());
+    let (tx, rx) = channel();
+    let _t = thread::spawn(move || {
+        // wait until parent gets in
+        rx.recv().unwrap();
+        let &(ref lock, ref cvar) = &*packet2.0;
+        let mut lock = lock.lock().unwrap();
+        *lock = true;
+        cvar.notify_one();
+    });
+
+    let &(ref lock, ref cvar) = &*packet.0;
+    let mut lock = lock.lock().unwrap();
+    tx.send(()).unwrap();
+    assert!(!*lock);
+    while !*lock {
+        lock = cvar.wait(lock).unwrap();
+    }
+}
+
+#[test]
+fn test_arc_condvar_poison() {
+    let packet = Packet(Arc::new((Mutex::new(1), Condvar::new())));
+    let packet2 = Packet(packet.0.clone());
+    let (tx, rx) = channel();
+
+    let _t = thread::spawn(move || -> () {
+        rx.recv().unwrap();
+        let &(ref lock, ref cvar) = &*packet2.0;
+        let _g = lock.lock().unwrap();
+        cvar.notify_one();
+        // Parent should fail when it wakes up.
+        panic!();
+    });
+
+    let &(ref lock, ref cvar) = &*packet.0;
+    let mut lock = lock.lock().unwrap();
+    tx.send(()).unwrap();
+    while *lock == 1 {
+        match cvar.wait(lock) {
+            Ok(l) => {
+                lock = l;
+                assert_eq!(*lock, 1);
+            }
+            Err(..) => break,
+        }
+    }
+}
+
+#[test]
+fn test_mutex_arc_poison() {
+    let arc = Arc::new(Mutex::new(1));
+    assert!(!arc.is_poisoned());
+    let arc2 = arc.clone();
+    let _ = thread::spawn(move || {
+        let lock = arc2.lock().unwrap();
+        assert_eq!(*lock, 2); // deliberate assertion failure to poison the mutex
+    })
+    .join();
+    assert!(arc.lock().is_err());
+    assert!(arc.is_poisoned());
+}
+
+#[test]
+fn test_mutex_arc_poison_mapped() {
+    let arc = Arc::new(Mutex::new(1));
+    assert!(!arc.is_poisoned());
+    let arc2 = arc.clone();
+    let _ = thread::spawn(move || {
+        let lock = arc2.lock().unwrap();
+        let lock = MutexGuard::map(lock, |val| val);
+        assert_eq!(*lock, 2); // deliberate assertion failure to poison the mutex
+    })
+    .join();
+    assert!(arc.lock().is_err());
+    assert!(arc.is_poisoned());
+}
+
+#[test]
+fn test_mutex_arc_nested() {
+    // Tests nested mutexes and access
+    // to underlying data.
+    let arc = Arc::new(Mutex::new(1));
+    let arc2 = Arc::new(Mutex::new(arc));
+    let (tx, rx) = channel();
+    let _t = thread::spawn(move || {
+        let lock = arc2.lock().unwrap();
+        let lock2 = lock.lock().unwrap();
+        assert_eq!(*lock2, 1);
+        tx.send(()).unwrap();
+    });
+    rx.recv().unwrap();
+}
+
+#[test]
+fn test_mutex_arc_access_in_unwind() {
+    let arc = Arc::new(Mutex::new(1));
+    let arc2 = arc.clone();
+    let _ = thread::spawn(move || -> () {
+        struct Unwinder {
+            i: Arc<Mutex<i32>>,
+        }
+        impl Drop for Unwinder {
+            fn drop(&mut self) {
+                *self.i.lock().unwrap() += 1;
+            }
+        }
+        let _u = Unwinder { i: arc2 };
+        panic!();
+    })
+    .join();
+    let lock = arc.lock().unwrap();
+    assert_eq!(*lock, 2);
+}
+
+#[test]
+fn test_mutex_unsized() {
+    let mutex: &Mutex<[i32]> = &Mutex::new([1, 2, 3]);
+    {
+        let b = &mut *mutex.lock().unwrap();
+        b[0] = 4;
+        b[2] = 5;
+    }
+    let comp: &[i32] = &[4, 2, 5];
+    assert_eq!(&*mutex.lock().unwrap(), comp);
+}
+
+#[test]
+fn test_mapping_mapped_guard() {
+    let arr = [0; 4];
+    let mut lock = Mutex::new(arr);
+    let guard = lock.lock().unwrap();
+    let guard = MutexGuard::map(guard, |arr| &mut arr[..2]);
+    let mut guard = MappedMutexGuard::map(guard, |slice| &mut slice[1..]);
+    assert_eq!(guard.len(), 1);
+    guard[0] = 42;
+    drop(guard);
+    assert_eq!(*lock.get_mut().unwrap(), [0, 42, 0, 0]);
+}
+
+#[test]
+fn panic_while_mapping_unlocked_poison() {
+    let lock = Mutex::new(());
+
+    let _ = panic::catch_unwind(|| {
+        let guard = lock.lock().unwrap();
+        let _guard = MutexGuard::map::<(), _>(guard, |_| panic!());
+    });
+
+    match lock.try_lock() {
+        Ok(_) => panic!("panicking in a MutexGuard::map closure should poison the Mutex"),
+        Err(TryLockError::WouldBlock) => {
+            panic!("panicking in a MutexGuard::map closure should unlock the mutex")
+        }
+        Err(TryLockError::Poisoned(_)) => {}
+    }
+
+    let _ = panic::catch_unwind(|| {
+        let guard = lock.lock().unwrap();
+        let _guard = MutexGuard::try_map::<(), _>(guard, |_| panic!());
+    });
+
+    match lock.try_lock() {
+        Ok(_) => panic!("panicking in a MutexGuard::try_map closure should poison the Mutex"),
+        Err(TryLockError::WouldBlock) => {
+            panic!("panicking in a MutexGuard::try_map closure should unlock the mutex")
+        }
+        Err(TryLockError::Poisoned(_)) => {}
+    }
+
+    let _ = panic::catch_unwind(|| {
+        let guard = lock.lock().unwrap();
+        let guard = MutexGuard::map::<(), _>(guard, |val| val);
+        let _guard = MappedMutexGuard::map::<(), _>(guard, |_| panic!());
+    });
+
+    match lock.try_lock() {
+        Ok(_) => panic!("panicking in a MappedMutexGuard::map closure should poison the Mutex"),
+        Err(TryLockError::WouldBlock) => {
+            panic!("panicking in a MappedMutexGuard::map closure should unlock the mutex")
+        }
+        Err(TryLockError::Poisoned(_)) => {}
+    }
+
+    let _ = panic::catch_unwind(|| {
+        let guard = lock.lock().unwrap();
+        let guard = MutexGuard::map::<(), _>(guard, |val| val);
+        let _guard = MappedMutexGuard::try_map::<(), _>(guard, |_| panic!());
+    });
+
+    match lock.try_lock() {
+        Ok(_) => panic!("panicking in a MappedMutexGuard::try_map closure should poison the Mutex"),
+        Err(TryLockError::WouldBlock) => {
+            panic!("panicking in a MappedMutexGuard::try_map closure should unlock the mutex")
+        }
+        Err(TryLockError::Poisoned(_)) => {}
+    }
+
+    drop(lock);
+}