sync_mutex_owned.rs

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#![warn(rust_2018_idioms)]

#![cfg(feature = "sync")]

#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]

use wasm_bindgen_test::wasm_bindgen_test as test;

#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]

use wasm_bindgen_test::wasm_bindgen_test as maybe_tokio_test;

#[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]

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 = Arc::new(Mutex::new(100));

        let mut t = spawn(l.clone().lock_owned());

        let mut g = assert_ready!(t.poll());

        assert_eq!(&*g, &100);

        *g = 99;

        let mut t = spawn(l.clone().lock_owned());

        let mut g = assert_ready!(t.poll());

        assert_eq!(&*g, &99);

        *g = 98;

        let mut t = spawn(l.lock_owned());

        let g = assert_ready!(t.poll());

        assert_eq!(&*g, &98);

#[test]

fn readiness() {

    let l = Arc::new(Mutex::new(100));

    let mut t1 = spawn(l.clone().lock_owned());

    let mut t2 = spawn(l.lock_owned());

    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());

/// 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_owned().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_owned().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.clone().lock_owned().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_owned().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_owned().await;

})

    .await

    .expect("Mutex is locked");

#[test]

fn try_lock_owned() {

    let m: Arc<Mutex<usize>> = Arc::new(Mutex::new(0));

        let g1 = m.clone().try_lock_owned();

        assert!(g1.is_ok());

        let g2 = m.clone().try_lock_owned();

        assert!(g2.is_err());

    let g3 = m.try_lock_owned();

    assert!(g3.is_ok());

#[maybe_tokio_test]

async fn debug_format() {

    let s = "debug";

    let m = Arc::new(Mutex::new(s.to_string()));

    assert_eq!(format!("{:?}", s), format!("{:?}", m.lock_owned().await));