async-std/tests/condvar.rs

#![cfg(feature = "unstable")]
use std::sync::Arc;
use std::time::Duration;

use async_std::sync::{Condvar, Mutex};
use async_std::task::{self, JoinHandle};

#[test]
fn wait_timeout_with_lock() {
    task::block_on(async {
        let pair = Arc::new((Mutex::new(false), Condvar::new()));
        let pair2 = pair.clone();

        task::spawn(async move {
            let (m, c) = &*pair2;
            let _g = m.lock().await;
            task::sleep(Duration::from_millis(20)).await;
            c.notify_one();
        });

        let (m, c) = &*pair;
        let (_, wait_result) = c
            .wait_timeout(m.lock().await, Duration::from_millis(10))
            .await;
        assert!(wait_result.timed_out());
    })
}

#[test]
fn wait_timeout_without_lock() {
    task::block_on(async {
        let m = Mutex::new(false);
        let c = Condvar::new();

        let (_, wait_result) = c
            .wait_timeout(m.lock().await, Duration::from_millis(10))
            .await;
        assert!(wait_result.timed_out());
    })
}

#[test]
fn wait_timeout_until_timed_out() {
    task::block_on(async {
        let m = Mutex::new(false);
        let c = Condvar::new();

        let (_, wait_result) = c
            .wait_timeout_until(m.lock().await, Duration::from_millis(10), |&mut started| {
                started
            })
            .await;
        assert!(wait_result.timed_out());
    })
}

#[test]
fn notify_all() {
    task::block_on(async {
        let mut tasks: Vec<JoinHandle<()>> = Vec::new();
        let pair = Arc::new((Mutex::new(0u32), Condvar::new()));

        for _ in 0..10 {
            let pair = pair.clone();
            tasks.push(task::spawn(async move {
                let (m, c) = &*pair;
                let mut count = m.lock().await;
                while *count == 0 {
                    count = c.wait(count).await;
                }
                *count += 1;
            }));
        }

        // Give some time for tasks to start up
        task::sleep(Duration::from_millis(5)).await;

        let (m, c) = &*pair;
        {
            let mut count = m.lock().await;
            *count += 1;
            c.notify_all();
        }

        for t in tasks {
            t.await;
        }
        let count = m.lock().await;
        assert_eq!(11, *count);
    })
}