68 lines
1.8 KiB
Rust
68 lines
1.8 KiB
Rust
use futures::channel::mpsc;
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use futures::executor::{block_on, ThreadPool};
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use futures::future::{ready, FutureExt};
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use futures::lock::Mutex;
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use futures::stream::StreamExt;
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use futures::task::{Context, SpawnExt};
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use futures_test::future::FutureTestExt;
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use futures_test::task::{new_count_waker, panic_context};
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use std::sync::Arc;
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#[test]
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fn mutex_acquire_uncontested() {
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let mutex = Mutex::new(());
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for _ in 0..10 {
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assert!(mutex.lock().poll_unpin(&mut panic_context()).is_ready());
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}
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}
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#[test]
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fn mutex_wakes_waiters() {
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let mutex = Mutex::new(());
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let (waker, counter) = new_count_waker();
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let lock = mutex.lock().poll_unpin(&mut panic_context());
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assert!(lock.is_ready());
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let mut cx = Context::from_waker(&waker);
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let mut waiter = mutex.lock();
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assert!(waiter.poll_unpin(&mut cx).is_pending());
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assert_eq!(counter, 0);
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drop(lock);
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assert_eq!(counter, 1);
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assert!(waiter.poll_unpin(&mut panic_context()).is_ready());
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}
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#[cfg_attr(miri, ignore)] // https://github.com/rust-lang/miri/issues/1038
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#[test]
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fn mutex_contested() {
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let (tx, mut rx) = mpsc::unbounded();
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let pool = ThreadPool::builder().pool_size(16).create().unwrap();
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let tx = Arc::new(tx);
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let mutex = Arc::new(Mutex::new(0));
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let num_tasks = 1000;
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for _ in 0..num_tasks {
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let tx = tx.clone();
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let mutex = mutex.clone();
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pool.spawn(async move {
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let mut lock = mutex.lock().await;
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ready(()).pending_once().await;
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*lock += 1;
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tx.unbounded_send(()).unwrap();
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drop(lock);
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})
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.unwrap();
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}
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block_on(async {
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for _ in 0..num_tasks {
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rx.next().await.unwrap();
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}
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let lock = mutex.lock().await;
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assert_eq!(num_tasks, *lock);
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})
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}
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