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|
mod common;
use std::future::Future;
use std::mem::forget;
use std::pin::Pin;
use std::sync::{
atomic::{AtomicUsize, Ordering},
mpsc, Arc,
};
use std::task::Context;
use std::task::Poll;
use std::thread;
use common::check_yields_when_contended;
use async_lock::Semaphore;
use futures_lite::{future, pin};
#[test]
fn try_acquire() {
let s = Semaphore::new(2);
let g1 = s.try_acquire().unwrap();
let _g2 = s.try_acquire().unwrap();
assert!(s.try_acquire().is_none());
drop(g1);
assert!(s.try_acquire().is_some());
}
#[test]
fn stress() {
const COUNT: usize = if cfg!(miri) { 500 } else { 10_000 };
let s = Arc::new(Semaphore::new(5));
let (tx, rx) = mpsc::channel::<()>();
for _ in 0..50 {
let s = s.clone();
let tx = tx.clone();
thread::spawn(move || {
future::block_on(async {
for _ in 0..COUNT {
s.acquire().await;
}
drop(tx);
})
});
}
drop(tx);
let _ = rx.recv();
let _g1 = s.try_acquire().unwrap();
let g2 = s.try_acquire().unwrap();
let _g3 = s.try_acquire().unwrap();
let _g4 = s.try_acquire().unwrap();
let _g5 = s.try_acquire().unwrap();
assert!(s.try_acquire().is_none());
drop(g2);
assert!(s.try_acquire().is_some());
}
#[test]
fn as_mutex() {
let s = Arc::new(Semaphore::new(1));
let s2 = s.clone();
let _t = thread::spawn(move || {
future::block_on(async {
let _g = s2.acquire().await;
});
});
future::block_on(async {
let _g = s.acquire().await;
});
}
#[test]
fn multi_resource() {
let s = Arc::new(Semaphore::new(2));
let s2 = s.clone();
let (tx1, rx1) = mpsc::channel();
let (tx2, rx2) = mpsc::channel();
let _t = thread::spawn(move || {
future::block_on(async {
let _g = s2.acquire().await;
let _ = rx2.recv();
tx1.send(()).unwrap();
});
});
future::block_on(async {
let _g = s.acquire().await;
tx2.send(()).unwrap();
rx1.recv().unwrap();
});
}
#[test]
fn lifetime() {
// Show that the future keeps the semaphore alive.
let _fut = {
let mutex = Arc::new(Semaphore::new(2));
mutex.acquire_arc()
};
}
#[test]
fn yields_when_contended() {
let s = Semaphore::new(1);
check_yields_when_contended(s.try_acquire().unwrap(), s.acquire());
let s = Arc::new(s);
check_yields_when_contended(s.try_acquire_arc().unwrap(), s.acquire_arc());
}
#[cfg(all(feature = "std", not(target_family = "wasm")))]
#[test]
fn smoke_blocking() {
let s = Semaphore::new(2);
let g1 = s.acquire_blocking();
let _g2 = s.acquire_blocking();
assert!(s.try_acquire().is_none());
drop(g1);
assert!(s.try_acquire().is_some());
}
#[cfg(all(feature = "std", not(target_family = "wasm")))]
#[test]
fn smoke_arc_blocking() {
let s = Arc::new(Semaphore::new(2));
let g1 = s.acquire_arc_blocking();
let _g2 = s.acquire_arc_blocking();
assert!(s.try_acquire().is_none());
drop(g1);
assert!(s.try_acquire().is_some());
}
#[test]
fn add_permits() {
static COUNTER: AtomicUsize = AtomicUsize::new(0);
let s = Arc::new(Semaphore::new(0));
let (tx, rx) = mpsc::channel::<()>();
for _ in 0..50 {
let s = s.clone();
let tx = tx.clone();
thread::spawn(move || {
future::block_on(async {
let perm = s.acquire().await;
forget(perm);
COUNTER.fetch_add(1, Ordering::Relaxed);
drop(tx);
})
});
}
assert_eq!(COUNTER.load(Ordering::Relaxed), 0);
s.add_permits(50);
drop(tx);
let _ = rx.recv();
assert_eq!(COUNTER.load(Ordering::Relaxed), 50);
}
#[test]
fn add_permits_2() {
future::block_on(AddPermitsTest);
}
struct AddPermitsTest;
impl Future for AddPermitsTest {
type Output = ();
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<()> {
let s = Semaphore::new(0);
let acq = s.acquire();
pin!(acq);
let acq_2 = s.acquire();
pin!(acq_2);
assert!(acq.as_mut().poll(cx).is_pending());
assert!(acq_2.as_mut().poll(cx).is_pending());
s.add_permits(1);
let g = acq.poll(cx);
assert!(g.is_ready());
assert!(acq_2.poll(cx).is_pending());
Poll::Ready(())
}
}
|
