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#![cfg(feature = "sync")]
#[cfg(tokio_wasm_not_wasi)]
use wasm_bindgen_test::wasm_bindgen_test as test;
use std::sync::Arc;
use tokio::sync::Semaphore;
#[test]
fn no_permits() {
// this should not panic
Semaphore::new(0);
}
#[test]
fn try_acquire() {
let sem = Semaphore::new(1);
{
let p1 = sem.try_acquire();
assert!(p1.is_ok());
let p2 = sem.try_acquire();
assert!(p2.is_err());
}
let p3 = sem.try_acquire();
assert!(p3.is_ok());
}
#[tokio::test]
#[cfg(feature = "full")]
async fn acquire() {
let sem = Arc::new(Semaphore::new(1));
let p1 = sem.try_acquire().unwrap();
let sem_clone = sem.clone();
let j = tokio::spawn(async move {
let _p2 = sem_clone.acquire().await;
});
drop(p1);
j.await.unwrap();
}
#[tokio::test]
#[cfg(feature = "full")]
async fn add_permits() {
let sem = Arc::new(Semaphore::new(0));
let sem_clone = sem.clone();
let j = tokio::spawn(async move {
let _p2 = sem_clone.acquire().await;
});
sem.add_permits(1);
j.await.unwrap();
}
#[test]
fn forget() {
let sem = Arc::new(Semaphore::new(1));
{
let p = sem.try_acquire().unwrap();
assert_eq!(sem.available_permits(), 0);
p.forget();
assert_eq!(sem.available_permits(), 0);
}
assert_eq!(sem.available_permits(), 0);
assert!(sem.try_acquire().is_err());
}
#[test]
fn merge() {
let sem = Arc::new(Semaphore::new(3));
{
let mut p1 = sem.try_acquire().unwrap();
assert_eq!(sem.available_permits(), 2);
let p2 = sem.try_acquire_many(2).unwrap();
assert_eq!(sem.available_permits(), 0);
p1.merge(p2);
assert_eq!(sem.available_permits(), 0);
}
assert_eq!(sem.available_permits(), 3);
}
#[test]
#[cfg(not(tokio_wasm))] // No stack unwinding on wasm targets
#[should_panic]
fn merge_unrelated_permits() {
let sem1 = Arc::new(Semaphore::new(3));
let sem2 = Arc::new(Semaphore::new(3));
let mut p1 = sem1.try_acquire().unwrap();
let p2 = sem2.try_acquire().unwrap();
p1.merge(p2);
}
#[tokio::test]
#[cfg(feature = "full")]
async fn stress_test() {
let sem = Arc::new(Semaphore::new(5));
let mut join_handles = Vec::new();
for _ in 0..1000 {
let sem_clone = sem.clone();
join_handles.push(tokio::spawn(async move {
let _p = sem_clone.acquire().await;
}));
}
for j in join_handles {
j.await.unwrap();
}
// there should be exactly 5 semaphores available now
let _p1 = sem.try_acquire().unwrap();
let _p2 = sem.try_acquire().unwrap();
let _p3 = sem.try_acquire().unwrap();
let _p4 = sem.try_acquire().unwrap();
let _p5 = sem.try_acquire().unwrap();
assert!(sem.try_acquire().is_err());
}
#[test]
fn add_max_amount_permits() {
let s = tokio::sync::Semaphore::new(0);
s.add_permits(tokio::sync::Semaphore::MAX_PERMITS);
assert_eq!(s.available_permits(), tokio::sync::Semaphore::MAX_PERMITS);
}
#[cfg(not(tokio_wasm))] // wasm currently doesn't support unwinding
#[test]
#[should_panic]
fn add_more_than_max_amount_permits1() {
let s = tokio::sync::Semaphore::new(1);
s.add_permits(tokio::sync::Semaphore::MAX_PERMITS);
}
#[cfg(not(tokio_wasm))] // wasm currently doesn't support unwinding
#[test]
#[should_panic]
fn add_more_than_max_amount_permits2() {
let s = Semaphore::new(Semaphore::MAX_PERMITS - 1);
s.add_permits(1);
s.add_permits(1);
}
#[cfg(not(tokio_wasm))] // wasm currently doesn't support unwinding
#[test]
#[should_panic]
fn panic_when_exceeds_maxpermits() {
let _ = Semaphore::new(Semaphore::MAX_PERMITS + 1);
}
#[test]
fn no_panic_at_maxpermits() {
let _ = Semaphore::new(Semaphore::MAX_PERMITS);
let s = Semaphore::new(Semaphore::MAX_PERMITS - 1);
s.add_permits(1);
}