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use futures::channel::mpsc;
use futures::executor::block_on;
use futures::future::poll_fn;
use futures::sink::SinkExt;
use futures::stream::StreamExt;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::thread;
#[test]
fn sequence() {
let (tx, rx) = mpsc::channel(1);
let amt = 20;
let t = thread::spawn(move || block_on(send_sequence(amt, tx)));
let list: Vec<_> = block_on(rx.collect());
let mut list = list.into_iter();
for i in (1..=amt).rev() {
assert_eq!(list.next(), Some(i));
}
assert_eq!(list.next(), None);
t.join().unwrap();
}
async fn send_sequence(n: u32, mut sender: mpsc::Sender<u32>) {
for x in 0..n {
sender.send(n - x).await.unwrap();
}
}
#[test]
fn drop_sender() {
let (tx, mut rx) = mpsc::channel::<u32>(1);
drop(tx);
let f = poll_fn(|cx| rx.poll_next_unpin(cx));
assert_eq!(block_on(f), None)
}
#[test]
fn drop_rx() {
let (mut tx, rx) = mpsc::channel::<u32>(1);
block_on(tx.send(1)).unwrap();
drop(rx);
assert!(block_on(tx.send(1)).is_err());
}
#[test]
fn drop_order() {
static DROPS: AtomicUsize = AtomicUsize::new(0);
let (mut tx, rx) = mpsc::channel(1);
struct A;
impl Drop for A {
fn drop(&mut self) {
DROPS.fetch_add(1, Ordering::SeqCst);
}
}
block_on(tx.send(A)).unwrap();
assert_eq!(DROPS.load(Ordering::SeqCst), 0);
drop(rx);
assert_eq!(DROPS.load(Ordering::SeqCst), 1);
assert!(block_on(tx.send(A)).is_err());
assert_eq!(DROPS.load(Ordering::SeqCst), 2);
}