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#![warn(rust_2018_idioms)]
#![cfg(feature = "full")]
use tokio::io::{duplex, AsyncReadExt, AsyncWriteExt};
#[tokio::test]
async fn ping_pong() {
let (mut a, mut b) = duplex(32);
let mut buf = [0u8; 4];
a.write_all(b"ping").await.unwrap();
b.read_exact(&mut buf).await.unwrap();
assert_eq!(&buf, b"ping");
b.write_all(b"pong").await.unwrap();
a.read_exact(&mut buf).await.unwrap();
assert_eq!(&buf, b"pong");
}
#[tokio::test]
async fn across_tasks() {
let (mut a, mut b) = duplex(32);
let t1 = tokio::spawn(async move {
a.write_all(b"ping").await.unwrap();
let mut buf = [0u8; 4];
a.read_exact(&mut buf).await.unwrap();
assert_eq!(&buf, b"pong");
});
let t2 = tokio::spawn(async move {
let mut buf = [0u8; 4];
b.read_exact(&mut buf).await.unwrap();
assert_eq!(&buf, b"ping");
b.write_all(b"pong").await.unwrap();
});
t1.await.unwrap();
t2.await.unwrap();
}
#[tokio::test]
async fn disconnect() {
let (mut a, mut b) = duplex(32);
let t1 = tokio::spawn(async move {
a.write_all(b"ping").await.unwrap();
// and dropped
});
let t2 = tokio::spawn(async move {
let mut buf = [0u8; 32];
let n = b.read(&mut buf).await.unwrap();
assert_eq!(&buf[..n], b"ping");
let n = b.read(&mut buf).await.unwrap();
assert_eq!(n, 0);
});
t1.await.unwrap();
t2.await.unwrap();
}
#[tokio::test]
async fn disconnect_reader() {
let (a, mut b) = duplex(2);
let t1 = tokio::spawn(async move {
// this will block, as not all data fits into duplex
b.write_all(b"ping").await.unwrap_err();
});
let t2 = tokio::spawn(async move {
// here we drop the reader side, and we expect the writer in the other
// task to exit with an error
drop(a);
});
t2.await.unwrap();
t1.await.unwrap();
}
#[tokio::test]
async fn max_write_size() {
let (mut a, mut b) = duplex(32);
let t1 = tokio::spawn(async move {
let n = a.write(&[0u8; 64]).await.unwrap();
assert_eq!(n, 32);
let n = a.write(&[0u8; 64]).await.unwrap();
assert_eq!(n, 4);
});
let mut buf = [0u8; 4];
b.read_exact(&mut buf).await.unwrap();
t1.await.unwrap();
// drop b only after task t1 finishes writing
drop(b);
}
#[tokio::test]
async fn duplex_is_cooperative() {
let (mut tx, mut rx) = tokio::io::duplex(1024 * 8);
tokio::select! {
biased;
_ = async {
loop {
let buf = [3u8; 4096];
tx.write_all(&buf).await.unwrap();
let mut buf = [0u8; 4096];
let _ = rx.read(&mut buf).await.unwrap();
}
} => {},
_ = tokio::task::yield_now() => {}
}
}