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#![warn(rust_2018_idioms)]
#![cfg(all(feature = "full", not(target_os = "wasi")))] // Wasi does not support bind()
use std::time::Duration;
use tokio::io::{self, copy_bidirectional, AsyncReadExt, AsyncWriteExt};
use tokio::net::TcpStream;
use tokio::task::JoinHandle;
async fn make_socketpair() -> (TcpStream, TcpStream) {
let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
let addr = listener.local_addr().unwrap();
let connector = TcpStream::connect(addr);
let acceptor = listener.accept();
let (c1, c2) = tokio::join!(connector, acceptor);
(c1.unwrap(), c2.unwrap().0)
}
async fn block_write(s: &mut TcpStream) -> usize {
static BUF: [u8; 2048] = [0; 2048];
let mut copied = 0;
loop {
tokio::select! {
result = s.write(&BUF) => {
copied += result.expect("write error")
},
_ = tokio::time::sleep(Duration::from_millis(10)) => {
break;
}
}
}
copied
}
async fn symmetric<F, Fut>(mut cb: F)
where
F: FnMut(JoinHandle<io::Result<(u64, u64)>>, TcpStream, TcpStream) -> Fut,
Fut: std::future::Future<Output = ()>,
{
// We run the test twice, with streams passed to copy_bidirectional in
// different orders, in order to ensure that the two arguments are
// interchangeable.
let (a, mut a1) = make_socketpair().await;
let (b, mut b1) = make_socketpair().await;
let handle = tokio::spawn(async move { copy_bidirectional(&mut a1, &mut b1).await });
cb(handle, a, b).await;
let (a, mut a1) = make_socketpair().await;
let (b, mut b1) = make_socketpair().await;
let handle = tokio::spawn(async move { copy_bidirectional(&mut b1, &mut a1).await });
cb(handle, b, a).await;
}
#[tokio::test]
#[cfg_attr(miri, ignore)] // No `socket` in miri.
async fn test_basic_transfer() {
symmetric(|_handle, mut a, mut b| async move {
a.write_all(b"test").await.unwrap();
let mut tmp = [0; 4];
b.read_exact(&mut tmp).await.unwrap();
assert_eq!(&tmp[..], b"test");
})
.await
}
#[tokio::test]
#[cfg_attr(miri, ignore)] // No `socket` in miri.
async fn test_transfer_after_close() {
symmetric(|handle, mut a, mut b| async move {
AsyncWriteExt::shutdown(&mut a).await.unwrap();
b.read_to_end(&mut Vec::new()).await.unwrap();
b.write_all(b"quux").await.unwrap();
let mut tmp = [0; 4];
a.read_exact(&mut tmp).await.unwrap();
assert_eq!(&tmp[..], b"quux");
// Once both are closed, we should have our handle back
drop(b);
assert_eq!(handle.await.unwrap().unwrap(), (0, 4));
})
.await
}
#[tokio::test]
#[cfg_attr(miri, ignore)] // No `socket` in miri.
async fn blocking_one_side_does_not_block_other() {
symmetric(|handle, mut a, mut b| async move {
block_write(&mut a).await;
b.write_all(b"quux").await.unwrap();
let mut tmp = [0; 4];
a.read_exact(&mut tmp).await.unwrap();
assert_eq!(&tmp[..], b"quux");
AsyncWriteExt::shutdown(&mut a).await.unwrap();
let mut buf = Vec::new();
b.read_to_end(&mut buf).await.unwrap();
drop(b);
assert_eq!(handle.await.unwrap().unwrap(), (buf.len() as u64, 4));
})
.await
}
#[tokio::test]
async fn immediate_exit_on_write_error() {
let payload = b"here, take this";
let error = || io::Error::new(io::ErrorKind::Other, "no thanks!");
let mut a = tokio_test::io::Builder::new()
.read(payload)
.write_error(error())
.build();
let mut b = tokio_test::io::Builder::new()
.read(payload)
.write_error(error())
.build();
assert!(copy_bidirectional(&mut a, &mut b).await.is_err());
}
#[tokio::test]
async fn immediate_exit_on_read_error() {
let error = || io::Error::new(io::ErrorKind::Other, "got nothing!");
let mut a = tokio_test::io::Builder::new().read_error(error()).build();
let mut b = tokio_test::io::Builder::new().read_error(error()).build();
assert!(copy_bidirectional(&mut a, &mut b).await.is_err());
}
#[tokio::test]
async fn copy_bidirectional_is_cooperative() {
tokio::select! {
biased;
_ = async {
loop {
let payload = b"here, take this";
let mut a = tokio_test::io::Builder::new()
.read(payload)
.write(payload)
.build();
let mut b = tokio_test::io::Builder::new()
.read(payload)
.write(payload)
.build();
let _ = copy_bidirectional(&mut a, &mut b).await;
}
} => {},
_ = tokio::task::yield_now() => {}
}
}
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