#![warn(rust_2018_idioms)] #![cfg(feature = "full")] 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(100)) => { break; } } } copied } async fn symmetric(mut cb: F) where F: FnMut(JoinHandle>, TcpStream, TcpStream) -> Fut, Fut: std::future::Future, { // 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] 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] 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] 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_error() { symmetric(|handle, mut a, mut b| async move { block_write(&mut a).await; // Fill up the b->copy->a path. We expect that this will _not_ drain // before we exit the copy task. let _bytes_written = block_write(&mut b).await; // Drop b. We should not wait for a to consume the data buffered in the // copy loop, since b will be failing writes. drop(b); assert!(handle.await.unwrap().is_err()); }) .await }