1 #![warn(rust_2018_idioms)]
2 #![cfg(feature = "full")]
3
4 use std::time::Duration;
5 use tokio::io::{self, copy_bidirectional, AsyncReadExt, AsyncWriteExt};
6 use tokio::net::TcpStream;
7 use tokio::task::JoinHandle;
8
make_socketpair() -> (TcpStream, TcpStream)9 async fn make_socketpair() -> (TcpStream, TcpStream) {
10 let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
11 let addr = listener.local_addr().unwrap();
12 let connector = TcpStream::connect(addr);
13 let acceptor = listener.accept();
14
15 let (c1, c2) = tokio::join!(connector, acceptor);
16
17 (c1.unwrap(), c2.unwrap().0)
18 }
19
block_write(s: &mut TcpStream) -> usize20 async fn block_write(s: &mut TcpStream) -> usize {
21 static BUF: [u8; 2048] = [0; 2048];
22
23 let mut copied = 0;
24 loop {
25 tokio::select! {
26 result = s.write(&BUF) => {
27 copied += result.expect("write error")
28 },
29 _ = tokio::time::sleep(Duration::from_millis(10)) => {
30 break;
31 }
32 }
33 }
34
35 copied
36 }
37
symmetric<F, Fut>(mut cb: F) where F: FnMut(JoinHandle<io::Result<(u64, u64)>>, TcpStream, TcpStream) -> Fut, Fut: std::future::Future<Output = ()>,38 async fn symmetric<F, Fut>(mut cb: F)
39 where
40 F: FnMut(JoinHandle<io::Result<(u64, u64)>>, TcpStream, TcpStream) -> Fut,
41 Fut: std::future::Future<Output = ()>,
42 {
43 // We run the test twice, with streams passed to copy_bidirectional in
44 // different orders, in order to ensure that the two arguments are
45 // interchangeable.
46
47 let (a, mut a1) = make_socketpair().await;
48 let (b, mut b1) = make_socketpair().await;
49
50 let handle = tokio::spawn(async move { copy_bidirectional(&mut a1, &mut b1).await });
51 cb(handle, a, b).await;
52
53 let (a, mut a1) = make_socketpair().await;
54 let (b, mut b1) = make_socketpair().await;
55
56 let handle = tokio::spawn(async move { copy_bidirectional(&mut b1, &mut a1).await });
57
58 cb(handle, b, a).await;
59 }
60
61 #[tokio::test]
test_basic_transfer()62 async fn test_basic_transfer() {
63 symmetric(|_handle, mut a, mut b| async move {
64 a.write_all(b"test").await.unwrap();
65 let mut tmp = [0; 4];
66 b.read_exact(&mut tmp).await.unwrap();
67 assert_eq!(&tmp[..], b"test");
68 })
69 .await
70 }
71
72 #[tokio::test]
test_transfer_after_close()73 async fn test_transfer_after_close() {
74 symmetric(|handle, mut a, mut b| async move {
75 AsyncWriteExt::shutdown(&mut a).await.unwrap();
76 b.read_to_end(&mut Vec::new()).await.unwrap();
77
78 b.write_all(b"quux").await.unwrap();
79 let mut tmp = [0; 4];
80 a.read_exact(&mut tmp).await.unwrap();
81 assert_eq!(&tmp[..], b"quux");
82
83 // Once both are closed, we should have our handle back
84 drop(b);
85
86 assert_eq!(handle.await.unwrap().unwrap(), (0, 4));
87 })
88 .await
89 }
90
91 #[tokio::test]
blocking_one_side_does_not_block_other()92 async fn blocking_one_side_does_not_block_other() {
93 symmetric(|handle, mut a, mut b| async move {
94 block_write(&mut a).await;
95
96 b.write_all(b"quux").await.unwrap();
97 let mut tmp = [0; 4];
98 a.read_exact(&mut tmp).await.unwrap();
99 assert_eq!(&tmp[..], b"quux");
100
101 AsyncWriteExt::shutdown(&mut a).await.unwrap();
102
103 let mut buf = Vec::new();
104 b.read_to_end(&mut buf).await.unwrap();
105
106 drop(b);
107
108 assert_eq!(handle.await.unwrap().unwrap(), (buf.len() as u64, 4));
109 })
110 .await
111 }
112
113 #[tokio::test]
immediate_exit_on_error()114 async fn immediate_exit_on_error() {
115 symmetric(|handle, mut a, mut b| async move {
116 block_write(&mut a).await;
117
118 // Fill up the b->copy->a path. We expect that this will _not_ drain
119 // before we exit the copy task.
120 let _bytes_written = block_write(&mut b).await;
121
122 // Drop b. We should not wait for a to consume the data buffered in the
123 // copy loop, since b will be failing writes.
124 drop(b);
125 assert!(handle.await.unwrap().is_err());
126 })
127 .await
128 }
129