1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
#![warn(rust_2018_idioms)]
#![cfg(all(feature = "full", not(tokio_wasi)))] // Wasi doesn't support bind
use tokio::net::{TcpListener, TcpStream};
use tokio::sync::{mpsc, oneshot};
use tokio_test::assert_ok;
use std::io;
use std::net::{IpAddr, SocketAddr};
macro_rules! test_accept {
($(($ident:ident, $target:expr),)*) => {
$(
#[tokio::test]
async fn $ident() {
let listener = assert_ok!(TcpListener::bind($target).await);
let addr = listener.local_addr().unwrap();
let (tx, rx) = oneshot::channel();
tokio::spawn(async move {
let (socket, _) = assert_ok!(listener.accept().await);
assert_ok!(tx.send(socket));
});
let cli = assert_ok!(TcpStream::connect(&addr).await);
let srv = assert_ok!(rx.await);
assert_eq!(cli.local_addr().unwrap(), srv.peer_addr().unwrap());
}
)*
}
}
test_accept! {
(ip_str, "127.0.0.1:0"),
(host_str, "localhost:0"),
(socket_addr, "127.0.0.1:0".parse::<SocketAddr>().unwrap()),
(str_port_tuple, ("127.0.0.1", 0)),
(ip_port_tuple, ("127.0.0.1".parse::<IpAddr>().unwrap(), 0)),
}
use std::pin::Pin;
use std::sync::{
atomic::{AtomicUsize, Ordering::SeqCst},
Arc,
};
use std::task::{Context, Poll};
use tokio_stream::{Stream, StreamExt};
struct TrackPolls<'a> {
npolls: Arc<AtomicUsize>,
listener: &'a mut TcpListener,
}
impl<'a> Stream for TrackPolls<'a> {
type Item = io::Result<(TcpStream, SocketAddr)>;
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
self.npolls.fetch_add(1, SeqCst);
self.listener.poll_accept(cx).map(Some)
}
}
#[tokio::test]
async fn no_extra_poll() {
let mut listener = assert_ok!(TcpListener::bind("127.0.0.1:0").await);
let addr = listener.local_addr().unwrap();
let (tx, rx) = oneshot::channel();
let (accepted_tx, mut accepted_rx) = mpsc::unbounded_channel();
tokio::spawn(async move {
let mut incoming = TrackPolls {
npolls: Arc::new(AtomicUsize::new(0)),
listener: &mut listener,
};
assert_ok!(tx.send(Arc::clone(&incoming.npolls)));
while incoming.next().await.is_some() {
accepted_tx.send(()).unwrap();
}
});
let npolls = assert_ok!(rx.await);
tokio::task::yield_now().await;
// should have been polled exactly once: the initial poll
assert_eq!(npolls.load(SeqCst), 1);
let _ = assert_ok!(TcpStream::connect(&addr).await);
accepted_rx.recv().await.unwrap();
// should have been polled twice more: once to yield Some(), then once to yield Pending
assert_eq!(npolls.load(SeqCst), 1 + 2);
}
#[tokio::test]
async fn accept_many() {
use futures::future::poll_fn;
use std::future::Future;
use std::sync::atomic::AtomicBool;
const N: usize = 50;
let listener = assert_ok!(TcpListener::bind("127.0.0.1:0").await);
let listener = Arc::new(listener);
let addr = listener.local_addr().unwrap();
let connected = Arc::new(AtomicBool::new(false));
let (pending_tx, mut pending_rx) = mpsc::unbounded_channel();
let (notified_tx, mut notified_rx) = mpsc::unbounded_channel();
for _ in 0..N {
let listener = listener.clone();
let connected = connected.clone();
let pending_tx = pending_tx.clone();
let notified_tx = notified_tx.clone();
tokio::spawn(async move {
let accept = listener.accept();
tokio::pin!(accept);
let mut polled = false;
poll_fn(|cx| {
if !polled {
polled = true;
assert!(Pin::new(&mut accept).poll(cx).is_pending());
pending_tx.send(()).unwrap();
Poll::Pending
} else if connected.load(SeqCst) {
notified_tx.send(()).unwrap();
Poll::Ready(())
} else {
Poll::Pending
}
})
.await;
pending_tx.send(()).unwrap();
});
}
// Wait for all tasks to have polled at least once
for _ in 0..N {
pending_rx.recv().await.unwrap();
}
// Establish a TCP connection
connected.store(true, SeqCst);
let _sock = TcpStream::connect(addr).await.unwrap();
// Wait for all notifications
for _ in 0..N {
notified_rx.recv().await.unwrap();
}
}
|
