summaryrefslogtreecommitdiffstats
path: root/tokio/tests/sync_oneshot.rs
blob: 195c25531455d7adf5346c894945cd6f70d35467 (plain)
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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
#![warn(rust_2018_idioms)]
#![cfg(feature = "full")]

use tokio::sync::oneshot;
use tokio_test::*;

use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};

trait AssertSend: Send {}
impl AssertSend for oneshot::Sender<i32> {}
impl AssertSend for oneshot::Receiver<i32> {}

trait SenderExt {
    fn poll_closed(&mut self, cx: &mut Context<'_>) -> Poll<()>;
}
impl<T> SenderExt for oneshot::Sender<T> {
    fn poll_closed(&mut self, cx: &mut Context<'_>) -> Poll<()> {
        tokio::pin! {
            let fut = self.closed();
        }
        fut.poll(cx)
    }
}

#[test]
fn send_recv() {
    let (tx, rx) = oneshot::channel();
    let mut rx = task::spawn(rx);

    assert_pending!(rx.poll());

    assert_ok!(tx.send(1));

    assert!(rx.is_woken());

    let val = assert_ready_ok!(rx.poll());
    assert_eq!(val, 1);
}

#[tokio::test]
async fn async_send_recv() {
    let (tx, rx) = oneshot::channel();

    assert_ok!(tx.send(1));
    assert_eq!(1, assert_ok!(rx.await));
}

#[test]
fn close_tx() {
    let (tx, rx) = oneshot::channel::<i32>();
    let mut rx = task::spawn(rx);

    assert_pending!(rx.poll());

    drop(tx);

    assert!(rx.is_woken());
    assert_ready_err!(rx.poll());
}

#[test]
fn close_rx() {
    // First, without checking poll_closed()
    //
    let (tx, _) = oneshot::channel();

    assert_err!(tx.send(1));

    // Second, via poll_closed();

    let (tx, rx) = oneshot::channel();
    let mut tx = task::spawn(tx);

    assert_pending!(tx.enter(|cx, mut tx| tx.poll_closed(cx)));

    drop(rx);

    assert!(tx.is_woken());
    assert!(tx.is_closed());
    assert_ready!(tx.enter(|cx, mut tx| tx.poll_closed(cx)));

    assert_err!(tx.into_inner().send(1));
}

#[tokio::test]
async fn async_rx_closed() {
    let (mut tx, rx) = oneshot::channel::<()>();

    tokio::spawn(async move {
        drop(rx);
    });

    tx.closed().await;
}

#[test]
fn explicit_close_poll() {
    // First, with message sent
    let (tx, rx) = oneshot::channel();
    let mut rx = task::spawn(rx);

    assert_ok!(tx.send(1));

    rx.close();

    let value = assert_ready_ok!(rx.poll());
    assert_eq!(value, 1);

    // Second, without the message sent
    let (tx, rx) = oneshot::channel::<i32>();
    let mut tx = task::spawn(tx);
    let mut rx = task::spawn(rx);

    assert_pending!(tx.enter(|cx, mut tx| tx.poll_closed(cx)));

    rx.close();

    assert!(tx.is_woken());
    assert!(tx.is_closed());
    assert_ready!(tx.enter(|cx, mut tx| tx.poll_closed(cx)));

    assert_err!(tx.into_inner().send(1));
    assert_ready_err!(rx.poll());

    // Again, but without sending the value this time
    let (tx, rx) = oneshot::channel::<i32>();
    let mut tx = task::spawn(tx);
    let mut rx = task::spawn(rx);

    assert_pending!(tx.enter(|cx, mut tx| tx.poll_closed(cx)));

    rx.close();

    assert!(tx.is_woken());
    assert!(tx.is_closed());
    assert_ready!(tx.enter(|cx, mut tx| tx.poll_closed(cx)));

    assert_ready_err!(rx.poll());
}

#[test]
fn explicit_close_try_recv() {
    // First, with message sent
    let (tx, mut rx) = oneshot::channel();

    assert_ok!(tx.send(1));

    rx.close();

    let val = assert_ok!(rx.try_recv());
    assert_eq!(1, val);

    // Second, without the message sent
    let (tx, mut rx) = oneshot::channel::<i32>();
    let mut tx = task::spawn(tx);

    assert_pending!(tx.enter(|cx, mut tx| tx.poll_closed(cx)));

    rx.close();

    assert!(tx.is_woken());
    assert!(tx.is_closed());
    assert_ready!(tx.enter(|cx, mut tx| tx.poll_closed(cx)));

    assert_err!(rx.try_recv());
}

#[test]
#[should_panic]
fn close_try_recv_poll() {
    let (_tx, rx) = oneshot::channel::<i32>();
    let mut rx = task::spawn(rx);

    rx.close();

    assert_err!(rx.try_recv());

    let _ = rx.poll();
}

#[test]
fn drops_tasks() {
    let (mut tx, mut rx) = oneshot::channel::<i32>();
    let mut tx_task = task::spawn(());
    let mut rx_task = task::spawn(());

    assert_pending!(tx_task.enter(|cx, _| tx.poll_closed(cx)));
    assert_pending!(rx_task.enter(|cx, _| Pin::new(&mut rx).poll(cx)));

    drop(tx);
    drop(rx);

    assert_eq!(1, tx_task.waker_ref_count());
    assert_eq!(1, rx_task.waker_ref_count());
}

#[test]
fn receiver_changes_task() {
    let (tx, mut rx) = oneshot::channel();

    let mut task1 = task::spawn(());
    let mut task2 = task::spawn(());

    assert_pending!(task1.enter(|cx, _| Pin::new(&mut rx).poll(cx)));

    assert_eq!(2, task1.waker_ref_count());
    assert_eq!(1, task2.waker_ref_count());

    assert_pending!(task2.enter(|cx, _| Pin::new(&mut rx).poll(cx)));

    assert_eq!(1, task1.waker_ref_count());
    assert_eq!(2, task2.waker_ref_count());

    assert_ok!(tx.send(1));

    assert!(!task1.is_woken());
    assert!(task2.is_woken());

    assert_ready_ok!(task2.enter(|cx, _| Pin::new(&mut rx).poll(cx)));
}

#[test]
fn sender_changes_task() {
    let (mut tx, rx) = oneshot::channel::<i32>();

    let mut task1 = task::spawn(());
    let mut task2 = task::spawn(());

    assert_pending!(task1.enter(|cx, _| tx.poll_closed(cx)));

    assert_eq!(2, task1.waker_ref_count());
    assert_eq!(1, task2.waker_ref_count());

    assert_pending!(task2.enter(|cx, _| tx.poll_closed(cx)));

    assert_eq!(1, task1.waker_ref_count());
    assert_eq!(2, task2.waker_ref_count());

    drop(rx);

    assert!(!task1.is_woken());
    assert!(task2.is_woken());

    assert_ready!(task2.enter(|cx, _| tx.poll_closed(cx)));
}