blob: f16a99eafb82ec8d60ce7d46178468b8ffd625b6 (
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
|
use smol::lock::Mutex;
use super::CondVar;
/// CondWait is a wrapper struct for CondVar with a Mutex boolean flag.
///
/// # Example
///
///```
/// use std::sync::Arc;
///
/// use karyons_core::async_utils::CondWait;
///
/// async {
/// let cond_wait = Arc::new(CondWait::new());
/// let cond_wait_cloned = cond_wait.clone();
/// let task = smol::spawn(async move {
/// cond_wait_cloned.wait().await;
/// // ...
/// });
///
/// cond_wait.signal().await;
/// };
///
/// ```
///
pub struct CondWait {
/// The CondVar
condvar: CondVar,
/// Boolean flag
w: Mutex<bool>,
}
impl CondWait {
/// Creates a new CondWait.
pub fn new() -> Self {
Self {
condvar: CondVar::new(),
w: Mutex::new(false),
}
}
/// Waits for a signal or broadcast.
pub async fn wait(&self) {
let mut w = self.w.lock().await;
// While the boolean flag is false, wait for a signal.
while !*w {
w = self.condvar.wait(w).await;
}
}
/// Signal a waiting task.
pub async fn signal(&self) {
*self.w.lock().await = true;
self.condvar.signal();
}
/// Signal all waiting tasks.
pub async fn broadcast(&self) {
*self.w.lock().await = true;
self.condvar.broadcast();
}
/// Reset the boolean flag value to false.
pub async fn reset(&self) {
*self.w.lock().await = false;
}
}
impl Default for CondWait {
fn default() -> Self {
Self::new()
}
}
#[cfg(test)]
mod tests {
use super::*;
use std::sync::Arc;
#[test]
fn test_cond_wait() {
smol::block_on(async {
let cond_wait = Arc::new(CondWait::new());
let cond_wait_cloned = cond_wait.clone();
let task = smol::spawn(async move {
cond_wait_cloned.wait().await;
true
});
cond_wait.signal().await;
assert!(task.await);
});
}
}
|