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authorhozan23 <hozan23@proton.me>2023-11-08 13:03:27 +0300
committerhozan23 <hozan23@proton.me>2023-11-08 13:03:27 +0300
commit4fe665fc8bc6265baf5bfba6b6a5f3ee2dba63dc (patch)
tree77c7c40c9725539546e53b00f424deafe5ec81a8 /karyons_core/src/async_utils/condwait.rs
first commit
Diffstat (limited to 'karyons_core/src/async_utils/condwait.rs')
-rw-r--r--karyons_core/src/async_utils/condwait.rs96
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diff --git a/karyons_core/src/async_utils/condwait.rs b/karyons_core/src/async_utils/condwait.rs
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+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);
+ });
+ }
+}