From ed256361417ceaf6693f76a32675397055eda147 Mon Sep 17 00:00:00 2001
From: Minh Vu <vuhoangminh97@gmail.com>
Date: Sun, 9 Aug 2026 16:45:35 +0200
Subject: [PATCH] time: wake `DelayQueue` when cleared (#8320)

---
 tokio-util/src/time/delay_queue.rs   |  8 ++++++++
 tokio-util/tests/time_delay_queue.rs | 14 ++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/tokio-util/src/time/delay_queue.rs b/tokio-util/src/time/delay_queue.rs
index 3c7d65ed4..b53d18046 100644
--- a/tokio-util/src/time/delay_queue.rs
+++ b/tokio-util/src/time/delay_queue.rs
@@ -1031,10 +1031,18 @@ impl<T> DelayQueue<T> {
     /// # }
     /// ```
     pub fn clear(&mut self) {
+        let had_entries = !self.slab.is_empty();
+
         self.slab.clear();
         self.expired = Stack::default();
         self.wheel = Wheel::new();
         self.delay = None;
+
+        if had_entries {
+            if let Some(waker) = self.waker.take() {
+                waker.wake();
+            }
+        }
     }
 
     /// Returns the number of elements the queue can hold without reallocating.
diff --git a/tokio-util/tests/time_delay_queue.rs b/tokio-util/tests/time_delay_queue.rs
index 74360b39e..a2db75c00 100644
--- a/tokio-util/tests/time_delay_queue.rs
+++ b/tokio-util/tests/time_delay_queue.rs
@@ -915,6 +915,20 @@ async fn wake_after_remove_last() {
     assert!(assert_ready!(poll!(queue)).is_none());
 }
 
+#[tokio::test(start_paused = true)]
+async fn wake_after_clear() {
+    let mut queue = task::spawn(DelayQueue::new());
+    queue.insert("foo", ms(1000));
+
+    assert_pending!(poll!(queue));
+    assert!(!queue.is_woken());
+
+    queue.clear();
+
+    assert!(queue.is_woken());
+    assert!(assert_ready!(poll!(queue)).is_none());
+}
+
 fn ms(n: u64) -> Duration {
     Duration::from_millis(n)
 }