From 4320c6739eeb91270cd2ea33c5d0a1cf0ff694e1 Mon Sep 17 00:00:00 2001
From: daxpedda <daxpedda@gmail.com>
Date: Wed, 22 Mar 2023 16:53:54 +0100
Subject: [PATCH] Use `Waker::will_wake()` to avoid a cloning op (#12)

---
 src/lib.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index 8cf68cd..54f4726 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -285,7 +285,12 @@ impl AtomicWaker {
             WAITING => {
                 unsafe {
                     // Locked acquired, update the waker cell
-                    *self.waker.get() = Some(waker.clone());
+
+                    // Avoid cloning the waker if the old waker will awaken the same task.
+                    match &*self.waker.get() {
+                        Some(old_waker) if old_waker.will_wake(waker) => (),
+                        _ => *self.waker.get() = Some(waker.clone()),
+                    }
 
                     // Release the lock. If the state transitioned to include
                     // the `WAKING` bit, this means that at least one wake has