AtomicWaker: take and wake

embassy-executor/tests/test.rs

@@ -156,8 +156,7 @@ fn waking_after_completion_does_not_poll() {
     let (executor, trace) = setup();
     executor.spawner().spawn(task1(trace.clone(), waker)).unwrap();
 
-    unsafe { executor.poll() };
-    waker.wake();
+    // Task registers waker, then exits
     unsafe { executor.poll() };
 
     // Exited task may be waken but is not polled
@@ -176,7 +175,6 @@ fn waking_after_completion_does_not_poll() {
             "pend",       // spawning a task pends the executor
             "poll task1", //
             "pend",       // manual wake, gets cleared by poll
-            "pend",       // manual wake, single pend for two wakes
             "pend",       // respawning a task pends the executor
             "poll task1", //
         ]

embassy-sync/CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+- AtomicWaker now drops the Waker after waking it.
+
 ## 0.6.2 - 2025-01-15
 
 - Add dynamic dispatch variant of `Pipe`.

embassy-sync/src/waitqueue/atomic_waker.rs

@@ -32,12 +32,9 @@ impl<M: RawMutex> GenericAtomicWaker<M> {
 
     /// Wake the registered waker, if any.
     pub fn wake(&self) {
-        self.waker.lock(|cell| {
-            if let Some(w) = cell.replace(None) {
-                w.wake_by_ref();
-                cell.set(Some(w));
-            }
-        })
+        if let Some(waker) = self.waker.lock(|cell| cell.take()) {
+            waker.wake();
+        }
     }
 }