2 files changed, 32 insertions, 5 deletions

diff --git a/embassy-executor/Cargo.toml b/embassy-executor/Cargo.toml
index 0ea18acbc..01c028704 100644
--- a/embassy-executor/Cargo.toml
+++ b/embassy-executor/Cargo.toml
@@ -78,10 +78,8 @@ avr-device = { version = "0.7.0", optional = true }
 
 
 [dependencies.cordyceps]
-# version = "0.3.3"
-# todo: update after https://github.com/hawkw/mycelium/pull/537 is merged
-git = "https://github.com/hawkw/mycelium"
-rev = "e21f9756e7d787a023f2ef1bc7f2159cc7dd26e0"
+version = "0.3.4"
+features = ["no-cache-pad"]
 
 # Note: this is ONLY a dependency when the target does NOT have atomics
 [target.'cfg(not(target_has_atomic="ptr"))'.dependencies.mutex]
diff --git a/embassy-executor/src/raw/run_queue.rs b/embassy-executor/src/raw/run_queue.rs
index c6c7d7109..5fd703aad 100644
--- a/embassy-executor/src/raw/run_queue.rs
+++ b/embassy-executor/src/raw/run_queue.rs
@@ -9,7 +9,7 @@ use cordyceps::SortedList;
 type TransferStack<T> = cordyceps::TransferStack<T>;
 
 #[cfg(not(target_has_atomic = "ptr"))]
-type TransferStack<T> = cordyceps::MutexTransferStack<mutex::raw_impls::cs::CriticalSectionRawMutex, T>;
+type TransferStack<T> = MutexTransferStack<T>;
 
 use super::{TaskHeader, TaskRef};
 
@@ -149,3 +149,32 @@ fn run_dequeue(taskref: &TaskRef) {
         taskref.header().state.run_dequeue(cs);
     })
 }
+
+/// A wrapper type that acts like TransferStack by wrapping a normal Stack in a CS mutex
+#[cfg(not(target_has_atomic="ptr"))]
+struct MutexTransferStack<T: Linked<cordyceps::stack::Links<T>>> {
+    inner: mutex::BlockingMutex<mutex::raw_impls::cs::CriticalSectionRawMutex, cordyceps::Stack<T>>,
+}
+
+#[cfg(not(target_has_atomic="ptr"))]
+impl<T: Linked<cordyceps::stack::Links<T>>> MutexTransferStack<T> {
+    const fn new() -> Self {
+        Self {
+            inner: mutex::BlockingMutex::new(cordyceps::Stack::new()),
+        }
+    }
+
+    fn push_was_empty(&self, item: T::Handle) -> bool {
+        self.inner.with_lock(|stack| {
+            let is_empty = stack.is_empty();
+            stack.push(item);
+            is_empty
+        })
+    }
+
+    fn take_all(&self) -> cordyceps::Stack<T> {
+        self.inner.with_lock(|stack| {
+            stack.take_all()
+        })
+    }
+}