2 files changed, 41 insertions, 61 deletions

diff --git a/embassy-sync/src/channel.rs b/embassy-sync/src/channel.rs
index a512e0c41..aa267471c 100644
--- a/embassy-sync/src/channel.rs
+++ b/embassy-sync/src/channel.rs
@@ -321,7 +321,7 @@ impl<'ch, T> Future for DynamicSendFuture<'ch, T> {
 
 impl<'ch, T> Unpin for DynamicSendFuture<'ch, T> {}
 
-trait DynamicChannel<T> {
+pub(crate) trait DynamicChannel<T> {
     fn try_send_with_context(&self, message: T, cx: Option<&mut Context<'_>>) -> Result<(), TrySendError<T>>;
 
     fn try_receive_with_context(&self, cx: Option<&mut Context<'_>>) -> Result<T, TryReceiveError>;
diff --git a/embassy-sync/src/priority_channel.rs b/embassy-sync/src/priority_channel.rs
index 04148b56f..13c407c21 100644
--- a/embassy-sync/src/priority_channel.rs
+++ b/embassy-sync/src/priority_channel.rs
@@ -7,17 +7,19 @@ use core::future::Future;
 use core::pin::Pin;
 use core::task::{Context, Poll};
 
+use heapless::binary_heap::Kind;
 use heapless::BinaryHeap;
 
 use crate::blocking_mutex::raw::RawMutex;
 use crate::blocking_mutex::Mutex;
+use crate::channel::{DynamicChannel, TryReceiveError, TrySendError};
 use crate::waitqueue::WakerRegistration;
 
 /// Send-only access to a [`PriorityChannel`].
 pub struct Sender<'ch, M, T, K, const N: usize>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     channel: &'ch PriorityChannel<M, T, K, N>,
@@ -26,7 +28,7 @@ where
 impl<'ch, M, T, K, const N: usize> Clone for Sender<'ch, M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     fn clone(&self) -> Self {
@@ -37,7 +39,7 @@ where
 impl<'ch, M, T, K, const N: usize> Copy for Sender<'ch, M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
 }
@@ -45,7 +47,7 @@ where
 impl<'ch, M, T, K, const N: usize> Sender<'ch, M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     /// Sends a value.
@@ -86,7 +88,7 @@ impl<'ch, T> Copy for DynamicSender<'ch, T> {}
 impl<'ch, M, T, K, const N: usize> From<Sender<'ch, M, T, K, N>> for DynamicSender<'ch, T>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     fn from(s: Sender<'ch, M, T, K, N>) -> Self {
@@ -124,7 +126,7 @@ impl<'ch, T> DynamicSender<'ch, T> {
 pub struct Receiver<'ch, M, T, K, const N: usize>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     channel: &'ch PriorityChannel<M, T, K, N>,
@@ -133,7 +135,7 @@ where
 impl<'ch, M, T, K, const N: usize> Clone for Receiver<'ch, M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     fn clone(&self) -> Self {
@@ -144,7 +146,7 @@ where
 impl<'ch, M, T, K, const N: usize> Copy for Receiver<'ch, M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
 }
@@ -152,7 +154,7 @@ where
 impl<'ch, M, T, K, const N: usize> Receiver<'ch, M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     /// Receive the next value.
@@ -230,7 +232,7 @@ impl<'ch, T> DynamicReceiver<'ch, T> {
 impl<'ch, M, T, K, const N: usize> From<Receiver<'ch, M, T, K, N>> for DynamicReceiver<'ch, T>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     fn from(s: Receiver<'ch, M, T, K, N>) -> Self {
@@ -243,7 +245,7 @@ where
 pub struct ReceiveFuture<'ch, M, T, K, const N: usize>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     channel: &'ch PriorityChannel<M, T, K, N>,
@@ -252,7 +254,7 @@ where
 impl<'ch, M, T, K, const N: usize> Future for ReceiveFuture<'ch, M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     type Output = T;
@@ -284,7 +286,7 @@ impl<'ch, T> Future for DynamicReceiveFuture<'ch, T> {
 pub struct SendFuture<'ch, M, T, K, const N: usize>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     channel: &'ch PriorityChannel<M, T, K, N>,
@@ -294,7 +296,7 @@ where
 impl<'ch, M, T, K, const N: usize> Future for SendFuture<'ch, M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     type Output = ();
@@ -316,7 +318,7 @@ where
 impl<'ch, M, T, K, const N: usize> Unpin for SendFuture<'ch, M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
 }
@@ -347,34 +349,6 @@ impl<'ch, T> Future for DynamicSendFuture<'ch, T> {
 
 impl<'ch, T> Unpin for DynamicSendFuture<'ch, T> {}
 
-trait DynamicChannel<T> {
-    fn try_send_with_context(&self, message: T, cx: Option<&mut Context<'_>>) -> Result<(), TrySendError<T>>;
-
-    fn try_receive_with_context(&self, cx: Option<&mut Context<'_>>) -> Result<T, TryReceiveError>;
-
-    fn poll_ready_to_send(&self, cx: &mut Context<'_>) -> Poll<()>;
-    fn poll_ready_to_receive(&self, cx: &mut Context<'_>) -> Poll<()>;
-
-    fn poll_receive(&self, cx: &mut Context<'_>) -> Poll<T>;
-}
-
-/// Error returned by [`try_receive`](PriorityChannel::try_receive).
-#[derive(PartialEq, Eq, Clone, Copy, Debug)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-pub enum TryReceiveError {
-    /// A message could not be received because the channel is empty.
-    Empty,
-}
-
-/// Error returned by [`try_send`](PriorityChannel::try_send).
-#[derive(PartialEq, Eq, Clone, Copy, Debug)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
-pub enum TrySendError<T> {
-    /// The data could not be sent on the channel because the channel is
-    /// currently full and sending would require blocking.
-    Full(T),
-}
-
 struct ChannelState<T, K, const N: usize> {
     queue: BinaryHeap<T, K, N>,
     receiver_waker: WakerRegistration,
@@ -384,7 +358,7 @@ struct ChannelState<T, K, const N: usize> {
 impl<T, K, const N: usize> ChannelState<T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
 {
     const fn new() -> Self {
         ChannelState {
@@ -477,7 +451,7 @@ where
 pub struct PriorityChannel<M, T, K, const N: usize>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     inner: Mutex<M, RefCell<ChannelState<T, K, N>>>,
@@ -486,17 +460,18 @@ where
 impl<M, T, K, const N: usize> PriorityChannel<M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     /// Establish a new bounded channel. For example, to create one with a NoopMutex:
     ///
     /// ```
-    /// use embassy_sync::channel::PriorityChannel;
+    /// # use heapless::binary_heap::Max;
+    /// use embassy_sync::priority_channel::PriorityChannel;
     /// use embassy_sync::blocking_mutex::raw::NoopRawMutex;
     ///
     /// // Declare a bounded channel of 3 u32s.
-    /// let mut channel = PriorityChannel::<NoopRawMutex, u32, 3>::new();
+    /// let mut channel = PriorityChannel::<NoopRawMutex, u32, Max, 3>::new();
     /// ```
     pub const fn new() -> Self {
         Self {
@@ -588,7 +563,7 @@ where
 impl<M, T, K, const N: usize> DynamicChannel<T> for PriorityChannel<M, T, K, N>
 where
     T: Ord,
-    K: heapless::binary_heap::Kind,
+    K: Kind,
     M: RawMutex,
 {
     fn try_send_with_context(&self, m: T, cx: Option<&mut Context<'_>>) -> Result<(), TrySendError<T>> {
@@ -619,25 +594,30 @@ mod tests {
     use futures_executor::ThreadPool;
     use futures_timer::Delay;
     use futures_util::task::SpawnExt;
+    use heapless::binary_heap::{Kind, Max};
     use static_cell::StaticCell;
 
     use super::*;
     use crate::blocking_mutex::raw::{CriticalSectionRawMutex, NoopRawMutex};
 
-    fn capacity<T, const N: usize>(c: &ChannelState<T, N>) -> usize {
+    fn capacity<T, K, const N: usize>(c: &ChannelState<T, K, N>) -> usize
+    where
+        T: Ord,
+        K: Kind,
+    {
         c.queue.capacity() - c.queue.len()
     }
 
     #[test]
     fn sending_once() {
-        let mut c = ChannelState::<u32, 3>::new();
+        let mut c = ChannelState::<u32, Max, 3>::new();
         assert!(c.try_send(1).is_ok());
         assert_eq!(capacity(&c), 2);
     }
 
     #[test]
     fn sending_when_full() {
-        let mut c = ChannelState::<u32, 3>::new();
+        let mut c = ChannelState::<u32, Max, 3>::new();
         let _ = c.try_send(1);
         let _ = c.try_send(1);
         let _ = c.try_send(1);
@@ -650,7 +630,7 @@ mod tests {
 
     #[test]
     fn receiving_once_with_one_send() {
-        let mut c = ChannelState::<u32, 3>::new();
+        let mut c = ChannelState::<u32, Max, 3>::new();
         assert!(c.try_send(1).is_ok());
         assert_eq!(c.try_receive().unwrap(), 1);
         assert_eq!(capacity(&c), 3);
@@ -658,7 +638,7 @@ mod tests {
 
     #[test]
     fn receiving_when_empty() {
-        let mut c = ChannelState::<u32, 3>::new();
+        let mut c = ChannelState::<u32, Max, 3>::new();
         match c.try_receive() {
             Err(TryReceiveError::Empty) => assert!(true),
             _ => assert!(false),
@@ -668,14 +648,14 @@ mod tests {
 
     #[test]
     fn simple_send_and_receive() {
-        let c = PriorityChannel::<NoopRawMutex, u32, 3>::new();
+        let c = PriorityChannel::<NoopRawMutex, u32, Max, 3>::new();
         assert!(c.try_send(1).is_ok());
         assert_eq!(c.try_receive().unwrap(), 1);
     }
 
     #[test]
     fn cloning() {
-        let c = PriorityChannel::<NoopRawMutex, u32, 3>::new();
+        let c = PriorityChannel::<NoopRawMutex, u32, Max, 3>::new();
         let r1 = c.receiver();
         let s1 = c.sender();
 
@@ -685,7 +665,7 @@ mod tests {
 
     #[test]
     fn dynamic_dispatch() {
-        let c = PriorityChannel::<NoopRawMutex, u32, 3>::new();
+        let c = PriorityChannel::<NoopRawMutex, u32, Max, 3>::new();
         let s: DynamicSender<'_, u32> = c.sender().into();
         let r: DynamicReceiver<'_, u32> = c.receiver().into();
 
@@ -697,7 +677,7 @@ mod tests {
     async fn receiver_receives_given_try_send_async() {
         let executor = ThreadPool::new().unwrap();
 
-        static CHANNEL: StaticCell<PriorityChannel<CriticalSectionRawMutex, u32, 3>> = StaticCell::new();
+        static CHANNEL: StaticCell<PriorityChannel<CriticalSectionRawMutex, u32, Max, 3>> = StaticCell::new();
         let c = &*CHANNEL.init(PriorityChannel::new());
         let c2 = c;
         assert!(executor
@@ -710,7 +690,7 @@ mod tests {
 
     #[futures_test::test]
     async fn sender_send_completes_if_capacity() {
-        let c = PriorityChannel::<CriticalSectionRawMutex, u32, 1>::new();
+        let c = PriorityChannel::<CriticalSectionRawMutex, u32, Max, 1>::new();
         c.send(1).await;
         assert_eq!(c.receive().await, 1);
     }
@@ -719,7 +699,7 @@ mod tests {
     async fn senders_sends_wait_until_capacity() {
         let executor = ThreadPool::new().unwrap();
 
-        static CHANNEL: StaticCell<PriorityChannel<CriticalSectionRawMutex, u32, 1>> = StaticCell::new();
+        static CHANNEL: StaticCell<PriorityChannel<CriticalSectionRawMutex, u32, Max, 1>> = StaticCell::new();
         let c = &*CHANNEL.init(PriorityChannel::new());
         assert!(c.try_send(1).is_ok());