Merge branch 'embassy-rs:main' into reset-at-after

10 files changed, 67 insertions, 50 deletions

diff --git a/embassy-sync/Cargo.toml b/embassy-sync/Cargo.toml
index 38b0e5d30..85673026c 100644
--- a/embassy-sync/Cargo.toml
+++ b/embassy-sync/Cargo.toml
@@ -4,6 +4,7 @@ version = "0.5.0"
 edition = "2021"
 description = "no-std, no-alloc synchronization primitives with async support"
 repository = "https://github.com/embassy-rs/embassy"
+documentation = "https://docs.embassy.dev/embassy-sync"
 readme = "README.md"
 license = "MIT OR Apache-2.0"
 categories = [
diff --git a/embassy-sync/README.md b/embassy-sync/README.md
index 55618f72d..c2e13799e 100644
--- a/embassy-sync/README.md
+++ b/embassy-sync/README.md
@@ -17,17 +17,3 @@ Synchronization primitives and data structures with async support:
 ## Interoperability
 
 Futures from this crate can run on any executor.
-
-## Minimum supported Rust version (MSRV)
-
-Embassy is guaranteed to compile on the latest stable Rust version at the time of release. It might compile with older versions but that may change in any new patch release.
-
-## License
-
-This work is licensed under either of
-
-- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or
-  <http://www.apache.org/licenses/LICENSE-2.0>)
-- MIT license ([LICENSE-MIT](LICENSE-MIT) or <http://opensource.org/licenses/MIT>)
-
-at your option.
diff --git a/embassy-sync/build.rs b/embassy-sync/build.rs
index 0a796b881..afd76dad1 100644
--- a/embassy-sync/build.rs
+++ b/embassy-sync/build.rs
@@ -1,21 +1,8 @@
 use std::env;
-use std::ffi::OsString;
-use std::process::Command;
 
 fn main() {
     println!("cargo:rerun-if-changed=build.rs");
 
-    let rustc = env::var_os("RUSTC").unwrap_or_else(|| OsString::from("rustc"));
-
-    let output = Command::new(rustc)
-        .arg("--version")
-        .output()
-        .expect("failed to run `rustc --version`");
-
-    if String::from_utf8_lossy(&output.stdout).contains("nightly") {
-        println!("cargo:rustc-cfg=nightly");
-    }
-
     let target = env::var("TARGET").unwrap();
 
     if target.starts_with("thumbv6m-") {
diff --git a/embassy-sync/src/channel.rs b/embassy-sync/src/channel.rs
index ff7129303..48f4dafd6 100644
--- a/embassy-sync/src/channel.rs
+++ b/embassy-sync/src/channel.rs
@@ -263,6 +263,12 @@ impl<'ch, T> Future for DynamicReceiveFuture<'ch, T> {
     }
 }
 
+impl<'ch, M: RawMutex, T, const N: usize> From<ReceiveFuture<'ch, M, T, N>> for DynamicReceiveFuture<'ch, T> {
+    fn from(value: ReceiveFuture<'ch, M, T, N>) -> Self {
+        Self { channel: value.channel }
+    }
+}
+
 /// Future returned by [`Channel::send`] and  [`Sender::send`].
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct SendFuture<'ch, M, T, const N: usize>
@@ -321,6 +327,15 @@ impl<'ch, T> Future for DynamicSendFuture<'ch, T> {
 
 impl<'ch, T> Unpin for DynamicSendFuture<'ch, T> {}
 
+impl<'ch, M: RawMutex, T, const N: usize> From<SendFuture<'ch, M, T, N>> for DynamicSendFuture<'ch, T> {
+    fn from(value: SendFuture<'ch, M, T, N>) -> Self {
+        Self {
+            channel: value.channel,
+            message: value.message,
+        }
+    }
+}
+
 pub(crate) trait DynamicChannel<T> {
     fn try_send_with_context(&self, message: T, cx: Option<&mut Context<'_>>) -> Result<(), TrySendError<T>>;
 
@@ -507,6 +522,16 @@ where
         Receiver { channel: self }
     }
 
+    /// Get a sender for this channel using dynamic dispatch.
+    pub fn dyn_sender(&self) -> DynamicSender<'_, T> {
+        DynamicSender { channel: self }
+    }
+
+    /// Get a receiver for this channel using dynamic dispatch.
+    pub fn dyn_receiver(&self) -> DynamicReceiver<'_, T> {
+        DynamicReceiver { channel: self }
+    }
+
     /// Send a value, waiting until there is capacity.
     ///
     /// Sending completes when the value has been pushed to the channel's queue.
@@ -648,7 +673,7 @@ mod tests {
     }
 
     #[test]
-    fn dynamic_dispatch() {
+    fn dynamic_dispatch_into() {
         let c = Channel::<NoopRawMutex, u32, 3>::new();
         let s: DynamicSender<'_, u32> = c.sender().into();
         let r: DynamicReceiver<'_, u32> = c.receiver().into();
@@ -657,6 +682,16 @@ mod tests {
         assert_eq!(r.try_receive().unwrap(), 1);
     }
 
+    #[test]
+    fn dynamic_dispatch_constructor() {
+        let c = Channel::<NoopRawMutex, u32, 3>::new();
+        let s = c.dyn_sender();
+        let r = c.dyn_receiver();
+
+        assert!(s.try_send(1).is_ok());
+        assert_eq!(r.try_receive().unwrap(), 1);
+    }
+
     #[futures_test::test]
     async fn receiver_receives_given_try_send_async() {
         let executor = ThreadPool::new().unwrap();
diff --git a/embassy-sync/src/fmt.rs b/embassy-sync/src/fmt.rs
index 78e583c1c..2ac42c557 100644
--- a/embassy-sync/src/fmt.rs
+++ b/embassy-sync/src/fmt.rs
@@ -1,5 +1,5 @@
 #![macro_use]
-#![allow(unused_macros)]
+#![allow(unused)]
 
 use core::fmt::{Debug, Display, LowerHex};
 
@@ -229,7 +229,6 @@ impl<T, E> Try for Result<T, E> {
     }
 }
 
-#[allow(unused)]
 pub(crate) struct Bytes<'a>(pub &'a [u8]);
 
 impl<'a> Debug for Bytes<'a> {
diff --git a/embassy-sync/src/lib.rs b/embassy-sync/src/lib.rs
index b0ccfde57..d88c76db5 100644
--- a/embassy-sync/src/lib.rs
+++ b/embassy-sync/src/lib.rs
@@ -1,6 +1,4 @@
 #![cfg_attr(not(any(feature = "std", feature = "wasm")), no_std)]
-#![cfg_attr(nightly, feature(async_fn_in_trait, impl_trait_projections))]
-#![cfg_attr(nightly, allow(stable_features, unknown_lints))]
 #![allow(async_fn_in_trait)]
 #![allow(clippy::new_without_default)]
 #![doc = include_str!("../README.md")]
diff --git a/embassy-sync/src/priority_channel.rs b/embassy-sync/src/priority_channel.rs
index bd75c0135..e77678c24 100644
--- a/embassy-sync/src/priority_channel.rs
+++ b/embassy-sync/src/priority_channel.rs
@@ -325,7 +325,7 @@ where
 ///
 /// Sent data may be reordered based on their priorty within the channel.
 /// For example, in a [`Max`](heapless::binary_heap::Max) [`PriorityChannel`]
-/// containing `u32`'s, data sent in the following order `[1, 2, 3]` will be recieved as `[3, 2, 1]`.
+/// containing `u32`'s, data sent in the following order `[1, 2, 3]` will be received as `[3, 2, 1]`.
 pub struct PriorityChannel<M, T, K, const N: usize>
 where
     T: Ord,
diff --git a/embassy-sync/src/ring_buffer.rs b/embassy-sync/src/ring_buffer.rs
index d95ffa7c9..81e60c42b 100644
--- a/embassy-sync/src/ring_buffer.rs
+++ b/embassy-sync/src/ring_buffer.rs
@@ -3,7 +3,7 @@ use core::ops::Range;
 pub struct RingBuffer<const N: usize> {
     start: usize,
     end: usize,
-    empty: bool,
+    full: bool,
 }
 
 impl<const N: usize> RingBuffer<N> {
@@ -11,13 +11,13 @@ impl<const N: usize> RingBuffer<N> {
         Self {
             start: 0,
             end: 0,
-            empty: true,
+            full: false,
         }
     }
 
     pub fn push_buf(&mut self) -> Range<usize> {
-        if self.start == self.end && !self.empty {
-            trace!("  ringbuf: push_buf empty");
+        if self.is_full() {
+            trace!("  ringbuf: push_buf full");
             return 0..0;
         }
 
@@ -38,11 +38,11 @@ impl<const N: usize> RingBuffer<N> {
         }
 
         self.end = self.wrap(self.end + n);
-        self.empty = false;
+        self.full = self.start == self.end;
     }
 
     pub fn pop_buf(&mut self) -> Range<usize> {
-        if self.empty {
+        if self.is_empty() {
             trace!("  ringbuf: pop_buf empty");
             return 0..0;
         }
@@ -64,20 +64,20 @@ impl<const N: usize> RingBuffer<N> {
         }
 
         self.start = self.wrap(self.start + n);
-        self.empty = self.start == self.end;
+        self.full = false;
     }
 
     pub fn is_full(&self) -> bool {
-        self.start == self.end && !self.empty
+        self.full
     }
 
     pub fn is_empty(&self) -> bool {
-        self.empty
+        self.start == self.end && !self.full
     }
 
     #[allow(unused)]
     pub fn len(&self) -> usize {
-        if self.empty {
+        if self.is_empty() {
             0
         } else if self.start < self.end {
             self.end - self.start
@@ -89,7 +89,7 @@ impl<const N: usize> RingBuffer<N> {
     pub fn clear(&mut self) {
         self.start = 0;
         self.end = 0;
-        self.empty = true;
+        self.full = false;
     }
 
     fn wrap(&self, n: usize) -> usize {
diff --git a/embassy-sync/src/signal.rs b/embassy-sync/src/signal.rs
index bea67d8be..520f1a896 100644
--- a/embassy-sync/src/signal.rs
+++ b/embassy-sync/src/signal.rs
@@ -111,7 +111,21 @@ where
         poll_fn(move |cx| self.poll_wait(cx))
     }
 
-    /// non-blocking method to check whether this signal has been signaled.
+    /// non-blocking method to try and take the signal value.
+    pub fn try_take(&self) -> Option<T> {
+        self.state.lock(|cell| {
+            let state = cell.replace(State::None);
+            match state {
+                State::Signaled(res) => Some(res),
+                state => {
+                    cell.set(state);
+                    None
+                }
+            }
+        })
+    }
+
+    /// non-blocking method to check whether this signal has been signaled. This does not clear the signal.  
     pub fn signaled(&self) -> bool {
         self.state.lock(|cell| {
             let state = cell.replace(State::None);
diff --git a/embassy-sync/src/zerocopy_channel.rs b/embassy-sync/src/zerocopy_channel.rs
index f704cbd5d..cfce9a571 100644
--- a/embassy-sync/src/zerocopy_channel.rs
+++ b/embassy-sync/src/zerocopy_channel.rs
@@ -1,10 +1,7 @@
 //! A zero-copy queue for sending values between asynchronous tasks.
 //!
-//! It can be used concurrently by multiple producers (senders) and multiple
-//! consumers (receivers), i.e. it is an  "MPMC channel".
-//!
-//! Receivers are competing for messages. So a message that is received by
-//! one receiver is not received by any other.
+//! It can be used concurrently by a producer (sender) and a
+//! consumer (receiver), i.e. it is an  "SPSC channel".
 //!
 //! This queue takes a Mutex type so that various
 //! targets can be attained. For example, a ThreadModeMutex can be used