Merge branch 'embassy-rs:main' into stm32_adc_v3_hw_oversampling_support

17 files changed, 127 insertions, 18 deletions

diff --git a/embassy-sync/Cargo.toml b/embassy-sync/Cargo.toml
index 99962f9f6..9e5c39f5e 100644
--- a/embassy-sync/Cargo.toml
+++ b/embassy-sync/Cargo.toml
@@ -28,7 +28,7 @@ defmt = { version = "1.0.1", optional = true }
 log = { version = "0.4.14", optional = true }
 
 futures-sink = { version = "0.3", default-features = false, features = [] }
-futures-util = { version = "0.3.17", default-features = false }
+futures-core = { version = "0.3.31", default-features = false }
 critical-section = "1.1"
 heapless = "0.8"
 cfg-if = "1.0.0"
@@ -43,3 +43,4 @@ futures-util = { version = "0.3.17", features = [ "channel", "sink" ] }
 # Enable critical-section implementation for std, for tests
 critical-section = { version = "1.1", features = ["std"] }
 static_cell = { version = "2" }
+trybuild = "1.0.105"
diff --git a/embassy-sync/src/channel.rs b/embassy-sync/src/channel.rs
index 856551417..a0e39fcb5 100644
--- a/embassy-sync/src/channel.rs
+++ b/embassy-sync/src/channel.rs
@@ -17,6 +17,31 @@
 //! messages that it can store, and if this limit is reached, trying to send
 //! another message will result in an error being returned.
 //!
+//! # Example: Message passing between task and interrupt handler
+//!
+//! ```rust
+//! use embassy_sync::channel::Channel;
+//! use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
+//!
+//! static SHARED_CHANNEL: Channel<CriticalSectionRawMutex, u32, 8> = Channel::new();
+//!
+//! fn my_interrupt_handler() {
+//!     // Do some work..
+//!     // ...
+//!     if let Err(e) = SHARED_CHANNEL.sender().try_send(42) {
+//!         // Channel is full..
+//!     }
+//! }
+//!
+//! async fn my_async_task() {
+//!     // ...
+//!     let receiver = SHARED_CHANNEL.receiver();
+//!     loop {
+//!         let data_from_interrupt = receiver.receive().await;
+//!         // Do something with the data.
+//!     }
+//! }
+//! ```
 
 use core::cell::RefCell;
 use core::future::Future;
@@ -443,7 +468,7 @@ where
     }
 }
 
-impl<'ch, M, T, const N: usize> futures_util::Stream for Receiver<'ch, M, T, N>
+impl<'ch, M, T, const N: usize> futures_core::Stream for Receiver<'ch, M, T, N>
 where
     M: RawMutex,
 {
@@ -962,7 +987,7 @@ where
     }
 }
 
-impl<M, T, const N: usize> futures_util::Stream for Channel<M, T, N>
+impl<M, T, const N: usize> futures_core::Stream for Channel<M, T, N>
 where
     M: RawMutex,
 {
diff --git a/embassy-sync/src/lazy_lock.rs b/embassy-sync/src/lazy_lock.rs
index 18e3c2019..f1bd88b61 100644
--- a/embassy-sync/src/lazy_lock.rs
+++ b/embassy-sync/src/lazy_lock.rs
@@ -31,7 +31,12 @@ union Data<T, F> {
     f: ManuallyDrop<F>,
 }
 
-unsafe impl<T, F> Sync for LazyLock<T, F> {}
+unsafe impl<T, F> Sync for LazyLock<T, F>
+where
+    T: Sync,
+    F: Sync,
+{
+}
 
 impl<T, F: FnOnce() -> T> LazyLock<T, F> {
     /// Create a new uninitialized `StaticLock`.
diff --git a/embassy-sync/src/mutex.rs b/embassy-sync/src/mutex.rs
index 7528a9f68..8496f34bf 100644
--- a/embassy-sync/src/mutex.rs
+++ b/embassy-sync/src/mutex.rs
@@ -23,7 +23,7 @@ struct State {
 
 /// Async mutex.
 ///
-/// The mutex is generic over a blocking [`RawMutex`](crate::blocking_mutex::raw::RawMutex).
+/// The mutex is generic over a blocking [`RawMutex`].
 /// The raw mutex is used to guard access to the internal "is locked" flag. It
 /// is held for very short periods only, while locking and unlocking. It is *not* held
 /// for the entire time the async Mutex is locked.
diff --git a/embassy-sync/src/once_lock.rs b/embassy-sync/src/once_lock.rs
index cd05b986d..1e848685a 100644
--- a/embassy-sync/src/once_lock.rs
+++ b/embassy-sync/src/once_lock.rs
@@ -42,7 +42,7 @@ pub struct OnceLock<T> {
     data: Cell<MaybeUninit<T>>,
 }
 
-unsafe impl<T> Sync for OnceLock<T> {}
+unsafe impl<T> Sync for OnceLock<T> where T: Sync {}
 
 impl<T> OnceLock<T> {
     /// Create a new uninitialized `OnceLock`.
diff --git a/embassy-sync/src/pipe.rs b/embassy-sync/src/pipe.rs
index 2598652d2..df3b28b45 100644
--- a/embassy-sync/src/pipe.rs
+++ b/embassy-sync/src/pipe.rs
@@ -152,7 +152,7 @@ where
 
 impl<'p, M, const N: usize> Unpin for ReadFuture<'p, M, N> where M: RawMutex {}
 
-/// Future returned by [`Pipe::fill_buf`] and  [`Reader::fill_buf`].
+/// Future returned by [`Reader::fill_buf`].
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct FillBufFuture<'p, M, const N: usize>
 where
@@ -587,7 +587,7 @@ where
     }
 }
 
-/// Write-only access to a [`DynamicPipe`].
+/// Write-only access to the dynamic pipe.
 pub struct DynamicWriter<'p> {
     pipe: &'p dyn DynamicPipe,
 }
@@ -657,7 +657,7 @@ where
     }
 }
 
-/// Read-only access to a [`DynamicPipe`].
+/// Read-only access to a dynamic pipe.
 pub struct DynamicReader<'p> {
     pipe: &'p dyn DynamicPipe,
 }
@@ -742,7 +742,7 @@ where
     }
 }
 
-/// Future returned by [`DynamicPipe::fill_buf`] and  [`DynamicReader::fill_buf`].
+/// Future returned by [`DynamicReader::fill_buf`].
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct DynamicFillBufFuture<'p> {
     pipe: Option<&'p dyn DynamicPipe>,
diff --git a/embassy-sync/src/priority_channel.rs b/embassy-sync/src/priority_channel.rs
index 623c52993..715a20e86 100644
--- a/embassy-sync/src/priority_channel.rs
+++ b/embassy-sync/src/priority_channel.rs
@@ -1,7 +1,7 @@
 //! A queue for sending values between asynchronous tasks.
 //!
 //! Similar to a [`Channel`](crate::channel::Channel), however [`PriorityChannel`] sifts higher priority items to the front of the queue.
-//! Priority is determined by the `Ord` trait. Priority behavior is determined by the [`Kind`](heapless::binary_heap::Kind) parameter of the channel.
+//! Priority is determined by the `Ord` trait. Priority behavior is determined by the [`Kind`] parameter of the channel.
 
 use core::cell::RefCell;
 use core::future::Future;
@@ -473,7 +473,7 @@ where
 /// received from the channel.
 ///
 /// Sent data may be reordered based on their priority within the channel.
-/// For example, in a [`Max`](heapless::binary_heap::Max) [`PriorityChannel`]
+/// For example, in a [`Max`] [`PriorityChannel`]
 /// 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
diff --git a/embassy-sync/src/pubsub/mod.rs b/embassy-sync/src/pubsub/mod.rs
index 606efff0a..9206b9383 100644
--- a/embassy-sync/src/pubsub/mod.rs
+++ b/embassy-sync/src/pubsub/mod.rs
@@ -88,7 +88,7 @@ impl<M: RawMutex, T: Clone, const CAP: usize, const SUBS: usize, const PUBS: usi
     /// Create a new subscriber. It will only receive messages that are published after its creation.
     ///
     /// If there are no subscriber slots left, an error will be returned.
-    pub fn subscriber(&self) -> Result<Subscriber<M, T, CAP, SUBS, PUBS>, Error> {
+    pub fn subscriber(&self) -> Result<Subscriber<'_, M, T, CAP, SUBS, PUBS>, Error> {
         self.inner.lock(|inner| {
             let mut s = inner.borrow_mut();
 
@@ -120,7 +120,7 @@ impl<M: RawMutex, T: Clone, const CAP: usize, const SUBS: usize, const PUBS: usi
     /// Create a new publisher
     ///
     /// If there are no publisher slots left, an error will be returned.
-    pub fn publisher(&self) -> Result<Publisher<M, T, CAP, SUBS, PUBS>, Error> {
+    pub fn publisher(&self) -> Result<Publisher<'_, M, T, CAP, SUBS, PUBS>, Error> {
         self.inner.lock(|inner| {
             let mut s = inner.borrow_mut();
 
@@ -151,13 +151,13 @@ impl<M: RawMutex, T: Clone, const CAP: usize, const SUBS: usize, const PUBS: usi
 
     /// Create a new publisher that can only send immediate messages.
     /// This kind of publisher does not take up a publisher slot.
-    pub fn immediate_publisher(&self) -> ImmediatePublisher<M, T, CAP, SUBS, PUBS> {
+    pub fn immediate_publisher(&self) -> ImmediatePublisher<'_, M, T, CAP, SUBS, PUBS> {
         ImmediatePublisher(ImmediatePub::new(self))
     }
 
     /// Create a new publisher that can only send immediate messages.
     /// This kind of publisher does not take up a publisher slot.
-    pub fn dyn_immediate_publisher(&self) -> DynImmediatePublisher<T> {
+    pub fn dyn_immediate_publisher(&self) -> DynImmediatePublisher<'_, T> {
         DynImmediatePublisher(ImmediatePub::new(self))
     }
 
diff --git a/embassy-sync/src/pubsub/publisher.rs b/embassy-sync/src/pubsub/publisher.rs
index 7a1ab66de..52a52f926 100644
--- a/embassy-sync/src/pubsub/publisher.rs
+++ b/embassy-sync/src/pubsub/publisher.rs
@@ -75,7 +75,7 @@ impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> Pub<'a, PSB, T> {
         self.channel.is_full()
     }
 
-    /// Create a [`futures::Sink`] adapter for this publisher.
+    /// Create a [`futures_sink::Sink`] adapter for this publisher.
     #[inline]
     pub const fn sink(&self) -> PubSink<'a, '_, PSB, T> {
         PubSink { publ: self, fut: None }
diff --git a/embassy-sync/src/pubsub/subscriber.rs b/embassy-sync/src/pubsub/subscriber.rs
index 6ad660cb3..649382cf1 100644
--- a/embassy-sync/src/pubsub/subscriber.rs
+++ b/embassy-sync/src/pubsub/subscriber.rs
@@ -115,7 +115,7 @@ impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> Unpin for Sub<'a, PSB, T> {}
 
 /// Warning: The stream implementation ignores lag results and returns all messages.
 /// This might miss some messages without you knowing it.
-impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> futures_util::Stream for Sub<'a, PSB, T> {
+impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> futures_core::Stream for Sub<'a, PSB, T> {
     type Item = T;
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
diff --git a/embassy-sync/tests/ui.rs b/embassy-sync/tests/ui.rs
new file mode 100644
index 000000000..e8b1080d8
--- /dev/null
+++ b/embassy-sync/tests/ui.rs
@@ -0,0 +1,13 @@
+#[cfg(not(miri))]
+#[test]
+fn ui() {
+    let t = trybuild::TestCases::new();
+
+    // These test cases should fail to compile since OnceLock and LazyLock should not unconditionally implement sync
+    // for all types. These tests are regression tests against the following issues:
+    // * https://github.com/embassy-rs/embassy/issues/4307
+    // * https://github.com/embassy-rs/embassy/issues/3904
+    t.compile_fail("tests/ui/sync_impl/lazy_lock_function.rs");
+    t.compile_fail("tests/ui/sync_impl/lazy_lock_type.rs");
+    t.compile_fail("tests/ui/sync_impl/once_lock.rs");
+}
diff --git a/embassy-sync/tests/ui/sync_impl/lazy_lock_function.rs b/embassy-sync/tests/ui/sync_impl/lazy_lock_function.rs
new file mode 100644
index 000000000..35f5587c0
--- /dev/null
+++ b/embassy-sync/tests/ui/sync_impl/lazy_lock_function.rs
@@ -0,0 +1,11 @@
+use embassy_sync::lazy_lock::LazyLock;
+
+fn main() {
+    let x = 128u8;
+    let x_ptr: *const u8 = core::ptr::addr_of!(x);
+    let closure_capturing_non_sync_variable = || unsafe { core::ptr::read(x_ptr) };
+
+    check_sync(LazyLock::new(closure_capturing_non_sync_variable));
+}
+
+fn check_sync<T: Sync>(_lazy_lock: T) {}
diff --git a/embassy-sync/tests/ui/sync_impl/lazy_lock_function.stderr b/embassy-sync/tests/ui/sync_impl/lazy_lock_function.stderr
new file mode 100644
index 000000000..daf79ad28
--- /dev/null
+++ b/embassy-sync/tests/ui/sync_impl/lazy_lock_function.stderr
@@ -0,0 +1,24 @@
+error[E0277]: `*const u8` cannot be shared between threads safely
+  --> tests/ui/sync_impl/lazy_lock_function.rs:8:16
+   |
+6  |     let closure_capturing_non_sync_variable = || unsafe { core::ptr::read(x_ptr) };
+   |                                               -- within this `{closure@$DIR/tests/ui/sync_impl/lazy_lock_function.rs:6:47: 6:49}`
+7  |
+8  |     check_sync(LazyLock::new(closure_capturing_non_sync_variable));
+   |     ---------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `*const u8` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: within `{closure@$DIR/tests/ui/sync_impl/lazy_lock_function.rs:6:47: 6:49}`, the trait `Sync` is not implemented for `*const u8`
+   = note: required because it appears within the type `&*const u8`
+note: required because it's used within this closure
+  --> tests/ui/sync_impl/lazy_lock_function.rs:6:47
+   |
+6  |     let closure_capturing_non_sync_variable = || unsafe { core::ptr::read(x_ptr) };
+   |                                               ^^
+   = note: required for `embassy_sync::lazy_lock::LazyLock<u8, {closure@$DIR/tests/ui/sync_impl/lazy_lock_function.rs:6:47: 6:49}>` to implement `Sync`
+note: required by a bound in `check_sync`
+  --> tests/ui/sync_impl/lazy_lock_function.rs:11:18
+   |
+11 | fn check_sync<T: Sync>(_lazy_lock: T) {}
+   |                  ^^^^ required by this bound in `check_sync`
diff --git a/embassy-sync/tests/ui/sync_impl/lazy_lock_type.rs b/embassy-sync/tests/ui/sync_impl/lazy_lock_type.rs
new file mode 100644
index 000000000..4e1383143
--- /dev/null
+++ b/embassy-sync/tests/ui/sync_impl/lazy_lock_type.rs
@@ -0,0 +1,6 @@
+use embassy_sync::lazy_lock::LazyLock;
+
+// *mut u8 is not Sync, so LazyLock should not implement Sync for this type. This should fail to compile.
+static GLOBAL: LazyLock<*mut u8> = LazyLock::new(|| core::ptr::null_mut());
+
+fn main() {}
diff --git a/embassy-sync/tests/ui/sync_impl/lazy_lock_type.stderr b/embassy-sync/tests/ui/sync_impl/lazy_lock_type.stderr
new file mode 100644
index 000000000..1ccc54c7a
--- /dev/null
+++ b/embassy-sync/tests/ui/sync_impl/lazy_lock_type.stderr
@@ -0,0 +1,9 @@
+error[E0277]: `*mut u8` cannot be shared between threads safely
+ --> tests/ui/sync_impl/lazy_lock_type.rs:4:16
+  |
+4 | static GLOBAL: LazyLock<*mut u8> = LazyLock::new(|| core::ptr::null_mut());
+  |                ^^^^^^^^^^^^^^^^^ `*mut u8` cannot be shared between threads safely
+  |
+  = help: the trait `Sync` is not implemented for `*mut u8`
+  = note: required for `embassy_sync::lazy_lock::LazyLock<*mut u8>` to implement `Sync`
+  = note: shared static variables must have a type that implements `Sync`
diff --git a/embassy-sync/tests/ui/sync_impl/once_lock.rs b/embassy-sync/tests/ui/sync_impl/once_lock.rs
new file mode 100644
index 000000000..8f50d583b
--- /dev/null
+++ b/embassy-sync/tests/ui/sync_impl/once_lock.rs
@@ -0,0 +1,6 @@
+use embassy_sync::once_lock::OnceLock;
+
+// *mut u8 is not Sync, so OnceLock should not implement Sync for this type. This should fail to compile.
+static GLOBAL: OnceLock<*mut u8> = OnceLock::new();
+
+fn main() {}
diff --git a/embassy-sync/tests/ui/sync_impl/once_lock.stderr b/embassy-sync/tests/ui/sync_impl/once_lock.stderr
new file mode 100644
index 000000000..e2419f844
--- /dev/null
+++ b/embassy-sync/tests/ui/sync_impl/once_lock.stderr
@@ -0,0 +1,9 @@
+error[E0277]: `*mut u8` cannot be shared between threads safely
+ --> tests/ui/sync_impl/once_lock.rs:4:16
+  |
+4 | static GLOBAL: OnceLock<*mut u8> = OnceLock::new();
+  |                ^^^^^^^^^^^^^^^^^ `*mut u8` cannot be shared between threads safely
+  |
+  = help: the trait `Sync` is not implemented for `*mut u8`
+  = note: required for `embassy_sync::once_lock::OnceLock<*mut u8>` to implement `Sync`
+  = note: shared static variables must have a type that implements `Sync`