Add embedded_dma feature

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Implemented `retain` for `IndexMap` and `IndexSet`.
 - Recover `StableDeref` trait for `pool::object::Object` and `pool::boxed::Box`.
 - Add polyfills for ESP32S2
+- Add `embedded_dma` feature to one can send `Vec`, `pool::object::Object` and `pool::boxed::Box` to DMA as read/write buffers [#362].
 
 ### Changed
 

Cargo.toml

@@ -24,6 +24,7 @@ __trybuild = []
 mpmc_large = []
 # This flag has no version guarantee, the `defmt` dependency can be updated in a patch release
 defmt-impl = ["defmt"]
+embedded-dma = ["dep:embedded-dma"]
 
 [target.thumbv6m-none-eabi.dependencies]
 atomic-polyfill = { version = "1.0.1", optional = true }
@@ -59,6 +60,10 @@ default-features = false
 version = "0.1"
 optional = true
 
+[dependencies.embedded-dma]
+version = "0.2"
+optional = true
+
 [dev-dependencies.ufmt]
 version = "0.1"
 

cfail/ui/not-send.stderr

@@ -1,5 +1,5 @@
 error[E0277]: `*const ()` cannot be sent between threads safely
-  --> $DIR/not-send.rs:19:15
+  --> ui/not-send.rs:19:15
    |
 19 |     is_send::<Consumer<NotSend, 4>>();
    |               ^^^^^^^^^^^^^^^^^^^^ `*const ()` cannot be sent between threads safely
@@ -8,7 +8,7 @@ error[E0277]: `*const ()` cannot be sent between threads safely
    = note: required because it appears within the type `PhantomData<*const ()>`
    = note: required for `Consumer<'_, PhantomData<*const ()>, 4>` to implement `Send`
 note: required by a bound in `is_send`
-  --> $DIR/not-send.rs:14:8
+  --> ui/not-send.rs:14:8
    |
 12 | fn is_send<T>()
    |    ------- required by a bound in this
@@ -17,7 +17,7 @@ note: required by a bound in `is_send`
    |        ^^^^ required by this bound in `is_send`
 
 error[E0277]: `*const ()` cannot be sent between threads safely
-  --> $DIR/not-send.rs:20:15
+  --> ui/not-send.rs:20:15
    |
 20 |     is_send::<Producer<NotSend, 4>>();
    |               ^^^^^^^^^^^^^^^^^^^^ `*const ()` cannot be sent between threads safely
@@ -26,7 +26,7 @@ error[E0277]: `*const ()` cannot be sent between threads safely
    = note: required because it appears within the type `PhantomData<*const ()>`
    = note: required for `Producer<'_, PhantomData<*const ()>, 4>` to implement `Send`
 note: required by a bound in `is_send`
-  --> $DIR/not-send.rs:14:8
+  --> ui/not-send.rs:14:8
    |
 12 | fn is_send<T>()
    |    ------- required by a bound in this
@@ -35,7 +35,7 @@ note: required by a bound in `is_send`
    |        ^^^^ required by this bound in `is_send`
 
 error[E0277]: `*const ()` cannot be sent between threads safely
-  --> $DIR/not-send.rs:21:15
+  --> ui/not-send.rs:21:15
    |
 21 |     is_send::<Queue<NotSend, 4>>();
    |               ^^^^^^^^^^^^^^^^^ `*const ()` cannot be sent between threads safely
@@ -48,7 +48,7 @@ error[E0277]: `*const ()` cannot be sent between threads safely
    = note: required because it appears within the type `[UnsafeCell<MaybeUninit<PhantomData<*const ()>>>; 4]`
    = note: required because it appears within the type `Queue<PhantomData<*const ()>, 4>`
 note: required by a bound in `is_send`
-  --> $DIR/not-send.rs:14:8
+  --> ui/not-send.rs:14:8
    |
 12 | fn is_send<T>()
    |    ------- required by a bound in this
@@ -57,7 +57,7 @@ note: required by a bound in `is_send`
    |        ^^^^ required by this bound in `is_send`
 
 error[E0277]: `*const ()` cannot be sent between threads safely
-  --> $DIR/not-send.rs:22:15
+  --> ui/not-send.rs:22:15
    |
 22 |     is_send::<Vec<NotSend, 4>>();
    |               ^^^^^^^^^^^^^^^ `*const ()` cannot be sent between threads safely
@@ -69,7 +69,7 @@ error[E0277]: `*const ()` cannot be sent between threads safely
    = note: required because it appears within the type `[MaybeUninit<PhantomData<*const ()>>; 4]`
    = note: required because it appears within the type `heapless::Vec<PhantomData<*const ()>, 4>`
 note: required by a bound in `is_send`
-  --> $DIR/not-send.rs:14:8
+  --> ui/not-send.rs:14:8
    |
 12 | fn is_send<T>()
    |    ------- required by a bound in this
@@ -78,7 +78,7 @@ note: required by a bound in `is_send`
    |        ^^^^ required by this bound in `is_send`
 
 error[E0277]: `*const ()` cannot be sent between threads safely
-  --> $DIR/not-send.rs:23:15
+  --> ui/not-send.rs:23:15
    |
 23 |     is_send::<HistoryBuffer<NotSend, 4>>();
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^ `*const ()` cannot be sent between threads safely
@@ -90,7 +90,7 @@ error[E0277]: `*const ()` cannot be sent between threads safely
    = note: required because it appears within the type `[MaybeUninit<PhantomData<*const ()>>; 4]`
    = note: required because it appears within the type `HistoryBuffer<PhantomData<*const ()>, 4>`
 note: required by a bound in `is_send`
-  --> $DIR/not-send.rs:14:8
+  --> ui/not-send.rs:14:8
    |
 12 | fn is_send<T>()
    |    ------- required by a bound in this

src/vec.rs

@@ -1181,6 +1181,32 @@ where
     }
 }
 
+#[cfg(feature = "embedded-dma")]
+unsafe impl<T, const N: usize> embedded_dma::ReadTarget for Vec<T, N>
+where
+    T: embedded_dma::ReadTarget,
+{
+    type Word = T::Word;
+
+    // Replace default implementation to return self.len() as buffer size
+    fn as_read_buffer(&self) -> (*const Self::Word, usize) {
+        (self.as_ptr() as *const T::Word, self.len)
+    }
+}
+
+#[cfg(feature = "embedded-dma")]
+unsafe impl<T, const N: usize> embedded_dma::WriteTarget for Vec<T, N>
+where
+    T: embedded_dma::WriteTarget,
+{
+    type Word = T::Word;
+
+    // Replace default implementation to return N as buffer size
+    fn as_write_buffer(&mut self) -> (*mut Self::Word, usize) {
+        (self.as_mut_ptr() as *mut T::Word, N)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::Vec;