Added examples for async crates + fixed codegen for non-Copy arguments

rtic-channel/.gitignore

@@ -0,0 +1,2 @@
+Cargo.lock
+target/

rtic-channel/src/lib.rs

@@ -67,7 +67,7 @@ impl<T, const N: usize> Channel<T, N> {
     /// Split the queue into a `Sender`/`Receiver` pair.
     pub fn split<'a>(&'a mut self) -> (Sender<'a, T, N>, Receiver<'a, T, N>) {
         // Fill free queue
-        for idx in 0..(N - 1) as u8 {
+        for idx in 0..N as u8 {
             debug_assert!(!self.freeq.get_mut().is_full());
 
             // SAFETY: This safe as the loop goes from 0 to the capacity of the underlying queue.
@@ -114,11 +114,26 @@ macro_rules! make_channel {
 /// Error state for when the receiver has been dropped.
 pub struct NoReceiver<T>(pub T);
 
+impl<T> core::fmt::Debug for NoReceiver<T>
+where
+    T: core::fmt::Debug,
+{
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "NoReceiver({:?})", self.0)
+    }
+}
+
 /// A `Sender` can send to the channel and can be cloned.
 pub struct Sender<'a, T, const N: usize>(&'a Channel<T, N>);
 
 unsafe impl<'a, T, const N: usize> Send for Sender<'a, T, N> {}
 
+impl<'a, T, const N: usize> core::fmt::Debug for Sender<'a, T, N> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "Sender")
+    }
+}
+
 impl<'a, T, const N: usize> Sender<'a, T, N> {
     #[inline(always)]
     fn send_footer(&mut self, idx: u8, val: T) {
@@ -204,7 +219,7 @@ impl<'a, T, const N: usize> Sender<'a, T, N> {
                 // Return the index
                 Poll::Ready(Ok(idx))
             } else {
-                return Poll::Pending;
+                Poll::Pending
             }
         })
         .await;
@@ -267,16 +282,29 @@ impl<'a, T, const N: usize> Clone for Sender<'a, T, N> {
 /// A receiver of the channel. There can only be one receiver at any time.
 pub struct Receiver<'a, T, const N: usize>(&'a Channel<T, N>);
 
+unsafe impl<'a, T, const N: usize> Send for Receiver<'a, T, N> {}
+
+impl<'a, T, const N: usize> core::fmt::Debug for Receiver<'a, T, N> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "Receiver")
+    }
+}
+
 /// Error state for when all senders has been dropped.
 pub struct NoSender;
 
+impl core::fmt::Debug for NoSender {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "NoSender")
+    }
+}
+
 impl<'a, T, const N: usize> Receiver<'a, T, N> {
     /// Receives a value if there is one in the channel, non-blocking.
     /// Note; this does not check if the channel is closed.
     pub fn try_recv(&mut self) -> Option<T> {
         // Try to get a ready slot.
-        let ready_slot =
-            critical_section::with(|cs| self.0.access(cs).readyq.pop_front().map(|rs| rs));
+        let ready_slot = critical_section::with(|cs| self.0.access(cs).readyq.pop_front());
 
         if let Some(rs) = ready_slot {
             // Read the value from the slots, note; this memcpy is not under a critical section.

rtic-channel/src/wait_queue.rs

@@ -1,6 +1,5 @@
 //! ...
 
-use core::cell::UnsafeCell;
 use core::marker::PhantomPinned;
 use core::ptr::null_mut;
 use core::sync::atomic::{AtomicPtr, Ordering};
@@ -9,27 +8,6 @@ use critical_section as cs;
 
 pub type WaitQueue = LinkedList<Waker>;
 
-struct MyLinkPtr<T>(UnsafeCell<*mut Link<T>>);
-
-impl<T> MyLinkPtr<T> {
-    #[inline(always)]
-    fn new(val: *mut Link<T>) -> Self {
-        Self(UnsafeCell::new(val))
-    }
-
-    /// SAFETY: Only use this in a critical section, and don't forget them barriers.
-    #[inline(always)]
-    unsafe fn load_relaxed(&self) -> *mut Link<T> {
-        unsafe { *self.0.get() }
-    }
-
-    /// SAFETY: Only use this in a critical section, and don't forget them barriers.
-    #[inline(always)]
-    unsafe fn store_relaxed(&self, val: *mut Link<T>) {
-        unsafe { self.0.get().write(val) }
-    }
-}
-
 /// A FIFO linked list for a wait queue.
 pub struct LinkedList<T> {
     head: AtomicPtr<Link<T>>, // UnsafeCell<*mut Link<T>>

rtic-monotonics/Cargo.toml

@@ -10,3 +10,4 @@ cortex-m = { version = "0.7.6" }
 embedded-hal-async = "0.2.0-alpha.0"
 fugit = { version = "0.3.6", features = ["defmt"] }
 rtic-time = { version = "1.0.0", path = "../rtic-time" }
+atomic-polyfill = "1"

rtic-monotonics/src/systick_monotonic.rs

@@ -2,13 +2,11 @@
 
 use super::Monotonic;
 pub use super::{TimeoutError, TimerQueue};
-use core::{
-    ops::Deref,
-    sync::atomic::{AtomicU32, Ordering},
-};
+use atomic_polyfill::{AtomicU32, Ordering};
+use core::ops::Deref;
 use cortex_m::peripheral::SYST;
 use embedded_hal_async::delay::DelayUs;
-use fugit::ExtU32;
+pub use fugit::ExtU32;
 
 const TIMER_HZ: u32 = 1_000;
 

rtic/Cargo.toml

@@ -38,6 +38,9 @@ version_check = "0.9"
 lm3s6965 = "0.1.3"
 cortex-m-semihosting = "0.5.0"
 systick-monotonic = "1.0.0"
+rtic-time = { path = "../rtic-time" }
+rtic-channel = { path = "../rtic-channel" }
+rtic-monotonics = { path = "../rtic-monotonics" }
 
 [dev-dependencies.panic-semihosting]
 features = ["exit"]

rtic/ci/expected/async-channel.run

@@ -0,0 +1,6 @@
+Sender 1 sending: 1
+Sender 2 sending: 2
+Sender 3 sending: 3
+Receiver got: 1
+Receiver got: 2
+Receiver got: 5

rtic/ci/expected/message_passing.run

@@ -1,3 +1 @@
 foo 1, 1
-foo 1, 2
-foo 2, 3

rtic/examples/async-channel.rs

@@ -0,0 +1,61 @@
+//! examples/async-channel.rs
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+#![feature(type_alias_impl_trait)]
+
+use panic_semihosting as _;
+
+#[rtic::app(device = lm3s6965, dispatchers = [SSI0])]
+mod app {
+    use cortex_m_semihosting::{debug, hprintln};
+    use rtic_channel::*;
+
+    #[shared]
+    struct Shared {}
+
+    #[local]
+    struct Local {}
+
+    #[init]
+    fn init(_: init::Context) -> (Shared, Local) {
+        let (s, r) = make_channel!(u32, 5);
+
+        receiver::spawn(r).unwrap();
+        sender1::spawn(s.clone()).unwrap();
+        sender2::spawn(s.clone()).unwrap();
+        sender3::spawn(s).unwrap();
+
+        (Shared {}, Local {})
+    }
+
+    #[task]
+    async fn receiver(_c: receiver::Context, mut receiver: Receiver<'static, u32, 5>) {
+        while let Ok(val) = receiver.recv().await {
+            hprintln!("Receiver got: {}", val);
+            if val == 5 {
+                debug::exit(debug::EXIT_SUCCESS); // Exit QEMU simulator
+            }
+        }
+    }
+
+    #[task]
+    async fn sender1(_c: sender1::Context, mut sender: Sender<'static, u32, 5>) {
+        hprintln!("Sender 1 sending: 1");
+        sender.send(1).await.unwrap();
+    }
+
+    #[task]
+    async fn sender2(_c: sender2::Context, mut sender: Sender<'static, u32, 5>) {
+        hprintln!("Sender 2 sending: 2");
+        sender.send(2).await.unwrap();
+    }
+
+    #[task]
+    async fn sender3(_c: sender3::Context, mut sender: Sender<'static, u32, 5>) {
+        hprintln!("Sender 3 sending: 3");
+        sender.send(5).await.unwrap();
+    }
+}

rtic/examples/async-delay.rs

@@ -7,7 +7,9 @@ use panic_semihosting as _;
 #[rtic::app(device = lm3s6965, dispatchers = [SSI0, UART0], peripherals = true)]
 mod app {
     use cortex_m_semihosting::{debug, hprintln};
-    use systick_monotonic::*;
+    use rtic_monotonics::systick_monotonic::*;
+
+    rtic_monotonics::make_systick_timer_queue!(TIMER);
 
     #[shared]
     struct Shared {}
@@ -15,12 +17,12 @@ mod app {
     #[local]
     struct Local {}
 
-    #[monotonic(binds = SysTick, default = true)]
-    type MyMono = Systick<100>;
-
     #[init]
     fn init(cx: init::Context) -> (Shared, Local) {
-        hprintln!("init").unwrap();
+        hprintln!("init");
+
+        let systick = Systick::start(cx.core.SYST, 12_000_000);
+        TIMER.initialize(systick);
 
         foo::spawn().ok();
         bar::spawn().ok();
@@ -40,23 +42,23 @@ mod app {
 
     #[task]
     async fn foo(_cx: foo::Context) {
-        hprintln!("hello from foo").ok();
-        monotonics::delay(100.millis()).await;
-        hprintln!("bye from foo").ok();
+        hprintln!("hello from foo");
+        TIMER.delay(100.millis()).await;
+        hprintln!("bye from foo");
     }
 
     #[task]
     async fn bar(_cx: bar::Context) {
-        hprintln!("hello from bar").ok();
-        monotonics::delay(200.millis()).await;
-        hprintln!("bye from bar").ok();
+        hprintln!("hello from bar");
+        TIMER.delay(200.millis()).await;
+        hprintln!("bye from bar");
     }
 
     #[task]
     async fn baz(_cx: baz::Context) {
-        hprintln!("hello from baz").ok();
-        monotonics::delay(300.millis()).await;
-        hprintln!("bye from baz").ok();
+        hprintln!("hello from baz");
+        TIMER.delay(300.millis()).await;
+        hprintln!("bye from baz");
 
         debug::exit(debug::EXIT_SUCCESS);
     }

rtic/examples/message_passing.rs

@@ -4,6 +4,7 @@
 #![deny(warnings)]
 #![no_main]
 #![no_std]
+#![feature(type_alias_impl_trait)]
 
 use panic_semihosting as _;
 
@@ -18,20 +19,16 @@ mod app {
     struct Local {}
 
     #[init]
-    fn init(_: init::Context) -> (Shared, Local, init::Monotonics) {
+    fn init(_: init::Context) -> (Shared, Local) {
         foo::spawn(1, 1).unwrap();
-        foo::spawn(1, 2).unwrap();
-        foo::spawn(2, 3).unwrap();
         assert!(foo::spawn(1, 4).is_err()); // The capacity of `foo` is reached
 
-        (Shared {}, Local {}, init::Monotonics())
+        (Shared {}, Local {})
     }
 
-    #[task(capacity = 3)]
-    fn foo(_c: foo::Context, x: i32, y: u32) {
-        hprintln!("foo {}, {}", x, y).unwrap();
-        if x == 2 {
+    #[task]
+    async fn foo(_c: foo::Context, x: i32, y: u32) {
+        hprintln!("foo {}, {}", x, y);
         debug::exit(debug::EXIT_SUCCESS); // Exit QEMU simulator
     }
-    }
 }

rtic/macros/src/codegen/module.rs

@@ -157,15 +157,18 @@ pub fn codegen(ctxt: Context, app: &App, analysis: &Analysis) -> TokenStream2 {
             #[allow(non_snake_case)]
             #[doc(hidden)]
             pub fn #internal_spawn_ident(#(#input_args,)*) -> Result<(), #input_ty> {
-
-                if #exec_name.spawn(|| #name(unsafe { #name::Context::new() } #(,#input_untupled)*) ) {
-
+                // SAFETY: If `try_allocate` suceeds one must call `spawn`, which we do.
+                unsafe {
+                    if #exec_name.try_allocate() {
+                        let f = #name(unsafe { #name::Context::new() } #(,#input_untupled)*);
+                        #exec_name.spawn(f);
                         #pend_interrupt
 
                         Ok(())
                     } else {
                         Err(#input_tupled)
                     }
+                }
 
             }
         ));

rtic/src/export/executor.rs

@@ -70,25 +70,23 @@ impl<F: Future> AsyncTaskExecutor<F> {
         self.pending.store(true, Ordering::Release);
     }
 
-    /// Spawn a future
+    /// Allocate the executor. To use with `spawn`.
     #[inline(always)]
-    pub fn spawn(&self, future: impl Fn() -> F) -> bool {
+    pub unsafe fn try_allocate(&self) -> bool {
         // Try to reserve the executor for a future.
-        if self
-            .running
+        self.running
             .compare_exchange(false, true, Ordering::AcqRel, Ordering::Relaxed)
             .is_ok()
-        {
+    }
+
+    /// Spawn a future
+    #[inline(always)]
+    pub unsafe fn spawn(&self, future: F) {
         // This unsafe is protected by `running` being false and the atomic setting it to true.
         unsafe {
-                self.task.get().write(MaybeUninit::new(future()));
+            self.task.get().write(MaybeUninit::new(future));
         }
         self.set_pending();
-
-            true
-        } else {
-            false
-        }
     }
 
     /// Poll the future in the executor.