Remove the Pender enum

embassy-executor/src/arch/cortex_m.rs

@@ -1,28 +1,84 @@
 #[cfg(feature = "executor-thread")]
 pub use thread::*;
 
+use crate::raw::PenderContext;
+
+#[cfg(feature = "executor-interrupt")]
+
+/// # Safety
+///
+/// `irq` must be a valid interrupt request number
+unsafe fn nvic_pend(irq: u16) {
+    use cortex_m::interrupt::InterruptNumber;
+
+    #[derive(Clone, Copy)]
+    struct Irq(u16);
+    unsafe impl InterruptNumber for Irq {
+        fn number(self) -> u16 {
+            self.0
+        }
+    }
+
+    let irq = Irq(irq);
+
+    // STIR is faster, but is only available in v7 and higher.
+    #[cfg(not(armv6m))]
+    {
+        let mut nvic: cortex_m::peripheral::NVIC = unsafe { core::mem::transmute(()) };
+        nvic.request(irq);
+    }
+
+    #[cfg(armv6m)]
+    cortex_m::peripheral::NVIC::pend(irq);
+}
+
+#[cfg(all(feature = "executor-thread", feature = "executor-interrupt"))]
+#[export_name = "__pender"]
+fn __pender(context: PenderContext) {
+    unsafe {
+        // Safety: `context` is either `usize::MAX` created by `Executor::run`, or a valid interrupt
+        // request number given to `InterruptExecutor::start`.
+        if context as usize == usize::MAX {
+            core::arch::asm!("sev")
+        } else {
+            nvic_pend(context as u16)
+        }
+    }
+}
+
+#[cfg(all(feature = "executor-thread", not(feature = "executor-interrupt")))]
+#[export_name = "__pender"]
+fn __pender(_context: PenderContext) {
+    unsafe { core::arch::asm!("sev") }
+}
+
+#[cfg(all(not(feature = "executor-thread"), feature = "executor-interrupt"))]
+#[export_name = "__pender"]
+fn __pender(context: PenderContext) {
+    unsafe {
+        // Safety: `context` is the same value we passed to `InterruptExecutor::start`, which must
+        // be a valid interrupt request number.
+        nvic_pend(context as u16)
+    }
+}
+
 #[cfg(feature = "executor-thread")]
 mod thread {
 
     #[cfg(feature = "nightly")]
     pub use embassy_macros::main_cortex_m as main;
 
-    use crate::raw::OpaqueThreadContext;
+    use crate::raw::PenderContext;
     use crate::thread::ThreadContext;
 
-    #[export_name = "__thread_mode_pender"]
-    fn __thread_mode_pender(_context: OpaqueThreadContext) {
-        unsafe { core::arch::asm!("sev") }
-    }
-
     /// TODO
     // Name pending
     #[derive(Default)] // Default enables Executor::new
     pub struct Context;
 
     impl ThreadContext for Context {
-        fn context(&self) -> OpaqueThreadContext {
-            OpaqueThreadContext(0)
+        fn context(&self) -> PenderContext {
+            usize::MAX
         }
 
         fn wait(&mut self) {
@@ -35,7 +91,6 @@ mod thread {
     pub type Executor = crate::thread::ThreadModeExecutor<Context>;
 }
 
-// None of this has to be public, I guess?
 #[cfg(feature = "executor-interrupt")]
 pub use interrupt::*;
 #[cfg(feature = "executor-interrupt")]
@@ -44,23 +99,14 @@ mod interrupt {
     use cortex_m::peripheral::NVIC;
 
     use crate::interrupt::InterruptContext;
-    use crate::raw::OpaqueInterruptContext;
-
-    #[derive(Clone, Copy)]
-    struct CortexMInterruptContext(u16);
-
-    unsafe impl cortex_m::interrupt::InterruptNumber for CortexMInterruptContext {
-        fn number(self) -> u16 {
-            self.0
-        }
-    }
+    use crate::raw::PenderContext;
 
     impl<T> InterruptContext for T
     where
         T: InterruptNumber,
     {
-        fn context(&self) -> OpaqueInterruptContext {
-            OpaqueInterruptContext(self.number() as usize)
+        fn context(&self) -> PenderContext {
+            self.number() as usize
         }
 
         fn enable(&self) {
@@ -68,21 +114,6 @@ mod interrupt {
         }
     }
 
-    #[export_name = "__interrupt_mode_pender"]
-    fn __interrupt_mode_pender(interrupt: OpaqueInterruptContext) {
-        let interrupt = CortexMInterruptContext(unsafe { core::mem::transmute::<_, usize>(interrupt) as u16 });
-
-        // STIR is faster, but is only available in v7 and higher.
-        #[cfg(not(armv6m))]
-        {
-            let mut nvic: NVIC = unsafe { core::mem::transmute(()) };
-            nvic.request(interrupt);
-        }
-
-        #[cfg(armv6m)]
-        NVIC::pend(interrupt);
-    }
-
     /// TODO
     // Type alias for backwards compatibility
     pub type InterruptExecutor = crate::interrupt::InterruptModeExecutor;

embassy-executor/src/arch/riscv32.rs

@@ -10,14 +10,14 @@ mod thread {
     #[cfg(feature = "nightly")]
     pub use embassy_macros::main_riscv as main;
 
-    use crate::raw::OpaqueThreadContext;
+    use crate::raw::PenderContext;
     use crate::thread::ThreadContext;
 
     /// global atomic used to keep track of whether there is work to do since sev() is not available on RISCV
     static SIGNAL_WORK_THREAD_MODE: AtomicBool = AtomicBool::new(false);
 
-    #[export_name = "__thread_mode_pender"]
-    fn __thread_mode_pender(_context: OpaqueThreadContext) {
+    #[export_name = "__pender"]
+    fn __thread_mode_pender(_context: PenderContext) {
         SIGNAL_WORK_THREAD_MODE.store(true, Ordering::SeqCst);
     }
 
@@ -27,8 +27,8 @@ mod thread {
     pub struct Context;
 
     impl ThreadContext for Context {
-        fn context(&self) -> OpaqueThreadContext {
-            OpaqueThreadContext(0)
+        fn context(&self) -> PenderContext {
+            0
         }
 
         fn wait(&mut self) {

embassy-executor/src/arch/std.rs

@@ -10,7 +10,7 @@ mod thread {
     #[cfg(feature = "nightly")]
     pub use embassy_macros::main_std as main;
 
-    use crate::raw::OpaqueThreadContext;
+    use crate::raw::PenderContext;
     use crate::thread::ThreadContext;
 
     /// TODO
@@ -28,8 +28,8 @@ mod thread {
     }
 
     impl ThreadContext for Context {
-        fn context(&self) -> OpaqueThreadContext {
-            OpaqueThreadContext(self.signaler as *const _ as usize)
+        fn context(&self) -> PenderContext {
+            self.signaler as *const _ as usize
         }
 
         fn wait(&mut self) {
@@ -37,8 +37,8 @@ mod thread {
         }
     }
 
-    #[export_name = "__thread_mode_pender"]
-    fn __thread_mode_pender(context: OpaqueThreadContext) {
+    #[export_name = "__pender"]
+    fn __pender(context: PenderContext) {
         let signaler: &'static Signaler = unsafe { std::mem::transmute(context) };
         signaler.signal()
     }

embassy-executor/src/arch/wasm.rs

@@ -14,11 +14,11 @@ mod thread {
     use wasm_bindgen::prelude::*;
 
     use crate::raw::util::UninitCell;
-    use crate::raw::{OpaqueThreadContext, Pender};
+    use crate::raw::PenderContext;
     use crate::{raw, Spawner};
 
     #[export_name = "__thread_mode_pender"]
-    fn __thread_mode_pender(context: OpaqueThreadContext) {
+    fn __thread_mode_pender(context: PenderContext) {
         let signaler: &'static WasmContext = unsafe { std::mem::transmute(context) };
         let _ = signaler.promise.then(unsafe { signaler.closure.as_mut() });
     }
@@ -49,7 +49,7 @@ mod thread {
         pub fn new() -> Self {
             let ctx = &*Box::leak(Box::new(WasmContext::new()));
             Self {
-                inner: raw::Executor::new(Pender::Thread(OpaqueThreadContext(ctx as *const _ as usize))),
+                inner: raw::Executor::new(ctx as *const _ as usize),
                 ctx,
                 not_send: PhantomData,
             }

embassy-executor/src/arch/xtensa.rs

@@ -8,14 +8,14 @@ mod thread {
     use core::marker::PhantomData;
     use core::sync::atomic::{AtomicBool, Ordering};
 
-    use crate::raw::OpaqueThreadContext;
+    use crate::raw::PenderContext;
     use crate::thread::ThreadContext;
 
     /// global atomic used to keep track of whether there is work to do since sev() is not available on Xtensa
     static SIGNAL_WORK_THREAD_MODE: AtomicBool = AtomicBool::new(false);
 
     #[export_name = "__thread_mode_pender"]
-    fn __thread_mode_pender(_context: OpaqueThreadContext) {
+    fn __thread_mode_pender(_context: PenderContext) {
         SIGNAL_WORK_THREAD_MODE.store(true, Ordering::SeqCst);
     }
 
@@ -25,8 +25,8 @@ mod thread {
     pub struct Context;
 
     impl ThreadContext for Context {
-        fn context(&self) -> OpaqueThreadContext {
-            OpaqueThreadContext(0)
+        fn context(&self) -> PenderContext {
+            0
         }
 
         fn wait(&mut self) {

embassy-executor/src/interrupt.rs

@@ -5,7 +5,7 @@ use core::mem::MaybeUninit;
 
 use atomic_polyfill::{AtomicBool, Ordering};
 
-use crate::raw::{self, OpaqueInterruptContext, Pender};
+use crate::raw::{self, PenderContext};
 
 /// Architecture-specific interface for an interrupt-mode executor. This trait describes what data
 /// should be passed to the [`InterruptExecutor`]'s pender, and how to enable the interrupt that
@@ -15,7 +15,7 @@ pub trait InterruptContext {
     /// A pointer-sized piece of data that is passed to the pender function.
     ///
     /// Usually, the context contains the interrupt that should be used to wake the executor.
-    fn context(&self) -> OpaqueInterruptContext;
+    fn context(&self) -> PenderContext;
 
     /// Enabled the interrupt request.
     fn enable(&self);
@@ -104,7 +104,7 @@ impl InterruptModeExecutor {
         unsafe {
             (&mut *self.executor.get())
                 .as_mut_ptr()
-                .write(raw::Executor::new(Pender::Interrupt(irq.context())))
+                .write(raw::Executor::new(irq.context()))
         }
 
         let executor = unsafe { (&*self.executor.get()).assume_init_ref() };

embassy-executor/src/raw/mod.rs

@@ -292,54 +292,20 @@ impl<F: Future + 'static, const N: usize> TaskPool<F, N> {
 }
 
 /// Context given to the thread-mode executor's pender.
-#[repr(transparent)]
-#[derive(Clone, Copy)]
-pub struct OpaqueThreadContext(pub(crate) usize);
+pub type PenderContext = usize;
 
-/// Context given to the interrupt-mode executor's pender.
 #[derive(Clone, Copy)]
-#[repr(transparent)]
-pub struct OpaqueInterruptContext(pub(crate) usize);
-
-/// Platform/architecture-specific action executed when an executor has pending work.
-///
-/// When a task within an executor is woken, the `Pender` is called. This does a
-/// platform/architecture-specific action to signal there is pending work in the executor.
-/// When this happens, you must arrange for [`Executor::poll`] to be called.
-///
-/// You can think of it as a waker, but for the whole executor.
-#[derive(Clone, Copy)]
-pub enum Pender {
-    /// Pender for a thread-mode executor.
-    #[cfg(feature = "executor-thread")]
-    Thread(OpaqueThreadContext),
-
-    /// Pender for an interrupt-mode executor.
-    #[cfg(feature = "executor-interrupt")]
-    Interrupt(OpaqueInterruptContext),
-}
+pub(crate) struct Pender(PenderContext);
 
 unsafe impl Send for Pender {}
 unsafe impl Sync for Pender {}
 
 impl Pender {
     pub(crate) fn pend(self) {
-        match self {
-            #[cfg(feature = "executor-thread")]
-            Pender::Thread(core_id) => {
-                extern "Rust" {
-                    fn __thread_mode_pender(core_id: OpaqueThreadContext);
-                }
-                unsafe { __thread_mode_pender(core_id) };
-            }
-            #[cfg(feature = "executor-interrupt")]
-            Pender::Interrupt(interrupt) => {
-                extern "Rust" {
-                    fn __interrupt_mode_pender(interrupt: OpaqueInterruptContext);
-                }
-                unsafe { __interrupt_mode_pender(interrupt) };
-            }
+        extern "Rust" {
+            fn __pender(context: PenderContext);
         }
+        unsafe { __pender(self.0) };
     }
 }
 
@@ -499,9 +465,9 @@ impl Executor {
     /// When the executor has work to do, it will call the [`Pender`].
     ///
     /// See [`Executor`] docs for details on `Pender`.
-    pub fn new(pender: Pender) -> Self {
+    pub fn new(context: PenderContext) -> Self {
         Self {
-            inner: SyncExecutor::new(pender),
+            inner: SyncExecutor::new(Pender(context)),
             _not_sync: PhantomData,
         }
     }

embassy-executor/src/thread.rs

@@ -2,8 +2,8 @@
 
 use core::marker::PhantomData;
 
-use crate::raw::{OpaqueThreadContext, Pender};
-use crate::{raw, Spawner};
+use crate::raw::{self, PenderContext};
+use crate::Spawner;
 
 /// Architecture-specific interface for a thread-mode executor. This trait describes what the
 /// executor should do when idle, and what data should be passed to its pender.
@@ -13,7 +13,7 @@ pub trait ThreadContext: Sized {
     ///
     /// For example, on multi-core systems, this can be used to store the ID of the core that
     /// should be woken up.
-    fn context(&self) -> OpaqueThreadContext;
+    fn context(&self) -> PenderContext;
 
     /// Waits for the executor to be waken.
     ///
@@ -50,7 +50,7 @@ impl<C: ThreadContext> ThreadModeExecutor<C> {
     /// Create a new Executor using the given thread context.
     pub fn with_context(context: C) -> Self {
         Self {
-            inner: raw::Executor::new(Pender::Thread(context.context())),
+            inner: raw::Executor::new(context.context()),
             context,
             not_send: PhantomData,
         }