From f88f233e39f1edef04a51b888a47b9e231fc228f Mon Sep 17 00:00:00 2001
From: Dario Nieuwenhuis <dirbaio@dirbaio.net>
Date: Fri, 25 Sep 2020 23:42:49 +0200
Subject: [PATCH] Remove executor model (it's not a nice enough abstraction).

---
 embassy/src/executor.rs       | 37 ++++++-----------------------------
 examples/src/bin/rtc_async.rs | 11 +++++++----
 2 files changed, 13 insertions(+), 35 deletions(-)

diff --git a/embassy/src/executor.rs b/embassy/src/executor.rs
index 2c7cc5786..d42a19b9a 100644
--- a/embassy/src/executor.rs
+++ b/embassy/src/executor.rs
@@ -6,33 +6,19 @@ use crate::time::Alarm;
 
 pub use se::{task, SpawnError, SpawnToken};
 
-pub trait Model {
-    fn signal();
-}
-
-pub struct WfeModel;
-
-impl Model for WfeModel {
-    fn signal() {
-        cortex_m::asm::sev()
-    }
-}
-
-pub struct Executor<M, A: Alarm> {
+pub struct Executor<A: Alarm> {
     inner: se::Executor,
     alarm: A,
     timer: time::TimerService,
-    _phantom: PhantomData<M>,
 }
 
-impl<M: Model, A: Alarm> Executor<M, A> {
-    pub fn new(alarm: A) -> Self {
-        alarm.set_callback(M::signal);
+impl<A: Alarm> Executor<A> {
+    pub fn new(alarm: A, signal_fn: fn()) -> Self {
+        alarm.set_callback(signal_fn);
         Self {
-            inner: se::Executor::new(M::signal),
+            inner: se::Executor::new(signal_fn),
             alarm,
             timer: time::TimerService::new(time::IntrusiveClock),
-            _phantom: PhantomData,
         }
     }
 
@@ -46,7 +32,7 @@ impl<M: Model, A: Alarm> Executor<M, A> {
     /// Runs the executor until the queue is empty.
     ///
     /// safety: can only be called from the executor thread
-    pub unsafe fn run_once(&'static self) {
+    pub unsafe fn run(&'static self) {
         time::with_timer_service(&self.timer, || {
             self.timer.check_expirations();
             self.inner.run();
@@ -60,14 +46,3 @@ impl<M: Model, A: Alarm> Executor<M, A> {
         })
     }
 }
-
-impl<A: Alarm> Executor<WfeModel, A> {
-    /// Runs the executor forever
-    /// safety: can only be called from the executor thread
-    pub unsafe fn run(&'static self) -> ! {
-        loop {
-            self.run_once();
-            cortex_m::asm::wfe()
-        }
-    }
-}
diff --git a/examples/src/bin/rtc_async.rs b/examples/src/bin/rtc_async.rs
index a4149ef1e..30b181a93 100644
--- a/examples/src/bin/rtc_async.rs
+++ b/examples/src/bin/rtc_async.rs
@@ -8,7 +8,7 @@ use example_common::*;
 
 use core::mem::MaybeUninit;
 use cortex_m_rt::entry;
-use embassy::executor::{task, Executor, WfeModel};
+use embassy::executor::{task, Executor};
 use embassy::time::{Clock, Duration, Timer};
 use embassy_nrf::pac;
 use embassy_nrf::rtc;
@@ -31,7 +31,7 @@ async fn run2() {
 }
 
 static mut RTC: MaybeUninit<rtc::RTC<pac::RTC1>> = MaybeUninit::uninit();
-static mut EXECUTOR: MaybeUninit<Executor<WfeModel, rtc::Alarm<pac::RTC1>>> = MaybeUninit::uninit();
+static mut EXECUTOR: MaybeUninit<Executor<rtc::Alarm<pac::RTC1>>> = MaybeUninit::uninit();
 
 #[entry]
 fn main() -> ! {
@@ -55,7 +55,7 @@ fn main() -> ! {
 
     let executor: &'static _ = unsafe {
         let ptr = EXECUTOR.as_mut_ptr();
-        ptr.write(Executor::new(rtc.alarm0()));
+        ptr.write(Executor::new(rtc.alarm0(), cortex_m::asm::sev));
         &*ptr
     };
 
@@ -63,6 +63,9 @@ fn main() -> ! {
         executor.spawn(run1()).dewrap();
         executor.spawn(run2()).dewrap();
 
-        executor.run()
+        loop {
+            executor.run();
+            cortex_m::asm::wfe();
+        }
     }
 }