update examples

examples/full-syntax.rs

@@ -1,6 +1,5 @@
 //! A showcase of the `app!` macro syntax
 #![deny(unsafe_code)]
-#![feature(const_fn)]
 #![feature(proc_macro)]
 #![no_std]
 

examples/nested.rs

@@ -3,7 +3,6 @@
 //! If you run this program you'll hit the breakpoints as indicated by the
 //! letters in the comments: A, then B, then C, etc.
 #![deny(unsafe_code)]
-#![feature(const_fn)]
 #![feature(proc_macro)]
 #![no_std]
 
@@ -59,13 +58,14 @@ fn idle() -> ! {
     }
 }
 
-fn exti0(t: &mut Threshold, r: EXTI0::Resources) {
+#[allow(non_snake_case)]
+fn exti0(
+    t: &mut Threshold,
+    EXTI0::Resources { mut LOW, mut HIGH }: EXTI0::Resources,
+) {
     // Because this task has a priority of 1 the preemption threshold `t` also
     // starts at 1
 
-    let mut low = r.LOW;
-    let mut high = r.HIGH;
-
     // B
     rtfm::bkpt();
 
@@ -73,7 +73,7 @@ fn exti0(t: &mut Threshold, r: EXTI0::Resources) {
     rtfm::set_pending(Interrupt::EXTI1); // ~> exti1
 
     // A claim creates a critical section
-    low.claim_mut(t, |_low, t| {
+    LOW.claim_mut(t, |_low, t| {
         // This claim increases the preemption threshold to 2
         //
         // 2 is just high enough to not race with task `exti1` for access to the
@@ -94,7 +94,7 @@ fn exti0(t: &mut Threshold, r: EXTI0::Resources) {
         rtfm::bkpt();
 
         // Claims can be nested
-        high.claim_mut(t, |_high, _| {
+        HIGH.claim_mut(t, |_high, _| {
             // This claim increases the preemption threshold to 3
 
             // Now `exti2` can't preempt this task

examples/one-task.rs

@@ -1,6 +1,5 @@
 //! An application with one task
 #![deny(unsafe_code)]
-#![feature(const_fn)]
 #![feature(proc_macro)]
 #![no_std]
 
@@ -34,17 +33,6 @@ app! {
             // Path to the task handler
             path: sys_tick,
 
-            // This is the priority of the task.
-            //
-            // 1 is the lowest priority a task can have, and the maximum
-            // priority is determined by the number of priority bits the device
-            // has. `stm32f103xx` has 4 priority bits so 16 is the maximum valid
-            // value.
-            //
-            // You can omit this field. If you do the priority is assumed to be
-            // 1.
-            priority: 1,
-
             // These are the resources this task has access to.
             //
             // A resource can be a peripheral like `GPIOC` or a static variable
@@ -54,7 +42,10 @@ app! {
     }
 }
 
-fn init(p: init::Peripherals, _r: init::Resources) {
+fn init(p: init::Peripherals, r: init::Resources) {
+    // `init` can modify all the `resources` declared in `app!`
+    r.ON;
+
     // power on GPIOC
     p.RCC.apb2enr.modify(|_, w| w.iopcen().enabled());
 
@@ -81,7 +72,7 @@ fn idle() -> ! {
 //
 // `_t` is the preemption threshold token. We won't use it in this program.
 //
-// `r` is the set of resources this task has access to. `TIMER0_A1::Resources`
+// `r` is the set of resources this task has access to. `SYS_TICK::Resources`
 // has one field per resource declared in `app!`.
 fn sys_tick(_t: &mut Threshold, r: SYS_TICK::Resources) {
     // toggle state

examples/preemption.rs

@@ -1,6 +1,5 @@
 //! Two tasks running at *different* priorities with access to the same resource
 #![deny(unsafe_code)]
-#![feature(const_fn)]
 #![feature(proc_macro)]
 #![no_std]
 
@@ -58,8 +57,11 @@ fn tim2(t: &mut Threshold, mut r: TIM2::Resources) {
     // As this task runs at lower priority it needs a critical section to
     // prevent `sys_tick` from preempting it while it modifies this resource
     // data. The critical section is required to prevent data races which can
-    // lead to undefined behavior
-    r.COUNTER.claim_mut(t, |counter, _t| { **counter += 1; });
+    // lead to undefined behavior.
+    r.COUNTER.claim_mut(t, |counter, _t| {
+        // `claim_mut` creates a critical section
+        **counter += 1;
+    });
 
     // ..
 }

examples/two-tasks.rs

@@ -1,7 +1,5 @@
 //! Two tasks running at the *same* priority with access to the same resource
-
 #![deny(unsafe_code)]
-#![feature(const_fn)]
 #![feature(proc_macro)]
 #![no_std]
 
@@ -31,8 +29,6 @@ app! {
     },
 }
 
-// When data resources are declared in the top `resources` field, `init` will
-// have full access to them
 fn init(_p: init::Peripherals, _r: init::Resources) {
     // ..
 }