Enhancements to the TimerService trait

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Breaking change: Upgraded to `embedded-io` 0.5 and `embedded-io-async` 0.5
 * Upgraded `strum` and `strum-macros` to 0.25
 * OTA: New method: `Ota::finish` that allows to postpone/avoid setting the updated partition as a boot one
+* TimerService: `TimerService::timer` now takes `&self` instead of `&mut self`
+* Breaking change: TimerService: scoped handler: the timer handler now only needs to live as long as the `TimerService::Timer` associated type. Therefore, `TimerService::Timer` is now lifetimed: `TimerService::Timer<'a>`
 * Breaking change: OTA: GAT `Ota::Update` now parametric over lifetime and no longer returned by `&mut` ref
 * Breaking change: OTA: `OtaUpdate::abort` and `OtaUpdate::complete` now take `self` instead of `&mut self`
 * Breaking change: MQTT: GAT `Connection::Message` now parametric over lifetime

src/timer.rs

@@ -68,28 +68,40 @@ where
 }
 
 pub trait TimerService: ErrorType {
-    type Timer: OnceTimer<Error = Self::Error> + PeriodicTimer<Error = Self::Error> + 'static;
+    type Timer<'a>: OnceTimer<Error = Self::Error> + PeriodicTimer<Error = Self::Error> + 'a;
 
-    fn timer(
-        &mut self,
-        callback: impl FnMut() + Send + 'static,
-    ) -> Result<Self::Timer, Self::Error>;
+    fn timer<'a>(&self, callback: impl FnMut() + Send + 'a)
+        -> Result<Self::Timer<'a>, Self::Error>;
 }
 
-impl<S> TimerService for &mut S
+impl<S> TimerService for &S
 where
     S: TimerService,
 {
-    type Timer = S::Timer;
+    type Timer<'a> = S::Timer<'a>;
 
-    fn timer(
-        &mut self,
-        callback: impl FnMut() + Send + 'static,
-    ) -> Result<Self::Timer, Self::Error> {
+    fn timer<'a>(
+        &self,
+        callback: impl FnMut() + Send + 'a,
+    ) -> Result<Self::Timer<'a>, Self::Error> {
         (*self).timer(callback)
     }
 }
 
+impl<S> TimerService for &mut S
+where
+    S: TimerService,
+{
+    type Timer<'a> = S::Timer<'a>;
+
+    fn timer<'a>(
+        &self,
+        callback: impl FnMut() + Send + 'a,
+    ) -> Result<Self::Timer<'a>, Self::Error> {
+        (**self).timer(callback)
+    }
+}
+
 #[cfg(feature = "nightly")]
 pub mod asynch {
     use core::time::Duration;
@@ -150,17 +162,28 @@ pub mod asynch {
             + Send
             + 'static;
 
-        fn timer(&mut self) -> Result<Self::Timer, Self::Error>;
+        fn timer(&self) -> Result<Self::Timer, Self::Error>;
     }
 
-    impl<T> TimerService for &mut T
+    impl<T> TimerService for &T
     where
         T: TimerService,
     {
         type Timer = T::Timer;
 
-        fn timer(&mut self) -> Result<Self::Timer, Self::Error> {
+        fn timer(&self) -> Result<Self::Timer, Self::Error> {
             (*self).timer()
         }
     }
+
+    impl<T> TimerService for &mut T
+    where
+        T: TimerService,
+    {
+        type Timer = T::Timer;
+
+        fn timer(&self) -> Result<Self::Timer, Self::Error> {
+            (**self).timer()
+        }
+    }
 }

src/utils/asyncify/timer.rs

@@ -140,9 +140,9 @@ where
 impl<T> AsyncTimerService<T>
 where
     T: crate::timer::TimerService,
-    T::Timer: Send,
+    for<'a> T::Timer<'a>: Send,
 {
-    pub fn timer(&mut self) -> Result<AsyncTimer<T::Timer>, T::Error> {
+    pub fn timer(&self) -> Result<AsyncTimer<T::Timer<'static>>, T::Error> {
         let signal = Arc::new(TimerSignal::new());
 
         let timer = {
@@ -226,11 +226,11 @@ mod async_traits_impl {
     impl<T> TimerService for AsyncTimerService<T>
     where
         T: crate::timer::TimerService,
-        T::Timer: Send,
+        for<'a> T::Timer<'a>: Send,
     {
-        type Timer = AsyncTimer<T::Timer>;
+        type Timer = AsyncTimer<T::Timer<'static>>;
 
-        fn timer(&mut self) -> Result<Self::Timer, Self::Error> {
+        fn timer(&self) -> Result<Self::Timer, Self::Error> {
             AsyncTimerService::timer(self)
         }
     }