From 999807f226623669a9cfc8ca218d3c81f0c04a77 Mon Sep 17 00:00:00 2001 From: Peter Krull Date: Mon, 23 Sep 2024 20:29:50 +0200 Subject: [PATCH] Added SealedWatchBehavior to limit access to core functions --- embassy-sync/src/watch.rs | 137 ++++++++++++++++++++------------------ 1 file changed, 71 insertions(+), 66 deletions(-) diff --git a/embassy-sync/src/watch.rs b/embassy-sync/src/watch.rs index 1b4a8b589..4b7ffa5fc 100644 --- a/embassy-sync/src/watch.rs +++ b/embassy-sync/src/watch.rs @@ -76,28 +76,14 @@ struct WatchState { receiver_count: usize, } -/// A trait representing the 'inner' behavior of the `Watch`. -pub trait WatchBehavior { - /// Sends a new value to the `Watch`. - fn send(&self, val: T); - - /// Clears the value of the `Watch`. - fn clear(&self); - +trait SealedWatchBehavior { /// Poll the `Watch` for the current value, making it as seen. fn poll_get(&self, id: &mut u64, cx: &mut Context<'_>) -> Poll; - /// Tries to get the value of the `Watch`, marking it as seen, if an id is given. - fn try_get(&self, id: Option<&mut u64>) -> Option; - /// Poll the `Watch` for the value if it matches the predicate function /// `f`, making it as seen. fn poll_get_and(&self, id: &mut u64, f: &mut dyn Fn(&T) -> bool, cx: &mut Context<'_>) -> Poll; - /// Tries to get the value of the `Watch` if it matches the predicate function - /// `f`, marking it as seen. - fn try_get_and(&self, id: Option<&mut u64>, f: &mut dyn Fn(&T) -> bool) -> Option; - /// Poll the `Watch` for a changed value, marking it as seen, if an id is given. fn poll_changed(&self, id: &mut u64, cx: &mut Context<'_>) -> Poll; @@ -112,8 +98,16 @@ pub trait WatchBehavior { /// predicate function `f`, marking it as seen. fn try_changed_and(&self, id: &mut u64, f: &mut dyn Fn(&T) -> bool) -> Option; - /// Checks if the `Watch` is been initialized with a value. - fn contains_value(&self) -> bool; + /// Used when a receiver is dropped to decrement the receiver count. + /// + /// ## This method should not be called by the user. + fn drop_receiver(&self); + + /// Clears the value of the `Watch`. + fn clear(&self); + + /// Sends a new value to the `Watch`. + fn send(&self, val: T); /// Modify the value of the `Watch` using a closure. Returns `false` if the /// `Watch` does not already contain a value. @@ -122,30 +116,23 @@ pub trait WatchBehavior { /// Modify the value of the `Watch` using a closure. Returns `false` if the /// `Watch` does not already contain a value. fn send_if_modified(&self, f: &mut dyn Fn(&mut Option) -> bool); - - /// Used when a receiver is dropped to decrement the receiver count. - /// - /// ## This method should not be called by the user. - fn drop_receiver(&self); } -impl WatchBehavior for Watch { - fn send(&self, val: T) { - self.mutex.lock(|state| { - let mut s = state.borrow_mut(); - s.data = Some(val); - s.current_id += 1; - s.wakers.wake(); - }) - } +/// A trait representing the 'inner' behavior of the `Watch`. +#[allow(private_bounds)] +pub trait WatchBehavior: SealedWatchBehavior { + /// Tries to get the value of the `Watch`, marking it as seen, if an id is given. + fn try_get(&self, id: Option<&mut u64>) -> Option; - fn clear(&self) { - self.mutex.lock(|state| { - let mut s = state.borrow_mut(); - s.data = None; - }) - } + /// Tries to get the value of the `Watch` if it matches the predicate function + /// `f`, marking it as seen. + fn try_get_and(&self, id: Option<&mut u64>, f: &mut dyn Fn(&T) -> bool) -> Option; + /// Checks if the `Watch` is been initialized with a value. + fn contains_value(&self) -> bool; +} + +impl SealedWatchBehavior for Watch { fn poll_get(&self, id: &mut u64, cx: &mut Context<'_>) -> Poll { self.mutex.lock(|state| { let mut s = state.borrow_mut(); @@ -162,16 +149,6 @@ impl WatchBehavior for Watch }) } - fn try_get(&self, id: Option<&mut u64>) -> Option { - self.mutex.lock(|state| { - let s = state.borrow(); - if let Some(id) = id { - *id = s.current_id; - } - s.data.clone() - }) - } - fn poll_get_and(&self, id: &mut u64, f: &mut dyn Fn(&T) -> bool, cx: &mut Context<'_>) -> Poll { self.mutex.lock(|state| { let mut s = state.borrow_mut(); @@ -188,21 +165,6 @@ impl WatchBehavior for Watch }) } - fn try_get_and(&self, id: Option<&mut u64>, f: &mut dyn Fn(&T) -> bool) -> Option { - self.mutex.lock(|state| { - let s = state.borrow(); - match s.data { - Some(ref data) if f(data) => { - if let Some(id) = id { - *id = s.current_id; - } - Some(data.clone()) - } - _ => None, - } - }) - } - fn poll_changed(&self, id: &mut u64, cx: &mut Context<'_>) -> Poll { self.mutex.lock(|state| { let mut s = state.borrow_mut(); @@ -261,10 +223,6 @@ impl WatchBehavior for Watch }) } - fn contains_value(&self) -> bool { - self.mutex.lock(|state| state.borrow().data.is_some()) - } - fn drop_receiver(&self) { self.mutex.lock(|state| { let mut s = state.borrow_mut(); @@ -272,6 +230,22 @@ impl WatchBehavior for Watch }) } + fn clear(&self) { + self.mutex.lock(|state| { + let mut s = state.borrow_mut(); + s.data = None; + }) + } + + fn send(&self, val: T) { + self.mutex.lock(|state| { + let mut s = state.borrow_mut(); + s.data = Some(val); + s.current_id += 1; + s.wakers.wake(); + }) + } + fn send_modify(&self, f: &mut dyn Fn(&mut Option)) { self.mutex.lock(|state| { let mut s = state.borrow_mut(); @@ -292,6 +266,37 @@ impl WatchBehavior for Watch } } +impl WatchBehavior for Watch { + fn try_get(&self, id: Option<&mut u64>) -> Option { + self.mutex.lock(|state| { + let s = state.borrow(); + if let Some(id) = id { + *id = s.current_id; + } + s.data.clone() + }) + } + + fn try_get_and(&self, id: Option<&mut u64>, f: &mut dyn Fn(&T) -> bool) -> Option { + self.mutex.lock(|state| { + let s = state.borrow(); + match s.data { + Some(ref data) if f(data) => { + if let Some(id) = id { + *id = s.current_id; + } + Some(data.clone()) + } + _ => None, + } + }) + } + + fn contains_value(&self) -> bool { + self.mutex.lock(|state| state.borrow().data.is_some()) + } +} + impl Watch { /// Create a new `Watch` channel. pub const fn new() -> Self {