Merge pull request #1735 from naumenkogs/2022-09-prune-channels-if-either-not-upd

[rust-lightning] / lightning / src / util / wakers.rs

diff --git a/lightning/src/util/wakers.rs b/lightning/src/util/wakers.rs
index 01012fff7900820251057045f6353d301186eae9..8eb6c25c6189b6aa27dcc62266dc9a40b709f689 100644 (file)
--- a/lightning/src/util/wakers.rs
+++ b/lightning/src/util/wakers.rs
@@ -15,13 +15,12 @@
 
 use alloc::sync::Arc;
 use core::mem;
-use core::time::Duration;
-use sync::{Condvar, Mutex};
+use crate::sync::{Condvar, Mutex};
 
-use prelude::*;
+use crate::prelude::*;
 
 #[cfg(any(test, feature = "std"))]
-use std::time::Instant;
+use std::time::{Duration, Instant};
 
 use core::future::Future as StdFuture;
 use core::task::{Context, Poll};
@@ -104,7 +103,7 @@ impl Notifier {
                        Future {
                                state: Arc::new(Mutex::new(FutureState {
                                        callbacks: Vec::new(),
-                                       complete: false,
+                                       complete: true,
                                }))
                        }
                } else if let Some(existing_state) = &lock.1 {
@@ -164,6 +163,8 @@ pub struct Future {
 impl Future {
        /// Registers a callback to be called upon completion of this future. If the future has already
        /// completed, the callback will be called immediately.
+       ///
+       /// (C-not exported) use the bindings-only `register_callback_fn` instead
        pub fn register_callback(&self, callback: Box<dyn FutureCallback>) {
                let mut state = self.state.lock().unwrap();
                if state.complete {
@@ -173,6 +174,16 @@ impl Future {
                        state.callbacks.push(callback);
                }
        }
+
+       // C bindings don't (currently) know how to map `Box<dyn Trait>`, and while it could add the
+       // following wrapper, doing it in the bindings is currently much more work than simply doing it
+       // here.
+       /// Registers a callback to be called upon completion of this future. If the future has already
+       /// completed, the callback will be called immediately.
+       #[cfg(c_bindings)]
+       pub fn register_callback_fn<F: 'static + FutureCallback>(&self, callback: F) {
+               self.register_callback(Box::new(callback));
+       }
 }
 
 mod std_future {
@@ -206,10 +217,24 @@ mod tests {
        use core::future::Future as FutureTrait;
        use core::task::{Context, Poll, RawWaker, RawWakerVTable, Waker};
 
+       #[test]
+       fn notifier_pre_notified_future() {
+               // Previously, if we generated a future after a `Notifier` had been notified, the future
+               // would never complete. This tests this behavior, ensuring the future instead completes
+               // immediately.
+               let notifier = Notifier::new();
+               notifier.notify();
+
+               let callback = Arc::new(AtomicBool::new(false));
+               let callback_ref = Arc::clone(&callback);
+               notifier.get_future().register_callback(Box::new(move || assert!(!callback_ref.fetch_or(true, Ordering::SeqCst))));
+               assert!(callback.load(Ordering::SeqCst));
+       }
+
        #[cfg(feature = "std")]
        #[test]
        fn test_wait_timeout() {
-               use sync::Arc;
+               use crate::sync::Arc;
                use std::thread;
 
                let persistence_notifier = Arc::new(Notifier::new());