X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Futil%2Fwakers.rs;h=e55ba37ffd84c99ba19ddc625a5cfa7e9f23ed56;hb=90c976394c3bb5726dbb6950256afcbc33ddf4a7;hp=9636466aaa2f1d750cb14b3c630aa56e4c764e2f;hpb=c6890cfc3317c0b1ba4d1e6cd71b3bb75386571e;p=rust-lightning

diff --git a/lightning/src/util/wakers.rs b/lightning/src/util/wakers.rs
index 9636466a..e55ba37f 100644
--- a/lightning/src/util/wakers.rs
+++ b/lightning/src/util/wakers.rs
@@ -15,17 +15,17 @@
 
 use alloc::sync::Arc;
 use core::mem;
-use core::time::Duration;
 use sync::{Condvar, Mutex};
 
+use 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};
 use core::pin::Pin;
 
-use prelude::*;
 
 /// Used to signal to one of many waiters that the condition they're waiting on has happened.
 pub(crate) struct Notifier {
@@ -103,7 +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 {
@@ -163,6 +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 {
@@ -172,6 +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 {
@@ -205,6 +217,20 @@ 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() {
@@ -292,7 +318,7 @@ mod tests {
 	// waker, which we do here with a trivial Arc<AtomicBool> data element to track woke-ness.
 	const WAKER_V_TABLE: RawWakerVTable = RawWakerVTable::new(waker_clone, wake, wake_by_ref, drop);
 	unsafe fn wake_by_ref(ptr: *const ()) { let p = ptr as *const Arc<AtomicBool>; assert!(!(*p).fetch_or(true, Ordering::SeqCst)); }
-	unsafe fn drop(ptr: *const ()) { let p = ptr as *mut Arc<AtomicBool>; Box::from_raw(p); }
+	unsafe fn drop(ptr: *const ()) { let p = ptr as *mut Arc<AtomicBool>; let _freed = Box::from_raw(p); }
 	unsafe fn wake(ptr: *const ()) { wake_by_ref(ptr); drop(ptr); }
 	unsafe fn waker_clone(ptr: *const ()) -> RawWaker {
 		let p = ptr as *const Arc<AtomicBool>;