Merge pull request #1625 from TheBlueMatt/2022-07-history-tracking

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

diff --git a/lightning/src/util/wakers.rs b/lightning/src/util/wakers.rs
index 7ab9aca0efe42fbc97da40c70463426595e8bc87..166771948fad62bc2f10078b5360fb67207f50f5 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 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};
@@ -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 {
@@ -293,7 +304,7 @@ 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>;