Add async api

Author: joostjager

Diff for: lightning-background-processor/src/lib.rs

@@ -313,7 +313,7 @@ macro_rules! define_run_body {
 		$channel_manager: ident, $process_channel_manager_events: expr,
 		$onion_messenger: ident, $process_onion_message_handler_events: expr,
 		$peer_manager: ident, $gossip_sync: ident,
-		$sweeper: ident,
+		$sweeper: expr,
 		$logger: ident, $scorer: ident, $loop_exit_check: expr, $await: expr, $get_timer: expr,
 		$timer_elapsed: expr, $check_slow_await: expr, $time_fetch: expr,
 	) => { {
@@ -473,7 +473,7 @@ macro_rules! define_run_body {
 
 			if $timer_elapsed(&mut last_sweeper_call, SWEEPER_TIMER) {
 				log_trace!($logger, "Regenerate sweeper spends if necessary");
-				let _ = $sweeper.regenerate_and_broadcast_spend_if_necessary_locked();
+				let _ = $sweeper;
 				last_sweeper_call = $get_timer(SWEEPER_TIMER);
 			}
 		}
@@ -602,7 +602,7 @@ pub(crate) mod futures_util {
 	}
 }
 #[cfg(feature = "futures")]
-use core::task;
+use core::{task, future::Future};
 #[cfg(feature = "futures")]
 use futures_util::{dummy_waker, OptionalSelector, Selector, SelectorOutput};
 
@@ -757,6 +757,10 @@ pub async fn process_events_async<
 		+ Sync,
 	CM: 'static + Deref + Send + Sync,
 	OM: 'static + Deref + Send + Sync,
+	D: 'static + Deref + Send + Sync,
+	O: 'static + Deref + Send + Sync,
+	K: 'static + Deref + Send + Sync,
+	OS: 'static + Deref<Target = OutputSweeper<T, D, F, CF, K, L, O>> + Send + Sync,
 	PGS: 'static + Deref<Target = P2PGossipSync<G, UL, L>> + Send + Sync,
 	RGS: 'static + Deref<Target = RapidGossipSync<G, L>> + Send,
 	PM: 'static + Deref + Send + Sync,
@@ -768,12 +772,13 @@ pub async fn process_events_async<
 >(
 	persister: PS, event_handler: EventHandler, chain_monitor: M, channel_manager: CM,
 	onion_messenger: Option<OM>, gossip_sync: GossipSync<PGS, RGS, G, UL, L>, peer_manager: PM,
+	sweeper: OS,
 	logger: L, scorer: Option<S>, sleeper: Sleeper, mobile_interruptable_platform: bool,
 	fetch_time: FetchTime,
 ) -> Result<(), lightning::io::Error>
 where
 	UL::Target: 'static + UtxoLookup,
-	CF::Target: 'static + chain::Filter,
+	CF::Target: 'static + chain::Filter + Sync + Send,
 	T::Target: 'static + BroadcasterInterface,
 	F::Target: 'static + FeeEstimator,
 	L::Target: 'static + Logger,
@@ -782,6 +787,9 @@ where
 	CM::Target: AChannelManager + Send + Sync,
 	OM::Target: AOnionMessenger + Send + Sync,
 	PM::Target: APeerManager + Send + Sync,
+	O::Target: 'static + OutputSpender + Send + Sync,
+	D::Target: 'static + ChangeDestinationSource + Send + Sync,
+	K::Target: 'static + KVStore + Send + Sync,
 {
 	let mut should_break = false;
 	let async_event_handler = |event| {
@@ -825,6 +833,7 @@ where
 		},
 		peer_manager,
 		gossip_sync,
+		sweeper.regenerate_and_broadcast_spend_if_necessary_async().await,
 		logger,
 		scorer,
 		should_break,
@@ -995,7 +1004,7 @@ impl BackgroundProcessor {
 				},
 				peer_manager,
 				gossip_sync,
-				sweeper,
+				sweeper.regenerate_and_broadcast_spend_if_necessary(),
 				logger,
 				scorer,
 				stop_thread.load(Ordering::Acquire),
@@ -1108,8 +1117,7 @@ mod tests {
 	use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
 	use lightning::routing::router::{CandidateRouteHop, DefaultRouter, Path, RouteHop};
 	use lightning::routing::scoring::{ChannelUsage, LockableScore, ScoreLookUp, ScoreUpdate};
-	use lightning::routing::utxo::UtxoLookup;
-	use lightning::sign::{ChangeDestinationSource, InMemorySigner, KeysManager};
+	use lightning::sign::{AsyncGetChangeDestinationScriptResult, ChangeDestinationSource, InMemorySigner, KeysManager};
 	use lightning::types::features::{ChannelFeatures, NodeFeatures};
 	use lightning::types::payment::PaymentHash;
 	use lightning::util::config::UserConfig;
@@ -1544,8 +1552,10 @@ mod tests {
 	struct TestWallet {}
 
 	impl ChangeDestinationSource for TestWallet {
-		fn get_change_destination_script(&self) -> Result<ScriptBuf, ()> {
-			Ok(ScriptBuf::new())
+		fn get_change_destination_script<'a>(&self) -> AsyncGetChangeDestinationScriptResult<'a, ScriptBuf> {
+			Box::pin(async move {
+				Ok(ScriptBuf::new())
+			})
 		}
 	}
 
@@ -2027,6 +2037,7 @@ mod tests {
 			Some(nodes[0].messenger.clone()),
 			nodes[0].rapid_gossip_sync(),
 			nodes[0].peer_manager.clone(),
+			nodes[0].sweeper.clone(),
 			nodes[0].logger.clone(),
 			Some(nodes[0].scorer.clone()),
 			move |dur: Duration| {
@@ -2514,6 +2525,7 @@ mod tests {
 			Some(nodes[0].messenger.clone()),
 			nodes[0].rapid_gossip_sync(),
 			nodes[0].peer_manager.clone(),
+			nodes[0].sweeper.clone(),
 			nodes[0].logger.clone(),
 			Some(nodes[0].scorer.clone()),
 			move |dur: Duration| {
@@ -2727,6 +2739,7 @@ mod tests {
 			Some(nodes[0].messenger.clone()),
 			nodes[0].no_gossip_sync(),
 			nodes[0].peer_manager.clone(),
+			nodes[0].sweeper.clone(),
 			nodes[0].logger.clone(),
 			Some(nodes[0].scorer.clone()),
 			move |dur: Duration| {

Diff for: lightning/src/lib.rs

@@ -30,7 +30,6 @@
 //! * `grind_signatures`
 
 #![cfg_attr(not(any(test, fuzzing, feature = "_test_utils")), deny(missing_docs))]
-#![cfg_attr(not(any(test, feature = "_test_utils")), forbid(unsafe_code))]
 
 #![deny(rustdoc::broken_intra_doc_links)]
 #![deny(rustdoc::private_intra_doc_links)]

Diff for: lightning/src/sign/mod.rs

@@ -67,6 +67,8 @@ use crate::sign::ecdsa::EcdsaChannelSigner;
 use crate::sign::taproot::TaprootChannelSigner;
 use crate::util::atomic_counter::AtomicCounter;
 use core::convert::TryInto;
+use core::future::Future;
+use core::pin::Pin;
 use core::sync::atomic::{AtomicUsize, Ordering};
 #[cfg(taproot)]
 use musig2::types::{PartialSignature, PublicNonce};
@@ -975,17 +977,43 @@ pub trait SignerProvider {
 	fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()>;
 }
 
+
+/// Result type for `BlockSource` requests.
+pub type GetChangeDestinationScriptResult<T> = Result<T, ()>;
+
+/// A type alias for a future that returns a [`GetChangeDestinationScriptResult`].
+pub type AsyncGetChangeDestinationScriptResult<'a, T> =
+	Pin<Box<dyn Future<Output = GetChangeDestinationScriptResult<T>> + 'a + Send>>;
+
 /// A helper trait that describes an on-chain wallet capable of returning a (change) destination
 /// script.
 pub trait ChangeDestinationSource {
 	/// Returns a script pubkey which can be used as a change destination for
 	/// [`OutputSpender::spend_spendable_outputs`].
 	///
+	/// This method should return a different value each time it is called, to avoid linking
+	/// on-chain funds controlled to the same user.
+	fn get_change_destination_script<'a>(&self) -> AsyncGetChangeDestinationScriptResult<'a, ScriptBuf>;
+}
+
+
+/// A synchronous helper trait that describes an on-chain wallet capable of returning a (change) destination script.
+pub trait ChangeDestinationSourceSync {
 	/// This method should return a different value each time it is called, to avoid linking
 	/// on-chain funds controlled to the same user.
 	fn get_change_destination_script(&self) -> Result<ScriptBuf, ()>;
 }
 
+/// A wrapper around [`ChangeDestinationSource`] to allow for async calls.
+pub struct ChangeDestinationSourceSyncWrapper<T>(T) where T: ChangeDestinationSourceSync;
+
+impl<T: ChangeDestinationSourceSync> ChangeDestinationSource for ChangeDestinationSourceSyncWrapper<T> {
+	fn get_change_destination_script<'a>(&self) -> AsyncGetChangeDestinationScriptResult<'a, ScriptBuf> {
+		let script = self.0.get_change_destination_script();
+		Box::pin(async move { script })
+	}
+}
+
 mod sealed {
 	use bitcoin::secp256k1::{Scalar, SecretKey};
 

Diff for: lightning/src/util/async_poll.rs

@@ -13,7 +13,7 @@ use crate::prelude::*;
 use core::future::Future;
 use core::marker::Unpin;
 use core::pin::Pin;
-use core::task::{Context, Poll};
+use core::task::{Context, Poll, RawWaker, RawWakerVTable, Waker};
 
 pub(crate) enum ResultFuture<F: Future<Output = Result<(), E>>, E: Copy + Unpin> {
 	Pending(F),
@@ -74,3 +74,22 @@ impl<F: Future<Output = Result<(), E>> + Unpin, E: Copy + Unpin> Future
 		}
 	}
 }
+
+// If we want to poll a future without an async context to figure out if it has completed or
+// not without awaiting, we need a Waker, which needs a vtable...we fill it with dummy values
+// but sadly there's a good bit of boilerplate here.
+fn dummy_waker_clone(_: *const ()) -> RawWaker {
+	RawWaker::new(core::ptr::null(), &DUMMY_WAKER_VTABLE)
+}
+fn dummy_waker_action(_: *const ()) {}
+
+const DUMMY_WAKER_VTABLE: RawWakerVTable = RawWakerVTable::new(
+	dummy_waker_clone,
+	dummy_waker_action,
+	dummy_waker_action,
+	dummy_waker_action,
+);
+
+pub(crate) fn dummy_waker() -> Waker {
+	unsafe { Waker::from_raw(RawWaker::new(core::ptr::null(), &DUMMY_WAKER_VTABLE)) }
+}