Merge pull request #2023 from futurepaul/fallback-to-address
[rust-lightning] / lightning-background-processor / src / lib.rs
index 51d8a7f866f9046ab24268ec60ce398ef5acfaf0..21e9d419471ee6cc5fb619a0480642600096513c 100644 (file)
@@ -7,7 +7,7 @@
 #![deny(private_intra_doc_links)]
 
 #![deny(missing_docs)]
-#![deny(unsafe_code)]
+#![cfg_attr(not(feature = "futures"), deny(unsafe_code))]
 
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 
@@ -26,6 +26,9 @@ use lightning::chain;
 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use lightning::chain::chainmonitor::{ChainMonitor, Persist};
 use lightning::chain::keysinterface::{EntropySource, NodeSigner, SignerProvider};
+use lightning::events::{Event, PathFailure};
+#[cfg(feature = "std")]
+use lightning::events::{EventHandler, EventsProvider};
 use lightning::ln::channelmanager::ChannelManager;
 use lightning::ln::msgs::{ChannelMessageHandler, OnionMessageHandler, RoutingMessageHandler};
 use lightning::ln::peer_handler::{CustomMessageHandler, PeerManager, SocketDescriptor};
@@ -33,11 +36,11 @@ use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
 use lightning::routing::utxo::UtxoLookup;
 use lightning::routing::router::Router;
 use lightning::routing::scoring::{Score, WriteableScore};
-use lightning::util::events::{Event, EventHandler, EventsProvider, PathFailure};
 use lightning::util::logger::Logger;
 use lightning::util::persist::Persister;
+#[cfg(feature = "std")]
+use lightning::util::wakers::Sleeper;
 use lightning_rapid_gossip_sync::RapidGossipSync;
-use lightning::io;
 
 use core::ops::Deref;
 use core::time::Duration;
@@ -51,8 +54,6 @@ use std::thread::{self, JoinHandle};
 #[cfg(feature = "std")]
 use std::time::Instant;
 
-#[cfg(feature = "futures")]
-use futures_util::{select_biased, future::FutureExt, task};
 #[cfg(not(feature = "std"))]
 use alloc::vec::Vec;
 
@@ -79,7 +80,7 @@ use alloc::vec::Vec;
 /// unilateral chain closure fees are at risk.
 ///
 /// [`ChannelMonitor`]: lightning::chain::channelmonitor::ChannelMonitor
-/// [`Event`]: lightning::util::events::Event
+/// [`Event`]: lightning::events::Event
 #[cfg(feature = "std")]
 #[must_use = "BackgroundProcessor will immediately stop on drop. It should be stored until shutdown."]
 pub struct BackgroundProcessor {
@@ -115,6 +116,13 @@ const FIRST_NETWORK_PRUNE_TIMER: u64 = 60;
 #[cfg(test)]
 const FIRST_NETWORK_PRUNE_TIMER: u64 = 1;
 
+#[cfg(feature = "futures")]
+/// core::cmp::min is not currently const, so we define a trivial (and equivalent) replacement
+const fn min_u64(a: u64, b: u64) -> u64 { if a < b { a } else { b } }
+#[cfg(feature = "futures")]
+const FASTEST_TIMER: u64 = min_u64(min_u64(FRESHNESS_TIMER, PING_TIMER),
+       min_u64(SCORER_PERSIST_TIMER, FIRST_NETWORK_PRUNE_TIMER));
+
 /// Either [`P2PGossipSync`] or [`RapidGossipSync`].
 pub enum GossipSync<
        P: Deref<Target = P2PGossipSync<G, U, L>>,
@@ -163,7 +171,7 @@ where U::Target: UtxoLookup, L::Target: Logger {
        }
 }
 
-/// (C-not exported) as the bindings concretize everything and have constructors for us
+/// This is not exported to bindings users as the bindings concretize everything and have constructors for us
 impl<P: Deref<Target = P2PGossipSync<G, U, L>>, G: Deref<Target = NetworkGraph<L>>, U: Deref, L: Deref>
        GossipSync<P, &RapidGossipSync<G, L>, G, U, L>
 where
@@ -176,7 +184,7 @@ where
        }
 }
 
-/// (C-not exported) as the bindings concretize everything and have constructors for us
+/// This is not exported to bindings users as the bindings concretize everything and have constructors for us
 impl<'a, R: Deref<Target = RapidGossipSync<G, L>>, G: Deref<Target = NetworkGraph<L>>, L: Deref>
        GossipSync<
                &P2PGossipSync<G, &'a (dyn UtxoLookup + Send + Sync), L>,
@@ -194,7 +202,7 @@ where
        }
 }
 
-/// (C-not exported) as the bindings concretize everything and have constructors for us
+/// This is not exported to bindings users as the bindings concretize everything and have constructors for us
 impl<'a, L: Deref>
        GossipSync<
                &P2PGossipSync<&'a NetworkGraph<L>, &'a (dyn UtxoLookup + Send + Sync), L>,
@@ -257,7 +265,8 @@ macro_rules! define_run_body {
        ($persister: ident, $chain_monitor: ident, $process_chain_monitor_events: expr,
         $channel_manager: ident, $process_channel_manager_events: expr,
         $gossip_sync: ident, $peer_manager: ident, $logger: ident, $scorer: ident,
-        $loop_exit_check: expr, $await: expr, $get_timer: expr, $timer_elapsed: expr)
+        $loop_exit_check: expr, $await: expr, $get_timer: expr, $timer_elapsed: expr,
+        $check_slow_await: expr)
        => { {
                log_trace!($logger, "Calling ChannelManager's timer_tick_occurred on startup");
                $channel_manager.timer_tick_occurred();
@@ -287,9 +296,10 @@ macro_rules! define_run_body {
 
                        // We wait up to 100ms, but track how long it takes to detect being put to sleep,
                        // see `await_start`'s use below.
-                       let mut await_start = $get_timer(1);
+                       let mut await_start = None;
+                       if $check_slow_await { await_start = Some($get_timer(1)); }
                        let updates_available = $await;
-                       let await_slow = $timer_elapsed(&mut await_start, 1);
+                       let await_slow = if $check_slow_await { $timer_elapsed(&mut await_start.unwrap(), 1) } else { false };
 
                        if updates_available {
                                log_trace!($logger, "Persisting ChannelManager...");
@@ -348,9 +358,9 @@ macro_rules! define_run_body {
                                                log_error!($logger, "Error: Failed to persist network graph, check your disk and permissions {}", e)
                                        }
 
-                                       last_prune_call = $get_timer(NETWORK_PRUNE_TIMER);
                                        have_pruned = true;
                                }
+                               last_prune_call = $get_timer(NETWORK_PRUNE_TIMER);
                        }
 
                        if $timer_elapsed(&mut last_scorer_persist_call, SCORER_PERSIST_TIMER) {
@@ -383,6 +393,59 @@ macro_rules! define_run_body {
        } }
 }
 
+#[cfg(feature = "futures")]
+pub(crate) mod futures_util {
+       use core::future::Future;
+       use core::task::{Poll, Waker, RawWaker, RawWakerVTable};
+       use core::pin::Pin;
+       use core::marker::Unpin;
+       pub(crate) struct Selector<
+               A: Future<Output=()> + Unpin, B: Future<Output=()> + Unpin, C: Future<Output=bool> + Unpin
+       > {
+               pub a: A,
+               pub b: B,
+               pub c: C,
+       }
+       pub(crate) enum SelectorOutput {
+               A, B, C(bool),
+       }
+
+       impl<
+               A: Future<Output=()> + Unpin, B: Future<Output=()> + Unpin, C: Future<Output=bool> + Unpin
+       > Future for Selector<A, B, C> {
+               type Output = SelectorOutput;
+               fn poll(mut self: Pin<&mut Self>, ctx: &mut core::task::Context<'_>) -> Poll<SelectorOutput> {
+                       match Pin::new(&mut self.a).poll(ctx) {
+                               Poll::Ready(()) => { return Poll::Ready(SelectorOutput::A); },
+                               Poll::Pending => {},
+                       }
+                       match Pin::new(&mut self.b).poll(ctx) {
+                               Poll::Ready(()) => { return Poll::Ready(SelectorOutput::B); },
+                               Poll::Pending => {},
+                       }
+                       match Pin::new(&mut self.c).poll(ctx) {
+                               Poll::Ready(res) => { return Poll::Ready(SelectorOutput::C(res)); },
+                               Poll::Pending => {},
+                       }
+                       Poll::Pending
+               }
+       }
+
+       // 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)) } }
+}
+#[cfg(feature = "futures")]
+use futures_util::{Selector, SelectorOutput, dummy_waker};
+#[cfg(feature = "futures")]
+use core::task;
+
 /// Processes background events in a future.
 ///
 /// `sleeper` should return a future which completes in the given amount of time and returns a
@@ -395,6 +458,11 @@ macro_rules! define_run_body {
 /// feature, doing so will skip calling [`NetworkGraph::remove_stale_channels_and_tracking`],
 /// you should call [`NetworkGraph::remove_stale_channels_and_tracking_with_time`] regularly
 /// manually instead.
+///
+/// The `mobile_interruptable_platform` flag should be set if we're currently running on a
+/// mobile device, where we may need to check for interruption of the application regularly. If you
+/// are unsure, you should set the flag, as the performance impact of it is minimal unless there
+/// are hundreds or thousands of simultaneous process calls running.
 #[cfg(feature = "futures")]
 pub async fn process_events_async<
        'a,
@@ -430,8 +498,8 @@ pub async fn process_events_async<
 >(
        persister: PS, event_handler: EventHandler, chain_monitor: M, channel_manager: CM,
        gossip_sync: GossipSync<PGS, RGS, G, UL, L>, peer_manager: PM, logger: L, scorer: Option<S>,
-       sleeper: Sleeper,
-) -> Result<(), io::Error>
+       sleeper: Sleeper, mobile_interruptable_platform: bool,
+) -> Result<(), lightning::io::Error>
 where
        UL::Target: 'static + UtxoLookup,
        CF::Target: 'static + chain::Filter,
@@ -450,7 +518,7 @@ where
        UMH::Target: 'static + CustomMessageHandler,
        PS::Target: 'static + Persister<'a, CW, T, ES, NS, SP, F, R, L, SC>,
 {
-       let mut should_break = true;
+       let mut should_break = false;
        let async_event_handler = |event| {
                let network_graph = gossip_sync.network_graph();
                let event_handler = &event_handler;
@@ -469,19 +537,28 @@ where
                chain_monitor, chain_monitor.process_pending_events_async(async_event_handler).await,
                channel_manager, channel_manager.process_pending_events_async(async_event_handler).await,
                gossip_sync, peer_manager, logger, scorer, should_break, {
-                       select_biased! {
-                               _ = channel_manager.get_persistable_update_future().fuse() => true,
-                               exit = sleeper(Duration::from_millis(100)).fuse() => {
+                       let fut = Selector {
+                               a: channel_manager.get_persistable_update_future(),
+                               b: chain_monitor.get_update_future(),
+                               c: sleeper(if mobile_interruptable_platform { Duration::from_millis(100) } else { Duration::from_secs(FASTEST_TIMER) }),
+                       };
+                       match fut.await {
+                               SelectorOutput::A => true,
+                               SelectorOutput::B => false,
+                               SelectorOutput::C(exit) => {
                                        should_break = exit;
                                        false
                                }
                        }
                }, |t| sleeper(Duration::from_secs(t)),
                |fut: &mut SleepFuture, _| {
-                       let mut waker = task::noop_waker();
+                       let mut waker = dummy_waker();
                        let mut ctx = task::Context::from_waker(&mut waker);
-                       core::pin::Pin::new(fut).poll(&mut ctx).is_ready()
-               })
+                       match core::pin::Pin::new(fut).poll(&mut ctx) {
+                               task::Poll::Ready(exit) => { should_break = exit; true },
+                               task::Poll::Pending => false,
+                       }
+               }, mobile_interruptable_platform)
 }
 
 #[cfg(feature = "std")]
@@ -596,8 +673,11 @@ impl BackgroundProcessor {
                        define_run_body!(persister, chain_monitor, chain_monitor.process_pending_events(&event_handler),
                                channel_manager, channel_manager.process_pending_events(&event_handler),
                                gossip_sync, peer_manager, logger, scorer, stop_thread.load(Ordering::Acquire),
-                               channel_manager.await_persistable_update_timeout(Duration::from_millis(100)),
-                               |_| Instant::now(), |time: &Instant, dur| time.elapsed().as_secs() > dur)
+                               Sleeper::from_two_futures(
+                                       channel_manager.get_persistable_update_future(),
+                                       chain_monitor.get_update_future()
+                               ).wait_timeout(Duration::from_millis(100)),
+                               |_| Instant::now(), |time: &Instant, dur| time.elapsed().as_secs() > dur, false)
                });
                Self { stop_thread: stop_thread_clone, thread_handle: Some(handle) }
        }
@@ -662,7 +742,8 @@ mod tests {
        use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
        use lightning::chain::keysinterface::{InMemorySigner, KeysManager};
        use lightning::chain::transaction::OutPoint;
-       use lightning::get_event_msg;
+       use lightning::events::{Event, PathFailure, MessageSendEventsProvider, MessageSendEvent};
+       use lightning::{get_event_msg, get_event};
        use lightning::ln::PaymentHash;
        use lightning::ln::channelmanager;
        use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, ChainParameters, MIN_CLTV_EXPIRY_DELTA, PaymentId};
@@ -673,7 +754,6 @@ mod tests {
        use lightning::routing::router::{DefaultRouter, RouteHop};
        use lightning::routing::scoring::{ChannelUsage, Score};
        use lightning::util::config::UserConfig;
-       use lightning::util::events::{Event, PathFailure, MessageSendEventsProvider, MessageSendEvent};
        use lightning::util::ser::Writeable;
        use lightning::util::test_utils;
        use lightning::util::persist::KVStorePersister;
@@ -756,7 +836,7 @@ mod tests {
 
        impl Persister {
                fn new(data_dir: String) -> Self {
-                       let filesystem_persister = FilesystemPersister::new(data_dir.clone());
+                       let filesystem_persister = FilesystemPersister::new(data_dir);
                        Self { graph_error: None, graph_persistence_notifier: None, manager_error: None, scorer_error: None, filesystem_persister }
                }
 
@@ -823,7 +903,7 @@ mod tests {
                }
 
                fn expect(&mut self, expectation: TestResult) {
-                       self.event_expectations.get_or_insert_with(|| VecDeque::new()).push_back(expectation);
+                       self.event_expectations.get_or_insert_with(VecDeque::new).push_back(expectation);
                }
        }
 
@@ -941,7 +1021,7 @@ mod tests {
                        let logger = Arc::new(test_utils::TestLogger::with_id(format!("node {}", i)));
                        let network = Network::Testnet;
                        let genesis_block = genesis_block(network);
-                       let network_graph = Arc::new(NetworkGraph::new(genesis_block.header.block_hash(), logger.clone()));
+                       let network_graph = Arc::new(NetworkGraph::new(network, logger.clone()));
                        let scorer = Arc::new(Mutex::new(TestScorer::new()));
                        let seed = [i as u8; 32];
                        let router = Arc::new(DefaultRouter::new(network_graph.clone(), logger.clone(), seed, scorer.clone()));
@@ -950,11 +1030,11 @@ mod tests {
                        let now = Duration::from_secs(genesis_block.header.time as u64);
                        let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_nanos()));
                        let chain_monitor = Arc::new(chainmonitor::ChainMonitor::new(Some(chain_source.clone()), tx_broadcaster.clone(), logger.clone(), fee_estimator.clone(), persister.clone()));
-                       let best_block = BestBlock::from_genesis(network);
+                       let best_block = BestBlock::from_network(network);
                        let params = ChainParameters { network, best_block };
                        let manager = Arc::new(ChannelManager::new(fee_estimator.clone(), chain_monitor.clone(), tx_broadcaster.clone(), router.clone(), logger.clone(), keys_manager.clone(), keys_manager.clone(), keys_manager.clone(), UserConfig::default(), params));
                        let p2p_gossip_sync = Arc::new(P2PGossipSync::new(network_graph.clone(), Some(chain_source.clone()), logger.clone()));
-                       let rapid_gossip_sync = Arc::new(RapidGossipSync::new(network_graph.clone()));
+                       let rapid_gossip_sync = Arc::new(RapidGossipSync::new(network_graph.clone(), logger.clone()));
                        let msg_handler = MessageHandler { chan_handler: Arc::new(test_utils::TestChannelMessageHandler::new()), route_handler: Arc::new(test_utils::TestRoutingMessageHandler::new()), onion_message_handler: IgnoringMessageHandler{}};
                        let peer_manager = Arc::new(PeerManager::new(msg_handler, 0, &seed, logger.clone(), IgnoringMessageHandler{}, keys_manager.clone()));
                        let node = Node { node: manager, p2p_gossip_sync, rapid_gossip_sync, peer_manager, chain_monitor, persister, tx_broadcaster, network_graph, logger, best_block, scorer };
@@ -977,7 +1057,11 @@ mod tests {
                        let events = $node_a.node.get_and_clear_pending_events();
                        assert_eq!(events.len(), 1);
                        let (temporary_channel_id, tx) = handle_funding_generation_ready!(events[0], $channel_value);
-                       end_open_channel!($node_a, $node_b, temporary_channel_id, tx);
+                       $node_a.node.funding_transaction_generated(&temporary_channel_id, &$node_b.node.get_our_node_id(), tx.clone()).unwrap();
+                       $node_b.node.handle_funding_created(&$node_a.node.get_our_node_id(), &get_event_msg!($node_a, MessageSendEvent::SendFundingCreated, $node_b.node.get_our_node_id()));
+                       get_event!($node_b, Event::ChannelPending);
+                       $node_a.node.handle_funding_signed(&$node_b.node.get_our_node_id(), &get_event_msg!($node_b, MessageSendEvent::SendFundingSigned, $node_a.node.get_our_node_id()));
+                       get_event!($node_a, Event::ChannelPending);
                        tx
                }}
        }
@@ -1007,14 +1091,6 @@ mod tests {
                }}
        }
 
-       macro_rules! end_open_channel {
-               ($node_a: expr, $node_b: expr, $temporary_channel_id: expr, $tx: expr) => {{
-                       $node_a.node.funding_transaction_generated(&$temporary_channel_id, &$node_b.node.get_our_node_id(), $tx.clone()).unwrap();
-                       $node_b.node.handle_funding_created(&$node_a.node.get_our_node_id(), &get_event_msg!($node_a, MessageSendEvent::SendFundingCreated, $node_b.node.get_our_node_id()));
-                       $node_a.node.handle_funding_signed(&$node_b.node.get_our_node_id(), &get_event_msg!($node_b, MessageSendEvent::SendFundingSigned, $node_a.node.get_our_node_id()));
-               }}
-       }
-
        fn confirm_transaction_depth(node: &mut Node, tx: &Transaction, depth: u32) {
                for i in 1..=depth {
                        let prev_blockhash = node.best_block.block_hash();
@@ -1106,7 +1182,9 @@ mod tests {
                let filepath = get_full_filepath("test_background_processor_persister_0".to_string(), "scorer".to_string());
                check_persisted_data!(nodes[0].scorer, filepath.clone());
 
-               assert!(bg_processor.stop().is_ok());
+               if !std::thread::panicking() {
+                       bg_processor.stop().unwrap();
+               }
        }
 
        #[test]
@@ -1128,7 +1206,9 @@ mod tests {
                        }
                }
 
-               assert!(bg_processor.stop().is_ok());
+               if !std::thread::panicking() {
+                       bg_processor.stop().unwrap();
+               }
        }
 
        #[test]
@@ -1150,6 +1230,35 @@ mod tests {
                }
        }
 
+       #[tokio::test]
+       #[cfg(feature = "futures")]
+       async fn test_channel_manager_persist_error_async() {
+               // Test that if we encounter an error during manager persistence, the thread panics.
+               let nodes = create_nodes(2, "test_persist_error_sync".to_string());
+               open_channel!(nodes[0], nodes[1], 100000);
+
+               let data_dir = nodes[0].persister.get_data_dir();
+               let persister = Arc::new(Persister::new(data_dir).with_manager_error(std::io::ErrorKind::Other, "test"));
+
+               let bp_future = super::process_events_async(
+                       persister, |_: _| {async {}}, nodes[0].chain_monitor.clone(), nodes[0].node.clone(),
+                       nodes[0].rapid_gossip_sync(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(),
+                       Some(nodes[0].scorer.clone()), move |dur: Duration| {
+                               Box::pin(async move {
+                                       tokio::time::sleep(dur).await;
+                                       false // Never exit
+                               })
+                       }, false,
+               );
+               match bp_future.await {
+                       Ok(_) => panic!("Expected error persisting manager"),
+                       Err(e) => {
+                               assert_eq!(e.kind(), std::io::ErrorKind::Other);
+                               assert_eq!(e.get_ref().unwrap().to_string(), "test");
+                       },
+               }
+       }
+
        #[test]
        fn test_network_graph_persist_error() {
                // Test that if we encounter an error during network graph persistence, an error gets returned.
@@ -1194,9 +1303,11 @@ mod tests {
                let persister = Arc::new(Persister::new(data_dir.clone()));
 
                // Set up a background event handler for FundingGenerationReady events.
-               let (sender, receiver) = std::sync::mpsc::sync_channel(1);
+               let (funding_generation_send, funding_generation_recv) = std::sync::mpsc::sync_channel(1);
+               let (channel_pending_send, channel_pending_recv) = std::sync::mpsc::sync_channel(1);
                let event_handler = move |event: Event| match event {
-                       Event::FundingGenerationReady { .. } => sender.send(handle_funding_generation_ready!(event, channel_value)).unwrap(),
+                       Event::FundingGenerationReady { .. } => funding_generation_send.send(handle_funding_generation_ready!(event, channel_value)).unwrap(),
+                       Event::ChannelPending { .. } => channel_pending_send.send(()).unwrap(),
                        Event::ChannelReady { .. } => {},
                        _ => panic!("Unexpected event: {:?}", event),
                };
@@ -1205,10 +1316,15 @@ mod tests {
 
                // Open a channel and check that the FundingGenerationReady event was handled.
                begin_open_channel!(nodes[0], nodes[1], channel_value);
-               let (temporary_channel_id, funding_tx) = receiver
+               let (temporary_channel_id, funding_tx) = funding_generation_recv
                        .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
                        .expect("FundingGenerationReady not handled within deadline");
-               end_open_channel!(nodes[0], nodes[1], temporary_channel_id, funding_tx);
+               nodes[0].node.funding_transaction_generated(&temporary_channel_id, &nodes[1].node.get_our_node_id(), funding_tx.clone()).unwrap();
+               nodes[1].node.handle_funding_created(&nodes[0].node.get_our_node_id(), &get_event_msg!(nodes[0], MessageSendEvent::SendFundingCreated, nodes[1].node.get_our_node_id()));
+               get_event!(nodes[1], Event::ChannelPending);
+               nodes[0].node.handle_funding_signed(&nodes[1].node.get_our_node_id(), &get_event_msg!(nodes[1], MessageSendEvent::SendFundingSigned, nodes[0].node.get_our_node_id()));
+               let _ = channel_pending_recv.recv_timeout(Duration::from_secs(EVENT_DEADLINE))
+                       .expect("ChannelPending not handled within deadline");
 
                // Confirm the funding transaction.
                confirm_transaction(&mut nodes[0], &funding_tx);
@@ -1220,12 +1336,14 @@ mod tests {
                nodes[1].node.handle_channel_ready(&nodes[0].node.get_our_node_id(), &as_funding);
                let _bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
 
-               assert!(bg_processor.stop().is_ok());
+               if !std::thread::panicking() {
+                       bg_processor.stop().unwrap();
+               }
 
                // Set up a background event handler for SpendableOutputs events.
                let (sender, receiver) = std::sync::mpsc::sync_channel(1);
                let event_handler = move |event: Event| match event {
-                       Event::SpendableOutputs { .. } => sender.send(event.clone()).unwrap(),
+                       Event::SpendableOutputs { .. } => sender.send(event).unwrap(),
                        Event::ChannelReady { .. } => {},
                        Event::ChannelClosed { .. } => {},
                        _ => panic!("Unexpected event: {:?}", event),
@@ -1246,7 +1364,9 @@ mod tests {
                        _ => panic!("Unexpected event: {:?}", event),
                }
 
-               assert!(bg_processor.stop().is_ok());
+               if !std::thread::panicking() {
+                       bg_processor.stop().unwrap();
+               }
        }
 
        #[test]
@@ -1265,73 +1385,213 @@ mod tests {
                        }
                }
 
-               assert!(bg_processor.stop().is_ok());
+               if !std::thread::panicking() {
+                       bg_processor.stop().unwrap();
+               }
+       }
+
+       macro_rules! do_test_not_pruning_network_graph_until_graph_sync_completion {
+               ($nodes: expr, $receive: expr, $sleep: expr) => {
+                       let features = ChannelFeatures::empty();
+                       $nodes[0].network_graph.add_channel_from_partial_announcement(
+                               42, 53, features, $nodes[0].node.get_our_node_id(), $nodes[1].node.get_our_node_id()
+                       ).expect("Failed to update channel from partial announcement");
+                       let original_graph_description = $nodes[0].network_graph.to_string();
+                       assert!(original_graph_description.contains("42: features: 0000, node_one:"));
+                       assert_eq!($nodes[0].network_graph.read_only().channels().len(), 1);
+
+                       loop {
+                               $sleep;
+                               let log_entries = $nodes[0].logger.lines.lock().unwrap();
+                               let loop_counter = "Calling ChannelManager's timer_tick_occurred".to_string();
+                               if *log_entries.get(&("lightning_background_processor".to_string(), loop_counter))
+                                       .unwrap_or(&0) > 1
+                               {
+                                       // Wait until the loop has gone around at least twice.
+                                       break
+                               }
+                       }
+
+                       let initialization_input = vec![
+                               76, 68, 75, 1, 111, 226, 140, 10, 182, 241, 179, 114, 193, 166, 162, 70, 174, 99, 247,
+                               79, 147, 30, 131, 101, 225, 90, 8, 156, 104, 214, 25, 0, 0, 0, 0, 0, 97, 227, 98, 218,
+                               0, 0, 0, 4, 2, 22, 7, 207, 206, 25, 164, 197, 231, 230, 231, 56, 102, 61, 250, 251,
+                               187, 172, 38, 46, 79, 247, 108, 44, 155, 48, 219, 238, 252, 53, 192, 6, 67, 2, 36, 125,
+                               157, 176, 223, 175, 234, 116, 94, 248, 201, 225, 97, 235, 50, 47, 115, 172, 63, 136,
+                               88, 216, 115, 11, 111, 217, 114, 84, 116, 124, 231, 107, 2, 158, 1, 242, 121, 152, 106,
+                               204, 131, 186, 35, 93, 70, 216, 10, 237, 224, 183, 89, 95, 65, 3, 83, 185, 58, 138,
+                               181, 64, 187, 103, 127, 68, 50, 2, 201, 19, 17, 138, 136, 149, 185, 226, 156, 137, 175,
+                               110, 32, 237, 0, 217, 90, 31, 100, 228, 149, 46, 219, 175, 168, 77, 4, 143, 38, 128,
+                               76, 97, 0, 0, 0, 2, 0, 0, 255, 8, 153, 192, 0, 2, 27, 0, 0, 0, 1, 0, 0, 255, 2, 68,
+                               226, 0, 6, 11, 0, 1, 2, 3, 0, 0, 0, 2, 0, 40, 0, 0, 0, 0, 0, 0, 3, 232, 0, 0, 3, 232,
+                               0, 0, 0, 1, 0, 0, 0, 0, 58, 85, 116, 216, 255, 8, 153, 192, 0, 2, 27, 0, 0, 25, 0, 0,
+                               0, 1, 0, 0, 0, 125, 255, 2, 68, 226, 0, 6, 11, 0, 1, 5, 0, 0, 0, 0, 29, 129, 25, 192,
+                       ];
+                       $nodes[0].rapid_gossip_sync.update_network_graph_no_std(&initialization_input[..], Some(1642291930)).unwrap();
+
+                       // this should have added two channels
+                       assert_eq!($nodes[0].network_graph.read_only().channels().len(), 3);
+
+                       $receive.expect("Network graph not pruned within deadline");
+
+                       // all channels should now be pruned
+                       assert_eq!($nodes[0].network_graph.read_only().channels().len(), 0);
+               }
        }
 
        #[test]
        fn test_not_pruning_network_graph_until_graph_sync_completion() {
+               let (sender, receiver) = std::sync::mpsc::sync_channel(1);
+
                let nodes = create_nodes(2, "test_not_pruning_network_graph_until_graph_sync_completion".to_string());
                let data_dir = nodes[0].persister.get_data_dir();
-               let (sender, receiver) = std::sync::mpsc::sync_channel(1);
-               let persister = Arc::new(Persister::new(data_dir.clone()).with_graph_persistence_notifier(sender));
-               let network_graph = nodes[0].network_graph.clone();
-               let features = ChannelFeatures::empty();
-               network_graph.add_channel_from_partial_announcement(42, 53, features, nodes[0].node.get_our_node_id(), nodes[1].node.get_our_node_id())
-                       .expect("Failed to update channel from partial announcement");
-               let original_graph_description = network_graph.to_string();
-               assert!(original_graph_description.contains("42: features: 0000, node_one:"));
-               assert_eq!(network_graph.read_only().channels().len(), 1);
+               let persister = Arc::new(Persister::new(data_dir).with_graph_persistence_notifier(sender));
 
                let event_handler = |_: _| {};
                let background_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].rapid_gossip_sync(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()));
 
-               loop {
-                       let log_entries = nodes[0].logger.lines.lock().unwrap();
-                       let loop_counter = "Calling ChannelManager's timer_tick_occurred".to_string();
-                       if *log_entries.get(&("lightning_background_processor".to_string(), loop_counter))
-                               .unwrap_or(&0) > 1
-                       {
-                               // Wait until the loop has gone around at least twice.
-                               break
+               do_test_not_pruning_network_graph_until_graph_sync_completion!(nodes,
+                       receiver.recv_timeout(Duration::from_secs(super::FIRST_NETWORK_PRUNE_TIMER * 5)),
+                       std::thread::sleep(Duration::from_millis(1)));
+
+               background_processor.stop().unwrap();
+       }
+
+       #[tokio::test]
+       #[cfg(feature = "futures")]
+       async fn test_not_pruning_network_graph_until_graph_sync_completion_async() {
+               let (sender, receiver) = std::sync::mpsc::sync_channel(1);
+
+               let nodes = create_nodes(2, "test_not_pruning_network_graph_until_graph_sync_completion_async".to_string());
+               let data_dir = nodes[0].persister.get_data_dir();
+               let persister = Arc::new(Persister::new(data_dir).with_graph_persistence_notifier(sender));
+
+               let (exit_sender, exit_receiver) = tokio::sync::watch::channel(());
+               let bp_future = super::process_events_async(
+                       persister, |_: _| {async {}}, nodes[0].chain_monitor.clone(), nodes[0].node.clone(),
+                       nodes[0].rapid_gossip_sync(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(),
+                       Some(nodes[0].scorer.clone()), move |dur: Duration| {
+                               let mut exit_receiver = exit_receiver.clone();
+                               Box::pin(async move {
+                                       tokio::select! {
+                                               _ = tokio::time::sleep(dur) => false,
+                                               _ = exit_receiver.changed() => true,
+                                       }
+                               })
+                       }, false,
+               );
+               // TODO: Drop _local and simply spawn after #2003
+               let local_set = tokio::task::LocalSet::new();
+               local_set.spawn_local(bp_future);
+               local_set.spawn_local(async move {
+                       do_test_not_pruning_network_graph_until_graph_sync_completion!(nodes, {
+                               let mut i = 0;
+                               loop {
+                                       tokio::time::sleep(Duration::from_secs(super::FIRST_NETWORK_PRUNE_TIMER)).await;
+                                       if let Ok(()) = receiver.try_recv() { break Ok::<(), ()>(()); }
+                                       assert!(i < 5);
+                                       i += 1;
+                               }
+                       }, tokio::time::sleep(Duration::from_millis(1)).await);
+                       exit_sender.send(()).unwrap();
+               });
+               local_set.await;
+       }
+
+       macro_rules! do_test_payment_path_scoring {
+               ($nodes: expr, $receive: expr) => {
+                       // Ensure that we update the scorer when relevant events are processed. In this case, we ensure
+                       // that we update the scorer upon a payment path succeeding (note that the channel must be
+                       // public or else we won't score it).
+                       // A background event handler for FundingGenerationReady events must be hooked up to a
+                       // running background processor.
+                       let scored_scid = 4242;
+                       let secp_ctx = Secp256k1::new();
+                       let node_1_privkey = SecretKey::from_slice(&[42; 32]).unwrap();
+                       let node_1_id = PublicKey::from_secret_key(&secp_ctx, &node_1_privkey);
+
+                       let path = vec![RouteHop {
+                               pubkey: node_1_id,
+                               node_features: NodeFeatures::empty(),
+                               short_channel_id: scored_scid,
+                               channel_features: ChannelFeatures::empty(),
+                               fee_msat: 0,
+                               cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA as u32,
+                       }];
+
+                       $nodes[0].scorer.lock().unwrap().expect(TestResult::PaymentFailure { path: path.clone(), short_channel_id: scored_scid });
+                       $nodes[0].node.push_pending_event(Event::PaymentPathFailed {
+                               payment_id: None,
+                               payment_hash: PaymentHash([42; 32]),
+                               payment_failed_permanently: false,
+                               failure: PathFailure::OnPath { network_update: None },
+                               path: path.clone(),
+                               short_channel_id: Some(scored_scid),
+                       });
+                       let event = $receive.expect("PaymentPathFailed not handled within deadline");
+                       match event {
+                               Event::PaymentPathFailed { .. } => {},
+                               _ => panic!("Unexpected event"),
                        }
-               }
 
-               let initialization_input = vec![
-                       76, 68, 75, 1, 111, 226, 140, 10, 182, 241, 179, 114, 193, 166, 162, 70, 174, 99, 247,
-                       79, 147, 30, 131, 101, 225, 90, 8, 156, 104, 214, 25, 0, 0, 0, 0, 0, 97, 227, 98, 218,
-                       0, 0, 0, 4, 2, 22, 7, 207, 206, 25, 164, 197, 231, 230, 231, 56, 102, 61, 250, 251,
-                       187, 172, 38, 46, 79, 247, 108, 44, 155, 48, 219, 238, 252, 53, 192, 6, 67, 2, 36, 125,
-                       157, 176, 223, 175, 234, 116, 94, 248, 201, 225, 97, 235, 50, 47, 115, 172, 63, 136,
-                       88, 216, 115, 11, 111, 217, 114, 84, 116, 124, 231, 107, 2, 158, 1, 242, 121, 152, 106,
-                       204, 131, 186, 35, 93, 70, 216, 10, 237, 224, 183, 89, 95, 65, 3, 83, 185, 58, 138,
-                       181, 64, 187, 103, 127, 68, 50, 2, 201, 19, 17, 138, 136, 149, 185, 226, 156, 137, 175,
-                       110, 32, 237, 0, 217, 90, 31, 100, 228, 149, 46, 219, 175, 168, 77, 4, 143, 38, 128,
-                       76, 97, 0, 0, 0, 2, 0, 0, 255, 8, 153, 192, 0, 2, 27, 0, 0, 0, 1, 0, 0, 255, 2, 68,
-                       226, 0, 6, 11, 0, 1, 2, 3, 0, 0, 0, 2, 0, 40, 0, 0, 0, 0, 0, 0, 3, 232, 0, 0, 3, 232,
-                       0, 0, 0, 1, 0, 0, 0, 0, 58, 85, 116, 216, 255, 8, 153, 192, 0, 2, 27, 0, 0, 25, 0, 0,
-                       0, 1, 0, 0, 0, 125, 255, 2, 68, 226, 0, 6, 11, 0, 1, 5, 0, 0, 0, 0, 29, 129, 25, 192,
-               ];
-               nodes[0].rapid_gossip_sync.update_network_graph_no_std(&initialization_input[..], Some(1642291930)).unwrap();
-
-               // this should have added two channels
-               assert_eq!(network_graph.read_only().channels().len(), 3);
-
-               let _ = receiver
-                       .recv_timeout(Duration::from_secs(super::FIRST_NETWORK_PRUNE_TIMER * 5))
-                       .expect("Network graph not pruned within deadline");
+                       // Ensure we'll score payments that were explicitly failed back by the destination as
+                       // ProbeSuccess.
+                       $nodes[0].scorer.lock().unwrap().expect(TestResult::ProbeSuccess { path: path.clone() });
+                       $nodes[0].node.push_pending_event(Event::PaymentPathFailed {
+                               payment_id: None,
+                               payment_hash: PaymentHash([42; 32]),
+                               payment_failed_permanently: true,
+                               failure: PathFailure::OnPath { network_update: None },
+                               path: path.clone(),
+                               short_channel_id: None,
+                       });
+                       let event = $receive.expect("PaymentPathFailed not handled within deadline");
+                       match event {
+                               Event::PaymentPathFailed { .. } => {},
+                               _ => panic!("Unexpected event"),
+                       }
 
-               background_processor.stop().unwrap();
+                       $nodes[0].scorer.lock().unwrap().expect(TestResult::PaymentSuccess { path: path.clone() });
+                       $nodes[0].node.push_pending_event(Event::PaymentPathSuccessful {
+                               payment_id: PaymentId([42; 32]),
+                               payment_hash: None,
+                               path: path.clone(),
+                       });
+                       let event = $receive.expect("PaymentPathSuccessful not handled within deadline");
+                       match event {
+                               Event::PaymentPathSuccessful { .. } => {},
+                               _ => panic!("Unexpected event"),
+                       }
+
+                       $nodes[0].scorer.lock().unwrap().expect(TestResult::ProbeSuccess { path: path.clone() });
+                       $nodes[0].node.push_pending_event(Event::ProbeSuccessful {
+                               payment_id: PaymentId([42; 32]),
+                               payment_hash: PaymentHash([42; 32]),
+                               path: path.clone(),
+                       });
+                       let event = $receive.expect("ProbeSuccessful not handled within deadline");
+                       match event {
+                               Event::ProbeSuccessful  { .. } => {},
+                               _ => panic!("Unexpected event"),
+                       }
 
-               // all channels should now be pruned
-               assert_eq!(network_graph.read_only().channels().len(), 0);
+                       $nodes[0].scorer.lock().unwrap().expect(TestResult::ProbeFailure { path: path.clone() });
+                       $nodes[0].node.push_pending_event(Event::ProbeFailed {
+                               payment_id: PaymentId([42; 32]),
+                               payment_hash: PaymentHash([42; 32]),
+                               path,
+                               short_channel_id: Some(scored_scid),
+                       });
+                       let event = $receive.expect("ProbeFailure not handled within deadline");
+                       match event {
+                               Event::ProbeFailed { .. } => {},
+                               _ => panic!("Unexpected event"),
+                       }
+               }
        }
 
        #[test]
        fn test_payment_path_scoring() {
-               // Ensure that we update the scorer when relevant events are processed. In this case, we ensure
-               // that we update the scorer upon a payment path succeeding (note that the channel must be
-               // public or else we won't score it).
-               // Set up a background event handler for FundingGenerationReady events.
                let (sender, receiver) = std::sync::mpsc::sync_channel(1);
                let event_handler = move |event: Event| match event {
                        Event::PaymentPathFailed { .. } => sender.send(event).unwrap(),
@@ -1343,104 +1603,59 @@ mod tests {
 
                let nodes = create_nodes(1, "test_payment_path_scoring".to_string());
                let data_dir = nodes[0].persister.get_data_dir();
-               let persister = Arc::new(Persister::new(data_dir.clone()));
+               let persister = Arc::new(Persister::new(data_dir));
                let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].no_gossip_sync(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()));
 
-               let scored_scid = 4242;
-               let secp_ctx = Secp256k1::new();
-               let node_1_privkey = SecretKey::from_slice(&[42; 32]).unwrap();
-               let node_1_id = PublicKey::from_secret_key(&secp_ctx, &node_1_privkey);
-
-               let path = vec![RouteHop {
-                       pubkey: node_1_id,
-                       node_features: NodeFeatures::empty(),
-                       short_channel_id: scored_scid,
-                       channel_features: ChannelFeatures::empty(),
-                       fee_msat: 0,
-                       cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA as u32,
-               }];
-
-               nodes[0].scorer.lock().unwrap().expect(TestResult::PaymentFailure { path: path.clone(), short_channel_id: scored_scid });
-               nodes[0].node.push_pending_event(Event::PaymentPathFailed {
-                       payment_id: None,
-                       payment_hash: PaymentHash([42; 32]),
-                       payment_failed_permanently: false,
-                       failure: PathFailure::OnPath { network_update: None },
-                       path: path.clone(),
-                       short_channel_id: Some(scored_scid),
-                       retry: None,
-               });
-               let event = receiver
-                       .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
-                       .expect("PaymentPathFailed not handled within deadline");
-               match event {
-                       Event::PaymentPathFailed { .. } => {},
-                       _ => panic!("Unexpected event"),
-               }
+               do_test_payment_path_scoring!(nodes, receiver.recv_timeout(Duration::from_secs(EVENT_DEADLINE)));
 
-               // Ensure we'll score payments that were explicitly failed back by the destination as
-               // ProbeSuccess.
-               nodes[0].scorer.lock().unwrap().expect(TestResult::ProbeSuccess { path: path.clone() });
-               nodes[0].node.push_pending_event(Event::PaymentPathFailed {
-                       payment_id: None,
-                       payment_hash: PaymentHash([42; 32]),
-                       payment_failed_permanently: true,
-                       failure: PathFailure::OnPath { network_update: None },
-                       path: path.clone(),
-                       short_channel_id: None,
-                       retry: None,
-               });
-               let event = receiver
-                       .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
-                       .expect("PaymentPathFailed not handled within deadline");
-               match event {
-                       Event::PaymentPathFailed { .. } => {},
-                       _ => panic!("Unexpected event"),
+               if !std::thread::panicking() {
+                       bg_processor.stop().unwrap();
                }
+       }
 
-               nodes[0].scorer.lock().unwrap().expect(TestResult::PaymentSuccess { path: path.clone() });
-               nodes[0].node.push_pending_event(Event::PaymentPathSuccessful {
-                       payment_id: PaymentId([42; 32]),
-                       payment_hash: None,
-                       path: path.clone(),
-               });
-               let event = receiver
-                       .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
-                       .expect("PaymentPathSuccessful not handled within deadline");
-               match event {
-                       Event::PaymentPathSuccessful { .. } => {},
-                       _ => panic!("Unexpected event"),
-               }
+       #[tokio::test]
+       #[cfg(feature = "futures")]
+       async fn test_payment_path_scoring_async() {
+               let (sender, mut receiver) = tokio::sync::mpsc::channel(1);
+               let event_handler = move |event: Event| {
+                       let sender_ref = sender.clone();
+                       async move {
+                               match event {
+                                       Event::PaymentPathFailed { .. } => { sender_ref.send(event).await.unwrap() },
+                                       Event::PaymentPathSuccessful { .. } => { sender_ref.send(event).await.unwrap() },
+                                       Event::ProbeSuccessful { .. } => { sender_ref.send(event).await.unwrap() },
+                                       Event::ProbeFailed { .. } => { sender_ref.send(event).await.unwrap() },
+                                       _ => panic!("Unexpected event: {:?}", event),
+                               }
+                       }
+               };
 
-               nodes[0].scorer.lock().unwrap().expect(TestResult::ProbeSuccess { path: path.clone() });
-               nodes[0].node.push_pending_event(Event::ProbeSuccessful {
-                       payment_id: PaymentId([42; 32]),
-                       payment_hash: PaymentHash([42; 32]),
-                       path: path.clone(),
-               });
-               let event = receiver
-                       .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
-                       .expect("ProbeSuccessful not handled within deadline");
-               match event {
-                       Event::ProbeSuccessful  { .. } => {},
-                       _ => panic!("Unexpected event"),
-               }
+               let nodes = create_nodes(1, "test_payment_path_scoring_async".to_string());
+               let data_dir = nodes[0].persister.get_data_dir();
+               let persister = Arc::new(Persister::new(data_dir));
 
-               nodes[0].scorer.lock().unwrap().expect(TestResult::ProbeFailure { path: path.clone() });
-               nodes[0].node.push_pending_event(Event::ProbeFailed {
-                       payment_id: PaymentId([42; 32]),
-                       payment_hash: PaymentHash([42; 32]),
-                       path: path.clone(),
-                       short_channel_id: Some(scored_scid),
+               let (exit_sender, exit_receiver) = tokio::sync::watch::channel(());
+
+               let bp_future = super::process_events_async(
+                       persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(),
+                       nodes[0].no_gossip_sync(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(),
+                       Some(nodes[0].scorer.clone()), move |dur: Duration| {
+                               let mut exit_receiver = exit_receiver.clone();
+                               Box::pin(async move {
+                                       tokio::select! {
+                                               _ = tokio::time::sleep(dur) => false,
+                                               _ = exit_receiver.changed() => true,
+                                       }
+                               })
+                       }, false,
+               );
+               // TODO: Drop _local and simply spawn after #2003
+               let local_set = tokio::task::LocalSet::new();
+               local_set.spawn_local(bp_future);
+               local_set.spawn_local(async move {
+                       do_test_payment_path_scoring!(nodes, receiver.recv().await);
+                       exit_sender.send(()).unwrap();
                });
-               let event = receiver
-                       .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
-                       .expect("ProbeFailure not handled within deadline");
-               match event {
-                       Event::ProbeFailed { .. } => {},
-                       _ => panic!("Unexpected event"),
-               }
-
-               assert!(bg_processor.stop().is_ok());
+               local_set.await;
        }
 }