Add a background processing function that is async.
[rust-lightning] / lightning-background-processor / src / lib.rs
index 9783f9e7ebc2a5d31b3f4d76220eea104a9a7125..d38c30e584fa1237b0b3870dda8c7825d0d67e72 100644 (file)
@@ -18,7 +18,7 @@ use lightning::chain::keysinterface::{Sign, KeysInterface};
 use lightning::ln::channelmanager::ChannelManager;
 use lightning::ln::msgs::{ChannelMessageHandler, RoutingMessageHandler};
 use lightning::ln::peer_handler::{CustomMessageHandler, PeerManager, SocketDescriptor};
-use lightning::routing::network_graph::{NetworkGraph, P2PGossipSync};
+use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
 use lightning::routing::scoring::WriteableScore;
 use lightning::util::events::{Event, EventHandler, EventsProvider};
 use lightning::util::logger::Logger;
@@ -31,6 +31,9 @@ use std::thread::JoinHandle;
 use std::time::{Duration, Instant};
 use std::ops::Deref;
 
+#[cfg(feature = "futures")]
+use futures::{select, future::FutureExt};
+
 /// `BackgroundProcessor` takes care of tasks that (1) need to happen periodically to keep
 /// Rust-Lightning running properly, and (2) either can or should be run in the background. Its
 /// responsibilities are:
@@ -40,8 +43,8 @@ use std::ops::Deref;
 ///   [`ChannelManager`] persistence should be done in the background.
 /// * Calling [`ChannelManager::timer_tick_occurred`] and [`PeerManager::timer_tick_occurred`]
 ///   at the appropriate intervals.
-/// * Calling [`NetworkGraph::remove_stale_channels`] (if a [`P2PGossipSync`] is provided to
-///   [`BackgroundProcessor::start`]).
+/// * Calling [`NetworkGraph::remove_stale_channels`] (if a [`GossipSync`] with a [`NetworkGraph`]
+///   is provided to [`BackgroundProcessor::start`]).
 ///
 /// It will also call [`PeerManager::process_events`] periodically though this shouldn't be relied
 /// upon as doing so may result in high latency.
@@ -79,7 +82,7 @@ const PING_TIMER: u64 = 1;
 /// Prune the network graph of stale entries hourly.
 const NETWORK_PRUNE_TIMER: u64 = 60 * 60;
 
-#[cfg(all(not(test), debug_assertions))]
+#[cfg(not(test))]
 const SCORER_PERSIST_TIMER: u64 = 30;
 #[cfg(test)]
 const SCORER_PERSIST_TIMER: u64 = 1;
@@ -89,36 +92,333 @@ const FIRST_NETWORK_PRUNE_TIMER: u64 = 60;
 #[cfg(test)]
 const FIRST_NETWORK_PRUNE_TIMER: u64 = 1;
 
+/// Either [`P2PGossipSync`] or [`RapidGossipSync`].
+pub enum GossipSync<
+       P: Deref<Target = P2PGossipSync<G, A, L>>,
+       R: Deref<Target = RapidGossipSync<G, L>>,
+       G: Deref<Target = NetworkGraph<L>>,
+       A: Deref,
+       L: Deref,
+>
+where A::Target: chain::Access, L::Target: Logger {
+       /// Gossip sync via the lightning peer-to-peer network as defined by BOLT 7.
+       P2P(P),
+       /// Rapid gossip sync from a trusted server.
+       Rapid(R),
+       /// No gossip sync.
+       None,
+}
+
+impl<
+       P: Deref<Target = P2PGossipSync<G, A, L>>,
+       R: Deref<Target = RapidGossipSync<G, L>>,
+       G: Deref<Target = NetworkGraph<L>>,
+       A: Deref,
+       L: Deref,
+> GossipSync<P, R, G, A, L>
+where A::Target: chain::Access, L::Target: Logger {
+       fn network_graph(&self) -> Option<&G> {
+               match self {
+                       GossipSync::P2P(gossip_sync) => Some(gossip_sync.network_graph()),
+                       GossipSync::Rapid(gossip_sync) => Some(gossip_sync.network_graph()),
+                       GossipSync::None => None,
+               }
+       }
+
+       fn prunable_network_graph(&self) -> Option<&G> {
+               match self {
+                       GossipSync::P2P(gossip_sync) => Some(gossip_sync.network_graph()),
+                       GossipSync::Rapid(gossip_sync) => {
+                               if gossip_sync.is_initial_sync_complete() {
+                                       Some(gossip_sync.network_graph())
+                               } else {
+                                       None
+                               }
+                       },
+                       GossipSync::None => None,
+               }
+       }
+}
+
+/// (C-not exported) as the bindings concretize everything and have constructors for us
+impl<P: Deref<Target = P2PGossipSync<G, A, L>>, G: Deref<Target = NetworkGraph<L>>, A: Deref, L: Deref>
+       GossipSync<P, &RapidGossipSync<G, L>, G, A, L>
+where
+       A::Target: chain::Access,
+       L::Target: Logger,
+{
+       /// Initializes a new [`GossipSync::P2P`] variant.
+       pub fn p2p(gossip_sync: P) -> Self {
+               GossipSync::P2P(gossip_sync)
+       }
+}
+
+/// (C-not exported) 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 chain::Access + Send + Sync), L>,
+               R,
+               G,
+               &'a (dyn chain::Access + Send + Sync),
+               L,
+       >
+where
+       L::Target: Logger,
+{
+       /// Initializes a new [`GossipSync::Rapid`] variant.
+       pub fn rapid(gossip_sync: R) -> Self {
+               GossipSync::Rapid(gossip_sync)
+       }
+}
+
+/// (C-not exported) as the bindings concretize everything and have constructors for us
+impl<'a, L: Deref>
+       GossipSync<
+               &P2PGossipSync<&'a NetworkGraph<L>, &'a (dyn chain::Access + Send + Sync), L>,
+               &RapidGossipSync<&'a NetworkGraph<L>, L>,
+               &'a NetworkGraph<L>,
+               &'a (dyn chain::Access + Send + Sync),
+               L,
+       >
+where
+       L::Target: Logger,
+{
+       /// Initializes a new [`GossipSync::None`] variant.
+       pub fn none() -> Self {
+               GossipSync::None
+       }
+}
 
 /// Decorates an [`EventHandler`] with common functionality provided by standard [`EventHandler`]s.
 struct DecoratingEventHandler<
+       'a,
        E: EventHandler,
-       P: Deref<Target = P2PGossipSync<G, A, L>>,
-       G: Deref<Target = NetworkGraph>,
+       PGS: Deref<Target = P2PGossipSync<G, A, L>>,
+       RGS: Deref<Target = RapidGossipSync<G, L>>,
+       G: Deref<Target = NetworkGraph<L>>,
        A: Deref,
        L: Deref,
 >
 where A::Target: chain::Access, L::Target: Logger {
        event_handler: E,
-       p2p_gossip_sync: Option<P>,
+       gossip_sync: &'a GossipSync<PGS, RGS, G, A, L>,
 }
 
 impl<
+       'a,
        E: EventHandler,
-       P: Deref<Target = P2PGossipSync<G, A, L>>,
-       G: Deref<Target = NetworkGraph>,
+       PGS: Deref<Target = P2PGossipSync<G, A, L>>,
+       RGS: Deref<Target = RapidGossipSync<G, L>>,
+       G: Deref<Target = NetworkGraph<L>>,
        A: Deref,
        L: Deref,
-> EventHandler for DecoratingEventHandler<E, P, G, A, L>
+> EventHandler for DecoratingEventHandler<'a, E, PGS, RGS, G, A, L>
 where A::Target: chain::Access, L::Target: Logger {
        fn handle_event(&self, event: &Event) {
-               if let Some(event_handler) = &self.p2p_gossip_sync {
-                       event_handler.handle_event(event);
+               if let Some(network_graph) = self.gossip_sync.network_graph() {
+                       network_graph.handle_event(event);
                }
                self.event_handler.handle_event(event);
        }
 }
 
+macro_rules! define_run_body {
+       ($persister: ident, $event_handler: ident, $chain_monitor: ident, $channel_manager: ident,
+        $gossip_sync: ident, $peer_manager: ident, $logger: ident, $scorer: ident,
+        $loop_exit_check: expr, $await: expr)
+       => { {
+               let event_handler = DecoratingEventHandler {
+                       event_handler: $event_handler,
+                       gossip_sync: &$gossip_sync,
+               };
+
+               log_trace!($logger, "Calling ChannelManager's timer_tick_occurred on startup");
+               $channel_manager.timer_tick_occurred();
+
+               let mut last_freshness_call = Instant::now();
+               let mut last_ping_call = Instant::now();
+               let mut last_prune_call = Instant::now();
+               let mut last_scorer_persist_call = Instant::now();
+               let mut have_pruned = false;
+
+               loop {
+                       $channel_manager.process_pending_events(&event_handler);
+                       $chain_monitor.process_pending_events(&event_handler);
+
+                       // Note that the PeerManager::process_events may block on ChannelManager's locks,
+                       // hence it comes last here. When the ChannelManager finishes whatever it's doing,
+                       // we want to ensure we get into `persist_manager` as quickly as we can, especially
+                       // without running the normal event processing above and handing events to users.
+                       //
+                       // Specifically, on an *extremely* slow machine, we may see ChannelManager start
+                       // processing a message effectively at any point during this loop. In order to
+                       // minimize the time between such processing completing and persisting the updated
+                       // ChannelManager, we want to minimize methods blocking on a ChannelManager
+                       // generally, and as a fallback place such blocking only immediately before
+                       // persistence.
+                       $peer_manager.process_events();
+
+                       // We wait up to 100ms, but track how long it takes to detect being put to sleep,
+                       // see `await_start`'s use below.
+                       let await_start = Instant::now();
+                       let updates_available = $await;
+                       let await_time = await_start.elapsed();
+
+                       if updates_available {
+                               log_trace!($logger, "Persisting ChannelManager...");
+                               $persister.persist_manager(&*$channel_manager)?;
+                               log_trace!($logger, "Done persisting ChannelManager.");
+                       }
+                       // Exit the loop if the background processor was requested to stop.
+                       if $loop_exit_check {
+                               log_trace!($logger, "Terminating background processor.");
+                               break;
+                       }
+                       if last_freshness_call.elapsed().as_secs() > FRESHNESS_TIMER {
+                               log_trace!($logger, "Calling ChannelManager's timer_tick_occurred");
+                               $channel_manager.timer_tick_occurred();
+                               last_freshness_call = Instant::now();
+                       }
+                       if await_time > Duration::from_secs(1) {
+                               // On various platforms, we may be starved of CPU cycles for several reasons.
+                               // E.g. on iOS, if we've been in the background, we will be entirely paused.
+                               // Similarly, if we're on a desktop platform and the device has been asleep, we
+                               // may not get any cycles.
+                               // We detect this by checking if our max-100ms-sleep, above, ran longer than a
+                               // full second, at which point we assume sockets may have been killed (they
+                               // appear to be at least on some platforms, even if it has only been a second).
+                               // Note that we have to take care to not get here just because user event
+                               // processing was slow at the top of the loop. For example, the sample client
+                               // may call Bitcoin Core RPCs during event handling, which very often takes
+                               // more than a handful of seconds to complete, and shouldn't disconnect all our
+                               // peers.
+                               log_trace!($logger, "100ms sleep took more than a second, disconnecting peers.");
+                               $peer_manager.disconnect_all_peers();
+                               last_ping_call = Instant::now();
+                       } else if last_ping_call.elapsed().as_secs() > PING_TIMER {
+                               log_trace!($logger, "Calling PeerManager's timer_tick_occurred");
+                               $peer_manager.timer_tick_occurred();
+                               last_ping_call = Instant::now();
+                       }
+
+                       // Note that we want to run a graph prune once not long after startup before
+                       // falling back to our usual hourly prunes. This avoids short-lived clients never
+                       // pruning their network graph. We run once 60 seconds after startup before
+                       // continuing our normal cadence.
+                       if last_prune_call.elapsed().as_secs() > if have_pruned { NETWORK_PRUNE_TIMER } else { FIRST_NETWORK_PRUNE_TIMER } {
+                               // The network graph must not be pruned while rapid sync completion is pending
+                               log_trace!($logger, "Assessing prunability of network graph");
+                               if let Some(network_graph) = $gossip_sync.prunable_network_graph() {
+                                       network_graph.remove_stale_channels();
+
+                                       if let Err(e) = $persister.persist_graph(network_graph) {
+                                               log_error!($logger, "Error: Failed to persist network graph, check your disk and permissions {}", e)
+                                       }
+
+                                       last_prune_call = Instant::now();
+                                       have_pruned = true;
+                               } else {
+                                       log_trace!($logger, "Not pruning network graph, either due to pending rapid gossip sync or absence of a prunable graph.");
+                               }
+                       }
+
+                       if last_scorer_persist_call.elapsed().as_secs() > SCORER_PERSIST_TIMER {
+                               if let Some(ref scorer) = $scorer {
+                                       log_trace!($logger, "Persisting scorer");
+                                       if let Err(e) = $persister.persist_scorer(&scorer) {
+                                               log_error!($logger, "Error: Failed to persist scorer, check your disk and permissions {}", e)
+                                       }
+                               }
+                               last_scorer_persist_call = Instant::now();
+                       }
+               }
+
+               // After we exit, ensure we persist the ChannelManager one final time - this avoids
+               // some races where users quit while channel updates were in-flight, with
+               // ChannelMonitor update(s) persisted without a corresponding ChannelManager update.
+               $persister.persist_manager(&*$channel_manager)?;
+
+               // Persist Scorer on exit
+               if let Some(ref scorer) = $scorer {
+                       $persister.persist_scorer(&scorer)?;
+               }
+
+               // Persist NetworkGraph on exit
+               if let Some(network_graph) = $gossip_sync.network_graph() {
+                       $persister.persist_graph(network_graph)?;
+               }
+
+               Ok(())
+       } }
+}
+
+/// Processes background events in a future.
+///
+/// `sleeper` should return a future which completes in the given amount of time and returns a
+/// boolean indicating whether the background processing should continue. Once `sleeper` returns a
+/// future which outputs false, the loop will exit and this function's future will complete.
+///
+/// See [`BackgroundProcessor::start`] for information on which actions this handles.
+#[cfg(feature = "futures")]
+pub async fn process_events_async<
+       'a,
+       Signer: 'static + Sign,
+       CA: 'static + Deref + Send + Sync,
+       CF: 'static + Deref + Send + Sync,
+       CW: 'static + Deref + Send + Sync,
+       T: 'static + Deref + Send + Sync,
+       K: 'static + Deref + Send + Sync,
+       F: 'static + Deref + Send + Sync,
+       G: 'static + Deref<Target = NetworkGraph<L>> + Send + Sync,
+       L: 'static + Deref + Send + Sync,
+       P: 'static + Deref + Send + Sync,
+       Descriptor: 'static + SocketDescriptor + Send + Sync,
+       CMH: 'static + Deref + Send + Sync,
+       RMH: 'static + Deref + Send + Sync,
+       EH: 'static + EventHandler + Send,
+       PS: 'static + Deref + Send,
+       M: 'static + Deref<Target = ChainMonitor<Signer, CF, T, F, L, P>> + Send + Sync,
+       CM: 'static + Deref<Target = ChannelManager<Signer, CW, T, K, F, L>> + Send + Sync,
+       PGS: 'static + Deref<Target = P2PGossipSync<G, CA, L>> + Send + Sync,
+       RGS: 'static + Deref<Target = RapidGossipSync<G, L>> + Send,
+       UMH: 'static + Deref + Send + Sync,
+       PM: 'static + Deref<Target = PeerManager<Descriptor, CMH, RMH, L, UMH>> + Send + Sync,
+       S: 'static + Deref<Target = SC> + Send + Sync,
+       SC: WriteableScore<'a>,
+       SleepFuture: core::future::Future<Output = bool>,
+       Sleeper: Fn(Duration) -> SleepFuture
+>(
+       persister: PS, event_handler: EH, chain_monitor: M, channel_manager: CM,
+       gossip_sync: GossipSync<PGS, RGS, G, CA, L>, peer_manager: PM, logger: L, scorer: Option<S>,
+       sleeper: Sleeper,
+) -> Result<(), std::io::Error>
+where
+       CA::Target: 'static + chain::Access,
+       CF::Target: 'static + chain::Filter,
+       CW::Target: 'static + chain::Watch<Signer>,
+       T::Target: 'static + BroadcasterInterface,
+       K::Target: 'static + KeysInterface<Signer = Signer>,
+       F::Target: 'static + FeeEstimator,
+       L::Target: 'static + Logger,
+       P::Target: 'static + Persist<Signer>,
+       CMH::Target: 'static + ChannelMessageHandler,
+       RMH::Target: 'static + RoutingMessageHandler,
+       UMH::Target: 'static + CustomMessageHandler,
+       PS::Target: 'static + Persister<'a, Signer, CW, T, K, F, L, SC>,
+{
+       let mut should_continue = true;
+       define_run_body!(persister, event_handler, chain_monitor, channel_manager,
+               gossip_sync, peer_manager, logger, scorer, should_continue, {
+                       select! {
+                               _ = channel_manager.get_persistable_update_future().fuse() => true,
+                               cont = sleeper(Duration::from_millis(100)).fuse() => {
+                                       should_continue = cont;
+                                       false
+                               }
+                       }
+               })
+}
+
 impl BackgroundProcessor {
        /// Start a background thread that takes care of responsibilities enumerated in the [top-level
        /// documentation].
@@ -134,9 +434,9 @@ impl BackgroundProcessor {
        /// [`ChannelManager`]. See the `lightning-persister` crate for LDK's
        /// provided implementation.
        ///
-       /// [`Persister::persist_graph`] is responsible for writing out the [`NetworkGraph`] to disk. See
-       /// [`NetworkGraph::write`] for writing out a [`NetworkGraph`]. See the `lightning-persister` crate
-       /// for LDK's provided implementation.
+       /// [`Persister::persist_graph`] is responsible for writing out the [`NetworkGraph`] to disk, if
+       /// [`GossipSync`] is supplied. See [`NetworkGraph::write`] for writing out a [`NetworkGraph`].
+       /// See the `lightning-persister` crate for LDK's provided implementation.
        ///
        /// Typically, users should either implement [`Persister::persist_manager`] to never return an
        /// error or call [`join`] and handle any error that may arise. For the latter case,
@@ -151,9 +451,9 @@ impl BackgroundProcessor {
        ///
        /// # Rapid Gossip Sync
        ///
-       /// If rapid gossip sync is meant to run at startup, pass an optional [`RapidGossipSync`]
-       /// to `rapid_gossip_sync` to indicate to [`BackgroundProcessor`] not to prune the
-       /// [`NetworkGraph`] instance until the [`RapidGossipSync`] instance completes its first sync.
+       /// If rapid gossip sync is meant to run at startup, pass [`RapidGossipSync`] via `gossip_sync`
+       /// to indicate that the [`BackgroundProcessor`] should not prune the [`NetworkGraph`] instance
+       /// until the [`RapidGossipSync`] instance completes its first sync.
        ///
        /// [top-level documentation]: BackgroundProcessor
        /// [`join`]: Self::join
@@ -162,8 +462,8 @@ impl BackgroundProcessor {
        /// [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
        /// [`Persister::persist_manager`]: lightning::util::persist::Persister::persist_manager
        /// [`Persister::persist_graph`]: lightning::util::persist::Persister::persist_graph
-       /// [`NetworkGraph`]: lightning::routing::network_graph::NetworkGraph
-       /// [`NetworkGraph::write`]: lightning::routing::network_graph::NetworkGraph#impl-Writeable
+       /// [`NetworkGraph`]: lightning::routing::gossip::NetworkGraph
+       /// [`NetworkGraph::write`]: lightning::routing::gossip::NetworkGraph#impl-Writeable
        pub fn start<
                'a,
                Signer: 'static + Sign,
@@ -173,7 +473,7 @@ impl BackgroundProcessor {
                T: 'static + Deref + Send + Sync,
                K: 'static + Deref + Send + Sync,
                F: 'static + Deref + Send + Sync,
-               G: 'static + Deref<Target = NetworkGraph> + Send + Sync,
+               G: 'static + Deref<Target = NetworkGraph<L>> + Send + Sync,
                L: 'static + Deref + Send + Sync,
                P: 'static + Deref + Send + Sync,
                Descriptor: 'static + SocketDescriptor + Send + Sync,
@@ -184,15 +484,14 @@ impl BackgroundProcessor {
                M: 'static + Deref<Target = ChainMonitor<Signer, CF, T, F, L, P>> + Send + Sync,
                CM: 'static + Deref<Target = ChannelManager<Signer, CW, T, K, F, L>> + Send + Sync,
                PGS: 'static + Deref<Target = P2PGossipSync<G, CA, L>> + Send + Sync,
+               RGS: 'static + Deref<Target = RapidGossipSync<G, L>> + Send,
                UMH: 'static + Deref + Send + Sync,
                PM: 'static + Deref<Target = PeerManager<Descriptor, CMH, RMH, L, UMH>> + Send + Sync,
                S: 'static + Deref<Target = SC> + Send + Sync,
                SC: WriteableScore<'a>,
-               RGS: 'static + Deref<Target = RapidGossipSync<G>> + Send
        >(
                persister: PS, event_handler: EH, chain_monitor: M, channel_manager: CM,
-               p2p_gossip_sync: Option<PGS>, peer_manager: PM, logger: L, scorer: Option<S>,
-               rapid_gossip_sync: Option<RGS>
+               gossip_sync: GossipSync<PGS, RGS, G, CA, L>, peer_manager: PM, logger: L, scorer: Option<S>,
        ) -> Self
        where
                CA::Target: 'static + chain::Access,
@@ -211,137 +510,9 @@ impl BackgroundProcessor {
                let stop_thread = Arc::new(AtomicBool::new(false));
                let stop_thread_clone = stop_thread.clone();
                let handle = thread::spawn(move || -> Result<(), std::io::Error> {
-                       let event_handler = DecoratingEventHandler { event_handler, p2p_gossip_sync: p2p_gossip_sync.as_ref().map(|t| t.deref()) };
-
-                       log_trace!(logger, "Calling ChannelManager's timer_tick_occurred on startup");
-                       channel_manager.timer_tick_occurred();
-
-                       let mut last_freshness_call = Instant::now();
-                       let mut last_ping_call = Instant::now();
-                       let mut last_prune_call = Instant::now();
-                       let mut last_scorer_persist_call = Instant::now();
-                       let mut have_pruned = false;
-
-                       loop {
-                               channel_manager.process_pending_events(&event_handler);
-                               chain_monitor.process_pending_events(&event_handler);
-
-                               // Note that the PeerManager::process_events may block on ChannelManager's locks,
-                               // hence it comes last here. When the ChannelManager finishes whatever it's doing,
-                               // we want to ensure we get into `persist_manager` as quickly as we can, especially
-                               // without running the normal event processing above and handing events to users.
-                               //
-                               // Specifically, on an *extremely* slow machine, we may see ChannelManager start
-                               // processing a message effectively at any point during this loop. In order to
-                               // minimize the time between such processing completing and persisting the updated
-                               // ChannelManager, we want to minimize methods blocking on a ChannelManager
-                               // generally, and as a fallback place such blocking only immediately before
-                               // persistence.
-                               peer_manager.process_events();
-
-                               // We wait up to 100ms, but track how long it takes to detect being put to sleep,
-                               // see `await_start`'s use below.
-                               let await_start = Instant::now();
-                               let updates_available =
-                                       channel_manager.await_persistable_update_timeout(Duration::from_millis(100));
-                               let await_time = await_start.elapsed();
-
-                               if updates_available {
-                                       log_trace!(logger, "Persisting ChannelManager...");
-                                       persister.persist_manager(&*channel_manager)?;
-                                       log_trace!(logger, "Done persisting ChannelManager.");
-                               }
-                               // Exit the loop if the background processor was requested to stop.
-                               if stop_thread.load(Ordering::Acquire) == true {
-                                       log_trace!(logger, "Terminating background processor.");
-                                       break;
-                               }
-                               if last_freshness_call.elapsed().as_secs() > FRESHNESS_TIMER {
-                                       log_trace!(logger, "Calling ChannelManager's timer_tick_occurred");
-                                       channel_manager.timer_tick_occurred();
-                                       last_freshness_call = Instant::now();
-                               }
-                               if await_time > Duration::from_secs(1) {
-                                       // On various platforms, we may be starved of CPU cycles for several reasons.
-                                       // E.g. on iOS, if we've been in the background, we will be entirely paused.
-                                       // Similarly, if we're on a desktop platform and the device has been asleep, we
-                                       // may not get any cycles.
-                                       // We detect this by checking if our max-100ms-sleep, above, ran longer than a
-                                       // full second, at which point we assume sockets may have been killed (they
-                                       // appear to be at least on some platforms, even if it has only been a second).
-                                       // Note that we have to take care to not get here just because user event
-                                       // processing was slow at the top of the loop. For example, the sample client
-                                       // may call Bitcoin Core RPCs during event handling, which very often takes
-                                       // more than a handful of seconds to complete, and shouldn't disconnect all our
-                                       // peers.
-                                       log_trace!(logger, "100ms sleep took more than a second, disconnecting peers.");
-                                       peer_manager.disconnect_all_peers();
-                                       last_ping_call = Instant::now();
-                               } else if last_ping_call.elapsed().as_secs() > PING_TIMER {
-                                       log_trace!(logger, "Calling PeerManager's timer_tick_occurred");
-                                       peer_manager.timer_tick_occurred();
-                                       last_ping_call = Instant::now();
-                               }
-
-                               // Note that we want to run a graph prune once not long after startup before
-                               // falling back to our usual hourly prunes. This avoids short-lived clients never
-                               // pruning their network graph. We run once 60 seconds after startup before
-                               // continuing our normal cadence.
-                               if last_prune_call.elapsed().as_secs() > if have_pruned { NETWORK_PRUNE_TIMER } else { FIRST_NETWORK_PRUNE_TIMER } {
-                                       // The network graph must not be pruned while rapid sync completion is pending
-                                       log_trace!(logger, "Assessing prunability of network graph");
-                                       let graph_to_prune = match rapid_gossip_sync.as_ref() {
-                                               Some(rapid_sync) => {
-                                                       if rapid_sync.is_initial_sync_complete() {
-                                                               Some(rapid_sync.network_graph())
-                                                       } else {
-                                                               None
-                                                       }
-                                               },
-                                               None => p2p_gossip_sync.as_ref().map(|sync| sync.network_graph())
-                                       };
-
-                                       if let Some(network_graph_reference) = graph_to_prune {
-                                               network_graph_reference.remove_stale_channels();
-
-                                               if let Err(e) = persister.persist_graph(network_graph_reference) {
-                                                       log_error!(logger, "Error: Failed to persist network graph, check your disk and permissions {}", e)
-                                               }
-
-                                               last_prune_call = Instant::now();
-                                               have_pruned = true;
-                                       } else {
-                                               log_trace!(logger, "Not pruning network graph, either due to pending rapid gossip sync or absence of a prunable graph.");
-                                       }
-                               }
-
-                               if last_scorer_persist_call.elapsed().as_secs() > SCORER_PERSIST_TIMER {
-                                       if let Some(ref scorer) = scorer {
-                                               log_trace!(logger, "Persisting scorer");
-                                               if let Err(e) = persister.persist_scorer(&scorer) {
-                                                       log_error!(logger, "Error: Failed to persist scorer, check your disk and permissions {}", e)
-                                               }
-                                       }
-                                       last_scorer_persist_call = Instant::now();
-                               }
-                       }
-
-                       // After we exit, ensure we persist the ChannelManager one final time - this avoids
-                       // some races where users quit while channel updates were in-flight, with
-                       // ChannelMonitor update(s) persisted without a corresponding ChannelManager update.
-                       persister.persist_manager(&*channel_manager)?;
-
-                       // Persist Scorer on exit
-                       if let Some(ref scorer) = scorer {
-                               persister.persist_scorer(&scorer)?;
-                       }
-
-                       // Persist NetworkGraph on exit
-                       if let Some(ref gossip_sync) = p2p_gossip_sync {
-                               persister.persist_graph(gossip_sync.network_graph())?;
-                       }
-
-                       Ok(())
+                       define_run_body!(persister, event_handler, chain_monitor, channel_manager,
+                               gossip_sync, peer_manager, logger, scorer, stop_thread.load(Ordering::Acquire),
+                               channel_manager.await_persistable_update_timeout(Duration::from_millis(100)))
                });
                Self { stop_thread: stop_thread_clone, thread_handle: Some(handle) }
        }
@@ -408,7 +579,7 @@ mod tests {
        use lightning::ln::features::{ChannelFeatures, InitFeatures};
        use lightning::ln::msgs::{ChannelMessageHandler, Init};
        use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor, IgnoringMessageHandler};
-       use lightning::routing::network_graph::{NetworkGraph, P2PGossipSync};
+       use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
        use lightning::util::config::UserConfig;
        use lightning::util::events::{Event, MessageSendEventsProvider, MessageSendEvent};
        use lightning::util::ser::Writeable;
@@ -424,7 +595,7 @@ mod tests {
        use std::time::Duration;
        use lightning::routing::scoring::{FixedPenaltyScorer};
        use lightning_rapid_gossip_sync::RapidGossipSync;
-       use super::{BackgroundProcessor, FRESHNESS_TIMER};
+       use super::{BackgroundProcessor, GossipSync, FRESHNESS_TIMER};
 
        const EVENT_DEADLINE: u64 = 5 * FRESHNESS_TIMER;
 
@@ -440,18 +611,35 @@ mod tests {
 
        type ChainMonitor = chainmonitor::ChainMonitor<InMemorySigner, Arc<test_utils::TestChainSource>, Arc<test_utils::TestBroadcaster>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>, Arc<FilesystemPersister>>;
 
+       type PGS = Arc<P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>>;
+       type RGS = Arc<RapidGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestLogger>>>;
+
        struct Node {
                node: Arc<SimpleArcChannelManager<ChainMonitor, test_utils::TestBroadcaster, test_utils::TestFeeEstimator, test_utils::TestLogger>>,
-               p2p_gossip_sync: Option<Arc<P2PGossipSync<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>>>,
+               p2p_gossip_sync: PGS,
+               rapid_gossip_sync: RGS,
                peer_manager: Arc<PeerManager<TestDescriptor, Arc<test_utils::TestChannelMessageHandler>, Arc<test_utils::TestRoutingMessageHandler>, Arc<test_utils::TestLogger>, IgnoringMessageHandler>>,
                chain_monitor: Arc<ChainMonitor>,
                persister: Arc<FilesystemPersister>,
                tx_broadcaster: Arc<test_utils::TestBroadcaster>,
-               network_graph: Arc<NetworkGraph>,
+               network_graph: Arc<NetworkGraph<Arc<test_utils::TestLogger>>>,
                logger: Arc<test_utils::TestLogger>,
                best_block: BestBlock,
                scorer: Arc<Mutex<FixedPenaltyScorer>>,
-               rapid_gossip_sync: Option<Arc<RapidGossipSync<Arc<NetworkGraph>>>>
+       }
+
+       impl Node {
+               fn p2p_gossip_sync(&self) -> GossipSync<PGS, RGS, Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>> {
+                       GossipSync::P2P(self.p2p_gossip_sync.clone())
+               }
+
+               fn rapid_gossip_sync(&self) -> GossipSync<PGS, RGS, Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>> {
+                       GossipSync::Rapid(self.rapid_gossip_sync.clone())
+               }
+
+               fn no_gossip_sync(&self) -> GossipSync<PGS, RGS, Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>> {
+                       GossipSync::None
+               }
        }
 
        impl Drop for Node {
@@ -546,13 +734,13 @@ mod tests {
                        let best_block = BestBlock::from_genesis(network);
                        let params = ChainParameters { network, best_block };
                        let manager = Arc::new(ChannelManager::new(fee_estimator.clone(), chain_monitor.clone(), tx_broadcaster.clone(), logger.clone(), keys_manager.clone(), UserConfig::default(), params));
-                       let network_graph = Arc::new(NetworkGraph::new(genesis_block.header.block_hash()));
-                       let p2p_gossip_sync = Some(Arc::new(P2PGossipSync::new(network_graph.clone(), Some(chain_source.clone()), logger.clone())));
+                       let network_graph = Arc::new(NetworkGraph::new(genesis_block.header.block_hash(), logger.clone()));
+                       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 msg_handler = MessageHandler { chan_handler: Arc::new(test_utils::TestChannelMessageHandler::new()), route_handler: Arc::new(test_utils::TestRoutingMessageHandler::new() )};
                        let peer_manager = Arc::new(PeerManager::new(msg_handler, keys_manager.get_node_secret(Recipient::Node).unwrap(), &seed, logger.clone(), IgnoringMessageHandler{}));
                        let scorer = Arc::new(Mutex::new(test_utils::TestScorer::with_penalty(0)));
-                       let rapid_gossip_sync = None;
-                       let node = Node { node: manager, p2p_gossip_sync, peer_manager, chain_monitor, persister, tx_broadcaster, network_graph, logger, best_block, scorer, rapid_gossip_sync };
+                       let node = Node { node: manager, p2p_gossip_sync, rapid_gossip_sync, peer_manager, chain_monitor, persister, tx_broadcaster, network_graph, logger, best_block, scorer };
                        nodes.push(node);
                }
 
@@ -650,7 +838,7 @@ mod tests {
                let data_dir = nodes[0].persister.get_data_dir();
                let persister = Arc::new(Persister::new(data_dir));
                let event_handler = |_: &_| {};
-               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(),  nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), nodes[0].rapid_gossip_sync.clone());
+               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()));
 
                macro_rules! check_persisted_data {
                        ($node: expr, $filepath: expr) => {
@@ -685,7 +873,7 @@ mod tests {
                }
 
                // Force-close the channel.
-               nodes[0].node.force_close_channel(&OutPoint { txid: tx.txid(), index: 0 }.to_channel_id(), &nodes[1].node.get_our_node_id()).unwrap();
+               nodes[0].node.force_close_broadcasting_latest_txn(&OutPoint { txid: tx.txid(), index: 0 }.to_channel_id(), &nodes[1].node.get_our_node_id()).unwrap();
 
                // Check that the force-close updates are persisted.
                check_persisted_data!(nodes[0].node, filepath.clone());
@@ -695,10 +883,7 @@ mod tests {
 
                // Check network graph is persisted
                let filepath = get_full_filepath("test_background_processor_persister_0".to_string(), "network_graph".to_string());
-               if let Some(ref handler) = nodes[0].p2p_gossip_sync {
-                       let network_graph = handler.network_graph();
-                       check_persisted_data!(network_graph, filepath.clone());
-               }
+               check_persisted_data!(nodes[0].network_graph, filepath.clone());
 
                // Check scorer is persisted
                let filepath = get_full_filepath("test_background_processor_persister_0".to_string(), "scorer".to_string());
@@ -715,7 +900,7 @@ mod tests {
                let data_dir = nodes[0].persister.get_data_dir();
                let persister = Arc::new(Persister::new(data_dir));
                let event_handler = |_: &_| {};
-               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), nodes[0].rapid_gossip_sync.clone());
+               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()));
                loop {
                        let log_entries = nodes[0].logger.lines.lock().unwrap();
                        let desired_log = "Calling ChannelManager's timer_tick_occurred".to_string();
@@ -738,7 +923,7 @@ mod tests {
                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 event_handler = |_: &_| {};
-               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), nodes[0].rapid_gossip_sync.clone());
+               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()));
                match bg_processor.join() {
                        Ok(_) => panic!("Expected error persisting manager"),
                        Err(e) => {
@@ -755,7 +940,7 @@ mod tests {
                let data_dir = nodes[0].persister.get_data_dir();
                let persister = Arc::new(Persister::new(data_dir).with_graph_error(std::io::ErrorKind::Other, "test"));
                let event_handler = |_: &_| {};
-               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), nodes[0].rapid_gossip_sync.clone());
+               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()));
 
                match bg_processor.stop() {
                        Ok(_) => panic!("Expected error persisting network graph"),
@@ -773,7 +958,7 @@ mod tests {
                let data_dir = nodes[0].persister.get_data_dir();
                let persister = Arc::new(Persister::new(data_dir).with_scorer_error(std::io::ErrorKind::Other, "test"));
                let event_handler = |_: &_| {};
-               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(),  nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), nodes[0].rapid_gossip_sync.clone());
+               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()));
 
                match bg_processor.stop() {
                        Ok(_) => panic!("Expected error persisting scorer"),
@@ -796,7 +981,7 @@ mod tests {
                let event_handler = move |event: &Event| {
                        sender.send(handle_funding_generation_ready!(event, channel_value)).unwrap();
                };
-               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), nodes[0].rapid_gossip_sync.clone());
+               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()));
 
                // Open a channel and check that the FundingGenerationReady event was handled.
                begin_open_channel!(nodes[0], nodes[1], channel_value);
@@ -821,10 +1006,10 @@ mod tests {
                let (sender, receiver) = std::sync::mpsc::sync_channel(1);
                let event_handler = move |event: &Event| sender.send(event.clone()).unwrap();
                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].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), nodes[0].rapid_gossip_sync.clone());
+               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()));
 
                // Force close the channel and check that the SpendableOutputs event was handled.
-               nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id, &nodes[1].node.get_our_node_id()).unwrap();
+               nodes[0].node.force_close_broadcasting_latest_txn(&nodes[0].node.list_channels()[0].channel_id, &nodes[1].node.get_our_node_id()).unwrap();
                let commitment_tx = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().pop().unwrap();
                confirm_transaction_depth(&mut nodes[0], &commitment_tx, BREAKDOWN_TIMEOUT as u32);
                let event = receiver
@@ -845,7 +1030,7 @@ mod tests {
                let data_dir = nodes[0].persister.get_data_dir();
                let persister = Arc::new(Persister::new(data_dir));
                let event_handler = |_: &_| {};
-               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(),  nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), nodes[0].rapid_gossip_sync.clone());
+               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()));
 
                loop {
                        let log_entries = nodes[0].logger.lines.lock().unwrap();
@@ -865,7 +1050,6 @@ mod tests {
                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 rapid_sync = Arc::new(RapidGossipSync::new(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");
@@ -874,7 +1058,7 @@ mod tests {
                assert_eq!(network_graph.read_only().channels().len(), 1);
 
                let event_handler = |_: &_| {};
-               let background_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), Some(rapid_sync.clone()));
+               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();
@@ -901,7 +1085,7 @@ mod tests {
                        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,
                ];
-               rapid_sync.update_network_graph(&initialization_input[..]).unwrap();
+               nodes[0].rapid_gossip_sync.update_network_graph(&initialization_input[..]).unwrap();
 
                // this should have added two channels
                assert_eq!(network_graph.read_only().channels().len(), 3);
@@ -928,7 +1112,7 @@ mod tests {
                let router = DefaultRouter::new(Arc::clone(&nodes[0].network_graph), Arc::clone(&nodes[0].logger), random_seed_bytes);
                let invoice_payer = Arc::new(InvoicePayer::new(Arc::clone(&nodes[0].node), router, Arc::clone(&nodes[0].scorer), Arc::clone(&nodes[0].logger), |_: &_| {}, Retry::Attempts(2)));
                let event_handler = Arc::clone(&invoice_payer);
-               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].p2p_gossip_sync.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()), nodes[0].rapid_gossip_sync.clone());
+               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()));
                assert!(bg_processor.stop().is_ok());
        }
 }