Merge pull request #2413 from valentinewallace/2023-07-route-blinding
[rust-lightning] / lightning / src / ln / channelmanager.rs
index d0dff57ed3b0c86642264188097a799f5b49cc23..90451d59d66d635821ffbe3ce32790d471290c6c 100644 (file)
@@ -177,7 +177,7 @@ pub(super) enum HTLCForwardInfo {
 }
 
 /// Tracks the inbound corresponding to an outbound HTLC
-#[derive(Clone, Hash, PartialEq, Eq)]
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub(crate) struct HTLCPreviousHopData {
        // Note that this may be an outbound SCID alias for the associated channel.
        short_channel_id: u64,
@@ -233,7 +233,8 @@ impl From<&ClaimableHTLC> for events::ClaimedHTLC {
        }
 }
 
-/// A payment identifier used to uniquely identify a payment to LDK.
+/// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+/// a payment and ensure idempotency in LDK.
 ///
 /// This is not exported to bindings users as we just use [u8; 32] directly
 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
@@ -282,7 +283,7 @@ impl Readable for InterceptId {
        }
 }
 
-#[derive(Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 /// Uniquely describes an HTLC by its source. Just the guaranteed-unique subset of [`HTLCSource`].
 pub(crate) enum SentHTLCId {
        PreviousHopData { short_channel_id: u64, htlc_id: u64 },
@@ -313,7 +314,7 @@ impl_writeable_tlv_based_enum!(SentHTLCId,
 
 /// Tracks the inbound corresponding to an outbound HTLC
 #[allow(clippy::derive_hash_xor_eq)] // Our Hash is faithful to the data, we just don't have SecretKey::hash
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) enum HTLCSource {
        PreviousHopData(HTLCPreviousHopData),
        OutboundRoute {
@@ -494,6 +495,10 @@ impl MsgHandleErrInternal {
                        channel_capacity: None,
                }
        }
+
+       fn closes_channel(&self) -> bool {
+               self.chan_id.is_some()
+       }
 }
 
 /// We hold back HTLCs we intend to relay for a random interval greater than this (see
@@ -655,7 +660,6 @@ pub(crate) enum RAAMonitorUpdateBlockingAction {
 }
 
 impl RAAMonitorUpdateBlockingAction {
-       #[allow(unused)]
        fn from_prev_hop_data(prev_hop: &HTLCPreviousHopData) -> Self {
                Self::ForwardedPaymentInboundClaim {
                        channel_id: prev_hop.outpoint.to_channel_id(),
@@ -1185,7 +1189,8 @@ where
 
        background_events_processed_since_startup: AtomicBool,
 
-       persistence_notifier: Notifier,
+       event_persist_notifier: Notifier,
+       needs_persist_flag: AtomicBool,
 
        entropy_source: ES,
        node_signer: NS,
@@ -1214,7 +1219,8 @@ pub struct ChainParameters {
 #[must_use]
 enum NotifyOption {
        DoPersist,
-       SkipPersist,
+       SkipPersistHandleEvents,
+       SkipPersistNoEvents,
 }
 
 /// Whenever we release the `ChannelManager`'s `total_consistency_lock`, from read mode, it is
@@ -1227,43 +1233,75 @@ enum NotifyOption {
 /// We allow callers to either always notify by constructing with `notify_on_drop` or choose to
 /// notify or not based on whether relevant changes have been made, providing a closure to
 /// `optionally_notify` which returns a `NotifyOption`.
-struct PersistenceNotifierGuard<'a, F: Fn() -> NotifyOption> {
-       persistence_notifier: &'a Notifier,
+struct PersistenceNotifierGuard<'a, F: FnMut() -> NotifyOption> {
+       event_persist_notifier: &'a Notifier,
+       needs_persist_flag: &'a AtomicBool,
        should_persist: F,
        // We hold onto this result so the lock doesn't get released immediately.
        _read_guard: RwLockReadGuard<'a, ()>,
 }
 
 impl<'a> PersistenceNotifierGuard<'a, fn() -> NotifyOption> { // We don't care what the concrete F is here, it's unused
-       fn notify_on_drop<C: AChannelManager>(cm: &'a C) -> PersistenceNotifierGuard<'a, impl Fn() -> NotifyOption> {
+       /// Notifies any waiters and indicates that we need to persist, in addition to possibly having
+       /// events to handle.
+       ///
+       /// This must always be called if the changes included a `ChannelMonitorUpdate`, as well as in
+       /// other cases where losing the changes on restart may result in a force-close or otherwise
+       /// isn't ideal.
+       fn notify_on_drop<C: AChannelManager>(cm: &'a C) -> PersistenceNotifierGuard<'a, impl FnMut() -> NotifyOption> {
+               Self::optionally_notify(cm, || -> NotifyOption { NotifyOption::DoPersist })
+       }
+
+       fn optionally_notify<F: FnMut() -> NotifyOption, C: AChannelManager>(cm: &'a C, mut persist_check: F)
+       -> PersistenceNotifierGuard<'a, impl FnMut() -> NotifyOption> {
                let read_guard = cm.get_cm().total_consistency_lock.read().unwrap();
-               let _ = cm.get_cm().process_background_events(); // We always persist
+               let force_notify = cm.get_cm().process_background_events();
 
                PersistenceNotifierGuard {
-                       persistence_notifier: &cm.get_cm().persistence_notifier,
-                       should_persist: || -> NotifyOption { NotifyOption::DoPersist },
+                       event_persist_notifier: &cm.get_cm().event_persist_notifier,
+                       needs_persist_flag: &cm.get_cm().needs_persist_flag,
+                       should_persist: move || {
+                               // Pick the "most" action between `persist_check` and the background events
+                               // processing and return that.
+                               let notify = persist_check();
+                               match (notify, force_notify) {
+                                       (NotifyOption::DoPersist, _) => NotifyOption::DoPersist,
+                                       (_, NotifyOption::DoPersist) => NotifyOption::DoPersist,
+                                       (NotifyOption::SkipPersistHandleEvents, _) => NotifyOption::SkipPersistHandleEvents,
+                                       (_, NotifyOption::SkipPersistHandleEvents) => NotifyOption::SkipPersistHandleEvents,
+                                       _ => NotifyOption::SkipPersistNoEvents,
+                               }
+                       },
                        _read_guard: read_guard,
                }
-
        }
 
        /// Note that if any [`ChannelMonitorUpdate`]s are possibly generated,
-       /// [`ChannelManager::process_background_events`] MUST be called first.
-       fn optionally_notify<F: Fn() -> NotifyOption>(lock: &'a RwLock<()>, notifier: &'a Notifier, persist_check: F) -> PersistenceNotifierGuard<'a, F> {
-               let read_guard = lock.read().unwrap();
+       /// [`ChannelManager::process_background_events`] MUST be called first (or
+       /// [`Self::optionally_notify`] used).
+       fn optionally_notify_skipping_background_events<F: Fn() -> NotifyOption, C: AChannelManager>
+       (cm: &'a C, persist_check: F) -> PersistenceNotifierGuard<'a, F> {
+               let read_guard = cm.get_cm().total_consistency_lock.read().unwrap();
 
                PersistenceNotifierGuard {
-                       persistence_notifier: notifier,
+                       event_persist_notifier: &cm.get_cm().event_persist_notifier,
+                       needs_persist_flag: &cm.get_cm().needs_persist_flag,
                        should_persist: persist_check,
                        _read_guard: read_guard,
                }
        }
 }
 
-impl<'a, F: Fn() -> NotifyOption> Drop for PersistenceNotifierGuard<'a, F> {
+impl<'a, F: FnMut() -> NotifyOption> Drop for PersistenceNotifierGuard<'a, F> {
        fn drop(&mut self) {
-               if (self.should_persist)() == NotifyOption::DoPersist {
-                       self.persistence_notifier.notify();
+               match (self.should_persist)() {
+                       NotifyOption::DoPersist => {
+                               self.needs_persist_flag.store(true, Ordering::Release);
+                               self.event_persist_notifier.notify()
+                       },
+                       NotifyOption::SkipPersistHandleEvents =>
+                               self.event_persist_notifier.notify(),
+                       NotifyOption::SkipPersistNoEvents => {},
                }
        }
 }
@@ -1669,11 +1707,15 @@ pub enum ChannelShutdownState {
 pub enum RecentPaymentDetails {
        /// When an invoice was requested and thus a payment has not yet been sent.
        AwaitingInvoice {
-               /// Identifier for the payment to ensure idempotency.
+               /// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+               /// a payment and ensure idempotency in LDK.
                payment_id: PaymentId,
        },
        /// When a payment is still being sent and awaiting successful delivery.
        Pending {
+               /// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+               /// a payment and ensure idempotency in LDK.
+               payment_id: PaymentId,
                /// Hash of the payment that is currently being sent but has yet to be fulfilled or
                /// abandoned.
                payment_hash: PaymentHash,
@@ -1685,6 +1727,9 @@ pub enum RecentPaymentDetails {
        /// been resolved. Upon receiving [`Event::PaymentSent`], we delay for a few minutes before the
        /// payment is removed from tracking.
        Fulfilled {
+               /// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+               /// a payment and ensure idempotency in LDK.
+               payment_id: PaymentId,
                /// Hash of the payment that was claimed. `None` for serializations of [`ChannelManager`]
                /// made before LDK version 0.0.104.
                payment_hash: Option<PaymentHash>,
@@ -1693,6 +1738,9 @@ pub enum RecentPaymentDetails {
        /// abandoned via [`ChannelManager::abandon_payment`], it is marked as abandoned until all
        /// pending HTLCs for this payment resolve and an [`Event::PaymentFailed`] is generated.
        Abandoned {
+               /// A user-provided identifier in [`ChannelManager::send_payment`] used to uniquely identify
+               /// a payment and ensure idempotency in LDK.
+               payment_id: PaymentId,
                /// Hash of the payment that we have given up trying to send.
                payment_hash: PaymentHash,
        },
@@ -2075,7 +2123,7 @@ macro_rules! process_events_body {
                                return;
                        }
 
-                       let mut result = NotifyOption::SkipPersist;
+                       let mut result;
 
                        {
                                // We'll acquire our total consistency lock so that we can be sure no other
@@ -2084,7 +2132,7 @@ macro_rules! process_events_body {
 
                                // Because `handle_post_event_actions` may send `ChannelMonitorUpdate`s to the user we must
                                // ensure any startup-generated background events are handled first.
-                               if $self.process_background_events() == NotifyOption::DoPersist { result = NotifyOption::DoPersist; }
+                               result = $self.process_background_events();
 
                                // TODO: This behavior should be documented. It's unintuitive that we query
                                // ChannelMonitors when clearing other events.
@@ -2124,8 +2172,14 @@ macro_rules! process_events_body {
                                processed_all_events = false;
                        }
 
-                       if result == NotifyOption::DoPersist {
-                               $self.persistence_notifier.notify();
+                       match result {
+                               NotifyOption::DoPersist => {
+                                       $self.needs_persist_flag.store(true, Ordering::Release);
+                                       $self.event_persist_notifier.notify();
+                               },
+                               NotifyOption::SkipPersistHandleEvents =>
+                                       $self.event_persist_notifier.notify(),
+                               NotifyOption::SkipPersistNoEvents => {},
                        }
                }
        }
@@ -2204,7 +2258,9 @@ where
                        pending_background_events: Mutex::new(Vec::new()),
                        total_consistency_lock: RwLock::new(()),
                        background_events_processed_since_startup: AtomicBool::new(false),
-                       persistence_notifier: Notifier::new(),
+
+                       event_persist_notifier: Notifier::new(),
+                       needs_persist_flag: AtomicBool::new(false),
 
                        entropy_source,
                        node_signer,
@@ -2429,15 +2485,16 @@ where
                                },
                                PendingOutboundPayment::Retryable { payment_hash, total_msat, .. } => {
                                        Some(RecentPaymentDetails::Pending {
+                                               payment_id: *payment_id,
                                                payment_hash: *payment_hash,
                                                total_msat: *total_msat,
                                        })
                                },
                                PendingOutboundPayment::Abandoned { payment_hash, .. } => {
-                                       Some(RecentPaymentDetails::Abandoned { payment_hash: *payment_hash })
+                                       Some(RecentPaymentDetails::Abandoned { payment_id: *payment_id, payment_hash: *payment_hash })
                                },
                                PendingOutboundPayment::Fulfilled { payment_hash, .. } => {
-                                       Some(RecentPaymentDetails::Fulfilled { payment_hash: *payment_hash })
+                                       Some(RecentPaymentDetails::Fulfilled { payment_id: *payment_id, payment_hash: *payment_hash })
                                },
                                PendingOutboundPayment::Legacy { .. } => None
                        })
@@ -4343,7 +4400,7 @@ where
                let mut background_events = Vec::new();
                mem::swap(&mut *self.pending_background_events.lock().unwrap(), &mut background_events);
                if background_events.is_empty() {
-                       return NotifyOption::SkipPersist;
+                       return NotifyOption::SkipPersistNoEvents;
                }
 
                for event in background_events.drain(..) {
@@ -4412,17 +4469,17 @@ where
        }
 
        fn update_channel_fee(&self, chan_id: &ChannelId, chan: &mut Channel<SP>, new_feerate: u32) -> NotifyOption {
-               if !chan.context.is_outbound() { return NotifyOption::SkipPersist; }
+               if !chan.context.is_outbound() { return NotifyOption::SkipPersistNoEvents; }
                // If the feerate has decreased by less than half, don't bother
                if new_feerate <= chan.context.get_feerate_sat_per_1000_weight() && new_feerate * 2 > chan.context.get_feerate_sat_per_1000_weight() {
                        log_trace!(self.logger, "Channel {} does not qualify for a feerate change from {} to {}.",
-                               &chan_id, chan.context.get_feerate_sat_per_1000_weight(), new_feerate);
-                       return NotifyOption::SkipPersist;
+                               chan_id, chan.context.get_feerate_sat_per_1000_weight(), new_feerate);
+                       return NotifyOption::SkipPersistNoEvents;
                }
                if !chan.context.is_live() {
                        log_trace!(self.logger, "Channel {} does not qualify for a feerate change from {} to {} as it cannot currently be updated (probably the peer is disconnected).",
-                               &chan_id, chan.context.get_feerate_sat_per_1000_weight(), new_feerate);
-                       return NotifyOption::SkipPersist;
+                               chan_id, chan.context.get_feerate_sat_per_1000_weight(), new_feerate);
+                       return NotifyOption::SkipPersistNoEvents;
                }
                log_trace!(self.logger, "Channel {} qualifies for a feerate change from {} to {}.",
                        &chan_id, chan.context.get_feerate_sat_per_1000_weight(), new_feerate);
@@ -4437,8 +4494,8 @@ where
        /// these a fuzz failure (as they usually indicate a channel force-close, which is exactly what
        /// it wants to detect). Thus, we have a variant exposed here for its benefit.
        pub fn maybe_update_chan_fees(&self) {
-               PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
-                       let mut should_persist = self.process_background_events();
+               PersistenceNotifierGuard::optionally_notify(self, || {
+                       let mut should_persist = NotifyOption::SkipPersistNoEvents;
 
                        let normal_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
                        let min_mempool_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::MempoolMinimum);
@@ -4482,8 +4539,8 @@ where
        /// [`ChannelUpdate`]: msgs::ChannelUpdate
        /// [`ChannelConfig`]: crate::util::config::ChannelConfig
        pub fn timer_tick_occurred(&self) {
-               PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
-                       let mut should_persist = self.process_background_events();
+               PersistenceNotifierGuard::optionally_notify(self, || {
+                       let mut should_persist = NotifyOption::SkipPersistNoEvents;
 
                        let normal_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
                        let min_mempool_feerate = self.fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::MempoolMinimum);
@@ -5178,11 +5235,17 @@ where
                self.pending_outbound_payments.finalize_claims(sources, &self.pending_events);
        }
 
-       fn claim_funds_internal(&self, source: HTLCSource, payment_preimage: PaymentPreimage, forwarded_htlc_value_msat: Option<u64>, from_onchain: bool, next_channel_outpoint: OutPoint) {
+       fn claim_funds_internal(&self, source: HTLCSource, payment_preimage: PaymentPreimage,
+               forwarded_htlc_value_msat: Option<u64>, from_onchain: bool,
+               next_channel_counterparty_node_id: Option<PublicKey>, next_channel_outpoint: OutPoint
+       ) {
                match source {
                        HTLCSource::OutboundRoute { session_priv, payment_id, path, .. } => {
                                debug_assert!(self.background_events_processed_since_startup.load(Ordering::Acquire),
                                        "We don't support claim_htlc claims during startup - monitors may not be available yet");
+                               if let Some(pubkey) = next_channel_counterparty_node_id {
+                                       debug_assert_eq!(pubkey, path.hops[0].pubkey);
+                               }
                                let ev_completion_action = EventCompletionAction::ReleaseRAAChannelMonitorUpdate {
                                        channel_funding_outpoint: next_channel_outpoint,
                                        counterparty_node_id: path.hops[0].pubkey,
@@ -5193,6 +5256,7 @@ where
                        },
                        HTLCSource::PreviousHopData(hop_data) => {
                                let prev_outpoint = hop_data.outpoint;
+                               let completed_blocker = RAAMonitorUpdateBlockingAction::from_prev_hop_data(&hop_data);
                                let res = self.claim_funds_from_hop(hop_data, payment_preimage,
                                        |htlc_claim_value_msat| {
                                                if let Some(forwarded_htlc_value) = forwarded_htlc_value_msat {
@@ -5208,7 +5272,17 @@ where
                                                                        next_channel_id: Some(next_channel_outpoint.to_channel_id()),
                                                                        outbound_amount_forwarded_msat: forwarded_htlc_value_msat,
                                                                },
-                                                               downstream_counterparty_and_funding_outpoint: None,
+                                                               downstream_counterparty_and_funding_outpoint:
+                                                                       if let Some(node_id) = next_channel_counterparty_node_id {
+                                                                               Some((node_id, next_channel_outpoint, completed_blocker))
+                                                                       } else {
+                                                                               // We can only get `None` here if we are processing a
+                                                                               // `ChannelMonitor`-originated event, in which case we
+                                                                               // don't care about ensuring we wake the downstream
+                                                                               // channel's monitor updating - the channel is already
+                                                                               // closed.
+                                                                               None
+                                                                       },
                                                        })
                                                } else { None }
                                        });
@@ -5544,6 +5618,8 @@ where
        }
 
        fn internal_open_channel(&self, counterparty_node_id: &PublicKey, msg: &msgs::OpenChannel) -> Result<(), MsgHandleErrInternal> {
+               // Note that the ChannelManager is NOT re-persisted on disk after this, so any changes are
+               // likely to be lost on restart!
                if msg.chain_hash != self.genesis_hash {
                        return Err(MsgHandleErrInternal::send_err_msg_no_close("Unknown genesis block hash".to_owned(), msg.temporary_channel_id.clone()));
                }
@@ -5643,6 +5719,8 @@ where
        }
 
        fn internal_accept_channel(&self, counterparty_node_id: &PublicKey, msg: &msgs::AcceptChannel) -> Result<(), MsgHandleErrInternal> {
+               // Note that the ChannelManager is NOT re-persisted on disk after this, so any changes are
+               // likely to be lost on restart!
                let (value, output_script, user_id) = {
                        let per_peer_state = self.per_peer_state.read().unwrap();
                        let peer_state_mutex = per_peer_state.get(counterparty_node_id)
@@ -5803,6 +5881,8 @@ where
        }
 
        fn internal_channel_ready(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReady) -> Result<(), MsgHandleErrInternal> {
+               // Note that the ChannelManager is NOT re-persisted on disk after this (unless we error
+               // closing a channel), so any changes are likely to be lost on restart!
                let per_peer_state = self.per_peer_state.read().unwrap();
                let peer_state_mutex = per_peer_state.get(counterparty_node_id)
                        .ok_or_else(|| {
@@ -5981,6 +6061,9 @@ where
                //encrypted with the same key. It's not immediately obvious how to usefully exploit that,
                //but we should prevent it anyway.
 
+               // Note that the ChannelManager is NOT re-persisted on disk after this (unless we error
+               // closing a channel), so any changes are likely to be lost on restart!
+
                let decoded_hop_res = self.decode_update_add_htlc_onion(msg);
                let per_peer_state = self.per_peer_state.read().unwrap();
                let peer_state_mutex = per_peer_state.get(counterparty_node_id)
@@ -6047,6 +6130,17 @@ where
                                hash_map::Entry::Occupied(mut chan_phase_entry) => {
                                        if let ChannelPhase::Funded(chan) = chan_phase_entry.get_mut() {
                                                let res = try_chan_phase_entry!(self, chan.update_fulfill_htlc(&msg), chan_phase_entry);
+                                               if let HTLCSource::PreviousHopData(prev_hop) = &res.0 {
+                                                       peer_state.actions_blocking_raa_monitor_updates.entry(msg.channel_id)
+                                                               .or_insert_with(Vec::new)
+                                                               .push(RAAMonitorUpdateBlockingAction::from_prev_hop_data(&prev_hop));
+                                               }
+                                               // Note that we do not need to push an `actions_blocking_raa_monitor_updates`
+                                               // entry here, even though we *do* need to block the next RAA monitor update.
+                                               // We do this instead in the `claim_funds_internal` by attaching a
+                                               // `ReleaseRAAChannelMonitorUpdate` action to the event generated when the
+                                               // outbound HTLC is claimed. This is guaranteed to all complete before we
+                                               // process the RAA as messages are processed from single peers serially.
                                                funding_txo = chan.context.get_funding_txo().expect("We won't accept a fulfill until funded");
                                                res
                                        } else {
@@ -6057,11 +6151,13 @@ where
                                hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close(format!("Got a message for a channel from the wrong node! No such channel for the passed counterparty_node_id {}", counterparty_node_id), msg.channel_id))
                        }
                };
-               self.claim_funds_internal(htlc_source, msg.payment_preimage.clone(), Some(forwarded_htlc_value), false, funding_txo);
+               self.claim_funds_internal(htlc_source, msg.payment_preimage.clone(), Some(forwarded_htlc_value), false, Some(*counterparty_node_id), funding_txo);
                Ok(())
        }
 
        fn internal_update_fail_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFailHTLC) -> Result<(), MsgHandleErrInternal> {
+               // Note that the ChannelManager is NOT re-persisted on disk after this (unless we error
+               // closing a channel), so any changes are likely to be lost on restart!
                let per_peer_state = self.per_peer_state.read().unwrap();
                let peer_state_mutex = per_peer_state.get(counterparty_node_id)
                        .ok_or_else(|| {
@@ -6085,6 +6181,8 @@ where
        }
 
        fn internal_update_fail_malformed_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFailMalformedHTLC) -> Result<(), MsgHandleErrInternal> {
+               // Note that the ChannelManager is NOT re-persisted on disk after this (unless we error
+               // closing a channel), so any changes are likely to be lost on restart!
                let per_peer_state = self.per_peer_state.read().unwrap();
                let peer_state_mutex = per_peer_state.get(counterparty_node_id)
                        .ok_or_else(|| {
@@ -6259,6 +6357,23 @@ where
                })
        }
 
+       #[cfg(any(test, feature = "_test_utils"))]
+       pub(crate) fn test_raa_monitor_updates_held(&self,
+               counterparty_node_id: PublicKey, channel_id: ChannelId
+       ) -> bool {
+               let per_peer_state = self.per_peer_state.read().unwrap();
+               if let Some(peer_state_mtx) = per_peer_state.get(&counterparty_node_id) {
+                       let mut peer_state_lck = peer_state_mtx.lock().unwrap();
+                       let peer_state = &mut *peer_state_lck;
+
+                       if let Some(chan) = peer_state.channel_by_id.get(&channel_id) {
+                               return self.raa_monitor_updates_held(&peer_state.actions_blocking_raa_monitor_updates,
+                                       chan.context().get_funding_txo().unwrap(), counterparty_node_id);
+                       }
+               }
+               false
+       }
+
        fn internal_revoke_and_ack(&self, counterparty_node_id: &PublicKey, msg: &msgs::RevokeAndACK) -> Result<(), MsgHandleErrInternal> {
                let (htlcs_to_fail, res) = {
                        let per_peer_state = self.per_peer_state.read().unwrap();
@@ -6356,19 +6471,19 @@ where
                Ok(())
        }
 
-       /// Returns ShouldPersist if anything changed, otherwise either SkipPersist or an Err.
+       /// Returns DoPersist if anything changed, otherwise either SkipPersistNoEvents or an Err.
        fn internal_channel_update(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelUpdate) -> Result<NotifyOption, MsgHandleErrInternal> {
                let (chan_counterparty_node_id, chan_id) = match self.short_to_chan_info.read().unwrap().get(&msg.contents.short_channel_id) {
                        Some((cp_id, chan_id)) => (cp_id.clone(), chan_id.clone()),
                        None => {
                                // It's not a local channel
-                               return Ok(NotifyOption::SkipPersist)
+                               return Ok(NotifyOption::SkipPersistNoEvents)
                        }
                };
                let per_peer_state = self.per_peer_state.read().unwrap();
                let peer_state_mutex_opt = per_peer_state.get(&chan_counterparty_node_id);
                if peer_state_mutex_opt.is_none() {
-                       return Ok(NotifyOption::SkipPersist)
+                       return Ok(NotifyOption::SkipPersistNoEvents)
                }
                let mut peer_state_lock = peer_state_mutex_opt.unwrap().lock().unwrap();
                let peer_state = &mut *peer_state_lock;
@@ -6380,14 +6495,14 @@ where
                                                        // If the announcement is about a channel of ours which is public, some
                                                        // other peer may simply be forwarding all its gossip to us. Don't provide
                                                        // a scary-looking error message and return Ok instead.
-                                                       return Ok(NotifyOption::SkipPersist);
+                                                       return Ok(NotifyOption::SkipPersistNoEvents);
                                                }
                                                return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a channel_update for a channel from the wrong node - it shouldn't know about our private channels!".to_owned(), chan_id));
                                        }
                                        let were_node_one = self.get_our_node_id().serialize()[..] < chan.context.get_counterparty_node_id().serialize()[..];
                                        let msg_from_node_one = msg.contents.flags & 1 == 0;
                                        if were_node_one == msg_from_node_one {
-                                               return Ok(NotifyOption::SkipPersist);
+                                               return Ok(NotifyOption::SkipPersistNoEvents);
                                        } else {
                                                log_debug!(self.logger, "Received channel_update for channel {}.", chan_id);
                                                try_chan_phase_entry!(self, chan.channel_update(&msg), chan_phase_entry);
@@ -6397,12 +6512,12 @@ where
                                                "Got a channel_update for an unfunded channel!".into())), chan_phase_entry);
                                }
                        },
-                       hash_map::Entry::Vacant(_) => return Ok(NotifyOption::SkipPersist)
+                       hash_map::Entry::Vacant(_) => return Ok(NotifyOption::SkipPersistNoEvents)
                }
                Ok(NotifyOption::DoPersist)
        }
 
-       fn internal_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) -> Result<(), MsgHandleErrInternal> {
+       fn internal_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) -> Result<NotifyOption, MsgHandleErrInternal> {
                let htlc_forwards;
                let need_lnd_workaround = {
                        let per_peer_state = self.per_peer_state.read().unwrap();
@@ -6458,14 +6573,16 @@ where
                        }
                };
 
+               let mut persist = NotifyOption::SkipPersistHandleEvents;
                if let Some(forwards) = htlc_forwards {
                        self.forward_htlcs(&mut [forwards][..]);
+                       persist = NotifyOption::DoPersist;
                }
 
                if let Some(channel_ready_msg) = need_lnd_workaround {
                        self.internal_channel_ready(counterparty_node_id, &channel_ready_msg)?;
                }
-               Ok(())
+               Ok(persist)
        }
 
        /// Process pending events from the [`chain::Watch`], returning whether any events were processed.
@@ -6480,8 +6597,8 @@ where
                                match monitor_event {
                                        MonitorEvent::HTLCEvent(htlc_update) => {
                                                if let Some(preimage) = htlc_update.payment_preimage {
-                                                       log_trace!(self.logger, "Claiming HTLC with preimage {} from our monitor", &preimage);
-                                                       self.claim_funds_internal(htlc_update.source, preimage, htlc_update.htlc_value_satoshis.map(|v| v * 1000), true, funding_outpoint);
+                                                       log_trace!(self.logger, "Claiming HTLC with preimage {} from our monitor", preimage);
+                                                       self.claim_funds_internal(htlc_update.source, preimage, htlc_update.htlc_value_satoshis.map(|v| v * 1000), true, counterparty_node_id, funding_outpoint);
                                                } else {
                                                        log_trace!(self.logger, "Failing HTLC with hash {} from our monitor", &htlc_update.payment_hash);
                                                        let receiver = HTLCDestination::NextHopChannel { node_id: counterparty_node_id, channel_id: funding_outpoint.to_channel_id() };
@@ -7015,8 +7132,8 @@ where
        /// the `MessageSendEvent`s to the specific peer they were generated under.
        fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent> {
                let events = RefCell::new(Vec::new());
-               PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
-                       let mut result = self.process_background_events();
+               PersistenceNotifierGuard::optionally_notify(self, || {
+                       let mut result = NotifyOption::SkipPersistNoEvents;
 
                        // TODO: This behavior should be documented. It's unintuitive that we query
                        // ChannelMonitors when clearing other events.
@@ -7097,8 +7214,9 @@ where
        }
 
        fn block_disconnected(&self, header: &BlockHeader, height: u32) {
-               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock,
-                       &self.persistence_notifier, || -> NotifyOption { NotifyOption::DoPersist });
+               let _persistence_guard =
+                       PersistenceNotifierGuard::optionally_notify_skipping_background_events(
+                               self, || -> NotifyOption { NotifyOption::DoPersist });
                let new_height = height - 1;
                {
                        let mut best_block = self.best_block.write().unwrap();
@@ -7132,8 +7250,9 @@ where
                let block_hash = header.block_hash();
                log_trace!(self.logger, "{} transactions included in block {} at height {} provided", txdata.len(), block_hash, height);
 
-               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock,
-                       &self.persistence_notifier, || -> NotifyOption { NotifyOption::DoPersist });
+               let _persistence_guard =
+                       PersistenceNotifierGuard::optionally_notify_skipping_background_events(
+                               self, || -> NotifyOption { NotifyOption::DoPersist });
                self.do_chain_event(Some(height), |channel| channel.transactions_confirmed(&block_hash, height, txdata, self.genesis_hash.clone(), &self.node_signer, &self.default_configuration, &self.logger)
                        .map(|(a, b)| (a, Vec::new(), b)));
 
@@ -7152,8 +7271,9 @@ where
                let block_hash = header.block_hash();
                log_trace!(self.logger, "New best block: {} at height {}", block_hash, height);
 
-               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock,
-                       &self.persistence_notifier, || -> NotifyOption { NotifyOption::DoPersist });
+               let _persistence_guard =
+                       PersistenceNotifierGuard::optionally_notify_skipping_background_events(
+                               self, || -> NotifyOption { NotifyOption::DoPersist });
                *self.best_block.write().unwrap() = BestBlock::new(block_hash, height);
 
                self.do_chain_event(Some(height), |channel| channel.best_block_updated(height, header.time, self.genesis_hash.clone(), &self.node_signer, &self.default_configuration, &self.logger));
@@ -7196,8 +7316,9 @@ where
        }
 
        fn transaction_unconfirmed(&self, txid: &Txid) {
-               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock,
-                       &self.persistence_notifier, || -> NotifyOption { NotifyOption::DoPersist });
+               let _persistence_guard =
+                       PersistenceNotifierGuard::optionally_notify_skipping_background_events(
+                               self, || -> NotifyOption { NotifyOption::DoPersist });
                self.do_chain_event(None, |channel| {
                        if let Some(funding_txo) = channel.context.get_funding_txo() {
                                if funding_txo.txid == *txid {
@@ -7380,18 +7501,26 @@ where
                }
        }
 
-       /// Gets a [`Future`] that completes when this [`ChannelManager`] needs to be persisted.
+       /// Gets a [`Future`] that completes when this [`ChannelManager`] may need to be persisted or
+       /// may have events that need processing.
+       ///
+       /// In order to check if this [`ChannelManager`] needs persisting, call
+       /// [`Self::get_and_clear_needs_persistence`].
        ///
        /// Note that callbacks registered on the [`Future`] MUST NOT call back into this
        /// [`ChannelManager`] and should instead register actions to be taken later.
-       ///
-       pub fn get_persistable_update_future(&self) -> Future {
-               self.persistence_notifier.get_future()
+       pub fn get_event_or_persistence_needed_future(&self) -> Future {
+               self.event_persist_notifier.get_future()
+       }
+
+       /// Returns true if this [`ChannelManager`] needs to be persisted.
+       pub fn get_and_clear_needs_persistence(&self) -> bool {
+               self.needs_persist_flag.swap(false, Ordering::AcqRel)
        }
 
        #[cfg(any(test, feature = "_test_utils"))]
-       pub fn get_persistence_condvar_value(&self) -> bool {
-               self.persistence_notifier.notify_pending()
+       pub fn get_event_or_persist_condvar_value(&self) -> bool {
+               self.event_persist_notifier.notify_pending()
        }
 
        /// Gets the latest best block which was connected either via the [`chain::Listen`] or
@@ -7448,8 +7577,21 @@ where
        L::Target: Logger,
 {
        fn handle_open_channel(&self, counterparty_node_id: &PublicKey, msg: &msgs::OpenChannel) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               let _ = handle_error!(self, self.internal_open_channel(counterparty_node_id, msg), *counterparty_node_id);
+               // Note that we never need to persist the updated ChannelManager for an inbound
+               // open_channel message - pre-funded channels are never written so there should be no
+               // change to the contents.
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(self, || {
+                       let res = self.internal_open_channel(counterparty_node_id, msg);
+                       let persist = match &res {
+                               Err(e) if e.closes_channel() => {
+                                       debug_assert!(false, "We shouldn't close a new channel");
+                                       NotifyOption::DoPersist
+                               },
+                               _ => NotifyOption::SkipPersistHandleEvents,
+                       };
+                       let _ = handle_error!(self, res, *counterparty_node_id);
+                       persist
+               });
        }
 
        fn handle_open_channel_v2(&self, counterparty_node_id: &PublicKey, msg: &msgs::OpenChannelV2) {
@@ -7459,8 +7601,13 @@ where
        }
 
        fn handle_accept_channel(&self, counterparty_node_id: &PublicKey, msg: &msgs::AcceptChannel) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               let _ = handle_error!(self, self.internal_accept_channel(counterparty_node_id, msg), *counterparty_node_id);
+               // Note that we never need to persist the updated ChannelManager for an inbound
+               // accept_channel message - pre-funded channels are never written so there should be no
+               // change to the contents.
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(self, || {
+                       let _ = handle_error!(self, self.internal_accept_channel(counterparty_node_id, msg), *counterparty_node_id);
+                       NotifyOption::SkipPersistHandleEvents
+               });
        }
 
        fn handle_accept_channel_v2(&self, counterparty_node_id: &PublicKey, msg: &msgs::AcceptChannelV2) {
@@ -7480,8 +7627,19 @@ where
        }
 
        fn handle_channel_ready(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReady) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               let _ = handle_error!(self, self.internal_channel_ready(counterparty_node_id, msg), *counterparty_node_id);
+               // Note that we never need to persist the updated ChannelManager for an inbound
+               // channel_ready message - while the channel's state will change, any channel_ready message
+               // will ultimately be re-sent on startup and the `ChannelMonitor` won't be updated so we
+               // will not force-close the channel on startup.
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(self, || {
+                       let res = self.internal_channel_ready(counterparty_node_id, msg);
+                       let persist = match &res {
+                               Err(e) if e.closes_channel() => NotifyOption::DoPersist,
+                               _ => NotifyOption::SkipPersistHandleEvents,
+                       };
+                       let _ = handle_error!(self, res, *counterparty_node_id);
+                       persist
+               });
        }
 
        fn handle_shutdown(&self, counterparty_node_id: &PublicKey, msg: &msgs::Shutdown) {
@@ -7495,8 +7653,19 @@ where
        }
 
        fn handle_update_add_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateAddHTLC) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               let _ = handle_error!(self, self.internal_update_add_htlc(counterparty_node_id, msg), *counterparty_node_id);
+               // Note that we never need to persist the updated ChannelManager for an inbound
+               // update_add_htlc message - the message itself doesn't change our channel state only the
+               // `commitment_signed` message afterwards will.
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(self, || {
+                       let res = self.internal_update_add_htlc(counterparty_node_id, msg);
+                       let persist = match &res {
+                               Err(e) if e.closes_channel() => NotifyOption::DoPersist,
+                               Err(_) => NotifyOption::SkipPersistHandleEvents,
+                               Ok(()) => NotifyOption::SkipPersistNoEvents,
+                       };
+                       let _ = handle_error!(self, res, *counterparty_node_id);
+                       persist
+               });
        }
 
        fn handle_update_fulfill_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFulfillHTLC) {
@@ -7505,13 +7674,35 @@ where
        }
 
        fn handle_update_fail_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFailHTLC) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               let _ = handle_error!(self, self.internal_update_fail_htlc(counterparty_node_id, msg), *counterparty_node_id);
+               // Note that we never need to persist the updated ChannelManager for an inbound
+               // update_fail_htlc message - the message itself doesn't change our channel state only the
+               // `commitment_signed` message afterwards will.
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(self, || {
+                       let res = self.internal_update_fail_htlc(counterparty_node_id, msg);
+                       let persist = match &res {
+                               Err(e) if e.closes_channel() => NotifyOption::DoPersist,
+                               Err(_) => NotifyOption::SkipPersistHandleEvents,
+                               Ok(()) => NotifyOption::SkipPersistNoEvents,
+                       };
+                       let _ = handle_error!(self, res, *counterparty_node_id);
+                       persist
+               });
        }
 
        fn handle_update_fail_malformed_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFailMalformedHTLC) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               let _ = handle_error!(self, self.internal_update_fail_malformed_htlc(counterparty_node_id, msg), *counterparty_node_id);
+               // Note that we never need to persist the updated ChannelManager for an inbound
+               // update_fail_malformed_htlc message - the message itself doesn't change our channel state
+               // only the `commitment_signed` message afterwards will.
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(self, || {
+                       let res = self.internal_update_fail_malformed_htlc(counterparty_node_id, msg);
+                       let persist = match &res {
+                               Err(e) if e.closes_channel() => NotifyOption::DoPersist,
+                               Err(_) => NotifyOption::SkipPersistHandleEvents,
+                               Ok(()) => NotifyOption::SkipPersistNoEvents,
+                       };
+                       let _ = handle_error!(self, res, *counterparty_node_id);
+                       persist
+               });
        }
 
        fn handle_commitment_signed(&self, counterparty_node_id: &PublicKey, msg: &msgs::CommitmentSigned) {
@@ -7525,8 +7716,19 @@ where
        }
 
        fn handle_update_fee(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFee) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               let _ = handle_error!(self, self.internal_update_fee(counterparty_node_id, msg), *counterparty_node_id);
+               // Note that we never need to persist the updated ChannelManager for an inbound
+               // update_fee message - the message itself doesn't change our channel state only the
+               // `commitment_signed` message afterwards will.
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(self, || {
+                       let res = self.internal_update_fee(counterparty_node_id, msg);
+                       let persist = match &res {
+                               Err(e) if e.closes_channel() => NotifyOption::DoPersist,
+                               Err(_) => NotifyOption::SkipPersistHandleEvents,
+                               Ok(()) => NotifyOption::SkipPersistNoEvents,
+                       };
+                       let _ = handle_error!(self, res, *counterparty_node_id);
+                       persist
+               });
        }
 
        fn handle_announcement_signatures(&self, counterparty_node_id: &PublicKey, msg: &msgs::AnnouncementSignatures) {
@@ -7535,23 +7737,32 @@ where
        }
 
        fn handle_channel_update(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelUpdate) {
-               PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
-                       let force_persist = self.process_background_events();
+               PersistenceNotifierGuard::optionally_notify(self, || {
                        if let Ok(persist) = handle_error!(self, self.internal_channel_update(counterparty_node_id, msg), *counterparty_node_id) {
-                               if force_persist == NotifyOption::DoPersist { NotifyOption::DoPersist } else { persist }
+                               persist
                        } else {
-                               NotifyOption::SkipPersist
+                               NotifyOption::DoPersist
                        }
                });
        }
 
        fn handle_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
-               let _ = handle_error!(self, self.internal_channel_reestablish(counterparty_node_id, msg), *counterparty_node_id);
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(self, || {
+                       let res = self.internal_channel_reestablish(counterparty_node_id, msg);
+                       let persist = match &res {
+                               Err(e) if e.closes_channel() => NotifyOption::DoPersist,
+                               Err(_) => NotifyOption::SkipPersistHandleEvents,
+                               Ok(persist) => *persist,
+                       };
+                       let _ = handle_error!(self, res, *counterparty_node_id);
+                       persist
+               });
        }
 
        fn peer_disconnected(&self, counterparty_node_id: &PublicKey) {
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
+               let _persistence_guard = PersistenceNotifierGuard::optionally_notify(
+                       self, || NotifyOption::SkipPersistHandleEvents);
+
                let mut failed_channels = Vec::new();
                let mut per_peer_state = self.per_peer_state.write().unwrap();
                let remove_peer = {
@@ -7650,76 +7861,82 @@ where
                        return Err(());
                }
 
-               let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
+               let mut res = Ok(());
 
-               // If we have too many peers connected which don't have funded channels, disconnect the
-               // peer immediately (as long as it doesn't have funded channels). If we have a bunch of
-               // unfunded channels taking up space in memory for disconnected peers, we still let new
-               // peers connect, but we'll reject new channels from them.
-               let connected_peers_without_funded_channels = self.peers_without_funded_channels(|node| node.is_connected);
-               let inbound_peer_limited = inbound && connected_peers_without_funded_channels >= MAX_NO_CHANNEL_PEERS;
+               PersistenceNotifierGuard::optionally_notify(self, || {
+                       // If we have too many peers connected which don't have funded channels, disconnect the
+                       // peer immediately (as long as it doesn't have funded channels). If we have a bunch of
+                       // unfunded channels taking up space in memory for disconnected peers, we still let new
+                       // peers connect, but we'll reject new channels from them.
+                       let connected_peers_without_funded_channels = self.peers_without_funded_channels(|node| node.is_connected);
+                       let inbound_peer_limited = inbound && connected_peers_without_funded_channels >= MAX_NO_CHANNEL_PEERS;
 
-               {
-                       let mut peer_state_lock = self.per_peer_state.write().unwrap();
-                       match peer_state_lock.entry(counterparty_node_id.clone()) {
-                               hash_map::Entry::Vacant(e) => {
-                                       if inbound_peer_limited {
-                                               return Err(());
-                                       }
-                                       e.insert(Mutex::new(PeerState {
-                                               channel_by_id: HashMap::new(),
-                                               inbound_channel_request_by_id: HashMap::new(),
-                                               latest_features: init_msg.features.clone(),
-                                               pending_msg_events: Vec::new(),
-                                               in_flight_monitor_updates: BTreeMap::new(),
-                                               monitor_update_blocked_actions: BTreeMap::new(),
-                                               actions_blocking_raa_monitor_updates: BTreeMap::new(),
-                                               is_connected: true,
-                                       }));
-                               },
-                               hash_map::Entry::Occupied(e) => {
-                                       let mut peer_state = e.get().lock().unwrap();
-                                       peer_state.latest_features = init_msg.features.clone();
-
-                                       let best_block_height = self.best_block.read().unwrap().height();
-                                       if inbound_peer_limited &&
-                                               Self::unfunded_channel_count(&*peer_state, best_block_height) ==
-                                               peer_state.channel_by_id.len()
-                                       {
-                                               return Err(());
-                                       }
+                       {
+                               let mut peer_state_lock = self.per_peer_state.write().unwrap();
+                               match peer_state_lock.entry(counterparty_node_id.clone()) {
+                                       hash_map::Entry::Vacant(e) => {
+                                               if inbound_peer_limited {
+                                                       res = Err(());
+                                                       return NotifyOption::SkipPersistNoEvents;
+                                               }
+                                               e.insert(Mutex::new(PeerState {
+                                                       channel_by_id: HashMap::new(),
+                                                       inbound_channel_request_by_id: HashMap::new(),
+                                                       latest_features: init_msg.features.clone(),
+                                                       pending_msg_events: Vec::new(),
+                                                       in_flight_monitor_updates: BTreeMap::new(),
+                                                       monitor_update_blocked_actions: BTreeMap::new(),
+                                                       actions_blocking_raa_monitor_updates: BTreeMap::new(),
+                                                       is_connected: true,
+                                               }));
+                                       },
+                                       hash_map::Entry::Occupied(e) => {
+                                               let mut peer_state = e.get().lock().unwrap();
+                                               peer_state.latest_features = init_msg.features.clone();
+
+                                               let best_block_height = self.best_block.read().unwrap().height();
+                                               if inbound_peer_limited &&
+                                                       Self::unfunded_channel_count(&*peer_state, best_block_height) ==
+                                                       peer_state.channel_by_id.len()
+                                               {
+                                                       res = Err(());
+                                                       return NotifyOption::SkipPersistNoEvents;
+                                               }
 
-                                       debug_assert!(!peer_state.is_connected, "A peer shouldn't be connected twice");
-                                       peer_state.is_connected = true;
-                               },
+                                               debug_assert!(!peer_state.is_connected, "A peer shouldn't be connected twice");
+                                               peer_state.is_connected = true;
+                                       },
+                               }
                        }
-               }
 
-               log_debug!(self.logger, "Generating channel_reestablish events for {}", log_pubkey!(counterparty_node_id));
+                       log_debug!(self.logger, "Generating channel_reestablish events for {}", log_pubkey!(counterparty_node_id));
 
-               let per_peer_state = self.per_peer_state.read().unwrap();
-               if let Some(peer_state_mutex) = per_peer_state.get(counterparty_node_id) {
-                       let mut peer_state_lock = peer_state_mutex.lock().unwrap();
-                       let peer_state = &mut *peer_state_lock;
-                       let pending_msg_events = &mut peer_state.pending_msg_events;
+                       let per_peer_state = self.per_peer_state.read().unwrap();
+                       if let Some(peer_state_mutex) = per_peer_state.get(counterparty_node_id) {
+                               let mut peer_state_lock = peer_state_mutex.lock().unwrap();
+                               let peer_state = &mut *peer_state_lock;
+                               let pending_msg_events = &mut peer_state.pending_msg_events;
 
-                       peer_state.channel_by_id.iter_mut().filter_map(|(_, phase)|
-                               if let ChannelPhase::Funded(chan) = phase { Some(chan) } else {
-                                       // Since unfunded channel maps are cleared upon disconnecting a peer, and they're not persisted
-                                       // (so won't be recovered after a crash), they shouldn't exist here and we would never need to
-                                       // worry about closing and removing them.
-                                       debug_assert!(false);
-                                       None
-                               }
-                       ).for_each(|chan| {
-                               pending_msg_events.push(events::MessageSendEvent::SendChannelReestablish {
-                                       node_id: chan.context.get_counterparty_node_id(),
-                                       msg: chan.get_channel_reestablish(&self.logger),
+                               peer_state.channel_by_id.iter_mut().filter_map(|(_, phase)|
+                                       if let ChannelPhase::Funded(chan) = phase { Some(chan) } else {
+                                               // Since unfunded channel maps are cleared upon disconnecting a peer, and they're not persisted
+                                               // (so won't be recovered after a crash), they shouldn't exist here and we would never need to
+                                               // worry about closing and removing them.
+                                               debug_assert!(false);
+                                               None
+                                       }
+                               ).for_each(|chan| {
+                                       pending_msg_events.push(events::MessageSendEvent::SendChannelReestablish {
+                                               node_id: chan.context.get_counterparty_node_id(),
+                                               msg: chan.get_channel_reestablish(&self.logger),
+                                       });
                                });
-                       });
-               }
-               //TODO: Also re-broadcast announcement_signatures
-               Ok(())
+                       }
+
+                       return NotifyOption::SkipPersistHandleEvents;
+                       //TODO: Also re-broadcast announcement_signatures
+               });
+               res
        }
 
        fn handle_error(&self, counterparty_node_id: &PublicKey, msg: &msgs::ErrorMessage) {
@@ -9301,6 +9518,7 @@ where
                                                                        // downstream chan is closed (because we don't have a
                                                                        // channel_id -> peer map entry).
                                                                        counterparty_opt.is_none(),
+                                                                       counterparty_opt.cloned().or(monitor.get_counterparty_node_id()),
                                                                        monitor.get_funding_txo().0))
                                                        } else { None }
                                                } else {
@@ -9562,7 +9780,9 @@ where
                        pending_background_events: Mutex::new(pending_background_events),
                        total_consistency_lock: RwLock::new(()),
                        background_events_processed_since_startup: AtomicBool::new(false),
-                       persistence_notifier: Notifier::new(),
+
+                       event_persist_notifier: Notifier::new(),
+                       needs_persist_flag: AtomicBool::new(false),
 
                        entropy_source: args.entropy_source,
                        node_signer: args.node_signer,
@@ -9579,12 +9799,12 @@ where
                        channel_manager.fail_htlc_backwards_internal(&source, &payment_hash, &reason, receiver);
                }
 
-               for (source, preimage, downstream_value, downstream_closed, downstream_funding) in pending_claims_to_replay {
+               for (source, preimage, downstream_value, downstream_closed, downstream_node_id, downstream_funding) in pending_claims_to_replay {
                        // We use `downstream_closed` in place of `from_onchain` here just as a guess - we
                        // don't remember in the `ChannelMonitor` where we got a preimage from, but if the
                        // channel is closed we just assume that it probably came from an on-chain claim.
                        channel_manager.claim_funds_internal(source, preimage, Some(downstream_value),
-                               downstream_closed, downstream_funding);
+                               downstream_closed, downstream_node_id, downstream_funding);
                }
 
                //TODO: Broadcast channel update for closed channels, but only after we've made a
@@ -9624,9 +9844,9 @@ mod tests {
 
                // All nodes start with a persistable update pending as `create_network` connects each node
                // with all other nodes to make most tests simpler.
-               assert!(nodes[0].node.get_persistable_update_future().poll_is_complete());
-               assert!(nodes[1].node.get_persistable_update_future().poll_is_complete());
-               assert!(nodes[2].node.get_persistable_update_future().poll_is_complete());
+               assert!(nodes[0].node.get_event_or_persistence_needed_future().poll_is_complete());
+               assert!(nodes[1].node.get_event_or_persistence_needed_future().poll_is_complete());
+               assert!(nodes[2].node.get_event_or_persistence_needed_future().poll_is_complete());
 
                let mut chan = create_announced_chan_between_nodes(&nodes, 0, 1);
 
@@ -9640,19 +9860,19 @@ mod tests {
                        &nodes[0].node.get_our_node_id()).pop().unwrap();
 
                // The first two nodes (which opened a channel) should now require fresh persistence
-               assert!(nodes[0].node.get_persistable_update_future().poll_is_complete());
-               assert!(nodes[1].node.get_persistable_update_future().poll_is_complete());
+               assert!(nodes[0].node.get_event_or_persistence_needed_future().poll_is_complete());
+               assert!(nodes[1].node.get_event_or_persistence_needed_future().poll_is_complete());
                // ... but the last node should not.
-               assert!(!nodes[2].node.get_persistable_update_future().poll_is_complete());
+               assert!(!nodes[2].node.get_event_or_persistence_needed_future().poll_is_complete());
                // After persisting the first two nodes they should no longer need fresh persistence.
-               assert!(!nodes[0].node.get_persistable_update_future().poll_is_complete());
-               assert!(!nodes[1].node.get_persistable_update_future().poll_is_complete());
+               assert!(!nodes[0].node.get_event_or_persistence_needed_future().poll_is_complete());
+               assert!(!nodes[1].node.get_event_or_persistence_needed_future().poll_is_complete());
 
                // Node 3, unrelated to the only channel, shouldn't care if it receives a channel_update
                // about the channel.
                nodes[2].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &chan.0);
                nodes[2].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &chan.1);
-               assert!(!nodes[2].node.get_persistable_update_future().poll_is_complete());
+               assert!(!nodes[2].node.get_event_or_persistence_needed_future().poll_is_complete());
 
                // The nodes which are a party to the channel should also ignore messages from unrelated
                // parties.
@@ -9660,8 +9880,8 @@ mod tests {
                nodes[0].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.1);
                nodes[1].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.0);
                nodes[1].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.1);
-               assert!(!nodes[0].node.get_persistable_update_future().poll_is_complete());
-               assert!(!nodes[1].node.get_persistable_update_future().poll_is_complete());
+               assert!(!nodes[0].node.get_event_or_persistence_needed_future().poll_is_complete());
+               assert!(!nodes[1].node.get_event_or_persistence_needed_future().poll_is_complete());
 
                // At this point the channel info given by peers should still be the same.
                assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
@@ -9678,8 +9898,8 @@ mod tests {
                // persisted and that its channel info remains the same.
                nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &as_update);
                nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &bs_update);
-               assert!(!nodes[0].node.get_persistable_update_future().poll_is_complete());
-               assert!(!nodes[1].node.get_persistable_update_future().poll_is_complete());
+               assert!(!nodes[0].node.get_event_or_persistence_needed_future().poll_is_complete());
+               assert!(!nodes[1].node.get_event_or_persistence_needed_future().poll_is_complete());
                assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
                assert_eq!(nodes[1].node.list_channels()[0], node_b_chan_info);
 
@@ -9687,8 +9907,8 @@ mod tests {
                // the channel info has updated.
                nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &bs_update);
                nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &as_update);
-               assert!(nodes[0].node.get_persistable_update_future().poll_is_complete());
-               assert!(nodes[1].node.get_persistable_update_future().poll_is_complete());
+               assert!(nodes[0].node.get_event_or_persistence_needed_future().poll_is_complete());
+               assert!(nodes[1].node.get_event_or_persistence_needed_future().poll_is_complete());
                assert_ne!(nodes[0].node.list_channels()[0], node_a_chan_info);
                assert_ne!(nodes[1].node.list_channels()[0], node_b_chan_info);
        }
@@ -9839,7 +10059,7 @@ mod tests {
 
                // To start (1), send a regular payment but don't claim it.
                let expected_route = [&nodes[1]];
-               let (payment_preimage, payment_hash, _) = route_payment(&nodes[0], &expected_route, 100_000);
+               let (payment_preimage, payment_hash, ..) = route_payment(&nodes[0], &expected_route, 100_000);
 
                // Next, attempt a keysend payment and make sure it fails.
                let route_params = RouteParameters::from_payment_params_and_value(