Append backwards-compat TLVs to serialization of larger structs
[rust-lightning] / lightning / src / chain / channelmonitor.rs
index b46a2df13eea8d8c462e1df72dd6dca9fac2b45f..e7d5e32264ff6986f1956ed63b8c4ebb8996af77 100644 (file)
 //! ChannelMonitors should do so). Thus, if you're building rust-lightning into an HSM or other
 //! security-domain-separated system design, you should consider having multiple paths for
 //! ChannelMonitors to get out of the HSM and onto monitoring devices.
-//!
-//! [`chain::Watch`]: ../trait.Watch.html
 
-use bitcoin::blockdata::block::BlockHeader;
+use bitcoin::blockdata::block::{Block, BlockHeader};
 use bitcoin::blockdata::transaction::{TxOut,Transaction};
 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
 use bitcoin::blockdata::script::{Script, Builder};
@@ -36,23 +34,28 @@ use bitcoin::secp256k1::{Secp256k1,Signature};
 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
 use bitcoin::secp256k1;
 
+use ln::{PaymentHash, PaymentPreimage};
 use ln::msgs::DecodeError;
 use ln::chan_utils;
 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCType, ChannelTransactionParameters, HolderCommitmentTransaction};
-use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
+use ln::channelmanager::{BestBlock, HTLCSource};
 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
+use chain;
+use chain::WatchedOutput;
 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use chain::transaction::{OutPoint, TransactionData};
-use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys, KeysInterface};
+use chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
+use chain::Filter;
 use util::logger::Logger;
 use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48};
 use util::byte_utils;
 use util::events::Event;
 
-use std::collections::{HashMap, HashSet, hash_map};
-use std::{cmp, mem};
-use std::ops::Deref;
+use std::collections::{HashMap, HashSet};
+use core::{cmp, mem};
 use std::io::Error;
+use core::ops::Deref;
+use std::sync::Mutex;
 
 /// An update generated by the underlying Channel itself which contains some new information the
 /// ChannelMonitor should be made aware of.
@@ -72,8 +75,6 @@ pub struct ChannelMonitorUpdate {
        /// The only instance where update_id values are not strictly increasing is the case where we
        /// allow post-force-close updates with a special update ID of [`CLOSED_CHANNEL_UPDATE_ID`]. See
        /// its docs for more details.
-       ///
-       /// [`CLOSED_CHANNEL_UPDATE_ID`]: constant.CLOSED_CHANNEL_UPDATE_ID.html
        pub update_id: u64,
 }
 
@@ -84,7 +85,7 @@ pub struct ChannelMonitorUpdate {
 /// then we allow the `ChannelManager` to send a `ChannelMonitorUpdate` with this update ID,
 /// with the update providing said payment preimage. No other update types are allowed after
 /// force-close.
-pub const CLOSED_CHANNEL_UPDATE_ID: u64 = std::u64::MAX;
+pub const CLOSED_CHANNEL_UPDATE_ID: u64 = core::u64::MAX;
 
 impl Writeable for ChannelMonitorUpdate {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
@@ -100,7 +101,7 @@ impl Readable for ChannelMonitorUpdate {
        fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
                let update_id: u64 = Readable::read(r)?;
                let len: u64 = Readable::read(r)?;
-               let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<ChannelMonitorUpdateStep>()));
+               let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<ChannelMonitorUpdateStep>()));
                for _ in 0..len {
                        updates.push(Readable::read(r)?);
                }
@@ -174,7 +175,7 @@ pub enum ChannelMonitorUpdateErr {
 /// means you tried to update a monitor for a different channel or the ChannelMonitorUpdate was
 /// corrupted.
 /// Contains a developer-readable error message.
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct MonitorUpdateError(pub &'static str);
 
 /// An event to be processed by the ChannelManager.
@@ -190,8 +191,6 @@ pub enum MonitorEvent {
 /// Simple structure sent back by `chain::Watch` when an HTLC from a forward channel is detected on
 /// chain. Used to update the corresponding HTLC in the backward channel. Failing to pass the
 /// preimage claim backward will lead to loss of funds.
-///
-/// [`chain::Watch`]: ../trait.Watch.html
 #[derive(Clone, PartialEq)]
 pub struct HTLCUpdate {
        pub(crate) payment_hash: PaymentHash,
@@ -207,7 +206,7 @@ pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 /// HTLC-Success transaction.
 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
 /// transaction confirmed (and we use it in a few more, equivalent, places).
-pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
+pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing
@@ -223,11 +222,11 @@ pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
 pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
 /// Number of blocks we wait on seeing a HTLC output being solved before we fail corresponding inbound
 /// HTLCs. This prevents us from failing backwards and then getting a reorg resulting in us losing money.
-/// We use also this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
-/// It may cause spurrious generation of bumped claim txn but that's allright given the outpoint is already
-/// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
-/// keeping bumping another claim tx to solve the outpoint.
-pub(crate) const ANTI_REORG_DELAY: u32 = 6;
+// We also use this delay to be sure we can remove our in-flight claim txn from bump candidates buffer.
+// It may cause spurious generation of bumped claim txn but that's alright given the outpoint is already
+// solved by a previous claim tx. What we want to avoid is reorg evicting our claim tx and us not
+// keep bumping another claim tx to solve the outpoint.
+pub const ANTI_REORG_DELAY: u32 = 6;
 /// Number of blocks before confirmation at which we fail back an un-relayed HTLC or at which we
 /// refuse to accept a new HTLC.
 ///
@@ -467,9 +466,30 @@ pub(crate) struct ClaimRequest {
        pub(crate) witness_data: InputMaterial
 }
 
+/// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
+/// transaction causing it.
+///
+/// Used to determine when the on-chain event can be considered safe from a chain reorganization.
+#[derive(PartialEq)]
+struct OnchainEventEntry {
+       txid: Txid,
+       height: u32,
+       event: OnchainEvent,
+}
+
+impl OnchainEventEntry {
+       fn confirmation_threshold(&self) -> u32 {
+               self.height + ANTI_REORG_DELAY - 1
+       }
+
+       fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
+               height >= self.confirmation_threshold()
+       }
+}
+
 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
-#[derive(Clone, PartialEq)]
+#[derive(PartialEq)]
 enum OnchainEvent {
        /// HTLC output getting solved by a timeout, at maturation we pass upstream payment source information to solve
        /// inbound HTLC in backward channel. Note, in case of preimage, we pass info to upstream without delay as we can
@@ -482,9 +502,6 @@ enum OnchainEvent {
        },
 }
 
-const SERIALIZATION_VERSION: u8 = 1;
-const MIN_SERIALIZATION_VERSION: u8 = 1;
-
 #[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
 #[derive(Clone)]
 pub(crate) enum ChannelMonitorUpdateStep {
@@ -618,12 +635,19 @@ impl Readable for ChannelMonitorUpdateStep {
 /// reloaded at deserialize-time. Thus, you must ensure that, when handling events, all events
 /// gotten are fully handled before re-serializing the new state.
 ///
-/// Note that the deserializer is only implemented for (Sha256dHash, ChannelMonitor), which
+/// Note that the deserializer is only implemented for (BlockHash, ChannelMonitor), which
 /// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
 /// the "reorg path" (ie disconnecting blocks until you find a common ancestor from both the
 /// returned block hash and the the current chain and then reconnecting blocks to get to the
 /// best chain) upon deserializing the object!
-pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
+pub struct ChannelMonitor<Signer: Sign> {
+       #[cfg(test)]
+       pub(crate) inner: Mutex<ChannelMonitorImpl<Signer>>,
+       #[cfg(not(test))]
+       inner: Mutex<ChannelMonitorImpl<Signer>>,
+}
+
+pub(crate) struct ChannelMonitorImpl<Signer: Sign> {
        latest_update_id: u64,
        commitment_transaction_number_obscure_factor: u64,
 
@@ -632,7 +656,7 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        counterparty_payment_script: Script,
        shutdown_script: Script,
 
-       key_derivation_params: (u64, u64),
+       channel_keys_id: [u8; 32],
        holder_revocation_basepoint: PublicKey,
        funding_info: (OutPoint, Script),
        current_counterparty_commitment_txid: Option<Txid>,
@@ -679,10 +703,10 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        pending_monitor_events: Vec<MonitorEvent>,
        pending_events: Vec<Event>,
 
-       // Used to track onchain events, i.e transactions parts of channels confirmed on chain, on which
-       // we have to take actions once they reach enough confs. Key is a block height timer, i.e we enforce
-       // actions when we receive a block with given height. Actions depend on OnchainEvent type.
-       onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
+       // Used to track on-chain events (i.e., transactions part of channels confirmed on chain) on
+       // which to take actions once they reach enough confirmations. Each entry includes the
+       // transaction's id and the height when the transaction was confirmed on chain.
+       onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
 
        // If we get serialized out and re-read, we need to make sure that the chain monitoring
        // interface knows about the TXOs that we want to be notified of spends of. We could probably
@@ -691,9 +715,9 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        outputs_to_watch: HashMap<Txid, Vec<(u32, Script)>>,
 
        #[cfg(test)]
-       pub onchain_tx_handler: OnchainTxHandler<ChanSigner>,
+       pub onchain_tx_handler: OnchainTxHandler<Signer>,
        #[cfg(not(test))]
-       onchain_tx_handler: OnchainTxHandler<ChanSigner>,
+       onchain_tx_handler: OnchainTxHandler<Signer>,
 
        // This is set when the Channel[Manager] generated a ChannelMonitorUpdate which indicated the
        // channel has been force-closed. After this is set, no further holder commitment transaction
@@ -709,26 +733,41 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
        // remote monitor out-of-order with regards to the block view.
        holder_tx_signed: bool,
 
-       // We simply modify last_block_hash in Channel's block_connected so that serialization is
+       // We simply modify best_block in Channel's block_connected so that serialization is
        // consistent but hopefully the users' copy handles block_connected in a consistent way.
        // (we do *not*, however, update them in update_monitor to ensure any local user copies keep
-       // their last_block_hash from its state and not based on updated copies that didn't run through
+       // their best_block from its state and not based on updated copies that didn't run through
        // the full block_connected).
-       last_block_hash: BlockHash,
+       best_block: BestBlock,
+
        secp_ctx: Secp256k1<secp256k1::All>, //TODO: dedup this a bit...
 }
 
+/// Transaction outputs to watch for on-chain spends.
+pub type TransactionOutputs = (Txid, Vec<(u32, TxOut)>);
+
 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
 /// Used only in testing and fuzztarget to check serialization roundtrips don't change the
 /// underlying object
-impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
+impl<Signer: Sign> PartialEq for ChannelMonitor<Signer> {
+       fn eq(&self, other: &Self) -> bool {
+               let inner = self.inner.lock().unwrap();
+               let other = other.inner.lock().unwrap();
+               inner.eq(&other)
+       }
+}
+
+#[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
+/// Used only in testing and fuzztarget to check serialization roundtrips don't change the
+/// underlying object
+impl<Signer: Sign> PartialEq for ChannelMonitorImpl<Signer> {
        fn eq(&self, other: &Self) -> bool {
                if self.latest_update_id != other.latest_update_id ||
                        self.commitment_transaction_number_obscure_factor != other.commitment_transaction_number_obscure_factor ||
                        self.destination_script != other.destination_script ||
                        self.broadcasted_holder_revokable_script != other.broadcasted_holder_revokable_script ||
                        self.counterparty_payment_script != other.counterparty_payment_script ||
-                       self.key_derivation_params != other.key_derivation_params ||
+                       self.channel_keys_id != other.channel_keys_id ||
                        self.holder_revocation_basepoint != other.holder_revocation_basepoint ||
                        self.funding_info != other.funding_info ||
                        self.current_counterparty_commitment_txid != other.current_counterparty_commitment_txid ||
@@ -749,7 +788,7 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
                        self.payment_preimages != other.payment_preimages ||
                        self.pending_monitor_events != other.pending_monitor_events ||
                        self.pending_events.len() != other.pending_events.len() || // We trust events to round-trip properly
-                       self.onchain_events_waiting_threshold_conf != other.onchain_events_waiting_threshold_conf ||
+                       self.onchain_events_awaiting_threshold_conf != other.onchain_events_awaiting_threshold_conf ||
                        self.outputs_to_watch != other.outputs_to_watch ||
                        self.lockdown_from_offchain != other.lockdown_from_offchain ||
                        self.holder_tx_signed != other.holder_tx_signed
@@ -761,12 +800,18 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
        }
 }
 
-impl<ChanSigner: ChannelKeys> Writeable for ChannelMonitor<ChanSigner> {
+impl<Signer: Sign> Writeable for ChannelMonitor<Signer> {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
+               self.inner.lock().unwrap().write(writer)
+       }
+}
+
+const SERIALIZATION_VERSION: u8 = 1;
+const MIN_SERIALIZATION_VERSION: u8 = 1;
+
+impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
-               //TODO: We still write out all the serialization here manually instead of using the fancy
-               //serialization framework we have, we should migrate things over to it.
-               writer.write_all(&[SERIALIZATION_VERSION; 1])?;
-               writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
+               write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
 
                self.latest_update_id.write(writer)?;
 
@@ -786,7 +831,7 @@ impl<ChanSigner: ChannelKeys> Writeable for ChannelMonitor<ChanSigner> {
                self.counterparty_payment_script.write(writer)?;
                self.shutdown_script.write(writer)?;
 
-               self.key_derivation_params.write(writer)?;
+               self.channel_keys_id.write(writer)?;
                self.holder_revocation_basepoint.write(writer)?;
                writer.write_all(&self.funding_info.0.txid[..])?;
                writer.write_all(&byte_utils::be16_to_array(self.funding_info.0.index))?;
@@ -909,24 +954,23 @@ impl<ChanSigner: ChannelKeys> Writeable for ChannelMonitor<ChanSigner> {
                        event.write(writer)?;
                }
 
-               self.last_block_hash.write(writer)?;
+               self.best_block.block_hash().write(writer)?;
+               writer.write_all(&byte_utils::be32_to_array(self.best_block.height()))?;
 
-               writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
-               for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
-                       writer.write_all(&byte_utils::be32_to_array(**target))?;
-                       writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
-                       for ev in events.iter() {
-                               match *ev {
-                                       OnchainEvent::HTLCUpdate { ref htlc_update } => {
-                                               0u8.write(writer)?;
-                                               htlc_update.0.write(writer)?;
-                                               htlc_update.1.write(writer)?;
-                                       },
-                                       OnchainEvent::MaturingOutput { ref descriptor } => {
-                                               1u8.write(writer)?;
-                                               descriptor.write(writer)?;
-                                       },
-                               }
+               writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
+               for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
+                       entry.txid.write(writer)?;
+                       writer.write_all(&byte_utils::be32_to_array(entry.height))?;
+                       match entry.event {
+                               OnchainEvent::HTLCUpdate { ref htlc_update } => {
+                                       0u8.write(writer)?;
+                                       htlc_update.0.write(writer)?;
+                                       htlc_update.1.write(writer)?;
+                               },
+                               OnchainEvent::MaturingOutput { ref descriptor } => {
+                                       1u8.write(writer)?;
+                                       descriptor.write(writer)?;
+                               },
                        }
                }
 
@@ -944,17 +988,20 @@ impl<ChanSigner: ChannelKeys> Writeable for ChannelMonitor<ChanSigner> {
                self.lockdown_from_offchain.write(writer)?;
                self.holder_tx_signed.write(writer)?;
 
+               write_tlv_fields!(writer, {});
+
                Ok(())
        }
 }
 
-impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
-       pub(crate) fn new(keys: ChanSigner, shutdown_pubkey: &PublicKey,
+impl<Signer: Sign> ChannelMonitor<Signer> {
+       pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_pubkey: &PublicKey,
                          on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
                          channel_parameters: &ChannelTransactionParameters,
                          funding_redeemscript: Script, channel_value_satoshis: u64,
                          commitment_transaction_number_obscure_factor: u64,
-                         initial_holder_commitment_tx: HolderCommitmentTransaction) -> ChannelMonitor<ChanSigner> {
+                         initial_holder_commitment_tx: HolderCommitmentTransaction,
+                         best_block: BestBlock) -> ChannelMonitor<Signer> {
 
                assert!(commitment_transaction_number_obscure_factor <= (1 << 48));
                let our_channel_close_key_hash = WPubkeyHash::hash(&shutdown_pubkey.serialize());
@@ -967,11 +1014,9 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                let counterparty_htlc_base_key = counterparty_channel_parameters.pubkeys.htlc_basepoint;
                let counterparty_tx_cache = CounterpartyCommitmentTransaction { counterparty_delayed_payment_base_key, counterparty_htlc_base_key, on_counterparty_tx_csv, per_htlc: HashMap::new() };
 
-               let key_derivation_params = keys.key_derivation_params();
+               let channel_keys_id = keys.channel_keys_id();
                let holder_revocation_basepoint = keys.pubkeys().revocation_basepoint;
 
-               let secp_ctx = Secp256k1::new();
-
                // block for Rust 1.34 compat
                let (holder_commitment_tx, current_holder_commitment_number) = {
                        let trusted_tx = initial_holder_commitment_tx.trust();
@@ -992,60 +1037,361 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                };
 
                let onchain_tx_handler =
-                       OnchainTxHandler::new(destination_script.clone(), keys, channel_parameters.clone(), initial_holder_commitment_tx);
+                       OnchainTxHandler::new(destination_script.clone(), keys,
+                       channel_parameters.clone(), initial_holder_commitment_tx, secp_ctx.clone());
 
                let mut outputs_to_watch = HashMap::new();
                outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
 
                ChannelMonitor {
-                       latest_update_id: 0,
-                       commitment_transaction_number_obscure_factor,
+                       inner: Mutex::new(ChannelMonitorImpl {
+                               latest_update_id: 0,
+                               commitment_transaction_number_obscure_factor,
+
+                               destination_script: destination_script.clone(),
+                               broadcasted_holder_revokable_script: None,
+                               counterparty_payment_script,
+                               shutdown_script,
+
+                               channel_keys_id,
+                               holder_revocation_basepoint,
+                               funding_info,
+                               current_counterparty_commitment_txid: None,
+                               prev_counterparty_commitment_txid: None,
+
+                               counterparty_tx_cache,
+                               funding_redeemscript,
+                               channel_value_satoshis,
+                               their_cur_revocation_points: None,
+
+                               on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
+
+                               commitment_secrets: CounterpartyCommitmentSecrets::new(),
+                               counterparty_claimable_outpoints: HashMap::new(),
+                               counterparty_commitment_txn_on_chain: HashMap::new(),
+                               counterparty_hash_commitment_number: HashMap::new(),
+
+                               prev_holder_signed_commitment_tx: None,
+                               current_holder_commitment_tx: holder_commitment_tx,
+                               current_counterparty_commitment_number: 1 << 48,
+                               current_holder_commitment_number,
+
+                               payment_preimages: HashMap::new(),
+                               pending_monitor_events: Vec::new(),
+                               pending_events: Vec::new(),
+
+                               onchain_events_awaiting_threshold_conf: Vec::new(),
+                               outputs_to_watch,
 
-                       destination_script: destination_script.clone(),
-                       broadcasted_holder_revokable_script: None,
-                       counterparty_payment_script,
-                       shutdown_script,
+                               onchain_tx_handler,
 
-                       key_derivation_params,
-                       holder_revocation_basepoint,
-                       funding_info,
-                       current_counterparty_commitment_txid: None,
-                       prev_counterparty_commitment_txid: None,
+                               lockdown_from_offchain: false,
+                               holder_tx_signed: false,
 
-                       counterparty_tx_cache,
-                       funding_redeemscript,
-                       channel_value_satoshis,
-                       their_cur_revocation_points: None,
+                               best_block,
 
-                       on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
+                               secp_ctx,
+                       }),
+               }
+       }
+
+       #[cfg(test)]
+       fn provide_secret(&self, idx: u64, secret: [u8; 32]) -> Result<(), MonitorUpdateError> {
+               self.inner.lock().unwrap().provide_secret(idx, secret)
+       }
+
+       /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
+       /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
+       /// possibly future revocation/preimage information) to claim outputs where possible.
+       /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
+       pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(
+               &self,
+               txid: Txid,
+               htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>,
+               commitment_number: u64,
+               their_revocation_point: PublicKey,
+               logger: &L,
+       ) where L::Target: Logger {
+               self.inner.lock().unwrap().provide_latest_counterparty_commitment_tx(
+                       txid, htlc_outputs, commitment_number, their_revocation_point, logger)
+       }
+
+       #[cfg(test)]
+       fn provide_latest_holder_commitment_tx(
+               &self,
+               holder_commitment_tx: HolderCommitmentTransaction,
+               htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Signature>, Option<HTLCSource>)>,
+       ) -> Result<(), MonitorUpdateError> {
+               self.inner.lock().unwrap().provide_latest_holder_commitment_tx(
+                       holder_commitment_tx, htlc_outputs)
+       }
 
-                       commitment_secrets: CounterpartyCommitmentSecrets::new(),
-                       counterparty_claimable_outpoints: HashMap::new(),
-                       counterparty_commitment_txn_on_chain: HashMap::new(),
-                       counterparty_hash_commitment_number: HashMap::new(),
+       #[cfg(test)]
+       pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(
+               &self,
+               payment_hash: &PaymentHash,
+               payment_preimage: &PaymentPreimage,
+               broadcaster: &B,
+               fee_estimator: &F,
+               logger: &L,
+       ) where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               self.inner.lock().unwrap().provide_payment_preimage(
+                       payment_hash, payment_preimage, broadcaster, fee_estimator, logger)
+       }
 
-                       prev_holder_signed_commitment_tx: None,
-                       current_holder_commitment_tx: holder_commitment_tx,
-                       current_counterparty_commitment_number: 1 << 48,
-                       current_holder_commitment_number,
+       pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(
+               &self,
+               broadcaster: &B,
+               logger: &L,
+       ) where
+               B::Target: BroadcasterInterface,
+               L::Target: Logger,
+       {
+               self.inner.lock().unwrap().broadcast_latest_holder_commitment_txn(broadcaster, logger)
+       }
 
-                       payment_preimages: HashMap::new(),
-                       pending_monitor_events: Vec::new(),
-                       pending_events: Vec::new(),
+       /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
+       /// itself.
+       ///
+       /// panics if the given update is not the next update by update_id.
+       pub fn update_monitor<B: Deref, F: Deref, L: Deref>(
+               &self,
+               updates: &ChannelMonitorUpdate,
+               broadcaster: &B,
+               fee_estimator: &F,
+               logger: &L,
+       ) -> Result<(), MonitorUpdateError>
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               self.inner.lock().unwrap().update_monitor(updates, broadcaster, fee_estimator, logger)
+       }
 
-                       onchain_events_waiting_threshold_conf: HashMap::new(),
-                       outputs_to_watch,
+       /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
+       /// ChannelMonitor.
+       pub fn get_latest_update_id(&self) -> u64 {
+               self.inner.lock().unwrap().get_latest_update_id()
+       }
 
-                       onchain_tx_handler,
+       /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
+       pub fn get_funding_txo(&self) -> (OutPoint, Script) {
+               self.inner.lock().unwrap().get_funding_txo().clone()
+       }
 
-                       lockdown_from_offchain: false,
-                       holder_tx_signed: false,
+       /// Gets a list of txids, with their output scripts (in the order they appear in the
+       /// transaction), which we must learn about spends of via block_connected().
+       pub fn get_outputs_to_watch(&self) -> Vec<(Txid, Vec<(u32, Script)>)> {
+               self.inner.lock().unwrap().get_outputs_to_watch()
+                       .iter().map(|(txid, outputs)| (*txid, outputs.clone())).collect()
+       }
 
-                       last_block_hash: Default::default(),
-                       secp_ctx,
+       /// Loads the funding txo and outputs to watch into the given `chain::Filter` by repeatedly
+       /// calling `chain::Filter::register_output` and `chain::Filter::register_tx` until all outputs
+       /// have been registered.
+       pub fn load_outputs_to_watch<F: Deref>(&self, filter: &F) where F::Target: chain::Filter {
+               let lock = self.inner.lock().unwrap();
+               filter.register_tx(&lock.get_funding_txo().0.txid, &lock.get_funding_txo().1);
+               for (txid, outputs) in lock.get_outputs_to_watch().iter() {
+                       for (index, script_pubkey) in outputs.iter() {
+                               assert!(*index <= u16::max_value() as u32);
+                               filter.register_output(WatchedOutput {
+                                       block_hash: None,
+                                       outpoint: OutPoint { txid: *txid, index: *index as u16 },
+                                       script_pubkey: script_pubkey.clone(),
+                               });
+                       }
                }
        }
 
+       /// Get the list of HTLCs who's status has been updated on chain. This should be called by
+       /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
+       pub fn get_and_clear_pending_monitor_events(&self) -> Vec<MonitorEvent> {
+               self.inner.lock().unwrap().get_and_clear_pending_monitor_events()
+       }
+
+       /// Gets the list of pending events which were generated by previous actions, clearing the list
+       /// in the process.
+       ///
+       /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
+       /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
+       /// no internal locking in ChannelMonitors.
+       pub fn get_and_clear_pending_events(&self) -> Vec<Event> {
+               self.inner.lock().unwrap().get_and_clear_pending_events()
+       }
+
+       pub(crate) fn get_min_seen_secret(&self) -> u64 {
+               self.inner.lock().unwrap().get_min_seen_secret()
+       }
+
+       pub(crate) fn get_cur_counterparty_commitment_number(&self) -> u64 {
+               self.inner.lock().unwrap().get_cur_counterparty_commitment_number()
+       }
+
+       pub(crate) fn get_cur_holder_commitment_number(&self) -> u64 {
+               self.inner.lock().unwrap().get_cur_holder_commitment_number()
+       }
+
+       /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
+       /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
+       /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
+       /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
+       /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
+       /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
+       /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
+       /// out-of-band the other node operator to coordinate with him if option is available to you.
+       /// In any-case, choice is up to the user.
+       pub fn get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
+       where L::Target: Logger {
+               self.inner.lock().unwrap().get_latest_holder_commitment_txn(logger)
+       }
+
+       /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
+       /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
+       /// revoked commitment transaction.
+       #[cfg(any(test, feature = "unsafe_revoked_tx_signing"))]
+       pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&self, logger: &L) -> Vec<Transaction>
+       where L::Target: Logger {
+               self.inner.lock().unwrap().unsafe_get_latest_holder_commitment_txn(logger)
+       }
+
+       /// Processes transactions in a newly connected block, which may result in any of the following:
+       /// - update the monitor's state against resolved HTLCs
+       /// - punish the counterparty in the case of seeing a revoked commitment transaction
+       /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
+       /// - detect settled outputs for later spending
+       /// - schedule and bump any in-flight claims
+       ///
+       /// Returns any new outputs to watch from `txdata`; after called, these are also included in
+       /// [`get_outputs_to_watch`].
+       ///
+       /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
+       pub fn block_connected<B: Deref, F: Deref, L: Deref>(
+               &self,
+               header: &BlockHeader,
+               txdata: &TransactionData,
+               height: u32,
+               broadcaster: B,
+               fee_estimator: F,
+               logger: L,
+       ) -> Vec<TransactionOutputs>
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               self.inner.lock().unwrap().block_connected(
+                       header, txdata, height, broadcaster, fee_estimator, logger)
+       }
+
+       /// Determines if the disconnected block contained any transactions of interest and updates
+       /// appropriately.
+       pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(
+               &self,
+               header: &BlockHeader,
+               height: u32,
+               broadcaster: B,
+               fee_estimator: F,
+               logger: L,
+       ) where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               self.inner.lock().unwrap().block_disconnected(
+                       header, height, broadcaster, fee_estimator, logger)
+       }
+
+       /// Processes transactions confirmed in a block with the given header and height, returning new
+       /// outputs to watch. See [`block_connected`] for details.
+       ///
+       /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
+       /// blocks. See [`chain::Confirm`] for calling expectations.
+       ///
+       /// [`block_connected`]: Self::block_connected
+       pub fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
+               &self,
+               header: &BlockHeader,
+               txdata: &TransactionData,
+               height: u32,
+               broadcaster: B,
+               fee_estimator: F,
+               logger: L,
+       ) -> Vec<TransactionOutputs>
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               self.inner.lock().unwrap().transactions_confirmed(
+                       header, txdata, height, broadcaster, fee_estimator, logger)
+       }
+
+       /// Processes a transaction that was reorganized out of the chain.
+       ///
+       /// Used instead of [`block_disconnected`] by clients that are notified of transactions rather
+       /// than blocks. See [`chain::Confirm`] for calling expectations.
+       ///
+       /// [`block_disconnected`]: Self::block_disconnected
+       pub fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
+               &self,
+               txid: &Txid,
+               broadcaster: B,
+               fee_estimator: F,
+               logger: L,
+       ) where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               self.inner.lock().unwrap().transaction_unconfirmed(
+                       txid, broadcaster, fee_estimator, logger);
+       }
+
+       /// Updates the monitor with the current best chain tip, returning new outputs to watch. See
+       /// [`block_connected`] for details.
+       ///
+       /// Used instead of [`block_connected`] by clients that are notified of transactions rather than
+       /// blocks. See [`chain::Confirm`] for calling expectations.
+       ///
+       /// [`block_connected`]: Self::block_connected
+       pub fn best_block_updated<B: Deref, F: Deref, L: Deref>(
+               &self,
+               header: &BlockHeader,
+               height: u32,
+               broadcaster: B,
+               fee_estimator: F,
+               logger: L,
+       ) -> Vec<TransactionOutputs>
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               self.inner.lock().unwrap().best_block_updated(
+                       header, height, broadcaster, fee_estimator, logger)
+       }
+
+       /// Returns the set of txids that should be monitored for re-organization out of the chain.
+       pub fn get_relevant_txids(&self) -> Vec<Txid> {
+               let inner = self.inner.lock().unwrap();
+               let mut txids: Vec<Txid> = inner.onchain_events_awaiting_threshold_conf
+                       .iter()
+                       .map(|entry| entry.txid)
+                       .chain(inner.onchain_tx_handler.get_relevant_txids().into_iter())
+                       .collect();
+               txids.sort_unstable();
+               txids.dedup();
+               txids
+       }
+}
+
+impl<Signer: Sign> ChannelMonitorImpl<Signer> {
        /// Inserts a revocation secret into this channel monitor. Prunes old preimages if neither
        /// needed by holder commitment transactions HTCLs nor by counterparty ones. Unless we haven't already seen
        /// counterparty commitment transaction's secret, they are de facto pruned (we can use revocation key).
@@ -1097,10 +1443,6 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                Ok(())
        }
 
-       /// Informs this monitor of the latest counterparty (ie non-broadcastable) commitment transaction.
-       /// The monitor watches for it to be broadcasted and then uses the HTLC information (and
-       /// possibly future revocation/preimage information) to claim outputs where possible.
-       /// We cache also the mapping hash:commitment number to lighten pruning of old preimages by watchtowers.
        pub(crate) fn provide_latest_counterparty_commitment_tx<L: Deref>(&mut self, txid: Txid, htlc_outputs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)>, commitment_number: u64, their_revocation_point: PublicKey, logger: &L) where L::Target: Logger {
                // TODO: Encrypt the htlc_outputs data with the single-hash of the commitment transaction
                // so that a remote monitor doesn't learn anything unless there is a malicious close.
@@ -1177,7 +1519,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 
        /// Provides a payment_hash->payment_preimage mapping. Will be automatically pruned when all
        /// commitment_tx_infos which contain the payment hash have been revoked.
-       pub(crate) fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B, fee_estimator: &F, logger: &L)
+       fn provide_payment_preimage<B: Deref, F: Deref, L: Deref>(&mut self, payment_hash: &PaymentHash, payment_preimage: &PaymentPreimage, broadcaster: &B, fee_estimator: &F, logger: &L)
        where B::Target: BroadcasterInterface,
                    F::Target: FeeEstimator,
                    L::Target: Logger,
@@ -1225,15 +1567,12 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                        L::Target: Logger,
        {
                for tx in self.get_latest_holder_commitment_txn(logger).iter() {
+                       log_info!(logger, "Broadcasting local {}", log_tx!(tx));
                        broadcaster.broadcast_transaction(tx);
                }
                self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
        }
 
-       /// Updates a ChannelMonitor on the basis of some new information provided by the Channel
-       /// itself.
-       ///
-       /// panics if the given update is not the next update by update_id.
        pub fn update_monitor<B: Deref, F: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, fee_estimator: &F, logger: &L) -> Result<(), MonitorUpdateError>
        where B::Target: BroadcasterInterface,
                    F::Target: FeeEstimator,
@@ -1276,8 +1615,13 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                        self.lockdown_from_offchain = true;
                                        if *should_broadcast {
                                                self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
-                                       } else {
+                                       } else if !self.holder_tx_signed {
                                                log_error!(logger, "You have a toxic holder commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_holder_commitment_txn to be informed of manual action to take");
+                                       } else {
+                                               // If we generated a MonitorEvent::CommitmentTxBroadcasted, the ChannelManager
+                                               // will still give us a ChannelForceClosed event with !should_broadcast, but we
+                                               // shouldn't print the scary warning above.
+                                               log_info!(logger, "Channel off-chain state closed after we broadcasted our latest commitment transaction.");
                                        }
                                }
                        }
@@ -1286,21 +1630,14 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                Ok(())
        }
 
-       /// Gets the update_id from the latest ChannelMonitorUpdate which was applied to this
-       /// ChannelMonitor.
        pub fn get_latest_update_id(&self) -> u64 {
                self.latest_update_id
        }
 
-       /// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
        pub fn get_funding_txo(&self) -> &(OutPoint, Script) {
                &self.funding_info
        }
 
-       /// Gets a list of txids, with their output scripts (in the order they appear in the
-       /// transaction), which we must learn about spends of via block_connected().
-       ///
-       /// (C-not exported) because we have no HashMap bindings
        pub fn get_outputs_to_watch(&self) -> &HashMap<Txid, Vec<(u32, Script)>> {
                // If we've detected a counterparty commitment tx on chain, we must include it in the set
                // of outputs to watch for spends of, otherwise we're likely to lose user funds. Because
@@ -1311,22 +1648,12 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                &self.outputs_to_watch
        }
 
-       /// Get the list of HTLCs who's status has been updated on chain. This should be called by
-       /// ChannelManager via [`chain::Watch::release_pending_monitor_events`].
-       ///
-       /// [`chain::Watch::release_pending_monitor_events`]: ../trait.Watch.html#tymethod.release_pending_monitor_events
        pub fn get_and_clear_pending_monitor_events(&mut self) -> Vec<MonitorEvent> {
                let mut ret = Vec::new();
                mem::swap(&mut ret, &mut self.pending_monitor_events);
                ret
        }
 
-       /// Gets the list of pending events which were generated by previous actions, clearing the list
-       /// in the process.
-       ///
-       /// This is called by ChainMonitor::get_and_clear_pending_events() and is equivalent to
-       /// EventsProvider::get_and_clear_pending_events() except that it requires &mut self as we do
-       /// no internal locking in ChannelMonitors.
        pub fn get_and_clear_pending_events(&mut self) -> Vec<Event> {
                let mut ret = Vec::new();
                mem::swap(&mut ret, &mut self.pending_events);
@@ -1356,7 +1683,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        /// HTLC-Success/HTLC-Timeout transactions.
        /// Return updates for HTLC pending in the channel and failed automatically by the broadcast of
        /// revoked counterparty commitment tx
-       fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<(u32, TxOut)>)) where L::Target: Logger {
+       fn check_spend_counterparty_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, TransactionOutputs) where L::Target: Logger {
                // Most secp and related errors trying to create keys means we have no hope of constructing
                // a spend transaction...so we return no transactions to broadcast
                let mut claimable_outpoints = Vec::new();
@@ -1421,24 +1748,24 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                                if let Some(ref outpoints) = self.counterparty_claimable_outpoints.get($txid) {
                                                        for &(ref htlc, ref source_option) in outpoints.iter() {
                                                                if let &Some(ref source) = source_option {
-                                                                       log_info!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of revoked counterparty commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
-                                                                       match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
-                                                                               hash_map::Entry::Occupied(mut entry) => {
-                                                                                       let e = entry.get_mut();
-                                                                                       e.retain(|ref event| {
-                                                                                               match **event {
-                                                                                                       OnchainEvent::HTLCUpdate { ref htlc_update } => {
-                                                                                                               return htlc_update.0 != **source
-                                                                                                       },
-                                                                                                       _ => true
-                                                                                               }
-                                                                                       });
-                                                                                       e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
+                                                                       self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
+                                                                               if entry.height != height { return true; }
+                                                                               match entry.event {
+                                                                                        OnchainEvent::HTLCUpdate { ref htlc_update } => {
+                                                                                                htlc_update.0 != **source
+                                                                                        },
+                                                                                        _ => true,
                                                                                }
-                                                                               hash_map::Entry::Vacant(entry) => {
-                                                                                       entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
-                                                                               }
-                                                                       }
+                                                                       });
+                                                                       let entry = OnchainEventEntry {
+                                                                               txid: *$txid,
+                                                                               height,
+                                                                               event: OnchainEvent::HTLCUpdate {
+                                                                                       htlc_update: ((**source).clone(), htlc.payment_hash.clone())
+                                                                               },
+                                                                       };
+                                                                       log_info!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of revoked counterparty commitment transaction, waiting for confirmation (at height {})", log_bytes!(htlc.payment_hash.0), $commitment_tx, entry.confirmation_threshold());
+                                                                       self.onchain_events_awaiting_threshold_conf.push(entry);
                                                                }
                                                        }
                                                }
@@ -1487,23 +1814,22 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                                                        }
                                                                }
                                                                log_trace!(logger, "Failing HTLC with payment_hash {} from {} counterparty commitment tx due to broadcast of counterparty commitment transaction", log_bytes!(htlc.payment_hash.0), $commitment_tx);
-                                                               match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
-                                                                       hash_map::Entry::Occupied(mut entry) => {
-                                                                               let e = entry.get_mut();
-                                                                               e.retain(|ref event| {
-                                                                                       match **event {
-                                                                                               OnchainEvent::HTLCUpdate { ref htlc_update } => {
-                                                                                                       return htlc_update.0 != **source
-                                                                                               },
-                                                                                               _ => true
-                                                                                       }
-                                                                               });
-                                                                               e.push(OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())});
-                                                                       }
-                                                                       hash_map::Entry::Vacant(entry) => {
-                                                                               entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ((**source).clone(), htlc.payment_hash.clone())}]);
+                                                               self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
+                                                                       if entry.height != height { return true; }
+                                                                       match entry.event {
+                                                                                OnchainEvent::HTLCUpdate { ref htlc_update } => {
+                                                                                        htlc_update.0 != **source
+                                                                                },
+                                                                                _ => true,
                                                                        }
-                                                               }
+                                                               });
+                                                               self.onchain_events_awaiting_threshold_conf.push(OnchainEventEntry {
+                                                                       txid: *$txid,
+                                                                       height,
+                                                                       event: OnchainEvent::HTLCUpdate {
+                                                                               htlc_update: ((**source).clone(), htlc.payment_hash.clone())
+                                                                       },
+                                                               });
                                                        }
                                                }
                                        }
@@ -1568,7 +1894,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        }
 
        /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
-       fn check_spend_counterparty_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<ClaimRequest>, Option<(Txid, Vec<(u32, TxOut)>)>) where L::Target: Logger {
+       fn check_spend_counterparty_htlc<L: Deref>(&mut self, tx: &Transaction, commitment_number: u64, height: u32, logger: &L) -> (Vec<ClaimRequest>, Option<TransactionOutputs>) where L::Target: Logger {
                let htlc_txid = tx.txid();
                if tx.input.len() != 1 || tx.output.len() != 1 || tx.input[0].witness.len() != 5 {
                        return (Vec::new(), None)
@@ -1605,7 +1931,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 
                for &(ref htlc, _, _) in holder_tx.htlc_outputs.iter() {
                        if let Some(transaction_output_index) = htlc.transaction_output_index {
-                               claim_requests.push(ClaimRequest { absolute_timelock: ::std::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
+                               claim_requests.push(ClaimRequest { absolute_timelock: ::core::u32::MAX, aggregable: false, outpoint: BitcoinOutPoint { txid: holder_tx.txid, vout: transaction_output_index as u32 },
                                        witness_data: InputMaterial::HolderHTLC {
                                                preimage: if !htlc.offered {
                                                                if let Some(preimage) = self.payment_preimages.get(&htlc.payment_hash) {
@@ -1637,31 +1963,29 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        /// Attempts to claim any claimable HTLCs in a commitment transaction which was not (yet)
        /// revoked using data in holder_claimable_outpoints.
        /// Should not be used if check_spend_revoked_transaction succeeds.
-       fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, (Txid, Vec<(u32, TxOut)>)) where L::Target: Logger {
+       fn check_spend_holder_transaction<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) -> (Vec<ClaimRequest>, TransactionOutputs) where L::Target: Logger {
                let commitment_txid = tx.txid();
                let mut claim_requests = Vec::new();
                let mut watch_outputs = Vec::new();
 
                macro_rules! wait_threshold_conf {
-                       ($height: expr, $source: expr, $commitment_tx: expr, $payment_hash: expr) => {
-                               log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, height + ANTI_REORG_DELAY - 1);
-                               match self.onchain_events_waiting_threshold_conf.entry($height + ANTI_REORG_DELAY - 1) {
-                                       hash_map::Entry::Occupied(mut entry) => {
-                                               let e = entry.get_mut();
-                                               e.retain(|ref event| {
-                                                       match **event {
-                                                               OnchainEvent::HTLCUpdate { ref htlc_update } => {
-                                                                       return htlc_update.0 != $source
-                                                               },
-                                                               _ => true
-                                                       }
-                                               });
-                                               e.push(OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)});
-                                       }
-                                       hash_map::Entry::Vacant(entry) => {
-                                               entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash)}]);
+                       ($source: expr, $commitment_tx: expr, $payment_hash: expr) => {
+                               self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
+                                       if entry.height != height { return true; }
+                                       match entry.event {
+                                                OnchainEvent::HTLCUpdate { ref htlc_update } => {
+                                                        htlc_update.0 != $source
+                                                },
+                                                _ => true,
                                        }
-                               }
+                               });
+                               let entry = OnchainEventEntry {
+                                       txid: commitment_txid,
+                                       height,
+                                       event: OnchainEvent::HTLCUpdate { htlc_update: ($source, $payment_hash) },
+                               };
+                               log_trace!(logger, "Failing HTLC with payment_hash {} from {} holder commitment tx due to broadcast of transaction, waiting confirmation (at height{})", log_bytes!($payment_hash.0), $commitment_tx, entry.confirmation_threshold());
+                               self.onchain_events_awaiting_threshold_conf.push(entry);
                        }
                }
 
@@ -1697,7 +2021,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                for &(ref htlc, _, ref source) in &$holder_tx.htlc_outputs {
                                        if htlc.transaction_output_index.is_none() {
                                                if let &Some(ref source) = source {
-                                                       wait_threshold_conf!(height, source.clone(), "lastest", htlc.payment_hash.clone());
+                                                       wait_threshold_conf!(source.clone(), "lastest", htlc.payment_hash.clone());
                                                }
                                        }
                                }
@@ -1714,15 +2038,6 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                (claim_requests, (commitment_txid, watch_outputs))
        }
 
-       /// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
-       /// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
-       /// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows
-       /// a higher revocation secret than the holder commitment number we are aware of. Broadcasting these
-       /// transactions are UNSAFE, as they allow counterparty side to punish you. Nevertheless you may want to
-       /// broadcast them if counterparty don't close channel with his higher commitment transaction after a
-       /// substantial amount of time (a month or even a year) to get back funds. Best may be to contact
-       /// out-of-band the other node operator to coordinate with him if option is available to you.
-       /// In any-case, choice is up to the user.
        pub fn get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
                log_trace!(logger, "Getting signed latest holder commitment transaction!");
                self.holder_tx_signed = true;
@@ -1748,11 +2063,8 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                return res;
        }
 
-       /// Unsafe test-only version of get_latest_holder_commitment_txn used by our test framework
-       /// to bypass HolderCommitmentTransaction state update lockdown after signature and generate
-       /// revoked commitment transaction.
        #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
-       pub fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
+       fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
                log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
                let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
                let txid = commitment_tx.txid();
@@ -1774,21 +2086,58 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                return res
        }
 
-       /// Processes transactions in a newly connected block, which may result in any of the following:
-       /// - update the monitor's state against resolved HTLCs
-       /// - punish the counterparty in the case of seeing a revoked commitment transaction
-       /// - force close the channel and claim/timeout incoming/outgoing HTLCs if near expiration
-       /// - detect settled outputs for later spending
-       /// - schedule and bump any in-flight claims
-       ///
-       /// Returns any new outputs to watch from `txdata`; after called, these are also included in
-       /// [`get_outputs_to_watch`].
-       ///
-       /// [`get_outputs_to_watch`]: #method.get_outputs_to_watch
-       pub fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, txdata: &TransactionData, height: u32, broadcaster: B, fee_estimator: F, logger: L)-> Vec<(Txid, Vec<(u32, TxOut)>)>
+       pub fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, txdata: &TransactionData, height: u32, broadcaster: B, fee_estimator: F, logger: L) -> Vec<TransactionOutputs>
                where B::Target: BroadcasterInterface,
                      F::Target: FeeEstimator,
                                        L::Target: Logger,
+       {
+               let block_hash = header.block_hash();
+               log_trace!(logger, "New best block {} at height {}", block_hash, height);
+               self.best_block = BestBlock::new(block_hash, height);
+
+               self.transactions_confirmed(header, txdata, height, broadcaster, fee_estimator, logger)
+       }
+
+       fn best_block_updated<B: Deref, F: Deref, L: Deref>(
+               &mut self,
+               header: &BlockHeader,
+               height: u32,
+               broadcaster: B,
+               fee_estimator: F,
+               logger: L,
+       ) -> Vec<TransactionOutputs>
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               let block_hash = header.block_hash();
+               log_trace!(logger, "New best block {} at height {}", block_hash, height);
+
+               if height > self.best_block.height() {
+                       self.best_block = BestBlock::new(block_hash, height);
+                       self.block_confirmed(height, vec![], vec![], vec![], broadcaster, fee_estimator, logger)
+               } else {
+                       self.best_block = BestBlock::new(block_hash, height);
+                       self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height <= height);
+                       self.onchain_tx_handler.block_disconnected(height + 1, broadcaster, fee_estimator, logger);
+                       Vec::new()
+               }
+       }
+
+       fn transactions_confirmed<B: Deref, F: Deref, L: Deref>(
+               &mut self,
+               header: &BlockHeader,
+               txdata: &TransactionData,
+               height: u32,
+               broadcaster: B,
+               fee_estimator: F,
+               logger: L,
+       ) -> Vec<TransactionOutputs>
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
        {
                let txn_matched = self.filter_block(txdata);
                for tx in &txn_matched {
@@ -1844,11 +2193,28 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 
                        self.is_paying_spendable_output(&tx, height, &logger);
                }
+
+               self.block_confirmed(height, txn_matched, watch_outputs, claimable_outpoints, broadcaster, fee_estimator, logger)
+       }
+
+       fn block_confirmed<B: Deref, F: Deref, L: Deref>(
+               &mut self,
+               height: u32,
+               txn_matched: Vec<&Transaction>,
+               mut watch_outputs: Vec<TransactionOutputs>,
+               mut claimable_outpoints: Vec<ClaimRequest>,
+               broadcaster: B,
+               fee_estimator: F,
+               logger: L,
+       ) -> Vec<TransactionOutputs>
+       where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
                let should_broadcast = self.would_broadcast_at_height(height, &logger);
                if should_broadcast {
                        claimable_outpoints.push(ClaimRequest { absolute_timelock: height, aggregable: false, outpoint: BitcoinOutPoint { txid: self.funding_info.0.txid.clone(), vout: self.funding_info.0.index as u32 }, witness_data: InputMaterial::Funding { funding_redeemscript: self.funding_redeemscript.clone() }});
-               }
-               if should_broadcast {
                        self.pending_monitor_events.push(MonitorEvent::CommitmentTxBroadcasted(self.funding_info.0));
                        let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
                        self.holder_tx_signed = true;
@@ -1859,29 +2225,68 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        }
                        claimable_outpoints.append(&mut new_outpoints);
                }
-               if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
-                       for ev in events {
-                               match ev {
-                                       OnchainEvent::HTLCUpdate { htlc_update } => {
-                                               log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
-                                               self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
-                                                       payment_hash: htlc_update.1,
-                                                       payment_preimage: None,
-                                                       source: htlc_update.0,
-                                               }));
-                                       },
-                                       OnchainEvent::MaturingOutput { descriptor } => {
-                                               log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
-                                               self.pending_events.push(Event::SpendableOutputs {
-                                                       outputs: vec![descriptor]
-                                               });
+
+               // Find which on-chain events have reached their confirmation threshold.
+               let onchain_events_awaiting_threshold_conf =
+                       self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
+               let mut onchain_events_reaching_threshold_conf = Vec::new();
+               for entry in onchain_events_awaiting_threshold_conf {
+                       if entry.has_reached_confirmation_threshold(height) {
+                               onchain_events_reaching_threshold_conf.push(entry);
+                       } else {
+                               self.onchain_events_awaiting_threshold_conf.push(entry);
+                       }
+               }
+
+               // Used to check for duplicate HTLC resolutions.
+               #[cfg(debug_assertions)]
+               let unmatured_htlcs: Vec<_> = self.onchain_events_awaiting_threshold_conf
+                       .iter()
+                       .filter_map(|entry| match &entry.event {
+                               OnchainEvent::HTLCUpdate { htlc_update } => Some(htlc_update.0.clone()),
+                               OnchainEvent::MaturingOutput { .. } => None,
+                       })
+                       .collect();
+               #[cfg(debug_assertions)]
+               let mut matured_htlcs = Vec::new();
+
+               // Produce actionable events from on-chain events having reached their threshold.
+               for entry in onchain_events_reaching_threshold_conf.drain(..) {
+                       match entry.event {
+                               OnchainEvent::HTLCUpdate { htlc_update } => {
+                                       // Check for duplicate HTLC resolutions.
+                                       #[cfg(debug_assertions)]
+                                       {
+                                               debug_assert!(
+                                                       unmatured_htlcs.iter().find(|&htlc| htlc == &htlc_update.0).is_none(),
+                                                       "An unmature HTLC transaction conflicts with a maturing one; failed to \
+                                                        call either transaction_unconfirmed for the conflicting transaction \
+                                                        or block_disconnected for a block containing it.");
+                                               debug_assert!(
+                                                       matured_htlcs.iter().find(|&htlc| htlc == &htlc_update.0).is_none(),
+                                                       "A matured HTLC transaction conflicts with a maturing one; failed to \
+                                                        call either transaction_unconfirmed for the conflicting transaction \
+                                                        or block_disconnected for a block containing it.");
+                                               matured_htlcs.push(htlc_update.0.clone());
                                        }
+
+                                       log_trace!(logger, "HTLC {} failure update has got enough confirmations to be passed upstream", log_bytes!((htlc_update.1).0));
+                                       self.pending_monitor_events.push(MonitorEvent::HTLCEvent(HTLCUpdate {
+                                               payment_hash: htlc_update.1,
+                                               payment_preimage: None,
+                                               source: htlc_update.0,
+                                       }));
+                               },
+                               OnchainEvent::MaturingOutput { descriptor } => {
+                                       log_trace!(logger, "Descriptor {} has got enough confirmations to be passed upstream", log_spendable!(descriptor));
+                                       self.pending_events.push(Event::SpendableOutputs {
+                                               outputs: vec![descriptor]
+                                       });
                                }
                        }
                }
 
                self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, Some(height), &&*broadcaster, &&*fee_estimator, &&*logger);
-               self.last_block_hash = block_hash;
 
                // Determine new outputs to watch by comparing against previously known outputs to watch,
                // updating the latter in the process.
@@ -1906,25 +2311,36 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                watch_outputs
        }
 
-       /// Determines if the disconnected block contained any transactions of interest and updates
-       /// appropriately.
        pub fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, height: u32, broadcaster: B, fee_estimator: F, logger: L)
                where B::Target: BroadcasterInterface,
                      F::Target: FeeEstimator,
                      L::Target: Logger,
        {
-               let block_hash = header.block_hash();
-               log_trace!(logger, "Block {} at height {} disconnected", block_hash, height);
+               log_trace!(logger, "Block {} at height {} disconnected", header.block_hash(), height);
 
-               if let Some(_) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
-                       //We may discard:
-                       //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
-                       //- maturing spendable output has transaction paying us has been disconnected
-               }
+               //We may discard:
+               //- htlc update there as failure-trigger tx (revoked commitment tx, non-revoked commitment tx, HTLC-timeout tx) has been disconnected
+               //- maturing spendable output has transaction paying us has been disconnected
+               self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.height < height);
 
                self.onchain_tx_handler.block_disconnected(height, broadcaster, fee_estimator, logger);
 
-               self.last_block_hash = block_hash;
+               self.best_block = BestBlock::new(header.prev_blockhash, height - 1);
+       }
+
+       fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
+               &mut self,
+               txid: &Txid,
+               broadcaster: B,
+               fee_estimator: F,
+               logger: L,
+       ) where
+               B::Target: BroadcasterInterface,
+               F::Target: FeeEstimator,
+               L::Target: Logger,
+       {
+               self.onchain_events_awaiting_threshold_conf.retain(|ref entry| entry.txid != *txid);
+               self.onchain_tx_handler.transaction_unconfirmed(txid, broadcaster, fee_estimator, logger);
        }
 
        /// Filters a block's `txdata` for transactions spending watched outputs or for any child
@@ -2152,24 +2568,22 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                                }));
                                        }
                                } else {
-                                       log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height{})", log_bytes!(payment_hash.0), height + ANTI_REORG_DELAY - 1);
-                                       match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
-                                               hash_map::Entry::Occupied(mut entry) => {
-                                                       let e = entry.get_mut();
-                                                       e.retain(|ref event| {
-                                                               match **event {
-                                                                       OnchainEvent::HTLCUpdate { ref htlc_update } => {
-                                                                               return htlc_update.0 != source
-                                                                       },
-                                                                       _ => true
-                                                               }
-                                                       });
-                                                       e.push(OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)});
+                                       self.onchain_events_awaiting_threshold_conf.retain(|ref entry| {
+                                               if entry.height != height { return true; }
+                                               match entry.event {
+                                                        OnchainEvent::HTLCUpdate { ref htlc_update } => {
+                                                                htlc_update.0 != source
+                                                        },
+                                                        _ => true,
                                                }
-                                               hash_map::Entry::Vacant(entry) => {
-                                                       entry.insert(vec![OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash)}]);
-                                               }
-                                       }
+                                       });
+                                       let entry = OnchainEventEntry {
+                                               txid: tx.txid(),
+                                               height,
+                                               event: OnchainEvent::HTLCUpdate { htlc_update: (source, payment_hash) },
+                                       };
+                                       log_info!(logger, "Failing HTLC with payment_hash {} timeout by a spend tx, waiting for confirmation (at height{})", log_bytes!(payment_hash.0), entry.confirmation_threshold());
+                                       self.onchain_events_awaiting_threshold_conf.push(entry);
                                }
                        }
                }
@@ -2179,7 +2593,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
        fn is_paying_spendable_output<L: Deref>(&mut self, tx: &Transaction, height: u32, logger: &L) where L::Target: Logger {
                let mut spendable_output = None;
                for (i, outp) in tx.output.iter().enumerate() { // There is max one spendable output for any channel tx, including ones generated by us
-                       if i > ::std::u16::MAX as usize {
+                       if i > ::core::u16::MAX as usize {
                                // While it is possible that an output exists on chain which is greater than the
                                // 2^16th output in a given transaction, this is only possible if the output is not
                                // in a lightning transaction and was instead placed there by some third party who
@@ -2201,22 +2615,24 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                break;
                        } else if let Some(ref broadcasted_holder_revokable_script) = self.broadcasted_holder_revokable_script {
                                if broadcasted_holder_revokable_script.0 == outp.script_pubkey {
-                                       spendable_output =  Some(SpendableOutputDescriptor::DynamicOutputP2WSH {
+                                       spendable_output =  Some(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
                                                outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
                                                per_commitment_point: broadcasted_holder_revokable_script.1,
                                                to_self_delay: self.on_holder_tx_csv,
                                                output: outp.clone(),
-                                               key_derivation_params: self.key_derivation_params,
                                                revocation_pubkey: broadcasted_holder_revokable_script.2.clone(),
-                                       });
+                                               channel_keys_id: self.channel_keys_id,
+                                               channel_value_satoshis: self.channel_value_satoshis,
+                                       }));
                                        break;
                                }
                        } else if self.counterparty_payment_script == outp.script_pubkey {
-                               spendable_output = Some(SpendableOutputDescriptor::StaticOutputCounterpartyPayment {
+                               spendable_output = Some(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
                                        outpoint: OutPoint { txid: tx.txid(), index: i as u16 },
                                        output: outp.clone(),
-                                       key_derivation_params: self.key_derivation_params,
-                               });
+                                       channel_keys_id: self.channel_keys_id,
+                                       channel_value_satoshis: self.channel_value_satoshis,
+                               }));
                                break;
                        } else if outp.script_pubkey == self.shutdown_script {
                                spendable_output = Some(SpendableOutputDescriptor::StaticOutput {
@@ -2226,16 +2642,13 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        }
                }
                if let Some(spendable_output) = spendable_output {
-                       log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), height + ANTI_REORG_DELAY - 1);
-                       match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
-                               hash_map::Entry::Occupied(mut entry) => {
-                                       let e = entry.get_mut();
-                                       e.push(OnchainEvent::MaturingOutput { descriptor: spendable_output });
-                               }
-                               hash_map::Entry::Vacant(entry) => {
-                                       entry.insert(vec![OnchainEvent::MaturingOutput { descriptor: spendable_output }]);
-                               }
-                       }
+                       let entry = OnchainEventEntry {
+                               txid: tx.txid(),
+                               height: height,
+                               event: OnchainEvent::MaturingOutput { descriptor: spendable_output.clone() },
+                       };
+                       log_trace!(logger, "Maturing {} until {}", log_spendable!(spendable_output), entry.confirmation_threshold());
+                       self.onchain_events_awaiting_threshold_conf.push(entry);
                }
        }
 }
@@ -2251,19 +2664,16 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 /// transaction and losing money. This is a risk because previous channel states
 /// are toxic, so it's important that whatever channel state is persisted is
 /// kept up-to-date.
-pub trait Persist<Keys: ChannelKeys>: Send + Sync {
+pub trait Persist<ChannelSigner: Sign> {
        /// Persist a new channel's data. The data can be stored any way you want, but
        /// the identifier provided by Rust-Lightning is the channel's outpoint (and
        /// it is up to you to maintain a correct mapping between the outpoint and the
        /// stored channel data). Note that you **must** persist every new monitor to
        /// disk. See the `Persist` trait documentation for more details.
        ///
-       /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
+       /// See [`ChannelMonitor::write`] for writing out a `ChannelMonitor`,
        /// and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
-       ///
-       /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
-       /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
-       fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
+       fn persist_new_channel(&self, id: OutPoint, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
 
        /// Update one channel's data. The provided `ChannelMonitor` has already
        /// applied the given update.
@@ -2284,21 +2694,55 @@ pub trait Persist<Keys: ChannelKeys>: Send + Sync {
        /// them in batches. The size of each monitor grows `O(number of state updates)`
        /// whereas updates are small and `O(1)`.
        ///
-       /// See [`ChannelMonitor::serialize_for_disk`] for writing out a `ChannelMonitor`,
+       /// See [`ChannelMonitor::write`] for writing out a `ChannelMonitor`,
        /// [`ChannelMonitorUpdate::write`] for writing out an update, and
        /// [`ChannelMonitorUpdateErr`] for requirements when returning errors.
-       ///
-       /// [`ChannelMonitor::update_monitor`]: struct.ChannelMonitor.html#impl-1
-       /// [`ChannelMonitor::serialize_for_disk`]: struct.ChannelMonitor.html#method.serialize_for_disk
-       /// [`ChannelMonitorUpdate::write`]: struct.ChannelMonitorUpdate.html#method.write
-       /// [`ChannelMonitorUpdateErr`]: enum.ChannelMonitorUpdateErr.html
-       fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<Keys>) -> Result<(), ChannelMonitorUpdateErr>;
+       fn update_persisted_channel(&self, id: OutPoint, update: &ChannelMonitorUpdate, data: &ChannelMonitor<ChannelSigner>) -> Result<(), ChannelMonitorUpdateErr>;
+}
+
+impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Listen for (ChannelMonitor<Signer>, T, F, L)
+where
+       T::Target: BroadcasterInterface,
+       F::Target: FeeEstimator,
+       L::Target: Logger,
+{
+       fn block_connected(&self, block: &Block, height: u32) {
+               let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
+               self.0.block_connected(&block.header, &txdata, height, &*self.1, &*self.2, &*self.3);
+       }
+
+       fn block_disconnected(&self, header: &BlockHeader, height: u32) {
+               self.0.block_disconnected(header, height, &*self.1, &*self.2, &*self.3);
+       }
+}
+
+impl<Signer: Sign, T: Deref, F: Deref, L: Deref> chain::Confirm for (ChannelMonitor<Signer>, T, F, L)
+where
+       T::Target: BroadcasterInterface,
+       F::Target: FeeEstimator,
+       L::Target: Logger,
+{
+       fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
+               self.0.transactions_confirmed(header, txdata, height, &*self.1, &*self.2, &*self.3);
+       }
+
+       fn transaction_unconfirmed(&self, txid: &Txid) {
+               self.0.transaction_unconfirmed(txid, &*self.1, &*self.2, &*self.3);
+       }
+
+       fn best_block_updated(&self, header: &BlockHeader, height: u32) {
+               self.0.best_block_updated(header, height, &*self.1, &*self.2, &*self.3);
+       }
+
+       fn get_relevant_txids(&self) -> Vec<Txid> {
+               self.0.get_relevant_txids()
+       }
 }
 
 const MAX_ALLOC_SIZE: usize = 64*1024;
 
-impl<'a, ChanSigner: ChannelKeys, K: KeysInterface<ChanKeySigner = ChanSigner>> ReadableArgs<&'a K>
-               for (BlockHash, ChannelMonitor<ChanSigner>) {
+impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
+               for (BlockHash, ChannelMonitor<Signer>) {
        fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
                macro_rules! unwrap_obj {
                        ($key: expr) => {
@@ -2309,11 +2753,7 @@ impl<'a, ChanSigner: ChannelKeys, K: KeysInterface<ChanKeySigner = ChanSigner>>
                        }
                }
 
-               let _ver: u8 = Readable::read(reader)?;
-               let min_ver: u8 = Readable::read(reader)?;
-               if min_ver > SERIALIZATION_VERSION {
-                       return Err(DecodeError::UnknownVersion);
-               }
+               let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 
                let latest_update_id: u64 = Readable::read(reader)?;
                let commitment_transaction_number_obscure_factor = <U48 as Readable>::read(reader)?.0;
@@ -2332,7 +2772,7 @@ impl<'a, ChanSigner: ChannelKeys, K: KeysInterface<ChanKeySigner = ChanSigner>>
                let counterparty_payment_script = Readable::read(reader)?;
                let shutdown_script = Readable::read(reader)?;
 
-               let key_derivation_params = Readable::read(reader)?;
+               let channel_keys_id = Readable::read(reader)?;
                let holder_revocation_basepoint = Readable::read(reader)?;
                // Technically this can fail and serialize fail a round-trip, but only for serialization of
                // barely-init'd ChannelMonitors that we can't do anything with.
@@ -2490,34 +2930,30 @@ impl<'a, ChanSigner: ChannelKeys, K: KeysInterface<ChanKeySigner = ChanSigner>>
                        }
                }
 
-               let last_block_hash: BlockHash = Readable::read(reader)?;
+               let best_block = BestBlock::new(Readable::read(reader)?, Readable::read(reader)?);
 
                let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
-               let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
+               let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
                for _ in 0..waiting_threshold_conf_len {
-                       let height_target = Readable::read(reader)?;
-                       let events_len: u64 = Readable::read(reader)?;
-                       let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
-                       for _ in 0..events_len {
-                               let ev = match <u8 as Readable>::read(reader)? {
-                                       0 => {
-                                               let htlc_source = Readable::read(reader)?;
-                                               let hash = Readable::read(reader)?;
-                                               OnchainEvent::HTLCUpdate {
-                                                       htlc_update: (htlc_source, hash)
-                                               }
-                                       },
-                                       1 => {
-                                               let descriptor = Readable::read(reader)?;
-                                               OnchainEvent::MaturingOutput {
-                                                       descriptor
-                                               }
-                                       },
-                                       _ => return Err(DecodeError::InvalidValue),
-                               };
-                               events.push(ev);
-                       }
-                       onchain_events_waiting_threshold_conf.insert(height_target, events);
+                       let txid = Readable::read(reader)?;
+                       let height = Readable::read(reader)?;
+                       let event = match <u8 as Readable>::read(reader)? {
+                               0 => {
+                                       let htlc_source = Readable::read(reader)?;
+                                       let hash = Readable::read(reader)?;
+                                       OnchainEvent::HTLCUpdate {
+                                               htlc_update: (htlc_source, hash)
+                                       }
+                               },
+                               1 => {
+                                       let descriptor = Readable::read(reader)?;
+                                       OnchainEvent::MaturingOutput {
+                                               descriptor
+                                       }
+                               },
+                               _ => return Err(DecodeError::InvalidValue),
+                       };
+                       onchain_events_awaiting_threshold_conf.push(OnchainEventEntry { txid, height, event });
                }
 
                let outputs_to_watch_len: u64 = Readable::read(reader)?;
@@ -2538,52 +2974,60 @@ impl<'a, ChanSigner: ChannelKeys, K: KeysInterface<ChanKeySigner = ChanSigner>>
                let lockdown_from_offchain = Readable::read(reader)?;
                let holder_tx_signed = Readable::read(reader)?;
 
-               Ok((last_block_hash.clone(), ChannelMonitor {
-                       latest_update_id,
-                       commitment_transaction_number_obscure_factor,
+               read_tlv_fields!(reader, {}, {});
 
-                       destination_script,
-                       broadcasted_holder_revokable_script,
-                       counterparty_payment_script,
-                       shutdown_script,
+               let mut secp_ctx = Secp256k1::new();
+               secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
 
-                       key_derivation_params,
-                       holder_revocation_basepoint,
-                       funding_info,
-                       current_counterparty_commitment_txid,
-                       prev_counterparty_commitment_txid,
+               Ok((best_block.block_hash(), ChannelMonitor {
+                       inner: Mutex::new(ChannelMonitorImpl {
+                               latest_update_id,
+                               commitment_transaction_number_obscure_factor,
 
-                       counterparty_tx_cache,
-                       funding_redeemscript,
-                       channel_value_satoshis,
-                       their_cur_revocation_points,
+                               destination_script,
+                               broadcasted_holder_revokable_script,
+                               counterparty_payment_script,
+                               shutdown_script,
 
-                       on_holder_tx_csv,
+                               channel_keys_id,
+                               holder_revocation_basepoint,
+                               funding_info,
+                               current_counterparty_commitment_txid,
+                               prev_counterparty_commitment_txid,
 
-                       commitment_secrets,
-                       counterparty_claimable_outpoints,
-                       counterparty_commitment_txn_on_chain,
-                       counterparty_hash_commitment_number,
+                               counterparty_tx_cache,
+                               funding_redeemscript,
+                               channel_value_satoshis,
+                               their_cur_revocation_points,
 
-                       prev_holder_signed_commitment_tx,
-                       current_holder_commitment_tx,
-                       current_counterparty_commitment_number,
-                       current_holder_commitment_number,
+                               on_holder_tx_csv,
 
-                       payment_preimages,
-                       pending_monitor_events,
-                       pending_events,
+                               commitment_secrets,
+                               counterparty_claimable_outpoints,
+                               counterparty_commitment_txn_on_chain,
+                               counterparty_hash_commitment_number,
 
-                       onchain_events_waiting_threshold_conf,
-                       outputs_to_watch,
+                               prev_holder_signed_commitment_tx,
+                               current_holder_commitment_tx,
+                               current_counterparty_commitment_number,
+                               current_holder_commitment_number,
 
-                       onchain_tx_handler,
+                               payment_preimages,
+                               pending_monitor_events,
+                               pending_events,
 
-                       lockdown_from_offchain,
-                       holder_tx_signed,
+                               onchain_events_awaiting_threshold_conf,
+                               outputs_to_watch,
 
-                       last_block_hash,
-                       secp_ctx: Secp256k1::new(),
+                               onchain_tx_handler,
+
+                               lockdown_from_offchain,
+                               holder_tx_signed,
+
+                               best_block,
+
+                               secp_ctx,
+                       }),
                }))
        }
 }
@@ -2599,10 +3043,12 @@ mod tests {
        use bitcoin::hashes::sha256::Hash as Sha256;
        use bitcoin::hashes::hex::FromHex;
        use bitcoin::hash_types::Txid;
+       use bitcoin::network::constants::Network;
        use hex;
        use chain::channelmonitor::ChannelMonitor;
        use chain::transaction::OutPoint;
-       use ln::channelmanager::{PaymentPreimage, PaymentHash};
+       use ln::{PaymentPreimage, PaymentHash};
+       use ln::channelmanager::BestBlock;
        use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
        use ln::chan_utils;
        use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
@@ -2610,7 +3056,7 @@ mod tests {
        use bitcoin::secp256k1::key::{SecretKey,PublicKey};
        use bitcoin::secp256k1::Secp256k1;
        use std::sync::{Arc, Mutex};
-       use chain::keysinterface::InMemoryChannelKeys;
+       use chain::keysinterface::InMemorySigner;
 
        #[test]
        fn test_prune_preimages() {
@@ -2661,12 +3107,12 @@ mod tests {
                macro_rules! test_preimages_exist {
                        ($preimages_slice: expr, $monitor: expr) => {
                                for preimage in $preimages_slice {
-                                       assert!($monitor.payment_preimages.contains_key(&preimage.1));
+                                       assert!($monitor.inner.lock().unwrap().payment_preimages.contains_key(&preimage.1));
                                }
                        }
                }
 
-               let keys = InMemoryChannelKeys::new(
+               let keys = InMemorySigner::new(
                        &secp_ctx,
                        SecretKey::from_slice(&[41; 32]).unwrap(),
                        SecretKey::from_slice(&[41; 32]).unwrap(),
@@ -2675,7 +3121,7 @@ mod tests {
                        SecretKey::from_slice(&[41; 32]).unwrap(),
                        [41; 32],
                        0,
-                       (0, 0)
+                       [0; 32]
                );
 
                let counterparty_pubkeys = ChannelPublicKeys {
@@ -2698,12 +3144,13 @@ mod tests {
                };
                // Prune with one old state and a holder commitment tx holding a few overlaps with the
                // old state.
-               let mut monitor = ChannelMonitor::new(keys,
-                                                     &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
-                                                     (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
-                                                     &channel_parameters,
-                                                     Script::new(), 46, 0,
-                                                     HolderCommitmentTransaction::dummy());
+               let best_block = BestBlock::from_genesis(Network::Testnet);
+               let monitor = ChannelMonitor::new(Secp256k1::new(), keys,
+                                                 &PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()), 0, &Script::new(),
+                                                 (OutPoint { txid: Txid::from_slice(&[43; 32]).unwrap(), index: 0 }, Script::new()),
+                                                 &channel_parameters,
+                                                 Script::new(), 46, 0,
+                                                 HolderCommitmentTransaction::dummy(), best_block);
 
                monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..10])).unwrap();
                let dummy_txid = dummy_tx.txid();
@@ -2719,14 +3166,14 @@ mod tests {
                let mut secret = [0; 32];
                secret[0..32].clone_from_slice(&hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
                monitor.provide_secret(281474976710655, secret.clone()).unwrap();
-               assert_eq!(monitor.payment_preimages.len(), 15);
+               assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 15);
                test_preimages_exist!(&preimages[0..10], monitor);
                test_preimages_exist!(&preimages[15..20], monitor);
 
                // Now provide a further secret, pruning preimages 15-17
                secret[0..32].clone_from_slice(&hex::decode("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
                monitor.provide_secret(281474976710654, secret.clone()).unwrap();
-               assert_eq!(monitor.payment_preimages.len(), 13);
+               assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 13);
                test_preimages_exist!(&preimages[0..10], monitor);
                test_preimages_exist!(&preimages[17..20], monitor);
 
@@ -2735,7 +3182,7 @@ mod tests {
                monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..5])).unwrap();
                secret[0..32].clone_from_slice(&hex::decode("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
                monitor.provide_secret(281474976710653, secret.clone()).unwrap();
-               assert_eq!(monitor.payment_preimages.len(), 12);
+               assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
                test_preimages_exist!(&preimages[0..10], monitor);
                test_preimages_exist!(&preimages[18..20], monitor);
 
@@ -2743,7 +3190,7 @@ mod tests {
                monitor.provide_latest_holder_commitment_tx(HolderCommitmentTransaction::dummy(), preimages_to_holder_htlcs!(preimages[0..3])).unwrap();
                secret[0..32].clone_from_slice(&hex::decode("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
                monitor.provide_secret(281474976710652, secret.clone()).unwrap();
-               assert_eq!(monitor.payment_preimages.len(), 5);
+               assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);
                test_preimages_exist!(&preimages[0..5], monitor);
        }
 
@@ -2816,7 +3263,7 @@ mod tests {
                                sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
                        }
                }
-               assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
+               assert_eq!(base_weight + OnchainTxHandler::<InMemorySigner>::get_witnesses_weight(&inputs_des[..]),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
 
                // Claim tx with 1 offered HTLCs, 3 received HTLCs
                claim_tx.input.clear();
@@ -2840,7 +3287,7 @@ mod tests {
                                sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
                        }
                }
-               assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
+               assert_eq!(base_weight + OnchainTxHandler::<InMemorySigner>::get_witnesses_weight(&inputs_des[..]),  claim_tx.get_weight() + /* max_length_sig */ (73 * inputs_des.len() - sum_actual_sigs));
 
                // Justice tx with 1 revoked HTLC-Success tx output
                claim_tx.input.clear();
@@ -2862,7 +3309,7 @@ mod tests {
                                sign_input!(sighash_parts, idx, 0, inp, sum_actual_sigs);
                        }
                }
-               assert_eq!(base_weight + OnchainTxHandler::<InMemoryChannelKeys>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() - sum_actual_sigs));
+               assert_eq!(base_weight + OnchainTxHandler::<InMemorySigner>::get_witnesses_weight(&inputs_des[..]), claim_tx.get_weight() + /* max_length_isg */ (73 * inputs_des.len() - sum_actual_sigs));
        }
 
        // Further testing is done in the ChannelManager integration tests.