channelmanager.rs

// This file is Copyright its original authors, visible in version control
// history.
//
// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// You may not use this file except in accordance with one or both of these
// licenses.

//! The top-level channel management and payment tracking stuff lives here.
//!
//! The ChannelManager is the main chunk of logic implementing the lightning protocol and is
//! responsible for tracking which channels are open, HTLCs are in flight and reestablishing those
//! upon reconnect to the relevant peer(s).
//!
//! It does not manage routing logic (see routing::router::get_route for that) nor does it manage constructing
//! on-chain transactions (it only monitors the chain to watch for any force-closes that might
//! imply it needs to fail HTLCs/payments/channels it manages).
//!

use bitcoin::blockdata::block::{Block, BlockHeader};
use bitcoin::blockdata::transaction::Transaction;
use bitcoin::blockdata::constants::genesis_block;
use bitcoin::network::constants::Network;

use bitcoin::hashes::{Hash, HashEngine};
use bitcoin::hashes::hmac::{Hmac, HmacEngine};
use bitcoin::hashes::sha256::Hash as Sha256;
use bitcoin::hashes::sha256d::Hash as Sha256dHash;
use bitcoin::hashes::cmp::fixed_time_eq;
use bitcoin::hash_types::{BlockHash, Txid};

use bitcoin::secp256k1::key::{SecretKey,PublicKey};
use bitcoin::secp256k1::Secp256k1;
use bitcoin::secp256k1::ecdh::SharedSecret;
use bitcoin::secp256k1;

use chain;
use chain::{Confirm, Watch, BestBlock};
use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, ChannelMonitorUpdateErr, HTLC_FAIL_BACK_BUFFER, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY, MonitorEvent, CLOSED_CHANNEL_UPDATE_ID};
use chain::transaction::{OutPoint, TransactionData};
// Since this struct is returned in `list_channels` methods, expose it here in case users want to
// construct one themselves.
use ln::{PaymentHash, PaymentPreimage, PaymentSecret};
pub use ln::channel::CounterpartyForwardingInfo;
use ln::channel::{Channel, ChannelError, ChannelUpdateStatus};
use ln::features::{InitFeatures, NodeFeatures};
use routing::router::{Route, RouteHop};
use ln::msgs;
use ln::msgs::NetAddress;
use ln::onion_utils;
use ln::msgs::{ChannelMessageHandler, DecodeError, LightningError, OptionalField};
use chain::keysinterface::{Sign, KeysInterface, KeysManager, InMemorySigner};
use util::config::UserConfig;
use util::events::{EventHandler, EventsProvider, MessageSendEvent, MessageSendEventsProvider};
use util::{byte_utils, events};
use util::ser::{Readable, ReadableArgs, MaybeReadable, Writeable, Writer};
use util::chacha20::{ChaCha20, ChaChaReader};
use util::logger::Logger;
use util::errors::APIError;

use prelude::*;
use core::{cmp, mem};
use core::cell::RefCell;
use std::io::{Cursor, Read};
use std::sync::{Arc, Condvar, Mutex, MutexGuard, RwLock, RwLockReadGuard};
use core::sync::atomic::{AtomicUsize, Ordering};
use core::time::Duration;
#[cfg(any(test, feature = "allow_wallclock_use"))]
use std::time::Instant;
use core::ops::Deref;
use bitcoin::hashes::hex::ToHex;

// We hold various information about HTLC relay in the HTLC objects in Channel itself:
//
// Upon receipt of an HTLC from a peer, we'll give it a PendingHTLCStatus indicating if it should
// forward the HTLC with information it will give back to us when it does so, or if it should Fail
// the HTLC with the relevant message for the Channel to handle giving to the remote peer.
//
// Once said HTLC is committed in the Channel, if the PendingHTLCStatus indicated Forward, the
// Channel will return the PendingHTLCInfo back to us, and we will create an HTLCForwardInfo
// with it to track where it came from (in case of onwards-forward error), waiting a random delay
// before we forward it.
//
// We will then use HTLCForwardInfo's PendingHTLCInfo to construct an outbound HTLC, with a
// relevant HTLCSource::PreviousHopData filled in to indicate where it came from (which we can use
// to either fail-backwards or fulfill the HTLC backwards along the relevant path).
// Alternatively, we can fill an outbound HTLC with a HTLCSource::OutboundRoute indicating this is
// our payment, which we can use to decode errors or inform the user that the payment was sent.

#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
enum PendingHTLCRouting {
	Forward {
		onion_packet: msgs::OnionPacket,
		short_channel_id: u64, // This should be NonZero<u64> eventually when we bump MSRV
	},
	Receive {
		payment_data: msgs::FinalOnionHopData,
		incoming_cltv_expiry: u32, // Used to track when we should expire pending HTLCs that go unclaimed
	},
}

#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
pub(super) struct PendingHTLCInfo {
	routing: PendingHTLCRouting,
	incoming_shared_secret: [u8; 32],
	payment_hash: PaymentHash,
	pub(super) amt_to_forward: u64,
	pub(super) outgoing_cltv_value: u32,
}

#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
pub(super) enum HTLCFailureMsg {
	Relay(msgs::UpdateFailHTLC),
	Malformed(msgs::UpdateFailMalformedHTLC),
}

/// Stores whether we can't forward an HTLC or relevant forwarding info
#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
pub(super) enum PendingHTLCStatus {
	Forward(PendingHTLCInfo),
	Fail(HTLCFailureMsg),
}

pub(super) enum HTLCForwardInfo {
	AddHTLC {
		forward_info: PendingHTLCInfo,

		// These fields are produced in `forward_htlcs()` and consumed in
		// `process_pending_htlc_forwards()` for constructing the
		// `HTLCSource::PreviousHopData` for failed and forwarded
		// HTLCs.
		prev_short_channel_id: u64,
		prev_htlc_id: u64,
		prev_funding_outpoint: OutPoint,
	},
	FailHTLC {
		htlc_id: u64,
		err_packet: msgs::OnionErrorPacket,
	},
}

/// Tracks the inbound corresponding to an outbound HTLC
#[derive(Clone, PartialEq)]
pub(crate) struct HTLCPreviousHopData {
	short_channel_id: u64,
	htlc_id: u64,
	incoming_packet_shared_secret: [u8; 32],

	// This field is consumed by `claim_funds_from_hop()` when updating a force-closed backwards
	// channel with a preimage provided by the forward channel.
	outpoint: OutPoint,
}

struct ClaimableHTLC {
	prev_hop: HTLCPreviousHopData,
	value: u64,
	/// Contains a total_msat (which may differ from value if this is a Multi-Path Payment) and a
	/// payment_secret which prevents path-probing attacks and can associate different HTLCs which
	/// are part of the same payment.
	payment_data: msgs::FinalOnionHopData,
	cltv_expiry: u32,
}

/// Tracks the inbound corresponding to an outbound HTLC
#[derive(Clone, PartialEq)]
pub(crate) enum HTLCSource {
	PreviousHopData(HTLCPreviousHopData),
	OutboundRoute {
		path: Vec<RouteHop>,
		session_priv: SecretKey,
		/// Technically we can recalculate this from the route, but we cache it here to avoid
		/// doing a double-pass on route when we get a failure back
		first_hop_htlc_msat: u64,
	},
}
#[cfg(test)]
impl HTLCSource {
	pub fn dummy() -> Self {
		HTLCSource::OutboundRoute {
			path: Vec::new(),
			session_priv: SecretKey::from_slice(&[1; 32]).unwrap(),
			first_hop_htlc_msat: 0,
		}
	}
}

#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
pub(super) enum HTLCFailReason {
	LightningError {
		err: msgs::OnionErrorPacket,
	},
	Reason {
		failure_code: u16,
		data: Vec<u8>,
	}
}

type ShutdownResult = (Option<(OutPoint, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash)>);

/// Error type returned across the channel_state mutex boundary. When an Err is generated for a
/// Channel, we generally end up with a ChannelError::Close for which we have to close the channel
/// immediately (ie with no further calls on it made). Thus, this step happens inside a
/// channel_state lock. We then return the set of things that need to be done outside the lock in
/// this struct and call handle_error!() on it.

struct MsgHandleErrInternal {
	err: msgs::LightningError,
	shutdown_finish: Option<(ShutdownResult, Option<msgs::ChannelUpdate>)>,
}
impl MsgHandleErrInternal {
	#[inline]
	fn send_err_msg_no_close(err: String, channel_id: [u8; 32]) -> Self {
		Self {
			err: LightningError {
				err: err.clone(),
				action: msgs::ErrorAction::SendErrorMessage {
					msg: msgs::ErrorMessage {
						channel_id,
						data: err
					},
				},
			},
			shutdown_finish: None,
		}
	}
	#[inline]
	fn ignore_no_close(err: String) -> Self {
		Self {
			err: LightningError {
				err,
				action: msgs::ErrorAction::IgnoreError,
			},
			shutdown_finish: None,
		}
	}
	#[inline]
	fn from_no_close(err: msgs::LightningError) -> Self {
		Self { err, shutdown_finish: None }
	}
	#[inline]
	fn from_finish_shutdown(err: String, channel_id: [u8; 32], shutdown_res: ShutdownResult, channel_update: Option<msgs::ChannelUpdate>) -> Self {
		Self {
			err: LightningError {
				err: err.clone(),
				action: msgs::ErrorAction::SendErrorMessage {
					msg: msgs::ErrorMessage {
						channel_id,
						data: err
					},
				},
			},
			shutdown_finish: Some((shutdown_res, channel_update)),
		}
	}
	#[inline]
	fn from_chan_no_close(err: ChannelError, channel_id: [u8; 32]) -> Self {
		Self {
			err: match err {
				ChannelError::Ignore(msg) => LightningError {
					err: msg,
					action: msgs::ErrorAction::IgnoreError,
				},
				ChannelError::Close(msg) => LightningError {
					err: msg.clone(),
					action: msgs::ErrorAction::SendErrorMessage {
						msg: msgs::ErrorMessage {
							channel_id,
							data: msg
						},
					},
				},
				ChannelError::CloseDelayBroadcast(msg) => LightningError {
					err: msg.clone(),
					action: msgs::ErrorAction::SendErrorMessage {
						msg: msgs::ErrorMessage {
							channel_id,
							data: msg
						},
					},
				},
			},
			shutdown_finish: None,
		}
	}
}

/// We hold back HTLCs we intend to relay for a random interval greater than this (see
/// Event::PendingHTLCsForwardable for the API guidelines indicating how long should be waited).
/// This provides some limited amount of privacy. Ideally this would range from somewhere like one
/// second to 30 seconds, but people expect lightning to be, you know, kinda fast, sadly.
const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u64 = 100;

/// For events which result in both a RevokeAndACK and a CommitmentUpdate, by default they should
/// be sent in the order they appear in the return value, however sometimes the order needs to be
/// variable at runtime (eg Channel::channel_reestablish needs to re-send messages in the order
/// they were originally sent). In those cases, this enum is also returned.
#[derive(Clone, PartialEq)]
pub(super) enum RAACommitmentOrder {
	/// Send the CommitmentUpdate messages first
	CommitmentFirst,
	/// Send the RevokeAndACK message first
	RevokeAndACKFirst,
}

// Note this is only exposed in cfg(test):
pub(super) struct ChannelHolder<Signer: Sign> {
	pub(super) by_id: HashMap<[u8; 32], Channel<Signer>>,
	pub(super) short_to_id: HashMap<u64, [u8; 32]>,
	/// short channel id -> forward infos. Key of 0 means payments received
	/// Note that while this is held in the same mutex as the channels themselves, no consistency
	/// guarantees are made about the existence of a channel with the short id here, nor the short
	/// ids in the PendingHTLCInfo!
	pub(super) forward_htlcs: HashMap<u64, Vec<HTLCForwardInfo>>,
	/// Map from payment hash to any HTLCs which are to us and can be failed/claimed by the user.
	/// Note that while this is held in the same mutex as the channels themselves, no consistency
	/// guarantees are made about the channels given here actually existing anymore by the time you
	/// go to read them!
	claimable_htlcs: HashMap<PaymentHash, Vec<ClaimableHTLC>>,
	/// Messages to send to peers - pushed to in the same lock that they are generated in (except
	/// for broadcast messages, where ordering isn't as strict).
	pub(super) pending_msg_events: Vec<MessageSendEvent>,
}

/// Events which we process internally but cannot be procsesed immediately at the generation site
/// for some reason. They are handled in timer_tick_occurred, so may be processed with
/// quite some time lag.
enum BackgroundEvent {
	/// Handle a ChannelMonitorUpdate that closes a channel, broadcasting its current latest holder
	/// commitment transaction.
	ClosingMonitorUpdate((OutPoint, ChannelMonitorUpdate)),
}

/// State we hold per-peer. In the future we should put channels in here, but for now we only hold
/// the latest Init features we heard from the peer.
struct PeerState {
	latest_features: InitFeatures,
}

/// Stores a PaymentSecret and any other data we may need to validate an inbound payment is
/// actually ours and not some duplicate HTLC sent to us by a node along the route.
///
/// For users who don't want to bother doing their own payment preimage storage, we also store that
/// here.
struct PendingInboundPayment {
	/// The payment secret that the sender must use for us to accept this payment
	payment_secret: PaymentSecret,
	/// Time at which this HTLC expires - blocks with a header time above this value will result in
	/// this payment being removed.
	expiry_time: u64,
	/// Arbitrary identifier the user specifies (or not)
	user_payment_id: u64,
	// Other required attributes of the payment, optionally enforced:
	payment_preimage: Option<PaymentPreimage>,
	min_value_msat: Option<u64>,
}

/// SimpleArcChannelManager is useful when you need a ChannelManager with a static lifetime, e.g.
/// when you're using lightning-net-tokio (since tokio::spawn requires parameters with static
/// lifetimes). Other times you can afford a reference, which is more efficient, in which case
/// SimpleRefChannelManager is the more appropriate type. Defining these type aliases prevents
/// issues such as overly long function definitions. Note that the ChannelManager can take any
/// type that implements KeysInterface for its keys manager, but this type alias chooses the
/// concrete type of the KeysManager.
pub type SimpleArcChannelManager<M, T, F, L> = ChannelManager<InMemorySigner, Arc<M>, Arc<T>, Arc<KeysManager>, Arc<F>, Arc<L>>;

/// SimpleRefChannelManager is a type alias for a ChannelManager reference, and is the reference
/// counterpart to the SimpleArcChannelManager type alias. Use this type by default when you don't
/// need a ChannelManager with a static lifetime. You'll need a static lifetime in cases such as
/// usage of lightning-net-tokio (since tokio::spawn requires parameters with static lifetimes).
/// But if this is not necessary, using a reference is more efficient. Defining these type aliases
/// helps with issues such as long function definitions. Note that the ChannelManager can take any
/// type that implements KeysInterface for its keys manager, but this type alias chooses the
/// concrete type of the KeysManager.
pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, M, T, F, L> = ChannelManager<InMemorySigner, &'a M, &'b T, &'c KeysManager, &'d F, &'e L>;

/// Manager which keeps track of a number of channels and sends messages to the appropriate
/// channel, also tracking HTLC preimages and forwarding onion packets appropriately.
///
/// Implements ChannelMessageHandler, handling the multi-channel parts and passing things through
/// to individual Channels.
///
/// Implements Writeable to write out all channel state to disk. Implies peer_disconnected() for
/// all peers during write/read (though does not modify this instance, only the instance being
/// serialized). This will result in any channels which have not yet exchanged funding_created (ie
/// called funding_transaction_generated for outbound channels).
///
/// Note that you can be a bit lazier about writing out ChannelManager than you can be with
/// ChannelMonitors. With ChannelMonitors you MUST write each monitor update out to disk before
/// returning from chain::Watch::watch_/update_channel, with ChannelManagers, writing updates
/// happens out-of-band (and will prevent any other ChannelManager operations from occurring during
/// the serialization process). If the deserialized version is out-of-date compared to the
/// ChannelMonitors passed by reference to read(), those channels will be force-closed based on the
/// ChannelMonitor state and no funds will be lost (mod on-chain transaction fees).
///
/// Note that the deserializer is only implemented for (BlockHash, ChannelManager), which
/// tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along
/// the "reorg path" (ie call block_disconnected() until you get to a common block and then call
/// block_connected() to step towards your best block) upon deserialization before using the
/// object!
///
/// Note that ChannelManager is responsible for tracking liveness of its channels and generating
/// ChannelUpdate messages informing peers that the channel is temporarily disabled. To avoid
/// spam due to quick disconnection/reconnection, updates are not sent until the channel has been
/// offline for a full minute. In order to track this, you must call
/// timer_tick_occurred roughly once per minute, though it doesn't have to be perfect.
///
/// Rather than using a plain ChannelManager, it is preferable to use either a SimpleArcChannelManager
/// a SimpleRefChannelManager, for conciseness. See their documentation for more details, but
/// essentially you should default to using a SimpleRefChannelManager, and use a
/// SimpleArcChannelManager when you require a ChannelManager with a static lifetime, such as when
/// you're using lightning-net-tokio.
pub struct ChannelManager<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
	where M::Target: chain::Watch<Signer>,
        T::Target: BroadcasterInterface,
        K::Target: KeysInterface<Signer = Signer>,
        F::Target: FeeEstimator,
				L::Target: Logger,
{
	default_configuration: UserConfig,
	genesis_hash: BlockHash,
	fee_estimator: F,
	chain_monitor: M,
	tx_broadcaster: T,

	#[cfg(test)]
	pub(super) best_block: RwLock<BestBlock>,
	#[cfg(not(test))]
	best_block: RwLock<BestBlock>,
	secp_ctx: Secp256k1<secp256k1::All>,

	#[cfg(any(test, feature = "_test_utils"))]
	pub(super) channel_state: Mutex<ChannelHolder<Signer>>,
	#[cfg(not(any(test, feature = "_test_utils")))]
	channel_state: Mutex<ChannelHolder<Signer>>,

	/// Storage for PaymentSecrets and any requirements on future inbound payments before we will
	/// expose them to users via a PaymentReceived event. HTLCs which do not meet the requirements
	/// here are failed when we process them as pending-forwardable-HTLCs, and entries are removed
	/// after we generate a PaymentReceived upon receipt of all MPP parts or when they time out.
	/// Locked *after* channel_state.
	pending_inbound_payments: Mutex<HashMap<PaymentHash, PendingInboundPayment>>,

	/// The session_priv bytes of outbound payments which are pending resolution.
	/// The authoritative state of these HTLCs resides either within Channels or ChannelMonitors
	/// (if the channel has been force-closed), however we track them here to prevent duplicative
	/// PaymentSent/PaymentFailed events. Specifically, in the case of a duplicative
	/// update_fulfill_htlc message after a reconnect, we may "claim" a payment twice.
	/// Additionally, because ChannelMonitors are often not re-serialized after connecting block(s)
	/// which may generate a claim event, we may receive similar duplicate claim/fail MonitorEvents
	/// after reloading from disk while replaying blocks against ChannelMonitors.
	///
	/// Locked *after* channel_state.
	pending_outbound_payments: Mutex<HashSet<[u8; 32]>>,

	our_network_key: SecretKey,
	our_network_pubkey: PublicKey,

	/// Used to track the last value sent in a node_announcement "timestamp" field. We ensure this
	/// value increases strictly since we don't assume access to a time source.
	last_node_announcement_serial: AtomicUsize,

	/// The highest block timestamp we've seen, which is usually a good guess at the current time.
	/// Assuming most miners are generating blocks with reasonable timestamps, this shouldn't be
	/// very far in the past, and can only ever be up to two hours in the future.
	highest_seen_timestamp: AtomicUsize,

	/// The bulk of our storage will eventually be here (channels and message queues and the like).
	/// If we are connected to a peer we always at least have an entry here, even if no channels
	/// are currently open with that peer.
	/// Because adding or removing an entry is rare, we usually take an outer read lock and then
	/// operate on the inner value freely. Sadly, this prevents parallel operation when opening a
	/// new channel.
	per_peer_state: RwLock<HashMap<PublicKey, Mutex<PeerState>>>,

	pending_events: Mutex<Vec<events::Event>>,
	pending_background_events: Mutex<Vec<BackgroundEvent>>,
	/// Used when we have to take a BIG lock to make sure everything is self-consistent.
	/// Essentially just when we're serializing ourselves out.
	/// Taken first everywhere where we are making changes before any other locks.
	/// When acquiring this lock in read mode, rather than acquiring it directly, call
	/// `PersistenceNotifierGuard::notify_on_drop(..)` and pass the lock to it, to ensure the
	/// PersistenceNotifier the lock contains sends out a notification when the lock is released.
	total_consistency_lock: RwLock<()>,

	persistence_notifier: PersistenceNotifier,

	keys_manager: K,

	logger: L,
}

/// Chain-related parameters used to construct a new `ChannelManager`.
///
/// Typically, the block-specific parameters are derived from the best block hash for the network,
/// as a newly constructed `ChannelManager` will not have created any channels yet. These parameters
/// are not needed when deserializing a previously constructed `ChannelManager`.
#[derive(Clone, Copy, PartialEq)]
pub struct ChainParameters {
	/// The network for determining the `chain_hash` in Lightning messages.
	pub network: Network,

	/// The hash and height of the latest block successfully connected.
	///
	/// Used to track on-chain channel funding outputs and send payments with reliable timelocks.
	pub best_block: BestBlock,
}

#[derive(Copy, Clone, PartialEq)]
enum NotifyOption {
	DoPersist,
	SkipPersist,
}

/// Whenever we release the `ChannelManager`'s `total_consistency_lock`, from read mode, it is
/// desirable to notify any listeners on `await_persistable_update_timeout`/
/// `await_persistable_update` when new updates are available for persistence. Therefore, this
/// struct is responsible for locking the total consistency lock and, upon going out of scope,
/// sending the aforementioned notification (since the lock being released indicates that the
/// updates are ready for persistence).
///
/// We allow callers to either always notify by constructing with `notify_on_drop` or choose to
/// notify or not based on whether relevant changes have been made, providing a closure to
/// `optionally_notify` which returns a `NotifyOption`.
struct PersistenceNotifierGuard<'a, F: Fn() -> NotifyOption> {
	persistence_notifier: &'a PersistenceNotifier,
	should_persist: F,
	// We hold onto this result so the lock doesn't get released immediately.
	_read_guard: RwLockReadGuard<'a, ()>,
}

impl<'a> PersistenceNotifierGuard<'a, fn() -> NotifyOption> { // We don't care what the concrete F is here, it's unused
	fn notify_on_drop(lock: &'a RwLock<()>, notifier: &'a PersistenceNotifier) -> PersistenceNotifierGuard<'a, impl Fn() -> NotifyOption> {
		PersistenceNotifierGuard::optionally_notify(lock, notifier, || -> NotifyOption { NotifyOption::DoPersist })
	}

	fn optionally_notify<F: Fn() -> NotifyOption>(lock: &'a RwLock<()>, notifier: &'a PersistenceNotifier, persist_check: F) -> PersistenceNotifierGuard<'a, F> {
		let read_guard = lock.read().unwrap();

		PersistenceNotifierGuard {
			persistence_notifier: notifier,
			should_persist: persist_check,
			_read_guard: read_guard,
		}
	}
}

impl<'a, F: Fn() -> NotifyOption> Drop for PersistenceNotifierGuard<'a, F> {
	fn drop(&mut self) {
		if (self.should_persist)() == NotifyOption::DoPersist {
			self.persistence_notifier.notify();
		}
	}
}

/// The amount of time in blocks we require our counterparty wait to claim their money (ie time
/// between when we, or our watchtower, must check for them having broadcast a theft transaction).
///
/// This can be increased (but not decreased) through [`ChannelHandshakeConfig::our_to_self_delay`]
///
/// [`ChannelHandshakeConfig::our_to_self_delay`]: crate::util::config::ChannelHandshakeConfig::our_to_self_delay
pub const BREAKDOWN_TIMEOUT: u16 = 6 * 24;
/// The amount of time in blocks we're willing to wait to claim money back to us. This matches
/// the maximum required amount in lnd as of March 2021.
pub(crate) const MAX_LOCAL_BREAKDOWN_TIMEOUT: u16 = 2 * 6 * 24 * 7;

/// The minimum number of blocks between an inbound HTLC's CLTV and the corresponding outbound
/// HTLC's CLTV. The current default represents roughly seven hours of blocks at six blocks/hour.
///
/// This can be increased (but not decreased) through [`ChannelConfig::cltv_expiry_delta`]
///
/// [`ChannelConfig::cltv_expiry_delta`]: crate::util::config::ChannelConfig::cltv_expiry_delta
// This should always be a few blocks greater than channelmonitor::CLTV_CLAIM_BUFFER,
// i.e. the node we forwarded the payment on to should always have enough room to reliably time out
// the HTLC via a full update_fail_htlc/commitment_signed dance before we hit the
// CLTV_CLAIM_BUFFER point (we static assert that it's at least 3 blocks more).
pub const MIN_CLTV_EXPIRY_DELTA: u16 = 6*7;
pub(super) const CLTV_FAR_FAR_AWAY: u32 = 6 * 24 * 7; //TODO?

/// Minimum CLTV difference between the current block height and received inbound payments.
/// Invoices generated for payment to us must set their `min_final_cltv_expiry` field to at least
/// this value.
// Note that we fail if exactly HTLC_FAIL_BACK_BUFFER + 1 was used, so we need to add one for
// any payments to succeed. Further, we don't want payments to fail if a block was found while
// a payment was being routed, so we add an extra block to be safe.
pub const MIN_FINAL_CLTV_EXPIRY: u32 = HTLC_FAIL_BACK_BUFFER + 3;

// Check that our CLTV_EXPIRY is at least CLTV_CLAIM_BUFFER + ANTI_REORG_DELAY + LATENCY_GRACE_PERIOD_BLOCKS,
// ie that if the next-hop peer fails the HTLC within
// LATENCY_GRACE_PERIOD_BLOCKS then we'll still have CLTV_CLAIM_BUFFER left to timeout it onchain,
// then waiting ANTI_REORG_DELAY to be reorg-safe on the outbound HLTC and
// failing the corresponding htlc backward, and us now seeing the last block of ANTI_REORG_DELAY before
// LATENCY_GRACE_PERIOD_BLOCKS.
#[deny(const_err)]
#[allow(dead_code)]
const CHECK_CLTV_EXPIRY_SANITY: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - CLTV_CLAIM_BUFFER - ANTI_REORG_DELAY - LATENCY_GRACE_PERIOD_BLOCKS;

// Check for ability of an attacker to make us fail on-chain by delaying an HTLC claim. See
// ChannelMonitor::should_broadcast_holder_commitment_txn for a description of why this is needed.
#[deny(const_err)]
#[allow(dead_code)]
const CHECK_CLTV_EXPIRY_SANITY_2: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - 2*CLTV_CLAIM_BUFFER;

/// Channel parameters which apply to our counterparty. These are split out from [`ChannelDetails`]
/// to better separate parameters.
#[derive(Clone, Debug, PartialEq)]
pub struct ChannelCounterparty {
	/// The node_id of our counterparty
	pub node_id: PublicKey,
	/// The Features the channel counterparty provided upon last connection.
	/// Useful for routing as it is the most up-to-date copy of the counterparty's features and
	/// many routing-relevant features are present in the init context.
	pub features: InitFeatures,
	/// The value, in satoshis, that must always be held in the channel for our counterparty. This
	/// value ensures that if our counterparty broadcasts a revoked state, we can punish them by
	/// claiming at least this value on chain.
	///
	/// This value is not included in [`inbound_capacity_msat`] as it can never be spent.
	///
	/// [`inbound_capacity_msat`]: ChannelDetails::inbound_capacity_msat
	pub unspendable_punishment_reserve: u64,
	/// Information on the fees and requirements that the counterparty requires when forwarding
	/// payments to us through this channel.
	pub forwarding_info: Option<CounterpartyForwardingInfo>,
}

/// Details of a channel, as returned by ChannelManager::list_channels and ChannelManager::list_usable_channels
#[derive(Clone, Debug, PartialEq)]
pub struct ChannelDetails {
	/// The channel's ID (prior to funding transaction generation, this is a random 32 bytes,
	/// thereafter this is the txid of the funding transaction xor the funding transaction output).
	/// Note that this means this value is *not* persistent - it can change once during the
	/// lifetime of the channel.
	pub channel_id: [u8; 32],
	/// Parameters which apply to our counterparty. See individual fields for more information.
	pub counterparty: ChannelCounterparty,
	/// The Channel's funding transaction output, if we've negotiated the funding transaction with
	/// our counterparty already.
	///
	/// Note that, if this has been set, `channel_id` will be equivalent to
	/// `funding_txo.unwrap().to_channel_id()`.
	pub funding_txo: Option<OutPoint>,
	/// The position of the funding transaction in the chain. None if the funding transaction has
	/// not yet been confirmed and the channel fully opened.
	pub short_channel_id: Option<u64>,
	/// The value, in satoshis, of this channel as appears in the funding output
	pub channel_value_satoshis: u64,
	/// The value, in satoshis, that must always be held in the channel for us. This value ensures
	/// that if we broadcast a revoked state, our counterparty can punish us by claiming at least
	/// this value on chain.
	///
	/// This value is not included in [`outbound_capacity_msat`] as it can never be spent.
	///
	/// This value will be `None` for outbound channels until the counterparty accepts the channel.
	///
	/// [`outbound_capacity_msat`]: ChannelDetails::outbound_capacity_msat
	pub unspendable_punishment_reserve: Option<u64>,
	/// The user_id passed in to create_channel, or 0 if the channel was inbound.
	pub user_id: u64,
	/// The available outbound capacity for sending HTLCs to the remote peer. This does not include
	/// any pending HTLCs which are not yet fully resolved (and, thus, who's balance is not
	/// available for inclusion in new outbound HTLCs). This further does not include any pending
	/// outgoing HTLCs which are awaiting some other resolution to be sent.
	///
	/// This value is not exact. Due to various in-flight changes, feerate changes, and our
	/// conflict-avoidance policy, exactly this amount is not likely to be spendable. However, we
	/// should be able to spend nearly this amount.
	pub outbound_capacity_msat: u64,
	/// The available inbound capacity for the remote peer to send HTLCs to us. This does not
	/// include any pending HTLCs which are not yet fully resolved (and, thus, who's balance is not
	/// available for inclusion in new inbound HTLCs).
	/// Note that there are some corner cases not fully handled here, so the actual available
	/// inbound capacity may be slightly higher than this.
	///
	/// This value is not exact. Due to various in-flight changes, feerate changes, and our
	/// counterparty's conflict-avoidance policy, exactly this amount is not likely to be spendable.
	/// However, our counterparty should be able to spend nearly this amount.
	pub inbound_capacity_msat: u64,
	/// The number of required confirmations on the funding transaction before the funding will be
	/// considered "locked". This number is selected by the channel fundee (i.e. us if
	/// [`is_outbound`] is *not* set), and can be selected for inbound channels with
	/// [`ChannelHandshakeConfig::minimum_depth`] or limited for outbound channels with
	/// [`ChannelHandshakeLimits::max_minimum_depth`].
	///
	/// This value will be `None` for outbound channels until the counterparty accepts the channel.
	///
	/// [`is_outbound`]: ChannelDetails::is_outbound
	/// [`ChannelHandshakeConfig::minimum_depth`]: crate::util::config::ChannelHandshakeConfig::minimum_depth
	/// [`ChannelHandshakeLimits::max_minimum_depth`]: crate::util::config::ChannelHandshakeLimits::max_minimum_depth
	pub confirmations_required: Option<u32>,
	/// The number of blocks (after our commitment transaction confirms) that we will need to wait
	/// until we can claim our funds after we force-close the channel. During this time our
	/// counterparty is allowed to punish us if we broadcasted a stale state. If our counterparty
	/// force-closes the channel and broadcasts a commitment transaction we do not have to wait any
	/// time to claim our non-HTLC-encumbered funds.
	///
	/// This value will be `None` for outbound channels until the counterparty accepts the channel.
	pub force_close_spend_delay: Option<u16>,
	/// True if the channel was initiated (and thus funded) by us.
	pub is_outbound: bool,
	/// True if the channel is confirmed, funding_locked messages have been exchanged, and the
	/// channel is not currently being shut down. `funding_locked` message exchange implies the
	/// required confirmation count has been reached (and we were connected to the peer at some
	/// point after the funding transaction received enough confirmations). The required
	/// confirmation count is provided in [`confirmations_required`].
	///
	/// [`confirmations_required`]: ChannelDetails::confirmations_required
	pub is_funding_locked: bool,
	/// True if the channel is (a) confirmed and funding_locked messages have been exchanged, (b)
	/// the peer is connected, and (c) the channel is not currently negotiating a shutdown.
	///
	/// This is a strict superset of `is_funding_locked`.
	pub is_usable: bool,
	/// True if this channel is (or will be) publicly-announced.
	pub is_public: bool,
}

/// If a payment fails to send, it can be in one of several states. This enum is returned as the
/// Err() type describing which state the payment is in, see the description of individual enum
/// states for more.
#[derive(Clone, Debug)]
pub enum PaymentSendFailure {
	/// A parameter which was passed to send_payment was invalid, preventing us from attempting to
	/// send the payment at all. No channel state has been changed or messages sent to peers, and
	/// once you've changed the parameter at error, you can freely retry the payment in full.
	ParameterError(APIError),
	/// A parameter in a single path which was passed to send_payment was invalid, preventing us
	/// from attempting to send the payment at all. No channel state has been changed or messages
	/// sent to peers, and once you've changed the parameter at error, you can freely retry the
	/// payment in full.
	///
	/// The results here are ordered the same as the paths in the route object which was passed to
	/// send_payment.
	PathParameterError(Vec<Result<(), APIError>>),
	/// All paths which were attempted failed to send, with no channel state change taking place.
	/// You can freely retry the payment in full (though you probably want to do so over different
	/// paths than the ones selected).
	AllFailedRetrySafe(Vec<APIError>),
	/// Some paths which were attempted failed to send, though possibly not all. At least some
	/// paths have irrevocably committed to the HTLC and retrying the payment in full would result
	/// in over-/re-payment.
	///
	/// The results here are ordered the same as the paths in the route object which was passed to
	/// send_payment, and any Errs which are not APIError::MonitorUpdateFailed can be safely
	/// retried (though there is currently no API with which to do so).
	///
	/// Any entries which contain Err(APIError::MonitorUpdateFailed) or Ok(()) MUST NOT be retried
	/// as they will result in over-/re-payment. These HTLCs all either successfully sent (in the
	/// case of Ok(())) or will send once channel_monitor_updated is called on the next-hop channel
	/// with the latest update_id.
	PartialFailure(Vec<Result<(), APIError>>),
}

macro_rules! handle_error {
	($self: ident, $internal: expr, $counterparty_node_id: expr) => {
		match $internal {
			Ok(msg) => Ok(msg),
			Err(MsgHandleErrInternal { err, shutdown_finish }) => {
				#[cfg(debug_assertions)]
				{
					// In testing, ensure there are no deadlocks where the lock is already held upon
					// entering the macro.
					assert!($self.channel_state.try_lock().is_ok());
				}

				let mut msg_events = Vec::with_capacity(2);

				if let Some((shutdown_res, update_option)) = shutdown_finish {
					$self.finish_force_close_channel(shutdown_res);
					if let Some(update) = update_option {
						msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
							msg: update
						});
					}
				}

				log_error!($self.logger, "{}", err.err);
				if let msgs::ErrorAction::IgnoreError = err.action {
				} else {
					msg_events.push(events::MessageSendEvent::HandleError {
						node_id: $counterparty_node_id,
						action: err.action.clone()
					});
				}

				if !msg_events.is_empty() {
					$self.channel_state.lock().unwrap().pending_msg_events.append(&mut msg_events);
				}

				// Return error in case higher-API need one
				Err(err)
			},
		}
	}
}

/// Returns (boolean indicating if we should remove the Channel object from memory, a mapped error)
macro_rules! convert_chan_err {
	($self: ident, $err: expr, $short_to_id: expr, $channel: expr, $channel_id: expr) => {
		match $err {
			ChannelError::Ignore(msg) => {
				(false, MsgHandleErrInternal::from_chan_no_close(ChannelError::Ignore(msg), $channel_id.clone()))
			},
			ChannelError::Close(msg) => {
				log_error!($self.logger, "Closing channel {} due to close-required error: {}", log_bytes!($channel_id[..]), msg);
				if let Some(short_id) = $channel.get_short_channel_id() {
					$short_to_id.remove(&short_id);
				}
				let shutdown_res = $channel.force_shutdown(true);
				(true, MsgHandleErrInternal::from_finish_shutdown(msg, *$channel_id, shutdown_res, $self.get_channel_update_for_broadcast(&$channel).ok()))
			},
			ChannelError::CloseDelayBroadcast(msg) => {
				log_error!($self.logger, "Channel {} need to be shutdown but closing transactions not broadcast due to {}", log_bytes!($channel_id[..]), msg);
				if let Some(short_id) = $channel.get_short_channel_id() {
					$short_to_id.remove(&short_id);
				}
				let shutdown_res = $channel.force_shutdown(false);
				(true, MsgHandleErrInternal::from_finish_shutdown(msg, *$channel_id, shutdown_res, $self.get_channel_update_for_broadcast(&$channel).ok()))
			}
		}
	}
}

macro_rules! break_chan_entry {
	($self: ident, $res: expr, $channel_state: expr, $entry: expr) => {
		match $res {
			Ok(res) => res,
			Err(e) => {
				let (drop, res) = convert_chan_err!($self, e, $channel_state.short_to_id, $entry.get_mut(), $entry.key());
				if drop {
					$entry.remove_entry();
				}
				break Err(res);
			}
		}
	}
}

macro_rules! try_chan_entry {
	($self: ident, $res: expr, $channel_state: expr, $entry: expr) => {
		match $res {
			Ok(res) => res,
			Err(e) => {
				let (drop, res) = convert_chan_err!($self, e, $channel_state.short_to_id, $entry.get_mut(), $entry.key());
				if drop {
					$entry.remove_entry();
				}
				return Err(res);
			}
		}
	}
}

macro_rules! handle_monitor_err {
	($self: ident, $err: expr, $channel_state: expr, $entry: expr, $action_type: path, $resend_raa: expr, $resend_commitment: expr) => {
		handle_monitor_err!($self, $err, $channel_state, $entry, $action_type, $resend_raa, $resend_commitment, Vec::new(), Vec::new())
	};
	($self: ident, $err: expr, $short_to_id: expr, $chan: expr, $action_type: path, $resend_raa: expr, $resend_commitment: expr, $failed_forwards: expr, $failed_fails: expr, $chan_id: expr) => {
		match $err {
			ChannelMonitorUpdateErr::PermanentFailure => {
				log_error!($self.logger, "Closing channel {} due to monitor update ChannelMonitorUpdateErr::PermanentFailure", log_bytes!($chan_id[..]));
				if let Some(short_id) = $chan.get_short_channel_id() {
					$short_to_id.remove(&short_id);
				}
				// TODO: $failed_fails is dropped here, which will cause other channels to hit the
				// chain in a confused state! We need to move them into the ChannelMonitor which
				// will be responsible for failing backwards once things confirm on-chain.
				// It's ok that we drop $failed_forwards here - at this point we'd rather they
				// broadcast HTLC-Timeout and pay the associated fees to get their funds back than
				// us bother trying to claim it just to forward on to another peer. If we're
				// splitting hairs we'd prefer to claim payments that were to us, but we haven't
				// given up the preimage yet, so might as well just wait until the payment is
				// retried, avoiding the on-chain fees.
				let res: Result<(), _> = Err(MsgHandleErrInternal::from_finish_shutdown("ChannelMonitor storage failure".to_owned(), *$chan_id,
						$chan.force_shutdown(true), $self.get_channel_update_for_broadcast(&$chan).ok() ));
				(res, true)
			},
			ChannelMonitorUpdateErr::TemporaryFailure => {
				log_info!($self.logger, "Disabling channel {} due to monitor update TemporaryFailure. On restore will send {} and process {} forwards and {} fails",
						log_bytes!($chan_id[..]),
						if $resend_commitment && $resend_raa {
								match $action_type {
									RAACommitmentOrder::CommitmentFirst => { "commitment then RAA" },
									RAACommitmentOrder::RevokeAndACKFirst => { "RAA then commitment" },
								}
							} else if $resend_commitment { "commitment" }
							else if $resend_raa { "RAA" }
							else { "nothing" },
						(&$failed_forwards as &Vec<(PendingHTLCInfo, u64)>).len(),
						(&$failed_fails as &Vec<(HTLCSource, PaymentHash, HTLCFailReason)>).len());
				if !$resend_commitment {
					debug_assert!($action_type == RAACommitmentOrder::RevokeAndACKFirst || !$resend_raa);
				}
				if !$resend_raa {
					debug_assert!($action_type == RAACommitmentOrder::CommitmentFirst || !$resend_commitment);
				}
				$chan.monitor_update_failed($resend_raa, $resend_commitment, $failed_forwards, $failed_fails);
				(Err(MsgHandleErrInternal::from_chan_no_close(ChannelError::Ignore("Failed to update ChannelMonitor".to_owned()), *$chan_id)), false)
			},
		}
	};
	($self: ident, $err: expr, $channel_state: expr, $entry: expr, $action_type: path, $resend_raa: expr, $resend_commitment: expr, $failed_forwards: expr, $failed_fails: expr) => { {
		let (res, drop) = handle_monitor_err!($self, $err, $channel_state.short_to_id, $entry.get_mut(), $action_type, $resend_raa, $resend_commitment, $failed_forwards, $failed_fails, $entry.key());
		if drop {
			$entry.remove_entry();
		}
		res
	} };
}

macro_rules! return_monitor_err {
	($self: ident, $err: expr, $channel_state: expr, $entry: expr, $action_type: path, $resend_raa: expr, $resend_commitment: expr) => {
		return handle_monitor_err!($self, $err, $channel_state, $entry, $action_type, $resend_raa, $resend_commitment);
	};
	($self: ident, $err: expr, $channel_state: expr, $entry: expr, $action_type: path, $resend_raa: expr, $resend_commitment: expr, $failed_forwards: expr, $failed_fails: expr) => {
		return handle_monitor_err!($self, $err, $channel_state, $entry, $action_type, $resend_raa, $resend_commitment, $failed_forwards, $failed_fails);
	}
}

// Does not break in case of TemporaryFailure!
macro_rules! maybe_break_monitor_err {
	($self: ident, $err: expr, $channel_state: expr, $entry: expr, $action_type: path, $resend_raa: expr, $resend_commitment: expr) => {
		match (handle_monitor_err!($self, $err, $channel_state, $entry, $action_type, $resend_raa, $resend_commitment), $err) {
			(e, ChannelMonitorUpdateErr::PermanentFailure) => {
				break e;
			},
			(_, ChannelMonitorUpdateErr::TemporaryFailure) => { },
		}
	}
}

macro_rules! handle_chan_restoration_locked {
	($self: ident, $channel_lock: expr, $channel_state: expr, $channel_entry: expr,
	 $raa: expr, $commitment_update: expr, $order: expr, $chanmon_update: expr,
	 $pending_forwards: expr, $funding_broadcastable: expr, $funding_locked: expr) => { {
		let mut htlc_forwards = None;
		let counterparty_node_id = $channel_entry.get().get_counterparty_node_id();

		let chanmon_update: Option<ChannelMonitorUpdate> = $chanmon_update; // Force type-checking to resolve
		let chanmon_update_is_none = chanmon_update.is_none();
		let res = loop {
			let forwards: Vec<(PendingHTLCInfo, u64)> = $pending_forwards; // Force type-checking to resolve
			if !forwards.is_empty() {
				htlc_forwards = Some(($channel_entry.get().get_short_channel_id().expect("We can't have pending forwards before funding confirmation"),
					$channel_entry.get().get_funding_txo().unwrap(), forwards));
			}

			if chanmon_update.is_some() {
				// On reconnect, we, by definition, only resend a funding_locked if there have been
				// no commitment updates, so the only channel monitor update which could also be
				// associated with a funding_locked would be the funding_created/funding_signed
				// monitor update. That monitor update failing implies that we won't send
				// funding_locked until it's been updated, so we can't have a funding_locked and a
				// monitor update here (so we don't bother to handle it correctly below).
				assert!($funding_locked.is_none());
				// A channel monitor update makes no sense without either a funding_locked or a
				// commitment update to process after it. Since we can't have a funding_locked, we
				// only bother to handle the monitor-update + commitment_update case below.
				assert!($commitment_update.is_some());
			}

			if let Some(msg) = $funding_locked {
				// Similar to the above, this implies that we're letting the funding_locked fly
				// before it should be allowed to.
				assert!(chanmon_update.is_none());
				$channel_state.pending_msg_events.push(events::MessageSendEvent::SendFundingLocked {
					node_id: counterparty_node_id,
					msg,
				});
				if let Some(announcement_sigs) = $self.get_announcement_sigs($channel_entry.get()) {
					$channel_state.pending_msg_events.push(events::MessageSendEvent::SendAnnouncementSignatures {
						node_id: counterparty_node_id,
						msg: announcement_sigs,
					});
				}
				$channel_state.short_to_id.insert($channel_entry.get().get_short_channel_id().unwrap(), $channel_entry.get().channel_id());
			}

			let funding_broadcastable: Option<Transaction> = $funding_broadcastable; // Force type-checking to resolve
			if let Some(monitor_update) = chanmon_update {
				// We only ever broadcast a funding transaction in response to a funding_signed
				// message and the resulting monitor update. Thus, on channel_reestablish
				// message handling we can't have a funding transaction to broadcast. When
				// processing a monitor update finishing resulting in a funding broadcast, we
				// cannot have a second monitor update, thus this case would indicate a bug.
				assert!(funding_broadcastable.is_none());
				// Given we were just reconnected or finished updating a channel monitor, the
				// only case where we can get a new ChannelMonitorUpdate would be if we also
				// have some commitment updates to send as well.
				assert!($commitment_update.is_some());
				if let Err(e) = $self.chain_monitor.update_channel($channel_entry.get().get_funding_txo().unwrap(), monitor_update) {
					// channel_reestablish doesn't guarantee the order it returns is sensical
					// for the messages it returns, but if we're setting what messages to
					// re-transmit on monitor update success, we need to make sure it is sane.
					let mut order = $order;
					if $raa.is_none() {
						order = RAACommitmentOrder::CommitmentFirst;
					}
					break handle_monitor_err!($self, e, $channel_state, $channel_entry, order, $raa.is_some(), true);
				}
			}

			macro_rules! handle_cs { () => {
				if let Some(update) = $commitment_update {
					$channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
						node_id: counterparty_node_id,
						updates: update,
					});
				}
			} }
			macro_rules! handle_raa { () => {
				if let Some(revoke_and_ack) = $raa {
					$channel_state.pending_msg_events.push(events::MessageSendEvent::SendRevokeAndACK {
						node_id: counterparty_node_id,
						msg: revoke_and_ack,
					});
				}
			} }
			match $order {
				RAACommitmentOrder::CommitmentFirst => {
					handle_cs!();
					handle_raa!();
				},
				RAACommitmentOrder::RevokeAndACKFirst => {
					handle_raa!();
					handle_cs!();
				},
			}
			if let Some(tx) = funding_broadcastable {
				log_info!($self.logger, "Broadcasting funding transaction with txid {}", tx.txid());
				$self.tx_broadcaster.broadcast_transaction(&tx);
			}
			break Ok(());
		};

		if chanmon_update_is_none {
			// If there was no ChannelMonitorUpdate, we should never generate an Err in the res loop
			// above. Doing so would imply calling handle_err!() from channel_monitor_updated() which
			// should *never* end up calling back to `chain_monitor.update_channel()`.
			assert!(res.is_ok());
		}

		(htlc_forwards, res, counterparty_node_id)
	} }
}

macro_rules! post_handle_chan_restoration {
	($self: ident, $locked_res: expr) => { {
		let (htlc_forwards, res, counterparty_node_id) = $locked_res;

		let _ = handle_error!($self, res, counterparty_node_id);

		if let Some(forwards) = htlc_forwards {
			$self.forward_htlcs(&mut [forwards][..]);
		}
	} }
}

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<Signer, M, T, K, F, L>
	where M::Target: chain::Watch<Signer>,
        T::Target: BroadcasterInterface,
        K::Target: KeysInterface<Signer = Signer>,
        F::Target: FeeEstimator,
        L::Target: Logger,
{
	/// Constructs a new ChannelManager to hold several channels and route between them.
	///
	/// This is the main "logic hub" for all channel-related actions, and implements
	/// ChannelMessageHandler.
	///
	/// Non-proportional fees are fixed according to our risk using the provided fee estimator.
	///
	/// panics if channel_value_satoshis is >= `MAX_FUNDING_SATOSHIS`!
	///
	/// Users need to notify the new ChannelManager when a new block is connected or
	/// disconnected using its `block_connected` and `block_disconnected` methods, starting
	/// from after `params.latest_hash`.
	pub fn new(fee_est: F, chain_monitor: M, tx_broadcaster: T, logger: L, keys_manager: K, config: UserConfig, params: ChainParameters) -> Self {
		let mut secp_ctx = Secp256k1::new();
		secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());

		ChannelManager {
			default_configuration: config.clone(),
			genesis_hash: genesis_block(params.network).header.block_hash(),
			fee_estimator: fee_est,
			chain_monitor,
			tx_broadcaster,

			best_block: RwLock::new(params.best_block),

			channel_state: Mutex::new(ChannelHolder{
				by_id: HashMap::new(),
				short_to_id: HashMap::new(),
				forward_htlcs: HashMap::new(),
				claimable_htlcs: HashMap::new(),
				pending_msg_events: Vec::new(),
			}),
			pending_inbound_payments: Mutex::new(HashMap::new()),
			pending_outbound_payments: Mutex::new(HashSet::new()),

			our_network_key: keys_manager.get_node_secret(),
			our_network_pubkey: PublicKey::from_secret_key(&secp_ctx, &keys_manager.get_node_secret()),
			secp_ctx,

			last_node_announcement_serial: AtomicUsize::new(0),
			highest_seen_timestamp: AtomicUsize::new(0),

			per_peer_state: RwLock::new(HashMap::new()),

			pending_events: Mutex::new(Vec::new()),
			pending_background_events: Mutex::new(Vec::new()),
			total_consistency_lock: RwLock::new(()),
			persistence_notifier: PersistenceNotifier::new(),

			keys_manager,

			logger,
		}
	}

	/// Gets the current configuration applied to all new channels,  as
	pub fn get_current_default_configuration(&self) -> &UserConfig {
		&self.default_configuration
	}

	/// Creates a new outbound channel to the given remote node and with the given value.
	///
	/// user_id will be provided back as user_channel_id in FundingGenerationReady events to allow
	/// tracking of which events correspond with which create_channel call. Note that the
	/// user_channel_id defaults to 0 for inbound channels, so you may wish to avoid using 0 for
	/// user_id here. user_id has no meaning inside of LDK, it is simply copied to events and
	/// otherwise ignored.
	///
	/// If successful, will generate a SendOpenChannel message event, so you should probably poll
	/// PeerManager::process_events afterwards.
	///
	/// Raises APIError::APIMisuseError when channel_value_satoshis > 2**24 or push_msat is
	/// greater than channel_value_satoshis * 1k or channel_value_satoshis is < 1000.
	///
	/// Note that we do not check if you are currently connected to the given peer. If no
	/// connection is available, the outbound `open_channel` message may fail to send, resulting in
	/// the channel eventually being silently forgotten.
	pub fn create_channel(&self, their_network_key: PublicKey, channel_value_satoshis: u64, push_msat: u64, user_id: u64, override_config: Option<UserConfig>) -> Result<(), APIError> {
		if channel_value_satoshis < 1000 {
			return Err(APIError::APIMisuseError { err: format!("Channel value must be at least 1000 satoshis. It was {}", channel_value_satoshis) });
		}

		let config = if override_config.is_some() { override_config.as_ref().unwrap() } else { &self.default_configuration };
		let channel = Channel::new_outbound(&self.fee_estimator, &self.keys_manager, their_network_key, channel_value_satoshis, push_msat, user_id, config)?;
		let res = channel.get_open_channel(self.genesis_hash.clone());

		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		// We want to make sure the lock is actually acquired by PersistenceNotifierGuard.
		debug_assert!(&self.total_consistency_lock.try_write().is_err());

		let mut channel_state = self.channel_state.lock().unwrap();
		match channel_state.by_id.entry(channel.channel_id()) {
			hash_map::Entry::Occupied(_) => {
				if cfg!(feature = "fuzztarget") {
					return Err(APIError::APIMisuseError { err: "Fuzzy bad RNG".to_owned() });
				} else {
					panic!("RNG is bad???");
				}
			},
			hash_map::Entry::Vacant(entry) => { entry.insert(channel); }
		}
		channel_state.pending_msg_events.push(events::MessageSendEvent::SendOpenChannel {
			node_id: their_network_key,
			msg: res,
		});
		Ok(())
	}

	fn list_channels_with_filter<Fn: FnMut(&(&[u8; 32], &Channel<Signer>)) -> bool>(&self, f: Fn) -> Vec<ChannelDetails> {
		let mut res = Vec::new();
		{
			let channel_state = self.channel_state.lock().unwrap();
			res.reserve(channel_state.by_id.len());
			for (channel_id, channel) in channel_state.by_id.iter().filter(f) {
				let (inbound_capacity_msat, outbound_capacity_msat) = channel.get_inbound_outbound_available_balance_msat();
				let (to_remote_reserve_satoshis, to_self_reserve_satoshis) =
					channel.get_holder_counterparty_selected_channel_reserve_satoshis();
				res.push(ChannelDetails {
					channel_id: (*channel_id).clone(),
					counterparty: ChannelCounterparty {
						node_id: channel.get_counterparty_node_id(),
						features: InitFeatures::empty(),
						unspendable_punishment_reserve: to_remote_reserve_satoshis,
						forwarding_info: channel.counterparty_forwarding_info(),
					},
					funding_txo: channel.get_funding_txo(),
					short_channel_id: channel.get_short_channel_id(),
					channel_value_satoshis: channel.get_value_satoshis(),
					unspendable_punishment_reserve: to_self_reserve_satoshis,
					inbound_capacity_msat,
					outbound_capacity_msat,
					user_id: channel.get_user_id(),
					confirmations_required: channel.minimum_depth(),
					force_close_spend_delay: channel.get_counterparty_selected_contest_delay(),
					is_outbound: channel.is_outbound(),
					is_funding_locked: channel.is_usable(),
					is_usable: channel.is_live(),
					is_public: channel.should_announce(),
				});
			}
		}
		let per_peer_state = self.per_peer_state.read().unwrap();
		for chan in res.iter_mut() {
			if let Some(peer_state) = per_peer_state.get(&chan.counterparty.node_id) {
				chan.counterparty.features = peer_state.lock().unwrap().latest_features.clone();
			}
		}
		res
	}

	/// Gets the list of open channels, in random order. See ChannelDetail field documentation for
	/// more information.
	pub fn list_channels(&self) -> Vec<ChannelDetails> {
		self.list_channels_with_filter(|_| true)
	}

	/// Gets the list of usable channels, in random order. Useful as an argument to
	/// get_route to ensure non-announced channels are used.
	///
	/// These are guaranteed to have their [`ChannelDetails::is_usable`] value set to true, see the
	/// documentation for [`ChannelDetails::is_usable`] for more info on exactly what the criteria
	/// are.
	pub fn list_usable_channels(&self) -> Vec<ChannelDetails> {
		// Note we use is_live here instead of usable which leads to somewhat confused
		// internal/external nomenclature, but that's ok cause that's probably what the user
		// really wanted anyway.
		self.list_channels_with_filter(|&(_, ref channel)| channel.is_live())
	}

	/// Begins the process of closing a channel. After this call (plus some timeout), no new HTLCs
	/// will be accepted on the given channel, and after additional timeout/the closing of all
	/// pending HTLCs, the channel will be closed on chain.
	///
	/// May generate a SendShutdown message event on success, which should be relayed.
	pub fn close_channel(&self, channel_id: &[u8; 32]) -> Result<(), APIError> {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		let (mut failed_htlcs, chan_option) = {
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;
			match channel_state.by_id.entry(channel_id.clone()) {
				hash_map::Entry::Occupied(mut chan_entry) => {
					let (shutdown_msg, failed_htlcs) = chan_entry.get_mut().get_shutdown()?;
					channel_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
						node_id: chan_entry.get().get_counterparty_node_id(),
						msg: shutdown_msg
					});
					if chan_entry.get().is_shutdown() {
						if let Some(short_id) = chan_entry.get().get_short_channel_id() {
							channel_state.short_to_id.remove(&short_id);
						}
						(failed_htlcs, Some(chan_entry.remove_entry().1))
					} else { (failed_htlcs, None) }
				},
				hash_map::Entry::Vacant(_) => return Err(APIError::ChannelUnavailable{err: "No such channel".to_owned()})
			}
		};
		for htlc_source in failed_htlcs.drain(..) {
			self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() });
		}
		let chan_update = if let Some(chan) = chan_option {
			self.get_channel_update_for_broadcast(&chan).ok()
		} else { None };

		if let Some(update) = chan_update {
			let mut channel_state = self.channel_state.lock().unwrap();
			channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
				msg: update
			});
		}

		Ok(())
	}

	#[inline]
	fn finish_force_close_channel(&self, shutdown_res: ShutdownResult) {
		let (monitor_update_option, mut failed_htlcs) = shutdown_res;
		log_debug!(self.logger, "Finishing force-closure of channel with {} HTLCs to fail", failed_htlcs.len());
		for htlc_source in failed_htlcs.drain(..) {
			self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() });
		}
		if let Some((funding_txo, monitor_update)) = monitor_update_option {
			// There isn't anything we can do if we get an update failure - we're already
			// force-closing. The monitor update on the required in-memory copy should broadcast
			// the latest local state, which is the best we can do anyway. Thus, it is safe to
			// ignore the result here.
			let _ = self.chain_monitor.update_channel(funding_txo, monitor_update);
		}
	}

	fn force_close_channel_with_peer(&self, channel_id: &[u8; 32], peer_node_id: Option<&PublicKey>) -> Result<PublicKey, APIError> {
		let mut chan = {
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;
			if let hash_map::Entry::Occupied(chan) = channel_state.by_id.entry(channel_id.clone()) {
				if let Some(node_id) = peer_node_id {
					if chan.get().get_counterparty_node_id() != *node_id {
						return Err(APIError::ChannelUnavailable{err: "No such channel".to_owned()});
					}
				}
				if let Some(short_id) = chan.get().get_short_channel_id() {
					channel_state.short_to_id.remove(&short_id);
				}
				chan.remove_entry().1
			} else {
				return Err(APIError::ChannelUnavailable{err: "No such channel".to_owned()});
			}
		};
		log_error!(self.logger, "Force-closing channel {}", log_bytes!(channel_id[..]));
		self.finish_force_close_channel(chan.force_shutdown(true));
		if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
			let mut channel_state = self.channel_state.lock().unwrap();
			channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
				msg: update
			});
		}

		Ok(chan.get_counterparty_node_id())
	}

	/// Force closes a channel, immediately broadcasting the latest local commitment transaction to
	/// the chain and rejecting new HTLCs on the given channel. Fails if channel_id is unknown to the manager.
	pub fn force_close_channel(&self, channel_id: &[u8; 32]) -> Result<(), APIError> {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		match self.force_close_channel_with_peer(channel_id, None) {
			Ok(counterparty_node_id) => {
				self.channel_state.lock().unwrap().pending_msg_events.push(
					events::MessageSendEvent::HandleError {
						node_id: counterparty_node_id,
						action: msgs::ErrorAction::SendErrorMessage {
							msg: msgs::ErrorMessage { channel_id: *channel_id, data: "Channel force-closed".to_owned() }
						},
					}
				);
				Ok(())
			},
			Err(e) => Err(e)
		}
	}

	/// Force close all channels, immediately broadcasting the latest local commitment transaction
	/// for each to the chain and rejecting new HTLCs on each.
	pub fn force_close_all_channels(&self) {
		for chan in self.list_channels() {
			let _ = self.force_close_channel(&chan.channel_id);
		}
	}

	fn decode_update_add_htlc_onion(&self, msg: &msgs::UpdateAddHTLC) -> (PendingHTLCStatus, MutexGuard<ChannelHolder<Signer>>) {
		macro_rules! return_malformed_err {
			($msg: expr, $err_code: expr) => {
				{
					log_info!(self.logger, "Failed to accept/forward incoming HTLC: {}", $msg);
					return (PendingHTLCStatus::Fail(HTLCFailureMsg::Malformed(msgs::UpdateFailMalformedHTLC {
						channel_id: msg.channel_id,
						htlc_id: msg.htlc_id,
						sha256_of_onion: Sha256::hash(&msg.onion_routing_packet.hop_data).into_inner(),
						failure_code: $err_code,
					})), self.channel_state.lock().unwrap());
				}
			}
		}

		if let Err(_) = msg.onion_routing_packet.public_key {
			return_malformed_err!("invalid ephemeral pubkey", 0x8000 | 0x4000 | 6);
		}

		let shared_secret = {
			let mut arr = [0; 32];
			arr.copy_from_slice(&SharedSecret::new(&msg.onion_routing_packet.public_key.unwrap(), &self.our_network_key)[..]);
			arr
		};
		let (rho, mu) = onion_utils::gen_rho_mu_from_shared_secret(&shared_secret);

		if msg.onion_routing_packet.version != 0 {
			//TODO: Spec doesn't indicate if we should only hash hop_data here (and in other
			//sha256_of_onion error data packets), or the entire onion_routing_packet. Either way,
			//the hash doesn't really serve any purpose - in the case of hashing all data, the
			//receiving node would have to brute force to figure out which version was put in the
			//packet by the node that send us the message, in the case of hashing the hop_data, the
			//node knows the HMAC matched, so they already know what is there...
			return_malformed_err!("Unknown onion packet version", 0x8000 | 0x4000 | 4);
		}

		let mut hmac = HmacEngine::<Sha256>::new(&mu);
		hmac.input(&msg.onion_routing_packet.hop_data);
		hmac.input(&msg.payment_hash.0[..]);
		if !fixed_time_eq(&Hmac::from_engine(hmac).into_inner(), &msg.onion_routing_packet.hmac) {
			return_malformed_err!("HMAC Check failed", 0x8000 | 0x4000 | 5);
		}

		let mut channel_state = None;
		macro_rules! return_err {
			($msg: expr, $err_code: expr, $data: expr) => {
				{
					log_info!(self.logger, "Failed to accept/forward incoming HTLC: {}", $msg);
					if channel_state.is_none() {
						channel_state = Some(self.channel_state.lock().unwrap());
					}
					return (PendingHTLCStatus::Fail(HTLCFailureMsg::Relay(msgs::UpdateFailHTLC {
						channel_id: msg.channel_id,
						htlc_id: msg.htlc_id,
						reason: onion_utils::build_first_hop_failure_packet(&shared_secret, $err_code, $data),
					})), channel_state.unwrap());
				}
			}
		}

		let mut chacha = ChaCha20::new(&rho, &[0u8; 8]);
		let mut chacha_stream = ChaChaReader { chacha: &mut chacha, read: Cursor::new(&msg.onion_routing_packet.hop_data[..]) };
		let (next_hop_data, next_hop_hmac) = {
			match msgs::OnionHopData::read(&mut chacha_stream) {
				Err(err) => {
					let error_code = match err {
						msgs::DecodeError::UnknownVersion => 0x4000 | 1, // unknown realm byte
						msgs::DecodeError::UnknownRequiredFeature|
						msgs::DecodeError::InvalidValue|
						msgs::DecodeError::ShortRead => 0x4000 | 22, // invalid_onion_payload
						_ => 0x2000 | 2, // Should never happen
					};
					return_err!("Unable to decode our hop data", error_code, &[0;0]);
				},
				Ok(msg) => {
					let mut hmac = [0; 32];
					if let Err(_) = chacha_stream.read_exact(&mut hmac[..]) {
						return_err!("Unable to decode hop data", 0x4000 | 22, &[0;0]);
					}
					(msg, hmac)
				},
			}
		};

		let pending_forward_info = if next_hop_hmac == [0; 32] {
				#[cfg(test)]
				{
					// In tests, make sure that the initial onion pcket data is, at least, non-0.
					// We could do some fancy randomness test here, but, ehh, whatever.
					// This checks for the issue where you can calculate the path length given the
					// onion data as all the path entries that the originator sent will be here
					// as-is (and were originally 0s).
					// Of course reverse path calculation is still pretty easy given naive routing
					// algorithms, but this fixes the most-obvious case.
					let mut next_bytes = [0; 32];
					chacha_stream.read_exact(&mut next_bytes).unwrap();
					assert_ne!(next_bytes[..], [0; 32][..]);
					chacha_stream.read_exact(&mut next_bytes).unwrap();
					assert_ne!(next_bytes[..], [0; 32][..]);
				}

				// OUR PAYMENT!
				// final_expiry_too_soon
				// We have to have some headroom to broadcast on chain if we have the preimage, so make sure we have at least
				// HTLC_FAIL_BACK_BUFFER blocks to go.
				// Also, ensure that, in the case of an unknown payment hash, our payment logic has enough time to fail the HTLC backward
				// before our onchain logic triggers a channel closure (see HTLC_FAIL_BACK_BUFFER rational).
				if (msg.cltv_expiry as u64) <= self.best_block.read().unwrap().height() as u64 + HTLC_FAIL_BACK_BUFFER as u64 + 1 {
					return_err!("The final CLTV expiry is too soon to handle", 17, &[0;0]);
				}
				// final_incorrect_htlc_amount
				if next_hop_data.amt_to_forward > msg.amount_msat {
					return_err!("Upstream node sent less than we were supposed to receive in payment", 19, &byte_utils::be64_to_array(msg.amount_msat));
				}
				// final_incorrect_cltv_expiry
				if next_hop_data.outgoing_cltv_value != msg.cltv_expiry {
					return_err!("Upstream node set CLTV to the wrong value", 18, &byte_utils::be32_to_array(msg.cltv_expiry));
				}

				let payment_data = match next_hop_data.format {
					msgs::OnionHopDataFormat::Legacy { .. } => None,
					msgs::OnionHopDataFormat::NonFinalNode { .. } => return_err!("Got non final data with an HMAC of 0", 0x4000 | 22, &[0;0]),
					msgs::OnionHopDataFormat::FinalNode { payment_data } => payment_data,
				};

				if payment_data.is_none() {
					return_err!("We require payment_secrets", 0x4000|0x2000|3, &[0;0]);
				}

				// Note that we could obviously respond immediately with an update_fulfill_htlc
				// message, however that would leak that we are the recipient of this payment, so
				// instead we stay symmetric with the forwarding case, only responding (after a
				// delay) once they've send us a commitment_signed!

				PendingHTLCStatus::Forward(PendingHTLCInfo {
					routing: PendingHTLCRouting::Receive {
						payment_data: payment_data.unwrap(),
						incoming_cltv_expiry: msg.cltv_expiry,
					},
					payment_hash: msg.payment_hash.clone(),
					incoming_shared_secret: shared_secret,
					amt_to_forward: next_hop_data.amt_to_forward,
					outgoing_cltv_value: next_hop_data.outgoing_cltv_value,
				})
			} else {
				let mut new_packet_data = [0; 20*65];
				let read_pos = chacha_stream.read(&mut new_packet_data).unwrap();
				#[cfg(debug_assertions)]
				{
					// Check two things:
					// a) that the behavior of our stream here will return Ok(0) even if the TLV
					//    read above emptied out our buffer and the unwrap() wont needlessly panic
					// b) that we didn't somehow magically end up with extra data.
					let mut t = [0; 1];
					debug_assert!(chacha_stream.read(&mut t).unwrap() == 0);
				}
				// Once we've emptied the set of bytes our peer gave us, encrypt 0 bytes until we
				// fill the onion hop data we'll forward to our next-hop peer.
				chacha_stream.chacha.process_in_place(&mut new_packet_data[read_pos..]);

				let mut new_pubkey = msg.onion_routing_packet.public_key.unwrap();

				let blinding_factor = {
					let mut sha = Sha256::engine();
					sha.input(&new_pubkey.serialize()[..]);
					sha.input(&shared_secret);
					Sha256::from_engine(sha).into_inner()
				};

				let public_key = if let Err(e) = new_pubkey.mul_assign(&self.secp_ctx, &blinding_factor[..]) {
					Err(e)
				} else { Ok(new_pubkey) };

				let outgoing_packet = msgs::OnionPacket {
					version: 0,
					public_key,
					hop_data: new_packet_data,
					hmac: next_hop_hmac.clone(),
				};

				let short_channel_id = match next_hop_data.format {
					msgs::OnionHopDataFormat::Legacy { short_channel_id } => short_channel_id,
					msgs::OnionHopDataFormat::NonFinalNode { short_channel_id } => short_channel_id,
					msgs::OnionHopDataFormat::FinalNode { .. } => {
						return_err!("Final Node OnionHopData provided for us as an intermediary node", 0x4000 | 22, &[0;0]);
					},
				};

				PendingHTLCStatus::Forward(PendingHTLCInfo {
					routing: PendingHTLCRouting::Forward {
						onion_packet: outgoing_packet,
						short_channel_id,
					},
					payment_hash: msg.payment_hash.clone(),
					incoming_shared_secret: shared_secret,
					amt_to_forward: next_hop_data.amt_to_forward,
					outgoing_cltv_value: next_hop_data.outgoing_cltv_value,
				})
			};

		channel_state = Some(self.channel_state.lock().unwrap());
		if let &PendingHTLCStatus::Forward(PendingHTLCInfo { ref routing, ref amt_to_forward, ref outgoing_cltv_value, .. }) = &pending_forward_info {
			// If short_channel_id is 0 here, we'll reject the HTLC as there cannot be a channel
			// with a short_channel_id of 0. This is important as various things later assume
			// short_channel_id is non-0 in any ::Forward.
			if let &PendingHTLCRouting::Forward { ref short_channel_id, .. } = routing {
				let id_option = channel_state.as_ref().unwrap().short_to_id.get(&short_channel_id).cloned();
				if let Some((err, code, chan_update)) = loop {
					let forwarding_id = match id_option {
						None => { // unknown_next_peer
							break Some(("Don't have available channel for forwarding as requested.", 0x4000 | 10, None));
						},
						Some(id) => id.clone(),
					};

					let chan = channel_state.as_mut().unwrap().by_id.get_mut(&forwarding_id).unwrap();

					if !chan.should_announce() && !self.default_configuration.accept_forwards_to_priv_channels {
						// Note that the behavior here should be identical to the above block - we
						// should NOT reveal the existence or non-existence of a private channel if
						// we don't allow forwards outbound over them.
						break Some(("Don't have available channel for forwarding as requested.", 0x4000 | 10, None));
					}

					// Note that we could technically not return an error yet here and just hope
					// that the connection is reestablished or monitor updated by the time we get
					// around to doing the actual forward, but better to fail early if we can and
					// hopefully an attacker trying to path-trace payments cannot make this occur
					// on a small/per-node/per-channel scale.
					if !chan.is_live() { // channel_disabled
						break Some(("Forwarding channel is not in a ready state.", 0x1000 | 20, Some(self.get_channel_update_for_unicast(chan).unwrap())));
					}
					if *amt_to_forward < chan.get_counterparty_htlc_minimum_msat() { // amount_below_minimum
						break Some(("HTLC amount was below the htlc_minimum_msat", 0x1000 | 11, Some(self.get_channel_update_for_unicast(chan).unwrap())));
					}
					let fee = amt_to_forward.checked_mul(chan.get_fee_proportional_millionths() as u64)
						.and_then(|prop_fee| { (prop_fee / 1000000)
						.checked_add(chan.get_outbound_forwarding_fee_base_msat() as u64) });
					if fee.is_none() || msg.amount_msat < fee.unwrap() || (msg.amount_msat - fee.unwrap()) < *amt_to_forward { // fee_insufficient
						break Some(("Prior hop has deviated from specified fees parameters or origin node has obsolete ones", 0x1000 | 12, Some(self.get_channel_update_for_unicast(chan).unwrap())));
					}
					if (msg.cltv_expiry as u64) < (*outgoing_cltv_value) as u64 + chan.get_cltv_expiry_delta() as u64 { // incorrect_cltv_expiry
						break Some(("Forwarding node has tampered with the intended HTLC values or origin node has an obsolete cltv_expiry_delta", 0x1000 | 13, Some(self.get_channel_update_for_unicast(chan).unwrap())));
					}
					let cur_height = self.best_block.read().unwrap().height() + 1;
					// Theoretically, channel counterparty shouldn't send us a HTLC expiring now, but we want to be robust wrt to counterparty
					// packet sanitization (see HTLC_FAIL_BACK_BUFFER rational)
					if msg.cltv_expiry <= cur_height + HTLC_FAIL_BACK_BUFFER as u32 { // expiry_too_soon
						break Some(("CLTV expiry is too close", 0x1000 | 14, Some(self.get_channel_update_for_unicast(chan).unwrap())));
					}
					if msg.cltv_expiry > cur_height + CLTV_FAR_FAR_AWAY as u32 { // expiry_too_far
						break Some(("CLTV expiry is too far in the future", 21, None));
					}
					// In theory, we would be safe against unintentional channel-closure, if we only required a margin of LATENCY_GRACE_PERIOD_BLOCKS.
					// But, to be safe against policy reception, we use a longer delay.
					if (*outgoing_cltv_value) as u64 <= (cur_height + HTLC_FAIL_BACK_BUFFER) as u64 {
						break Some(("Outgoing CLTV value is too soon", 0x1000 | 14, Some(self.get_channel_update_for_unicast(chan).unwrap())));
					}

					break None;
				}
				{
					let mut res = Vec::with_capacity(8 + 128);
					if let Some(chan_update) = chan_update {
						if code == 0x1000 | 11 || code == 0x1000 | 12 {
							res.extend_from_slice(&byte_utils::be64_to_array(msg.amount_msat));
						}
						else if code == 0x1000 | 13 {
							res.extend_from_slice(&byte_utils::be32_to_array(msg.cltv_expiry));
						}
						else if code == 0x1000 | 20 {
							// TODO: underspecified, follow https://github.com/lightningnetwork/lightning-rfc/issues/791
							res.extend_from_slice(&byte_utils::be16_to_array(0));
						}
						res.extend_from_slice(&chan_update.encode_with_len()[..]);
					}
					return_err!(err, code, &res[..]);
				}
			}
		}

		(pending_forward_info, channel_state.unwrap())
	}

	/// Gets the current channel_update for the given channel. This first checks if the channel is
	/// public, and thus should be called whenever the result is going to be passed out in a
	/// [`MessageSendEvent::BroadcastChannelUpdate`] event.
	///
	/// May be called with channel_state already locked!
	fn get_channel_update_for_broadcast(&self, chan: &Channel<Signer>) -> Result<msgs::ChannelUpdate, LightningError> {
		if !chan.should_announce() {
			return Err(LightningError {
				err: "Cannot broadcast a channel_update for a private channel".to_owned(),
				action: msgs::ErrorAction::IgnoreError
			});
		}
		log_trace!(self.logger, "Attempting to generate broadcast channel update for channel {}", log_bytes!(chan.channel_id()));
		self.get_channel_update_for_unicast(chan)
	}

	/// Gets the current channel_update for the given channel. This does not check if the channel
	/// is public (only returning an Err if the channel does not yet have an assigned short_id),
	/// and thus MUST NOT be called unless the recipient of the resulting message has already
	/// provided evidence that they know about the existence of the channel.
	/// May be called with channel_state already locked!
	fn get_channel_update_for_unicast(&self, chan: &Channel<Signer>) -> Result<msgs::ChannelUpdate, LightningError> {
		log_trace!(self.logger, "Attempting to generate channel update for channel {}", log_bytes!(chan.channel_id()));
		let short_channel_id = match chan.get_short_channel_id() {
			None => return Err(LightningError{err: "Channel not yet established".to_owned(), action: msgs::ErrorAction::IgnoreError}),
			Some(id) => id,
		};

		let were_node_one = PublicKey::from_secret_key(&self.secp_ctx, &self.our_network_key).serialize()[..] < chan.get_counterparty_node_id().serialize()[..];

		let unsigned = msgs::UnsignedChannelUpdate {
			chain_hash: self.genesis_hash,
			short_channel_id,
			timestamp: chan.get_update_time_counter(),
			flags: (!were_node_one) as u8 | ((!chan.is_live() as u8) << 1),
			cltv_expiry_delta: chan.get_cltv_expiry_delta(),
			htlc_minimum_msat: chan.get_counterparty_htlc_minimum_msat(),
			htlc_maximum_msat: OptionalField::Present(chan.get_announced_htlc_max_msat()),
			fee_base_msat: chan.get_outbound_forwarding_fee_base_msat(),
			fee_proportional_millionths: chan.get_fee_proportional_millionths(),
			excess_data: Vec::new(),
		};

		let msg_hash = Sha256dHash::hash(&unsigned.encode()[..]);
		let sig = self.secp_ctx.sign(&hash_to_message!(&msg_hash[..]), &self.our_network_key);

		Ok(msgs::ChannelUpdate {
			signature: sig,
			contents: unsigned
		})
	}

	// Only public for testing, this should otherwise never be called direcly
	pub(crate) fn send_payment_along_path(&self, path: &Vec<RouteHop>, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>, total_value: u64, cur_height: u32) -> Result<(), APIError> {
		log_trace!(self.logger, "Attempting to send payment for path with next hop {}", path.first().unwrap().short_channel_id);
		let prng_seed = self.keys_manager.get_secure_random_bytes();
		let session_priv_bytes = self.keys_manager.get_secure_random_bytes();
		let session_priv = SecretKey::from_slice(&session_priv_bytes[..]).expect("RNG is busted");

		let onion_keys = onion_utils::construct_onion_keys(&self.secp_ctx, &path, &session_priv)
			.map_err(|_| APIError::RouteError{err: "Pubkey along hop was maliciously selected"})?;
		let (onion_payloads, htlc_msat, htlc_cltv) = onion_utils::build_onion_payloads(path, total_value, payment_secret, cur_height)?;
		if onion_utils::route_size_insane(&onion_payloads) {
			return Err(APIError::RouteError{err: "Route size too large considering onion data"});
		}
		let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, prng_seed, payment_hash);

		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		assert!(self.pending_outbound_payments.lock().unwrap().insert(session_priv_bytes));

		let err: Result<(), _> = loop {
			let mut channel_lock = self.channel_state.lock().unwrap();
			let id = match channel_lock.short_to_id.get(&path.first().unwrap().short_channel_id) {
				None => return Err(APIError::ChannelUnavailable{err: "No channel available with first hop!".to_owned()}),
				Some(id) => id.clone(),
			};

			let channel_state = &mut *channel_lock;
			if let hash_map::Entry::Occupied(mut chan) = channel_state.by_id.entry(id) {
				match {
					if chan.get().get_counterparty_node_id() != path.first().unwrap().pubkey {
						return Err(APIError::RouteError{err: "Node ID mismatch on first hop!"});
					}
					if !chan.get().is_live() {
						return Err(APIError::ChannelUnavailable{err: "Peer for first hop currently disconnected/pending monitor update!".to_owned()});
					}
					break_chan_entry!(self, chan.get_mut().send_htlc_and_commit(htlc_msat, payment_hash.clone(), htlc_cltv, HTLCSource::OutboundRoute {
						path: path.clone(),
						session_priv: session_priv.clone(),
						first_hop_htlc_msat: htlc_msat,
					}, onion_packet, &self.logger), channel_state, chan)
				} {
					Some((update_add, commitment_signed, monitor_update)) => {
						if let Err(e) = self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), monitor_update) {
							maybe_break_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::CommitmentFirst, false, true);
							// Note that MonitorUpdateFailed here indicates (per function docs)
							// that we will resend the commitment update once monitor updating
							// is restored. Therefore, we must return an error indicating that
							// it is unsafe to retry the payment wholesale, which we do in the
							// send_payment check for MonitorUpdateFailed, below.
							return Err(APIError::MonitorUpdateFailed);
						}

						log_debug!(self.logger, "Sending payment along path resulted in a commitment_signed for channel {}", log_bytes!(chan.get().channel_id()));
						channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
							node_id: path.first().unwrap().pubkey,
							updates: msgs::CommitmentUpdate {
								update_add_htlcs: vec![update_add],
								update_fulfill_htlcs: Vec::new(),
								update_fail_htlcs: Vec::new(),
								update_fail_malformed_htlcs: Vec::new(),
								update_fee: None,
								commitment_signed,
							},
						});
					},
					None => {},
				}
			} else { unreachable!(); }
			return Ok(());
		};

		match handle_error!(self, err, path.first().unwrap().pubkey) {
			Ok(_) => unreachable!(),
			Err(e) => {
				Err(APIError::ChannelUnavailable { err: e.err })
			},
		}
	}

	/// Sends a payment along a given route.
	///
	/// Value parameters are provided via the last hop in route, see documentation for RouteHop
	/// fields for more info.
	///
	/// Note that if the payment_hash already exists elsewhere (eg you're sending a duplicative
	/// payment), we don't do anything to stop you! We always try to ensure that if the provided
	/// next hop knows the preimage to payment_hash they can claim an additional amount as
	/// specified in the last hop in the route! Thus, you should probably do your own
	/// payment_preimage tracking (which you should already be doing as they represent "proof of
	/// payment") and prevent double-sends yourself.
	///
	/// May generate SendHTLCs message(s) event on success, which should be relayed.
	///
	/// Each path may have a different return value, and PaymentSendValue may return a Vec with
	/// each entry matching the corresponding-index entry in the route paths, see
	/// PaymentSendFailure for more info.
	///
	/// In general, a path may raise:
	///  * APIError::RouteError when an invalid route or forwarding parameter (cltv_delta, fee,
	///    node public key) is specified.
	///  * APIError::ChannelUnavailable if the next-hop channel is not available for updates
	///    (including due to previous monitor update failure or new permanent monitor update
	///    failure).
	///  * APIError::MonitorUpdateFailed if a new monitor update failure prevented sending the
	///    relevant updates.
	///
	/// Note that depending on the type of the PaymentSendFailure the HTLC may have been
	/// irrevocably committed to on our end. In such a case, do NOT retry the payment with a
	/// different route unless you intend to pay twice!
	///
	/// payment_secret is unrelated to payment_hash (or PaymentPreimage) and exists to authenticate
	/// the sender to the recipient and prevent payment-probing (deanonymization) attacks. For
	/// newer nodes, it will be provided to you in the invoice. If you do not have one, the Route
	/// must not contain multiple paths as multi-path payments require a recipient-provided
	/// payment_secret.
	/// If a payment_secret *is* provided, we assume that the invoice had the payment_secret feature
	/// bit set (either as required or as available). If multiple paths are present in the Route,
	/// we assume the invoice had the basic_mpp feature set.
	pub fn send_payment(&self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>) -> Result<(), PaymentSendFailure> {
		if route.paths.len() < 1 {
			return Err(PaymentSendFailure::ParameterError(APIError::RouteError{err: "There must be at least one path to send over"}));
		}
		if route.paths.len() > 10 {
			// This limit is completely arbitrary - there aren't any real fundamental path-count
			// limits. After we support retrying individual paths we should likely bump this, but
			// for now more than 10 paths likely carries too much one-path failure.
			return Err(PaymentSendFailure::ParameterError(APIError::RouteError{err: "Sending over more than 10 paths is not currently supported"}));
		}
		let mut total_value = 0;
		let our_node_id = self.get_our_node_id();
		let mut path_errs = Vec::with_capacity(route.paths.len());
		'path_check: for path in route.paths.iter() {
			if path.len() < 1 || path.len() > 20 {
				path_errs.push(Err(APIError::RouteError{err: "Path didn't go anywhere/had bogus size"}));
				continue 'path_check;
			}
			for (idx, hop) in path.iter().enumerate() {
				if idx != path.len() - 1 && hop.pubkey == our_node_id {
					path_errs.push(Err(APIError::RouteError{err: "Path went through us but wasn't a simple rebalance loop to us"}));
					continue 'path_check;
				}
			}
			total_value += path.last().unwrap().fee_msat;
			path_errs.push(Ok(()));
		}
		if path_errs.iter().any(|e| e.is_err()) {
			return Err(PaymentSendFailure::PathParameterError(path_errs));
		}

		let cur_height = self.best_block.read().unwrap().height() + 1;
		let mut results = Vec::new();
		for path in route.paths.iter() {
			results.push(self.send_payment_along_path(&path, &payment_hash, payment_secret, total_value, cur_height));
		}
		let mut has_ok = false;
		let mut has_err = false;
		for res in results.iter() {
			if res.is_ok() { has_ok = true; }
			if res.is_err() { has_err = true; }
			if let &Err(APIError::MonitorUpdateFailed) = res {
				// MonitorUpdateFailed is inherently unsafe to retry, so we call it a
				// PartialFailure.
				has_err = true;
				has_ok = true;
				break;
			}
		}
		if has_err && has_ok {
			Err(PaymentSendFailure::PartialFailure(results))
		} else if has_err {
			Err(PaymentSendFailure::AllFailedRetrySafe(results.drain(..).map(|r| r.unwrap_err()).collect()))
		} else {
			Ok(())
		}
	}

	/// Handles the generation of a funding transaction, optionally (for tests) with a function
	/// which checks the correctness of the funding transaction given the associated channel.
	fn funding_transaction_generated_intern<FundingOutput: Fn(&Channel<Signer>, &Transaction) -> Result<OutPoint, APIError>>
			(&self, temporary_channel_id: &[u8; 32], funding_transaction: Transaction, find_funding_output: FundingOutput) -> Result<(), APIError> {
		let (chan, msg) = {
			let (res, chan) = match self.channel_state.lock().unwrap().by_id.remove(temporary_channel_id) {
				Some(mut chan) => {
					let funding_txo = find_funding_output(&chan, &funding_transaction)?;

					(chan.get_outbound_funding_created(funding_transaction, funding_txo, &self.logger)
						.map_err(|e| if let ChannelError::Close(msg) = e {
							MsgHandleErrInternal::from_finish_shutdown(msg, chan.channel_id(), chan.force_shutdown(true), None)
						} else { unreachable!(); })
					, chan)
				},
				None => { return Err(APIError::ChannelUnavailable { err: "No such channel".to_owned() }) },
			};
			match handle_error!(self, res, chan.get_counterparty_node_id()) {
				Ok(funding_msg) => {
					(chan, funding_msg)
				},
				Err(_) => { return Err(APIError::ChannelUnavailable {
					err: "Error deriving keys or signing initial commitment transactions - either our RNG or our counterparty's RNG is broken or the Signer refused to sign".to_owned()
				}) },
			}
		};

		let mut channel_state = self.channel_state.lock().unwrap();
		channel_state.pending_msg_events.push(events::MessageSendEvent::SendFundingCreated {
			node_id: chan.get_counterparty_node_id(),
			msg,
		});
		match channel_state.by_id.entry(chan.channel_id()) {
			hash_map::Entry::Occupied(_) => {
				panic!("Generated duplicate funding txid?");
			},
			hash_map::Entry::Vacant(e) => {
				e.insert(chan);
			}
		}
		Ok(())
	}

	#[cfg(test)]
	pub(crate) fn funding_transaction_generated_unchecked(&self, temporary_channel_id: &[u8; 32], funding_transaction: Transaction, output_index: u16) -> Result<(), APIError> {
		self.funding_transaction_generated_intern(temporary_channel_id, funding_transaction, |_, tx| {
			Ok(OutPoint { txid: tx.txid(), index: output_index })
		})
	}

	/// Call this upon creation of a funding transaction for the given channel.
	///
	/// Returns an [`APIError::APIMisuseError`] if the funding_transaction spent non-SegWit outputs
	/// or if no output was found which matches the parameters in [`Event::FundingGenerationReady`].
	///
	/// Panics if a funding transaction has already been provided for this channel.
	///
	/// May panic if the output found in the funding transaction is duplicative with some other
	/// channel (note that this should be trivially prevented by using unique funding transaction
	/// keys per-channel).
	///
	/// Do NOT broadcast the funding transaction yourself. When we have safely received our
	/// counterparty's signature the funding transaction will automatically be broadcast via the
	/// [`BroadcasterInterface`] provided when this `ChannelManager` was constructed.
	///
	/// Note that this includes RBF or similar transaction replacement strategies - lightning does
	/// not currently support replacing a funding transaction on an existing channel. Instead,
	/// create a new channel with a conflicting funding transaction.
	///
	/// [`Event::FundingGenerationReady`]: crate::util::events::Event::FundingGenerationReady
	pub fn funding_transaction_generated(&self, temporary_channel_id: &[u8; 32], funding_transaction: Transaction) -> Result<(), APIError> {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		for inp in funding_transaction.input.iter() {
			if inp.witness.is_empty() {
				return Err(APIError::APIMisuseError {
					err: "Funding transaction must be fully signed and spend Segwit outputs".to_owned()
				});
			}
		}
		self.funding_transaction_generated_intern(temporary_channel_id, funding_transaction, |chan, tx| {
			let mut output_index = None;
			let expected_spk = chan.get_funding_redeemscript().to_v0_p2wsh();
			for (idx, outp) in tx.output.iter().enumerate() {
				if outp.script_pubkey == expected_spk && outp.value == chan.get_value_satoshis() {
					if output_index.is_some() {
						return Err(APIError::APIMisuseError {
							err: "Multiple outputs matched the expected script and value".to_owned()
						});
					}
					if idx > u16::max_value() as usize {
						return Err(APIError::APIMisuseError {
							err: "Transaction had more than 2^16 outputs, which is not supported".to_owned()
						});
					}
					output_index = Some(idx as u16);
				}
			}
			if output_index.is_none() {
				return Err(APIError::APIMisuseError {
					err: "No output matched the script_pubkey and value in the FundingGenerationReady event".to_owned()
				});
			}
			Ok(OutPoint { txid: tx.txid(), index: output_index.unwrap() })
		})
	}

	fn get_announcement_sigs(&self, chan: &Channel<Signer>) -> Option<msgs::AnnouncementSignatures> {
		if !chan.should_announce() {
			log_trace!(self.logger, "Can't send announcement_signatures for private channel {}", log_bytes!(chan.channel_id()));
			return None
		}

		let (announcement, our_bitcoin_sig) = match chan.get_channel_announcement(self.get_our_node_id(), self.genesis_hash.clone()) {
			Ok(res) => res,
			Err(_) => return None, // Only in case of state precondition violations eg channel is closing
		};
		let msghash = hash_to_message!(&Sha256dHash::hash(&announcement.encode()[..])[..]);
		let our_node_sig = self.secp_ctx.sign(&msghash, &self.our_network_key);

		Some(msgs::AnnouncementSignatures {
			channel_id: chan.channel_id(),
			short_channel_id: chan.get_short_channel_id().unwrap(),
			node_signature: our_node_sig,
			bitcoin_signature: our_bitcoin_sig,
		})
	}

	#[allow(dead_code)]
	// Messages of up to 64KB should never end up more than half full with addresses, as that would
	// be absurd. We ensure this by checking that at least 500 (our stated public contract on when
	// broadcast_node_announcement panics) of the maximum-length addresses would fit in a 64KB
	// message...
	const HALF_MESSAGE_IS_ADDRS: u32 = ::core::u16::MAX as u32 / (NetAddress::MAX_LEN as u32 + 1) / 2;
	#[deny(const_err)]
	#[allow(dead_code)]
	// ...by failing to compile if the number of addresses that would be half of a message is
	// smaller than 500:
	const STATIC_ASSERT: u32 = Self::HALF_MESSAGE_IS_ADDRS - 500;

	/// Regenerates channel_announcements and generates a signed node_announcement from the given
	/// arguments, providing them in corresponding events via
	/// [`get_and_clear_pending_msg_events`], if at least one public channel has been confirmed
	/// on-chain. This effectively re-broadcasts all channel announcements and sends our node
	/// announcement to ensure that the lightning P2P network is aware of the channels we have and
	/// our network addresses.
	///
	/// `rgb` is a node "color" and `alias` is a printable human-readable string to describe this
	/// node to humans. They carry no in-protocol meaning.
	///
	/// `addresses` represent the set (possibly empty) of socket addresses on which this node
	/// accepts incoming connections. These will be included in the node_announcement, publicly
	/// tying these addresses together and to this node. If you wish to preserve user privacy,
	/// addresses should likely contain only Tor Onion addresses.
	///
	/// Panics if `addresses` is absurdly large (more than 500).
	///
	/// [`get_and_clear_pending_msg_events`]: MessageSendEventsProvider::get_and_clear_pending_msg_events
	pub fn broadcast_node_announcement(&self, rgb: [u8; 3], alias: [u8; 32], mut addresses: Vec<NetAddress>) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		if addresses.len() > 500 {
			panic!("More than half the message size was taken up by public addresses!");
		}

		// While all existing nodes handle unsorted addresses just fine, the spec requires that
		// addresses be sorted for future compatibility.
		addresses.sort_by_key(|addr| addr.get_id());

		let announcement = msgs::UnsignedNodeAnnouncement {
			features: NodeFeatures::known(),
			timestamp: self.last_node_announcement_serial.fetch_add(1, Ordering::AcqRel) as u32,
			node_id: self.get_our_node_id(),
			rgb, alias, addresses,
			excess_address_data: Vec::new(),
			excess_data: Vec::new(),
		};
		let msghash = hash_to_message!(&Sha256dHash::hash(&announcement.encode()[..])[..]);
		let node_announce_sig = self.secp_ctx.sign(&msghash, &self.our_network_key);

		let mut channel_state_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_state_lock;

		let mut announced_chans = false;
		for (_, chan) in channel_state.by_id.iter() {
			if let Some(msg) = chan.get_signed_channel_announcement(&self.our_network_key, self.get_our_node_id(), self.genesis_hash.clone()) {
				channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelAnnouncement {
					msg,
					update_msg: match self.get_channel_update_for_broadcast(chan) {
						Ok(msg) => msg,
						Err(_) => continue,
					},
				});
				announced_chans = true;
			} else {
				// If the channel is not public or has not yet reached funding_locked, check the
				// next channel. If we don't yet have any public channels, we'll skip the broadcast
				// below as peers may not accept it without channels on chain first.
			}
		}

		if announced_chans {
			channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastNodeAnnouncement {
				msg: msgs::NodeAnnouncement {
					signature: node_announce_sig,
					contents: announcement
				},
			});
		}
	}

	/// Processes HTLCs which are pending waiting on random forward delay.
	///
	/// Should only really ever be called in response to a PendingHTLCsForwardable event.
	/// Will likely generate further events.
	pub fn process_pending_htlc_forwards(&self) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		let mut new_events = Vec::new();
		let mut failed_forwards = Vec::new();
		let mut handle_errors = Vec::new();
		{
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;

			for (short_chan_id, mut pending_forwards) in channel_state.forward_htlcs.drain() {
				if short_chan_id != 0 {
					let forward_chan_id = match channel_state.short_to_id.get(&short_chan_id) {
						Some(chan_id) => chan_id.clone(),
						None => {
							failed_forwards.reserve(pending_forwards.len());
							for forward_info in pending_forwards.drain(..) {
								match forward_info {
									HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info,
									                           prev_funding_outpoint } => {
										let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
											short_channel_id: prev_short_channel_id,
											outpoint: prev_funding_outpoint,
											htlc_id: prev_htlc_id,
											incoming_packet_shared_secret: forward_info.incoming_shared_secret,
										});
										failed_forwards.push((htlc_source, forward_info.payment_hash,
											HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() }
										));
									},
									HTLCForwardInfo::FailHTLC { .. } => {
										// Channel went away before we could fail it. This implies
										// the channel is now on chain and our counterparty is
										// trying to broadcast the HTLC-Timeout, but that's their
										// problem, not ours.
									}
								}
							}
							continue;
						}
					};
					if let hash_map::Entry::Occupied(mut chan) = channel_state.by_id.entry(forward_chan_id) {
						let mut add_htlc_msgs = Vec::new();
						let mut fail_htlc_msgs = Vec::new();
						for forward_info in pending_forwards.drain(..) {
							match forward_info {
								HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
										routing: PendingHTLCRouting::Forward {
											onion_packet, ..
										}, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value },
										prev_funding_outpoint } => {
									log_trace!(self.logger, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", prev_short_channel_id, log_bytes!(payment_hash.0), short_chan_id);
									let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
										short_channel_id: prev_short_channel_id,
										outpoint: prev_funding_outpoint,
										htlc_id: prev_htlc_id,
										incoming_packet_shared_secret: incoming_shared_secret,
									});
									match chan.get_mut().send_htlc(amt_to_forward, payment_hash, outgoing_cltv_value, htlc_source.clone(), onion_packet) {
										Err(e) => {
											if let ChannelError::Ignore(msg) = e {
												log_trace!(self.logger, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(payment_hash.0), msg);
											} else {
												panic!("Stated return value requirements in send_htlc() were not met");
											}
											let chan_update = self.get_channel_update_for_unicast(chan.get()).unwrap();
											failed_forwards.push((htlc_source, payment_hash,
												HTLCFailReason::Reason { failure_code: 0x1000 | 7, data: chan_update.encode_with_len() }
											));
											continue;
										},
										Ok(update_add) => {
											match update_add {
												Some(msg) => { add_htlc_msgs.push(msg); },
												None => {
													// Nothing to do here...we're waiting on a remote
													// revoke_and_ack before we can add anymore HTLCs. The Channel
													// will automatically handle building the update_add_htlc and
													// commitment_signed messages when we can.
													// TODO: Do some kind of timer to set the channel as !is_live()
													// as we don't really want others relying on us relaying through
													// this channel currently :/.
												}
											}
										}
									}
								},
								HTLCForwardInfo::AddHTLC { .. } => {
									panic!("short_channel_id != 0 should imply any pending_forward entries are of type Forward");
								},
								HTLCForwardInfo::FailHTLC { htlc_id, err_packet } => {
									log_trace!(self.logger, "Failing HTLC back to channel with short id {} (backward HTLC ID {}) after delay", short_chan_id, htlc_id);
									match chan.get_mut().get_update_fail_htlc(htlc_id, err_packet, &self.logger) {
										Err(e) => {
											if let ChannelError::Ignore(msg) = e {
												log_trace!(self.logger, "Failed to fail HTLC with ID {} backwards to short_id {}: {}", htlc_id, short_chan_id, msg);
											} else {
												panic!("Stated return value requirements in get_update_fail_htlc() were not met");
											}
											// fail-backs are best-effort, we probably already have one
											// pending, and if not that's OK, if not, the channel is on
											// the chain and sending the HTLC-Timeout is their problem.
											continue;
										},
										Ok(Some(msg)) => { fail_htlc_msgs.push(msg); },
										Ok(None) => {
											// Nothing to do here...we're waiting on a remote
											// revoke_and_ack before we can update the commitment
											// transaction. The Channel will automatically handle
											// building the update_fail_htlc and commitment_signed
											// messages when we can.
											// We don't need any kind of timer here as they should fail
											// the channel onto the chain if they can't get our
											// update_fail_htlc in time, it's not our problem.
										}
									}
								},
							}
						}

						if !add_htlc_msgs.is_empty() || !fail_htlc_msgs.is_empty() {
							let (commitment_msg, monitor_update) = match chan.get_mut().send_commitment(&self.logger) {
								Ok(res) => res,
								Err(e) => {
									// We surely failed send_commitment due to bad keys, in that case
									// close channel and then send error message to peer.
									let counterparty_node_id = chan.get().get_counterparty_node_id();
									let err: Result<(), _>  = match e {
										ChannelError::Ignore(_) => {
											panic!("Stated return value requirements in send_commitment() were not met");
										},
										ChannelError::Close(msg) => {
											log_trace!(self.logger, "Closing channel {} due to Close-required error: {}", log_bytes!(chan.key()[..]), msg);
											let (channel_id, mut channel) = chan.remove_entry();
											if let Some(short_id) = channel.get_short_channel_id() {
												channel_state.short_to_id.remove(&short_id);
											}
											Err(MsgHandleErrInternal::from_finish_shutdown(msg, channel_id, channel.force_shutdown(true), self.get_channel_update_for_broadcast(&channel).ok()))
										},
										ChannelError::CloseDelayBroadcast(_) => { panic!("Wait is only generated on receipt of channel_reestablish, which is handled by try_chan_entry, we don't bother to support it here"); }
									};
									handle_errors.push((counterparty_node_id, err));
									continue;
								}
							};
							if let Err(e) = self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), monitor_update) {
								handle_errors.push((chan.get().get_counterparty_node_id(), handle_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::CommitmentFirst, false, true)));
								continue;
							}
							log_debug!(self.logger, "Forwarding HTLCs resulted in a commitment update with {} HTLCs added and {} HTLCs failed for channel {}",
								add_htlc_msgs.len(), fail_htlc_msgs.len(), log_bytes!(chan.get().channel_id()));
							channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
								node_id: chan.get().get_counterparty_node_id(),
								updates: msgs::CommitmentUpdate {
									update_add_htlcs: add_htlc_msgs,
									update_fulfill_htlcs: Vec::new(),
									update_fail_htlcs: fail_htlc_msgs,
									update_fail_malformed_htlcs: Vec::new(),
									update_fee: None,
									commitment_signed: commitment_msg,
								},
							});
						}
					} else {
						unreachable!();
					}
				} else {
					for forward_info in pending_forwards.drain(..) {
						match forward_info {
							HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
									routing: PendingHTLCRouting::Receive { payment_data, incoming_cltv_expiry },
									incoming_shared_secret, payment_hash, amt_to_forward, .. },
									prev_funding_outpoint } => {
								let claimable_htlc = ClaimableHTLC {
									prev_hop: HTLCPreviousHopData {
										short_channel_id: prev_short_channel_id,
										outpoint: prev_funding_outpoint,
										htlc_id: prev_htlc_id,
										incoming_packet_shared_secret: incoming_shared_secret,
									},
									value: amt_to_forward,
									payment_data: payment_data.clone(),
									cltv_expiry: incoming_cltv_expiry,
								};

								macro_rules! fail_htlc {
									($htlc: expr) => {
										let mut htlc_msat_height_data = byte_utils::be64_to_array($htlc.value).to_vec();
										htlc_msat_height_data.extend_from_slice(
											&byte_utils::be32_to_array(self.best_block.read().unwrap().height()),
										);
										failed_forwards.push((HTLCSource::PreviousHopData(HTLCPreviousHopData {
												short_channel_id: $htlc.prev_hop.short_channel_id,
												outpoint: prev_funding_outpoint,
												htlc_id: $htlc.prev_hop.htlc_id,
												incoming_packet_shared_secret: $htlc.prev_hop.incoming_packet_shared_secret,
											}), payment_hash,
											HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: htlc_msat_height_data }
										));
									}
								}

								// Check that the payment hash and secret are known. Note that we
								// MUST take care to handle the "unknown payment hash" and
								// "incorrect payment secret" cases here identically or we'd expose
								// that we are the ultimate recipient of the given payment hash.
								// Further, we must not expose whether we have any other HTLCs
								// associated with the same payment_hash pending or not.
								let mut payment_secrets = self.pending_inbound_payments.lock().unwrap();
								match payment_secrets.entry(payment_hash) {
									hash_map::Entry::Vacant(_) => {
										log_trace!(self.logger, "Failing new HTLC with payment_hash {} as we didn't have a corresponding inbound payment.", log_bytes!(payment_hash.0));
										fail_htlc!(claimable_htlc);
									},
									hash_map::Entry::Occupied(inbound_payment) => {
										if inbound_payment.get().payment_secret != payment_data.payment_secret {
											log_trace!(self.logger, "Failing new HTLC with payment_hash {} as it didn't match our expected payment secret.", log_bytes!(payment_hash.0));
											fail_htlc!(claimable_htlc);
										} else if inbound_payment.get().min_value_msat.is_some() && payment_data.total_msat < inbound_payment.get().min_value_msat.unwrap() {
											log_trace!(self.logger, "Failing new HTLC with payment_hash {} as it didn't match our minimum value (had {}, needed {}).",
												log_bytes!(payment_hash.0), payment_data.total_msat, inbound_payment.get().min_value_msat.unwrap());
											fail_htlc!(claimable_htlc);
										} else {
											let mut total_value = 0;
											let htlcs = channel_state.claimable_htlcs.entry(payment_hash)
												.or_insert(Vec::new());
											htlcs.push(claimable_htlc);
											for htlc in htlcs.iter() {
												total_value += htlc.value;
												if htlc.payment_data.total_msat != payment_data.total_msat {
													log_trace!(self.logger, "Failing HTLCs with payment_hash {} as the HTLCs had inconsistent total values (eg {} and {})",
														log_bytes!(payment_hash.0), payment_data.total_msat, htlc.payment_data.total_msat);
													total_value = msgs::MAX_VALUE_MSAT;
												}
												if total_value >= msgs::MAX_VALUE_MSAT { break; }
											}
											if total_value >= msgs::MAX_VALUE_MSAT || total_value > payment_data.total_msat {
												log_trace!(self.logger, "Failing HTLCs with payment_hash {} as the total value {} ran over expected value {} (or HTLCs were inconsistent)",
													log_bytes!(payment_hash.0), total_value, payment_data.total_msat);
												for htlc in htlcs.iter() {
													fail_htlc!(htlc);
												}
											} else if total_value == payment_data.total_msat {
												new_events.push(events::Event::PaymentReceived {
													payment_hash,
													payment_preimage: inbound_payment.get().payment_preimage,
													payment_secret: payment_data.payment_secret,
													amt: total_value,
													user_payment_id: inbound_payment.get().user_payment_id,
												});
												// Only ever generate at most one PaymentReceived
												// per registered payment_hash, even if it isn't
												// claimed.
												inbound_payment.remove_entry();
											} else {
												// Nothing to do - we haven't reached the total
												// payment value yet, wait until we receive more
												// MPP parts.
											}
										}
									},
								};
							},
							HTLCForwardInfo::AddHTLC { .. } => {
								panic!("short_channel_id == 0 should imply any pending_forward entries are of type Receive");
							},
							HTLCForwardInfo::FailHTLC { .. } => {
								panic!("Got pending fail of our own HTLC");
							}
						}
					}
				}
			}
		}

		for (htlc_source, payment_hash, failure_reason) in failed_forwards.drain(..) {
			self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source, &payment_hash, failure_reason);
		}

		for (counterparty_node_id, err) in handle_errors.drain(..) {
			let _ = handle_error!(self, err, counterparty_node_id);
		}

		if new_events.is_empty() { return }
		let mut events = self.pending_events.lock().unwrap();
		events.append(&mut new_events);
	}

	/// Free the background events, generally called from timer_tick_occurred.
	///
	/// Exposed for testing to allow us to process events quickly without generating accidental
	/// BroadcastChannelUpdate events in timer_tick_occurred.
	///
	/// Expects the caller to have a total_consistency_lock read lock.
	fn process_background_events(&self) -> bool {
		let mut background_events = Vec::new();
		mem::swap(&mut *self.pending_background_events.lock().unwrap(), &mut background_events);
		if background_events.is_empty() {
			return false;
		}

		for event in background_events.drain(..) {
			match event {
				BackgroundEvent::ClosingMonitorUpdate((funding_txo, update)) => {
					// The channel has already been closed, so no use bothering to care about the
					// monitor updating completing.
					let _ = self.chain_monitor.update_channel(funding_txo, update);
				},
			}
		}
		true
	}

	#[cfg(any(test, feature = "_test_utils"))]
	/// Process background events, for functional testing
	pub fn test_process_background_events(&self) {
		self.process_background_events();
	}

	/// If a peer is disconnected we mark any channels with that peer as 'disabled'.
	/// After some time, if channels are still disabled we need to broadcast a ChannelUpdate
	/// to inform the network about the uselessness of these channels.
	///
	/// This method handles all the details, and must be called roughly once per minute.
	///
	/// Note that in some rare cases this may generate a `chain::Watch::update_channel` call.
	pub fn timer_tick_occurred(&self) {
		PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
			let mut should_persist = NotifyOption::SkipPersist;
			if self.process_background_events() { should_persist = NotifyOption::DoPersist; }

			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;
			for (_, chan) in channel_state.by_id.iter_mut() {
				match chan.channel_update_status() {
					ChannelUpdateStatus::Enabled if !chan.is_live() => chan.set_channel_update_status(ChannelUpdateStatus::DisabledStaged),
					ChannelUpdateStatus::Disabled if chan.is_live() => chan.set_channel_update_status(ChannelUpdateStatus::EnabledStaged),
					ChannelUpdateStatus::DisabledStaged if chan.is_live() => chan.set_channel_update_status(ChannelUpdateStatus::Enabled),
					ChannelUpdateStatus::EnabledStaged if !chan.is_live() => chan.set_channel_update_status(ChannelUpdateStatus::Disabled),
					ChannelUpdateStatus::DisabledStaged if !chan.is_live() => {
						if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
							channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
								msg: update
							});
						}
						should_persist = NotifyOption::DoPersist;
						chan.set_channel_update_status(ChannelUpdateStatus::Disabled);
					},
					ChannelUpdateStatus::EnabledStaged if chan.is_live() => {
						if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
							channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
								msg: update
							});
						}
						should_persist = NotifyOption::DoPersist;
						chan.set_channel_update_status(ChannelUpdateStatus::Enabled);
					},
					_ => {},
				}
			}

			should_persist
		});
	}

	/// Indicates that the preimage for payment_hash is unknown or the received amount is incorrect
	/// after a PaymentReceived event, failing the HTLC back to its origin and freeing resources
	/// along the path (including in our own channel on which we received it).
	/// Returns false if no payment was found to fail backwards, true if the process of failing the
	/// HTLC backwards has been started.
	pub fn fail_htlc_backwards(&self, payment_hash: &PaymentHash) -> bool {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		let mut channel_state = Some(self.channel_state.lock().unwrap());
		let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(payment_hash);
		if let Some(mut sources) = removed_source {
			for htlc in sources.drain(..) {
				if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); }
				let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
				htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(
						self.best_block.read().unwrap().height()));
				self.fail_htlc_backwards_internal(channel_state.take().unwrap(),
						HTLCSource::PreviousHopData(htlc.prev_hop), payment_hash,
						HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: htlc_msat_height_data });
			}
			true
		} else { false }
	}

	// Fail a list of HTLCs that were just freed from the holding cell. The HTLCs need to be
	// failed backwards or, if they were one of our outgoing HTLCs, then their failure needs to
	// be surfaced to the user.
	fn fail_holding_cell_htlcs(&self, mut htlcs_to_fail: Vec<(HTLCSource, PaymentHash)>, channel_id: [u8; 32]) {
		for (htlc_src, payment_hash) in htlcs_to_fail.drain(..) {
			match htlc_src {
				HTLCSource::PreviousHopData(HTLCPreviousHopData { .. }) => {
					let (failure_code, onion_failure_data) =
						match self.channel_state.lock().unwrap().by_id.entry(channel_id) {
							hash_map::Entry::Occupied(chan_entry) => {
								if let Ok(upd) = self.get_channel_update_for_unicast(&chan_entry.get()) {
									(0x1000|7, upd.encode_with_len())
								} else {
									(0x4000|10, Vec::new())
								}
							},
							hash_map::Entry::Vacant(_) => (0x4000|10, Vec::new())
						};
					let channel_state = self.channel_state.lock().unwrap();
					self.fail_htlc_backwards_internal(channel_state,
						htlc_src, &payment_hash, HTLCFailReason::Reason { failure_code, data: onion_failure_data});
				},
				HTLCSource::OutboundRoute { session_priv, .. } => {
					if {
						let mut session_priv_bytes = [0; 32];
						session_priv_bytes.copy_from_slice(&session_priv[..]);
						self.pending_outbound_payments.lock().unwrap().remove(&session_priv_bytes)
					} {
						self.pending_events.lock().unwrap().push(
							events::Event::PaymentFailed {
								payment_hash,
								rejected_by_dest: false,
#[cfg(test)]
								error_code: None,
#[cfg(test)]
								error_data: None,
							}
						)
					} else {
						log_trace!(self.logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
					}
				},
			};
		}
	}

	/// Fails an HTLC backwards to the sender of it to us.
	/// Note that while we take a channel_state lock as input, we do *not* assume consistency here.
	/// There are several callsites that do stupid things like loop over a list of payment_hashes
	/// to fail and take the channel_state lock for each iteration (as we take ownership and may
	/// drop it). In other words, no assumptions are made that entries in claimable_htlcs point to
	/// still-available channels.
	fn fail_htlc_backwards_internal(&self, mut channel_state_lock: MutexGuard<ChannelHolder<Signer>>, source: HTLCSource, payment_hash: &PaymentHash, onion_error: HTLCFailReason) {
		//TODO: There is a timing attack here where if a node fails an HTLC back to us they can
		//identify whether we sent it or not based on the (I presume) very different runtime
		//between the branches here. We should make this async and move it into the forward HTLCs
		//timer handling.

		// Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
		// from block_connected which may run during initialization prior to the chain_monitor
		// being fully configured. See the docs for `ChannelManagerReadArgs` for more.
		match source {
			HTLCSource::OutboundRoute { ref path, session_priv, .. } => {
				if {
					let mut session_priv_bytes = [0; 32];
					session_priv_bytes.copy_from_slice(&session_priv[..]);
					!self.pending_outbound_payments.lock().unwrap().remove(&session_priv_bytes)
				} {
					log_trace!(self.logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
					return;
				}
				log_trace!(self.logger, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
				mem::drop(channel_state_lock);
				match &onion_error {
					&HTLCFailReason::LightningError { ref err } => {
#[cfg(test)]
						let (channel_update, payment_retryable, onion_error_code, onion_error_data) = onion_utils::process_onion_failure(&self.secp_ctx, &self.logger, &source, err.data.clone());
#[cfg(not(test))]
						let (channel_update, payment_retryable, _, _) = onion_utils::process_onion_failure(&self.secp_ctx, &self.logger, &source, err.data.clone());
						// TODO: If we decided to blame ourselves (or one of our channels) in
						// process_onion_failure we should close that channel as it implies our
						// next-hop is needlessly blaming us!
						if let Some(update) = channel_update {
							self.channel_state.lock().unwrap().pending_msg_events.push(
								events::MessageSendEvent::PaymentFailureNetworkUpdate {
									update,
								}
							);
						}
						self.pending_events.lock().unwrap().push(
							events::Event::PaymentFailed {
								payment_hash: payment_hash.clone(),
								rejected_by_dest: !payment_retryable,
#[cfg(test)]
								error_code: onion_error_code,
#[cfg(test)]
								error_data: onion_error_data
							}
						);
					},
					&HTLCFailReason::Reason {
#[cfg(test)]
							ref failure_code,
#[cfg(test)]
							ref data,
							.. } => {
						// we get a fail_malformed_htlc from the first hop
						// TODO: We'd like to generate a PaymentFailureNetworkUpdate for temporary
						// failures here, but that would be insufficient as get_route
						// generally ignores its view of our own channels as we provide them via
						// ChannelDetails.
						// TODO: For non-temporary failures, we really should be closing the
						// channel here as we apparently can't relay through them anyway.
						self.pending_events.lock().unwrap().push(
							events::Event::PaymentFailed {
								payment_hash: payment_hash.clone(),
								rejected_by_dest: path.len() == 1,
#[cfg(test)]
								error_code: Some(*failure_code),
#[cfg(test)]
								error_data: Some(data.clone()),
							}
						);
					}
				}
			},
			HTLCSource::PreviousHopData(HTLCPreviousHopData { short_channel_id, htlc_id, incoming_packet_shared_secret, .. }) => {
				let err_packet = match onion_error {
					HTLCFailReason::Reason { failure_code, data } => {
						log_trace!(self.logger, "Failing HTLC with payment_hash {} backwards from us with code {}", log_bytes!(payment_hash.0), failure_code);
						let packet = onion_utils::build_failure_packet(&incoming_packet_shared_secret, failure_code, &data[..]).encode();
						onion_utils::encrypt_failure_packet(&incoming_packet_shared_secret, &packet)
					},
					HTLCFailReason::LightningError { err } => {
						log_trace!(self.logger, "Failing HTLC with payment_hash {} backwards with pre-built LightningError", log_bytes!(payment_hash.0));
						onion_utils::encrypt_failure_packet(&incoming_packet_shared_secret, &err.data)
					}
				};

				let mut forward_event = None;
				if channel_state_lock.forward_htlcs.is_empty() {
					forward_event = Some(Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS));
				}
				match channel_state_lock.forward_htlcs.entry(short_channel_id) {
					hash_map::Entry::Occupied(mut entry) => {
						entry.get_mut().push(HTLCForwardInfo::FailHTLC { htlc_id, err_packet });
					},
					hash_map::Entry::Vacant(entry) => {
						entry.insert(vec!(HTLCForwardInfo::FailHTLC { htlc_id, err_packet }));
					}
				}
				mem::drop(channel_state_lock);
				if let Some(time) = forward_event {
					let mut pending_events = self.pending_events.lock().unwrap();
					pending_events.push(events::Event::PendingHTLCsForwardable {
						time_forwardable: time
					});
				}
			},
		}
	}

	/// Provides a payment preimage in response to a PaymentReceived event, returning true and
	/// generating message events for the net layer to claim the payment, if possible. Thus, you
	/// should probably kick the net layer to go send messages if this returns true!
	///
	/// Note that if you did not set an `amount_msat` when calling [`create_inbound_payment`] or
	/// [`create_inbound_payment_for_hash`] you must check that the amount in the `PaymentReceived`
	/// event matches your expectation. If you fail to do so and call this method, you may provide
	/// the sender "proof-of-payment" when they did not fulfill the full expected payment.
	///
	/// May panic if called except in response to a PaymentReceived event.
	///
	/// [`create_inbound_payment`]: Self::create_inbound_payment
	/// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash
	pub fn claim_funds(&self, payment_preimage: PaymentPreimage) -> bool {
		let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());

		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		let mut channel_state = Some(self.channel_state.lock().unwrap());
		let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(&payment_hash);
		if let Some(mut sources) = removed_source {
			assert!(!sources.is_empty());

			// If we are claiming an MPP payment, we have to take special care to ensure that each
			// channel exists before claiming all of the payments (inside one lock).
			// Note that channel existance is sufficient as we should always get a monitor update
			// which will take care of the real HTLC claim enforcement.
			//
			// If we find an HTLC which we would need to claim but for which we do not have a
			// channel, we will fail all parts of the MPP payment. While we could wait and see if
			// the sender retries the already-failed path(s), it should be a pretty rare case where
			// we got all the HTLCs and then a channel closed while we were waiting for the user to
			// provide the preimage, so worrying too much about the optimal handling isn't worth
			// it.
			let mut valid_mpp = true;
			for htlc in sources.iter() {
				if let None = channel_state.as_ref().unwrap().short_to_id.get(&htlc.prev_hop.short_channel_id) {
					valid_mpp = false;
					break;
				}
			}

			let mut errs = Vec::new();
			let mut claimed_any_htlcs = false;
			for htlc in sources.drain(..) {
				if !valid_mpp {
					if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); }
					let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
					htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(
							self.best_block.read().unwrap().height()));
					self.fail_htlc_backwards_internal(channel_state.take().unwrap(),
									 HTLCSource::PreviousHopData(htlc.prev_hop), &payment_hash,
									 HTLCFailReason::Reason { failure_code: 0x4000|15, data: htlc_msat_height_data });
				} else {
					match self.claim_funds_from_hop(channel_state.as_mut().unwrap(), htlc.prev_hop, payment_preimage) {
						Err(Some(e)) => {
							if let msgs::ErrorAction::IgnoreError = e.1.err.action {
								// We got a temporary failure updating monitor, but will claim the
								// HTLC when the monitor updating is restored (or on chain).
								log_error!(self.logger, "Temporary failure claiming HTLC, treating as success: {}", e.1.err.err);
								claimed_any_htlcs = true;
							} else { errs.push(e); }
						},
						Err(None) => unreachable!("We already checked for channel existence, we can't fail here!"),
						Ok(()) => claimed_any_htlcs = true,
					}
				}
			}

			// Now that we've done the entire above loop in one lock, we can handle any errors
			// which were generated.
			channel_state.take();

			for (counterparty_node_id, err) in errs.drain(..) {
				let res: Result<(), _> = Err(err);
				let _ = handle_error!(self, res, counterparty_node_id);
			}

			claimed_any_htlcs
		} else { false }
	}

	fn claim_funds_from_hop(&self, channel_state_lock: &mut MutexGuard<ChannelHolder<Signer>>, prev_hop: HTLCPreviousHopData, payment_preimage: PaymentPreimage) -> Result<(), Option<(PublicKey, MsgHandleErrInternal)>> {
		//TODO: Delay the claimed_funds relaying just like we do outbound relay!
		let channel_state = &mut **channel_state_lock;
		let chan_id = match channel_state.short_to_id.get(&prev_hop.short_channel_id) {
			Some(chan_id) => chan_id.clone(),
			None => {
				return Err(None)
			}
		};

		if let hash_map::Entry::Occupied(mut chan) = channel_state.by_id.entry(chan_id) {
			let was_frozen_for_monitor = chan.get().is_awaiting_monitor_update();
			match chan.get_mut().get_update_fulfill_htlc_and_commit(prev_hop.htlc_id, payment_preimage, &self.logger) {
				Ok((msgs, monitor_option)) => {
					if let Some(monitor_update) = monitor_option {
						if let Err(e) = self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), monitor_update) {
							if was_frozen_for_monitor {
								assert!(msgs.is_none());
							} else {
								return Err(Some((chan.get().get_counterparty_node_id(), handle_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::CommitmentFirst, false, msgs.is_some()).unwrap_err())));
							}
						}
					}
					if let Some((msg, commitment_signed)) = msgs {
						log_debug!(self.logger, "Claiming funds for HTLC with preimage {} resulted in a commitment_signed for channel {}",
							log_bytes!(payment_preimage.0), log_bytes!(chan.get().channel_id()));
						channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
							node_id: chan.get().get_counterparty_node_id(),
							updates: msgs::CommitmentUpdate {
								update_add_htlcs: Vec::new(),
								update_fulfill_htlcs: vec![msg],
								update_fail_htlcs: Vec::new(),
								update_fail_malformed_htlcs: Vec::new(),
								update_fee: None,
								commitment_signed,
							}
						});
					}
					return Ok(())
				},
				Err(e) => {
					// TODO: Do something with e?
					// This should only occur if we are claiming an HTLC at the same time as the
					// HTLC is being failed (eg because a block is being connected and this caused
					// an HTLC to time out). This should, of course, only occur if the user is the
					// one doing the claiming (as it being a part of a peer claim would imply we're
					// about to lose funds) and only if the lock in claim_funds was dropped as a
					// previous HTLC was failed (thus not for an MPP payment).
					debug_assert!(false, "This shouldn't be reachable except in absurdly rare cases between monitor updates and HTLC timeouts: {:?}", e);
					return Err(None)
				},
			}
		} else { unreachable!(); }
	}

	fn claim_funds_internal(&self, mut channel_state_lock: MutexGuard<ChannelHolder<Signer>>, source: HTLCSource, payment_preimage: PaymentPreimage) {
		match source {
			HTLCSource::OutboundRoute { session_priv, .. } => {
				mem::drop(channel_state_lock);
				if {
					let mut session_priv_bytes = [0; 32];
					session_priv_bytes.copy_from_slice(&session_priv[..]);
					self.pending_outbound_payments.lock().unwrap().remove(&session_priv_bytes)
				} {
					let mut pending_events = self.pending_events.lock().unwrap();
					pending_events.push(events::Event::PaymentSent {
						payment_preimage
					});
				} else {
					log_trace!(self.logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
				}
			},
			HTLCSource::PreviousHopData(hop_data) => {
				let prev_outpoint = hop_data.outpoint;
				if let Err((counterparty_node_id, err)) = match self.claim_funds_from_hop(&mut channel_state_lock, hop_data, payment_preimage) {
					Ok(()) => Ok(()),
					Err(None) => {
						let preimage_update = ChannelMonitorUpdate {
							update_id: CLOSED_CHANNEL_UPDATE_ID,
							updates: vec![ChannelMonitorUpdateStep::PaymentPreimage {
								payment_preimage: payment_preimage.clone(),
							}],
						};
						// We update the ChannelMonitor on the backward link, after
						// receiving an offchain preimage event from the forward link (the
						// event being update_fulfill_htlc).
						if let Err(e) = self.chain_monitor.update_channel(prev_outpoint, preimage_update) {
							log_error!(self.logger, "Critical error: failed to update channel monitor with preimage {:?}: {:?}",
							           payment_preimage, e);
						}
						Ok(())
					},
					Err(Some(res)) => Err(res),
				} {
					mem::drop(channel_state_lock);
					let res: Result<(), _> = Err(err);
					let _ = handle_error!(self, res, counterparty_node_id);
				}
			},
		}
	}

	/// Gets the node_id held by this ChannelManager
	pub fn get_our_node_id(&self) -> PublicKey {
		self.our_network_pubkey.clone()
	}

	/// Restores a single, given channel to normal operation after a
	/// ChannelMonitorUpdateErr::TemporaryFailure was returned from a channel monitor update
	/// operation.
	///
	/// All ChannelMonitor updates up to and including highest_applied_update_id must have been
	/// fully committed in every copy of the given channels' ChannelMonitors.
	///
	/// Note that there is no effect to calling with a highest_applied_update_id other than the
	/// current latest ChannelMonitorUpdate and one call to this function after multiple
	/// ChannelMonitorUpdateErr::TemporaryFailures is fine. The highest_applied_update_id field
	/// exists largely only to prevent races between this and concurrent update_monitor calls.
	///
	/// Thus, the anticipated use is, at a high level:
	///  1) You register a chain::Watch with this ChannelManager,
	///  2) it stores each update to disk, and begins updating any remote (eg watchtower) copies of
	///     said ChannelMonitors as it can, returning ChannelMonitorUpdateErr::TemporaryFailures
	///     any time it cannot do so instantly,
	///  3) update(s) are applied to each remote copy of a ChannelMonitor,
	///  4) once all remote copies are updated, you call this function with the update_id that
	///     completed, and once it is the latest the Channel will be re-enabled.
	pub fn channel_monitor_updated(&self, funding_txo: &OutPoint, highest_applied_update_id: u64) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		let chan_restoration_res;
		let mut pending_failures = {
			let mut channel_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_lock;
			let mut channel = match channel_state.by_id.entry(funding_txo.to_channel_id()) {
				hash_map::Entry::Occupied(chan) => chan,
				hash_map::Entry::Vacant(_) => return,
			};
			if !channel.get().is_awaiting_monitor_update() || channel.get().get_latest_monitor_update_id() != highest_applied_update_id {
				return;
			}

			let (raa, commitment_update, order, pending_forwards, pending_failures, funding_broadcastable, funding_locked) = channel.get_mut().monitor_updating_restored(&self.logger);
			let channel_update = if funding_locked.is_some() && channel.get().is_usable() && !channel.get().should_announce() {
				// We only send a channel_update in the case where we are just now sending a
				// funding_locked and the channel is in a usable state. Further, we rely on the
				// normal announcement_signatures process to send a channel_update for public
				// channels, only generating a unicast channel_update if this is a private channel.
				Some(events::MessageSendEvent::SendChannelUpdate {
					node_id: channel.get().get_counterparty_node_id(),
					msg: self.get_channel_update_for_unicast(channel.get()).unwrap(),
				})
			} else { None };
			chan_restoration_res = handle_chan_restoration_locked!(self, channel_lock, channel_state, channel, raa, commitment_update, order, None, pending_forwards, funding_broadcastable, funding_locked);
			if let Some(upd) = channel_update {
				channel_state.pending_msg_events.push(upd);
			}
			pending_failures
		};
		post_handle_chan_restoration!(self, chan_restoration_res);
		for failure in pending_failures.drain(..) {
			self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), failure.0, &failure.1, failure.2);
		}
	}

	fn internal_open_channel(&self, counterparty_node_id: &PublicKey, their_features: InitFeatures, msg: &msgs::OpenChannel) -> Result<(), MsgHandleErrInternal> {
		if msg.chain_hash != self.genesis_hash {
			return Err(MsgHandleErrInternal::send_err_msg_no_close("Unknown genesis block hash".to_owned(), msg.temporary_channel_id.clone()));
		}

		let channel = Channel::new_from_req(&self.fee_estimator, &self.keys_manager, counterparty_node_id.clone(), their_features, msg, 0, &self.default_configuration)
			.map_err(|e| MsgHandleErrInternal::from_chan_no_close(e, msg.temporary_channel_id))?;
		let mut channel_state_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_state_lock;
		match channel_state.by_id.entry(channel.channel_id()) {
			hash_map::Entry::Occupied(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("temporary_channel_id collision!".to_owned(), msg.temporary_channel_id.clone())),
			hash_map::Entry::Vacant(entry) => {
				channel_state.pending_msg_events.push(events::MessageSendEvent::SendAcceptChannel {
					node_id: counterparty_node_id.clone(),
					msg: channel.get_accept_channel(),
				});
				entry.insert(channel);
			}
		}
		Ok(())
	}

	fn internal_accept_channel(&self, counterparty_node_id: &PublicKey, their_features: InitFeatures, msg: &msgs::AcceptChannel) -> Result<(), MsgHandleErrInternal> {
		let (value, output_script, user_id) = {
			let mut channel_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_lock;
			match channel_state.by_id.entry(msg.temporary_channel_id) {
				hash_map::Entry::Occupied(mut chan) => {
					if chan.get().get_counterparty_node_id() != *counterparty_node_id {
						return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.temporary_channel_id));
					}
					try_chan_entry!(self, chan.get_mut().accept_channel(&msg, &self.default_configuration, their_features), channel_state, chan);
					(chan.get().get_value_satoshis(), chan.get().get_funding_redeemscript().to_v0_p2wsh(), chan.get().get_user_id())
				},
				hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.temporary_channel_id))
			}
		};
		let mut pending_events = self.pending_events.lock().unwrap();
		pending_events.push(events::Event::FundingGenerationReady {
			temporary_channel_id: msg.temporary_channel_id,
			channel_value_satoshis: value,
			output_script,
			user_channel_id: user_id,
		});
		Ok(())
	}

	fn internal_funding_created(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingCreated) -> Result<(), MsgHandleErrInternal> {
		let ((funding_msg, monitor), mut chan) = {
			let best_block = *self.best_block.read().unwrap();
			let mut channel_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_lock;
			match channel_state.by_id.entry(msg.temporary_channel_id.clone()) {
				hash_map::Entry::Occupied(mut chan) => {
					if chan.get().get_counterparty_node_id() != *counterparty_node_id {
						return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.temporary_channel_id));
					}
					(try_chan_entry!(self, chan.get_mut().funding_created(msg, best_block, &self.logger), channel_state, chan), chan.remove())
				},
				hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.temporary_channel_id))
			}
		};
		// Because we have exclusive ownership of the channel here we can release the channel_state
		// lock before watch_channel
		if let Err(e) = self.chain_monitor.watch_channel(monitor.get_funding_txo().0, monitor) {
			match e {
				ChannelMonitorUpdateErr::PermanentFailure => {
					// Note that we reply with the new channel_id in error messages if we gave up on the
					// channel, not the temporary_channel_id. This is compatible with ourselves, but the
					// spec is somewhat ambiguous here. Not a huge deal since we'll send error messages for
					// any messages referencing a previously-closed channel anyway.
					// We do not do a force-close here as that would generate a monitor update for
					// a monitor that we didn't manage to store (and that we don't care about - we
					// don't respond with the funding_signed so the channel can never go on chain).
					let (_monitor_update, failed_htlcs) = chan.force_shutdown(true);
					assert!(failed_htlcs.is_empty());
					return Err(MsgHandleErrInternal::send_err_msg_no_close("ChannelMonitor storage failure".to_owned(), funding_msg.channel_id));
				},
				ChannelMonitorUpdateErr::TemporaryFailure => {
					// There's no problem signing a counterparty's funding transaction if our monitor
					// hasn't persisted to disk yet - we can't lose money on a transaction that we haven't
					// accepted payment from yet. We do, however, need to wait to send our funding_locked
					// until we have persisted our monitor.
					chan.monitor_update_failed(false, false, Vec::new(), Vec::new());
				},
			}
		}
		let mut channel_state_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_state_lock;
		match channel_state.by_id.entry(funding_msg.channel_id) {
			hash_map::Entry::Occupied(_) => {
				return Err(MsgHandleErrInternal::send_err_msg_no_close("Already had channel with the new channel_id".to_owned(), funding_msg.channel_id))
			},
			hash_map::Entry::Vacant(e) => {
				channel_state.pending_msg_events.push(events::MessageSendEvent::SendFundingSigned {
					node_id: counterparty_node_id.clone(),
					msg: funding_msg,
				});
				e.insert(chan);
			}
		}
		Ok(())
	}

	fn internal_funding_signed(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingSigned) -> Result<(), MsgHandleErrInternal> {
		let funding_tx = {
			let best_block = *self.best_block.read().unwrap();
			let mut channel_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_lock;
			match channel_state.by_id.entry(msg.channel_id) {
				hash_map::Entry::Occupied(mut chan) => {
					if chan.get().get_counterparty_node_id() != *counterparty_node_id {
						return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
					}
					let (monitor, funding_tx) = match chan.get_mut().funding_signed(&msg, best_block, &self.logger) {
						Ok(update) => update,
						Err(e) => try_chan_entry!(self, Err(e), channel_state, chan),
					};
					if let Err(e) = self.chain_monitor.watch_channel(chan.get().get_funding_txo().unwrap(), monitor) {
						return_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::RevokeAndACKFirst, false, false);
					}
					funding_tx
				},
				hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
			}
		};
		log_info!(self.logger, "Broadcasting funding transaction with txid {}", funding_tx.txid());
		self.tx_broadcaster.broadcast_transaction(&funding_tx);
		Ok(())
	}

	fn internal_funding_locked(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingLocked) -> Result<(), MsgHandleErrInternal> {
		let mut channel_state_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_state_lock;
		match channel_state.by_id.entry(msg.channel_id) {
			hash_map::Entry::Occupied(mut chan) => {
				if chan.get().get_counterparty_node_id() != *counterparty_node_id {
					return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
				}
				try_chan_entry!(self, chan.get_mut().funding_locked(&msg, &self.logger), channel_state, chan);
				if let Some(announcement_sigs) = self.get_announcement_sigs(chan.get()) {
					log_trace!(self.logger, "Sending announcement_signatures for {} in response to funding_locked", log_bytes!(chan.get().channel_id()));
					// If we see locking block before receiving remote funding_locked, we broadcast our
					// announcement_sigs at remote funding_locked reception. If we receive remote
					// funding_locked before seeing locking block, we broadcast our announcement_sigs at locking
					// block connection. We should guanrantee to broadcast announcement_sigs to our peer whatever
					// the order of the events but our peer may not receive it due to disconnection. The specs
					// lacking an acknowledgement for announcement_sigs we may have to re-send them at peer
					// connection in the future if simultaneous misses by both peers due to network/hardware
					// failures is an issue. Note, to achieve its goal, only one of the announcement_sigs needs
					// to be received, from then sigs are going to be flood to the whole network.
					channel_state.pending_msg_events.push(events::MessageSendEvent::SendAnnouncementSignatures {
						node_id: counterparty_node_id.clone(),
						msg: announcement_sigs,
					});
				} else if chan.get().is_usable() {
					channel_state.pending_msg_events.push(events::MessageSendEvent::SendChannelUpdate {
						node_id: counterparty_node_id.clone(),
						msg: self.get_channel_update_for_unicast(chan.get()).unwrap(),
					});
				}
				Ok(())
			},
			hash_map::Entry::Vacant(_) => Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
		}
	}

	fn internal_shutdown(&self, counterparty_node_id: &PublicKey, their_features: &InitFeatures, msg: &msgs::Shutdown) -> Result<(), MsgHandleErrInternal> {
		let (mut dropped_htlcs, chan_option) = {
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;

			match channel_state.by_id.entry(msg.channel_id.clone()) {
				hash_map::Entry::Occupied(mut chan_entry) => {
					if chan_entry.get().get_counterparty_node_id() != *counterparty_node_id {
						return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
					}
					let (shutdown, closing_signed, dropped_htlcs) = try_chan_entry!(self, chan_entry.get_mut().shutdown(&self.fee_estimator, &their_features, &msg), channel_state, chan_entry);
					if let Some(msg) = shutdown {
						channel_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
							node_id: counterparty_node_id.clone(),
							msg,
						});
					}
					if let Some(msg) = closing_signed {
						channel_state.pending_msg_events.push(events::MessageSendEvent::SendClosingSigned {
							node_id: counterparty_node_id.clone(),
							msg,
						});
					}
					if chan_entry.get().is_shutdown() {
						if let Some(short_id) = chan_entry.get().get_short_channel_id() {
							channel_state.short_to_id.remove(&short_id);
						}
						(dropped_htlcs, Some(chan_entry.remove_entry().1))
					} else { (dropped_htlcs, None) }
				},
				hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
			}
		};
		for htlc_source in dropped_htlcs.drain(..) {
			self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() });
		}
		if let Some(chan) = chan_option {
			if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
				let mut channel_state = self.channel_state.lock().unwrap();
				channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
					msg: update
				});
			}
		}
		Ok(())
	}

	fn internal_closing_signed(&self, counterparty_node_id: &PublicKey, msg: &msgs::ClosingSigned) -> Result<(), MsgHandleErrInternal> {
		let (tx, chan_option) = {
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;
			match channel_state.by_id.entry(msg.channel_id.clone()) {
				hash_map::Entry::Occupied(mut chan_entry) => {
					if chan_entry.get().get_counterparty_node_id() != *counterparty_node_id {
						return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
					}
					let (closing_signed, tx) = try_chan_entry!(self, chan_entry.get_mut().closing_signed(&self.fee_estimator, &msg), channel_state, chan_entry);
					if let Some(msg) = closing_signed {
						channel_state.pending_msg_events.push(events::MessageSendEvent::SendClosingSigned {
							node_id: counterparty_node_id.clone(),
							msg,
						});
					}
					if tx.is_some() {
						// We're done with this channel, we've got a signed closing transaction and
						// will send the closing_signed back to the remote peer upon return. This
						// also implies there are no pending HTLCs left on the channel, so we can
						// fully delete it from tracking (the channel monitor is still around to
						// watch for old state broadcasts)!
						if let Some(short_id) = chan_entry.get().get_short_channel_id() {
							channel_state.short_to_id.remove(&short_id);
						}
						(tx, Some(chan_entry.remove_entry().1))
					} else { (tx, None) }
				},
				hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
			}
		};
		if let Some(broadcast_tx) = tx {
			log_info!(self.logger, "Broadcasting {}", log_tx!(broadcast_tx));
			self.tx_broadcaster.broadcast_transaction(&broadcast_tx);
		}
		if let Some(chan) = chan_option {
			if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
				let mut channel_state = self.channel_state.lock().unwrap();
				channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
					msg: update
				});
			}
		}
		Ok(())
	}

	fn internal_update_add_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateAddHTLC) -> Result<(), MsgHandleErrInternal> {
		//TODO: BOLT 4 points out a specific attack where a peer may re-send an onion packet and
		//determine the state of the payment based on our response/if we forward anything/the time
		//we take to respond. We should take care to avoid allowing such an attack.
		//
		//TODO: There exists a further attack where a node may garble the onion data, forward it to
		//us repeatedly garbled in different ways, and compare our error messages, which are
		//encrypted with the same key. It's not immediately obvious how to usefully exploit that,
		//but we should prevent it anyway.

		let (pending_forward_info, mut channel_state_lock) = self.decode_update_add_htlc_onion(msg);
		let channel_state = &mut *channel_state_lock;

		match channel_state.by_id.entry(msg.channel_id) {
			hash_map::Entry::Occupied(mut chan) => {
				if chan.get().get_counterparty_node_id() != *counterparty_node_id {
					return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
				}

				let create_pending_htlc_status = |chan: &Channel<Signer>, pending_forward_info: PendingHTLCStatus, error_code: u16| {
					// Ensure error_code has the UPDATE flag set, since by default we send a
					// channel update along as part of failing the HTLC.
					assert!((error_code & 0x1000) != 0);
					// If the update_add is completely bogus, the call will Err and we will close,
					// but if we've sent a shutdown and they haven't acknowledged it yet, we just
					// want to reject the new HTLC and fail it backwards instead of forwarding.
					match pending_forward_info {
						PendingHTLCStatus::Forward(PendingHTLCInfo { ref incoming_shared_secret, .. }) => {
							let reason = if let Ok(upd) = self.get_channel_update_for_unicast(chan) {
								onion_utils::build_first_hop_failure_packet(incoming_shared_secret, error_code, &{
									let mut res = Vec::with_capacity(8 + 128);
									// TODO: underspecified, follow https://github.com/lightningnetwork/lightning-rfc/issues/791
									res.extend_from_slice(&byte_utils::be16_to_array(0));
									res.extend_from_slice(&upd.encode_with_len()[..]);
									res
								}[..])
							} else {
								// The only case where we'd be unable to
								// successfully get a channel update is if the
								// channel isn't in the fully-funded state yet,
								// implying our counterparty is trying to route
								// payments over the channel back to themselves
								// (cause no one else should know the short_id
								// is a lightning channel yet). We should have
								// no problem just calling this
								// unknown_next_peer (0x4000|10).
								onion_utils::build_first_hop_failure_packet(incoming_shared_secret, 0x4000|10, &[])
							};
							let msg = msgs::UpdateFailHTLC {
								channel_id: msg.channel_id,
								htlc_id: msg.htlc_id,
								reason
							};
							PendingHTLCStatus::Fail(HTLCFailureMsg::Relay(msg))
						},
						_ => pending_forward_info
					}
				};
				try_chan_entry!(self, chan.get_mut().update_add_htlc(&msg, pending_forward_info, create_pending_htlc_status, &self.logger), channel_state, chan);
			},
			hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
		}
		Ok(())
	}

	fn internal_update_fulfill_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFulfillHTLC) -> Result<(), MsgHandleErrInternal> {
		let mut channel_lock = self.channel_state.lock().unwrap();
		let htlc_source = {
			let channel_state = &mut *channel_lock;
			match channel_state.by_id.entry(msg.channel_id) {
				hash_map::Entry::Occupied(mut chan) => {
					if chan.get().get_counterparty_node_id() != *counterparty_node_id {
						return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
					}
					try_chan_entry!(self, chan.get_mut().update_fulfill_htlc(&msg), channel_state, chan)
				},
				hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
			}
		};
		self.claim_funds_internal(channel_lock, htlc_source, msg.payment_preimage.clone());
		Ok(())
	}

	fn internal_update_fail_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFailHTLC) -> Result<(), MsgHandleErrInternal> {
		let mut channel_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_lock;
		match channel_state.by_id.entry(msg.channel_id) {
			hash_map::Entry::Occupied(mut chan) => {
				if chan.get().get_counterparty_node_id() != *counterparty_node_id {
					return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
				}
				try_chan_entry!(self, chan.get_mut().update_fail_htlc(&msg, HTLCFailReason::LightningError { err: msg.reason.clone() }), channel_state, chan);
			},
			hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
		}
		Ok(())
	}

	fn internal_update_fail_malformed_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFailMalformedHTLC) -> Result<(), MsgHandleErrInternal> {
		let mut channel_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_lock;
		match channel_state.by_id.entry(msg.channel_id) {
			hash_map::Entry::Occupied(mut chan) => {
				if chan.get().get_counterparty_node_id() != *counterparty_node_id {
					return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
				}
				if (msg.failure_code & 0x8000) == 0 {
					let chan_err: ChannelError = ChannelError::Close("Got update_fail_malformed_htlc with BADONION not set".to_owned());
					try_chan_entry!(self, Err(chan_err), channel_state, chan);
				}
				try_chan_entry!(self, chan.get_mut().update_fail_malformed_htlc(&msg, HTLCFailReason::Reason { failure_code: msg.failure_code, data: Vec::new() }), channel_state, chan);
				Ok(())
			},
			hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
		}
	}

	fn internal_commitment_signed(&self, counterparty_node_id: &PublicKey, msg: &msgs::CommitmentSigned) -> Result<(), MsgHandleErrInternal> {
		let mut channel_state_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_state_lock;
		match channel_state.by_id.entry(msg.channel_id) {
			hash_map::Entry::Occupied(mut chan) => {
				if chan.get().get_counterparty_node_id() != *counterparty_node_id {
					return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
				}
				let (revoke_and_ack, commitment_signed, closing_signed, monitor_update) =
					match chan.get_mut().commitment_signed(&msg, &self.fee_estimator, &self.logger) {
						Err((None, e)) => try_chan_entry!(self, Err(e), channel_state, chan),
						Err((Some(update), e)) => {
							assert!(chan.get().is_awaiting_monitor_update());
							let _ = self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), update);
							try_chan_entry!(self, Err(e), channel_state, chan);
							unreachable!();
						},
						Ok(res) => res
					};
				if let Err(e) = self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), monitor_update) {
					return_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::RevokeAndACKFirst, true, commitment_signed.is_some());
					//TODO: Rebroadcast closing_signed if present on monitor update restoration
				}
				channel_state.pending_msg_events.push(events::MessageSendEvent::SendRevokeAndACK {
					node_id: counterparty_node_id.clone(),
					msg: revoke_and_ack,
				});
				if let Some(msg) = commitment_signed {
					channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
						node_id: counterparty_node_id.clone(),
						updates: msgs::CommitmentUpdate {
							update_add_htlcs: Vec::new(),
							update_fulfill_htlcs: Vec::new(),
							update_fail_htlcs: Vec::new(),
							update_fail_malformed_htlcs: Vec::new(),
							update_fee: None,
							commitment_signed: msg,
						},
					});
				}
				if let Some(msg) = closing_signed {
					channel_state.pending_msg_events.push(events::MessageSendEvent::SendClosingSigned {
						node_id: counterparty_node_id.clone(),
						msg,
					});
				}
				Ok(())
			},
			hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
		}
	}

	#[inline]
	fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, OutPoint, Vec<(PendingHTLCInfo, u64)>)]) {
		for &mut (prev_short_channel_id, prev_funding_outpoint, ref mut pending_forwards) in per_source_pending_forwards {
			let mut forward_event = None;
			if !pending_forwards.is_empty() {
				let mut channel_state = self.channel_state.lock().unwrap();
				if channel_state.forward_htlcs.is_empty() {
					forward_event = Some(Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS))
				}
				for (forward_info, prev_htlc_id) in pending_forwards.drain(..) {
					match channel_state.forward_htlcs.entry(match forward_info.routing {
							PendingHTLCRouting::Forward { short_channel_id, .. } => short_channel_id,
							PendingHTLCRouting::Receive { .. } => 0,
					}) {
						hash_map::Entry::Occupied(mut entry) => {
							entry.get_mut().push(HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_funding_outpoint,
							                                                prev_htlc_id, forward_info });
						},
						hash_map::Entry::Vacant(entry) => {
							entry.insert(vec!(HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_funding_outpoint,
							                                             prev_htlc_id, forward_info }));
						}
					}
				}
			}
			match forward_event {
				Some(time) => {
					let mut pending_events = self.pending_events.lock().unwrap();
					pending_events.push(events::Event::PendingHTLCsForwardable {
						time_forwardable: time
					});
				}
				None => {},
			}
		}
	}

	fn internal_revoke_and_ack(&self, counterparty_node_id: &PublicKey, msg: &msgs::RevokeAndACK) -> Result<(), MsgHandleErrInternal> {
		let mut htlcs_to_fail = Vec::new();
		let res = loop {
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;
			match channel_state.by_id.entry(msg.channel_id) {
				hash_map::Entry::Occupied(mut chan) => {
					if chan.get().get_counterparty_node_id() != *counterparty_node_id {
						break Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
					}
					let was_frozen_for_monitor = chan.get().is_awaiting_monitor_update();
					let (commitment_update, pending_forwards, pending_failures, closing_signed, monitor_update, htlcs_to_fail_in) =
						break_chan_entry!(self, chan.get_mut().revoke_and_ack(&msg, &self.fee_estimator, &self.logger), channel_state, chan);
					htlcs_to_fail = htlcs_to_fail_in;
					if let Err(e) = self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), monitor_update) {
						if was_frozen_for_monitor {
							assert!(commitment_update.is_none() && closing_signed.is_none() && pending_forwards.is_empty() && pending_failures.is_empty());
							break Err(MsgHandleErrInternal::ignore_no_close("Previous monitor update failure prevented responses to RAA".to_owned()));
						} else {
							if let Err(e) = handle_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::CommitmentFirst, false, commitment_update.is_some(), pending_forwards, pending_failures) {
								break Err(e);
							} else { unreachable!(); }
						}
					}
					if let Some(updates) = commitment_update {
						channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
							node_id: counterparty_node_id.clone(),
							updates,
						});
					}
					if let Some(msg) = closing_signed {
						channel_state.pending_msg_events.push(events::MessageSendEvent::SendClosingSigned {
							node_id: counterparty_node_id.clone(),
							msg,
						});
					}
					break Ok((pending_forwards, pending_failures, chan.get().get_short_channel_id().expect("RAA should only work on a short-id-available channel"), chan.get().get_funding_txo().unwrap()))
				},
				hash_map::Entry::Vacant(_) => break Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
			}
		};
		self.fail_holding_cell_htlcs(htlcs_to_fail, msg.channel_id);
		match res {
			Ok((pending_forwards, mut pending_failures, short_channel_id, channel_outpoint)) => {
				for failure in pending_failures.drain(..) {
					self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), failure.0, &failure.1, failure.2);
				}
				self.forward_htlcs(&mut [(short_channel_id, channel_outpoint, pending_forwards)]);
				Ok(())
			},
			Err(e) => Err(e)
		}
	}

	fn internal_update_fee(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFee) -> Result<(), MsgHandleErrInternal> {
		let mut channel_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_lock;
		match channel_state.by_id.entry(msg.channel_id) {
			hash_map::Entry::Occupied(mut chan) => {
				if chan.get().get_counterparty_node_id() != *counterparty_node_id {
					return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
				}
				try_chan_entry!(self, chan.get_mut().update_fee(&self.fee_estimator, &msg), channel_state, chan);
			},
			hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
		}
		Ok(())
	}

	fn internal_announcement_signatures(&self, counterparty_node_id: &PublicKey, msg: &msgs::AnnouncementSignatures) -> Result<(), MsgHandleErrInternal> {
		let mut channel_state_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_state_lock;

		match channel_state.by_id.entry(msg.channel_id) {
			hash_map::Entry::Occupied(mut chan) => {
				if chan.get().get_counterparty_node_id() != *counterparty_node_id {
					return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
				}
				if !chan.get().is_usable() {
					return Err(MsgHandleErrInternal::from_no_close(LightningError{err: "Got an announcement_signatures before we were ready for it".to_owned(), action: msgs::ErrorAction::IgnoreError}));
				}

				channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelAnnouncement {
					msg: try_chan_entry!(self, chan.get_mut().announcement_signatures(&self.our_network_key, self.get_our_node_id(), self.genesis_hash.clone(), msg), channel_state, chan),
					// Note that announcement_signatures fails if the channel cannot be announced,
					// so get_channel_update_for_broadcast will never fail by the time we get here.
					update_msg: self.get_channel_update_for_broadcast(chan.get()).unwrap(),
				});
			},
			hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
		}
		Ok(())
	}

	/// Returns ShouldPersist if anything changed, otherwise either SkipPersist or an Err.
	fn internal_channel_update(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelUpdate) -> Result<NotifyOption, MsgHandleErrInternal> {
		let mut channel_state_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_state_lock;
		let chan_id = match channel_state.short_to_id.get(&msg.contents.short_channel_id) {
			Some(chan_id) => chan_id.clone(),
			None => {
				// It's not a local channel
				return Ok(NotifyOption::SkipPersist)
			}
		};
		match channel_state.by_id.entry(chan_id) {
			hash_map::Entry::Occupied(mut chan) => {
				if chan.get().get_counterparty_node_id() != *counterparty_node_id {
					if chan.get().should_announce() {
						// If the announcement is about a channel of ours which is public, some
						// other peer may simply be forwarding all its gossip to us. Don't provide
						// a scary-looking error message and return Ok instead.
						return Ok(NotifyOption::SkipPersist);
					}
					return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a channel_update for a channel from the wrong node - it shouldn't know about our private channels!".to_owned(), chan_id));
				}
				let were_node_one = self.get_our_node_id().serialize()[..] < chan.get().get_counterparty_node_id().serialize()[..];
				let msg_from_node_one = msg.contents.flags & 1 == 0;
				if were_node_one == msg_from_node_one {
					return Ok(NotifyOption::SkipPersist);
				} else {
					try_chan_entry!(self, chan.get_mut().channel_update(&msg), channel_state, chan);
				}
			},
			hash_map::Entry::Vacant(_) => unreachable!()
		}
		Ok(NotifyOption::DoPersist)
	}

	fn internal_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) -> Result<(), MsgHandleErrInternal> {
		let chan_restoration_res;
		let (htlcs_failed_forward, need_lnd_workaround) = {
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;

			match channel_state.by_id.entry(msg.channel_id) {
				hash_map::Entry::Occupied(mut chan) => {
					if chan.get().get_counterparty_node_id() != *counterparty_node_id {
						return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
					}
					// Currently, we expect all holding cell update_adds to be dropped on peer
					// disconnect, so Channel's reestablish will never hand us any holding cell
					// freed HTLCs to fail backwards. If in the future we no longer drop pending
					// add-HTLCs on disconnect, we may be handed HTLCs to fail backwards here.
					let (funding_locked, revoke_and_ack, commitment_update, monitor_update_opt, order, htlcs_failed_forward, shutdown) =
						try_chan_entry!(self, chan.get_mut().channel_reestablish(msg, &self.logger), channel_state, chan);
					let mut channel_update = None;
					if let Some(msg) = shutdown {
						channel_state.pending_msg_events.push(events::MessageSendEvent::SendShutdown {
							node_id: counterparty_node_id.clone(),
							msg,
						});
					} else if chan.get().is_usable() {
						// If the channel is in a usable state (ie the channel is not being shut
						// down), send a unicast channel_update to our counterparty to make sure
						// they have the latest channel parameters.
						channel_update = Some(events::MessageSendEvent::SendChannelUpdate {
							node_id: chan.get().get_counterparty_node_id(),
							msg: self.get_channel_update_for_unicast(chan.get()).unwrap(),
						});
					}
					let need_lnd_workaround = chan.get_mut().workaround_lnd_bug_4006.take();
					chan_restoration_res = handle_chan_restoration_locked!(self, channel_state_lock, channel_state, chan, revoke_and_ack, commitment_update, order, monitor_update_opt, Vec::new(), None, funding_locked);
					if let Some(upd) = channel_update {
						channel_state.pending_msg_events.push(upd);
					}
					(htlcs_failed_forward, need_lnd_workaround)
				},
				hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
			}
		};
		post_handle_chan_restoration!(self, chan_restoration_res);
		self.fail_holding_cell_htlcs(htlcs_failed_forward, msg.channel_id);

		if let Some(funding_locked_msg) = need_lnd_workaround {
			self.internal_funding_locked(counterparty_node_id, &funding_locked_msg)?;
		}
		Ok(())
	}

	/// Begin Update fee process. Allowed only on an outbound channel.
	/// If successful, will generate a UpdateHTLCs event, so you should probably poll
	/// PeerManager::process_events afterwards.
	/// Note: This API is likely to change!
	/// (C-not exported) Cause its doc(hidden) anyway
	#[doc(hidden)]
	pub fn update_fee(&self, channel_id: [u8;32], feerate_per_kw: u32) -> Result<(), APIError> {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let counterparty_node_id;
		let err: Result<(), _> = loop {
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;

			match channel_state.by_id.entry(channel_id) {
				hash_map::Entry::Vacant(_) => return Err(APIError::APIMisuseError{err: format!("Failed to find corresponding channel for id {}", channel_id.to_hex())}),
				hash_map::Entry::Occupied(mut chan) => {
					if !chan.get().is_outbound() {
						return Err(APIError::APIMisuseError{err: "update_fee cannot be sent for an inbound channel".to_owned()});
					}
					if chan.get().is_awaiting_monitor_update() {
						return Err(APIError::MonitorUpdateFailed);
					}
					if !chan.get().is_live() {
						return Err(APIError::ChannelUnavailable{err: "Channel is either not yet fully established or peer is currently disconnected".to_owned()});
					}
					counterparty_node_id = chan.get().get_counterparty_node_id();
					if let Some((update_fee, commitment_signed, monitor_update)) =
							break_chan_entry!(self, chan.get_mut().send_update_fee_and_commit(feerate_per_kw, &self.logger), channel_state, chan)
					{
						if let Err(_e) = self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), monitor_update) {
							unimplemented!();
						}
						log_debug!(self.logger, "Updating fee resulted in a commitment_signed for channel {}", log_bytes!(chan.get().channel_id()));
						channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
							node_id: chan.get().get_counterparty_node_id(),
							updates: msgs::CommitmentUpdate {
								update_add_htlcs: Vec::new(),
								update_fulfill_htlcs: Vec::new(),
								update_fail_htlcs: Vec::new(),
								update_fail_malformed_htlcs: Vec::new(),
								update_fee: Some(update_fee),
								commitment_signed,
							},
						});
					}
				},
			}
			return Ok(())
		};

		match handle_error!(self, err, counterparty_node_id) {
			Ok(_) => unreachable!(),
			Err(e) => { Err(APIError::APIMisuseError { err: e.err })}
		}
	}

	/// Process pending events from the `chain::Watch`, returning whether any events were processed.
	fn process_pending_monitor_events(&self) -> bool {
		let mut failed_channels = Vec::new();
		let pending_monitor_events = self.chain_monitor.release_pending_monitor_events();
		let has_pending_monitor_events = !pending_monitor_events.is_empty();
		for monitor_event in pending_monitor_events {
			match monitor_event {
				MonitorEvent::HTLCEvent(htlc_update) => {
					if let Some(preimage) = htlc_update.payment_preimage {
						log_trace!(self.logger, "Claiming HTLC with preimage {} from our monitor", log_bytes!(preimage.0));
						self.claim_funds_internal(self.channel_state.lock().unwrap(), htlc_update.source, preimage);
					} else {
						log_trace!(self.logger, "Failing HTLC with hash {} from our monitor", log_bytes!(htlc_update.payment_hash.0));
						self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_update.source, &htlc_update.payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() });
					}
				},
				MonitorEvent::CommitmentTxBroadcasted(funding_outpoint) => {
					let mut channel_lock = self.channel_state.lock().unwrap();
					let channel_state = &mut *channel_lock;
					let by_id = &mut channel_state.by_id;
					let short_to_id = &mut channel_state.short_to_id;
					let pending_msg_events = &mut channel_state.pending_msg_events;
					if let Some(mut chan) = by_id.remove(&funding_outpoint.to_channel_id()) {
						if let Some(short_id) = chan.get_short_channel_id() {
							short_to_id.remove(&short_id);
						}
						failed_channels.push(chan.force_shutdown(false));
						if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
							pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
								msg: update
							});
						}
						pending_msg_events.push(events::MessageSendEvent::HandleError {
							node_id: chan.get_counterparty_node_id(),
							action: msgs::ErrorAction::SendErrorMessage {
								msg: msgs::ErrorMessage { channel_id: chan.channel_id(), data: "Channel force-closed".to_owned() }
							},
						});
					}
				},
			}
		}

		for failure in failed_channels.drain(..) {
			self.finish_force_close_channel(failure);
		}

		has_pending_monitor_events
	}

	/// Check the holding cell in each channel and free any pending HTLCs in them if possible.
	/// Returns whether there were any updates such as if pending HTLCs were freed or a monitor
	/// update was applied.
	///
	/// This should only apply to HTLCs which were added to the holding cell because we were
	/// waiting on a monitor update to finish. In that case, we don't want to free the holding cell
	/// directly in `channel_monitor_updated` as it may introduce deadlocks calling back into user
	/// code to inform them of a channel monitor update.
	fn check_free_holding_cells(&self) -> bool {
		let mut has_monitor_update = false;
		let mut failed_htlcs = Vec::new();
		let mut handle_errors = Vec::new();
		{
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;
			let by_id = &mut channel_state.by_id;
			let short_to_id = &mut channel_state.short_to_id;
			let pending_msg_events = &mut channel_state.pending_msg_events;

			by_id.retain(|channel_id, chan| {
				match chan.maybe_free_holding_cell_htlcs(&self.logger) {
					Ok((commitment_opt, holding_cell_failed_htlcs)) => {
						if !holding_cell_failed_htlcs.is_empty() {
							failed_htlcs.push((holding_cell_failed_htlcs, *channel_id));
						}
						if let Some((commitment_update, monitor_update)) = commitment_opt {
							if let Err(e) = self.chain_monitor.update_channel(chan.get_funding_txo().unwrap(), monitor_update) {
								has_monitor_update = true;
								let (res, close_channel) = handle_monitor_err!(self, e, short_to_id, chan, RAACommitmentOrder::CommitmentFirst, false, true, Vec::new(), Vec::new(), channel_id);
								handle_errors.push((chan.get_counterparty_node_id(), res));
								if close_channel { return false; }
							} else {
								pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
									node_id: chan.get_counterparty_node_id(),
									updates: commitment_update,
								});
							}
						}
						true
					},
					Err(e) => {
						let (close_channel, res) = convert_chan_err!(self, e, short_to_id, chan, channel_id);
						handle_errors.push((chan.get_counterparty_node_id(), Err(res)));
						!close_channel
					}
				}
			});
		}

		let has_update = has_monitor_update || !failed_htlcs.is_empty();
		for (failures, channel_id) in failed_htlcs.drain(..) {
			self.fail_holding_cell_htlcs(failures, channel_id);
		}

		for (counterparty_node_id, err) in handle_errors.drain(..) {
			let _ = handle_error!(self, err, counterparty_node_id);
		}

		has_update
	}

	/// Handle a list of channel failures during a block_connected or block_disconnected call,
	/// pushing the channel monitor update (if any) to the background events queue and removing the
	/// Channel object.
	fn handle_init_event_channel_failures(&self, mut failed_channels: Vec<ShutdownResult>) {
		for mut failure in failed_channels.drain(..) {
			// Either a commitment transactions has been confirmed on-chain or
			// Channel::block_disconnected detected that the funding transaction has been
			// reorganized out of the main chain.
			// We cannot broadcast our latest local state via monitor update (as
			// Channel::force_shutdown tries to make us do) as we may still be in initialization,
			// so we track the update internally and handle it when the user next calls
			// timer_tick_occurred, guaranteeing we're running normally.
			if let Some((funding_txo, update)) = failure.0.take() {
				assert_eq!(update.updates.len(), 1);
				if let ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } = update.updates[0] {
					assert!(should_broadcast);
				} else { unreachable!(); }
				self.pending_background_events.lock().unwrap().push(BackgroundEvent::ClosingMonitorUpdate((funding_txo, update)));
			}
			self.finish_force_close_channel(failure);
		}
	}

	fn set_payment_hash_secret_map(&self, payment_hash: PaymentHash, payment_preimage: Option<PaymentPreimage>, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32, user_payment_id: u64) -> Result<PaymentSecret, APIError> {
		assert!(invoice_expiry_delta_secs <= 60*60*24*365); // Sadly bitcoin timestamps are u32s, so panic before 2106

		let payment_secret = PaymentSecret(self.keys_manager.get_secure_random_bytes());

		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let mut payment_secrets = self.pending_inbound_payments.lock().unwrap();
		match payment_secrets.entry(payment_hash) {
			hash_map::Entry::Vacant(e) => {
				e.insert(PendingInboundPayment {
					payment_secret, min_value_msat, user_payment_id, payment_preimage,
					// We assume that highest_seen_timestamp is pretty close to the current time -
					// its updated when we receive a new block with the maximum time we've seen in
					// a header. It should never be more than two hours in the future.
					// Thus, we add two hours here as a buffer to ensure we absolutely
					// never fail a payment too early.
					// Note that we assume that received blocks have reasonably up-to-date
					// timestamps.
					expiry_time: self.highest_seen_timestamp.load(Ordering::Acquire) as u64 + invoice_expiry_delta_secs as u64 + 7200,
				});
			},
			hash_map::Entry::Occupied(_) => return Err(APIError::APIMisuseError { err: "Duplicate payment hash".to_owned() }),
		}
		Ok(payment_secret)
	}

	/// Gets a payment secret and payment hash for use in an invoice given to a third party wishing
	/// to pay us.
	///
	/// This differs from [`create_inbound_payment_for_hash`] only in that it generates the
	/// [`PaymentHash`] and [`PaymentPreimage`] for you, returning the first and storing the second.
	///
	/// The [`PaymentPreimage`] will ultimately be returned to you in the [`PaymentReceived`], which
	/// will have the [`PaymentReceived::payment_preimage`] field filled in. That should then be
	/// passed directly to [`claim_funds`].
	///
	/// See [`create_inbound_payment_for_hash`] for detailed documentation on behavior and requirements.
	///
	/// [`claim_funds`]: Self::claim_funds
	/// [`PaymentReceived`]: events::Event::PaymentReceived
	/// [`PaymentReceived::payment_preimage`]: events::Event::PaymentReceived::payment_preimage
	/// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash
	pub fn create_inbound_payment(&self, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32, user_payment_id: u64) -> (PaymentHash, PaymentSecret) {
		let payment_preimage = PaymentPreimage(self.keys_manager.get_secure_random_bytes());
		let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());

		(payment_hash,
			self.set_payment_hash_secret_map(payment_hash, Some(payment_preimage), min_value_msat, invoice_expiry_delta_secs, user_payment_id)
				.expect("RNG Generated Duplicate PaymentHash"))
	}

	/// Gets a [`PaymentSecret`] for a given [`PaymentHash`], for which the payment preimage is
	/// stored external to LDK.
	///
	/// A [`PaymentReceived`] event will only be generated if the [`PaymentSecret`] matches a
	/// payment secret fetched via this method or [`create_inbound_payment`], and which is at least
	/// the `min_value_msat` provided here, if one is provided.
	///
	/// The [`PaymentHash`] (and corresponding [`PaymentPreimage`]) must be globally unique. This
	/// method may return an Err if another payment with the same payment_hash is still pending.
	///
	/// `user_payment_id` will be provided back in [`PaymentReceived::user_payment_id`] events to
	/// allow tracking of which events correspond with which calls to this and
	/// [`create_inbound_payment`]. `user_payment_id` has no meaning inside of LDK, it is simply
	/// copied to events and otherwise ignored. It may be used to correlate PaymentReceived events
	/// with invoice metadata stored elsewhere.
	///
	/// `min_value_msat` should be set if the invoice being generated contains a value. Any payment
	/// received for the returned [`PaymentHash`] will be required to be at least `min_value_msat`
	/// before a [`PaymentReceived`] event will be generated, ensuring that we do not provide the
	/// sender "proof-of-payment" unless they have paid the required amount.
	///
	/// `invoice_expiry_delta_secs` describes the number of seconds that the invoice is valid for
	/// in excess of the current time. This should roughly match the expiry time set in the invoice.
	/// After this many seconds, we will remove the inbound payment, resulting in any attempts to
	/// pay the invoice failing. The BOLT spec suggests 3,600 secs as a default validity time for
	/// invoices when no timeout is set.
	///
	/// Note that we use block header time to time-out pending inbound payments (with some margin
	/// to compensate for the inaccuracy of block header timestamps). Thus, in practice we will
	/// accept a payment and generate a [`PaymentReceived`] event for some time after the expiry.
	/// If you need exact expiry semantics, you should enforce them upon receipt of
	/// [`PaymentReceived`].
	///
	/// Pending inbound payments are stored in memory and in serialized versions of this
	/// [`ChannelManager`]. If potentially unbounded numbers of inbound payments may exist and
	/// space is limited, you may wish to rate-limit inbound payment creation.
	///
	/// May panic if `invoice_expiry_delta_secs` is greater than one year.
	///
	/// Note that invoices generated for inbound payments should have their `min_final_cltv_expiry`
	/// set to at least [`MIN_FINAL_CLTV_EXPIRY`].
	///
	/// [`create_inbound_payment`]: Self::create_inbound_payment
	/// [`PaymentReceived`]: events::Event::PaymentReceived
	/// [`PaymentReceived::user_payment_id`]: events::Event::PaymentReceived::user_payment_id
	pub fn create_inbound_payment_for_hash(&self, payment_hash: PaymentHash, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32, user_payment_id: u64) -> Result<PaymentSecret, APIError> {
		self.set_payment_hash_secret_map(payment_hash, None, min_value_msat, invoice_expiry_delta_secs, user_payment_id)
	}

	#[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
	pub fn get_and_clear_pending_events(&self) -> Vec<events::Event> {
		let events = core::cell::RefCell::new(Vec::new());
		let event_handler = |event| events.borrow_mut().push(event);
		self.process_pending_events(&event_handler);
		events.into_inner()
	}
}

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> MessageSendEventsProvider for ChannelManager<Signer, M, T, K, F, L>
	where M::Target: chain::Watch<Signer>,
        T::Target: BroadcasterInterface,
        K::Target: KeysInterface<Signer = Signer>,
        F::Target: FeeEstimator,
				L::Target: Logger,
{
	fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent> {
		let events = RefCell::new(Vec::new());
		PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
			let mut result = NotifyOption::SkipPersist;

			// TODO: This behavior should be documented. It's unintuitive that we query
			// ChannelMonitors when clearing other events.
			if self.process_pending_monitor_events() {
				result = NotifyOption::DoPersist;
			}

			if self.check_free_holding_cells() {
				result = NotifyOption::DoPersist;
			}

			let mut pending_events = Vec::new();
			let mut channel_state = self.channel_state.lock().unwrap();
			mem::swap(&mut pending_events, &mut channel_state.pending_msg_events);

			if !pending_events.is_empty() {
				events.replace(pending_events);
			}

			result
		});
		events.into_inner()
	}
}

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> EventsProvider for ChannelManager<Signer, M, T, K, F, L>
where
	M::Target: chain::Watch<Signer>,
	T::Target: BroadcasterInterface,
	K::Target: KeysInterface<Signer = Signer>,
	F::Target: FeeEstimator,
	L::Target: Logger,
{
	/// Processes events that must be periodically handled.
	///
	/// An [`EventHandler`] may safely call back to the provider in order to handle an event.
	/// However, it must not call [`Writeable::write`] as doing so would result in a deadlock.
	///
	/// Pending events are persisted as part of [`ChannelManager`]. While these events are cleared
	/// when processed, an [`EventHandler`] must be able to handle previously seen events when
	/// restarting from an old state.
	fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler {
		PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
			let mut result = NotifyOption::SkipPersist;

			// TODO: This behavior should be documented. It's unintuitive that we query
			// ChannelMonitors when clearing other events.
			if self.process_pending_monitor_events() {
				result = NotifyOption::DoPersist;
			}

			let mut pending_events = std::mem::replace(&mut *self.pending_events.lock().unwrap(), vec![]);
			if !pending_events.is_empty() {
				result = NotifyOption::DoPersist;
			}

			for event in pending_events.drain(..) {
				handler.handle_event(event);
			}

			result
		});
	}
}

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> chain::Listen for ChannelManager<Signer, M, T, K, F, L>
where
	M::Target: chain::Watch<Signer>,
	T::Target: BroadcasterInterface,
	K::Target: KeysInterface<Signer = Signer>,
	F::Target: FeeEstimator,
	L::Target: Logger,
{
	fn block_connected(&self, block: &Block, height: u32) {
		{
			let best_block = self.best_block.read().unwrap();
			assert_eq!(best_block.block_hash(), block.header.prev_blockhash,
				"Blocks must be connected in chain-order - the connected header must build on the last connected header");
			assert_eq!(best_block.height(), height - 1,
				"Blocks must be connected in chain-order - the connected block height must be one greater than the previous height");
		}

		let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
		self.transactions_confirmed(&block.header, &txdata, height);
		self.best_block_updated(&block.header, height);
	}

	fn block_disconnected(&self, header: &BlockHeader, height: u32) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let new_height = height - 1;
		{
			let mut best_block = self.best_block.write().unwrap();
			assert_eq!(best_block.block_hash(), header.block_hash(),
				"Blocks must be disconnected in chain-order - the disconnected header must be the last connected header");
			assert_eq!(best_block.height(), height,
				"Blocks must be disconnected in chain-order - the disconnected block must have the correct height");
			*best_block = BestBlock::new(header.prev_blockhash, new_height)
		}

		self.do_chain_event(Some(new_height), |channel| channel.best_block_updated(new_height, header.time, &self.logger));
	}
}

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> chain::Confirm for ChannelManager<Signer, M, T, K, F, L>
where
	M::Target: chain::Watch<Signer>,
	T::Target: BroadcasterInterface,
	K::Target: KeysInterface<Signer = Signer>,
	F::Target: FeeEstimator,
	L::Target: Logger,
{
	fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
		// Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
		// during initialization prior to the chain_monitor being fully configured in some cases.
		// See the docs for `ChannelManagerReadArgs` for more.

		let block_hash = header.block_hash();
		log_trace!(self.logger, "{} transactions included in block {} at height {} provided", txdata.len(), block_hash, height);

		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		self.do_chain_event(Some(height), |channel| channel.transactions_confirmed(&block_hash, height, txdata, &self.logger).map(|a| (a, Vec::new())));
	}

	fn best_block_updated(&self, header: &BlockHeader, height: u32) {
		// Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
		// during initialization prior to the chain_monitor being fully configured in some cases.
		// See the docs for `ChannelManagerReadArgs` for more.

		let block_hash = header.block_hash();
		log_trace!(self.logger, "New best block: {} at height {}", block_hash, height);

		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		*self.best_block.write().unwrap() = BestBlock::new(block_hash, height);

		self.do_chain_event(Some(height), |channel| channel.best_block_updated(height, header.time, &self.logger));

		macro_rules! max_time {
			($timestamp: expr) => {
				loop {
					// Update $timestamp to be the max of its current value and the block
					// timestamp. This should keep us close to the current time without relying on
					// having an explicit local time source.
					// Just in case we end up in a race, we loop until we either successfully
					// update $timestamp or decide we don't need to.
					let old_serial = $timestamp.load(Ordering::Acquire);
					if old_serial >= header.time as usize { break; }
					if $timestamp.compare_exchange(old_serial, header.time as usize, Ordering::AcqRel, Ordering::Relaxed).is_ok() {
						break;
					}
				}
			}
		}
		max_time!(self.last_node_announcement_serial);
		max_time!(self.highest_seen_timestamp);
		let mut payment_secrets = self.pending_inbound_payments.lock().unwrap();
		payment_secrets.retain(|_, inbound_payment| {
			inbound_payment.expiry_time > header.time as u64
		});
	}

	fn get_relevant_txids(&self) -> Vec<Txid> {
		let channel_state = self.channel_state.lock().unwrap();
		let mut res = Vec::with_capacity(channel_state.short_to_id.len());
		for chan in channel_state.by_id.values() {
			if let Some(funding_txo) = chan.get_funding_txo() {
				res.push(funding_txo.txid);
			}
		}
		res
	}

	fn transaction_unconfirmed(&self, txid: &Txid) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		self.do_chain_event(None, |channel| {
			if let Some(funding_txo) = channel.get_funding_txo() {
				if funding_txo.txid == *txid {
					channel.funding_transaction_unconfirmed(&self.logger).map(|_| (None, Vec::new()))
				} else { Ok((None, Vec::new())) }
			} else { Ok((None, Vec::new())) }
		});
	}
}

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<Signer, M, T, K, F, L>
where
	M::Target: chain::Watch<Signer>,
	T::Target: BroadcasterInterface,
	K::Target: KeysInterface<Signer = Signer>,
	F::Target: FeeEstimator,
	L::Target: Logger,
{
	/// Calls a function which handles an on-chain event (blocks dis/connected, transactions
	/// un/confirmed, etc) on each channel, handling any resulting errors or messages generated by
	/// the function.
	fn do_chain_event<FN: Fn(&mut Channel<Signer>) -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>), msgs::ErrorMessage>>
			(&self, height_opt: Option<u32>, f: FN) {
		// Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
		// during initialization prior to the chain_monitor being fully configured in some cases.
		// See the docs for `ChannelManagerReadArgs` for more.

		let mut failed_channels = Vec::new();
		let mut timed_out_htlcs = Vec::new();
		{
			let mut channel_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_lock;
			let short_to_id = &mut channel_state.short_to_id;
			let pending_msg_events = &mut channel_state.pending_msg_events;
			channel_state.by_id.retain(|_, channel| {
				let res = f(channel);
				if let Ok((chan_res, mut timed_out_pending_htlcs)) = res {
					for (source, payment_hash) in timed_out_pending_htlcs.drain(..) {
						let chan_update = self.get_channel_update_for_unicast(&channel).map(|u| u.encode_with_len()).unwrap(); // Cannot add/recv HTLCs before we have a short_id so unwrap is safe
						timed_out_htlcs.push((source, payment_hash,  HTLCFailReason::Reason {
							failure_code: 0x1000 | 14, // expiry_too_soon, or at least it is now
							data: chan_update,
						}));
					}
					if let Some(funding_locked) = chan_res {
						pending_msg_events.push(events::MessageSendEvent::SendFundingLocked {
							node_id: channel.get_counterparty_node_id(),
							msg: funding_locked,
						});
						if let Some(announcement_sigs) = self.get_announcement_sigs(channel) {
							log_trace!(self.logger, "Sending funding_locked and announcement_signatures for {}", log_bytes!(channel.channel_id()));
							pending_msg_events.push(events::MessageSendEvent::SendAnnouncementSignatures {
								node_id: channel.get_counterparty_node_id(),
								msg: announcement_sigs,
							});
						} else if channel.is_usable() {
							log_trace!(self.logger, "Sending funding_locked WITHOUT announcement_signatures but with private channel_update for our counterparty on channel {}", log_bytes!(channel.channel_id()));
							pending_msg_events.push(events::MessageSendEvent::SendChannelUpdate {
								node_id: channel.get_counterparty_node_id(),
								msg: self.get_channel_update_for_unicast(channel).unwrap(),
							});
						} else {
							log_trace!(self.logger, "Sending funding_locked WITHOUT announcement_signatures for {}", log_bytes!(channel.channel_id()));
						}
						short_to_id.insert(channel.get_short_channel_id().unwrap(), channel.channel_id());
					}
				} else if let Err(e) = res {
					if let Some(short_id) = channel.get_short_channel_id() {
						short_to_id.remove(&short_id);
					}
					// It looks like our counterparty went on-chain or funding transaction was
					// reorged out of the main chain. Close the channel.
					failed_channels.push(channel.force_shutdown(true));
					if let Ok(update) = self.get_channel_update_for_broadcast(&channel) {
						pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
							msg: update
						});
					}
					pending_msg_events.push(events::MessageSendEvent::HandleError {
						node_id: channel.get_counterparty_node_id(),
						action: msgs::ErrorAction::SendErrorMessage { msg: e },
					});
					return false;
				}
				true
			});

			if let Some(height) = height_opt {
				channel_state.claimable_htlcs.retain(|payment_hash, htlcs| {
					htlcs.retain(|htlc| {
						// If height is approaching the number of blocks we think it takes us to get
						// our commitment transaction confirmed before the HTLC expires, plus the
						// number of blocks we generally consider it to take to do a commitment update,
						// just give up on it and fail the HTLC.
						if height >= htlc.cltv_expiry - HTLC_FAIL_BACK_BUFFER {
							let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
							htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(height));
							timed_out_htlcs.push((HTLCSource::PreviousHopData(htlc.prev_hop.clone()), payment_hash.clone(), HTLCFailReason::Reason {
								failure_code: 0x4000 | 15,
								data: htlc_msat_height_data
							}));
							false
						} else { true }
					});
					!htlcs.is_empty() // Only retain this entry if htlcs has at least one entry.
				});
			}
		}

		self.handle_init_event_channel_failures(failed_channels);

		for (source, payment_hash, reason) in timed_out_htlcs.drain(..) {
			self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), source, &payment_hash, reason);
		}
	}

	/// Blocks until ChannelManager needs to be persisted or a timeout is reached. It returns a bool
	/// indicating whether persistence is necessary. Only one listener on
	/// `await_persistable_update` or `await_persistable_update_timeout` is guaranteed to be woken
	/// up.
	/// Note that the feature `allow_wallclock_use` must be enabled to use this function.
	#[cfg(any(test, feature = "allow_wallclock_use"))]
	pub fn await_persistable_update_timeout(&self, max_wait: Duration) -> bool {
		self.persistence_notifier.wait_timeout(max_wait)
	}

	/// Blocks until ChannelManager needs to be persisted. Only one listener on
	/// `await_persistable_update` or `await_persistable_update_timeout` is guaranteed to be woken
	/// up.
	pub fn await_persistable_update(&self) {
		self.persistence_notifier.wait()
	}

	#[cfg(any(test, feature = "_test_utils"))]
	pub fn get_persistence_condvar_value(&self) -> bool {
		let mutcond = &self.persistence_notifier.persistence_lock;
		let &(ref mtx, _) = mutcond;
		let guard = mtx.lock().unwrap();
		*guard
	}

	/// Gets the latest best block which was connected either via the [`chain::Listen`] or
	/// [`chain::Confirm`] interfaces.
	pub fn current_best_block(&self) -> BestBlock {
		self.best_block.read().unwrap().clone()
	}
}

impl<Signer: Sign, M: Deref , T: Deref , K: Deref , F: Deref , L: Deref >
	ChannelMessageHandler for ChannelManager<Signer, M, T, K, F, L>
	where M::Target: chain::Watch<Signer>,
        T::Target: BroadcasterInterface,
        K::Target: KeysInterface<Signer = Signer>,
        F::Target: FeeEstimator,
        L::Target: Logger,
{
	fn handle_open_channel(&self, counterparty_node_id: &PublicKey, their_features: InitFeatures, msg: &msgs::OpenChannel) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_open_channel(counterparty_node_id, their_features, msg), *counterparty_node_id);
	}

	fn handle_accept_channel(&self, counterparty_node_id: &PublicKey, their_features: InitFeatures, msg: &msgs::AcceptChannel) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_accept_channel(counterparty_node_id, their_features, msg), *counterparty_node_id);
	}

	fn handle_funding_created(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingCreated) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_funding_created(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_funding_signed(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingSigned) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_funding_signed(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_funding_locked(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingLocked) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_funding_locked(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_shutdown(&self, counterparty_node_id: &PublicKey, their_features: &InitFeatures, msg: &msgs::Shutdown) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_shutdown(counterparty_node_id, their_features, msg), *counterparty_node_id);
	}

	fn handle_closing_signed(&self, counterparty_node_id: &PublicKey, msg: &msgs::ClosingSigned) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_closing_signed(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_update_add_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateAddHTLC) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_update_add_htlc(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_update_fulfill_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFulfillHTLC) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_update_fulfill_htlc(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_update_fail_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFailHTLC) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_update_fail_htlc(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_update_fail_malformed_htlc(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFailMalformedHTLC) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_update_fail_malformed_htlc(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_commitment_signed(&self, counterparty_node_id: &PublicKey, msg: &msgs::CommitmentSigned) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_commitment_signed(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_revoke_and_ack(&self, counterparty_node_id: &PublicKey, msg: &msgs::RevokeAndACK) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_revoke_and_ack(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_update_fee(&self, counterparty_node_id: &PublicKey, msg: &msgs::UpdateFee) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_update_fee(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_announcement_signatures(&self, counterparty_node_id: &PublicKey, msg: &msgs::AnnouncementSignatures) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_announcement_signatures(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn handle_channel_update(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelUpdate) {
		PersistenceNotifierGuard::optionally_notify(&self.total_consistency_lock, &self.persistence_notifier, || {
			if let Ok(persist) = handle_error!(self, self.internal_channel_update(counterparty_node_id, msg), *counterparty_node_id) {
				persist
			} else {
				NotifyOption::SkipPersist
			}
		});
	}

	fn handle_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let _ = handle_error!(self, self.internal_channel_reestablish(counterparty_node_id, msg), *counterparty_node_id);
	}

	fn peer_disconnected(&self, counterparty_node_id: &PublicKey, no_connection_possible: bool) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
		let mut failed_channels = Vec::new();
		let mut no_channels_remain = true;
		{
			let mut channel_state_lock = self.channel_state.lock().unwrap();
			let channel_state = &mut *channel_state_lock;
			let short_to_id = &mut channel_state.short_to_id;
			let pending_msg_events = &mut channel_state.pending_msg_events;
			if no_connection_possible {
				log_debug!(self.logger, "Failing all channels with {} due to no_connection_possible", log_pubkey!(counterparty_node_id));
				channel_state.by_id.retain(|_, chan| {
					if chan.get_counterparty_node_id() == *counterparty_node_id {
						if let Some(short_id) = chan.get_short_channel_id() {
							short_to_id.remove(&short_id);
						}
						failed_channels.push(chan.force_shutdown(true));
						if let Ok(update) = self.get_channel_update_for_broadcast(&chan) {
							pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
								msg: update
							});
						}
						false
					} else {
						true
					}
				});
			} else {
				log_debug!(self.logger, "Marking channels with {} disconnected and generating channel_updates", log_pubkey!(counterparty_node_id));
				channel_state.by_id.retain(|_, chan| {
					if chan.get_counterparty_node_id() == *counterparty_node_id {
						chan.remove_uncommitted_htlcs_and_mark_paused(&self.logger);
						if chan.is_shutdown() {
							if let Some(short_id) = chan.get_short_channel_id() {
								short_to_id.remove(&short_id);
							}
							return false;
						} else {
							no_channels_remain = false;
						}
					}
					true
				})
			}
			pending_msg_events.retain(|msg| {
				match msg {
					&events::MessageSendEvent::SendAcceptChannel { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::SendOpenChannel { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::SendFundingCreated { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::SendFundingSigned { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::SendFundingLocked { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::SendAnnouncementSignatures { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::UpdateHTLCs { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::SendRevokeAndACK { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::SendClosingSigned { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::SendShutdown { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::SendChannelReestablish { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::BroadcastChannelAnnouncement { .. } => true,
					&events::MessageSendEvent::BroadcastNodeAnnouncement { .. } => true,
					&events::MessageSendEvent::BroadcastChannelUpdate { .. } => true,
					&events::MessageSendEvent::SendChannelUpdate { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::HandleError { ref node_id, .. } => node_id != counterparty_node_id,
					&events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => true,
					&events::MessageSendEvent::SendChannelRangeQuery { .. } => false,
					&events::MessageSendEvent::SendShortIdsQuery { .. } => false,
					&events::MessageSendEvent::SendReplyChannelRange { .. } => false,
				}
			});
		}
		if no_channels_remain {
			self.per_peer_state.write().unwrap().remove(counterparty_node_id);
		}

		for failure in failed_channels.drain(..) {
			self.finish_force_close_channel(failure);
		}
	}

	fn peer_connected(&self, counterparty_node_id: &PublicKey, init_msg: &msgs::Init) {
		log_debug!(self.logger, "Generating channel_reestablish events for {}", log_pubkey!(counterparty_node_id));

		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		{
			let mut peer_state_lock = self.per_peer_state.write().unwrap();
			match peer_state_lock.entry(counterparty_node_id.clone()) {
				hash_map::Entry::Vacant(e) => {
					e.insert(Mutex::new(PeerState {
						latest_features: init_msg.features.clone(),
					}));
				},
				hash_map::Entry::Occupied(e) => {
					e.get().lock().unwrap().latest_features = init_msg.features.clone();
				},
			}
		}

		let mut channel_state_lock = self.channel_state.lock().unwrap();
		let channel_state = &mut *channel_state_lock;
		let pending_msg_events = &mut channel_state.pending_msg_events;
		channel_state.by_id.retain(|_, chan| {
			if chan.get_counterparty_node_id() == *counterparty_node_id {
				if !chan.have_received_message() {
					// If we created this (outbound) channel while we were disconnected from the
					// peer we probably failed to send the open_channel message, which is now
					// lost. We can't have had anything pending related to this channel, so we just
					// drop it.
					false
				} else {
					pending_msg_events.push(events::MessageSendEvent::SendChannelReestablish {
						node_id: chan.get_counterparty_node_id(),
						msg: chan.get_channel_reestablish(&self.logger),
					});
					true
				}
			} else { true }
		});
		//TODO: Also re-broadcast announcement_signatures
	}

	fn handle_error(&self, counterparty_node_id: &PublicKey, msg: &msgs::ErrorMessage) {
		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);

		if msg.channel_id == [0; 32] {
			for chan in self.list_channels() {
				if chan.counterparty.node_id == *counterparty_node_id {
					// Untrusted messages from peer, we throw away the error if id points to a non-existent channel
					let _ = self.force_close_channel_with_peer(&chan.channel_id, Some(counterparty_node_id));
				}
			}
		} else {
			// Untrusted messages from peer, we throw away the error if id points to a non-existent channel
			let _ = self.force_close_channel_with_peer(&msg.channel_id, Some(counterparty_node_id));
		}
	}
}

/// Used to signal to the ChannelManager persister that the manager needs to be re-persisted to
/// disk/backups, through `await_persistable_update_timeout` and `await_persistable_update`.
struct PersistenceNotifier {
	/// Users won't access the persistence_lock directly, but rather wait on its bool using
	/// `wait_timeout` and `wait`.
	persistence_lock: (Mutex<bool>, Condvar),
}

impl PersistenceNotifier {
	fn new() -> Self {
		Self {
			persistence_lock: (Mutex::new(false), Condvar::new()),
		}
	}

	fn wait(&self) {
		loop {
			let &(ref mtx, ref cvar) = &self.persistence_lock;
			let mut guard = mtx.lock().unwrap();
			if *guard {
				*guard = false;
				return;
			}
			guard = cvar.wait(guard).unwrap();
			let result = *guard;
			if result {
				*guard = false;
				return
			}
		}
	}

	#[cfg(any(test, feature = "allow_wallclock_use"))]
	fn wait_timeout(&self, max_wait: Duration) -> bool {
		let current_time = Instant::now();
		loop {
			let &(ref mtx, ref cvar) = &self.persistence_lock;
			let mut guard = mtx.lock().unwrap();
			if *guard {
				*guard = false;
				return true;
			}
			guard = cvar.wait_timeout(guard, max_wait).unwrap().0;
			// Due to spurious wakeups that can happen on `wait_timeout`, here we need to check if the
			// desired wait time has actually passed, and if not then restart the loop with a reduced wait
			// time. Note that this logic can be highly simplified through the use of
			// `Condvar::wait_while` and `Condvar::wait_timeout_while`, if and when our MSRV is raised to
			// 1.42.0.
			let elapsed = current_time.elapsed();
			let result = *guard;
			if result || elapsed >= max_wait {
				*guard = false;
				return result;
			}
			match max_wait.checked_sub(elapsed) {
				None => return result,
				Some(_) => continue
			}
		}
	}

	// Signal to the ChannelManager persister that there are updates necessitating persisting to disk.
	fn notify(&self) {
		let &(ref persist_mtx, ref cnd) = &self.persistence_lock;
		let mut persistence_lock = persist_mtx.lock().unwrap();
		*persistence_lock = true;
		mem::drop(persistence_lock);
		cnd.notify_all();
	}
}

const SERIALIZATION_VERSION: u8 = 1;
const MIN_SERIALIZATION_VERSION: u8 = 1;

impl_writeable_tlv_based_enum!(PendingHTLCRouting,
	(0, Forward) => {
		(0, onion_packet, required),
		(2, short_channel_id, required),
	},
	(1, Receive) => {
		(0, payment_data, required),
		(2, incoming_cltv_expiry, required),
	}
;);

impl_writeable_tlv_based!(PendingHTLCInfo, {
	(0, routing, required),
	(2, incoming_shared_secret, required),
	(4, payment_hash, required),
	(6, amt_to_forward, required),
	(8, outgoing_cltv_value, required)
});

impl_writeable_tlv_based_enum!(HTLCFailureMsg, ;
	(0, Relay),
	(1, Malformed),
);
impl_writeable_tlv_based_enum!(PendingHTLCStatus, ;
	(0, Forward),
	(1, Fail),
);

impl_writeable_tlv_based!(HTLCPreviousHopData, {
	(0, short_channel_id, required),
	(2, outpoint, required),
	(4, htlc_id, required),
	(6, incoming_packet_shared_secret, required)
});

impl_writeable_tlv_based!(ClaimableHTLC, {
	(0, prev_hop, required),
	(2, value, required),
	(4, payment_data, required),
	(6, cltv_expiry, required),
});

impl_writeable_tlv_based_enum!(HTLCSource,
	(0, OutboundRoute) => {
		(0, session_priv, required),
		(2, first_hop_htlc_msat, required),
		(4, path, vec_type),
	}, ;
	(1, PreviousHopData)
);

impl_writeable_tlv_based_enum!(HTLCFailReason,
	(0, LightningError) => {
		(0, err, required),
	},
	(1, Reason) => {
		(0, failure_code, required),
		(2, data, vec_type),
	},
;);

impl_writeable_tlv_based_enum!(HTLCForwardInfo,
	(0, AddHTLC) => {
		(0, forward_info, required),
		(2, prev_short_channel_id, required),
		(4, prev_htlc_id, required),
		(6, prev_funding_outpoint, required),
	},
	(1, FailHTLC) => {
		(0, htlc_id, required),
		(2, err_packet, required),
	},
;);

impl_writeable_tlv_based!(PendingInboundPayment, {
	(0, payment_secret, required),
	(2, expiry_time, required),
	(4, user_payment_id, required),
	(6, payment_preimage, required),
	(8, min_value_msat, required),
});

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable for ChannelManager<Signer, M, T, K, F, L>
	where M::Target: chain::Watch<Signer>,
        T::Target: BroadcasterInterface,
        K::Target: KeysInterface<Signer = Signer>,
        F::Target: FeeEstimator,
        L::Target: Logger,
{
	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
		let _consistency_lock = self.total_consistency_lock.write().unwrap();

		write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);

		self.genesis_hash.write(writer)?;
		{
			let best_block = self.best_block.read().unwrap();
			best_block.height().write(writer)?;
			best_block.block_hash().write(writer)?;
		}

		let channel_state = self.channel_state.lock().unwrap();
		let mut unfunded_channels = 0;
		for (_, channel) in channel_state.by_id.iter() {
			if !channel.is_funding_initiated() {
				unfunded_channels += 1;
			}
		}
		((channel_state.by_id.len() - unfunded_channels) as u64).write(writer)?;
		for (_, channel) in channel_state.by_id.iter() {
			if channel.is_funding_initiated() {
				channel.write(writer)?;
			}
		}

		(channel_state.forward_htlcs.len() as u64).write(writer)?;
		for (short_channel_id, pending_forwards) in channel_state.forward_htlcs.iter() {
			short_channel_id.write(writer)?;
			(pending_forwards.len() as u64).write(writer)?;
			for forward in pending_forwards {
				forward.write(writer)?;
			}
		}

		(channel_state.claimable_htlcs.len() as u64).write(writer)?;
		for (payment_hash, previous_hops) in channel_state.claimable_htlcs.iter() {
			payment_hash.write(writer)?;
			(previous_hops.len() as u64).write(writer)?;
			for htlc in previous_hops.iter() {
				htlc.write(writer)?;
			}
		}

		let per_peer_state = self.per_peer_state.write().unwrap();
		(per_peer_state.len() as u64).write(writer)?;
		for (peer_pubkey, peer_state_mutex) in per_peer_state.iter() {
			peer_pubkey.write(writer)?;
			let peer_state = peer_state_mutex.lock().unwrap();
			peer_state.latest_features.write(writer)?;
		}

		let events = self.pending_events.lock().unwrap();
		(events.len() as u64).write(writer)?;
		for event in events.iter() {
			event.write(writer)?;
		}

		let background_events = self.pending_background_events.lock().unwrap();
		(background_events.len() as u64).write(writer)?;
		for event in background_events.iter() {
			match event {
				BackgroundEvent::ClosingMonitorUpdate((funding_txo, monitor_update)) => {
					0u8.write(writer)?;
					funding_txo.write(writer)?;
					monitor_update.write(writer)?;
				},
			}
		}

		(self.last_node_announcement_serial.load(Ordering::Acquire) as u32).write(writer)?;
		(self.highest_seen_timestamp.load(Ordering::Acquire) as u32).write(writer)?;

		let pending_inbound_payments = self.pending_inbound_payments.lock().unwrap();
		(pending_inbound_payments.len() as u64).write(writer)?;
		for (hash, pending_payment) in pending_inbound_payments.iter() {
			hash.write(writer)?;
			pending_payment.write(writer)?;
		}

		let pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
		(pending_outbound_payments.len() as u64).write(writer)?;
		for session_priv in pending_outbound_payments.iter() {
			session_priv.write(writer)?;
		}

		write_tlv_fields!(writer, {});

		Ok(())
	}
}

/// Arguments for the creation of a ChannelManager that are not deserialized.
///
/// At a high-level, the process for deserializing a ChannelManager and resuming normal operation
/// is:
/// 1) Deserialize all stored ChannelMonitors.
/// 2) Deserialize the ChannelManager by filling in this struct and calling:
///    <(BlockHash, ChannelManager)>::read(reader, args)
///    This may result in closing some Channels if the ChannelMonitor is newer than the stored
///    ChannelManager state to ensure no loss of funds. Thus, transactions may be broadcasted.
/// 3) If you are not fetching full blocks, register all relevant ChannelMonitor outpoints the same
///    way you would handle a `chain::Filter` call using ChannelMonitor::get_outputs_to_watch() and
///    ChannelMonitor::get_funding_txo().
/// 4) Reconnect blocks on your ChannelMonitors.
/// 5) Disconnect/connect blocks on the ChannelManager.
/// 6) Move the ChannelMonitors into your local chain::Watch.
///
/// Note that the ordering of #4-6 is not of importance, however all three must occur before you
/// call any other methods on the newly-deserialized ChannelManager.
///
/// Note that because some channels may be closed during deserialization, it is critical that you
/// always deserialize only the latest version of a ChannelManager and ChannelMonitors available to
/// you. If you deserialize an old ChannelManager (during which force-closure transactions may be
/// broadcast), and then later deserialize a newer version of the same ChannelManager (which will
/// not force-close the same channels but consider them live), you may end up revoking a state for
/// which you've already broadcasted the transaction.
pub struct ChannelManagerReadArgs<'a, Signer: 'a + Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
	where M::Target: chain::Watch<Signer>,
        T::Target: BroadcasterInterface,
        K::Target: KeysInterface<Signer = Signer>,
        F::Target: FeeEstimator,
        L::Target: Logger,
{
	/// The keys provider which will give us relevant keys. Some keys will be loaded during
	/// deserialization and KeysInterface::read_chan_signer will be used to read per-Channel
	/// signing data.
	pub keys_manager: K,

	/// The fee_estimator for use in the ChannelManager in the future.
	///
	/// No calls to the FeeEstimator will be made during deserialization.
	pub fee_estimator: F,
	/// The chain::Watch for use in the ChannelManager in the future.
	///
	/// No calls to the chain::Watch will be made during deserialization. It is assumed that
	/// you have deserialized ChannelMonitors separately and will add them to your
	/// chain::Watch after deserializing this ChannelManager.
	pub chain_monitor: M,

	/// The BroadcasterInterface which will be used in the ChannelManager in the future and may be
	/// used to broadcast the latest local commitment transactions of channels which must be
	/// force-closed during deserialization.
	pub tx_broadcaster: T,
	/// The Logger for use in the ChannelManager and which may be used to log information during
	/// deserialization.
	pub logger: L,
	/// Default settings used for new channels. Any existing channels will continue to use the
	/// runtime settings which were stored when the ChannelManager was serialized.
	pub default_config: UserConfig,

	/// A map from channel funding outpoints to ChannelMonitors for those channels (ie
	/// value.get_funding_txo() should be the key).
	///
	/// If a monitor is inconsistent with the channel state during deserialization the channel will
	/// be force-closed using the data in the ChannelMonitor and the channel will be dropped. This
	/// is true for missing channels as well. If there is a monitor missing for which we find
	/// channel data Err(DecodeError::InvalidValue) will be returned.
	///
	/// In such cases the latest local transactions will be sent to the tx_broadcaster included in
	/// this struct.
	///
	/// (C-not exported) because we have no HashMap bindings
	pub channel_monitors: HashMap<OutPoint, &'a mut ChannelMonitor<Signer>>,
}

impl<'a, Signer: 'a + Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
		ChannelManagerReadArgs<'a, Signer, M, T, K, F, L>
	where M::Target: chain::Watch<Signer>,
		T::Target: BroadcasterInterface,
		K::Target: KeysInterface<Signer = Signer>,
		F::Target: FeeEstimator,
		L::Target: Logger,
	{
	/// Simple utility function to create a ChannelManagerReadArgs which creates the monitor
	/// HashMap for you. This is primarily useful for C bindings where it is not practical to
	/// populate a HashMap directly from C.
	pub fn new(keys_manager: K, fee_estimator: F, chain_monitor: M, tx_broadcaster: T, logger: L, default_config: UserConfig,
			mut channel_monitors: Vec<&'a mut ChannelMonitor<Signer>>) -> Self {
		Self {
			keys_manager, fee_estimator, chain_monitor, tx_broadcaster, logger, default_config,
			channel_monitors: channel_monitors.drain(..).map(|monitor| { (monitor.get_funding_txo().0, monitor) }).collect()
		}
	}
}

// Implement ReadableArgs for an Arc'd ChannelManager to make it a bit easier to work with the
// SipmleArcChannelManager type:
impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
	ReadableArgs<ChannelManagerReadArgs<'a, Signer, M, T, K, F, L>> for (BlockHash, Arc<ChannelManager<Signer, M, T, K, F, L>>)
	where M::Target: chain::Watch<Signer>,
        T::Target: BroadcasterInterface,
        K::Target: KeysInterface<Signer = Signer>,
        F::Target: FeeEstimator,
        L::Target: Logger,
{
	fn read<R: ::std::io::Read>(reader: &mut R, args: ChannelManagerReadArgs<'a, Signer, M, T, K, F, L>) -> Result<Self, DecodeError> {
		let (blockhash, chan_manager) = <(BlockHash, ChannelManager<Signer, M, T, K, F, L>)>::read(reader, args)?;
		Ok((blockhash, Arc::new(chan_manager)))
	}
}

impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
	ReadableArgs<ChannelManagerReadArgs<'a, Signer, M, T, K, F, L>> for (BlockHash, ChannelManager<Signer, M, T, K, F, L>)
	where M::Target: chain::Watch<Signer>,
        T::Target: BroadcasterInterface,
        K::Target: KeysInterface<Signer = Signer>,
        F::Target: FeeEstimator,
        L::Target: Logger,
{
	fn read<R: ::std::io::Read>(reader: &mut R, mut args: ChannelManagerReadArgs<'a, Signer, M, T, K, F, L>) -> Result<Self, DecodeError> {
		let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);

		let genesis_hash: BlockHash = Readable::read(reader)?;
		let best_block_height: u32 = Readable::read(reader)?;
		let best_block_hash: BlockHash = Readable::read(reader)?;

		let mut failed_htlcs = Vec::new();

		let channel_count: u64 = Readable::read(reader)?;
		let mut funding_txo_set = HashSet::with_capacity(cmp::min(channel_count as usize, 128));
		let mut by_id = HashMap::with_capacity(cmp::min(channel_count as usize, 128));
		let mut short_to_id = HashMap::with_capacity(cmp::min(channel_count as usize, 128));
		for _ in 0..channel_count {
			let mut channel: Channel<Signer> = Channel::read(reader, &args.keys_manager)?;
			let funding_txo = channel.get_funding_txo().ok_or(DecodeError::InvalidValue)?;
			funding_txo_set.insert(funding_txo.clone());
			if let Some(ref mut monitor) = args.channel_monitors.get_mut(&funding_txo) {
				if channel.get_cur_holder_commitment_transaction_number() < monitor.get_cur_holder_commitment_number() ||
						channel.get_revoked_counterparty_commitment_transaction_number() < monitor.get_min_seen_secret() ||
						channel.get_cur_counterparty_commitment_transaction_number() < monitor.get_cur_counterparty_commitment_number() ||
						channel.get_latest_monitor_update_id() > monitor.get_latest_update_id() {
					// If the channel is ahead of the monitor, return InvalidValue:
					log_error!(args.logger, "A ChannelMonitor is stale compared to the current ChannelManager! This indicates a potentially-critical violation of the chain::Watch API!");
					log_error!(args.logger, " The ChannelMonitor for channel {} is at update_id {} but the ChannelManager is at update_id {}.",
						log_bytes!(channel.channel_id()), monitor.get_latest_update_id(), channel.get_latest_monitor_update_id());
					log_error!(args.logger, " The chain::Watch API *requires* that monitors are persisted durably before returning,");
					log_error!(args.logger, " client applications must ensure that ChannelMonitor data is always available and the latest to avoid funds loss!");
					log_error!(args.logger, " Without the latest ChannelMonitor we cannot continue without risking funds.");
					log_error!(args.logger, " Please ensure the chain::Watch API requirements are met and file a bug report at https://github.com/rust-bitcoin/rust-lightning");
					return Err(DecodeError::InvalidValue);
				} else if channel.get_cur_holder_commitment_transaction_number() > monitor.get_cur_holder_commitment_number() ||
						channel.get_revoked_counterparty_commitment_transaction_number() > monitor.get_min_seen_secret() ||
						channel.get_cur_counterparty_commitment_transaction_number() > monitor.get_cur_counterparty_commitment_number() ||
						channel.get_latest_monitor_update_id() < monitor.get_latest_update_id() {
					// But if the channel is behind of the monitor, close the channel:
					let (_, mut new_failed_htlcs) = channel.force_shutdown(true);
					failed_htlcs.append(&mut new_failed_htlcs);
					monitor.broadcast_latest_holder_commitment_txn(&args.tx_broadcaster, &args.logger);
				} else {
					if let Some(short_channel_id) = channel.get_short_channel_id() {
						short_to_id.insert(short_channel_id, channel.channel_id());
					}
					by_id.insert(channel.channel_id(), channel);
				}
			} else {
				log_error!(args.logger, "Missing ChannelMonitor for channel {} needed by ChannelManager.", log_bytes!(channel.channel_id()));
				log_error!(args.logger, " The chain::Watch API *requires* that monitors are persisted durably before returning,");
				log_error!(args.logger, " client applications must ensure that ChannelMonitor data is always available and the latest to avoid funds loss!");
				log_error!(args.logger, " Without the ChannelMonitor we cannot continue without risking funds.");
				log_error!(args.logger, " Please ensure the chain::Watch API requirements are met and file a bug report at https://github.com/rust-bitcoin/rust-lightning");
				return Err(DecodeError::InvalidValue);
			}
		}

		for (ref funding_txo, ref mut monitor) in args.channel_monitors.iter_mut() {
			if !funding_txo_set.contains(funding_txo) {
				monitor.broadcast_latest_holder_commitment_txn(&args.tx_broadcaster, &args.logger);
			}
		}

		const MAX_ALLOC_SIZE: usize = 1024 * 64;
		let forward_htlcs_count: u64 = Readable::read(reader)?;
		let mut forward_htlcs = HashMap::with_capacity(cmp::min(forward_htlcs_count as usize, 128));
		for _ in 0..forward_htlcs_count {
			let short_channel_id = Readable::read(reader)?;
			let pending_forwards_count: u64 = Readable::read(reader)?;
			let mut pending_forwards = Vec::with_capacity(cmp::min(pending_forwards_count as usize, MAX_ALLOC_SIZE/mem::size_of::<HTLCForwardInfo>()));
			for _ in 0..pending_forwards_count {
				pending_forwards.push(Readable::read(reader)?);
			}
			forward_htlcs.insert(short_channel_id, pending_forwards);
		}

		let claimable_htlcs_count: u64 = Readable::read(reader)?;
		let mut claimable_htlcs = HashMap::with_capacity(cmp::min(claimable_htlcs_count as usize, 128));
		for _ in 0..claimable_htlcs_count {
			let payment_hash = Readable::read(reader)?;
			let previous_hops_len: u64 = Readable::read(reader)?;
			let mut previous_hops = Vec::with_capacity(cmp::min(previous_hops_len as usize, MAX_ALLOC_SIZE/mem::size_of::<ClaimableHTLC>()));
			for _ in 0..previous_hops_len {
				previous_hops.push(Readable::read(reader)?);
			}
			claimable_htlcs.insert(payment_hash, previous_hops);
		}

		let peer_count: u64 = Readable::read(reader)?;
		let mut per_peer_state = HashMap::with_capacity(cmp::min(peer_count as usize, MAX_ALLOC_SIZE/mem::size_of::<(PublicKey, Mutex<PeerState>)>()));
		for _ in 0..peer_count {
			let peer_pubkey = Readable::read(reader)?;
			let peer_state = PeerState {
				latest_features: Readable::read(reader)?,
			};
			per_peer_state.insert(peer_pubkey, Mutex::new(peer_state));
		}

		let event_count: u64 = Readable::read(reader)?;
		let mut pending_events_read: Vec<events::Event> = Vec::with_capacity(cmp::min(event_count as usize, MAX_ALLOC_SIZE/mem::size_of::<events::Event>()));
		for _ in 0..event_count {
			match MaybeReadable::read(reader)? {
				Some(event) => pending_events_read.push(event),
				None => continue,
			}
		}

		let background_event_count: u64 = Readable::read(reader)?;
		let mut pending_background_events_read: Vec<BackgroundEvent> = Vec::with_capacity(cmp::min(background_event_count as usize, MAX_ALLOC_SIZE/mem::size_of::<BackgroundEvent>()));
		for _ in 0..background_event_count {
			match <u8 as Readable>::read(reader)? {
				0 => pending_background_events_read.push(BackgroundEvent::ClosingMonitorUpdate((Readable::read(reader)?, Readable::read(reader)?))),
				_ => return Err(DecodeError::InvalidValue),
			}
		}

		let last_node_announcement_serial: u32 = Readable::read(reader)?;
		let highest_seen_timestamp: u32 = Readable::read(reader)?;

		let pending_inbound_payment_count: u64 = Readable::read(reader)?;
		let mut pending_inbound_payments: HashMap<PaymentHash, PendingInboundPayment> = HashMap::with_capacity(cmp::min(pending_inbound_payment_count as usize, MAX_ALLOC_SIZE/(3*32)));
		for _ in 0..pending_inbound_payment_count {
			if pending_inbound_payments.insert(Readable::read(reader)?, Readable::read(reader)?).is_some() {
				return Err(DecodeError::InvalidValue);
			}
		}

		let pending_outbound_payments_count: u64 = Readable::read(reader)?;
		let mut pending_outbound_payments: HashSet<[u8; 32]> = HashSet::with_capacity(cmp::min(pending_outbound_payments_count as usize, MAX_ALLOC_SIZE/32));
		for _ in 0..pending_outbound_payments_count {
			if !pending_outbound_payments.insert(Readable::read(reader)?) {
				return Err(DecodeError::InvalidValue);
			}
		}

		read_tlv_fields!(reader, {});

		let mut secp_ctx = Secp256k1::new();
		secp_ctx.seeded_randomize(&args.keys_manager.get_secure_random_bytes());

		let channel_manager = ChannelManager {
			genesis_hash,
			fee_estimator: args.fee_estimator,
			chain_monitor: args.chain_monitor,
			tx_broadcaster: args.tx_broadcaster,

			best_block: RwLock::new(BestBlock::new(best_block_hash, best_block_height)),

			channel_state: Mutex::new(ChannelHolder {
				by_id,
				short_to_id,
				forward_htlcs,
				claimable_htlcs,
				pending_msg_events: Vec::new(),
			}),
			pending_inbound_payments: Mutex::new(pending_inbound_payments),
			pending_outbound_payments: Mutex::new(pending_outbound_payments),

			our_network_key: args.keys_manager.get_node_secret(),
			our_network_pubkey: PublicKey::from_secret_key(&secp_ctx, &args.keys_manager.get_node_secret()),
			secp_ctx,

			last_node_announcement_serial: AtomicUsize::new(last_node_announcement_serial as usize),
			highest_seen_timestamp: AtomicUsize::new(highest_seen_timestamp as usize),

			per_peer_state: RwLock::new(per_peer_state),

			pending_events: Mutex::new(pending_events_read),
			pending_background_events: Mutex::new(pending_background_events_read),
			total_consistency_lock: RwLock::new(()),
			persistence_notifier: PersistenceNotifier::new(),

			keys_manager: args.keys_manager,
			logger: args.logger,
			default_configuration: args.default_config,
		};

		for htlc_source in failed_htlcs.drain(..) {
			channel_manager.fail_htlc_backwards_internal(channel_manager.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() });
		}

		//TODO: Broadcast channel update for closed channels, but only after we've made a
		//connection or two.

		Ok((best_block_hash.clone(), channel_manager))
	}
}

#[cfg(test)]
mod tests {
	use ln::channelmanager::PersistenceNotifier;
	use std::sync::Arc;
	use core::sync::atomic::{AtomicBool, Ordering};
	use std::thread;
	use core::time::Duration;
	use ln::functional_test_utils::*;
	use ln::features::InitFeatures;
	use ln::msgs::ChannelMessageHandler;

	#[test]
	fn test_wait_timeout() {
		let persistence_notifier = Arc::new(PersistenceNotifier::new());
		let thread_notifier = Arc::clone(&persistence_notifier);

		let exit_thread = Arc::new(AtomicBool::new(false));
		let exit_thread_clone = exit_thread.clone();
		thread::spawn(move || {
			loop {
				let &(ref persist_mtx, ref cnd) = &thread_notifier.persistence_lock;
				let mut persistence_lock = persist_mtx.lock().unwrap();
				*persistence_lock = true;
				cnd.notify_all();

				if exit_thread_clone.load(Ordering::SeqCst) {
					break
				}
			}
		});

		// Check that we can block indefinitely until updates are available.
		let _ = persistence_notifier.wait();

		// Check that the PersistenceNotifier will return after the given duration if updates are
		// available.
		loop {
			if persistence_notifier.wait_timeout(Duration::from_millis(100)) {
				break
			}
		}

		exit_thread.store(true, Ordering::SeqCst);

		// Check that the PersistenceNotifier will return after the given duration even if no updates
		// are available.
		loop {
			if !persistence_notifier.wait_timeout(Duration::from_millis(100)) {
				break
			}
		}
	}

	#[test]
	fn test_notify_limits() {
		// Check that a few cases which don't require the persistence of a new ChannelManager,
		// indeed, do not cause the persistence of a new ChannelManager.
		let chanmon_cfgs = create_chanmon_cfgs(3);
		let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
		let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
		let nodes = create_network(3, &node_cfgs, &node_chanmgrs);

		let mut chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());

		// We check that the channel info nodes have doesn't change too early, even though we try
		// to connect messages with new values
		chan.0.contents.fee_base_msat *= 2;
		chan.1.contents.fee_base_msat *= 2;
		let node_a_chan_info = nodes[0].node.list_channels()[0].clone();
		let node_b_chan_info = nodes[1].node.list_channels()[0].clone();

		// The first two nodes (which opened a channel) should now require fresh persistence
		assert!(nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
		assert!(nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
		// ... but the last node should not.
		assert!(!nodes[2].node.await_persistable_update_timeout(Duration::from_millis(1)));
		// After persisting the first two nodes they should no longer need fresh persistence.
		assert!(!nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
		assert!(!nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));

		// Node 3, unrelated to the only channel, shouldn't care if it receives a channel_update
		// about the channel.
		nodes[2].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &chan.0);
		nodes[2].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &chan.1);
		assert!(!nodes[2].node.await_persistable_update_timeout(Duration::from_millis(1)));

		// The nodes which are a party to the channel should also ignore messages from unrelated
		// parties.
		nodes[0].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.0);
		nodes[0].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.1);
		nodes[1].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.0);
		nodes[1].node.handle_channel_update(&nodes[2].node.get_our_node_id(), &chan.1);
		assert!(!nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
		assert!(!nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));

		// At this point the channel info given by peers should still be the same.
		assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
		assert_eq!(nodes[1].node.list_channels()[0], node_b_chan_info);

		// An earlier version of handle_channel_update didn't check the directionality of the
		// update message and would always update the local fee info, even if our peer was
		// (spuriously) forwarding us our own channel_update.
		let as_node_one = nodes[0].node.get_our_node_id().serialize()[..] < nodes[1].node.get_our_node_id().serialize()[..];
		let as_update = if as_node_one == (chan.0.contents.flags & 1 == 0 /* chan.0 is from node one */) { &chan.0 } else { &chan.1 };
		let bs_update = if as_node_one == (chan.0.contents.flags & 1 == 0 /* chan.0 is from node one */) { &chan.1 } else { &chan.0 };

		// First deliver each peers' own message, checking that the node doesn't need to be
		// persisted and that its channel info remains the same.
		nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &as_update);
		nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &bs_update);
		assert!(!nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
		assert!(!nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
		assert_eq!(nodes[0].node.list_channels()[0], node_a_chan_info);
		assert_eq!(nodes[1].node.list_channels()[0], node_b_chan_info);

		// Finally, deliver the other peers' message, ensuring each node needs to be persisted and
		// the channel info has updated.
		nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &bs_update);
		nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &as_update);
		assert!(nodes[0].node.await_persistable_update_timeout(Duration::from_millis(1)));
		assert!(nodes[1].node.await_persistable_update_timeout(Duration::from_millis(1)));
		assert_ne!(nodes[0].node.list_channels()[0], node_a_chan_info);
		assert_ne!(nodes[1].node.list_channels()[0], node_b_chan_info);
	}
}

#[cfg(all(any(test, feature = "_test_utils"), feature = "unstable"))]
pub mod bench {
	use chain::Listen;
	use chain::chainmonitor::ChainMonitor;
	use chain::channelmonitor::Persist;
	use chain::keysinterface::{KeysManager, InMemorySigner};
	use ln::channelmanager::{BestBlock, ChainParameters, ChannelManager, PaymentHash, PaymentPreimage};
	use ln::features::{InitFeatures, InvoiceFeatures};
	use ln::functional_test_utils::*;
	use ln::msgs::ChannelMessageHandler;
	use routing::network_graph::NetworkGraph;
	use routing::router::get_route;
	use util::test_utils;
	use util::config::UserConfig;
	use util::events::{Event, MessageSendEvent, MessageSendEventsProvider};

	use bitcoin::hashes::Hash;
	use bitcoin::hashes::sha256::Hash as Sha256;
	use bitcoin::{Block, BlockHeader, Transaction, TxOut};

	use std::sync::{Arc, Mutex};

	use test::Bencher;

	struct NodeHolder<'a, P: Persist<InMemorySigner>> {
		node: &'a ChannelManager<InMemorySigner,
			&'a ChainMonitor<InMemorySigner, &'a test_utils::TestChainSource,
				&'a test_utils::TestBroadcaster, &'a test_utils::TestFeeEstimator,
				&'a test_utils::TestLogger, &'a P>,
			&'a test_utils::TestBroadcaster, &'a KeysManager,
			&'a test_utils::TestFeeEstimator, &'a test_utils::TestLogger>
	}

	#[cfg(test)]
	#[bench]
	fn bench_sends(bench: &mut Bencher) {
		bench_two_sends(bench, test_utils::TestPersister::new(), test_utils::TestPersister::new());
	}

	pub fn bench_two_sends<P: Persist<InMemorySigner>>(bench: &mut Bencher, persister_a: P, persister_b: P) {
		// Do a simple benchmark of sending a payment back and forth between two nodes.
		// Note that this is unrealistic as each payment send will require at least two fsync
		// calls per node.
		let network = bitcoin::Network::Testnet;
		let genesis_hash = bitcoin::blockdata::constants::genesis_block(network).header.block_hash();

		let tx_broadcaster = test_utils::TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))};
		let fee_estimator = test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) };

		let mut config: UserConfig = Default::default();
		config.own_channel_config.minimum_depth = 1;

		let logger_a = test_utils::TestLogger::with_id("node a".to_owned());
		let chain_monitor_a = ChainMonitor::new(None, &tx_broadcaster, &logger_a, &fee_estimator, &persister_a);
		let seed_a = [1u8; 32];
		let keys_manager_a = KeysManager::new(&seed_a, 42, 42);
		let node_a = ChannelManager::new(&fee_estimator, &chain_monitor_a, &tx_broadcaster, &logger_a, &keys_manager_a, config.clone(), ChainParameters {
			network,
			best_block: BestBlock::from_genesis(network),
		});
		let node_a_holder = NodeHolder { node: &node_a };

		let logger_b = test_utils::TestLogger::with_id("node a".to_owned());
		let chain_monitor_b = ChainMonitor::new(None, &tx_broadcaster, &logger_a, &fee_estimator, &persister_b);
		let seed_b = [2u8; 32];
		let keys_manager_b = KeysManager::new(&seed_b, 42, 42);
		let node_b = ChannelManager::new(&fee_estimator, &chain_monitor_b, &tx_broadcaster, &logger_b, &keys_manager_b, config.clone(), ChainParameters {
			network,
			best_block: BestBlock::from_genesis(network),
		});
		let node_b_holder = NodeHolder { node: &node_b };

		node_a.create_channel(node_b.get_our_node_id(), 8_000_000, 100_000_000, 42, None).unwrap();
		node_b.handle_open_channel(&node_a.get_our_node_id(), InitFeatures::known(), &get_event_msg!(node_a_holder, MessageSendEvent::SendOpenChannel, node_b.get_our_node_id()));
		node_a.handle_accept_channel(&node_b.get_our_node_id(), InitFeatures::known(), &get_event_msg!(node_b_holder, MessageSendEvent::SendAcceptChannel, node_a.get_our_node_id()));

		let tx;
		if let Event::FundingGenerationReady { temporary_channel_id, output_script, .. } = get_event!(node_a_holder, Event::FundingGenerationReady) {
			tx = Transaction { version: 2, lock_time: 0, input: Vec::new(), output: vec![TxOut {
				value: 8_000_000, script_pubkey: output_script,
			}]};
			node_a.funding_transaction_generated(&temporary_channel_id, tx.clone()).unwrap();
		} else { panic!(); }

		node_b.handle_funding_created(&node_a.get_our_node_id(), &get_event_msg!(node_a_holder, MessageSendEvent::SendFundingCreated, node_b.get_our_node_id()));
		node_a.handle_funding_signed(&node_b.get_our_node_id(), &get_event_msg!(node_b_holder, MessageSendEvent::SendFundingSigned, node_a.get_our_node_id()));

		assert_eq!(&tx_broadcaster.txn_broadcasted.lock().unwrap()[..], &[tx.clone()]);

		let block = Block {
			header: BlockHeader { version: 0x20000000, prev_blockhash: genesis_hash, merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 },
			txdata: vec![tx],
		};
		Listen::block_connected(&node_a, &block, 1);
		Listen::block_connected(&node_b, &block, 1);

		node_a.handle_funding_locked(&node_b.get_our_node_id(), &get_event_msg!(node_b_holder, MessageSendEvent::SendFundingLocked, node_a.get_our_node_id()));
		let msg_events = node_a.get_and_clear_pending_msg_events();
		assert_eq!(msg_events.len(), 2);
		match msg_events[0] {
			MessageSendEvent::SendFundingLocked { ref msg, .. } => {
				node_b.handle_funding_locked(&node_a.get_our_node_id(), msg);
				get_event_msg!(node_b_holder, MessageSendEvent::SendChannelUpdate, node_a.get_our_node_id());
			},
			_ => panic!(),
		}
		match msg_events[1] {
			MessageSendEvent::SendChannelUpdate { .. } => {},
			_ => panic!(),
		}

		let dummy_graph = NetworkGraph::new(genesis_hash);

		let mut payment_count: u64 = 0;
		macro_rules! send_payment {
			($node_a: expr, $node_b: expr) => {
				let usable_channels = $node_a.list_usable_channels();
				let route = get_route(&$node_a.get_our_node_id(), &dummy_graph, &$node_b.get_our_node_id(), Some(InvoiceFeatures::known()),
					Some(&usable_channels.iter().map(|r| r).collect::<Vec<_>>()), &[], 10_000, TEST_FINAL_CLTV, &logger_a).unwrap();

				let mut payment_preimage = PaymentPreimage([0; 32]);
				payment_preimage.0[0..8].copy_from_slice(&payment_count.to_le_bytes());
				payment_count += 1;
				let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner());
				let payment_secret = $node_b.create_inbound_payment_for_hash(payment_hash, None, 7200, 0).unwrap();

				$node_a.send_payment(&route, payment_hash, &Some(payment_secret)).unwrap();
				let payment_event = SendEvent::from_event($node_a.get_and_clear_pending_msg_events().pop().unwrap());
				$node_b.handle_update_add_htlc(&$node_a.get_our_node_id(), &payment_event.msgs[0]);
				$node_b.handle_commitment_signed(&$node_a.get_our_node_id(), &payment_event.commitment_msg);
				let (raa, cs) = get_revoke_commit_msgs!(NodeHolder { node: &$node_b }, $node_a.get_our_node_id());
				$node_a.handle_revoke_and_ack(&$node_b.get_our_node_id(), &raa);
				$node_a.handle_commitment_signed(&$node_b.get_our_node_id(), &cs);
				$node_b.handle_revoke_and_ack(&$node_a.get_our_node_id(), &get_event_msg!(NodeHolder { node: &$node_a }, MessageSendEvent::SendRevokeAndACK, $node_b.get_our_node_id()));

				expect_pending_htlcs_forwardable!(NodeHolder { node: &$node_b });
				expect_payment_received!(NodeHolder { node: &$node_b }, payment_hash, payment_secret, 10_000);
				assert!($node_b.claim_funds(payment_preimage));

				match $node_b.get_and_clear_pending_msg_events().pop().unwrap() {
					MessageSendEvent::UpdateHTLCs { node_id, updates } => {
						assert_eq!(node_id, $node_a.get_our_node_id());
						$node_a.handle_update_fulfill_htlc(&$node_b.get_our_node_id(), &updates.update_fulfill_htlcs[0]);
						$node_a.handle_commitment_signed(&$node_b.get_our_node_id(), &updates.commitment_signed);
					},
					_ => panic!("Failed to generate claim event"),
				}

				let (raa, cs) = get_revoke_commit_msgs!(NodeHolder { node: &$node_a }, $node_b.get_our_node_id());
				$node_b.handle_revoke_and_ack(&$node_a.get_our_node_id(), &raa);
				$node_b.handle_commitment_signed(&$node_a.get_our_node_id(), &cs);
				$node_a.handle_revoke_and_ack(&$node_b.get_our_node_id(), &get_event_msg!(NodeHolder { node: &$node_b }, MessageSendEvent::SendRevokeAndACK, $node_a.get_our_node_id()));

				expect_payment_sent!(NodeHolder { node: &$node_a }, payment_preimage);
			}
		}

		bench.iter(|| {
			send_payment!(node_a, node_b);
			send_payment!(node_b, node_a);
		});
	}
}