]> git.bitcoin.ninja Git - rust-lightning/commitdiff
Rename background-processor to lightning-... to match other crates 2021-04-bp-bindings
authorMatt Corallo <git@bluematt.me>
Tue, 13 Apr 2021 23:39:32 +0000 (19:39 -0400)
committerMatt Corallo <git@bluematt.me>
Thu, 15 Apr 2021 19:23:05 +0000 (15:23 -0400)
Cargo.toml
background-processor/Cargo.toml [deleted file]
background-processor/src/lib.rs [deleted file]
lightning-background-processor/Cargo.toml [new file with mode: 0644]
lightning-background-processor/src/lib.rs [new file with mode: 0644]

index e1807eab684e29e4a7bc6f0dd7839281379dfb65..597d4efbabb4e8cca00458db04ddfa2b3bb29c9c 100644 (file)
@@ -6,7 +6,7 @@ members = [
     "lightning-invoice",
     "lightning-net-tokio",
     "lightning-persister",
-    "background-processor",
+    "lightning-background-processor",
 ]
 
 # Our tests do actual crypo and lots of work, the tradeoff for -O1 is well worth it.
diff --git a/background-processor/Cargo.toml b/background-processor/Cargo.toml
deleted file mode 100644 (file)
index 89ac216..0000000
+++ /dev/null
@@ -1,22 +0,0 @@
-[package]
-name = "lightning-background-processor"
-version = "0.0.13"
-authors = ["Valentine Wallace <vwallace@protonmail.com>"]
-license = "MIT OR Apache-2.0"
-repository = "http://github.com/rust-bitcoin/rust-lightning"
-description = """
-Utilities to perform required background tasks for Rust Lightning.
-"""
-edition = "2018"
-
-[dependencies]
-bitcoin = "0.26"
-lightning = { version = "0.0.13", path = "../lightning", features = ["allow_wallclock_use"] }
-lightning-persister = { version = "0.0.13", path = "../lightning-persister" }
-
-[dev-dependencies]
-lightning = { version = "0.0.13", path = "../lightning", features = ["_test_utils"] }
-
-[dev-dependencies.bitcoin]
-version = "0.26"
-features = ["bitcoinconsensus"]
diff --git a/background-processor/src/lib.rs b/background-processor/src/lib.rs
deleted file mode 100644 (file)
index de9aa28..0000000
+++ /dev/null
@@ -1,372 +0,0 @@
-//! Utilities that take care of tasks that (1) need to happen periodically to keep Rust-Lightning
-//! running properly, and (2) either can or should be run in the background. See docs for
-//! [`BackgroundProcessor`] for more details on the nitty-gritty.
-
-#![deny(broken_intra_doc_links)]
-#![deny(missing_docs)]
-#![deny(unsafe_code)]
-
-#[macro_use] extern crate lightning;
-
-use lightning::chain;
-use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
-use lightning::chain::keysinterface::{Sign, KeysInterface};
-use lightning::ln::channelmanager::ChannelManager;
-use lightning::ln::msgs::{ChannelMessageHandler, RoutingMessageHandler};
-use lightning::ln::peer_handler::{PeerManager, SocketDescriptor};
-use lightning::util::logger::Logger;
-use std::sync::Arc;
-use std::sync::atomic::{AtomicBool, Ordering};
-use std::thread;
-use std::thread::JoinHandle;
-use std::time::{Duration, Instant};
-use std::ops::Deref;
-
-/// BackgroundProcessor takes care of tasks that (1) need to happen periodically to keep
-/// Rust-Lightning running properly, and (2) either can or should be run in the background. Its
-/// responsibilities are:
-/// * Monitoring whether the ChannelManager needs to be re-persisted to disk, and if so,
-///   writing it to disk/backups by invoking the callback given to it at startup.
-///   ChannelManager persistence should be done in the background.
-/// * Calling `ChannelManager::timer_tick_occurred()` and
-///   `PeerManager::timer_tick_occurred()` every minute (can be done in the
-///   background).
-///
-/// Note that if ChannelManager persistence fails and the persisted manager becomes out-of-date,
-/// then there is a risk of channels force-closing on startup when the manager realizes it's
-/// outdated. However, as long as `ChannelMonitor` backups are sound, no funds besides those used
-/// for unilateral chain closure fees are at risk.
-pub struct BackgroundProcessor {
-       stop_thread: Arc<AtomicBool>,
-       /// May be used to retrieve and handle the error if `BackgroundProcessor`'s thread
-       /// exits due to an error while persisting.
-       pub thread_handle: JoinHandle<Result<(), std::io::Error>>,
-}
-
-#[cfg(not(test))]
-const FRESHNESS_TIMER: u64 = 60;
-#[cfg(test)]
-const FRESHNESS_TIMER: u64 = 1;
-
-/// Trait which handles persisting a [`ChannelManager`] to disk.
-///
-/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
-pub trait ChannelManagerPersister<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
-where
-       M::Target: 'static + chain::Watch<Signer>,
-       T::Target: 'static + BroadcasterInterface,
-       K::Target: 'static + KeysInterface<Signer = Signer>,
-       F::Target: 'static + FeeEstimator,
-       L::Target: 'static + Logger,
-{
-       /// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed
-       /// (which will cause the [`BackgroundProcessor`] which called this method to exit.
-       ///
-       /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
-       fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>;
-}
-
-impl<Fun, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
-ChannelManagerPersister<Signer, M, T, K, F, L> for Fun where
-       M::Target: 'static + chain::Watch<Signer>,
-       T::Target: 'static + BroadcasterInterface,
-       K::Target: 'static + KeysInterface<Signer = Signer>,
-       F::Target: 'static + FeeEstimator,
-       L::Target: 'static + Logger,
-       Fun: Fn(&ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>,
-{
-       fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error> {
-               self(channel_manager)
-       }
-}
-
-impl BackgroundProcessor {
-       /// Start a background thread that takes care of responsibilities enumerated in the top-level
-       /// documentation.
-       ///
-       /// If `persist_manager` returns an error, then this thread will return said error (and
-       /// `start()` will need to be called again to restart the `BackgroundProcessor`). Users should
-       /// wait on [`thread_handle`]'s `join()` method to be able to tell if and when an error is
-       /// returned, or implement `persist_manager` such that an error is never returned to the
-       /// `BackgroundProcessor`
-       ///
-       /// `persist_manager` is responsible for writing out the [`ChannelManager`] to disk, and/or
-       /// uploading to one or more backup services. See [`ChannelManager::write`] for writing out a
-       /// [`ChannelManager`]. See [`FilesystemPersister::persist_manager`] for Rust-Lightning's
-       /// provided implementation.
-       ///
-       /// [`thread_handle`]: BackgroundProcessor::thread_handle
-       /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
-       /// [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
-       /// [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
-       pub fn start<
-               Signer: 'static + Sign,
-               M: 'static + Deref + Send + Sync,
-               T: 'static + Deref + Send + Sync,
-               K: 'static + Deref + Send + Sync,
-               F: 'static + Deref + Send + Sync,
-               L: 'static + Deref + Send + Sync,
-               Descriptor: 'static + SocketDescriptor + Send + Sync,
-               CMH: 'static + Deref + Send + Sync,
-               RMH: 'static + Deref + Send + Sync,
-               CMP: 'static + Send + ChannelManagerPersister<Signer, M, T, K, F, L>,
-               CM: 'static + Deref<Target = ChannelManager<Signer, M, T, K, F, L>> + Send + Sync,
-               PM: 'static + Deref<Target = PeerManager<Descriptor, CMH, RMH, L>> + Send + Sync,
-       >
-       (handler: CMP, channel_manager: CM, peer_manager: PM, logger: L) -> Self
-       where
-               M::Target: 'static + chain::Watch<Signer>,
-               T::Target: 'static + BroadcasterInterface,
-               K::Target: 'static + KeysInterface<Signer = Signer>,
-               F::Target: 'static + FeeEstimator,
-               L::Target: 'static + Logger,
-               CMH::Target: 'static + ChannelMessageHandler,
-               RMH::Target: 'static + RoutingMessageHandler,
-       {
-               let stop_thread = Arc::new(AtomicBool::new(false));
-               let stop_thread_clone = stop_thread.clone();
-               let handle = thread::spawn(move || -> Result<(), std::io::Error> {
-                       let mut current_time = Instant::now();
-                       loop {
-                               peer_manager.process_events();
-                               let updates_available =
-                                       channel_manager.await_persistable_update_timeout(Duration::from_millis(100));
-                               if updates_available {
-                                       handler.persist_manager(&*channel_manager)?;
-                               }
-                               // Exit the loop if the background processor was requested to stop.
-                               if stop_thread.load(Ordering::Acquire) == true {
-                                       log_trace!(logger, "Terminating background processor.");
-                                       return Ok(());
-                               }
-                               if current_time.elapsed().as_secs() > FRESHNESS_TIMER {
-                                       log_trace!(logger, "Calling ChannelManager's and PeerManager's timer_tick_occurred");
-                                       channel_manager.timer_tick_occurred();
-                                       peer_manager.timer_tick_occurred();
-                                       current_time = Instant::now();
-                               }
-                       }
-               });
-               Self { stop_thread: stop_thread_clone, thread_handle: handle }
-       }
-
-       /// Stop `BackgroundProcessor`'s thread.
-       pub fn stop(self) -> Result<(), std::io::Error> {
-               self.stop_thread.store(true, Ordering::Release);
-               self.thread_handle.join().unwrap()
-       }
-}
-
-#[cfg(test)]
-mod tests {
-       use bitcoin::blockdata::constants::genesis_block;
-       use bitcoin::blockdata::transaction::{Transaction, TxOut};
-       use bitcoin::network::constants::Network;
-       use lightning::chain;
-       use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
-       use lightning::chain::chainmonitor;
-       use lightning::chain::keysinterface::{Sign, InMemorySigner, KeysInterface, KeysManager};
-       use lightning::chain::transaction::OutPoint;
-       use lightning::get_event_msg;
-       use lightning::ln::channelmanager::{BestBlock, ChainParameters, ChannelManager, SimpleArcChannelManager};
-       use lightning::ln::features::InitFeatures;
-       use lightning::ln::msgs::ChannelMessageHandler;
-       use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor};
-       use lightning::util::config::UserConfig;
-       use lightning::util::events::{Event, EventsProvider, MessageSendEventsProvider, MessageSendEvent};
-       use lightning::util::logger::Logger;
-       use lightning::util::ser::Writeable;
-       use lightning::util::test_utils;
-       use lightning_persister::FilesystemPersister;
-       use std::fs;
-       use std::path::PathBuf;
-       use std::sync::{Arc, Mutex};
-       use std::time::Duration;
-       use super::BackgroundProcessor;
-
-       #[derive(Clone, Eq, Hash, PartialEq)]
-       struct TestDescriptor{}
-       impl SocketDescriptor for TestDescriptor {
-               fn send_data(&mut self, _data: &[u8], _resume_read: bool) -> usize {
-                       0
-               }
-
-               fn disconnect_socket(&mut self) {}
-       }
-
-       type ChainMonitor = chainmonitor::ChainMonitor<InMemorySigner, Arc<test_utils::TestChainSource>, Arc<test_utils::TestBroadcaster>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>, Arc<FilesystemPersister>>;
-
-       struct Node {
-               node: Arc<SimpleArcChannelManager<ChainMonitor, test_utils::TestBroadcaster, test_utils::TestFeeEstimator, test_utils::TestLogger>>,
-               peer_manager: Arc<PeerManager<TestDescriptor, Arc<test_utils::TestChannelMessageHandler>, Arc<test_utils::TestRoutingMessageHandler>, Arc<test_utils::TestLogger>>>,
-               persister: Arc<FilesystemPersister>,
-               logger: Arc<test_utils::TestLogger>,
-       }
-
-       impl Drop for Node {
-               fn drop(&mut self) {
-                       let data_dir = self.persister.get_data_dir();
-                       match fs::remove_dir_all(data_dir.clone()) {
-                               Err(e) => println!("Failed to remove test persister directory {}: {}", data_dir, e),
-                               _ => {}
-                       }
-               }
-       }
-
-       fn get_full_filepath(filepath: String, filename: String) -> String {
-               let mut path = PathBuf::from(filepath);
-               path.push(filename);
-               path.to_str().unwrap().to_string()
-       }
-
-       fn create_nodes(num_nodes: usize, persist_dir: String) -> Vec<Node> {
-               let mut nodes = Vec::new();
-               for i in 0..num_nodes {
-                       let tx_broadcaster = Arc::new(test_utils::TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())});
-                       let fee_estimator = Arc::new(test_utils::TestFeeEstimator { sat_per_kw: 253 });
-                       let chain_source = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
-                       let logger = Arc::new(test_utils::TestLogger::with_id(format!("node {}", i)));
-                       let persister = Arc::new(FilesystemPersister::new(format!("{}_persister_{}", persist_dir, i)));
-                       let seed = [i as u8; 32];
-                       let network = Network::Testnet;
-                       let now = Duration::from_secs(genesis_block(network).header.time as u64);
-                       let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_nanos()));
-                       let chain_monitor = Arc::new(chainmonitor::ChainMonitor::new(Some(chain_source.clone()), tx_broadcaster.clone(), logger.clone(), fee_estimator.clone(), persister.clone()));
-                       let params = ChainParameters {
-                               network,
-                               best_block: BestBlock::from_genesis(network),
-                       };
-                       let manager = Arc::new(ChannelManager::new(fee_estimator.clone(), chain_monitor.clone(), tx_broadcaster, logger.clone(), keys_manager.clone(), UserConfig::default(), params));
-                       let msg_handler = MessageHandler { chan_handler: Arc::new(test_utils::TestChannelMessageHandler::new()), route_handler: Arc::new(test_utils::TestRoutingMessageHandler::new() )};
-                       let peer_manager = Arc::new(PeerManager::new(msg_handler, keys_manager.get_node_secret(), &seed, logger.clone()));
-                       let node = Node { node: manager, peer_manager, persister, logger };
-                       nodes.push(node);
-               }
-               nodes
-       }
-
-       macro_rules! open_channel {
-               ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
-                       $node_a.node.create_channel($node_b.node.get_our_node_id(), $channel_value, 100, 42, None).unwrap();
-                       $node_b.node.handle_open_channel(&$node_a.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_a, MessageSendEvent::SendOpenChannel, $node_b.node.get_our_node_id()));
-                       $node_a.node.handle_accept_channel(&$node_b.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_b, MessageSendEvent::SendAcceptChannel, $node_a.node.get_our_node_id()));
-                       let events = $node_a.node.get_and_clear_pending_events();
-                       assert_eq!(events.len(), 1);
-                       let (temporary_channel_id, tx) = match events[0] {
-                               Event::FundingGenerationReady { ref temporary_channel_id, ref channel_value_satoshis, ref output_script, user_channel_id } => {
-                                       assert_eq!(*channel_value_satoshis, $channel_value);
-                                       assert_eq!(user_channel_id, 42);
-
-                                       let tx = Transaction { version: 1 as i32, lock_time: 0, input: Vec::new(), output: vec![TxOut {
-                                               value: *channel_value_satoshis, script_pubkey: output_script.clone(),
-                                       }]};
-                                       (*temporary_channel_id, tx)
-                               },
-                               _ => panic!("Unexpected event"),
-                       };
-
-                       $node_a.node.funding_transaction_generated(&temporary_channel_id, tx.clone()).unwrap();
-                       $node_b.node.handle_funding_created(&$node_a.node.get_our_node_id(), &get_event_msg!($node_a, MessageSendEvent::SendFundingCreated, $node_b.node.get_our_node_id()));
-                       $node_a.node.handle_funding_signed(&$node_b.node.get_our_node_id(), &get_event_msg!($node_b, MessageSendEvent::SendFundingSigned, $node_a.node.get_our_node_id()));
-                       tx
-               }}
-       }
-
-       #[test]
-       fn test_background_processor() {
-               // Test that when a new channel is created, the ChannelManager needs to be re-persisted with
-               // updates. Also test that when new updates are available, the manager signals that it needs
-               // re-persistence and is successfully re-persisted.
-               let nodes = create_nodes(2, "test_background_processor".to_string());
-
-               // Initiate the background processors to watch each node.
-               let data_dir = nodes[0].persister.get_data_dir();
-               let callback = move |node: &ChannelManager<InMemorySigner, Arc<ChainMonitor>, Arc<test_utils::TestBroadcaster>, Arc<KeysManager>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>>| FilesystemPersister::persist_manager(data_dir.clone(), node);
-               let bg_processor = BackgroundProcessor::start(callback, nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
-
-               // Go through the channel creation process until each node should have something persisted.
-               let tx = open_channel!(nodes[0], nodes[1], 100000);
-
-               macro_rules! check_persisted_data {
-                       ($node: expr, $filepath: expr, $expected_bytes: expr) => {
-                               match $node.write(&mut $expected_bytes) {
-                                       Ok(()) => {
-                                               loop {
-                                                       match std::fs::read($filepath) {
-                                                               Ok(bytes) => {
-                                                                       if bytes == $expected_bytes {
-                                                                               break
-                                                                       } else {
-                                                                               continue
-                                                                       }
-                                                               },
-                                                               Err(_) => continue
-                                                       }
-                                               }
-                                       },
-                                       Err(e) => panic!("Unexpected error: {}", e)
-                               }
-                       }
-               }
-
-               // Check that the initial channel manager data is persisted as expected.
-               let filepath = get_full_filepath("test_background_processor_persister_0".to_string(), "manager".to_string());
-               let mut expected_bytes = Vec::new();
-               check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
-               loop {
-                       if !nodes[0].node.get_persistence_condvar_value() { break }
-               }
-
-               // Force-close the channel.
-               nodes[0].node.force_close_channel(&OutPoint { txid: tx.txid(), index: 0 }.to_channel_id()).unwrap();
-
-               // Check that the force-close updates are persisted.
-               let mut expected_bytes = Vec::new();
-               check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
-               loop {
-                       if !nodes[0].node.get_persistence_condvar_value() { break }
-               }
-
-               assert!(bg_processor.stop().is_ok());
-       }
-
-       #[test]
-       fn test_timer_tick_called() {
-               // Test that ChannelManager's and PeerManager's `timer_tick_occurred` is called every
-               // `FRESHNESS_TIMER`.
-               let nodes = create_nodes(1, "test_timer_tick_called".to_string());
-               let data_dir = nodes[0].persister.get_data_dir();
-               let callback = move |node: &ChannelManager<InMemorySigner, Arc<ChainMonitor>, Arc<test_utils::TestBroadcaster>, Arc<KeysManager>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>>| FilesystemPersister::persist_manager(data_dir.clone(), node);
-               let bg_processor = BackgroundProcessor::start(callback, nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
-               loop {
-                       let log_entries = nodes[0].logger.lines.lock().unwrap();
-                       let desired_log = "Calling ChannelManager's and PeerManager's timer_tick_occurred".to_string();
-                       if log_entries.get(&("lightning_background_processor".to_string(), desired_log)).is_some() {
-                               break
-                       }
-               }
-
-               assert!(bg_processor.stop().is_ok());
-       }
-
-       #[test]
-       fn test_persist_error() {
-               // Test that if we encounter an error during manager persistence, the thread panics.
-               fn persist_manager<Signer, M, T, K, F, L>(_data: &ChannelManager<Signer, Arc<M>, Arc<T>, Arc<K>, Arc<F>, Arc<L>>) -> Result<(), std::io::Error>
-               where Signer: 'static + Sign,
-                     M: 'static + chain::Watch<Signer>,
-                     T: 'static + BroadcasterInterface,
-                     K: 'static + KeysInterface<Signer=Signer>,
-                     F: 'static + FeeEstimator,
-                     L: 'static + Logger,
-               {
-                       Err(std::io::Error::new(std::io::ErrorKind::Other, "test"))
-               }
-
-               let nodes = create_nodes(2, "test_persist_error".to_string());
-               let bg_processor = BackgroundProcessor::start(persist_manager, nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
-               open_channel!(nodes[0], nodes[1], 100000);
-
-               let _ = bg_processor.thread_handle.join().unwrap().expect_err("Errored persisting manager: test");
-       }
-}
diff --git a/lightning-background-processor/Cargo.toml b/lightning-background-processor/Cargo.toml
new file mode 100644 (file)
index 0000000..89ac216
--- /dev/null
@@ -0,0 +1,22 @@
+[package]
+name = "lightning-background-processor"
+version = "0.0.13"
+authors = ["Valentine Wallace <vwallace@protonmail.com>"]
+license = "MIT OR Apache-2.0"
+repository = "http://github.com/rust-bitcoin/rust-lightning"
+description = """
+Utilities to perform required background tasks for Rust Lightning.
+"""
+edition = "2018"
+
+[dependencies]
+bitcoin = "0.26"
+lightning = { version = "0.0.13", path = "../lightning", features = ["allow_wallclock_use"] }
+lightning-persister = { version = "0.0.13", path = "../lightning-persister" }
+
+[dev-dependencies]
+lightning = { version = "0.0.13", path = "../lightning", features = ["_test_utils"] }
+
+[dev-dependencies.bitcoin]
+version = "0.26"
+features = ["bitcoinconsensus"]
diff --git a/lightning-background-processor/src/lib.rs b/lightning-background-processor/src/lib.rs
new file mode 100644 (file)
index 0000000..de9aa28
--- /dev/null
@@ -0,0 +1,372 @@
+//! Utilities that take care of tasks that (1) need to happen periodically to keep Rust-Lightning
+//! running properly, and (2) either can or should be run in the background. See docs for
+//! [`BackgroundProcessor`] for more details on the nitty-gritty.
+
+#![deny(broken_intra_doc_links)]
+#![deny(missing_docs)]
+#![deny(unsafe_code)]
+
+#[macro_use] extern crate lightning;
+
+use lightning::chain;
+use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
+use lightning::chain::keysinterface::{Sign, KeysInterface};
+use lightning::ln::channelmanager::ChannelManager;
+use lightning::ln::msgs::{ChannelMessageHandler, RoutingMessageHandler};
+use lightning::ln::peer_handler::{PeerManager, SocketDescriptor};
+use lightning::util::logger::Logger;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::thread;
+use std::thread::JoinHandle;
+use std::time::{Duration, Instant};
+use std::ops::Deref;
+
+/// BackgroundProcessor takes care of tasks that (1) need to happen periodically to keep
+/// Rust-Lightning running properly, and (2) either can or should be run in the background. Its
+/// responsibilities are:
+/// * Monitoring whether the ChannelManager needs to be re-persisted to disk, and if so,
+///   writing it to disk/backups by invoking the callback given to it at startup.
+///   ChannelManager persistence should be done in the background.
+/// * Calling `ChannelManager::timer_tick_occurred()` and
+///   `PeerManager::timer_tick_occurred()` every minute (can be done in the
+///   background).
+///
+/// Note that if ChannelManager persistence fails and the persisted manager becomes out-of-date,
+/// then there is a risk of channels force-closing on startup when the manager realizes it's
+/// outdated. However, as long as `ChannelMonitor` backups are sound, no funds besides those used
+/// for unilateral chain closure fees are at risk.
+pub struct BackgroundProcessor {
+       stop_thread: Arc<AtomicBool>,
+       /// May be used to retrieve and handle the error if `BackgroundProcessor`'s thread
+       /// exits due to an error while persisting.
+       pub thread_handle: JoinHandle<Result<(), std::io::Error>>,
+}
+
+#[cfg(not(test))]
+const FRESHNESS_TIMER: u64 = 60;
+#[cfg(test)]
+const FRESHNESS_TIMER: u64 = 1;
+
+/// Trait which handles persisting a [`ChannelManager`] to disk.
+///
+/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
+pub trait ChannelManagerPersister<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
+where
+       M::Target: 'static + chain::Watch<Signer>,
+       T::Target: 'static + BroadcasterInterface,
+       K::Target: 'static + KeysInterface<Signer = Signer>,
+       F::Target: 'static + FeeEstimator,
+       L::Target: 'static + Logger,
+{
+       /// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed
+       /// (which will cause the [`BackgroundProcessor`] which called this method to exit.
+       ///
+       /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
+       fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>;
+}
+
+impl<Fun, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
+ChannelManagerPersister<Signer, M, T, K, F, L> for Fun where
+       M::Target: 'static + chain::Watch<Signer>,
+       T::Target: 'static + BroadcasterInterface,
+       K::Target: 'static + KeysInterface<Signer = Signer>,
+       F::Target: 'static + FeeEstimator,
+       L::Target: 'static + Logger,
+       Fun: Fn(&ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>,
+{
+       fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error> {
+               self(channel_manager)
+       }
+}
+
+impl BackgroundProcessor {
+       /// Start a background thread that takes care of responsibilities enumerated in the top-level
+       /// documentation.
+       ///
+       /// If `persist_manager` returns an error, then this thread will return said error (and
+       /// `start()` will need to be called again to restart the `BackgroundProcessor`). Users should
+       /// wait on [`thread_handle`]'s `join()` method to be able to tell if and when an error is
+       /// returned, or implement `persist_manager` such that an error is never returned to the
+       /// `BackgroundProcessor`
+       ///
+       /// `persist_manager` is responsible for writing out the [`ChannelManager`] to disk, and/or
+       /// uploading to one or more backup services. See [`ChannelManager::write`] for writing out a
+       /// [`ChannelManager`]. See [`FilesystemPersister::persist_manager`] for Rust-Lightning's
+       /// provided implementation.
+       ///
+       /// [`thread_handle`]: BackgroundProcessor::thread_handle
+       /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
+       /// [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
+       /// [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
+       pub fn start<
+               Signer: 'static + Sign,
+               M: 'static + Deref + Send + Sync,
+               T: 'static + Deref + Send + Sync,
+               K: 'static + Deref + Send + Sync,
+               F: 'static + Deref + Send + Sync,
+               L: 'static + Deref + Send + Sync,
+               Descriptor: 'static + SocketDescriptor + Send + Sync,
+               CMH: 'static + Deref + Send + Sync,
+               RMH: 'static + Deref + Send + Sync,
+               CMP: 'static + Send + ChannelManagerPersister<Signer, M, T, K, F, L>,
+               CM: 'static + Deref<Target = ChannelManager<Signer, M, T, K, F, L>> + Send + Sync,
+               PM: 'static + Deref<Target = PeerManager<Descriptor, CMH, RMH, L>> + Send + Sync,
+       >
+       (handler: CMP, channel_manager: CM, peer_manager: PM, logger: L) -> Self
+       where
+               M::Target: 'static + chain::Watch<Signer>,
+               T::Target: 'static + BroadcasterInterface,
+               K::Target: 'static + KeysInterface<Signer = Signer>,
+               F::Target: 'static + FeeEstimator,
+               L::Target: 'static + Logger,
+               CMH::Target: 'static + ChannelMessageHandler,
+               RMH::Target: 'static + RoutingMessageHandler,
+       {
+               let stop_thread = Arc::new(AtomicBool::new(false));
+               let stop_thread_clone = stop_thread.clone();
+               let handle = thread::spawn(move || -> Result<(), std::io::Error> {
+                       let mut current_time = Instant::now();
+                       loop {
+                               peer_manager.process_events();
+                               let updates_available =
+                                       channel_manager.await_persistable_update_timeout(Duration::from_millis(100));
+                               if updates_available {
+                                       handler.persist_manager(&*channel_manager)?;
+                               }
+                               // Exit the loop if the background processor was requested to stop.
+                               if stop_thread.load(Ordering::Acquire) == true {
+                                       log_trace!(logger, "Terminating background processor.");
+                                       return Ok(());
+                               }
+                               if current_time.elapsed().as_secs() > FRESHNESS_TIMER {
+                                       log_trace!(logger, "Calling ChannelManager's and PeerManager's timer_tick_occurred");
+                                       channel_manager.timer_tick_occurred();
+                                       peer_manager.timer_tick_occurred();
+                                       current_time = Instant::now();
+                               }
+                       }
+               });
+               Self { stop_thread: stop_thread_clone, thread_handle: handle }
+       }
+
+       /// Stop `BackgroundProcessor`'s thread.
+       pub fn stop(self) -> Result<(), std::io::Error> {
+               self.stop_thread.store(true, Ordering::Release);
+               self.thread_handle.join().unwrap()
+       }
+}
+
+#[cfg(test)]
+mod tests {
+       use bitcoin::blockdata::constants::genesis_block;
+       use bitcoin::blockdata::transaction::{Transaction, TxOut};
+       use bitcoin::network::constants::Network;
+       use lightning::chain;
+       use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
+       use lightning::chain::chainmonitor;
+       use lightning::chain::keysinterface::{Sign, InMemorySigner, KeysInterface, KeysManager};
+       use lightning::chain::transaction::OutPoint;
+       use lightning::get_event_msg;
+       use lightning::ln::channelmanager::{BestBlock, ChainParameters, ChannelManager, SimpleArcChannelManager};
+       use lightning::ln::features::InitFeatures;
+       use lightning::ln::msgs::ChannelMessageHandler;
+       use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor};
+       use lightning::util::config::UserConfig;
+       use lightning::util::events::{Event, EventsProvider, MessageSendEventsProvider, MessageSendEvent};
+       use lightning::util::logger::Logger;
+       use lightning::util::ser::Writeable;
+       use lightning::util::test_utils;
+       use lightning_persister::FilesystemPersister;
+       use std::fs;
+       use std::path::PathBuf;
+       use std::sync::{Arc, Mutex};
+       use std::time::Duration;
+       use super::BackgroundProcessor;
+
+       #[derive(Clone, Eq, Hash, PartialEq)]
+       struct TestDescriptor{}
+       impl SocketDescriptor for TestDescriptor {
+               fn send_data(&mut self, _data: &[u8], _resume_read: bool) -> usize {
+                       0
+               }
+
+               fn disconnect_socket(&mut self) {}
+       }
+
+       type ChainMonitor = chainmonitor::ChainMonitor<InMemorySigner, Arc<test_utils::TestChainSource>, Arc<test_utils::TestBroadcaster>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>, Arc<FilesystemPersister>>;
+
+       struct Node {
+               node: Arc<SimpleArcChannelManager<ChainMonitor, test_utils::TestBroadcaster, test_utils::TestFeeEstimator, test_utils::TestLogger>>,
+               peer_manager: Arc<PeerManager<TestDescriptor, Arc<test_utils::TestChannelMessageHandler>, Arc<test_utils::TestRoutingMessageHandler>, Arc<test_utils::TestLogger>>>,
+               persister: Arc<FilesystemPersister>,
+               logger: Arc<test_utils::TestLogger>,
+       }
+
+       impl Drop for Node {
+               fn drop(&mut self) {
+                       let data_dir = self.persister.get_data_dir();
+                       match fs::remove_dir_all(data_dir.clone()) {
+                               Err(e) => println!("Failed to remove test persister directory {}: {}", data_dir, e),
+                               _ => {}
+                       }
+               }
+       }
+
+       fn get_full_filepath(filepath: String, filename: String) -> String {
+               let mut path = PathBuf::from(filepath);
+               path.push(filename);
+               path.to_str().unwrap().to_string()
+       }
+
+       fn create_nodes(num_nodes: usize, persist_dir: String) -> Vec<Node> {
+               let mut nodes = Vec::new();
+               for i in 0..num_nodes {
+                       let tx_broadcaster = Arc::new(test_utils::TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())});
+                       let fee_estimator = Arc::new(test_utils::TestFeeEstimator { sat_per_kw: 253 });
+                       let chain_source = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
+                       let logger = Arc::new(test_utils::TestLogger::with_id(format!("node {}", i)));
+                       let persister = Arc::new(FilesystemPersister::new(format!("{}_persister_{}", persist_dir, i)));
+                       let seed = [i as u8; 32];
+                       let network = Network::Testnet;
+                       let now = Duration::from_secs(genesis_block(network).header.time as u64);
+                       let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_nanos()));
+                       let chain_monitor = Arc::new(chainmonitor::ChainMonitor::new(Some(chain_source.clone()), tx_broadcaster.clone(), logger.clone(), fee_estimator.clone(), persister.clone()));
+                       let params = ChainParameters {
+                               network,
+                               best_block: BestBlock::from_genesis(network),
+                       };
+                       let manager = Arc::new(ChannelManager::new(fee_estimator.clone(), chain_monitor.clone(), tx_broadcaster, logger.clone(), keys_manager.clone(), UserConfig::default(), params));
+                       let msg_handler = MessageHandler { chan_handler: Arc::new(test_utils::TestChannelMessageHandler::new()), route_handler: Arc::new(test_utils::TestRoutingMessageHandler::new() )};
+                       let peer_manager = Arc::new(PeerManager::new(msg_handler, keys_manager.get_node_secret(), &seed, logger.clone()));
+                       let node = Node { node: manager, peer_manager, persister, logger };
+                       nodes.push(node);
+               }
+               nodes
+       }
+
+       macro_rules! open_channel {
+               ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
+                       $node_a.node.create_channel($node_b.node.get_our_node_id(), $channel_value, 100, 42, None).unwrap();
+                       $node_b.node.handle_open_channel(&$node_a.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_a, MessageSendEvent::SendOpenChannel, $node_b.node.get_our_node_id()));
+                       $node_a.node.handle_accept_channel(&$node_b.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_b, MessageSendEvent::SendAcceptChannel, $node_a.node.get_our_node_id()));
+                       let events = $node_a.node.get_and_clear_pending_events();
+                       assert_eq!(events.len(), 1);
+                       let (temporary_channel_id, tx) = match events[0] {
+                               Event::FundingGenerationReady { ref temporary_channel_id, ref channel_value_satoshis, ref output_script, user_channel_id } => {
+                                       assert_eq!(*channel_value_satoshis, $channel_value);
+                                       assert_eq!(user_channel_id, 42);
+
+                                       let tx = Transaction { version: 1 as i32, lock_time: 0, input: Vec::new(), output: vec![TxOut {
+                                               value: *channel_value_satoshis, script_pubkey: output_script.clone(),
+                                       }]};
+                                       (*temporary_channel_id, tx)
+                               },
+                               _ => panic!("Unexpected event"),
+                       };
+
+                       $node_a.node.funding_transaction_generated(&temporary_channel_id, tx.clone()).unwrap();
+                       $node_b.node.handle_funding_created(&$node_a.node.get_our_node_id(), &get_event_msg!($node_a, MessageSendEvent::SendFundingCreated, $node_b.node.get_our_node_id()));
+                       $node_a.node.handle_funding_signed(&$node_b.node.get_our_node_id(), &get_event_msg!($node_b, MessageSendEvent::SendFundingSigned, $node_a.node.get_our_node_id()));
+                       tx
+               }}
+       }
+
+       #[test]
+       fn test_background_processor() {
+               // Test that when a new channel is created, the ChannelManager needs to be re-persisted with
+               // updates. Also test that when new updates are available, the manager signals that it needs
+               // re-persistence and is successfully re-persisted.
+               let nodes = create_nodes(2, "test_background_processor".to_string());
+
+               // Initiate the background processors to watch each node.
+               let data_dir = nodes[0].persister.get_data_dir();
+               let callback = move |node: &ChannelManager<InMemorySigner, Arc<ChainMonitor>, Arc<test_utils::TestBroadcaster>, Arc<KeysManager>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>>| FilesystemPersister::persist_manager(data_dir.clone(), node);
+               let bg_processor = BackgroundProcessor::start(callback, nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
+
+               // Go through the channel creation process until each node should have something persisted.
+               let tx = open_channel!(nodes[0], nodes[1], 100000);
+
+               macro_rules! check_persisted_data {
+                       ($node: expr, $filepath: expr, $expected_bytes: expr) => {
+                               match $node.write(&mut $expected_bytes) {
+                                       Ok(()) => {
+                                               loop {
+                                                       match std::fs::read($filepath) {
+                                                               Ok(bytes) => {
+                                                                       if bytes == $expected_bytes {
+                                                                               break
+                                                                       } else {
+                                                                               continue
+                                                                       }
+                                                               },
+                                                               Err(_) => continue
+                                                       }
+                                               }
+                                       },
+                                       Err(e) => panic!("Unexpected error: {}", e)
+                               }
+                       }
+               }
+
+               // Check that the initial channel manager data is persisted as expected.
+               let filepath = get_full_filepath("test_background_processor_persister_0".to_string(), "manager".to_string());
+               let mut expected_bytes = Vec::new();
+               check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
+               loop {
+                       if !nodes[0].node.get_persistence_condvar_value() { break }
+               }
+
+               // Force-close the channel.
+               nodes[0].node.force_close_channel(&OutPoint { txid: tx.txid(), index: 0 }.to_channel_id()).unwrap();
+
+               // Check that the force-close updates are persisted.
+               let mut expected_bytes = Vec::new();
+               check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
+               loop {
+                       if !nodes[0].node.get_persistence_condvar_value() { break }
+               }
+
+               assert!(bg_processor.stop().is_ok());
+       }
+
+       #[test]
+       fn test_timer_tick_called() {
+               // Test that ChannelManager's and PeerManager's `timer_tick_occurred` is called every
+               // `FRESHNESS_TIMER`.
+               let nodes = create_nodes(1, "test_timer_tick_called".to_string());
+               let data_dir = nodes[0].persister.get_data_dir();
+               let callback = move |node: &ChannelManager<InMemorySigner, Arc<ChainMonitor>, Arc<test_utils::TestBroadcaster>, Arc<KeysManager>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>>| FilesystemPersister::persist_manager(data_dir.clone(), node);
+               let bg_processor = BackgroundProcessor::start(callback, nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
+               loop {
+                       let log_entries = nodes[0].logger.lines.lock().unwrap();
+                       let desired_log = "Calling ChannelManager's and PeerManager's timer_tick_occurred".to_string();
+                       if log_entries.get(&("lightning_background_processor".to_string(), desired_log)).is_some() {
+                               break
+                       }
+               }
+
+               assert!(bg_processor.stop().is_ok());
+       }
+
+       #[test]
+       fn test_persist_error() {
+               // Test that if we encounter an error during manager persistence, the thread panics.
+               fn persist_manager<Signer, M, T, K, F, L>(_data: &ChannelManager<Signer, Arc<M>, Arc<T>, Arc<K>, Arc<F>, Arc<L>>) -> Result<(), std::io::Error>
+               where Signer: 'static + Sign,
+                     M: 'static + chain::Watch<Signer>,
+                     T: 'static + BroadcasterInterface,
+                     K: 'static + KeysInterface<Signer=Signer>,
+                     F: 'static + FeeEstimator,
+                     L: 'static + Logger,
+               {
+                       Err(std::io::Error::new(std::io::ErrorKind::Other, "test"))
+               }
+
+               let nodes = create_nodes(2, "test_persist_error".to_string());
+               let bg_processor = BackgroundProcessor::start(persist_manager, nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
+               open_channel!(nodes[0], nodes[1], 100000);
+
+               let _ = bg_processor.thread_handle.join().unwrap().expect_err("Errored persisting manager: test");
+       }
+}