_ Git - rust-lightning/blob - lightning-background-processor/src/lib.rs

   1 //! Utilities that take care of tasks that (1) need to happen periodically to keep Rust-Lightning
   2 //! running properly, and (2) either can or should be run in the background. See docs for
   3 //! [`BackgroundProcessor`] for more details on the nitty-gritty.
   4
   5 #![deny(broken_intra_doc_links)]
   6 #![deny(missing_docs)]
   7 #![deny(unsafe_code)]
   8
   9 #[macro_use] extern crate lightning;
  10
  11 use lightning::chain;
  12 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
  13 use lightning::chain::chainmonitor::ChainMonitor;
  14 use lightning::chain::channelmonitor;
  15 use lightning::chain::keysinterface::{Sign, KeysInterface};
  16 use lightning::ln::channelmanager::ChannelManager;
  17 use lightning::ln::msgs::{ChannelMessageHandler, RoutingMessageHandler};
  18 use lightning::ln::peer_handler::{PeerManager, SocketDescriptor};
  19 use lightning::util::events::{EventHandler, EventsProvider};
  20 use lightning::util::logger::Logger;
  21 use std::sync::Arc;
  22 use std::sync::atomic::{AtomicBool, Ordering};
  23 use std::thread;
  24 use std::thread::JoinHandle;
  25 use std::time::{Duration, Instant};
  26 use std::ops::Deref;
  27
  28 /// BackgroundProcessor takes care of tasks that (1) need to happen periodically to keep
  29 /// Rust-Lightning running properly, and (2) either can or should be run in the background. Its
  30 /// responsibilities are:
  31 /// * Monitoring whether the ChannelManager needs to be re-persisted to disk, and if so,
  32 ///   writing it to disk/backups by invoking the callback given to it at startup.
  33 ///   ChannelManager persistence should be done in the background.
  34 /// * Calling `ChannelManager::timer_tick_occurred()` and
  35 ///   `PeerManager::timer_tick_occurred()` every minute (can be done in the
  36 ///   background).
  37 ///
  38 /// Note that if ChannelManager persistence fails and the persisted manager becomes out-of-date,
  39 /// then there is a risk of channels force-closing on startup when the manager realizes it's
  40 /// outdated. However, as long as `ChannelMonitor` backups are sound, no funds besides those used
  41 /// for unilateral chain closure fees are at risk.
  42 #[must_use = "BackgroundProcessor will immediately stop on drop. It should be stored until shutdown."]
  43 pub struct BackgroundProcessor {
  44         stop_thread: Arc<AtomicBool>,
  45         thread_handle: Option<JoinHandle<Result<(), std::io::Error>>>,
  46 }
  47
  48 #[cfg(not(test))]
  49 const FRESHNESS_TIMER: u64 = 60;
  50 #[cfg(test)]
  51 const FRESHNESS_TIMER: u64 = 1;
  52
  53 const PING_TIMER: u64 = 5;
  54
  55 /// Trait which handles persisting a [`ChannelManager`] to disk.
  56 ///
  57 /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
  58 pub trait ChannelManagerPersister<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
  59 where
  60         M::Target: 'static + chain::Watch<Signer>,
  61         T::Target: 'static + BroadcasterInterface,
  62         K::Target: 'static + KeysInterface<Signer = Signer>,
  63         F::Target: 'static + FeeEstimator,
  64         L::Target: 'static + Logger,
  65 {
  66         /// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed
  67         /// (which will cause the [`BackgroundProcessor`] which called this method to exit.
  68         ///
  69         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
  70         fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>;
  71 }
  72
  73 impl<Fun, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
  74 ChannelManagerPersister<Signer, M, T, K, F, L> for Fun where
  75         M::Target: 'static + chain::Watch<Signer>,
  76         T::Target: 'static + BroadcasterInterface,
  77         K::Target: 'static + KeysInterface<Signer = Signer>,
  78         F::Target: 'static + FeeEstimator,
  79         L::Target: 'static + Logger,
  80         Fun: Fn(&ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>,
  81 {
  82         fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error> {
  83                 self(channel_manager)
  84         }
  85 }
  86
  87 impl BackgroundProcessor {
  88         /// Start a background thread that takes care of responsibilities enumerated in the [top-level
  89         /// documentation].
  90         ///
  91         /// The thread runs indefinitely unless the object is dropped, [`stop`] is called, or
  92         /// `persist_manager` returns an error. In case of an error, the error is retrieved by calling
  93         /// either [`join`] or [`stop`].
  94         ///
  95         /// Typically, users should either implement [`ChannelManagerPersister`] to never return an
  96         /// error or call [`join`] and handle any error that may arise. For the latter case, the
  97         /// `BackgroundProcessor` must be restarted by calling `start` again after handling the error.
  98         ///
  99         /// `persist_manager` is responsible for writing out the [`ChannelManager`] to disk, and/or
 100         /// uploading to one or more backup services. See [`ChannelManager::write`] for writing out a
 101         /// [`ChannelManager`]. See [`FilesystemPersister::persist_manager`] for Rust-Lightning's
 102         /// provided implementation.
 103         ///
 104         /// [top-level documentation]: Self
 105         /// [`join`]: Self::join
 106         /// [`stop`]: Self::stop
 107         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 108         /// [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
 109         /// [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
 110         pub fn start<
 111                 Signer: 'static + Sign,
 112                 CF: 'static + Deref + Send + Sync,
 113                 CW: 'static + Deref + Send + Sync,
 114                 T: 'static + Deref + Send + Sync,
 115                 K: 'static + Deref + Send + Sync,
 116                 F: 'static + Deref + Send + Sync,
 117                 L: 'static + Deref + Send + Sync,
 118                 P: 'static + Deref + Send + Sync,
 119                 Descriptor: 'static + SocketDescriptor + Send + Sync,
 120                 CMH: 'static + Deref + Send + Sync,
 121                 RMH: 'static + Deref + Send + Sync,
 122                 EH: 'static + EventHandler + Send + Sync,
 123                 CMP: 'static + Send + ChannelManagerPersister<Signer, CW, T, K, F, L>,
 124                 M: 'static + Deref<Target = ChainMonitor<Signer, CF, T, F, L, P>> + Send + Sync,
 125                 CM: 'static + Deref<Target = ChannelManager<Signer, CW, T, K, F, L>> + Send + Sync,
 126                 PM: 'static + Deref<Target = PeerManager<Descriptor, CMH, RMH, L>> + Send + Sync,
 127         >
 128         (persister: CMP, event_handler: EH, chain_monitor: M, channel_manager: CM, peer_manager: PM, logger: L) -> Self
 129         where
 130                 CF::Target: 'static + chain::Filter,
 131                 CW::Target: 'static + chain::Watch<Signer>,
 132                 T::Target: 'static + BroadcasterInterface,
 133                 K::Target: 'static + KeysInterface<Signer = Signer>,
 134                 F::Target: 'static + FeeEstimator,
 135                 L::Target: 'static + Logger,
 136                 P::Target: 'static + channelmonitor::Persist<Signer>,
 137                 CMH::Target: 'static + ChannelMessageHandler,
 138                 RMH::Target: 'static + RoutingMessageHandler,
 139         {
 140                 let stop_thread = Arc::new(AtomicBool::new(false));
 141                 let stop_thread_clone = stop_thread.clone();
 142                 let handle = thread::spawn(move || -> Result<(), std::io::Error> {
 143                         log_trace!(logger, "Calling ChannelManager's timer_tick_occurred on startup");
 144                         channel_manager.timer_tick_occurred();
 145
 146                         let mut last_freshness_call = Instant::now();
 147                         let mut last_ping_call = Instant::now();
 148                         loop {
 149                                 peer_manager.process_events();
 150                                 channel_manager.process_pending_events(&event_handler);
 151                                 chain_monitor.process_pending_events(&event_handler);
 152                                 let updates_available =
 153                                         channel_manager.await_persistable_update_timeout(Duration::from_millis(100));
 154                                 if updates_available {
 155                                         persister.persist_manager(&*channel_manager)?;
 156                                 }
 157                                 // Exit the loop if the background processor was requested to stop.
 158                                 if stop_thread.load(Ordering::Acquire) == true {
 159                                         log_trace!(logger, "Terminating background processor.");
 160                                         return Ok(());
 161                                 }
 162                                 if last_freshness_call.elapsed().as_secs() > FRESHNESS_TIMER {
 163                                         log_trace!(logger, "Calling ChannelManager's timer_tick_occurred");
 164                                         channel_manager.timer_tick_occurred();
 165                                         last_freshness_call = Instant::now();
 166                                 }
 167                                 if last_ping_call.elapsed().as_secs() > PING_TIMER * 2 {
 168                                         // On various platforms, we may be starved of CPU cycles for several reasons.
 169                                         // E.g. on iOS, if we've been in the background, we will be entirely paused.
 170                                         // Similarly, if we're on a desktop platform and the device has been asleep, we
 171                                         // may not get any cycles.
 172                                         // In any case, if we've been entirely paused for more than double our ping
 173                                         // timer, we should have disconnected all sockets by now (and they're probably
 174                                         // dead anyway), so disconnect them by calling `timer_tick_occurred()` twice.
 175                                         log_trace!(logger, "Awoke after more than double our ping timer, disconnecting peers.");
 176                                         peer_manager.timer_tick_occurred();
 177                                         peer_manager.timer_tick_occurred();
 178                                         last_ping_call = Instant::now();
 179                                 } else if last_ping_call.elapsed().as_secs() > PING_TIMER {
 180                                         log_trace!(logger, "Calling PeerManager's timer_tick_occurred");
 181                                         peer_manager.timer_tick_occurred();
 182                                         last_ping_call = Instant::now();
 183                                 }
 184                         }
 185                 });
 186                 Self { stop_thread: stop_thread_clone, thread_handle: Some(handle) }
 187         }
 188
 189         /// Join `BackgroundProcessor`'s thread, returning any error that occurred while persisting
 190         /// [`ChannelManager`].
 191         ///
 192         /// # Panics
 193         ///
 194         /// This function panics if the background thread has panicked such as while persisting or
 195         /// handling events.
 196         ///
 197         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 198         pub fn join(mut self) -> Result<(), std::io::Error> {
 199                 assert!(self.thread_handle.is_some());
 200                 self.join_thread()
 201         }
 202
 203         /// Stop `BackgroundProcessor`'s thread, returning any error that occurred while persisting
 204         /// [`ChannelManager`].
 205         ///
 206         /// # Panics
 207         ///
 208         /// This function panics if the background thread has panicked such as while persisting or
 209         /// handling events.
 210         ///
 211         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 212         pub fn stop(mut self) -> Result<(), std::io::Error> {
 213                 assert!(self.thread_handle.is_some());
 214                 self.stop_and_join_thread()
 215         }
 216
 217         fn stop_and_join_thread(&mut self) -> Result<(), std::io::Error> {
 218                 self.stop_thread.store(true, Ordering::Release);
 219                 self.join_thread()
 220         }
 221
 222         fn join_thread(&mut self) -> Result<(), std::io::Error> {
 223                 match self.thread_handle.take() {
 224                         Some(handle) => handle.join().unwrap(),
 225                         None => Ok(()),
 226                 }
 227         }
 228 }
 229
 230 impl Drop for BackgroundProcessor {
 231         fn drop(&mut self) {
 232                 self.stop_and_join_thread().unwrap();
 233         }
 234 }
 235
 236 #[cfg(test)]
 237 mod tests {
 238         use bitcoin::blockdata::block::BlockHeader;
 239         use bitcoin::blockdata::constants::genesis_block;
 240         use bitcoin::blockdata::transaction::{Transaction, TxOut};
 241         use bitcoin::network::constants::Network;
 242         use lightning::chain::{BestBlock, Confirm, chainmonitor};
 243         use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
 244         use lightning::chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager};
 245         use lightning::chain::transaction::OutPoint;
 246         use lightning::get_event_msg;
 247         use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, ChainParameters, ChannelManager, SimpleArcChannelManager};
 248         use lightning::ln::features::InitFeatures;
 249         use lightning::ln::msgs::{ChannelMessageHandler, Init};
 250         use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor};
 251         use lightning::util::config::UserConfig;
 252         use lightning::util::events::{Event, MessageSendEventsProvider, MessageSendEvent};
 253         use lightning::util::ser::Writeable;
 254         use lightning::util::test_utils;
 255         use lightning_persister::FilesystemPersister;
 256         use std::fs;
 257         use std::path::PathBuf;
 258         use std::sync::{Arc, Mutex};
 259         use std::time::Duration;
 260         use super::{BackgroundProcessor, FRESHNESS_TIMER};
 261
 262         const EVENT_DEADLINE: u64 = 5 * FRESHNESS_TIMER;
 263
 264         #[derive(Clone, Eq, Hash, PartialEq)]
 265         struct TestDescriptor{}
 266         impl SocketDescriptor for TestDescriptor {
 267                 fn send_data(&mut self, _data: &[u8], _resume_read: bool) -> usize {
 268                         0
 269                 }
 270
 271                 fn disconnect_socket(&mut self) {}
 272         }
 273
 274         type ChainMonitor = chainmonitor::ChainMonitor<InMemorySigner, Arc<test_utils::TestChainSource>, Arc<test_utils::TestBroadcaster>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>, Arc<FilesystemPersister>>;
 275
 276         struct Node {
 277                 node: Arc<SimpleArcChannelManager<ChainMonitor, test_utils::TestBroadcaster, test_utils::TestFeeEstimator, test_utils::TestLogger>>,
 278                 peer_manager: Arc<PeerManager<TestDescriptor, Arc<test_utils::TestChannelMessageHandler>, Arc<test_utils::TestRoutingMessageHandler>, Arc<test_utils::TestLogger>>>,
 279                 chain_monitor: Arc<ChainMonitor>,
 280                 persister: Arc<FilesystemPersister>,
 281                 tx_broadcaster: Arc<test_utils::TestBroadcaster>,
 282                 logger: Arc<test_utils::TestLogger>,
 283                 best_block: BestBlock,
 284         }
 285
 286         impl Drop for Node {
 287                 fn drop(&mut self) {
 288                         let data_dir = self.persister.get_data_dir();
 289                         match fs::remove_dir_all(data_dir.clone()) {
 290                                 Err(e) => println!("Failed to remove test persister directory {}: {}", data_dir, e),
 291                                 _ => {}
 292                         }
 293                 }
 294         }
 295
 296         fn get_full_filepath(filepath: String, filename: String) -> String {
 297                 let mut path = PathBuf::from(filepath);
 298                 path.push(filename);
 299                 path.to_str().unwrap().to_string()
 300         }
 301
 302         fn create_nodes(num_nodes: usize, persist_dir: String) -> Vec<Node> {
 303                 let mut nodes = Vec::new();
 304                 for i in 0..num_nodes {
 305                         let tx_broadcaster = Arc::new(test_utils::TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
 306                         let fee_estimator = Arc::new(test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) });
 307                         let chain_source = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
 308                         let logger = Arc::new(test_utils::TestLogger::with_id(format!("node {}", i)));
 309                         let persister = Arc::new(FilesystemPersister::new(format!("{}_persister_{}", persist_dir, i)));
 310                         let seed = [i as u8; 32];
 311                         let network = Network::Testnet;
 312                         let now = Duration::from_secs(genesis_block(network).header.time as u64);
 313                         let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_nanos()));
 314                         let chain_monitor = Arc::new(chainmonitor::ChainMonitor::new(Some(chain_source.clone()), tx_broadcaster.clone(), logger.clone(), fee_estimator.clone(), persister.clone()));
 315                         let best_block = BestBlock::from_genesis(network);
 316                         let params = ChainParameters { network, best_block };
 317                         let manager = Arc::new(ChannelManager::new(fee_estimator.clone(), chain_monitor.clone(), tx_broadcaster.clone(), logger.clone(), keys_manager.clone(), UserConfig::default(), params));
 318                         let msg_handler = MessageHandler { chan_handler: Arc::new(test_utils::TestChannelMessageHandler::new()), route_handler: Arc::new(test_utils::TestRoutingMessageHandler::new() )};
 319                         let peer_manager = Arc::new(PeerManager::new(msg_handler, keys_manager.get_node_secret(), &seed, logger.clone()));
 320                         let node = Node { node: manager, peer_manager, chain_monitor, persister, tx_broadcaster, logger, best_block };
 321                         nodes.push(node);
 322                 }
 323
 324                 for i in 0..num_nodes {
 325                         for j in (i+1)..num_nodes {
 326                                 nodes[i].node.peer_connected(&nodes[j].node.get_our_node_id(), &Init { features: InitFeatures::known() });
 327                                 nodes[j].node.peer_connected(&nodes[i].node.get_our_node_id(), &Init { features: InitFeatures::known() });
 328                         }
 329                 }
 330
 331                 nodes
 332         }
 333
 334         macro_rules! open_channel {
 335                 ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
 336                         begin_open_channel!($node_a, $node_b, $channel_value);
 337                         let events = $node_a.node.get_and_clear_pending_events();
 338                         assert_eq!(events.len(), 1);
 339                         let (temporary_channel_id, tx) = handle_funding_generation_ready!(events[0], $channel_value);
 340                         end_open_channel!($node_a, $node_b, temporary_channel_id, tx);
 341                         tx
 342                 }}
 343         }
 344
 345         macro_rules! begin_open_channel {
 346                 ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
 347                         $node_a.node.create_channel($node_b.node.get_our_node_id(), $channel_value, 100, 42, None).unwrap();
 348                         $node_b.node.handle_open_channel(&$node_a.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_a, MessageSendEvent::SendOpenChannel, $node_b.node.get_our_node_id()));
 349                         $node_a.node.handle_accept_channel(&$node_b.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_b, MessageSendEvent::SendAcceptChannel, $node_a.node.get_our_node_id()));
 350                 }}
 351         }
 352
 353         macro_rules! handle_funding_generation_ready {
 354                 ($event: expr, $channel_value: expr) => {{
 355                         match $event {
 356                                 Event::FundingGenerationReady { ref temporary_channel_id, ref channel_value_satoshis, ref output_script, user_channel_id } => {
 357                                         assert_eq!(*channel_value_satoshis, $channel_value);
 358                                         assert_eq!(user_channel_id, 42);
 359
 360                                         let tx = Transaction { version: 1 as i32, lock_time: 0, input: Vec::new(), output: vec![TxOut {
 361                                                 value: *channel_value_satoshis, script_pubkey: output_script.clone(),
 362                                         }]};
 363                                         (*temporary_channel_id, tx)
 364                                 },
 365                                 _ => panic!("Unexpected event"),
 366                         }
 367                 }}
 368         }
 369
 370         macro_rules! end_open_channel {
 371                 ($node_a: expr, $node_b: expr, $temporary_channel_id: expr, $tx: expr) => {{
 372                         $node_a.node.funding_transaction_generated(&$temporary_channel_id, $tx.clone()).unwrap();
 373                         $node_b.node.handle_funding_created(&$node_a.node.get_our_node_id(), &get_event_msg!($node_a, MessageSendEvent::SendFundingCreated, $node_b.node.get_our_node_id()));
 374                         $node_a.node.handle_funding_signed(&$node_b.node.get_our_node_id(), &get_event_msg!($node_b, MessageSendEvent::SendFundingSigned, $node_a.node.get_our_node_id()));
 375                 }}
 376         }
 377
 378         fn confirm_transaction_depth(node: &mut Node, tx: &Transaction, depth: u32) {
 379                 for i in 1..=depth {
 380                         let prev_blockhash = node.best_block.block_hash();
 381                         let height = node.best_block.height() + 1;
 382                         let header = BlockHeader { version: 0x20000000, prev_blockhash, merkle_root: Default::default(), time: height, bits: 42, nonce: 42 };
 383                         let txdata = vec![(0, tx)];
 384                         node.best_block = BestBlock::new(header.block_hash(), height);
 385                         match i {
 386                                 1 => {
 387                                         node.node.transactions_confirmed(&header, &txdata, height);
 388                                         node.chain_monitor.transactions_confirmed(&header, &txdata, height);
 389                                 },
 390                                 x if x == depth => {
 391                                         node.node.best_block_updated(&header, height);
 392                                         node.chain_monitor.best_block_updated(&header, height);
 393                                 },
 394                                 _ => {},
 395                         }
 396                 }
 397         }
 398         fn confirm_transaction(node: &mut Node, tx: &Transaction) {
 399                 confirm_transaction_depth(node, tx, ANTI_REORG_DELAY);
 400         }
 401
 402         #[test]
 403         fn test_background_processor() {
 404                 // Test that when a new channel is created, the ChannelManager needs to be re-persisted with
 405                 // updates. Also test that when new updates are available, the manager signals that it needs
 406                 // re-persistence and is successfully re-persisted.
 407                 let nodes = create_nodes(2, "test_background_processor".to_string());
 408
 409                 // Go through the channel creation process so that each node has something to persist. Since
 410                 // open_channel consumes events, it must complete before starting BackgroundProcessor to
 411                 // avoid a race with processing events.
 412                 let tx = open_channel!(nodes[0], nodes[1], 100000);
 413
 414                 // Initiate the background processors to watch each node.
 415                 let data_dir = nodes[0].persister.get_data_dir();
 416                 let persister = 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);
 417                 let event_handler = |_| {};
 418                 let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 419
 420                 macro_rules! check_persisted_data {
 421                         ($node: expr, $filepath: expr, $expected_bytes: expr) => {
 422                                 match $node.write(&mut $expected_bytes) {
 423                                         Ok(()) => {
 424                                                 loop {
 425                                                         match std::fs::read($filepath) {
 426                                                                 Ok(bytes) => {
 427                                                                         if bytes == $expected_bytes {
 428                                                                                 break
 429                                                                         } else {
 430                                                                                 continue
 431                                                                         }
 432                                                                 },
 433                                                                 Err(_) => continue
 434                                                         }
 435                                                 }
 436                                         },
 437                                         Err(e) => panic!("Unexpected error: {}", e)
 438                                 }
 439                         }
 440                 }
 441
 442                 // Check that the initial channel manager data is persisted as expected.
 443                 let filepath = get_full_filepath("test_background_processor_persister_0".to_string(), "manager".to_string());
 444                 let mut expected_bytes = Vec::new();
 445                 check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
 446                 loop {
 447                         if !nodes[0].node.get_persistence_condvar_value() { break }
 448                 }
 449
 450                 // Force-close the channel.
 451                 nodes[0].node.force_close_channel(&OutPoint { txid: tx.txid(), index: 0 }.to_channel_id()).unwrap();
 452
 453                 // Check that the force-close updates are persisted.
 454                 let mut expected_bytes = Vec::new();
 455                 check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
 456                 loop {
 457                         if !nodes[0].node.get_persistence_condvar_value() { break }
 458                 }
 459
 460                 assert!(bg_processor.stop().is_ok());
 461         }
 462
 463         #[test]
 464         fn test_timer_tick_called() {
 465                 // Test that ChannelManager's and PeerManager's `timer_tick_occurred` is called every
 466                 // `FRESHNESS_TIMER`.
 467                 let nodes = create_nodes(1, "test_timer_tick_called".to_string());
 468                 let data_dir = nodes[0].persister.get_data_dir();
 469                 let persister = 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);
 470                 let event_handler = |_| {};
 471                 let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 472                 loop {
 473                         let log_entries = nodes[0].logger.lines.lock().unwrap();
 474                         let desired_log = "Calling ChannelManager's timer_tick_occurred".to_string();
 475                         let second_desired_log = "Calling PeerManager's timer_tick_occurred".to_string();
 476                         if log_entries.get(&("lightning_background_processor".to_string(), desired_log)).is_some() &&
 477                                         log_entries.get(&("lightning_background_processor".to_string(), second_desired_log)).is_some() {
 478                                 break
 479                         }
 480                 }
 481
 482                 assert!(bg_processor.stop().is_ok());
 483         }
 484
 485         #[test]
 486         fn test_persist_error() {
 487                 // Test that if we encounter an error during manager persistence, the thread panics.
 488                 let nodes = create_nodes(2, "test_persist_error".to_string());
 489                 open_channel!(nodes[0], nodes[1], 100000);
 490
 491                 let persister = |_: &_| Err(std::io::Error::new(std::io::ErrorKind::Other, "test"));
 492                 let event_handler = |_| {};
 493                 let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 494                 match bg_processor.join() {
 495                         Ok(_) => panic!("Expected error persisting manager"),
 496                         Err(e) => {
 497                                 assert_eq!(e.kind(), std::io::ErrorKind::Other);
 498                                 assert_eq!(e.get_ref().unwrap().to_string(), "test");
 499                         },
 500                 }
 501         }
 502
 503         #[test]
 504         fn test_background_event_handling() {
 505                 let mut nodes = create_nodes(2, "test_background_event_handling".to_string());
 506                 let channel_value = 100000;
 507                 let data_dir = nodes[0].persister.get_data_dir();
 508                 let persister = move |node: &_| FilesystemPersister::persist_manager(data_dir.clone(), node);
 509
 510                 // Set up a background event handler for FundingGenerationReady events.
 511                 let (sender, receiver) = std::sync::mpsc::sync_channel(1);
 512                 let event_handler = move |event| {
 513                         sender.send(handle_funding_generation_ready!(event, channel_value)).unwrap();
 514                 };
 515                 let bg_processor = BackgroundProcessor::start(persister.clone(), event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 516
 517                 // Open a channel and check that the FundingGenerationReady event was handled.
 518                 begin_open_channel!(nodes[0], nodes[1], channel_value);
 519                 let (temporary_channel_id, funding_tx) = receiver
 520                         .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
 521                         .expect("FundingGenerationReady not handled within deadline");
 522                 end_open_channel!(nodes[0], nodes[1], temporary_channel_id, funding_tx);
 523
 524                 // Confirm the funding transaction.
 525                 confirm_transaction(&mut nodes[0], &funding_tx);
 526                 let as_funding = get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id());
 527                 confirm_transaction(&mut nodes[1], &funding_tx);
 528                 let bs_funding = get_event_msg!(nodes[1], MessageSendEvent::SendFundingLocked, nodes[0].node.get_our_node_id());
 529                 nodes[0].node.handle_funding_locked(&nodes[1].node.get_our_node_id(), &bs_funding);
 530                 let _as_channel_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
 531                 nodes[1].node.handle_funding_locked(&nodes[0].node.get_our_node_id(), &as_funding);
 532                 let _bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
 533
 534                 assert!(bg_processor.stop().is_ok());
 535
 536                 // Set up a background event handler for SpendableOutputs events.
 537                 let (sender, receiver) = std::sync::mpsc::sync_channel(1);
 538                 let event_handler = move |event| sender.send(event).unwrap();
 539                 let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 540
 541                 // Force close the channel and check that the SpendableOutputs event was handled.
 542                 nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id).unwrap();
 543                 let commitment_tx = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().pop().unwrap();
 544                 confirm_transaction_depth(&mut nodes[0], &commitment_tx, BREAKDOWN_TIMEOUT as u32);
 545                 let event = receiver
 546                         .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
 547                         .expect("SpendableOutputs not handled within deadline");
 548                 match event {
 549                         Event::SpendableOutputs { .. } => {},
 550                         _ => panic!("Unexpected event: {:?}", event),
 551                 }
 552
 553                 assert!(bg_processor.stop().is_ok());
 554         }
 555 }