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  38 /// Note that if ChannelManager persistence fails and the persisted manager becomes out-of-date,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  40 /// outdated.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