_ 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::ln::peer_handler::CustomMessageHandler;
  20 use lightning::routing::network_graph::NetGraphMsgHandler;
  21 use lightning::util::events::{Event, EventHandler, EventsProvider};
  22 use lightning::util::logger::Logger;
  23 use std::sync::Arc;
  24 use std::sync::atomic::{AtomicBool, Ordering};
  25 use std::thread;
  26 use std::thread::JoinHandle;
  27 use std::time::{Duration, Instant};
  28 use std::ops::Deref;
  29
  30 /// `BackgroundProcessor` takes care of tasks that (1) need to happen periodically to keep
  31 /// Rust-Lightning running properly, and (2) either can or should be run in the background. Its
  32 /// responsibilities are:
  33 /// * Processing [`Event`]s with a user-provided [`EventHandler`].
  34 /// * Monitoring whether the [`ChannelManager`] needs to be re-persisted to disk, and if so,
  35 ///   writing it to disk/backups by invoking the callback given to it at startup.
  36 ///   [`ChannelManager`] persistence should be done in the background.
  37 /// * Calling [`ChannelManager::timer_tick_occurred`] and [`PeerManager::timer_tick_occurred`]
  38 ///   at the appropriate intervals.
  39 ///
  40 /// It will also call [`PeerManager::process_events`] periodically though this shouldn't be relied
  41 /// upon as doing so may result in high latency.
  42 ///
  43 /// # Note
  44 ///
  45 /// If [`ChannelManager`] persistence fails and the persisted manager becomes out-of-date, then
  46 /// there is a risk of channels force-closing on startup when the manager realizes it's outdated.
  47 /// However, as long as [`ChannelMonitor`] backups are sound, no funds besides those used for
  48 /// unilateral chain closure fees are at risk.
  49 ///
  50 /// [`ChannelMonitor`]: lightning::chain::channelmonitor::ChannelMonitor
  51 /// [`Event`]: lightning::util::events::Event
  52 #[must_use = "BackgroundProcessor will immediately stop on drop. It should be stored until shutdown."]
  53 pub struct BackgroundProcessor {
  54         stop_thread: Arc<AtomicBool>,
  55         thread_handle: Option<JoinHandle<Result<(), std::io::Error>>>,
  56 }
  57
  58 #[cfg(not(test))]
  59 const FRESHNESS_TIMER: u64 = 60;
  60 #[cfg(test)]
  61 const FRESHNESS_TIMER: u64 = 1;
  62
  63 #[cfg(not(debug_assertions))]
  64 const PING_TIMER: u64 = 5;
  65 /// Signature operations take a lot longer without compiler optimisations.
  66 /// Increasing the ping timer allows for this but slower devices will be disconnected if the
  67 /// timeout is reached.
  68 #[cfg(debug_assertions)]
  69 const PING_TIMER: u64 = 30;
  70
  71 /// Trait which handles persisting a [`ChannelManager`] to disk.
  72 ///
  73 /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
  74 pub trait ChannelManagerPersister<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
  75 where
  76         M::Target: 'static + chain::Watch<Signer>,
  77         T::Target: 'static + BroadcasterInterface,
  78         K::Target: 'static + KeysInterface<Signer = Signer>,
  79         F::Target: 'static + FeeEstimator,
  80         L::Target: 'static + Logger,
  81 {
  82         /// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed
  83         /// (which will cause the [`BackgroundProcessor`] which called this method to exit.
  84         ///
  85         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
  86         fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>;
  87 }
  88
  89 impl<Fun, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
  90 ChannelManagerPersister<Signer, M, T, K, F, L> for Fun where
  91         M::Target: 'static + chain::Watch<Signer>,
  92         T::Target: 'static + BroadcasterInterface,
  93         K::Target: 'static + KeysInterface<Signer = Signer>,
  94         F::Target: 'static + FeeEstimator,
  95         L::Target: 'static + Logger,
  96         Fun: Fn(&ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>,
  97 {
  98         fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error> {
  99                 self(channel_manager)
 100         }
 101 }
 102
 103 /// Decorates an [`EventHandler`] with common functionality provided by standard [`EventHandler`]s.
 104 struct DecoratingEventHandler<
 105         E: EventHandler,
 106         N: Deref<Target = NetGraphMsgHandler<A, L>>,
 107         A: Deref,
 108         L: Deref,
 109 >
 110 where A::Target: chain::Access, L::Target: Logger {
 111         event_handler: E,
 112         net_graph_msg_handler: Option<N>,
 113 }
 114
 115 impl<
 116         E: EventHandler,
 117         N: Deref<Target = NetGraphMsgHandler<A, L>>,
 118         A: Deref,
 119         L: Deref,
 120 > EventHandler for DecoratingEventHandler<E, N, A, L>
 121 where A::Target: chain::Access, L::Target: Logger {
 122         fn handle_event(&self, event: &Event) {
 123                 if let Some(event_handler) = &self.net_graph_msg_handler {
 124                         event_handler.handle_event(event);
 125                 }
 126                 self.event_handler.handle_event(event);
 127         }
 128 }
 129
 130 impl BackgroundProcessor {
 131         /// Start a background thread that takes care of responsibilities enumerated in the [top-level
 132         /// documentation].
 133         ///
 134         /// The thread runs indefinitely unless the object is dropped, [`stop`] is called, or
 135         /// `persist_manager` returns an error. In case of an error, the error is retrieved by calling
 136         /// either [`join`] or [`stop`].
 137         ///
 138         /// # Data Persistence
 139         ///
 140         /// `persist_manager` is responsible for writing out the [`ChannelManager`] to disk, and/or
 141         /// uploading to one or more backup services. See [`ChannelManager::write`] for writing out a
 142         /// [`ChannelManager`]. See [`FilesystemPersister::persist_manager`] for Rust-Lightning's
 143         /// provided implementation.
 144         ///
 145         /// Typically, users should either implement [`ChannelManagerPersister`] to never return an
 146         /// error or call [`join`] and handle any error that may arise. For the latter case,
 147         /// `BackgroundProcessor` must be restarted by calling `start` again after handling the error.
 148         ///
 149         /// # Event Handling
 150         ///
 151         /// `event_handler` is responsible for handling events that users should be notified of (e.g.,
 152         /// payment failed). [`BackgroundProcessor`] may decorate the given [`EventHandler`] with common
 153         /// functionality implemented by other handlers.
 154         /// * [`NetGraphMsgHandler`] if given will update the [`NetworkGraph`] based on payment failures.
 155         ///
 156         /// [top-level documentation]: Self
 157         /// [`join`]: Self::join
 158         /// [`stop`]: Self::stop
 159         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 160         /// [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
 161         /// [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
 162         /// [`NetworkGraph`]: lightning::routing::network_graph::NetworkGraph
 163         pub fn start<
 164                 Signer: 'static + Sign,
 165                 CA: 'static + Deref + Send + Sync,
 166                 CF: 'static + Deref + Send + Sync,
 167                 CW: 'static + Deref + Send + Sync,
 168                 T: 'static + Deref + Send + Sync,
 169                 K: 'static + Deref + Send + Sync,
 170                 F: 'static + Deref + Send + Sync,
 171                 L: 'static + Deref + Send + Sync,
 172                 P: 'static + Deref + Send + Sync,
 173                 Descriptor: 'static + SocketDescriptor + Send + Sync,
 174                 CMH: 'static + Deref + Send + Sync,
 175                 RMH: 'static + Deref + Send + Sync,
 176                 EH: 'static + EventHandler + Send + Sync,
 177                 CMP: 'static + Send + ChannelManagerPersister<Signer, CW, T, K, F, L>,
 178                 M: 'static + Deref<Target = ChainMonitor<Signer, CF, T, F, L, P>> + Send + Sync,
 179                 CM: 'static + Deref<Target = ChannelManager<Signer, CW, T, K, F, L>> + Send + Sync,
 180                 NG: 'static + Deref<Target = NetGraphMsgHandler<CA, L>> + Send + Sync,
 181                 UMH: 'static + Deref + Send + Sync,
 182                 PM: 'static + Deref<Target = PeerManager<Descriptor, CMH, RMH, L, UMH>> + Send + Sync,
 183         >(
 184                 persister: CMP, event_handler: EH, chain_monitor: M, channel_manager: CM,
 185                 net_graph_msg_handler: Option<NG>, peer_manager: PM, logger: L
 186         ) -> Self
 187         where
 188                 CA::Target: 'static + chain::Access,
 189                 CF::Target: 'static + chain::Filter,
 190                 CW::Target: 'static + chain::Watch<Signer>,
 191                 T::Target: 'static + BroadcasterInterface,
 192                 K::Target: 'static + KeysInterface<Signer = Signer>,
 193                 F::Target: 'static + FeeEstimator,
 194                 L::Target: 'static + Logger,
 195                 P::Target: 'static + channelmonitor::Persist<Signer>,
 196                 CMH::Target: 'static + ChannelMessageHandler,
 197                 RMH::Target: 'static + RoutingMessageHandler,
 198                 UMH::Target: 'static + CustomMessageHandler,
 199         {
 200                 let stop_thread = Arc::new(AtomicBool::new(false));
 201                 let stop_thread_clone = stop_thread.clone();
 202                 let handle = thread::spawn(move || -> Result<(), std::io::Error> {
 203                         let event_handler = DecoratingEventHandler { event_handler, net_graph_msg_handler };
 204
 205                         log_trace!(logger, "Calling ChannelManager's timer_tick_occurred on startup");
 206                         channel_manager.timer_tick_occurred();
 207
 208                         let mut last_freshness_call = Instant::now();
 209                         let mut last_ping_call = Instant::now();
 210                         loop {
 211                                 peer_manager.process_events();
 212                                 channel_manager.process_pending_events(&event_handler);
 213                                 chain_monitor.process_pending_events(&event_handler);
 214                                 let updates_available =
 215                                         channel_manager.await_persistable_update_timeout(Duration::from_millis(100));
 216                                 if updates_available {
 217                                         persister.persist_manager(&*channel_manager)?;
 218                                 }
 219                                 // Exit the loop if the background processor was requested to stop.
 220                                 if stop_thread.load(Ordering::Acquire) == true {
 221                                         log_trace!(logger, "Terminating background processor.");
 222                                         return Ok(());
 223                                 }
 224                                 if last_freshness_call.elapsed().as_secs() > FRESHNESS_TIMER {
 225                                         log_trace!(logger, "Calling ChannelManager's timer_tick_occurred");
 226                                         channel_manager.timer_tick_occurred();
 227                                         last_freshness_call = Instant::now();
 228                                 }
 229                                 if last_ping_call.elapsed().as_secs() > PING_TIMER * 2 {
 230                                         // On various platforms, we may be starved of CPU cycles for several reasons.
 231                                         // E.g. on iOS, if we've been in the background, we will be entirely paused.
 232                                         // Similarly, if we're on a desktop platform and the device has been asleep, we
 233                                         // may not get any cycles.
 234                                         // In any case, if we've been entirely paused for more than double our ping
 235                                         // timer, we should have disconnected all sockets by now (and they're probably
 236                                         // dead anyway), so disconnect them by calling `timer_tick_occurred()` twice.
 237                                         log_trace!(logger, "Awoke after more than double our ping timer, disconnecting peers.");
 238                                         peer_manager.timer_tick_occurred();
 239                                         peer_manager.timer_tick_occurred();
 240                                         last_ping_call = Instant::now();
 241                                 } else if last_ping_call.elapsed().as_secs() > PING_TIMER {
 242                                         log_trace!(logger, "Calling PeerManager's timer_tick_occurred");
 243                                         peer_manager.timer_tick_occurred();
 244                                         last_ping_call = Instant::now();
 245                                 }
 246                         }
 247                 });
 248                 Self { stop_thread: stop_thread_clone, thread_handle: Some(handle) }
 249         }
 250
 251         /// Join `BackgroundProcessor`'s thread, returning any error that occurred while persisting
 252         /// [`ChannelManager`].
 253         ///
 254         /// # Panics
 255         ///
 256         /// This function panics if the background thread has panicked such as while persisting or
 257         /// handling events.
 258         ///
 259         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 260         pub fn join(mut self) -> Result<(), std::io::Error> {
 261                 assert!(self.thread_handle.is_some());
 262                 self.join_thread()
 263         }
 264
 265         /// Stop `BackgroundProcessor`'s thread, returning any error that occurred while persisting
 266         /// [`ChannelManager`].
 267         ///
 268         /// # Panics
 269         ///
 270         /// This function panics if the background thread has panicked such as while persisting or
 271         /// handling events.
 272         ///
 273         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 274         pub fn stop(mut self) -> Result<(), std::io::Error> {
 275                 assert!(self.thread_handle.is_some());
 276                 self.stop_and_join_thread()
 277         }
 278
 279         fn stop_and_join_thread(&mut self) -> Result<(), std::io::Error> {
 280                 self.stop_thread.store(true, Ordering::Release);
 281                 self.join_thread()
 282         }
 283
 284         fn join_thread(&mut self) -> Result<(), std::io::Error> {
 285                 match self.thread_handle.take() {
 286                         Some(handle) => handle.join().unwrap(),
 287                         None => Ok(()),
 288                 }
 289         }
 290 }
 291
 292 impl Drop for BackgroundProcessor {
 293         fn drop(&mut self) {
 294                 self.stop_and_join_thread().unwrap();
 295         }
 296 }
 297
 298 #[cfg(test)]
 299 mod tests {
 300         use bitcoin::blockdata::block::BlockHeader;
 301         use bitcoin::blockdata::constants::genesis_block;
 302         use bitcoin::blockdata::transaction::{Transaction, TxOut};
 303         use bitcoin::network::constants::Network;
 304         use lightning::chain::{BestBlock, Confirm, chainmonitor};
 305         use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
 306         use lightning::chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager};
 307         use lightning::chain::transaction::OutPoint;
 308         use lightning::get_event_msg;
 309         use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, ChainParameters, ChannelManager, SimpleArcChannelManager};
 310         use lightning::ln::features::InitFeatures;
 311         use lightning::ln::msgs::{ChannelMessageHandler, Init};
 312         use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor, IgnoringMessageHandler};
 313         use lightning::routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
 314         use lightning::util::config::UserConfig;
 315         use lightning::util::events::{Event, MessageSendEventsProvider, MessageSendEvent};
 316         use lightning::util::ser::Writeable;
 317         use lightning::util::test_utils;
 318         use lightning_persister::FilesystemPersister;
 319         use std::fs;
 320         use std::path::PathBuf;
 321         use std::sync::{Arc, Mutex};
 322         use std::time::Duration;
 323         use super::{BackgroundProcessor, FRESHNESS_TIMER};
 324
 325         const EVENT_DEADLINE: u64 = 5 * FRESHNESS_TIMER;
 326
 327         #[derive(Clone, Eq, Hash, PartialEq)]
 328         struct TestDescriptor{}
 329         impl SocketDescriptor for TestDescriptor {
 330                 fn send_data(&mut self, _data: &[u8], _resume_read: bool) -> usize {
 331                         0
 332                 }
 333
 334                 fn disconnect_socket(&mut self) {}
 335         }
 336
 337         type ChainMonitor = chainmonitor::ChainMonitor<InMemorySigner, Arc<test_utils::TestChainSource>, Arc<test_utils::TestBroadcaster>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>, Arc<FilesystemPersister>>;
 338
 339         struct Node {
 340                 node: Arc<SimpleArcChannelManager<ChainMonitor, test_utils::TestBroadcaster, test_utils::TestFeeEstimator, test_utils::TestLogger>>,
 341                 net_graph_msg_handler: Option<Arc<NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>>>,
 342                 peer_manager: Arc<PeerManager<TestDescriptor, Arc<test_utils::TestChannelMessageHandler>, Arc<test_utils::TestRoutingMessageHandler>, Arc<test_utils::TestLogger>, IgnoringMessageHandler>>,
 343                 chain_monitor: Arc<ChainMonitor>,
 344                 persister: Arc<FilesystemPersister>,
 345                 tx_broadcaster: Arc<test_utils::TestBroadcaster>,
 346                 logger: Arc<test_utils::TestLogger>,
 347                 best_block: BestBlock,
 348         }
 349
 350         impl Drop for Node {
 351                 fn drop(&mut self) {
 352                         let data_dir = self.persister.get_data_dir();
 353                         match fs::remove_dir_all(data_dir.clone()) {
 354                                 Err(e) => println!("Failed to remove test persister directory {}: {}", data_dir, e),
 355                                 _ => {}
 356                         }
 357                 }
 358         }
 359
 360         fn get_full_filepath(filepath: String, filename: String) -> String {
 361                 let mut path = PathBuf::from(filepath);
 362                 path.push(filename);
 363                 path.to_str().unwrap().to_string()
 364         }
 365
 366         fn create_nodes(num_nodes: usize, persist_dir: String) -> Vec<Node> {
 367                 let mut nodes = Vec::new();
 368                 for i in 0..num_nodes {
 369                         let tx_broadcaster = Arc::new(test_utils::TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
 370                         let fee_estimator = Arc::new(test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) });
 371                         let chain_source = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
 372                         let logger = Arc::new(test_utils::TestLogger::with_id(format!("node {}", i)));
 373                         let persister = Arc::new(FilesystemPersister::new(format!("{}_persister_{}", persist_dir, i)));
 374                         let seed = [i as u8; 32];
 375                         let network = Network::Testnet;
 376                         let genesis_block = genesis_block(network);
 377                         let now = Duration::from_secs(genesis_block.header.time as u64);
 378                         let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_nanos()));
 379                         let chain_monitor = Arc::new(chainmonitor::ChainMonitor::new(Some(chain_source.clone()), tx_broadcaster.clone(), logger.clone(), fee_estimator.clone(), persister.clone()));
 380                         let best_block = BestBlock::from_genesis(network);
 381                         let params = ChainParameters { network, best_block };
 382                         let manager = Arc::new(ChannelManager::new(fee_estimator.clone(), chain_monitor.clone(), tx_broadcaster.clone(), logger.clone(), keys_manager.clone(), UserConfig::default(), params));
 383                         let network_graph = NetworkGraph::new(genesis_block.header.block_hash());
 384                         let net_graph_msg_handler = Some(Arc::new(NetGraphMsgHandler::new(network_graph, Some(chain_source.clone()), logger.clone())));
 385                         let msg_handler = MessageHandler { chan_handler: Arc::new(test_utils::TestChannelMessageHandler::new()), route_handler: Arc::new(test_utils::TestRoutingMessageHandler::new() )};
 386                         let peer_manager = Arc::new(PeerManager::new(msg_handler, keys_manager.get_node_secret(), &seed, logger.clone(), IgnoringMessageHandler{}));
 387                         let node = Node { node: manager, net_graph_msg_handler, peer_manager, chain_monitor, persister, tx_broadcaster, logger, best_block };
 388                         nodes.push(node);
 389                 }
 390
 391                 for i in 0..num_nodes {
 392                         for j in (i+1)..num_nodes {
 393                                 nodes[i].node.peer_connected(&nodes[j].node.get_our_node_id(), &Init { features: InitFeatures::known() });
 394                                 nodes[j].node.peer_connected(&nodes[i].node.get_our_node_id(), &Init { features: InitFeatures::known() });
 395                         }
 396                 }
 397
 398                 nodes
 399         }
 400
 401         macro_rules! open_channel {
 402                 ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
 403                         begin_open_channel!($node_a, $node_b, $channel_value);
 404                         let events = $node_a.node.get_and_clear_pending_events();
 405                         assert_eq!(events.len(), 1);
 406                         let (temporary_channel_id, tx) = handle_funding_generation_ready!(&events[0], $channel_value);
 407                         end_open_channel!($node_a, $node_b, temporary_channel_id, tx);
 408                         tx
 409                 }}
 410         }
 411
 412         macro_rules! begin_open_channel {
 413                 ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
 414                         $node_a.node.create_channel($node_b.node.get_our_node_id(), $channel_value, 100, 42, None).unwrap();
 415                         $node_b.node.handle_open_channel(&$node_a.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_a, MessageSendEvent::SendOpenChannel, $node_b.node.get_our_node_id()));
 416                         $node_a.node.handle_accept_channel(&$node_b.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_b, MessageSendEvent::SendAcceptChannel, $node_a.node.get_our_node_id()));
 417                 }}
 418         }
 419
 420         macro_rules! handle_funding_generation_ready {
 421                 ($event: expr, $channel_value: expr) => {{
 422                         match $event {
 423                                 &Event::FundingGenerationReady { temporary_channel_id, channel_value_satoshis, ref output_script, user_channel_id } => {
 424                                         assert_eq!(channel_value_satoshis, $channel_value);
 425                                         assert_eq!(user_channel_id, 42);
 426
 427                                         let tx = Transaction { version: 1 as i32, lock_time: 0, input: Vec::new(), output: vec![TxOut {
 428                                                 value: channel_value_satoshis, script_pubkey: output_script.clone(),
 429                                         }]};
 430                                         (temporary_channel_id, tx)
 431                                 },
 432                                 _ => panic!("Unexpected event"),
 433                         }
 434                 }}
 435         }
 436
 437         macro_rules! end_open_channel {
 438                 ($node_a: expr, $node_b: expr, $temporary_channel_id: expr, $tx: expr) => {{
 439                         $node_a.node.funding_transaction_generated(&$temporary_channel_id, $tx.clone()).unwrap();
 440                         $node_b.node.handle_funding_created(&$node_a.node.get_our_node_id(), &get_event_msg!($node_a, MessageSendEvent::SendFundingCreated, $node_b.node.get_our_node_id()));
 441                         $node_a.node.handle_funding_signed(&$node_b.node.get_our_node_id(), &get_event_msg!($node_b, MessageSendEvent::SendFundingSigned, $node_a.node.get_our_node_id()));
 442                 }}
 443         }
 444
 445         fn confirm_transaction_depth(node: &mut Node, tx: &Transaction, depth: u32) {
 446                 for i in 1..=depth {
 447                         let prev_blockhash = node.best_block.block_hash();
 448                         let height = node.best_block.height() + 1;
 449                         let header = BlockHeader { version: 0x20000000, prev_blockhash, merkle_root: Default::default(), time: height, bits: 42, nonce: 42 };
 450                         let txdata = vec![(0, tx)];
 451                         node.best_block = BestBlock::new(header.block_hash(), height);
 452                         match i {
 453                                 1 => {
 454                                         node.node.transactions_confirmed(&header, &txdata, height);
 455                                         node.chain_monitor.transactions_confirmed(&header, &txdata, height);
 456                                 },
 457                                 x if x == depth => {
 458                                         node.node.best_block_updated(&header, height);
 459                                         node.chain_monitor.best_block_updated(&header, height);
 460                                 },
 461                                 _ => {},
 462                         }
 463                 }
 464         }
 465         fn confirm_transaction(node: &mut Node, tx: &Transaction) {
 466                 confirm_transaction_depth(node, tx, ANTI_REORG_DELAY);
 467         }
 468
 469         #[test]
 470         fn test_background_processor() {
 471                 // Test that when a new channel is created, the ChannelManager needs to be re-persisted with
 472                 // updates. Also test that when new updates are available, the manager signals that it needs
 473                 // re-persistence and is successfully re-persisted.
 474                 let nodes = create_nodes(2, "test_background_processor".to_string());
 475
 476                 // Go through the channel creation process so that each node has something to persist. Since
 477                 // open_channel consumes events, it must complete before starting BackgroundProcessor to
 478                 // avoid a race with processing events.
 479                 let tx = open_channel!(nodes[0], nodes[1], 100000);
 480
 481                 // Initiate the background processors to watch each node.
 482                 let data_dir = nodes[0].persister.get_data_dir();
 483                 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);
 484                 let event_handler = |_: &_| {};
 485                 let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].net_graph_msg_handler.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 486
 487                 macro_rules! check_persisted_data {
 488                         ($node: expr, $filepath: expr, $expected_bytes: expr) => {
 489                                 match $node.write(&mut $expected_bytes) {
 490                                         Ok(()) => {
 491                                                 loop {
 492                                                         match std::fs::read($filepath) {
 493                                                                 Ok(bytes) => {
 494                                                                         if bytes == $expected_bytes {
 495                                                                                 break
 496                                                                         } else {
 497                                                                                 continue
 498                                                                         }
 499                                                                 },
 500                                                                 Err(_) => continue
 501                                                         }
 502                                                 }
 503                                         },
 504                                         Err(e) => panic!("Unexpected error: {}", e)
 505                                 }
 506                         }
 507                 }
 508
 509                 // Check that the initial channel manager data is persisted as expected.
 510                 let filepath = get_full_filepath("test_background_processor_persister_0".to_string(), "manager".to_string());
 511                 let mut expected_bytes = Vec::new();
 512                 check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
 513                 loop {
 514                         if !nodes[0].node.get_persistence_condvar_value() { break }
 515                 }
 516
 517                 // Force-close the channel.
 518                 nodes[0].node.force_close_channel(&OutPoint { txid: tx.txid(), index: 0 }.to_channel_id()).unwrap();
 519
 520                 // Check that the force-close updates are persisted.
 521                 let mut expected_bytes = Vec::new();
 522                 check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
 523                 loop {
 524                         if !nodes[0].node.get_persistence_condvar_value() { break }
 525                 }
 526
 527                 assert!(bg_processor.stop().is_ok());
 528         }
 529
 530         #[test]
 531         fn test_timer_tick_called() {
 532                 // Test that ChannelManager's and PeerManager's `timer_tick_occurred` is called every
 533                 // `FRESHNESS_TIMER`.
 534                 let nodes = create_nodes(1, "test_timer_tick_called".to_string());
 535                 let data_dir = nodes[0].persister.get_data_dir();
 536                 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);
 537                 let event_handler = |_: &_| {};
 538                 let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].net_graph_msg_handler.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 539                 loop {
 540                         let log_entries = nodes[0].logger.lines.lock().unwrap();
 541                         let desired_log = "Calling ChannelManager's timer_tick_occurred".to_string();
 542                         let second_desired_log = "Calling PeerManager's timer_tick_occurred".to_string();
 543                         if log_entries.get(&("lightning_background_processor".to_string(), desired_log)).is_some() &&
 544                                         log_entries.get(&("lightning_background_processor".to_string(), second_desired_log)).is_some() {
 545                                 break
 546                         }
 547                 }
 548
 549                 assert!(bg_processor.stop().is_ok());
 550         }
 551
 552         #[test]
 553         fn test_persist_error() {
 554                 // Test that if we encounter an error during manager persistence, the thread panics.
 555                 let nodes = create_nodes(2, "test_persist_error".to_string());
 556                 open_channel!(nodes[0], nodes[1], 100000);
 557
 558                 let persister = |_: &_| Err(std::io::Error::new(std::io::ErrorKind::Other, "test"));
 559                 let event_handler = |_: &_| {};
 560                 let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].net_graph_msg_handler.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 561                 match bg_processor.join() {
 562                         Ok(_) => panic!("Expected error persisting manager"),
 563                         Err(e) => {
 564                                 assert_eq!(e.kind(), std::io::ErrorKind::Other);
 565                                 assert_eq!(e.get_ref().unwrap().to_string(), "test");
 566                         },
 567                 }
 568         }
 569
 570         #[test]
 571         fn test_background_event_handling() {
 572                 let mut nodes = create_nodes(2, "test_background_event_handling".to_string());
 573                 let channel_value = 100000;
 574                 let data_dir = nodes[0].persister.get_data_dir();
 575                 let persister = move |node: &_| FilesystemPersister::persist_manager(data_dir.clone(), node);
 576
 577                 // Set up a background event handler for FundingGenerationReady events.
 578                 let (sender, receiver) = std::sync::mpsc::sync_channel(1);
 579                 let event_handler = move |event: &Event| {
 580                         sender.send(handle_funding_generation_ready!(event, channel_value)).unwrap();
 581                 };
 582                 let bg_processor = BackgroundProcessor::start(persister.clone(), event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].net_graph_msg_handler.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 583
 584                 // Open a channel and check that the FundingGenerationReady event was handled.
 585                 begin_open_channel!(nodes[0], nodes[1], channel_value);
 586                 let (temporary_channel_id, funding_tx) = receiver
 587                         .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
 588                         .expect("FundingGenerationReady not handled within deadline");
 589                 end_open_channel!(nodes[0], nodes[1], temporary_channel_id, funding_tx);
 590
 591                 // Confirm the funding transaction.
 592                 confirm_transaction(&mut nodes[0], &funding_tx);
 593                 let as_funding = get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id());
 594                 confirm_transaction(&mut nodes[1], &funding_tx);
 595                 let bs_funding = get_event_msg!(nodes[1], MessageSendEvent::SendFundingLocked, nodes[0].node.get_our_node_id());
 596                 nodes[0].node.handle_funding_locked(&nodes[1].node.get_our_node_id(), &bs_funding);
 597                 let _as_channel_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
 598                 nodes[1].node.handle_funding_locked(&nodes[0].node.get_our_node_id(), &as_funding);
 599                 let _bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
 600
 601                 assert!(bg_processor.stop().is_ok());
 602
 603                 // Set up a background event handler for SpendableOutputs events.
 604                 let (sender, receiver) = std::sync::mpsc::sync_channel(1);
 605                 let event_handler = move |event: &Event| sender.send(event.clone()).unwrap();
 606                 let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].net_graph_msg_handler.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
 607
 608                 // Force close the channel and check that the SpendableOutputs event was handled.
 609                 nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id).unwrap();
 610                 let commitment_tx = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().pop().unwrap();
 611                 confirm_transaction_depth(&mut nodes[0], &commitment_tx, BREAKDOWN_TIMEOUT as u32);
 612                 let event = receiver
 613                         .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
 614                         .expect("SpendableOutputs not handled within deadline");
 615                 match event {
 616                         Event::SpendableOutputs { .. } => {},
 617                         Event::ChannelClosed { .. } => {},
 618                         _ => panic!("Unexpected event: {:?}", event),
 619                 }
 620
 621                 assert!(bg_processor.stop().is_ok());
 622         }
 623 }