_ 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, Persist};
  14 use lightning::chain::keysinterface::{Sign, KeysInterface};
  15 use lightning::ln::channelmanager::ChannelManager;
  16 use lightning::ln::msgs::{ChannelMessageHandler, RoutingMessageHandler};
  17 use lightning::ln::peer_handler::{CustomMessageHandler, PeerManager, SocketDescriptor};
  18 use lightning::routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
  19 use lightning::util::events::{Event, 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 /// * Processing [`Event`]s with a user-provided [`EventHandler`].
  32 /// * Monitoring whether the [`ChannelManager`] needs to be re-persisted to disk, and if so,
  33 ///   writing it to disk/backups by invoking the callback given to it at startup.
  34 ///   [`ChannelManager`] persistence should be done in the background.
  35 /// * Calling [`ChannelManager::timer_tick_occurred`] and [`PeerManager::timer_tick_occurred`]
  36 ///   at the appropriate intervals.
  37 ///
  38 /// It will also call [`PeerManager::process_events`] periodically though this shouldn't be relied
  39 /// upon as doing so may result in high latency.
  40 ///
  41 /// # Note
  42 ///
  43 /// If [`ChannelManager`] persistence fails and the persisted manager becomes out-of-date, then
  44 /// there is a risk of channels force-closing on startup when the manager realizes it's outdated.
  45 /// However, as long as [`ChannelMonitor`] backups are sound, no funds besides those used for
  46 /// unilateral chain closure fees are at risk.
  47 ///
  48 /// [`ChannelMonitor`]: lightning::chain::channelmonitor::ChannelMonitor
  49 /// [`Event`]: lightning::util::events::Event
  50 #[must_use = "BackgroundProcessor will immediately stop on drop. It should be stored until shutdown."]
  51 pub struct BackgroundProcessor {
  52         stop_thread: Arc<AtomicBool>,
  53         thread_handle: Option<JoinHandle<Result<(), std::io::Error>>>,
  54 }
  55
  56 #[cfg(not(test))]
  57 const FRESHNESS_TIMER: u64 = 60;
  58 #[cfg(test)]
  59 const FRESHNESS_TIMER: u64 = 1;
  60
  61 #[cfg(all(not(test), not(debug_assertions)))]
  62 const PING_TIMER: u64 = 5;
  63 /// Signature operations take a lot longer without compiler optimisations.
  64 /// Increasing the ping timer allows for this but slower devices will be disconnected if the
  65 /// timeout is reached.
  66 #[cfg(all(not(test), debug_assertions))]
  67 const PING_TIMER: u64 = 30;
  68 #[cfg(test)]
  69 const PING_TIMER: u64 = 1;
  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<G, A, L>>,
 107         G: Deref<Target = NetworkGraph>,
 108         A: Deref,
 109         L: Deref,
 110 >
 111 where A::Target: chain::Access, L::Target: Logger {
 112         event_handler: E,
 113         net_graph_msg_handler: Option<N>,
 114 }
 115
 116 impl<
 117         E: EventHandler,
 118         N: Deref<Target = NetGraphMsgHandler<G, A, L>>,
 119         G: Deref<Target = NetworkGraph>,
 120         A: Deref,
 121         L: Deref,
 122 > EventHandler for DecoratingEventHandler<E, N, G, A, L>
 123 where A::Target: chain::Access, L::Target: Logger {
 124         fn handle_event(&self, event: &Event) {
 125                 if let Some(event_handler) = &self.net_graph_msg_handler {
 126                         event_handler.handle_event(event);
 127                 }
 128                 self.event_handler.handle_event(event);
 129         }
 130 }
 131
 132 impl BackgroundProcessor {
 133         /// Start a background thread that takes care of responsibilities enumerated in the [top-level
 134         /// documentation].
 135         ///
 136         /// The thread runs indefinitely unless the object is dropped, [`stop`] is called, or
 137         /// `persist_manager` returns an error. In case of an error, the error is retrieved by calling
 138         /// either [`join`] or [`stop`].
 139         ///
 140         /// # Data Persistence
 141         ///
 142         /// `persist_manager` is responsible for writing out the [`ChannelManager`] to disk, and/or
 143         /// uploading to one or more backup services. See [`ChannelManager::write`] for writing out a
 144         /// [`ChannelManager`]. See [`FilesystemPersister::persist_manager`] for Rust-Lightning's
 145         /// provided implementation.
 146         ///
 147         /// Typically, users should either implement [`ChannelManagerPersister`] to never return an
 148         /// error or call [`join`] and handle any error that may arise. For the latter case,
 149         /// `BackgroundProcessor` must be restarted by calling `start` again after handling the error.
 150         ///
 151         /// # Event Handling
 152         ///
 153         /// `event_handler` is responsible for handling events that users should be notified of (e.g.,
 154         /// payment failed). [`BackgroundProcessor`] may decorate the given [`EventHandler`] with common
 155         /// functionality implemented by other handlers.
 156         /// * [`NetGraphMsgHandler`] if given will update the [`NetworkGraph`] based on payment failures.
 157         ///
 158         /// [top-level documentation]: Self
 159         /// [`join`]: Self::join
 160         /// [`stop`]: Self::stop
 161         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 162         /// [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
 163         /// [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
 164         /// [`NetworkGraph`]: lightning::routing::network_graph::NetworkGraph
 165         pub fn start<
 166                 Signer: 'static + Sign,
 167                 CA: 'static + Deref + Send + Sync,
 168                 CF: 'static + Deref + Send + Sync,
 169                 CW: 'static + Deref + Send + Sync,
 170                 T: 'static + Deref + Send + Sync,
 171                 K: 'static + Deref + Send + Sync,
 172                 F: 'static + Deref + Send + Sync,
 173                 G: 'static + Deref<Target = NetworkGraph> + Send + Sync,
 174                 L: 'static + Deref + Send + Sync,
 175                 P: 'static + Deref + Send + Sync,
 176                 Descriptor: 'static + SocketDescriptor + Send + Sync,
 177                 CMH: 'static + Deref + Send + Sync,
 178                 RMH: 'static + Deref + Send + Sync,
 179                 EH: 'static + EventHandler + Send,
 180                 CMP: 'static + Send + ChannelManagerPersister<Signer, CW, T, K, F, L>,
 181                 M: 'static + Deref<Target = ChainMonitor<Signer, CF, T, F, L, P>> + Send + Sync,
 182                 CM: 'static + Deref<Target = ChannelManager<Signer, CW, T, K, F, L>> + Send + Sync,
 183                 NG: 'static + Deref<Target = NetGraphMsgHandler<G, CA, L>> + Send + Sync,
 184                 UMH: 'static + Deref + Send + Sync,
 185                 PM: 'static + Deref<Target = PeerManager<Descriptor, CMH, RMH, L, UMH>> + Send + Sync,
 186         >(
 187                 persister: CMP, event_handler: EH, chain_monitor: M, channel_manager: CM,
 188                 net_graph_msg_handler: Option<NG>, peer_manager: PM, logger: L
 189         ) -> Self
 190         where
 191                 CA::Target: 'static + chain::Access,
 192                 CF::Target: 'static + chain::Filter,
 193                 CW::Target: 'static + chain::Watch<Signer>,
 194                 T::Target: 'static + BroadcasterInterface,
 195                 K::Target: 'static + KeysInterface<Signer = Signer>,
 196                 F::Target: 'static + FeeEstimator,
 197                 L::Target: 'static + Logger,
 198                 P::Target: 'static + Persist<Signer>,
 199                 CMH::Target: 'static + ChannelMessageHandler,
 200                 RMH::Target: 'static + RoutingMessageHandler,
 201                 UMH::Target: 'static + CustomMessageHandler,
 202         {
 203                 let stop_thread = Arc::new(AtomicBool::new(false));
 204                 let stop_thread_clone = stop_thread.clone();
 205                 let handle = thread::spawn(move || -> Result<(), std::io::Error> {
 206                         let event_handler = DecoratingEventHandler { event_handler, net_graph_msg_handler };
 207
 208                         log_trace!(logger, "Calling ChannelManager's timer_tick_occurred on startup");
 209                         channel_manager.timer_tick_occurred();
 210
 211                         let mut last_freshness_call = Instant::now();
 212                         let mut last_ping_call = Instant::now();
 213                         loop {
 214                                 peer_manager.process_events();
 215                                 channel_manager.process_pending_events(&event_handler);
 216                                 chain_monitor.process_pending_events(&event_handler);
 217                                 let updates_available =
 218                                         channel_manager.await_persistable_update_timeout(Duration::from_millis(100));
 219                                 if updates_available {
 220                                         persister.persist_manager(&*channel_manager)?;
 221                                 }
 222                                 // Exit the loop if the background processor was requested to stop.
 223                                 if stop_thread.load(Ordering::Acquire) == true {
 224                                         log_trace!(logger, "Terminating background processor.");
 225                                         return Ok(());
 226                                 }
 227                                 if last_freshness_call.elapsed().as_secs() > FRESHNESS_TIMER {
 228                                         log_trace!(logger, "Calling ChannelManager's timer_tick_occurred");
 229                                         channel_manager.timer_tick_occurred();
 230                                         last_freshness_call = Instant::now();
 231                                 }
 232                                 if last_ping_call.elapsed().as_secs() > PING_TIMER * 2 {
 233                                         // On various platforms, we may be starved of CPU cycles for several reasons.
 234                                         // E.g. on iOS, if we've been in the background, we will be entirely paused.
 235                                         // Similarly, if we're on a desktop platform and the device has been asleep, we
 236                                         // may not get any cycles.
 237                                         // In any case, if we've been entirely paused for more than double our ping
 238                                         // timer, we should have disconnected all sockets by now (and they're probably
 239                                         // dead anyway), so disconnect them by calling `timer_tick_occurred()` twice.
 240                                         log_trace!(logger, "Awoke after more than double our ping timer, disconnecting peers.");
 241                                         peer_manager.disconnect_all_peers();
 242                                         last_ping_call = Instant::now();
 243                                 } else if last_ping_call.elapsed().as_secs() > PING_TIMER {
 244                                         log_trace!(logger, "Calling PeerManager's timer_tick_occurred");
 245                                         peer_manager.timer_tick_occurred();
 246                                         last_ping_call = Instant::now();
 247                                 }
 248                         }
 249                 });
 250                 Self { stop_thread: stop_thread_clone, thread_handle: Some(handle) }
 251         }
 252
 253         /// Join `BackgroundProcessor`'s thread, returning any error that occurred while persisting
 254         /// [`ChannelManager`].
 255         ///
 256         /// # Panics
 257         ///
 258         /// This function panics if the background thread has panicked such as while persisting or
 259         /// handling events.
 260         ///
 261         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 262         pub fn join(mut self) -> Result<(), std::io::Error> {
 263                 assert!(self.thread_handle.is_some());
 264                 self.join_thread()
 265         }
 266
 267         /// Stop `BackgroundProcessor`'s thread, returning any error that occurred while persisting
 268         /// [`ChannelManager`].
 269         ///
 270         /// # Panics
 271         ///
 272         /// This function panics if the background thread has panicked such as while persisting or
 273         /// handling events.
 274         ///
 275         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 276         pub fn stop(mut self) -> Result<(), std::io::Error> {
 277                 assert!(self.thread_handle.is_some());
 278                 self.stop_and_join_thread()
 279         }
 280
 281         fn stop_and_join_thread(&mut self) -> Result<(), std::io::Error> {
 282                 self.stop_thread.store(true, Ordering::Release);
 283                 self.join_thread()
 284         }
 285
 286         fn join_thread(&mut self) -> Result<(), std::io::Error> {
 287                 match self.thread_handle.take() {
 288                         Some(handle) => handle.join().unwrap(),
 289                         None => Ok(()),
 290                 }
 291         }
 292 }
 293
 294 impl Drop for BackgroundProcessor {
 295         fn drop(&mut self) {
 296                 self.stop_and_join_thread().unwrap();
 297         }
 298 }
 299
 300 #[cfg(test)]
 301 mod tests {
 302         use bitcoin::blockdata::block::BlockHeader;
 303         use bitcoin::blockdata::constants::genesis_block;
 304         use bitcoin::blockdata::transaction::{Transaction, TxOut};
 305         use bitcoin::network::constants::Network;
 306         use lightning::chain::{BestBlock, Confirm, chainmonitor};
 307         use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
 308         use lightning::chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager};
 309         use lightning::chain::transaction::OutPoint;
 310         use lightning::get_event_msg;
 311         use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, ChainParameters, ChannelManager, SimpleArcChannelManager};
 312         use lightning::ln::features::InitFeatures;
 313         use lightning::ln::msgs::{ChannelMessageHandler, Init};
 314         use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor, IgnoringMessageHandler};
 315         use lightning::routing::scorer::Scorer;
 316         use lightning::routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
 317         use lightning::util::config::UserConfig;
 318         use lightning::util::events::{Event, MessageSendEventsProvider, MessageSendEvent};
 319         use lightning::util::ser::Writeable;
 320         use lightning::util::test_utils;
 321         use lightning_invoice::payment::{InvoicePayer, RetryAttempts};
 322         use lightning_invoice::utils::DefaultRouter;
 323         use lightning_persister::FilesystemPersister;
 324         use std::fs;
 325         use std::path::PathBuf;
 326         use std::sync::{Arc, Mutex};
 327         use std::time::Duration;
 328         use super::{BackgroundProcessor, FRESHNESS_TIMER};
 329
 330         const EVENT_DEADLINE: u64 = 5 * FRESHNESS_TIMER;
 331
 332         #[derive(Clone, Eq, Hash, PartialEq)]
 333         struct TestDescriptor{}
 334         impl SocketDescriptor for TestDescriptor {
 335                 fn send_data(&mut self, _data: &[u8], _resume_read: bool) -> usize {
 336                         0
 337                 }
 338
 339                 fn disconnect_socket(&mut self) {}
 340         }
 341
 342         type ChainMonitor = chainmonitor::ChainMonitor<InMemorySigner, Arc<test_utils::TestChainSource>, Arc<test_utils::TestBroadcaster>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>, Arc<FilesystemPersister>>;
 343
 344         struct Node {
 345                 node: Arc<SimpleArcChannelManager<ChainMonitor, test_utils::TestBroadcaster, test_utils::TestFeeEstimator, test_utils::TestLogger>>,
 346                 net_graph_msg_handler: Option<Arc<NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>>>,
 347                 peer_manager: Arc<PeerManager<TestDescriptor, Arc<test_utils::TestChannelMessageHandler>, Arc<test_utils::TestRoutingMessageHandler>, Arc<test_utils::TestLogger>, IgnoringMessageHandler>>,
 348                 chain_monitor: Arc<ChainMonitor>,
 349                 persister: Arc<FilesystemPersister>,
 350                 tx_broadcaster: Arc<test_utils::TestBroadcaster>,
 351                 network_graph: Arc<NetworkGraph>,
 352                 logger: Arc<test_utils::TestLogger>,
 353                 best_block: BestBlock,
 354         }
 355
 356         impl Drop for Node {
 357                 fn drop(&mut self) {
 358                         let data_dir = self.persister.get_data_dir();
 359                         match fs::remove_dir_all(data_dir.clone()) {
 360                                 Err(e) => println!("Failed to remove test persister directory {}: {}", data_dir, e),
 361                                 _ => {}
 362                         }
 363                 }
 364         }
 365
 366         fn get_full_filepath(filepath: String, filename: String) -> String {
 367                 let mut path = PathBuf::from(filepath);
 368                 path.push(filename);
 369                 path.to_str().unwrap().to_string()
 370         }
 371
 372         fn create_nodes(num_nodes: usize, persist_dir: String) -> Vec<Node> {
 373                 let mut nodes = Vec::new();
 374                 for i in 0..num_nodes {
 375                         let tx_broadcaster = Arc::new(test_utils::TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
 376                         let fee_estimator = Arc::new(test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) });
 377                         let chain_source = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
 378                         let logger = Arc::new(test_utils::TestLogger::with_id(format!("node {}", i)));
 379                         let persister = Arc::new(FilesystemPersister::new(format!("{}_persister_{}", persist_dir, i)));
 380                         let seed = [i as u8; 32];
 381                         let network = Network::Testnet;
 382                         let genesis_block = genesis_block(network);
 383                         let now = Duration::from_secs(genesis_block.header.time as u64);
 384                         let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_nanos()));
 385                         let chain_monitor = Arc::new(chainmonitor::ChainMonitor::new(Some(chain_source.clone()), tx_broadcaster.clone(), logger.clone(), fee_estimator.clone(), persister.clone()));
 386                         let best_block = BestBlock::from_genesis(network);
 387                         let params = ChainParameters { network, best_block };
 388                         let manager = Arc::new(ChannelManager::new(fee_estimator.clone(), chain_monitor.clone(), tx_broadcaster.clone(), logger.clone(), keys_manager.clone(), UserConfig::default(), params));
 389                         let network_graph = Arc::new(NetworkGraph::new(genesis_block.header.block_hash()));
 390                         let net_graph_msg_handler = Some(Arc::new(NetGraphMsgHandler::new(network_graph.clone(), Some(chain_source.clone()), logger.clone())));
 391                         let msg_handler = MessageHandler { chan_handler: Arc::new(test_utils::TestChannelMessageHandler::new()), route_handler: Arc::new(test_utils::TestRoutingMessageHandler::new() )};
 392                         let peer_manager = Arc::new(PeerManager::new(msg_handler, keys_manager.get_node_secret(), &seed, logger.clone(), IgnoringMessageHandler{}));
 393                         let node = Node { node: manager, net_graph_msg_handler, peer_manager, chain_monitor, persister, tx_broadcaster, network_graph, logger, best_block };
 394                         nodes.push(node);
 395                 }
 396
 397                 for i in 0..num_nodes {
 398                         for j in (i+1)..num_nodes {
 399                                 nodes[i].node.peer_connected(&nodes[j].node.get_our_node_id(), &Init { features: InitFeatures::known() });
 400                                 nodes[j].node.peer_connected(&nodes[i].node.get_our_node_id(), &Init { features: InitFeatures::known() });
 401                         }
 402                 }
 403
 404                 nodes
 405         }
 406
 407         macro_rules! open_channel {
 408                 ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
 409                         begin_open_channel!($node_a, $node_b, $channel_value);
 410                         let events = $node_a.node.get_and_clear_pending_events();
 411                         assert_eq!(events.len(), 1);
 412                         let (temporary_channel_id, tx) = handle_funding_generation_ready!(&events[0], $channel_value);
 413                         end_open_channel!($node_a, $node_b, temporary_channel_id, tx);
 414                         tx
 415                 }}
 416         }
 417
 418         macro_rules! begin_open_channel {
 419                 ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
 420                         $node_a.node.create_channel($node_b.node.get_our_node_id(), $channel_value, 100, 42, None).unwrap();
 421                         $node_b.node.handle_open_channel(&$node_a.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_a, MessageSendEvent::SendOpenChannel, $node_b.node.get_our_node_id()));
 422                         $node_a.node.handle_accept_channel(&$node_b.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_b, MessageSendEvent::SendAcceptChannel, $node_a.node.get_our_node_id()));
 423                 }}
 424         }
 425
 426         macro_rules! handle_funding_generation_ready {
 427                 ($event: expr, $channel_value: expr) => {{
 428                         match $event {
 429                                 &Event::FundingGenerationReady { temporary_channel_id, channel_value_satoshis, ref output_script, user_channel_id } => {
 430                                         assert_eq!(channel_value_satoshis, $channel_value);
 431                                         assert_eq!(user_channel_id, 42);
 432
 433                                         let tx = Transaction { version: 1 as i32, lock_time: 0, input: Vec::new(), output: vec![TxOut {
 434                                                 value: channel_value_satoshis, script_pubkey: output_script.clone(),
 435                                         }]};
 436                                         (temporary_channel_id, tx)
 437                                 },
 438                                 _ => panic!("Unexpected event"),
 439                         }
 440                 }}
 441         }
 442
 443         macro_rules! end_open_channel {
 444                 ($node_a: expr, $node_b: expr, $temporary_channel_id: expr, $tx: expr) => {{
 445                         $node_a.node.funding_transaction_generated(&$temporary_channel_id, $tx.clone()).unwrap();
 446                         $node_b.node.handle_funding_created(&$node_a.node.get_our_node_id(), &get_event_msg!($node_a, MessageSendEvent::SendFundingCreated, $node_b.node.get_our_node_id()));
 447                         $node_a.node.handle_funding_signed(&$node_b.node.get_our_node_id(), &get_event_msg!($node_b, MessageSendEvent::SendFundingSigned, $node_a.node.get_our_node_id()));
 448                 }}
 449         }
 450
 451         fn confirm_transaction_depth(node: &mut Node, tx: &Transaction, depth: u32) {
 452                 for i in 1..=depth {
 453                         let prev_blockhash = node.best_block.block_hash();
 454                         let height = node.best_block.height() + 1;
 455                         let header = BlockHeader { version: 0x20000000, prev_blockhash, merkle_root: Default::default(), time: height, bits: 42, nonce: 42 };
 456                         let txdata = vec![(0, tx)];
 457                         node.best_block = BestBlock::new(header.block_hash(), height);
 458                         match i {
 459                                 1 => {
 460                                         node.node.transactions_confirmed(&header, &txdata, height);
 461                                         node.chain_monitor.transactions_confirmed(&header, &txdata, height);
 462                                 },
 463                                 x if x == depth => {
 464                                         node.node.best_block_updated(&header, height);
 465                                         node.chain_monitor.best_block_updated(&header, height);
 466                                 },
 467                                 _ => {},
 468                         }
 469                 }
 470         }
 471         fn confirm_transaction(node: &mut Node, tx: &Transaction) {
 472                 confirm_transaction_depth(node, tx, ANTI_REORG_DELAY);
 473         }
 474
 475         #[test]
 476         fn test_background_processor() {
 477                 // Test that when a new channel is created, the ChannelManager needs to be re-persisted with
 478                 // updates. Also test that when new updates are available, the manager signals that it needs
 479                 // re-persistence and is successfully re-persisted.
 480                 let nodes = create_nodes(2, "test_background_processor".to_string());
 481
 482                 // Go through the channel creation process so that each node has something to persist. Since
 483                 // open_channel consumes events, it must complete before starting BackgroundProcessor to
 484                 // avoid a race with processing events.
 485                 let tx = open_channel!(nodes[0], nodes[1], 100000);
 486
 487                 // Initiate the background processors to watch each node.
 488                 let data_dir = nodes[0].persister.get_data_dir();
 489                 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);
 490                 let event_handler = |_: &_| {};
 491                 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());
 492
 493                 macro_rules! check_persisted_data {
 494                         ($node: expr, $filepath: expr, $expected_bytes: expr) => {
 495                                 match $node.write(&mut $expected_bytes) {
 496                                         Ok(()) => {
 497                                                 loop {
 498                                                         match std::fs::read($filepath) {
 499                                                                 Ok(bytes) => {
 500                                                                         if bytes == $expected_bytes {
 501                                                                                 break
 502                                                                         } else {
 503                                                                                 continue
 504                                                                         }
 505                                                                 },
 506                                                                 Err(_) => continue
 507                                                         }
 508                                                 }
 509                                         },
 510                                         Err(e) => panic!("Unexpected error: {}", e)
 511                                 }
 512                         }
 513                 }
 514
 515                 // Check that the initial channel manager data is persisted as expected.
 516                 let filepath = get_full_filepath("test_background_processor_persister_0".to_string(), "manager".to_string());
 517                 let mut expected_bytes = Vec::new();
 518                 check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
 519                 loop {
 520                         if !nodes[0].node.get_persistence_condvar_value() { break }
 521                 }
 522
 523                 // Force-close the channel.
 524                 nodes[0].node.force_close_channel(&OutPoint { txid: tx.txid(), index: 0 }.to_channel_id()).unwrap();
 525
 526                 // Check that the force-close updates are persisted.
 527                 let mut expected_bytes = Vec::new();
 528                 check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
 529                 loop {
 530                         if !nodes[0].node.get_persistence_condvar_value() { break }
 531                 }
 532
 533                 assert!(bg_processor.stop().is_ok());
 534         }
 535
 536         #[test]
 537         fn test_timer_tick_called() {
 538                 // Test that ChannelManager's and PeerManager's `timer_tick_occurred` is called every
 539                 // `FRESHNESS_TIMER`.
 540                 let nodes = create_nodes(1, "test_timer_tick_called".to_string());
 541                 let data_dir = nodes[0].persister.get_data_dir();
 542                 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);
 543                 let event_handler = |_: &_| {};
 544                 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());
 545                 loop {
 546                         let log_entries = nodes[0].logger.lines.lock().unwrap();
 547                         let desired_log = "Calling ChannelManager's timer_tick_occurred".to_string();
 548                         let second_desired_log = "Calling PeerManager's timer_tick_occurred".to_string();
 549                         if log_entries.get(&("lightning_background_processor".to_string(), desired_log)).is_some() &&
 550                                         log_entries.get(&("lightning_background_processor".to_string(), second_desired_log)).is_some() {
 551                                 break
 552                         }
 553                 }
 554
 555                 assert!(bg_processor.stop().is_ok());
 556         }
 557
 558         #[test]
 559         fn test_persist_error() {
 560                 // Test that if we encounter an error during manager persistence, the thread panics.
 561                 let nodes = create_nodes(2, "test_persist_error".to_string());
 562                 open_channel!(nodes[0], nodes[1], 100000);
 563
 564                 let persister = |_: &_| Err(std::io::Error::new(std::io::ErrorKind::Other, "test"));
 565                 let event_handler = |_: &_| {};
 566                 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());
 567                 match bg_processor.join() {
 568                         Ok(_) => panic!("Expected error persisting manager"),
 569                         Err(e) => {
 570                                 assert_eq!(e.kind(), std::io::ErrorKind::Other);
 571                                 assert_eq!(e.get_ref().unwrap().to_string(), "test");
 572                         },
 573                 }
 574         }
 575
 576         #[test]
 577         fn test_background_event_handling() {
 578                 let mut nodes = create_nodes(2, "test_background_event_handling".to_string());
 579                 let channel_value = 100000;
 580                 let data_dir = nodes[0].persister.get_data_dir();
 581                 let persister = move |node: &_| FilesystemPersister::persist_manager(data_dir.clone(), node);
 582
 583                 // Set up a background event handler for FundingGenerationReady events.
 584                 let (sender, receiver) = std::sync::mpsc::sync_channel(1);
 585                 let event_handler = move |event: &Event| {
 586                         sender.send(handle_funding_generation_ready!(event, channel_value)).unwrap();
 587                 };
 588                 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());
 589
 590                 // Open a channel and check that the FundingGenerationReady event was handled.
 591                 begin_open_channel!(nodes[0], nodes[1], channel_value);
 592                 let (temporary_channel_id, funding_tx) = receiver
 593                         .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
 594                         .expect("FundingGenerationReady not handled within deadline");
 595                 end_open_channel!(nodes[0], nodes[1], temporary_channel_id, funding_tx);
 596
 597                 // Confirm the funding transaction.
 598                 confirm_transaction(&mut nodes[0], &funding_tx);
 599                 let as_funding = get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id());
 600                 confirm_transaction(&mut nodes[1], &funding_tx);
 601                 let bs_funding = get_event_msg!(nodes[1], MessageSendEvent::SendFundingLocked, nodes[0].node.get_our_node_id());
 602                 nodes[0].node.handle_funding_locked(&nodes[1].node.get_our_node_id(), &bs_funding);
 603                 let _as_channel_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
 604                 nodes[1].node.handle_funding_locked(&nodes[0].node.get_our_node_id(), &as_funding);
 605                 let _bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
 606
 607                 assert!(bg_processor.stop().is_ok());
 608
 609                 // Set up a background event handler for SpendableOutputs events.
 610                 let (sender, receiver) = std::sync::mpsc::sync_channel(1);
 611                 let event_handler = move |event: &Event| sender.send(event.clone()).unwrap();
 612                 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());
 613
 614                 // Force close the channel and check that the SpendableOutputs event was handled.
 615                 nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id).unwrap();
 616                 let commitment_tx = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().pop().unwrap();
 617                 confirm_transaction_depth(&mut nodes[0], &commitment_tx, BREAKDOWN_TIMEOUT as u32);
 618                 let event = receiver
 619                         .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
 620                         .expect("SpendableOutputs not handled within deadline");
 621                 match event {
 622                         Event::SpendableOutputs { .. } => {},
 623                         Event::ChannelClosed { .. } => {},
 624                         _ => panic!("Unexpected event: {:?}", event),
 625                 }
 626
 627                 assert!(bg_processor.stop().is_ok());
 628         }
 629
 630         #[test]
 631         fn test_invoice_payer() {
 632                 let nodes = create_nodes(2, "test_invoice_payer".to_string());
 633
 634                 // Initiate the background processors to watch each node.
 635                 let data_dir = nodes[0].persister.get_data_dir();
 636                 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);
 637                 let router = DefaultRouter::new(Arc::clone(&nodes[0].network_graph), Arc::clone(&nodes[0].logger));
 638                 let scorer = Arc::new(Mutex::new(Scorer::default()));
 639                 let invoice_payer = Arc::new(InvoicePayer::new(Arc::clone(&nodes[0].node), router, scorer, Arc::clone(&nodes[0].logger), |_: &_| {}, RetryAttempts(2)));
 640                 let event_handler = Arc::clone(&invoice_payer);
 641                 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());
 642                 assert!(bg_processor.stop().is_ok());
 643         }
 644 }