Merge pull request #1031 from p2pderivatives/dlc-version-generic
[rust-lightning] / 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::util::events::{EventHandler, EventsProvider};
21 use lightning::util::logger::Logger;
22 use std::sync::Arc;
23 use std::sync::atomic::{AtomicBool, Ordering};
24 use std::thread;
25 use std::thread::JoinHandle;
26 use std::time::{Duration, Instant};
27 use std::ops::Deref;
28
29 /// BackgroundProcessor takes care of tasks that (1) need to happen periodically to keep
30 /// Rust-Lightning running properly, and (2) either can or should be run in the background. Its
31 /// responsibilities are:
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
36 ///   `PeerManager::timer_tick_occurred()` every minute (can be done in the
37 ///   background).
38 ///
39 /// Note that if ChannelManager persistence fails and the persisted manager becomes out-of-date,
40 /// then there is a risk of channels force-closing on startup when the manager realizes it's
41 /// outdated. However, as long as `ChannelMonitor` backups are sound, no funds besides those used
42 /// for unilateral chain closure fees are at risk.
43 #[must_use = "BackgroundProcessor will immediately stop on drop. It should be stored until shutdown."]
44 pub struct BackgroundProcessor {
45         stop_thread: Arc<AtomicBool>,
46         thread_handle: Option<JoinHandle<Result<(), std::io::Error>>>,
47 }
48
49 #[cfg(not(test))]
50 const FRESHNESS_TIMER: u64 = 60;
51 #[cfg(test)]
52 const FRESHNESS_TIMER: u64 = 1;
53
54 #[cfg(not(debug_assertions))]
55 const PING_TIMER: u64 = 5;
56 /// Signature operations take a lot longer without compiler optimisations.
57 /// Increasing the ping timer allows for this but slower devices will be disconnected if the
58 /// timeout is reached.
59 #[cfg(debug_assertions)]
60 const PING_TIMER: u64 = 30;
61
62 /// Trait which handles persisting a [`ChannelManager`] to disk.
63 ///
64 /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
65 pub trait ChannelManagerPersister<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
66 where
67         M::Target: 'static + chain::Watch<Signer>,
68         T::Target: 'static + BroadcasterInterface,
69         K::Target: 'static + KeysInterface<Signer = Signer>,
70         F::Target: 'static + FeeEstimator,
71         L::Target: 'static + Logger,
72 {
73         /// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed
74         /// (which will cause the [`BackgroundProcessor`] which called this method to exit.
75         ///
76         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
77         fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>;
78 }
79
80 impl<Fun, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
81 ChannelManagerPersister<Signer, M, T, K, F, L> for Fun where
82         M::Target: 'static + chain::Watch<Signer>,
83         T::Target: 'static + BroadcasterInterface,
84         K::Target: 'static + KeysInterface<Signer = Signer>,
85         F::Target: 'static + FeeEstimator,
86         L::Target: 'static + Logger,
87         Fun: Fn(&ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>,
88 {
89         fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error> {
90                 self(channel_manager)
91         }
92 }
93
94 impl BackgroundProcessor {
95         /// Start a background thread that takes care of responsibilities enumerated in the [top-level
96         /// documentation].
97         ///
98         /// The thread runs indefinitely unless the object is dropped, [`stop`] is called, or
99         /// `persist_manager` returns an error. In case of an error, the error is retrieved by calling
100         /// either [`join`] or [`stop`].
101         ///
102         /// Typically, users should either implement [`ChannelManagerPersister`] to never return an
103         /// error or call [`join`] and handle any error that may arise. For the latter case, the
104         /// `BackgroundProcessor` must be restarted by calling `start` again after handling the error.
105         ///
106         /// `persist_manager` is responsible for writing out the [`ChannelManager`] to disk, and/or
107         /// uploading to one or more backup services. See [`ChannelManager::write`] for writing out a
108         /// [`ChannelManager`]. See [`FilesystemPersister::persist_manager`] for Rust-Lightning's
109         /// provided implementation.
110         ///
111         /// [top-level documentation]: Self
112         /// [`join`]: Self::join
113         /// [`stop`]: Self::stop
114         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
115         /// [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
116         /// [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
117         pub fn start<
118                 Signer: 'static + Sign,
119                 CF: 'static + Deref + Send + Sync,
120                 CW: 'static + Deref + Send + Sync,
121                 T: 'static + Deref + Send + Sync,
122                 K: 'static + Deref + Send + Sync,
123                 F: 'static + Deref + Send + Sync,
124                 L: 'static + Deref + Send + Sync,
125                 P: 'static + Deref + Send + Sync,
126                 Descriptor: 'static + SocketDescriptor + Send + Sync,
127                 CMH: 'static + Deref + Send + Sync,
128                 RMH: 'static + Deref + Send + Sync,
129                 EH: 'static + EventHandler + Send + Sync,
130                 CMP: 'static + Send + ChannelManagerPersister<Signer, CW, T, K, F, L>,
131                 M: 'static + Deref<Target = ChainMonitor<Signer, CF, T, F, L, P>> + Send + Sync,
132                 CM: 'static + Deref<Target = ChannelManager<Signer, CW, T, K, F, L>> + Send + Sync,
133                 UMH: 'static + Deref + Send + Sync,
134                 PM: 'static + Deref<Target = PeerManager<Descriptor, CMH, RMH, L, UMH>> + Send + Sync,
135         >
136         (persister: CMP, event_handler: EH, chain_monitor: M, channel_manager: CM, peer_manager: PM, logger: L) -> Self
137         where
138                 CF::Target: 'static + chain::Filter,
139                 CW::Target: 'static + chain::Watch<Signer>,
140                 T::Target: 'static + BroadcasterInterface,
141                 K::Target: 'static + KeysInterface<Signer = Signer>,
142                 F::Target: 'static + FeeEstimator,
143                 L::Target: 'static + Logger,
144                 P::Target: 'static + channelmonitor::Persist<Signer>,
145                 CMH::Target: 'static + ChannelMessageHandler,
146                 RMH::Target: 'static + RoutingMessageHandler,
147                 UMH::Target: 'static + CustomMessageHandler,
148         {
149                 let stop_thread = Arc::new(AtomicBool::new(false));
150                 let stop_thread_clone = stop_thread.clone();
151                 let handle = thread::spawn(move || -> Result<(), std::io::Error> {
152                         log_trace!(logger, "Calling ChannelManager's timer_tick_occurred on startup");
153                         channel_manager.timer_tick_occurred();
154
155                         let mut last_freshness_call = Instant::now();
156                         let mut last_ping_call = Instant::now();
157                         loop {
158                                 peer_manager.process_events();
159                                 channel_manager.process_pending_events(&event_handler);
160                                 chain_monitor.process_pending_events(&event_handler);
161                                 let updates_available =
162                                         channel_manager.await_persistable_update_timeout(Duration::from_millis(100));
163                                 if updates_available {
164                                         persister.persist_manager(&*channel_manager)?;
165                                 }
166                                 // Exit the loop if the background processor was requested to stop.
167                                 if stop_thread.load(Ordering::Acquire) == true {
168                                         log_trace!(logger, "Terminating background processor.");
169                                         return Ok(());
170                                 }
171                                 if last_freshness_call.elapsed().as_secs() > FRESHNESS_TIMER {
172                                         log_trace!(logger, "Calling ChannelManager's timer_tick_occurred");
173                                         channel_manager.timer_tick_occurred();
174                                         last_freshness_call = Instant::now();
175                                 }
176                                 if last_ping_call.elapsed().as_secs() > PING_TIMER * 2 {
177                                         // On various platforms, we may be starved of CPU cycles for several reasons.
178                                         // E.g. on iOS, if we've been in the background, we will be entirely paused.
179                                         // Similarly, if we're on a desktop platform and the device has been asleep, we
180                                         // may not get any cycles.
181                                         // In any case, if we've been entirely paused for more than double our ping
182                                         // timer, we should have disconnected all sockets by now (and they're probably
183                                         // dead anyway), so disconnect them by calling `timer_tick_occurred()` twice.
184                                         log_trace!(logger, "Awoke after more than double our ping timer, disconnecting peers.");
185                                         peer_manager.timer_tick_occurred();
186                                         peer_manager.timer_tick_occurred();
187                                         last_ping_call = Instant::now();
188                                 } else if last_ping_call.elapsed().as_secs() > PING_TIMER {
189                                         log_trace!(logger, "Calling PeerManager's timer_tick_occurred");
190                                         peer_manager.timer_tick_occurred();
191                                         last_ping_call = Instant::now();
192                                 }
193                         }
194                 });
195                 Self { stop_thread: stop_thread_clone, thread_handle: Some(handle) }
196         }
197
198         /// Join `BackgroundProcessor`'s thread, returning any error that occurred while persisting
199         /// [`ChannelManager`].
200         ///
201         /// # Panics
202         ///
203         /// This function panics if the background thread has panicked such as while persisting or
204         /// handling events.
205         ///
206         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
207         pub fn join(mut self) -> Result<(), std::io::Error> {
208                 assert!(self.thread_handle.is_some());
209                 self.join_thread()
210         }
211
212         /// Stop `BackgroundProcessor`'s thread, returning any error that occurred while persisting
213         /// [`ChannelManager`].
214         ///
215         /// # Panics
216         ///
217         /// This function panics if the background thread has panicked such as while persisting or
218         /// handling events.
219         ///
220         /// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
221         pub fn stop(mut self) -> Result<(), std::io::Error> {
222                 assert!(self.thread_handle.is_some());
223                 self.stop_and_join_thread()
224         }
225
226         fn stop_and_join_thread(&mut self) -> Result<(), std::io::Error> {
227                 self.stop_thread.store(true, Ordering::Release);
228                 self.join_thread()
229         }
230
231         fn join_thread(&mut self) -> Result<(), std::io::Error> {
232                 match self.thread_handle.take() {
233                         Some(handle) => handle.join().unwrap(),
234                         None => Ok(()),
235                 }
236         }
237 }
238
239 impl Drop for BackgroundProcessor {
240         fn drop(&mut self) {
241                 self.stop_and_join_thread().unwrap();
242         }
243 }
244
245 #[cfg(test)]
246 mod tests {
247         use bitcoin::blockdata::block::BlockHeader;
248         use bitcoin::blockdata::constants::genesis_block;
249         use bitcoin::blockdata::transaction::{Transaction, TxOut};
250         use bitcoin::network::constants::Network;
251         use lightning::chain::{BestBlock, Confirm, chainmonitor};
252         use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
253         use lightning::chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager};
254         use lightning::chain::transaction::OutPoint;
255         use lightning::get_event_msg;
256         use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, ChainParameters, ChannelManager, SimpleArcChannelManager};
257         use lightning::ln::features::InitFeatures;
258         use lightning::ln::msgs::{ChannelMessageHandler, Init};
259         use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor, IgnoringMessageHandler};
260         use lightning::util::config::UserConfig;
261         use lightning::util::events::{Event, MessageSendEventsProvider, MessageSendEvent};
262         use lightning::util::ser::Writeable;
263         use lightning::util::test_utils;
264         use lightning_persister::FilesystemPersister;
265         use std::fs;
266         use std::path::PathBuf;
267         use std::sync::{Arc, Mutex};
268         use std::time::Duration;
269         use super::{BackgroundProcessor, FRESHNESS_TIMER};
270
271         const EVENT_DEADLINE: u64 = 5 * FRESHNESS_TIMER;
272
273         #[derive(Clone, Eq, Hash, PartialEq)]
274         struct TestDescriptor{}
275         impl SocketDescriptor for TestDescriptor {
276                 fn send_data(&mut self, _data: &[u8], _resume_read: bool) -> usize {
277                         0
278                 }
279
280                 fn disconnect_socket(&mut self) {}
281         }
282
283         type ChainMonitor = chainmonitor::ChainMonitor<InMemorySigner, Arc<test_utils::TestChainSource>, Arc<test_utils::TestBroadcaster>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>, Arc<FilesystemPersister>>;
284
285         struct Node {
286                 node: Arc<SimpleArcChannelManager<ChainMonitor, test_utils::TestBroadcaster, test_utils::TestFeeEstimator, test_utils::TestLogger>>,
287                 peer_manager: Arc<PeerManager<TestDescriptor, Arc<test_utils::TestChannelMessageHandler>, Arc<test_utils::TestRoutingMessageHandler>, Arc<test_utils::TestLogger>, IgnoringMessageHandler>>,
288                 chain_monitor: Arc<ChainMonitor>,
289                 persister: Arc<FilesystemPersister>,
290                 tx_broadcaster: Arc<test_utils::TestBroadcaster>,
291                 logger: Arc<test_utils::TestLogger>,
292                 best_block: BestBlock,
293         }
294
295         impl Drop for Node {
296                 fn drop(&mut self) {
297                         let data_dir = self.persister.get_data_dir();
298                         match fs::remove_dir_all(data_dir.clone()) {
299                                 Err(e) => println!("Failed to remove test persister directory {}: {}", data_dir, e),
300                                 _ => {}
301                         }
302                 }
303         }
304
305         fn get_full_filepath(filepath: String, filename: String) -> String {
306                 let mut path = PathBuf::from(filepath);
307                 path.push(filename);
308                 path.to_str().unwrap().to_string()
309         }
310
311         fn create_nodes(num_nodes: usize, persist_dir: String) -> Vec<Node> {
312                 let mut nodes = Vec::new();
313                 for i in 0..num_nodes {
314                         let tx_broadcaster = Arc::new(test_utils::TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new()), blocks: Arc::new(Mutex::new(Vec::new()))});
315                         let fee_estimator = Arc::new(test_utils::TestFeeEstimator { sat_per_kw: Mutex::new(253) });
316                         let chain_source = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
317                         let logger = Arc::new(test_utils::TestLogger::with_id(format!("node {}", i)));
318                         let persister = Arc::new(FilesystemPersister::new(format!("{}_persister_{}", persist_dir, i)));
319                         let seed = [i as u8; 32];
320                         let network = Network::Testnet;
321                         let now = Duration::from_secs(genesis_block(network).header.time as u64);
322                         let keys_manager = Arc::new(KeysManager::new(&seed, now.as_secs(), now.subsec_nanos()));
323                         let chain_monitor = Arc::new(chainmonitor::ChainMonitor::new(Some(chain_source.clone()), tx_broadcaster.clone(), logger.clone(), fee_estimator.clone(), persister.clone()));
324                         let best_block = BestBlock::from_genesis(network);
325                         let params = ChainParameters { network, best_block };
326                         let manager = Arc::new(ChannelManager::new(fee_estimator.clone(), chain_monitor.clone(), tx_broadcaster.clone(), logger.clone(), keys_manager.clone(), UserConfig::default(), params));
327                         let msg_handler = MessageHandler { chan_handler: Arc::new(test_utils::TestChannelMessageHandler::new()), route_handler: Arc::new(test_utils::TestRoutingMessageHandler::new() )};
328                         let peer_manager = Arc::new(PeerManager::new(msg_handler, keys_manager.get_node_secret(), &seed, logger.clone(), IgnoringMessageHandler{}));
329                         let node = Node { node: manager, peer_manager, chain_monitor, persister, tx_broadcaster, logger, best_block };
330                         nodes.push(node);
331                 }
332
333                 for i in 0..num_nodes {
334                         for j in (i+1)..num_nodes {
335                                 nodes[i].node.peer_connected(&nodes[j].node.get_our_node_id(), &Init { features: InitFeatures::known() });
336                                 nodes[j].node.peer_connected(&nodes[i].node.get_our_node_id(), &Init { features: InitFeatures::known() });
337                         }
338                 }
339
340                 nodes
341         }
342
343         macro_rules! open_channel {
344                 ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
345                         begin_open_channel!($node_a, $node_b, $channel_value);
346                         let events = $node_a.node.get_and_clear_pending_events();
347                         assert_eq!(events.len(), 1);
348                         let (temporary_channel_id, tx) = handle_funding_generation_ready!(events[0], $channel_value);
349                         end_open_channel!($node_a, $node_b, temporary_channel_id, tx);
350                         tx
351                 }}
352         }
353
354         macro_rules! begin_open_channel {
355                 ($node_a: expr, $node_b: expr, $channel_value: expr) => {{
356                         $node_a.node.create_channel($node_b.node.get_our_node_id(), $channel_value, 100, 42, None).unwrap();
357                         $node_b.node.handle_open_channel(&$node_a.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_a, MessageSendEvent::SendOpenChannel, $node_b.node.get_our_node_id()));
358                         $node_a.node.handle_accept_channel(&$node_b.node.get_our_node_id(), InitFeatures::known(), &get_event_msg!($node_b, MessageSendEvent::SendAcceptChannel, $node_a.node.get_our_node_id()));
359                 }}
360         }
361
362         macro_rules! handle_funding_generation_ready {
363                 ($event: expr, $channel_value: expr) => {{
364                         match $event {
365                                 Event::FundingGenerationReady { ref temporary_channel_id, ref channel_value_satoshis, ref output_script, user_channel_id } => {
366                                         assert_eq!(*channel_value_satoshis, $channel_value);
367                                         assert_eq!(user_channel_id, 42);
368
369                                         let tx = Transaction { version: 1 as i32, lock_time: 0, input: Vec::new(), output: vec![TxOut {
370                                                 value: *channel_value_satoshis, script_pubkey: output_script.clone(),
371                                         }]};
372                                         (*temporary_channel_id, tx)
373                                 },
374                                 _ => panic!("Unexpected event"),
375                         }
376                 }}
377         }
378
379         macro_rules! end_open_channel {
380                 ($node_a: expr, $node_b: expr, $temporary_channel_id: expr, $tx: expr) => {{
381                         $node_a.node.funding_transaction_generated(&$temporary_channel_id, $tx.clone()).unwrap();
382                         $node_b.node.handle_funding_created(&$node_a.node.get_our_node_id(), &get_event_msg!($node_a, MessageSendEvent::SendFundingCreated, $node_b.node.get_our_node_id()));
383                         $node_a.node.handle_funding_signed(&$node_b.node.get_our_node_id(), &get_event_msg!($node_b, MessageSendEvent::SendFundingSigned, $node_a.node.get_our_node_id()));
384                 }}
385         }
386
387         fn confirm_transaction_depth(node: &mut Node, tx: &Transaction, depth: u32) {
388                 for i in 1..=depth {
389                         let prev_blockhash = node.best_block.block_hash();
390                         let height = node.best_block.height() + 1;
391                         let header = BlockHeader { version: 0x20000000, prev_blockhash, merkle_root: Default::default(), time: height, bits: 42, nonce: 42 };
392                         let txdata = vec![(0, tx)];
393                         node.best_block = BestBlock::new(header.block_hash(), height);
394                         match i {
395                                 1 => {
396                                         node.node.transactions_confirmed(&header, &txdata, height);
397                                         node.chain_monitor.transactions_confirmed(&header, &txdata, height);
398                                 },
399                                 x if x == depth => {
400                                         node.node.best_block_updated(&header, height);
401                                         node.chain_monitor.best_block_updated(&header, height);
402                                 },
403                                 _ => {},
404                         }
405                 }
406         }
407         fn confirm_transaction(node: &mut Node, tx: &Transaction) {
408                 confirm_transaction_depth(node, tx, ANTI_REORG_DELAY);
409         }
410
411         #[test]
412         fn test_background_processor() {
413                 // Test that when a new channel is created, the ChannelManager needs to be re-persisted with
414                 // updates. Also test that when new updates are available, the manager signals that it needs
415                 // re-persistence and is successfully re-persisted.
416                 let nodes = create_nodes(2, "test_background_processor".to_string());
417
418                 // Go through the channel creation process so that each node has something to persist. Since
419                 // open_channel consumes events, it must complete before starting BackgroundProcessor to
420                 // avoid a race with processing events.
421                 let tx = open_channel!(nodes[0], nodes[1], 100000);
422
423                 // Initiate the background processors to watch each node.
424                 let data_dir = nodes[0].persister.get_data_dir();
425                 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);
426                 let event_handler = |_| {};
427                 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());
428
429                 macro_rules! check_persisted_data {
430                         ($node: expr, $filepath: expr, $expected_bytes: expr) => {
431                                 match $node.write(&mut $expected_bytes) {
432                                         Ok(()) => {
433                                                 loop {
434                                                         match std::fs::read($filepath) {
435                                                                 Ok(bytes) => {
436                                                                         if bytes == $expected_bytes {
437                                                                                 break
438                                                                         } else {
439                                                                                 continue
440                                                                         }
441                                                                 },
442                                                                 Err(_) => continue
443                                                         }
444                                                 }
445                                         },
446                                         Err(e) => panic!("Unexpected error: {}", e)
447                                 }
448                         }
449                 }
450
451                 // Check that the initial channel manager data is persisted as expected.
452                 let filepath = get_full_filepath("test_background_processor_persister_0".to_string(), "manager".to_string());
453                 let mut expected_bytes = Vec::new();
454                 check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
455                 loop {
456                         if !nodes[0].node.get_persistence_condvar_value() { break }
457                 }
458
459                 // Force-close the channel.
460                 nodes[0].node.force_close_channel(&OutPoint { txid: tx.txid(), index: 0 }.to_channel_id()).unwrap();
461
462                 // Check that the force-close updates are persisted.
463                 let mut expected_bytes = Vec::new();
464                 check_persisted_data!(nodes[0].node, filepath.clone(), expected_bytes);
465                 loop {
466                         if !nodes[0].node.get_persistence_condvar_value() { break }
467                 }
468
469                 assert!(bg_processor.stop().is_ok());
470         }
471
472         #[test]
473         fn test_timer_tick_called() {
474                 // Test that ChannelManager's and PeerManager's `timer_tick_occurred` is called every
475                 // `FRESHNESS_TIMER`.
476                 let nodes = create_nodes(1, "test_timer_tick_called".to_string());
477                 let data_dir = nodes[0].persister.get_data_dir();
478                 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);
479                 let event_handler = |_| {};
480                 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());
481                 loop {
482                         let log_entries = nodes[0].logger.lines.lock().unwrap();
483                         let desired_log = "Calling ChannelManager's timer_tick_occurred".to_string();
484                         let second_desired_log = "Calling PeerManager's timer_tick_occurred".to_string();
485                         if log_entries.get(&("lightning_background_processor".to_string(), desired_log)).is_some() &&
486                                         log_entries.get(&("lightning_background_processor".to_string(), second_desired_log)).is_some() {
487                                 break
488                         }
489                 }
490
491                 assert!(bg_processor.stop().is_ok());
492         }
493
494         #[test]
495         fn test_persist_error() {
496                 // Test that if we encounter an error during manager persistence, the thread panics.
497                 let nodes = create_nodes(2, "test_persist_error".to_string());
498                 open_channel!(nodes[0], nodes[1], 100000);
499
500                 let persister = |_: &_| Err(std::io::Error::new(std::io::ErrorKind::Other, "test"));
501                 let event_handler = |_| {};
502                 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());
503                 match bg_processor.join() {
504                         Ok(_) => panic!("Expected error persisting manager"),
505                         Err(e) => {
506                                 assert_eq!(e.kind(), std::io::ErrorKind::Other);
507                                 assert_eq!(e.get_ref().unwrap().to_string(), "test");
508                         },
509                 }
510         }
511
512         #[test]
513         fn test_background_event_handling() {
514                 let mut nodes = create_nodes(2, "test_background_event_handling".to_string());
515                 let channel_value = 100000;
516                 let data_dir = nodes[0].persister.get_data_dir();
517                 let persister = move |node: &_| FilesystemPersister::persist_manager(data_dir.clone(), node);
518
519                 // Set up a background event handler for FundingGenerationReady events.
520                 let (sender, receiver) = std::sync::mpsc::sync_channel(1);
521                 let event_handler = move |event| {
522                         sender.send(handle_funding_generation_ready!(event, channel_value)).unwrap();
523                 };
524                 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());
525
526                 // Open a channel and check that the FundingGenerationReady event was handled.
527                 begin_open_channel!(nodes[0], nodes[1], channel_value);
528                 let (temporary_channel_id, funding_tx) = receiver
529                         .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
530                         .expect("FundingGenerationReady not handled within deadline");
531                 end_open_channel!(nodes[0], nodes[1], temporary_channel_id, funding_tx);
532
533                 // Confirm the funding transaction.
534                 confirm_transaction(&mut nodes[0], &funding_tx);
535                 let as_funding = get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id());
536                 confirm_transaction(&mut nodes[1], &funding_tx);
537                 let bs_funding = get_event_msg!(nodes[1], MessageSendEvent::SendFundingLocked, nodes[0].node.get_our_node_id());
538                 nodes[0].node.handle_funding_locked(&nodes[1].node.get_our_node_id(), &bs_funding);
539                 let _as_channel_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
540                 nodes[1].node.handle_funding_locked(&nodes[0].node.get_our_node_id(), &as_funding);
541                 let _bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
542
543                 assert!(bg_processor.stop().is_ok());
544
545                 // Set up a background event handler for SpendableOutputs events.
546                 let (sender, receiver) = std::sync::mpsc::sync_channel(1);
547                 let event_handler = move |event| sender.send(event).unwrap();
548                 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());
549
550                 // Force close the channel and check that the SpendableOutputs event was handled.
551                 nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id).unwrap();
552                 let commitment_tx = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().pop().unwrap();
553                 confirm_transaction_depth(&mut nodes[0], &commitment_tx, BREAKDOWN_TIMEOUT as u32);
554                 let event = receiver
555                         .recv_timeout(Duration::from_secs(EVENT_DEADLINE))
556                         .expect("SpendableOutputs not handled within deadline");
557                 match event {
558                         Event::SpendableOutputs { .. } => {},
559                         _ => panic!("Unexpected event: {:?}", event),
560                 }
561
562                 assert!(bg_processor.stop().is_ok());
563         }
564 }