Test utils: allow queueing >2 persistence update results

lightning/src/ln/chanmon_update_fail_tests.rs

@@ -1959,7 +1959,7 @@ fn test_path_paused_mpp() {
 	// Set it so that the first monitor update (for the path 0 -> 1 -> 3) succeeds, but the second
 	// (for the path 0 -> 2 -> 3) fails.
 	chanmon_cfgs[0].persister.set_update_ret(ChannelMonitorUpdateStatus::Completed);
-	chanmon_cfgs[0].persister.set_next_update_ret(Some(ChannelMonitorUpdateStatus::InProgress));
+	chanmon_cfgs[0].persister.set_next_update_ret(ChannelMonitorUpdateStatus::InProgress);
 
 	// Now check that we get the right return value, indicating that the first path succeeded but
 	// the second got a MonitorUpdateInProgress err. This implies

lightning/src/util/test_utils.rs

@@ -224,10 +224,9 @@ impl<'a> chain::Watch<EnforcingSigner> for TestChainMonitor<'a> {
 }
 
 pub struct TestPersister {
-	pub update_ret: Mutex<chain::ChannelMonitorUpdateStatus>,
-	/// If this is set to Some(), after the next return, we'll always return this until update_ret
-	/// is changed:
-	pub next_update_ret: Mutex<Option<chain::ChannelMonitorUpdateStatus>>,
+	/// The queue of update statuses we'll return. If only one is queued, we'll always return it. If
+	/// none are queued, ::Completed will always be returned.
+	pub update_rets: Mutex<VecDeque<chain::ChannelMonitorUpdateStatus>>,
 	/// When we get an update_persisted_channel call with no ChannelMonitorUpdate, we insert the
 	/// MonitorUpdateId here.
 	pub chain_sync_monitor_persistences: Mutex<HashMap<OutPoint, HashSet<MonitorUpdateId>>>,
@@ -238,35 +237,39 @@ pub struct TestPersister {
 impl TestPersister {
 	pub fn new() -> Self {
 		Self {
-			update_ret: Mutex::new(chain::ChannelMonitorUpdateStatus::Completed),
-			next_update_ret: Mutex::new(None),
+			update_rets: Mutex::new(VecDeque::new()),
 			chain_sync_monitor_persistences: Mutex::new(HashMap::new()),
 			offchain_monitor_updates: Mutex::new(HashMap::new()),
 		}
 	}
 
+	/// Clear the queue of update statuses and set the one we'll always return.
 	pub fn set_update_ret(&self, ret: chain::ChannelMonitorUpdateStatus) {
-		*self.update_ret.lock().unwrap() = ret;
+		let mut update_rets = self.update_rets.lock().unwrap();
+		update_rets.clear();
+		update_rets.push_front(ret);
 	}
 
-	pub fn set_next_update_ret(&self, next_ret: Option<chain::ChannelMonitorUpdateStatus>) {
-		*self.next_update_ret.lock().unwrap() = next_ret;
+	/// Queue an update status to return.
+	pub fn set_next_update_ret(&self, next_ret: chain::ChannelMonitorUpdateStatus) {
+		self.update_rets.lock().unwrap().push_back(next_ret);
 	}
 }
 impl<Signer: keysinterface::Sign> chainmonitor::Persist<Signer> for TestPersister {
 	fn persist_new_channel(&self, _funding_txo: OutPoint, _data: &channelmonitor::ChannelMonitor<Signer>, _id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
-		let ret = self.update_ret.lock().unwrap().clone();
-		if let Some(next_ret) = self.next_update_ret.lock().unwrap().take() {
-			*self.update_ret.lock().unwrap() = next_ret;
-		}
-		ret
+		let mut update_rets = self.update_rets.lock().unwrap();
+		if update_rets.len() > 1 { return update_rets.pop_front().unwrap() }
+		else if update_rets.len() == 1 { return *update_rets.front().clone().unwrap() }
+		chain::ChannelMonitorUpdateStatus::Completed
 	}
 
 	fn update_persisted_channel(&self, funding_txo: OutPoint, update: &Option<channelmonitor::ChannelMonitorUpdate>, _data: &channelmonitor::ChannelMonitor<Signer>, update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
-		let ret = self.update_ret.lock().unwrap().clone();
-		if let Some(next_ret) = self.next_update_ret.lock().unwrap().take() {
-			*self.update_ret.lock().unwrap() = next_ret;
-		}
+		let ret = {
+			let mut update_rets = self.update_rets.lock().unwrap();
+			if update_rets.len() > 1 { update_rets.pop_front().unwrap() }
+			else if update_rets.len() == 1 { *update_rets.front().clone().unwrap() }
+			else { chain::ChannelMonitorUpdateStatus::Completed }
+		};
 		if update.is_none() {
 			self.chain_sync_monitor_persistences.lock().unwrap().entry(funding_txo).or_insert(HashSet::new()).insert(update_id);
 		} else {