f - wait two timer ticks instead of one

Author: jkczyz

lightning/src/onion_message/messenger.rs

@@ -164,22 +164,27 @@ enum OnionMessageBuffer {
 	/// Messages for a node connected as a peer.
 	ConnectedPeer(VecDeque<OnionMessage>),
 
-	/// Messages for a node that is not yet connected.
-	PendingConnection(VecDeque<OnionMessage>, Option<Vec<SocketAddress>>),
+	/// Messages for a node that is not yet connected, which are dropped after a certain number of
+	/// timer ticks defined in OnionMessenger::release_pending_connections and tracked here.
+	PendingConnection(VecDeque<OnionMessage>, Option<Vec<SocketAddress>>, usize),
 }
 
 impl OnionMessageBuffer {
+	fn pending_connection(addresses: Vec<SocketAddress>) -> Self {
+		Self::PendingConnection(VecDeque::new(), Some(addresses), 0)
+	}
+
 	fn pending_messages(&self) -> &VecDeque<OnionMessage> {
 		match self {
 			OnionMessageBuffer::ConnectedPeer(pending_messages) => pending_messages,
-			OnionMessageBuffer::PendingConnection(pending_messages, _) => pending_messages,
+			OnionMessageBuffer::PendingConnection(pending_messages, _, _) => pending_messages,
 		}
 	}
 
 	fn enqueue_message(&mut self, message: OnionMessage) {
 		let pending_messages = match self {
 			OnionMessageBuffer::ConnectedPeer(pending_messages) => pending_messages,
-			OnionMessageBuffer::PendingConnection(pending_messages, _) => pending_messages,
+			OnionMessageBuffer::PendingConnection(pending_messages, _, _) => pending_messages,
 		};
 
 		pending_messages.push_back(message);
@@ -188,7 +193,7 @@ impl OnionMessageBuffer {
 	fn dequeue_message(&mut self) -> Option<OnionMessage> {
 		let pending_messages = match self {
 			OnionMessageBuffer::ConnectedPeer(pending_messages) => pending_messages,
-			OnionMessageBuffer::PendingConnection(pending_messages, _) => {
+			OnionMessageBuffer::PendingConnection(pending_messages, _, _) => {
 				debug_assert!(false);
 				pending_messages
 			},
@@ -201,14 +206,14 @@ impl OnionMessageBuffer {
 	fn release_pending_messages(&mut self) -> VecDeque<OnionMessage> {
 		let pending_messages = match self {
 			OnionMessageBuffer::ConnectedPeer(pending_messages) => pending_messages,
-			OnionMessageBuffer::PendingConnection(pending_messages, _) => pending_messages,
+			OnionMessageBuffer::PendingConnection(pending_messages, _, _) => pending_messages,
 		};
 
 		core::mem::take(pending_messages)
 	}
 
 	fn mark_connected(&mut self) {
-		if let OnionMessageBuffer::PendingConnection(pending_messages, _) = self {
+		if let OnionMessageBuffer::PendingConnection(pending_messages, _, _) = self {
 			let mut new_pending_messages = VecDeque::new();
 			core::mem::swap(pending_messages, &mut new_pending_messages);
 			*self = OnionMessageBuffer::ConnectedPeer(new_pending_messages);
@@ -670,9 +675,8 @@ where
 			hash_map::Entry::Vacant(e) => match addresses {
 				None => Err(SendError::InvalidFirstHop(first_node_id)),
 				Some(addresses) => {
-					e.insert(
-						OnionMessageBuffer::PendingConnection(VecDeque::new(), Some(addresses))
-					).enqueue_message(onion_message);
+					e.insert(OnionMessageBuffer::pending_connection(addresses))
+						.enqueue_message(onion_message);
 					Ok(SendSuccess::BufferedAwaitingConnection(first_node_id))
 				},
 			},
@@ -774,7 +778,7 @@ where
 {
 	fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler {
 		for (node_id, recipient) in self.message_buffers.lock().unwrap().iter_mut() {
-			if let OnionMessageBuffer::PendingConnection(_, addresses) = recipient {
+			if let OnionMessageBuffer::PendingConnection(_, addresses, _) = recipient {
 				if let Some(addresses) = addresses.take() {
 					handler.handle_event(Event::ConnectionNeeded { node_id: *node_id, addresses });
 				}
@@ -872,13 +876,24 @@ where
 	}
 
 	fn timer_tick_occurred(&self) {
+		const MAX_TIMER_TICKS: usize = 2;
+		let mut message_buffers = self.message_buffers.lock().unwrap();
+
 		// Drop any pending recipients since the last call to avoid retaining buffered messages for
 		// too long.
-		self.message_buffers.lock().unwrap().retain(|_, recipient| match recipient {
-			OnionMessageBuffer::PendingConnection(_, None) => false,
-			OnionMessageBuffer::PendingConnection(_, Some(_)) => true,
+		message_buffers.retain(|_, recipient| match recipient {
+			OnionMessageBuffer::PendingConnection(_, None, ticks) => *ticks < MAX_TIMER_TICKS,
+			OnionMessageBuffer::PendingConnection(_, Some(_), _) => true,
 			_ => true,
 		});
+
+		// Increment a timer tick for pending recipients so that their buffered messages are dropped
+		// at MAX_TIMER_TICKS.
+		for recipient in message_buffers.values_mut() {
+			if let OnionMessageBuffer::PendingConnection(_, Some(_), ticks) = recipient {
+				*ticks += 1;
+			}
+		}
 	}
 
 	fn provided_node_features(&self) -> NodeFeatures {