Drop PeerHolder as it now only has one field

Author: TheBlueMatt

lightning/src/ln/peer_handler.rs

@@ -376,14 +376,6 @@ impl Peer {
 	}
 }
 
-struct PeerHolder<Descriptor: SocketDescriptor> {
-	/// Peer is under its own mutex for sending and receiving bytes, but note that we do *not* hold
-	/// this mutex while we're processing a message. This is fine as [`PeerManager::read_event`]
-	/// requires that there be no parallel calls for a given peer, so mutual exclusion of messages
-	/// handed to the `MessageHandler`s for a given peer is already guaranteed.
-	peers: HashMap<Descriptor, Mutex<Peer>>,
-}
-
 /// SimpleArcPeerManager is useful when you need a PeerManager with a static lifetime, e.g.
 /// when you're using lightning-net-tokio (since tokio::spawn requires parameters with static
 /// lifetimes). Other times you can afford a reference, which is more efficient, in which case
@@ -428,7 +420,15 @@ pub struct PeerManager<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: De
 		L::Target: Logger,
 		CMH::Target: CustomMessageHandler {
 	message_handler: MessageHandler<CM, RM>,
-	peers: FairRwLock<PeerHolder<Descriptor>>,
+	/// Connection state for each connected peer - we have an outer read-write lock which is taken
+	/// as read while we're doing processing for a peer and taken write when a peer is being added
+	/// or removed.
+	///
+	/// The inner Peer lock is held for sending and receiving bytes, but note that we do *not* hold
+	/// it while we're processing a message. This is fine as [`PeerManager::read_event`] requires
+	/// that there be no parallel calls for a given peer, so mutual exclusion of messages handed to
+	/// the `MessageHandler`s for a given peer is already guaranteed.
+	peers: FairRwLock<HashMap<Descriptor, Mutex<Peer>>>,
 	/// Only add to this set when noise completes.
 	/// Locked *after* peers. When an item is removed, it must be removed with the `peers` write
 	/// lock held. Entries may be added with only the `peers` read lock held (though the
@@ -570,9 +570,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 
 		PeerManager {
 			message_handler,
-			peers: FairRwLock::new(PeerHolder {
-				peers: HashMap::new(),
-			}),
+			peers: FairRwLock::new(HashMap::new()),
 			node_id_to_descriptor: Mutex::new(HashMap::new()),
 			event_processing_lock: Mutex::new(()),
 			blocked_event_processors: AtomicBool::new(false),
@@ -591,7 +589,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 	/// completed and we are sure the remote peer has the private key for the given node_id.
 	pub fn get_peer_node_ids(&self) -> Vec<PublicKey> {
 		let peers = self.peers.read().unwrap();
-		peers.peers.values().filter_map(|peer_mutex| {
+		peers.values().filter_map(|peer_mutex| {
 			let p = peer_mutex.lock().unwrap();
 			if !p.channel_encryptor.is_ready_for_encryption() || p.their_features.is_none() {
 				return None;
@@ -629,7 +627,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 		let pending_read_buffer = [0; 50].to_vec(); // Noise act two is 50 bytes
 
 		let mut peers = self.peers.write().unwrap();
-		if peers.peers.insert(descriptor, Mutex::new(Peer {
+		if peers.insert(descriptor, Mutex::new(Peer {
 			channel_encryptor: peer_encryptor,
 			their_node_id: None,
 			their_features: None,
@@ -676,7 +674,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 		let pending_read_buffer = [0; 50].to_vec(); // Noise act one is 50 bytes
 
 		let mut peers = self.peers.write().unwrap();
-		if peers.peers.insert(descriptor, Mutex::new(Peer {
+		if peers.insert(descriptor, Mutex::new(Peer {
 			channel_encryptor: peer_encryptor,
 			their_node_id: None,
 			their_features: None,
@@ -787,7 +785,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 	/// [`write_buffer_space_avail`]: PeerManager::write_buffer_space_avail
 	pub fn write_buffer_space_avail(&self, descriptor: &mut Descriptor) -> Result<(), PeerHandleError> {
 		let peers = self.peers.read().unwrap();
-		match peers.peers.get(descriptor) {
+		match peers.get(descriptor) {
 			None => {
 				// This is most likely a simple race condition where the user found that the socket
 				// was writeable, then we told the user to `disconnect_socket()`, then they called
@@ -852,7 +850,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 		let peers = self.peers.read().unwrap();
 		let mut msgs_to_forward = Vec::new();
 		let mut peer_node_id = None;
-		match peers.peers.get(peer_descriptor) {
+		match peers.get(peer_descriptor) {
 			None => {
 				// This is most likely a simple race condition where the user read some bytes
 				// from the socket, then we told the user to `disconnect_socket()`, then they
@@ -1288,13 +1286,13 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 		Ok(should_forward)
 	}
 
-	fn forward_broadcast_msg(&self, peers: &PeerHolder<Descriptor>, msg: &wire::Message<<<CMH as core::ops::Deref>::Target as wire::CustomMessageReader>::CustomMessage>, except_node: Option<&PublicKey>) {
+	fn forward_broadcast_msg(&self, peers: &HashMap<Descriptor, Mutex<Peer>>, msg: &wire::Message<<<CMH as core::ops::Deref>::Target as wire::CustomMessageReader>::CustomMessage>, except_node: Option<&PublicKey>) {
 		match msg {
 			wire::Message::ChannelAnnouncement(ref msg) => {
 				log_gossip!(self.logger, "Sending message to all peers except {:?} or the announced channel's counterparties: {:?}", except_node, msg);
 				let encoded_msg = encode_msg!(msg);
 
-				for (_, peer_mutex) in peers.peers.iter() {
+				for (_, peer_mutex) in peers.iter() {
 					let mut peer = peer_mutex.lock().unwrap();
 					if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
 							!peer.should_forward_channel_announcement(msg.contents.short_channel_id) {
@@ -1320,7 +1318,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 				log_gossip!(self.logger, "Sending message to all peers except {:?} or the announced node: {:?}", except_node, msg);
 				let encoded_msg = encode_msg!(msg);
 
-				for (_, peer_mutex) in peers.peers.iter() {
+				for (_, peer_mutex) in peers.iter() {
 					let mut peer = peer_mutex.lock().unwrap();
 					if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
 							!peer.should_forward_node_announcement(msg.contents.node_id) {
@@ -1345,7 +1343,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 				log_gossip!(self.logger, "Sending message to all peers except {:?}: {:?}", except_node, msg);
 				let encoded_msg = encode_msg!(msg);
 
-				for (_, peer_mutex) in peers.peers.iter() {
+				for (_, peer_mutex) in peers.iter() {
 					let mut peer = peer_mutex.lock().unwrap();
 					if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
 							!peer.should_forward_channel_announcement(msg.contents.short_channel_id)  {
@@ -1426,7 +1424,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 						}
 						let descriptor_opt = self.node_id_to_descriptor.lock().unwrap().get($node_id).cloned();
 						match descriptor_opt {
-							Some(descriptor) => match peers.peers.get(&descriptor) {
+							Some(descriptor) => match peers.get(&descriptor) {
 								Some(peer_mutex) => {
 									let peer_lock = peer_mutex.lock().unwrap();
 									if peer_lock.their_features.is_none() {
@@ -1625,7 +1623,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 				self.enqueue_message(&mut *get_peer_for_forwarding!(&node_id), &msg);
 			}
 
-			for (descriptor, peer_mutex) in peers.peers.iter() {
+			for (descriptor, peer_mutex) in peers.iter() {
 				self.do_attempt_write_data(&mut (*descriptor).clone(), &mut *peer_mutex.lock().unwrap());
 			}
 		}
@@ -1639,7 +1637,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 				// lock).
 
 				if let Some(mut descriptor) = self.node_id_to_descriptor.lock().unwrap().remove(&node_id) {
-					if let Some(peer_mutex) = peers.peers.remove(&descriptor) {
+					if let Some(peer_mutex) = peers.remove(&descriptor) {
 						if let Some(msg) = msg {
 							log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {} with message {}",
 									log_pubkey!(node_id),
@@ -1667,7 +1665,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 
 	fn disconnect_event_internal(&self, descriptor: &Descriptor, no_connection_possible: bool) {
 		let mut peers = self.peers.write().unwrap();
-		let peer_option = peers.peers.remove(descriptor);
+		let peer_option = peers.remove(descriptor);
 		match peer_option {
 			None => {
 				// This is most likely a simple race condition where the user found that the socket
@@ -1703,7 +1701,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 		let mut peers_lock = self.peers.write().unwrap();
 		if let Some(mut descriptor) = self.node_id_to_descriptor.lock().unwrap().remove(&node_id) {
 			log_trace!(self.logger, "Disconnecting peer with id {} due to client request", node_id);
-			peers_lock.peers.remove(&descriptor);
+			peers_lock.remove(&descriptor);
 			self.message_handler.chan_handler.peer_disconnected(&node_id, no_connection_possible);
 			descriptor.disconnect_socket();
 		}
@@ -1716,7 +1714,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 		let mut peers_lock = self.peers.write().unwrap();
 		self.node_id_to_descriptor.lock().unwrap().clear();
 		let peers = &mut *peers_lock;
-		for (mut descriptor, peer) in peers.peers.drain() {
+		for (mut descriptor, peer) in peers.drain() {
 			if let Some(node_id) = peer.lock().unwrap().their_node_id {
 				log_trace!(self.logger, "Disconnecting peer with id {} due to client request to disconnect all peers", node_id);
 				self.message_handler.chan_handler.peer_disconnected(&node_id, false);
@@ -1755,7 +1753,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 		{
 			let peers_lock = self.peers.read().unwrap();
 
-			for (descriptor, peer_mutex) in peers_lock.peers.iter() {
+			for (descriptor, peer_mutex) in peers_lock.iter() {
 				let mut peer = peer_mutex.lock().unwrap();
 				if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_node_id.is_none() {
 					// The peer needs to complete its handshake before we can exchange messages. We
@@ -1779,7 +1777,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 
 				if (peer.awaiting_pong_timer_tick_intervals > 0 && !peer.received_message_since_timer_tick)
 					|| peer.awaiting_pong_timer_tick_intervals as u64 >
-						MAX_BUFFER_DRAIN_TICK_INTERVALS_PER_PEER as u64 * peers_lock.peers.len() as u64
+						MAX_BUFFER_DRAIN_TICK_INTERVALS_PER_PEER as u64 * peers_lock.len() as u64
 				{
 					descriptors_needing_disconnect.push(descriptor.clone());
 					continue;
@@ -1805,7 +1803,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 			{
 				let mut peers_lock = self.peers.write().unwrap();
 				for descriptor in descriptors_needing_disconnect.iter() {
-					if let Some(peer) = peers_lock.peers.remove(&descriptor) {
+					if let Some(peer) = peers_lock.remove(descriptor) {
 						if let Some(node_id) = peer.lock().unwrap().their_node_id {
 							log_trace!(self.logger, "Disconnecting peer with id {} due to ping timeout", node_id);
 							self.node_id_to_descriptor.lock().unwrap().remove(&node_id);
@@ -1935,7 +1933,7 @@ mod tests {
 		let chan_handler = test_utils::TestChannelMessageHandler::new();
 		let mut peers = create_network(2, &cfgs);
 		establish_connection(&peers[0], &peers[1]);
-		assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
+		assert_eq!(peers[0].peers.read().unwrap().len(), 1);
 
 		let secp_ctx = Secp256k1::new();
 		let their_id = PublicKey::from_secret_key(&secp_ctx, &peers[1].our_node_secret);
@@ -1948,7 +1946,7 @@ mod tests {
 		peers[0].message_handler.chan_handler = &chan_handler;
 
 		peers[0].process_events();
-		assert_eq!(peers[0].peers.read().unwrap().peers.len(), 0);
+		assert_eq!(peers[0].peers.read().unwrap().len(), 0);
 	}
 
 	#[test]
@@ -1957,17 +1955,17 @@ mod tests {
 		let cfgs = create_peermgr_cfgs(2);
 		let peers = create_network(2, &cfgs);
 		establish_connection(&peers[0], &peers[1]);
-		assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
+		assert_eq!(peers[0].peers.read().unwrap().len(), 1);
 
 		// peers[0] awaiting_pong is set to true, but the Peer is still connected
 		peers[0].timer_tick_occurred();
 		peers[0].process_events();
-		assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
+		assert_eq!(peers[0].peers.read().unwrap().len(), 1);
 
 		// Since timer_tick_occurred() is called again when awaiting_pong is true, all Peers are disconnected
 		peers[0].timer_tick_occurred();
 		peers[0].process_events();
-		assert_eq!(peers[0].peers.read().unwrap().peers.len(), 0);
+		assert_eq!(peers[0].peers.read().unwrap().len(), 0);
 	}
 
 	#[test]
@@ -2029,9 +2027,9 @@ mod tests {
 		peers[0].new_inbound_connection(fd_a.clone(), None).unwrap();
 
 		// If we get a single timer tick before completion, that's fine
-		assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
+		assert_eq!(peers[0].peers.read().unwrap().len(), 1);
 		peers[0].timer_tick_occurred();
-		assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
+		assert_eq!(peers[0].peers.read().unwrap().len(), 1);
 
 		assert_eq!(peers[0].read_event(&mut fd_a, &initial_data).unwrap(), false);
 		peers[0].process_events();
@@ -2040,7 +2038,7 @@ mod tests {
 
 		// ...but if we get a second timer tick, we should disconnect the peer
 		peers[0].timer_tick_occurred();
-		assert_eq!(peers[0].peers.read().unwrap().peers.len(), 0);
+		assert_eq!(peers[0].peers.read().unwrap().len(), 0);
 
 		assert!(peers[0].read_event(&mut fd_a, &fd_b.outbound_data.lock().unwrap().split_off(0)).is_err());
 	}