Drop peers_needing_send tracking and try to write for each peer
authorMatt Corallo <git@bluematt.me>
Thu, 10 Jun 2021 18:46:24 +0000 (18:46 +0000)
committerMatt Corallo <git@bluematt.me>
Mon, 21 Jun 2021 19:45:17 +0000 (19:45 +0000)
We do a lot of work to track which peers have buffers which need
to be flushed, when we could instead just try to flush ever peer's
buffer.

lightning/src/ln/peer_handler.rs

index 14d2d7de622abfe2a3e5b6be77433de4fe7b0355..c5128e25b055bab5b7be4f1e6651cd5501199144 100644 (file)
@@ -287,9 +287,6 @@ impl Peer {
 
 struct PeerHolder<Descriptor: SocketDescriptor> {
        peers: HashMap<Descriptor, Peer>,
-       /// Added to by do_read_event for cases where we pushed a message onto the send buffer but
-       /// didn't call do_attempt_write_data to avoid reentrancy. Cleared in process_events()
-       peers_needing_send: HashSet<Descriptor>,
        /// Only add to this set when noise completes:
        node_id_to_descriptor: HashMap<PublicKey, Descriptor>,
 }
@@ -420,7 +417,6 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                        message_handler,
                        peers: Mutex::new(PeerHolder {
                                peers: HashMap::new(),
-                               peers_needing_send: HashSet::new(),
                                node_id_to_descriptor: HashMap::new()
                        }),
                        our_node_secret,
@@ -652,14 +648,13 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
        }
 
        /// Append a message to a peer's pending outbound/write buffer, and update the map of peers needing sends accordingly.
-       fn enqueue_message<M: Encode + Writeable>(&self, peers_needing_send: &mut HashSet<Descriptor>, peer: &mut Peer, descriptor: Descriptor, message: &M) {
+       fn enqueue_message<M: Encode + Writeable>(&self, peer: &mut Peer, message: &M) {
                let mut buffer = VecWriter(Vec::new());
                wire::write(message, &mut buffer).unwrap(); // crash if the write failed
                let encoded_message = buffer.0;
 
                log_trace!(self.logger, "Enqueueing message of type {} to {}", message.type_id(), log_pubkey!(peer.their_node_id.unwrap()));
                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_message[..]));
-               peers_needing_send.insert(descriptor);
        }
 
        fn do_read_event(&self, peer_descriptor: &mut Descriptor, data: &[u8]) -> Result<bool, PeerHandleError> {
@@ -703,7 +698,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                                                                },
                                                                                                msgs::ErrorAction::SendErrorMessage { msg } => {
                                                                                                        log_trace!(self.logger, "Got Err handling message, sending Error message because {}", e.err);
-                                                                                                       self.enqueue_message(&mut peers.peers_needing_send, peer, peer_descriptor.clone(), &msg);
+                                                                                                       self.enqueue_message(peer, &msg);
                                                                                                        continue;
                                                                                                },
                                                                                        }
@@ -745,7 +740,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                                        insert_node_id!();
                                                                        let features = InitFeatures::known();
                                                                        let resp = msgs::Init { features };
-                                                                       self.enqueue_message(&mut peers.peers_needing_send, peer, peer_descriptor.clone(), &resp);
+                                                                       self.enqueue_message(peer, &resp);
                                                                },
                                                                NextNoiseStep::ActThree => {
                                                                        let their_node_id = try_potential_handleerror!(peer.channel_encryptor.process_act_three(&peer.pending_read_buffer[..]));
@@ -755,7 +750,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                                        insert_node_id!();
                                                                        let features = InitFeatures::known();
                                                                        let resp = msgs::Init { features };
-                                                                       self.enqueue_message(&mut peers.peers_needing_send, peer, peer_descriptor.clone(), &resp);
+                                                                       self.enqueue_message(peer, &resp);
                                                                },
                                                                NextNoiseStep::NoiseComplete => {
                                                                        if peer.pending_read_is_header {
@@ -803,7 +798,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                                                        }
                                                                                };
 
-                                                                               match self.handle_message(&mut peers.peers_needing_send, peer, peer_descriptor.clone(), message) {
+                                                                               match self.handle_message(peer, message) {
                                                                                        Err(handling_error) => match handling_error {
                                                                                                MessageHandlingError::PeerHandleError(e) => { return Err(e) },
                                                                                                MessageHandlingError::LightningError(e) => {
@@ -838,7 +833,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
 
        /// Process an incoming message and return a decision (ok, lightning error, peer handling error) regarding the next action with the peer
        /// Returns the message back if it needs to be broadcasted to all other peers.
-       fn handle_message(&self, peers_needing_send: &mut HashSet<Descriptor>, peer: &mut Peer, peer_descriptor: Descriptor, message: wire::Message) -> Result<Option<wire::Message>, MessageHandlingError> {
+       fn handle_message(&self, peer: &mut Peer, message: wire::Message) -> Result<Option<wire::Message>, MessageHandlingError> {
                log_trace!(self.logger, "Received message of type {} from {}", message.type_id(), log_pubkey!(peer.their_node_id.unwrap()));
 
                // Need an Init as first message
@@ -873,7 +868,6 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
 
                                if msg.features.initial_routing_sync() {
                                        peer.sync_status = InitSyncTracker::ChannelsSyncing(0);
-                                       peers_needing_send.insert(peer_descriptor.clone());
                                }
                                if !msg.features.supports_static_remote_key() {
                                        log_debug!(self.logger, "Peer {} does not support static remote key, disconnecting with no_connection_possible", log_pubkey!(peer.their_node_id.unwrap()));
@@ -908,7 +902,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                        wire::Message::Ping(msg) => {
                                if msg.ponglen < 65532 {
                                        let resp = msgs::Pong { byteslen: msg.ponglen };
-                                       self.enqueue_message(peers_needing_send, peer, peer_descriptor.clone(), &resp);
+                                       self.enqueue_message(peer, &resp);
                                }
                        },
                        wire::Message::Pong(_msg) => {
@@ -1030,7 +1024,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                        wire::Message::ChannelAnnouncement(ref msg) => {
                                let encoded_msg = encode_msg!(msg);
 
-                               for (ref descriptor, ref mut peer) in peers.peers.iter_mut() {
+                               for (_, peer) in peers.peers.iter_mut() {
                                        if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
                                                        !peer.should_forward_channel_announcement(msg.contents.short_channel_id) {
                                                continue
@@ -1046,13 +1040,12 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                continue;
                                        }
                                        peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_msg[..]));
-                                       peers.peers_needing_send.insert((*descriptor).clone());
                                }
                        },
                        wire::Message::NodeAnnouncement(ref msg) => {
                                let encoded_msg = encode_msg!(msg);
 
-                               for (ref descriptor, ref mut peer) in peers.peers.iter_mut() {
+                               for (_, peer) in peers.peers.iter_mut() {
                                        if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
                                                        !peer.should_forward_node_announcement(msg.contents.node_id) {
                                                continue
@@ -1067,13 +1060,12 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                continue;
                                        }
                                        peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_msg[..]));
-                                       peers.peers_needing_send.insert((*descriptor).clone());
                                }
                        },
                        wire::Message::ChannelUpdate(ref msg) => {
                                let encoded_msg = encode_msg!(msg);
 
-                               for (ref descriptor, ref mut peer) in peers.peers.iter_mut() {
+                               for (_, peer) in peers.peers.iter_mut() {
                                        if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
                                                        !peer.should_forward_channel_announcement(msg.contents.short_channel_id)  {
                                                continue
@@ -1085,7 +1077,6 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                continue;
                                        }
                                        peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_msg[..]));
-                                       peers.peers_needing_send.insert((*descriptor).clone());
                                }
                        },
                        _ => debug_assert!(false, "We shouldn't attempt to forward anything but gossip messages"),
@@ -1132,17 +1123,15 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                log_trace!(self.logger, "Handling SendAcceptChannel event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.temporary_channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendOpenChannel { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendOpenChannel event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.temporary_channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendFundingCreated { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendFundingCreated event in peer_handler for node {} for channel {} (which becomes {})",
@@ -1151,33 +1140,29 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                                log_funding_channel_id!(msg.funding_txid, msg.funding_output_index));
                                                // TODO: If the peer is gone we should generate a DiscardFunding event
                                                // indicating to the wallet that they should just throw away this funding transaction
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendFundingSigned { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendFundingSigned event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendFundingLocked { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendFundingLocked event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendAnnouncementSignatures { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendAnnouncementSignatures event in peer_handler for node {} for channel {})",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::UpdateHTLCs { ref node_id, updates: msgs::CommitmentUpdate { ref update_add_htlcs, ref update_fulfill_htlcs, ref update_fail_htlcs, ref update_fail_malformed_htlcs, ref update_fee, ref commitment_signed } } => {
                                                log_trace!(self.logger, "Handling UpdateHTLCs event in peer_handler for node {} with {} adds, {} fulfills, {} fails for channel {}",
@@ -1186,7 +1171,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                                update_fulfill_htlcs.len(),
                                                                update_fail_htlcs.len(),
                                                                log_bytes!(commitment_signed.channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                for msg in update_add_htlcs {
                                                        peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
                                                }
@@ -1203,39 +1188,34 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                        peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
                                                }
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(commitment_signed)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendRevokeAndACK { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendRevokeAndACK event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendClosingSigned { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendClosingSigned event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendShutdown { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling Shutdown event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendChannelReestablish { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendChannelReestablish event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::BroadcastChannelAnnouncement { msg, update_msg } => {
                                                log_trace!(self.logger, "Handling BroadcastChannelAnnouncement event in peer_handler for short channel id {}", msg.contents.short_channel_id);
@@ -1263,7 +1243,6 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                match *action {
                                                        msgs::ErrorAction::DisconnectPeer { ref msg } => {
                                                                if let Some(mut descriptor) = peers.node_id_to_descriptor.remove(node_id) {
-                                                                       peers.peers_needing_send.remove(&descriptor);
                                                                        if let Some(mut peer) = peers.peers.remove(&descriptor) {
                                                                                if let Some(ref msg) = *msg {
                                                                                        log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {} with message {}",
@@ -1286,21 +1265,18 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                                log_trace!(self.logger, "Handling SendErrorMessage HandleError event in peer_handler for node {} with message {}",
                                                                                log_pubkey!(node_id),
                                                                                msg.data);
-                                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                                               self.do_attempt_write_data(&mut descriptor, peer);
                                                        },
                                                }
                                        },
                                        MessageSendEvent::SendChannelRangeQuery { ref node_id, ref msg } => {
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        },
                                        MessageSendEvent::SendShortIdsQuery { ref node_id, ref msg } => {
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        }
                                        MessageSendEvent::SendReplyChannelRange { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendReplyChannelRange event in peer_handler for node {} with num_scids={} first_blocknum={} number_of_blocks={}, sync_complete={}",
@@ -1309,18 +1285,14 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                                                        msg.first_blocknum,
                                                        msg.number_of_blocks,
                                                        msg.sync_complete);
-                                               let (mut descriptor, peer) = get_peer_for_forwarding!(node_id);
+                                               let (_, peer) = get_peer_for_forwarding!(node_id);
                                                peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
-                                               self.do_attempt_write_data(&mut descriptor, peer);
                                        }
                                }
                        }
 
-                       for mut descriptor in peers.peers_needing_send.drain() {
-                               match peers.peers.get_mut(&descriptor) {
-                                       Some(peer) => self.do_attempt_write_data(&mut descriptor, peer),
-                                       None => panic!("Inconsistent peers set state!"),
-                               }
+                       for (descriptor, peer) in peers.peers.iter_mut() {
+                               self.do_attempt_write_data(&mut (*descriptor).clone(), peer);
                        }
                }
        }
@@ -1339,7 +1311,6 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
 
        fn disconnect_event_internal(&self, descriptor: &Descriptor, no_connection_possible: bool) {
                let mut peers = self.peers.lock().unwrap();
-               peers.peers_needing_send.remove(descriptor);
                let peer_option = peers.peers.remove(descriptor);
                match peer_option {
                        None => panic!("Descriptor for disconnect_event is not already known to PeerManager"),
@@ -1367,7 +1338,6 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                if let Some(mut descriptor) = peers_lock.node_id_to_descriptor.remove(&node_id) {
                        log_trace!(self.logger, "Disconnecting peer with id {} due to client request", node_id);
                        peers_lock.peers.remove(&descriptor);
-                       peers_lock.peers_needing_send.remove(&descriptor);
                        self.message_handler.chan_handler.peer_disconnected(&node_id, no_connection_possible);
                        descriptor.disconnect_socket();
                }
@@ -1381,14 +1351,12 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<D
                let mut peers_lock = self.peers.lock().unwrap();
                {
                        let peers = &mut *peers_lock;
-                       let peers_needing_send = &mut peers.peers_needing_send;
                        let node_id_to_descriptor = &mut peers.node_id_to_descriptor;
                        let peers = &mut peers.peers;
                        let mut descriptors_needing_disconnect = Vec::new();
 
                        peers.retain(|descriptor, peer| {
                                if peer.awaiting_pong {
-                                       peers_needing_send.remove(descriptor);
                                        descriptors_needing_disconnect.push(descriptor.clone());
                                        match peer.their_node_id {
                                                Some(node_id) => {