/// the peer.
const OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP: usize = OUTBOUND_BUFFER_LIMIT_READ_PAUSE * FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO;
+/// If we've sent a ping, and are still awaiting a response, we may need to churn our way through
+/// the socket receive buffer before receiving the ping.
+///
+/// On a fairly old Arm64 board, with Linux defaults, this can take as long as 20 seconds, not
+/// including any network delays, outbound traffic, or the same for messages from other peers.
+///
+/// Thus, to avoid needlessly disconnecting a peer, we allow a peer to take this many timer ticks
+/// per connected peer to respond to a ping, as long as they send us at least one message during
+/// each tick, ensuring we aren't actually just disconnected.
+/// With a timer tick interval of five seconds, this translates to about 30 seconds per connected
+/// peer.
+///
+/// When we improve parallelism somewhat we should reduce this to e.g. this many timer ticks per
+/// two connected peers, assuming most LDK-running systems have at least two cores.
+const MAX_BUFFER_DRAIN_TICK_INTERVALS_PER_PEER: i8 = 6;
+
+/// This is the minimum number of messages we expect a peer to be able to handle within one timer
+/// tick. Once we have sent this many messages since the last ping, we send a ping right away to
+/// ensures we don't just fill up our send buffer and leave the peer with too many messages to
+/// process before the next ping.
+const BUFFER_DRAIN_MSGS_PER_TICK: usize = 32;
+
struct Peer {
channel_encryptor: PeerChannelEncryptor,
their_node_id: Option<PublicKey>,
sync_status: InitSyncTracker,
- awaiting_pong: bool,
+ msgs_sent_since_pong: usize,
+ awaiting_pong_timer_tick_intervals: i8,
+ received_message_since_timer_tick: bool,
}
impl Peer {
sync_status: InitSyncTracker::NoSyncRequested,
- awaiting_pong: false,
+ msgs_sent_since_pong: 0,
+ awaiting_pong_timer_tick_intervals: 0,
+ received_message_since_timer_tick: false,
}).is_some() {
panic!("PeerManager driver duplicated descriptors!");
};
sync_status: InitSyncTracker::NoSyncRequested,
- awaiting_pong: false,
+ msgs_sent_since_pong: 0,
+ awaiting_pong_timer_tick_intervals: 0,
+ received_message_since_timer_tick: false,
}).is_some() {
panic!("PeerManager driver duplicated descriptors!");
};
fn do_attempt_write_data(&self, descriptor: &mut Descriptor, peer: &mut Peer) {
while !peer.awaiting_write_event {
- if peer.pending_outbound_buffer.len() < OUTBOUND_BUFFER_LIMIT_READ_PAUSE {
+ if peer.pending_outbound_buffer.len() < OUTBOUND_BUFFER_LIMIT_READ_PAUSE && peer.msgs_sent_since_pong < BUFFER_DRAIN_MSGS_PER_TICK {
match peer.sync_status {
InitSyncTracker::NoSyncRequested => {},
InitSyncTracker::ChannelsSyncing(c) if c < 0xffff_ffff_ffff_ffff => {
},
}
}
+ if peer.msgs_sent_since_pong >= BUFFER_DRAIN_MSGS_PER_TICK {
+ self.maybe_send_extra_ping(peer);
+ }
if {
let next_buff = match peer.pending_outbound_buffer.front() {
/// Append a message to a peer's pending outbound/write buffer
fn enqueue_encoded_message(&self, peer: &mut Peer, encoded_message: &Vec<u8>) {
+ peer.msgs_sent_since_pong += 1;
peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_message[..]));
}
message: wire::Message<<<CMH as core::ops::Deref>::Target as wire::CustomMessageReader>::CustomMessage>
) -> Result<Option<wire::Message<<<CMH as core::ops::Deref>::Target as wire::CustomMessageReader>::CustomMessage>>, MessageHandlingError> {
log_trace!(self.logger, "Received message {:?} from {}", message, log_pubkey!(peer.their_node_id.unwrap()));
+ peer.received_message_since_timer_tick = true;
// Need an Init as first message
if let wire::Message::Init(_) = message {
}
},
wire::Message::Pong(_msg) => {
- peer.awaiting_pong = false;
+ peer.awaiting_pong_timer_tick_intervals = 0;
+ peer.msgs_sent_since_pong = 0;
},
// Channel messages:
!peer.should_forward_channel_announcement(msg.contents.short_channel_id) {
continue
}
- if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP {
+ if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP
+ || peer.msgs_sent_since_pong > BUFFER_DRAIN_MSGS_PER_TICK * FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO
+ {
log_trace!(self.logger, "Skipping broadcast message to {:?} as its outbound buffer is full", peer.their_node_id);
continue;
}
!peer.should_forward_node_announcement(msg.contents.node_id) {
continue
}
- if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP {
+ if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP
+ || peer.msgs_sent_since_pong > BUFFER_DRAIN_MSGS_PER_TICK * FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO
+ {
log_trace!(self.logger, "Skipping broadcast message to {:?} as its outbound buffer is full", peer.their_node_id);
continue;
}
!peer.should_forward_channel_announcement(msg.contents.short_channel_id) {
continue
}
- if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP {
+ if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP
+ || peer.msgs_sent_since_pong > BUFFER_DRAIN_MSGS_PER_TICK * FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO
+ {
log_trace!(self.logger, "Skipping broadcast message to {:?} as its outbound buffer is full", peer.their_node_id);
continue;
}
debug_assert!(peers.node_id_to_descriptor.is_empty());
}
+ /// This is called when we're blocked on sending additional gossip messages until we receive a
+ /// pong. If we aren't waiting on a pong, we take this opportunity to send a ping (setting
+ /// `awaiting_pong_timer_tick_intervals` to a special flag value to indicate this).
+ fn maybe_send_extra_ping(&self, peer: &mut Peer) {
+ if peer.awaiting_pong_timer_tick_intervals == 0 {
+ peer.awaiting_pong_timer_tick_intervals = -1;
+ let ping = msgs::Ping {
+ ponglen: 0,
+ byteslen: 64,
+ };
+ self.enqueue_message(peer, &ping);
+ }
+ }
+
/// Send pings to each peer and disconnect those which did not respond to the last round of
/// pings.
///
let node_id_to_descriptor = &mut peers.node_id_to_descriptor;
let peers = &mut peers.peers;
let mut descriptors_needing_disconnect = Vec::new();
+ let peer_count = peers.len();
peers.retain(|descriptor, peer| {
- if peer.awaiting_pong {
+ if !peer.channel_encryptor.is_ready_for_encryption() {
+ // The peer needs to complete its handshake before we can exchange messages
+ return true;
+ }
+
+ 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 * peer_count as u64
+ {
descriptors_needing_disconnect.push(descriptor.clone());
match peer.their_node_id {
Some(node_id) => {
return false;
}
- if !peer.channel_encryptor.is_ready_for_encryption() {
- // The peer needs to complete its handshake before we can exchange messages
+ peer.received_message_since_timer_tick = false;
+ if peer.awaiting_pong_timer_tick_intervals == -1 {
+ // Magic value set in `maybe_send_extra_ping`.
+ peer.awaiting_pong_timer_tick_intervals = 1;
+ return true;
+ }
+
+ if peer.awaiting_pong_timer_tick_intervals > 0 {
+ peer.awaiting_pong_timer_tick_intervals += 1;
return true;
}
+ peer.awaiting_pong_timer_tick_intervals = 1;
let ping = msgs::Ping {
ponglen: 0,
byteslen: 64,
};
self.enqueue_message(peer, &ping);
+ self.do_attempt_write_data(&mut (descriptor.clone()), &mut *peer);
- let mut descriptor_clone = descriptor.clone();
- self.do_attempt_write_data(&mut descriptor_clone, peer);
-
- peer.awaiting_pong = true;
true
});
// than can fit into a peer's buffer).
let (mut fd_a, mut fd_b) = establish_connection(&peers[0], &peers[1]);
- // Make each peer to read the messages that the other peer just wrote to them.
- peers[0].process_events();
- peers[1].read_event(&mut fd_b, &fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap();
- peers[1].process_events();
- peers[0].read_event(&mut fd_a, &fd_b.outbound_data.lock().unwrap().split_off(0)).unwrap();
+ // Make each peer to read the messages that the other peer just wrote to them. Note that
+ // due to the max-messagse-before-ping limits this may take a few iterations to complete.
+ for _ in 0..150/super::BUFFER_DRAIN_MSGS_PER_TICK + 1 {
+ peers[0].process_events();
+ let b_read_data = fd_a.outbound_data.lock().unwrap().split_off(0);
+ assert!(!b_read_data.is_empty());
+
+ peers[1].read_event(&mut fd_b, &b_read_data).unwrap();
+ peers[1].process_events();
+
+ let a_read_data = fd_b.outbound_data.lock().unwrap().split_off(0);
+ assert!(!a_read_data.is_empty());
+ peers[0].read_event(&mut fd_a, &a_read_data).unwrap();
+
+ peers[1].process_events();
+ assert_eq!(fd_b.outbound_data.lock().unwrap().len(), 0, "Until B receives data, it shouldn't send more messages");
+ }
// Check that each peer has received the expected number of channel updates and channel
// announcements.
projects / rust-lightning / commitdiff