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- package autopilot
- import (
- "bytes"
- "fmt"
- "math/rand"
- "net"
- "sync"
- "time"
- "github.com/btcsuite/btcd/btcec/v2"
- "github.com/btcsuite/btcd/btcutil"
- "github.com/davecgh/go-spew/spew"
- "github.com/lightningnetwork/lnd/lnwire"
- )
- // Config couples all the items that an autopilot agent needs to function.
- // All items within the struct MUST be populated for the Agent to be able to
- // carry out its duties.
- type Config struct {
- // Self is the identity public key of the Lightning Network node that
- // is being driven by the agent. This is used to ensure that we don't
- // accidentally attempt to open a channel with ourselves.
- Self *btcec.PublicKey
- // Heuristic is an attachment heuristic which will govern to whom we
- // open channels to, and also what those channels look like in terms of
- // desired capacity. The Heuristic will take into account the current
- // state of the graph, our set of open channels, and the amount of
- // available funds when determining how channels are to be opened.
- // Additionally, a heuristic make also factor in extra-graph
- // information in order to make more pertinent recommendations.
- Heuristic AttachmentHeuristic
- // ChanController is an interface that is able to directly manage the
- // creation, closing and update of channels within the network.
- ChanController ChannelController
- // ConnectToPeer attempts to connect to the peer using one of its
- // advertised addresses. The boolean returned signals whether the peer
- // was already connected.
- ConnectToPeer func(*btcec.PublicKey, []net.Addr) (bool, error)
- // DisconnectPeer attempts to disconnect the peer with the given public
- // key.
- DisconnectPeer func(*btcec.PublicKey) error
- // WalletBalance is a function closure that should return the current
- // available balance of the backing wallet.
- WalletBalance func() (btcutil.Amount, error)
- // Graph is an abstract channel graph that the Heuristic and the Agent
- // will use to make decisions w.r.t channel allocation and placement
- // within the graph.
- Graph ChannelGraph
- // Constraints is the set of constraints the autopilot must adhere to
- // when opening channels.
- Constraints AgentConstraints
- // TODO(roasbeef): add additional signals from fee rates and revenue of
- // currently opened channels
- }
- // channelState is a type that represents the set of active channels of the
- // backing LN node that the Agent should be aware of. This type contains a few
- // helper utility methods.
- type channelState map[lnwire.ShortChannelID]LocalChannel
- // Channels returns a slice of all the active channels.
- func (c channelState) Channels() []LocalChannel {
- chans := make([]LocalChannel, 0, len(c))
- for _, channel := range c {
- chans = append(chans, channel)
- }
- return chans
- }
- // ConnectedNodes returns the set of nodes we currently have a channel with.
- // This information is needed as we want to avoid making repeated channels with
- // any node.
- func (c channelState) ConnectedNodes() map[NodeID]struct{} {
- nodes := make(map[NodeID]struct{})
- for _, channels := range c {
- nodes[channels.Node] = struct{}{}
- }
- // TODO(roasbeef): add outgoing, nodes, allow incoming and outgoing to
- // per node
- // * only add node is chan as funding amt set
- return nodes
- }
- // Agent implements a closed-loop control system which seeks to autonomously
- // optimize the allocation of satoshis within channels throughput the network's
- // channel graph. An agent is configurable by swapping out different
- // AttachmentHeuristic strategies. The agent uses external signals such as the
- // wallet balance changing, or new channels being opened/closed for the local
- // node as an indicator to re-examine its internal state, and the amount of
- // available funds in order to make updated decisions w.r.t the channel graph.
- // The Agent will automatically open, close, and splice in/out channel as
- // necessary for it to step closer to its optimal state.
- //
- // TODO(roasbeef): prob re-word
- type Agent struct {
- started sync.Once
- stopped sync.Once
- // cfg houses the configuration state of the Ant.
- cfg Config
- // chanState tracks the current set of open channels.
- chanState channelState
- chanStateMtx sync.Mutex
- // stateUpdates is a channel that any external state updates that may
- // affect the heuristics of the agent will be sent over.
- stateUpdates chan interface{}
- // balanceUpdates is a channel where notifications about updates to the
- // wallet's balance will be sent. This channel will be buffered to
- // ensure we have at most one pending update of this type to handle at
- // a given time.
- balanceUpdates chan *balanceUpdate
- // nodeUpdates is a channel that changes to the graph node landscape
- // will be sent over. This channel will be buffered to ensure we have
- // at most one pending update of this type to handle at a given time.
- nodeUpdates chan *nodeUpdates
- // pendingOpenUpdates is a channel where updates about channel pending
- // opening will be sent. This channel will be buffered to ensure we
- // have at most one pending update of this type to handle at a given
- // time.
- pendingOpenUpdates chan *chanPendingOpenUpdate
- // chanOpenFailures is a channel where updates about channel open
- // failures will be sent. This channel will be buffered to ensure we
- // have at most one pending update of this type to handle at a given
- // time.
- chanOpenFailures chan *chanOpenFailureUpdate
- // heuristicUpdates is a channel where updates from active heuristics
- // will be sent.
- heuristicUpdates chan *heuristicUpdate
- // totalBalance is the total number of satoshis the backing wallet is
- // known to control at any given instance. This value will be updated
- // when the agent receives external balance update signals.
- totalBalance btcutil.Amount
- // failedNodes lists nodes that we've previously attempted to initiate
- // channels with, but didn't succeed.
- failedNodes map[NodeID]struct{}
- // pendingConns tracks the nodes that we are attempting to make
- // connections to. This prevents us from making duplicate connection
- // requests to the same node.
- pendingConns map[NodeID]struct{}
- // pendingOpens tracks the channels that we've requested to be
- // initiated, but haven't yet been confirmed as being fully opened.
- // This state is required as otherwise, we may go over our allotted
- // channel limit, or open multiple channels to the same node.
- pendingOpens map[NodeID]LocalChannel
- pendingMtx sync.Mutex
- quit chan struct{}
- wg sync.WaitGroup
- }
- // New creates a new instance of the Agent instantiated using the passed
- // configuration and initial channel state. The initial channel state slice
- // should be populated with the set of Channels that are currently opened by
- // the backing Lightning Node.
- func New(cfg Config, initialState []LocalChannel) (*Agent, error) {
- a := &Agent{
- cfg: cfg,
- chanState: make(map[lnwire.ShortChannelID]LocalChannel),
- quit: make(chan struct{}),
- stateUpdates: make(chan interface{}),
- balanceUpdates: make(chan *balanceUpdate, 1),
- nodeUpdates: make(chan *nodeUpdates, 1),
- chanOpenFailures: make(chan *chanOpenFailureUpdate, 1),
- heuristicUpdates: make(chan *heuristicUpdate, 1),
- pendingOpenUpdates: make(chan *chanPendingOpenUpdate, 1),
- failedNodes: make(map[NodeID]struct{}),
- pendingConns: make(map[NodeID]struct{}),
- pendingOpens: make(map[NodeID]LocalChannel),
- }
- for _, c := range initialState {
- a.chanState[c.ChanID] = c
- }
- return a, nil
- }
- // Start starts the agent along with any goroutines it needs to perform its
- // normal duties.
- func (a *Agent) Start() error {
- var err error
- a.started.Do(func() {
- err = a.start()
- })
- return err
- }
- func (a *Agent) start() error {
- rand.Seed(time.Now().Unix())
- log.Infof("Autopilot Agent starting")
- a.wg.Add(1)
- go a.controller()
- return nil
- }
- // Stop signals the Agent to gracefully shutdown. This function will block
- // until all goroutines have exited.
- func (a *Agent) Stop() error {
- var err error
- a.stopped.Do(func() {
- err = a.stop()
- })
- return err
- }
- func (a *Agent) stop() error {
- log.Infof("Autopilot Agent stopping")
- close(a.quit)
- a.wg.Wait()
- return nil
- }
- // balanceUpdate is a type of external state update that reflects an
- // increase/decrease in the funds currently available to the wallet.
- type balanceUpdate struct {
- }
- // nodeUpdates is a type of external state update that reflects an addition or
- // modification in channel graph node membership.
- type nodeUpdates struct{}
- // chanOpenUpdate is a type of external state update that indicates a new
- // channel has been opened, either by the Agent itself (within the main
- // controller loop), or by an external user to the system.
- type chanOpenUpdate struct {
- newChan LocalChannel
- }
- // chanPendingOpenUpdate is a type of external state update that indicates a new
- // channel has been opened, either by the agent itself or an external subsystem,
- // but is still pending.
- type chanPendingOpenUpdate struct{}
- // chanOpenFailureUpdate is a type of external state update that indicates
- // a previous channel open failed, and that it might be possible to try again.
- type chanOpenFailureUpdate struct{}
- // heuristicUpdate is an update sent when one of the autopilot heuristics has
- // changed, and prompts the agent to make a new attempt at opening more
- // channels.
- type heuristicUpdate struct {
- heuristic AttachmentHeuristic
- }
- // chanCloseUpdate is a type of external state update that indicates that the
- // backing Lightning Node has closed a previously open channel.
- type chanCloseUpdate struct {
- closedChans []lnwire.ShortChannelID
- }
- // OnBalanceChange is a callback that should be executed each time the balance
- // of the backing wallet changes.
- func (a *Agent) OnBalanceChange() {
- select {
- case a.balanceUpdates <- &balanceUpdate{}:
- default:
- }
- }
- // OnNodeUpdates is a callback that should be executed each time our channel
- // graph has new nodes or their node announcements are updated.
- func (a *Agent) OnNodeUpdates() {
- select {
- case a.nodeUpdates <- &nodeUpdates{}:
- default:
- }
- }
- // OnChannelOpen is a callback that should be executed each time a new channel
- // is manually opened by the user or any system outside the autopilot agent.
- func (a *Agent) OnChannelOpen(c LocalChannel) {
- a.wg.Add(1)
- go func() {
- defer a.wg.Done()
- select {
- case a.stateUpdates <- &chanOpenUpdate{newChan: c}:
- case <-a.quit:
- }
- }()
- }
- // OnChannelPendingOpen is a callback that should be executed each time a new
- // channel is opened, either by the agent or an external subsystems, but is
- // still pending.
- func (a *Agent) OnChannelPendingOpen() {
- select {
- case a.pendingOpenUpdates <- &chanPendingOpenUpdate{}:
- default:
- }
- }
- // OnChannelOpenFailure is a callback that should be executed when the
- // autopilot has attempted to open a channel, but failed. In this case we can
- // retry channel creation with a different node.
- func (a *Agent) OnChannelOpenFailure() {
- select {
- case a.chanOpenFailures <- &chanOpenFailureUpdate{}:
- default:
- }
- }
- // OnChannelClose is a callback that should be executed each time a prior
- // channel has been closed for any reason. This includes regular
- // closes, force closes, and channel breaches.
- func (a *Agent) OnChannelClose(closedChans ...lnwire.ShortChannelID) {
- a.wg.Add(1)
- go func() {
- defer a.wg.Done()
- select {
- case a.stateUpdates <- &chanCloseUpdate{closedChans: closedChans}:
- case <-a.quit:
- }
- }()
- }
- // OnHeuristicUpdate is a method called when a heuristic has been updated, to
- // trigger the agent to do a new state assessment.
- func (a *Agent) OnHeuristicUpdate(h AttachmentHeuristic) {
- select {
- case a.heuristicUpdates <- &heuristicUpdate{
- heuristic: h,
- }:
- default:
- }
- }
- // mergeNodeMaps merges the Agent's set of nodes that it already has active
- // channels open to, with the other sets of nodes that should be removed from
- // consideration during heuristic selection. This ensures that the Agent doesn't
- // attempt to open any "duplicate" channels to the same node.
- func mergeNodeMaps(c map[NodeID]LocalChannel,
- skips ...map[NodeID]struct{}) map[NodeID]struct{} {
- numNodes := len(c)
- for _, skip := range skips {
- numNodes += len(skip)
- }
- res := make(map[NodeID]struct{}, numNodes)
- for nodeID := range c {
- res[nodeID] = struct{}{}
- }
- for _, skip := range skips {
- for nodeID := range skip {
- res[nodeID] = struct{}{}
- }
- }
- return res
- }
- // mergeChanState merges the Agent's set of active channels, with the set of
- // channels awaiting confirmation. This ensures that the agent doesn't go over
- // the prescribed channel limit or fund allocation limit.
- func mergeChanState(pendingChans map[NodeID]LocalChannel,
- activeChans channelState) []LocalChannel {
- numChans := len(pendingChans) + len(activeChans)
- totalChans := make([]LocalChannel, 0, numChans)
- totalChans = append(totalChans, activeChans.Channels()...)
- for _, pendingChan := range pendingChans {
- totalChans = append(totalChans, pendingChan)
- }
- return totalChans
- }
- // controller implements the closed-loop control system of the Agent. The
- // controller will make a decision w.r.t channel placement within the graph
- // based on: its current internal state of the set of active channels open,
- // and external state changes as a result of decisions it makes w.r.t channel
- // allocation, or attributes affecting its control loop being updated by the
- // backing Lightning Node.
- func (a *Agent) controller() {
- defer a.wg.Done()
- // We'll start off by assigning our starting balance, and injecting
- // that amount as an initial wake up to the main controller goroutine.
- a.OnBalanceChange()
- // TODO(roasbeef): do we in fact need to maintain order?
- // * use sync.Cond if so
- updateBalance := func() {
- newBalance, err := a.cfg.WalletBalance()
- if err != nil {
- log.Warnf("unable to update wallet balance: %v", err)
- return
- }
- a.totalBalance = newBalance
- }
- // TODO(roasbeef): add 10-minute wake up timer
- for {
- select {
- // A new external signal has arrived. We'll use this to update
- // our internal state, then determine if we should trigger a
- // channel state modification (open/close, splice in/out).
- case signal := <-a.stateUpdates:
- log.Infof("Processing new external signal")
- switch update := signal.(type) {
- // A new channel has been opened successfully. This was
- // either opened by the Agent, or an external system
- // that is able to drive the Lightning Node.
- case *chanOpenUpdate:
- log.Debugf("New channel successfully opened, "+
- "updating state with: %v",
- spew.Sdump(update.newChan))
- newChan := update.newChan
- a.chanStateMtx.Lock()
- a.chanState[newChan.ChanID] = newChan
- a.chanStateMtx.Unlock()
- a.pendingMtx.Lock()
- delete(a.pendingOpens, newChan.Node)
- a.pendingMtx.Unlock()
- updateBalance()
- // A channel has been closed, this may free up an
- // available slot, triggering a new channel update.
- case *chanCloseUpdate:
- log.Debugf("Applying closed channel "+
- "updates: %v",
- spew.Sdump(update.closedChans))
- a.chanStateMtx.Lock()
- for _, closedChan := range update.closedChans {
- delete(a.chanState, closedChan)
- }
- a.chanStateMtx.Unlock()
- updateBalance()
- }
- // A new channel has been opened by the agent or an external
- // subsystem, but is still pending confirmation.
- case <-a.pendingOpenUpdates:
- updateBalance()
- // The balance of the backing wallet has changed, if more funds
- // are now available, we may attempt to open up an additional
- // channel, or splice in funds to an existing one.
- case <-a.balanceUpdates:
- log.Debug("Applying external balance state update")
- updateBalance()
- // The channel we tried to open previously failed for whatever
- // reason.
- case <-a.chanOpenFailures:
- log.Debug("Retrying after previous channel open " +
- "failure.")
- updateBalance()
- // New nodes have been added to the graph or their node
- // announcements have been updated. We will consider opening
- // channels to these nodes if we haven't stabilized.
- case <-a.nodeUpdates:
- log.Debugf("Node updates received, assessing " +
- "need for more channels")
- // Any of the deployed heuristics has been updated, check
- // whether we have new channel candidates available.
- case upd := <-a.heuristicUpdates:
- log.Debugf("Heuristic %v updated, assessing need for "+
- "more channels", upd.heuristic.Name())
- // The agent has been signalled to exit, so we'll bail out
- // immediately.
- case <-a.quit:
- return
- }
- a.pendingMtx.Lock()
- log.Debugf("Pending channels: %v", spew.Sdump(a.pendingOpens))
- a.pendingMtx.Unlock()
- // With all the updates applied, we'll obtain a set of the
- // current active channels (confirmed channels), and also
- // factor in our set of unconfirmed channels.
- a.chanStateMtx.Lock()
- a.pendingMtx.Lock()
- totalChans := mergeChanState(a.pendingOpens, a.chanState)
- a.pendingMtx.Unlock()
- a.chanStateMtx.Unlock()
- // Now that we've updated our internal state, we'll consult our
- // channel attachment heuristic to determine if we can open
- // up any additional channels while staying within our
- // constraints.
- availableFunds, numChans := a.cfg.Constraints.ChannelBudget(
- totalChans, a.totalBalance,
- )
- switch {
- case numChans == 0:
- continue
- // If the amount is too small, we don't want to attempt opening
- // another channel.
- case availableFunds == 0:
- continue
- case availableFunds < a.cfg.Constraints.MinChanSize():
- continue
- }
- log.Infof("Triggering attachment directive dispatch, "+
- "total_funds=%v", a.totalBalance)
- err := a.openChans(availableFunds, numChans, totalChans)
- if err != nil {
- log.Errorf("Unable to open channels: %v", err)
- }
- }
- }
- // openChans queries the agent's heuristic for a set of channel candidates, and
- // attempts to open channels to them.
- func (a *Agent) openChans(availableFunds btcutil.Amount, numChans uint32,
- totalChans []LocalChannel) error {
- // As channel size we'll use the maximum channel size available.
- chanSize := a.cfg.Constraints.MaxChanSize()
- if availableFunds < chanSize {
- chanSize = availableFunds
- }
- if chanSize < a.cfg.Constraints.MinChanSize() {
- return fmt.Errorf("not enough funds available to open a " +
- "single channel")
- }
- // We're to attempt an attachment so we'll obtain the set of
- // nodes that we currently have channels with so we avoid
- // duplicate edges.
- a.chanStateMtx.Lock()
- connectedNodes := a.chanState.ConnectedNodes()
- a.chanStateMtx.Unlock()
- for nID := range connectedNodes {
- log.Tracef("Skipping node %x with open channel", nID[:])
- }
- a.pendingMtx.Lock()
- for nID := range a.pendingOpens {
- log.Tracef("Skipping node %x with pending channel open", nID[:])
- }
- for nID := range a.pendingConns {
- log.Tracef("Skipping node %x with pending connection", nID[:])
- }
- for nID := range a.failedNodes {
- log.Tracef("Skipping failed node %v", nID[:])
- }
- nodesToSkip := mergeNodeMaps(a.pendingOpens,
- a.pendingConns, connectedNodes, a.failedNodes,
- )
- a.pendingMtx.Unlock()
- // Gather the set of all nodes in the graph, except those we
- // want to skip.
- selfPubBytes := a.cfg.Self.SerializeCompressed()
- nodes := make(map[NodeID]struct{})
- addresses := make(map[NodeID][]net.Addr)
- if err := a.cfg.Graph.ForEachNode(func(node Node) error {
- nID := NodeID(node.PubKey())
- // If we come across ourselves, them we'll continue in
- // order to avoid attempting to make a channel with
- // ourselves.
- if bytes.Equal(nID[:], selfPubBytes) {
- log.Tracef("Skipping self node %x", nID[:])
- return nil
- }
- // If the node has no known addresses, we cannot connect to it,
- // so we'll skip it.
- addrs := node.Addrs()
- if len(addrs) == 0 {
- log.Tracef("Skipping node %x since no addresses known",
- nID[:])
- return nil
- }
- addresses[nID] = addrs
- // Additionally, if this node is in the blacklist, then
- // we'll skip it.
- if _, ok := nodesToSkip[nID]; ok {
- log.Tracef("Skipping blacklisted node %x", nID[:])
- return nil
- }
- nodes[nID] = struct{}{}
- return nil
- }); err != nil {
- return fmt.Errorf("unable to get graph nodes: %w", err)
- }
- // Use the heuristic to calculate a score for each node in the
- // graph.
- log.Debugf("Scoring %d nodes for chan_size=%v", len(nodes), chanSize)
- scores, err := a.cfg.Heuristic.NodeScores(
- a.cfg.Graph, totalChans, chanSize, nodes,
- )
- if err != nil {
- return fmt.Errorf("unable to calculate node scores : %w", err)
- }
- log.Debugf("Got scores for %d nodes", len(scores))
- // Now use the score to make a weighted choice which nodes to attempt
- // to open channels to.
- scores, err = chooseN(numChans, scores)
- if err != nil {
- return fmt.Errorf("unable to make weighted choice: %w",
- err)
- }
- chanCandidates := make(map[NodeID]*AttachmentDirective)
- for nID := range scores {
- log.Tracef("Creating attachment directive for chosen node %x",
- nID[:])
- // Track the available funds we have left.
- if availableFunds < chanSize {
- chanSize = availableFunds
- }
- availableFunds -= chanSize
- // If we run out of funds, we can break early.
- if chanSize < a.cfg.Constraints.MinChanSize() {
- log.Tracef("Chan size %v too small to satisfy min "+
- "channel size %v, breaking", chanSize,
- a.cfg.Constraints.MinChanSize())
- break
- }
- chanCandidates[nID] = &AttachmentDirective{
- NodeID: nID,
- ChanAmt: chanSize,
- Addrs: addresses[nID],
- }
- }
- if len(chanCandidates) == 0 {
- log.Infof("No eligible candidates to connect to")
- return nil
- }
- log.Infof("Attempting to execute channel attachment "+
- "directives: %v", spew.Sdump(chanCandidates))
- // Before proceeding, check to see if we have any slots
- // available to open channels. If there are any, we will attempt
- // to dispatch the retrieved directives since we can't be
- // certain which ones may actually succeed. If too many
- // connections succeed, they will be ignored and made
- // available to future heuristic selections.
- a.pendingMtx.Lock()
- defer a.pendingMtx.Unlock()
- if uint16(len(a.pendingOpens)) >= a.cfg.Constraints.MaxPendingOpens() {
- log.Debugf("Reached cap of %v pending "+
- "channel opens, will retry "+
- "after success/failure",
- a.cfg.Constraints.MaxPendingOpens())
- return nil
- }
- // For each recommended attachment directive, we'll launch a
- // new goroutine to attempt to carry out the directive. If any
- // of these succeed, then we'll receive a new state update,
- // taking us back to the top of our controller loop.
- for _, chanCandidate := range chanCandidates {
- // Skip candidates which we are already trying
- // to establish a connection with.
- nodeID := chanCandidate.NodeID
- if _, ok := a.pendingConns[nodeID]; ok {
- continue
- }
- a.pendingConns[nodeID] = struct{}{}
- a.wg.Add(1)
- go a.executeDirective(*chanCandidate)
- }
- return nil
- }
- // executeDirective attempts to connect to the channel candidate specified by
- // the given attachment directive, and open a channel of the given size.
- //
- // NOTE: MUST be run as a goroutine.
- func (a *Agent) executeDirective(directive AttachmentDirective) {
- defer a.wg.Done()
- // We'll start out by attempting to connect to the peer in order to
- // begin the funding workflow.
- nodeID := directive.NodeID
- pub, err := btcec.ParsePubKey(nodeID[:])
- if err != nil {
- log.Errorf("Unable to parse pubkey %x: %v", nodeID, err)
- return
- }
- connected := make(chan bool)
- errChan := make(chan error)
- // To ensure a call to ConnectToPeer doesn't block the agent from
- // shutting down, we'll launch it in a non-waitgrouped goroutine, that
- // will signal when a result is returned.
- // TODO(halseth): use DialContext to cancel on transport level.
- go func() {
- alreadyConnected, err := a.cfg.ConnectToPeer(
- pub, directive.Addrs,
- )
- if err != nil {
- select {
- case errChan <- err:
- case <-a.quit:
- }
- return
- }
- select {
- case connected <- alreadyConnected:
- case <-a.quit:
- return
- }
- }()
- var alreadyConnected bool
- select {
- case alreadyConnected = <-connected:
- case err = <-errChan:
- case <-a.quit:
- return
- }
- if err != nil {
- log.Warnf("Unable to connect to %x: %v",
- pub.SerializeCompressed(), err)
- // Since we failed to connect to them, we'll mark them as
- // failed so that we don't attempt to connect to them again.
- a.pendingMtx.Lock()
- delete(a.pendingConns, nodeID)
- a.failedNodes[nodeID] = struct{}{}
- a.pendingMtx.Unlock()
- // Finally, we'll trigger the agent to select new peers to
- // connect to.
- a.OnChannelOpenFailure()
- return
- }
- // The connection was successful, though before progressing we must
- // check that we have not already met our quota for max pending open
- // channels. This can happen if multiple directives were spawned but
- // fewer slots were available, and other successful attempts finished
- // first.
- a.pendingMtx.Lock()
- if uint16(len(a.pendingOpens)) >= a.cfg.Constraints.MaxPendingOpens() {
- // Since we've reached our max number of pending opens, we'll
- // disconnect this peer and exit. However, if we were
- // previously connected to them, then we'll make sure to
- // maintain the connection alive.
- if alreadyConnected {
- // Since we succeeded in connecting, we won't add this
- // peer to the failed nodes map, but we will remove it
- // from a.pendingConns so that it can be retried in the
- // future.
- delete(a.pendingConns, nodeID)
- a.pendingMtx.Unlock()
- return
- }
- err = a.cfg.DisconnectPeer(pub)
- if err != nil {
- log.Warnf("Unable to disconnect peer %x: %v",
- pub.SerializeCompressed(), err)
- }
- // Now that we have disconnected, we can remove this node from
- // our pending conns map, permitting subsequent connection
- // attempts.
- delete(a.pendingConns, nodeID)
- a.pendingMtx.Unlock()
- return
- }
- // If we were successful, we'll track this peer in our set of pending
- // opens. We do this here to ensure we don't stall on selecting new
- // peers if the connection attempt happens to take too long.
- delete(a.pendingConns, nodeID)
- a.pendingOpens[nodeID] = LocalChannel{
- Balance: directive.ChanAmt,
- Node: nodeID,
- }
- a.pendingMtx.Unlock()
- // We can then begin the funding workflow with this peer.
- err = a.cfg.ChanController.OpenChannel(pub, directive.ChanAmt)
- if err != nil {
- log.Warnf("Unable to open channel to %x of %v: %v",
- pub.SerializeCompressed(), directive.ChanAmt, err)
- // As the attempt failed, we'll clear the peer from the set of
- // pending opens and mark them as failed so we don't attempt to
- // open a channel to them again.
- a.pendingMtx.Lock()
- delete(a.pendingOpens, nodeID)
- a.failedNodes[nodeID] = struct{}{}
- a.pendingMtx.Unlock()
- // Trigger the agent to re-evaluate everything and possibly
- // retry with a different node.
- a.OnChannelOpenFailure()
- // Finally, we should also disconnect the peer if we weren't
- // already connected to them beforehand by an external
- // subsystem.
- if alreadyConnected {
- return
- }
- err = a.cfg.DisconnectPeer(pub)
- if err != nil {
- log.Warnf("Unable to disconnect peer %x: %v",
- pub.SerializeCompressed(), err)
- }
- }
- // Since the channel open was successful and is currently pending,
- // we'll trigger the autopilot agent to query for more peers.
- // TODO(halseth): this triggers a new loop before all the new channels
- // are added to the pending channels map. Should add before executing
- // directive in goroutine?
- a.OnChannelPendingOpen()
- }
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