htlcswitch+peer: notify inactive link event when htlcManager exits

htlcswitch/link.go

@@ -293,6 +293,10 @@ type ChannelLinkConfig struct {
 	// when channels become inactive.
 	NotifyInactiveChannel func(wire.OutPoint)
 
+	// NotifyInactiveLinkEvent allows the switch to tell the
+	// ChannelNotifier when a channel link become inactive.
+	NotifyInactiveLinkEvent func(wire.OutPoint)
+
 	// HtlcNotifier is an instance of a htlcNotifier which we will pipe htlc
 	// events through.
 	HtlcNotifier htlcNotifier
@@ -979,8 +983,11 @@ func (l *channelLink) htlcManager() {
 	l.log.Infof("HTLC manager started, bandwidth=%v", l.Bandwidth())
 
 	// Notify any clients that the link is now in the switch via an
-	// ActiveLinkEvent.
+	// ActiveLinkEvent. We'll also defer an inactive link notification for
+	// when the link exits to ensure that every active notification is
+	// matched by an inactive one.
 	l.cfg.NotifyActiveLink(*l.ChannelPoint())
+	defer l.cfg.NotifyInactiveLinkEvent(*l.ChannelPoint())
 
 	// TODO(roasbeef): need to call wipe chan whenever D/C?
 

htlcswitch/link_test.go

@@ -1894,6 +1894,7 @@ func newSingleLinkTestHarness(t *testing.T, chanAmt, chanReserve btcutil.Amount)
 		NotifyActiveLink:        func(wire.OutPoint) {},
 		NotifyActiveChannel:     func(wire.OutPoint) {},
 		NotifyInactiveChannel:   func(wire.OutPoint) {},
+		NotifyInactiveLinkEvent: func(wire.OutPoint) {},
 		HtlcNotifier:            aliceSwitch.cfg.HtlcNotifier,
 		GetAliases:              getAliases,
 	}
@@ -4335,6 +4336,7 @@ func (h *persistentLinkHarness) restartLink(
 		NotifyActiveLink:        func(wire.OutPoint) {},
 		NotifyActiveChannel:     func(wire.OutPoint) {},
 		NotifyInactiveChannel:   func(wire.OutPoint) {},
+		NotifyInactiveLinkEvent: func(wire.OutPoint) {},
 		HtlcNotifier:            aliceSwitch.cfg.HtlcNotifier,
 		SyncStates:              syncStates,
 		GetAliases:              getAliases,

htlcswitch/switch.go

@@ -2293,6 +2293,8 @@ func (s *Switch) AddLink(link ChannelLink) error {
 	link.attachFailAliasUpdate(s.failAliasUpdate)
 
 	if err := link.Start(); err != nil {
+		log.Errorf("AddLink failed to start link with chanID=%v: %v",
+			chanID, err)
 		s.removeLink(chanID)
 		return err
 	}

htlcswitch/test_utils.go

@@ -1159,6 +1159,7 @@ func (h *hopNetwork) createChannelLink(server, peer *mockServer,
 			NotifyActiveLink:        func(wire.OutPoint) {},
 			NotifyActiveChannel:     func(wire.OutPoint) {},
 			NotifyInactiveChannel:   func(wire.OutPoint) {},
+			NotifyInactiveLinkEvent: func(wire.OutPoint) {},
 			HtlcNotifier:            server.htlcSwitch.cfg.HtlcNotifier,
 			GetAliases:              getAliases,
 		},

peer/brontide.go

@@ -941,6 +941,7 @@ func (p *Brontide) addLink(chanPoint *wire.OutPoint,
 		towerClient = p.cfg.TowerClient
 	}
 
+	//nolint:lll
 	linkCfg := htlcswitch.ChannelLinkConfig{
 		Peer:                   p,
 		DecodeHopIterators:     p.cfg.Sphinx.DecodeHopIterators,
@@ -976,6 +977,7 @@ func (p *Brontide) addLink(chanPoint *wire.OutPoint,
 		NotifyActiveLink:        p.cfg.ChannelNotifier.NotifyActiveLinkEvent,
 		NotifyActiveChannel:     p.cfg.ChannelNotifier.NotifyActiveChannelEvent,
 		NotifyInactiveChannel:   p.cfg.ChannelNotifier.NotifyInactiveChannelEvent,
+		NotifyInactiveLinkEvent: p.cfg.ChannelNotifier.NotifyInactiveLinkEvent,
 		HtlcNotifier:            p.cfg.HtlcNotifier,
 		GetAliases:              p.cfg.GetAliases,
 	}