htlcswitch: add link operation for initiating quiescence

htlcswitch/interfaces.go

@@ -170,6 +170,18 @@ type ChannelUpdateHandler interface {
 	// will only ever be called once. If no CommitSig is owed in the
 	// argument's LinkDirection, then we will call this hook immediately.
 	OnCommitOnce(LinkDirection, func())
+
+	// InitStfu allows us to initiate quiescence on this link. It returns
+	// a receive only channel that will block until quiescence has been
+	// achieved, or definitively fails. The return value is the
+	// ChannelParty who holds the role of initiator or Err if the operation
+	// fails.
+	//
+	// This operation has been added to allow channels to be quiesced via
+	// RPC. It may be removed or reworked in the future as RPC initiated
+	// quiescence is a holdover until we have downstream protocols that use
+	// it.
+	InitStfu() <-chan fn.Result[lntypes.ChannelParty]
 }
 
 // CommitHookID is a value that is used to uniquely identify hooks in the

htlcswitch/link.go

@@ -737,6 +737,22 @@ func (l *channelLink) OnCommitOnce(direction LinkDirection, hook func()) {
 	}
 }
 
+// InitStfu allows us to initiate quiescence on this link. It returns a receive
+// only channel that will block until quiescence has been achieved, or
+// definitively fails.
+//
+// This operation has been added to allow channels to be quiesced via RPC. It
+// may be removed or reworked in the future as RPC initiated quiescence is a
+// holdover until we have downstream protocols that use it.
+func (l *channelLink) InitStfu() <-chan fn.Result[lntypes.ChannelParty] {
+	// TODO(proofofkeags): Implement
+	c := make(chan fn.Result[lntypes.ChannelParty], 1)
+
+	c <- fn.Errf[lntypes.ChannelParty]("InitStfu not yet implemented")
+
+	return c
+}
+
 // isReestablished returns true if the link has successfully completed the
 // channel reestablishment dance.
 func (l *channelLink) isReestablished() bool {

htlcswitch/mock.go

@@ -950,6 +950,14 @@ func (f *mockChannelLink) OnFlushedOnce(func()) {
 func (f *mockChannelLink) OnCommitOnce(LinkDirection, func()) {
 	// TODO(proofofkeags): Implement
 }
+func (f *mockChannelLink) InitStfu() <-chan fn.Result[lntypes.ChannelParty] {
+	// TODO(proofofkeags): Implement
+	c := make(chan fn.Result[lntypes.ChannelParty], 1)
+
+	c <- fn.Errf[lntypes.ChannelParty]("InitStfu not implemented")
+
+	return c
+}
 
 func (f *mockChannelLink) FundingCustomBlob() fn.Option[tlv.Blob] {
 	return fn.None[tlv.Blob]()

peer/test_utils.go

@@ -24,6 +24,7 @@ import (
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lntest/channels"
 	"github.com/lightningnetwork/lnd/lntest/mock"
+	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -477,6 +478,14 @@ func (m *mockUpdateHandler) OnCommitOnce(
 
 	hook()
 }
+func (m *mockUpdateHandler) InitStfu() <-chan fn.Result[lntypes.ChannelParty] {
+	// TODO(proofofkeags): Implement
+	c := make(chan fn.Result[lntypes.ChannelParty], 1)
+
+	c <- fn.Errf[lntypes.ChannelParty]("InitStfu not yet implemented")
+
+	return c
+}
 
 func newMockConn(t *testing.T, expectedMessages int) *mockMessageConn {
 	return &mockMessageConn{