htlcswitch: thread clock from switch to mailbox

htlcswitch/mailbox.go

@@ -7,6 +7,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/lightningnetwork/lnd/clock"
 	"github.com/lightningnetwork/lnd/lnwire"
 )
 
@@ -79,6 +80,14 @@ type mailBoxConfig struct {
 	// be routed. A quit channel should be provided so that the call can
 	// properly exit during shutdown.
 	forwardPackets func(chan struct{}, ...*htlcPacket) chan error
+
+	// clock is a time source for the mailbox.
+	clock clock.Clock
+
+	// expiry is the interval after which Adds will be cancelled if they
+	// have not been yet been delivered. The computed deadline will expiry
+	// this long after the Adds are added via AddPacket.
+	expiry time.Duration
 }
 
 // memoryMailBox is an implementation of the MailBox struct backed by purely
@@ -586,6 +595,14 @@ type mailOrchConfig struct {
 	// fetchUpdate retreives the most recent channel update for the channel
 	// this mailbox belongs to.
 	fetchUpdate func(lnwire.ShortChannelID) (*lnwire.ChannelUpdate, error)
+
+	// clock is a time source for the generated mailboxes.
+	clock clock.Clock
+
+	// expiry is the interval after which Adds will be cancelled if they
+	// have not been yet been delivered. The computed deadline will expiry
+	// this long after the Adds are added to a mailbox via AddPacket.
+	expiry time.Duration
 }
 
 // newMailOrchestrator initializes a fresh mailOrchestrator.
@@ -642,6 +659,8 @@ func (mo *mailOrchestrator) exclusiveGetOrCreateMailBox(
 			shortChanID:    shortChanID,
 			fetchUpdate:    mo.cfg.fetchUpdate,
 			forwardPackets: mo.cfg.forwardPackets,
+			clock:          mo.cfg.clock,
+			expiry:         mo.cfg.expiry,
 		})
 		mailbox.Start()
 		mo.mailboxes[chanID] = mailbox

htlcswitch/mailbox_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/davecgh/go-spew/spew"
+	"github.com/lightningnetwork/lnd/clock"
 	"github.com/lightningnetwork/lnd/lnwire"
 )
 
@@ -19,7 +20,10 @@ func TestMailBoxCouriers(t *testing.T) {
 
 	// First, we'll create new instance of the current default mailbox
 	// type.
-	mailBox := newMemoryMailBox(&mailBoxConfig{})
+	mailBox := newMemoryMailBox(&mailBoxConfig{
+		clock:  clock.NewDefaultClock(),
+		expiry: time.Minute,
+	})
 	mailBox.Start()
 	defer mailBox.Stop()
 
@@ -172,14 +176,17 @@ func TestMailBoxResetAfterShutdown(t *testing.T) {
 
 type mailboxContext struct {
 	t        *testing.T
+	clock    *clock.TestClock
 	mailbox  MailBox
 	forwards chan *htlcPacket
 }
 
-func newMailboxContext(t *testing.T) *mailboxContext {
+func newMailboxContext(t *testing.T, startTime time.Time,
+	expiry time.Duration) *mailboxContext {
 
 	ctx := &mailboxContext{
 		t:        t,
+		clock:    clock.NewTestClock(startTime),
 		forwards: make(chan *htlcPacket, 1),
 	}
 	ctx.mailbox = newMemoryMailBox(&mailBoxConfig{
@@ -190,6 +197,8 @@ func newMailboxContext(t *testing.T) *mailboxContext {
 			}, nil
 		},
 		forwardPackets: ctx.forward,
+		clock:          ctx.clock,
+		expiry:         expiry,
 	})
 	ctx.mailbox.Start()
 
@@ -282,7 +291,7 @@ func (c *mailboxContext) checkFails(adds []*htlcPacket) {
 // TestMailBoxFailAdd asserts that FailAdd returns a response to the switch
 // under various interleavings with other operations on the mailbox.
 func TestMailBoxFailAdd(t *testing.T) {
-	ctx := newMailboxContext(t)
+	ctx := newMailboxContext(t, time.Now(), time.Minute)
 	defer ctx.mailbox.Stop()
 
 	failAdds := func(adds []*htlcPacket) {
@@ -316,7 +325,10 @@ func TestMailOrchestrator(t *testing.T) {
 	t.Parallel()
 
 	// First, we'll create a new instance of our orchestrator.
-	mo := newMailOrchestrator(&mailOrchConfig{})
+	mo := newMailOrchestrator(&mailOrchConfig{
+		clock:  clock.NewDefaultClock(),
+		expiry: time.Minute,
+	})
 	defer mo.Stop()
 
 	// We'll be delivering 10 htlc packets via the orchestrator.

htlcswitch/mock.go

@@ -177,6 +177,8 @@ func initSwitchWithDB(startingHeight uint32, db *channeldb.DB) (*Switch, error)
 		LogEventTicker: ticker.NewForce(DefaultLogInterval),
 		AckEventTicker: ticker.NewForce(DefaultAckInterval),
 		HtlcNotifier:   &mockHTLCNotifier{},
+		Clock:          clock.NewDefaultClock(),
+		HTLCExpiry:     time.Hour,
 	}
 
 	return New(cfg, startingHeight)

htlcswitch/switch.go

@@ -15,6 +15,7 @@ import (
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/channeldb/kvdb"
+	"github.com/lightningnetwork/lnd/clock"
 	"github.com/lightningnetwork/lnd/contractcourt"
 	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/lntypes"
@@ -36,6 +37,10 @@ const (
 	// DefaultAckInterval is the duration between attempts to ack any settle
 	// fails in a forwarding package.
 	DefaultAckInterval = 15 * time.Second
+
+	// DefaultHTLCExpiry is the duration after which Adds will be cancelled
+	// if they could not get added to an outgoing commitment.
+	DefaultHTLCExpiry = time.Minute
 )
 
 var (
@@ -174,6 +179,15 @@ type Config struct {
 	// RejectHTLC is a flag that instructs the htlcswitch to reject any
 	// HTLCs that are not from the source hop.
 	RejectHTLC bool
+
+	// Clock is a time source for the switch.
+	Clock clock.Clock
+
+	// HTLCExpiry is the interval after which Adds will be cancelled if they
+	// have not been yet been delivered to a link. The computed deadline
+	// will expiry this long after the Adds are added to a mailbox via
+	// AddPacket.
+	HTLCExpiry time.Duration
 }
 
 // Switch is the central messaging bus for all incoming/outgoing HTLCs.
@@ -301,6 +315,8 @@ func New(cfg Config, currentHeight uint32) (*Switch, error) {
 	s.mailOrchestrator = newMailOrchestrator(&mailOrchConfig{
 		fetchUpdate:    s.cfg.FetchLastChannelUpdate,
 		forwardPackets: s.ForwardPackets,
+		clock:          s.cfg.Clock,
+		expiry:         s.cfg.HTLCExpiry,
 	})
 
 	return s, nil

server.go

@@ -496,6 +496,8 @@ func newServer(listenAddrs []net.Addr, chanDB *channeldb.DB,
 		AckEventTicker:         ticker.New(htlcswitch.DefaultAckInterval),
 		AllowCircularRoute:     cfg.AllowCircularRoute,
 		RejectHTLC:             cfg.RejectHTLC,
+		Clock:                  clock.NewDefaultClock(),
+		HTLCExpiry:             htlcswitch.DefaultHTLCExpiry,
 	}, uint32(currentHeight))
 	if err != nil {
 		return nil, err