Merge pull request #2788 from OffchainLabs/express-lane-timeboost-ear…

…ly-submission-grace

Add early timeboost submission grace period

cmd/nitro/nitro.go

@@ -660,7 +660,9 @@ func mainImpl() int {
 			execNode.Backend.APIBackend(),
 			execNode.FilterSystem,
 			common.HexToAddress(execNodeConfig.Sequencer.Timeboost.AuctionContractAddress),
-			common.HexToAddress(execNodeConfig.Sequencer.Timeboost.AuctioneerAddress))
+			common.HexToAddress(execNodeConfig.Sequencer.Timeboost.AuctioneerAddress),
+			execNodeConfig.Sequencer.Timeboost.EarlySubmissionGrace,
+		)
 	}
 
 	err = nil

execution/gethexec/express_lane_service.go

@@ -52,6 +52,7 @@ type expressLaneService struct {
 	initialTimestamp         time.Time
 	roundDuration            time.Duration
 	auctionClosing           time.Duration
+	earlySubmissionGrace     time.Duration
 	chainConfig              *params.ChainConfig
 	logs                     chan []*types.Log
 	auctionContract          *express_lane_auctiongen.ExpressLaneAuction
@@ -128,6 +129,7 @@ func newExpressLaneService(
 	filterSystem *filters.FilterSystem,
 	auctionContractAddr common.Address,
 	bc *core.BlockChain,
+	earlySubmissionGrace time.Duration,
 ) (*expressLaneService, error) {
 	chainConfig := bc.Config()
 
@@ -167,6 +169,7 @@ pending:
 		chainConfig:              chainConfig,
 		initialTimestamp:         initialTimestamp,
 		auctionClosing:           auctionClosingDuration,
+		earlySubmissionGrace:     earlySubmissionGrace,
 		roundControl:             lru.NewCache[uint64, *expressLaneControl](8), // Keep 8 rounds cached.
 		auctionContractAddr:      auctionContractAddr,
 		roundDuration:            roundDuration,
@@ -397,9 +400,23 @@ func (es *expressLaneService) validateExpressLaneTx(msg *timeboost.ExpressLaneSu
 	if msg.AuctionContractAddress != es.auctionContractAddr {
 		return errors.Wrapf(timeboost.ErrWrongAuctionContract, "msg auction contract address %s does not match sequencer auction contract address %s", msg.AuctionContractAddress, es.auctionContractAddr)
 	}
-	currentRound := timeboost.CurrentRound(es.initialTimestamp, es.roundDuration)
-	if msg.Round != currentRound {
-		return errors.Wrapf(timeboost.ErrBadRoundNumber, "express lane tx round %d does not match current round %d", msg.Round, currentRound)
+
+	for {
+		currentRound := timeboost.CurrentRound(es.initialTimestamp, es.roundDuration)
+		if msg.Round == currentRound {
+			break
+		}
+
+		currentTime := time.Now()
+		if msg.Round == currentRound+1 &&
+			timeboost.TimeTilNextRoundAfterTimestamp(es.initialTimestamp, currentTime, es.roundDuration) <= es.earlySubmissionGrace {
+			// If it becomes the next round in between checking the currentRound
+			// above, and here, then this will be a negative duration which is
+			// treated as time.Sleep(0), which is fine.
+			time.Sleep(timeboost.TimeTilNextRoundAfterTimestamp(es.initialTimestamp, currentTime, es.roundDuration))
+		} else {
+			return errors.Wrapf(timeboost.ErrBadRoundNumber, "express lane tx round %d does not match current round %d", msg.Round, currentRound)
+		}
 	}
 	if !es.currentRoundHasController() {
 		return timeboost.ErrNoOnchainController

execution/gethexec/express_lane_service_test.go

@@ -24,14 +24,19 @@ import (
 	"github.com/offchainlabs/nitro/timeboost"
 )
 
-var testPriv *ecdsa.PrivateKey
+var testPriv, testPriv2 *ecdsa.PrivateKey
 
 func init() {
 	privKey, err := crypto.HexToECDSA("93be75cc4df7acbb636b6abe6de2c0446235ac1dc7da9f290a70d83f088b486d")
 	if err != nil {
 		panic(err)
 	}
 	testPriv = privKey
+	privKey2, err := crypto.HexToECDSA("93be75cc4df7acbb636b6abe6de2c0446235ac1dc7da9f290a70d83f088b486e")
+	if err != nil {
+		panic(err)
+	}
+	testPriv2 = privKey2
 }
 
 func Test_expressLaneService_validateExpressLaneTx(t *testing.T) {
@@ -195,7 +200,7 @@ func Test_expressLaneService_validateExpressLaneTx(t *testing.T) {
 			control: expressLaneControl{
 				controller: common.Address{'b'},
 			},
-			sub:         buildValidSubmission(t, common.HexToAddress("0x2Aef36410182881a4b13664a1E079762D7F716e6"), testPriv),
+			sub:         buildValidSubmission(t, common.HexToAddress("0x2Aef36410182881a4b13664a1E079762D7F716e6"), testPriv, 0),
 			expectedErr: timeboost.ErrNotExpressLaneController,
 		},
 		{
@@ -212,7 +217,7 @@ func Test_expressLaneService_validateExpressLaneTx(t *testing.T) {
 			control: expressLaneControl{
 				controller: crypto.PubkeyToAddress(testPriv.PublicKey),
 			},
-			sub:   buildValidSubmission(t, common.HexToAddress("0x2Aef36410182881a4b13664a1E079762D7F716e6"), testPriv),
+			sub:   buildValidSubmission(t, common.HexToAddress("0x2Aef36410182881a4b13664a1E079762D7F716e6"), testPriv, 0),
 			valid: true,
 		},
 	}
@@ -233,6 +238,46 @@ func Test_expressLaneService_validateExpressLaneTx(t *testing.T) {
 	}
 }
 
+func Test_expressLaneService_validateExpressLaneTx_gracePeriod(t *testing.T) {
+	auctionContractAddr := common.HexToAddress("0x2Aef36410182881a4b13664a1E079762D7F716e6")
+	es := &expressLaneService{
+		auctionContractAddr:  auctionContractAddr,
+		initialTimestamp:     time.Now(),
+		roundDuration:        time.Second * 10,
+		auctionClosing:       time.Second * 5,
+		earlySubmissionGrace: time.Second * 2,
+		chainConfig: &params.ChainConfig{
+			ChainID: big.NewInt(1),
+		},
+		roundControl: lru.NewCache[uint64, *expressLaneControl](8),
+	}
+	es.roundControl.Add(0, &expressLaneControl{
+		controller: crypto.PubkeyToAddress(testPriv.PublicKey),
+	})
+	es.roundControl.Add(1, &expressLaneControl{
+		controller: crypto.PubkeyToAddress(testPriv2.PublicKey),
+	})
+
+	sub1 := buildValidSubmission(t, auctionContractAddr, testPriv, 0)
+	err := es.validateExpressLaneTx(sub1)
+	require.NoError(t, err)
+
+	// Send req for next round
+	sub2 := buildValidSubmission(t, auctionContractAddr, testPriv2, 1)
+	err = es.validateExpressLaneTx(sub2)
+	require.ErrorIs(t, err, timeboost.ErrBadRoundNumber)
+
+	// Sleep til 2 seconds before grace
+	time.Sleep(time.Second * 6)
+	err = es.validateExpressLaneTx(sub2)
+	require.ErrorIs(t, err, timeboost.ErrBadRoundNumber)
+
+	// Send req for next round within grace period
+	time.Sleep(time.Second * 2)
+	err = es.validateExpressLaneTx(sub2)
+	require.NoError(t, err)
+}
+
 type stubPublisher struct {
 	els              *expressLaneService
 	publishedTxOrder []uint64
@@ -463,7 +508,7 @@ func Benchmark_expressLaneService_validateExpressLaneTx(b *testing.B) {
 		sequence:   1,
 		controller: addr,
 	})
-	sub := buildValidSubmission(b, common.HexToAddress("0x2Aef36410182881a4b13664a1E079762D7F716e6"), testPriv)
+	sub := buildValidSubmission(b, common.HexToAddress("0x2Aef36410182881a4b13664a1E079762D7F716e6"), testPriv, 0)
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
 		err := es.validateExpressLaneTx(sub)
@@ -512,13 +557,14 @@ func buildValidSubmission(
 	t testing.TB,
 	auctionContractAddr common.Address,
 	privKey *ecdsa.PrivateKey,
+	round uint64,
 ) *timeboost.ExpressLaneSubmission {
 	b := &timeboost.ExpressLaneSubmission{
 		ChainId:                big.NewInt(1),
 		AuctionContractAddress: auctionContractAddr,
 		Transaction:            types.NewTransaction(0, common.Address{}, big.NewInt(0), 0, big.NewInt(0), nil),
 		Signature:              make([]byte, 65),
-		Round:                  0,
+		Round:                  round,
 	}
 	data, err := b.ToMessageBytes()
 	require.NoError(t, err)

execution/gethexec/sequencer.go

@@ -89,13 +89,17 @@ type TimeboostConfig struct {
 	AuctionContractAddress string        `koanf:"auction-contract-address"`
 	AuctioneerAddress      string        `koanf:"auctioneer-address"`
 	ExpressLaneAdvantage   time.Duration `koanf:"express-lane-advantage"`
+	SequencerHTTPEndpoint  string        `koanf:"sequencer-http-endpoint"`
+	EarlySubmissionGrace   time.Duration `koanf:"early-submission-grace"`
 }
 
 var DefaultTimeboostConfig = TimeboostConfig{
 	Enable:                 false,
 	AuctionContractAddress: "",
 	AuctioneerAddress:      "",
 	ExpressLaneAdvantage:   time.Millisecond * 200,
+	SequencerHTTPEndpoint:  "http://localhost:8547",
+	EarlySubmissionGrace:   time.Second * 2,
 }
 
 func (c *SequencerConfig) Validate() error {
@@ -188,6 +192,8 @@ func TimeboostAddOptions(prefix string, f *flag.FlagSet) {
 	f.String(prefix+".auction-contract-address", DefaultTimeboostConfig.AuctionContractAddress, "Address of the proxy pointing to the ExpressLaneAuction contract")
 	f.String(prefix+".auctioneer-address", DefaultTimeboostConfig.AuctioneerAddress, "Address of the Timeboost Autonomous Auctioneer")
 	f.Duration(prefix+".express-lane-advantage", DefaultTimeboostConfig.ExpressLaneAdvantage, "specify the express lane advantage")
+	f.String(prefix+".sequencer-http-endpoint", DefaultTimeboostConfig.SequencerHTTPEndpoint, "this sequencer's http endpoint")
+	f.Duration(prefix+".early-submission-grace", DefaultTimeboostConfig.EarlySubmissionGrace, "period of time before the next round where submissions for the next round will be queued")
 }
 
 type txQueueItem struct {
@@ -1274,7 +1280,14 @@ func (s *Sequencer) Start(ctxIn context.Context) error {
 	return nil
 }
 
-func (s *Sequencer) StartExpressLane(ctx context.Context, apiBackend *arbitrum.APIBackend, filterSystem *filters.FilterSystem, auctionContractAddr common.Address, auctioneerAddr common.Address) {
+func (s *Sequencer) StartExpressLane(
+	ctx context.Context,
+	apiBackend *arbitrum.APIBackend,
+	filterSystem *filters.FilterSystem,
+	auctionContractAddr common.Address,
+	auctioneerAddr common.Address,
+	earlySubmissionGrace time.Duration,
+) {
 	if !s.config().Timeboost.Enable {
 		log.Crit("Timeboost is not enabled, but StartExpressLane was called")
 	}
@@ -1285,6 +1298,7 @@ func (s *Sequencer) StartExpressLane(ctx context.Context, apiBackend *arbitrum.A
 		filterSystem,
 		auctionContractAddr,
 		s.execEngine.bc,
+		earlySubmissionGrace,
 	)
 	if err != nil {
 		log.Crit("Failed to create express lane service", "err", err, "auctionContractAddr", auctionContractAddr)

system_tests/timeboost_test.go

@@ -415,7 +415,7 @@ func setupExpressLaneAuction(
 	// This is hacky- we are manually starting the ExpressLaneService here instead of letting it be started
 	// by the sequencer. This is due to needing to deploy the auction contract first.
 	builderSeq.execConfig.Sequencer.Timeboost.Enable = true
-	builderSeq.L2.ExecNode.Sequencer.StartExpressLane(ctx, builderSeq.L2.ExecNode.Backend.APIBackend(), builderSeq.L2.ExecNode.FilterSystem, proxyAddr, seqInfo.GetAddress("AuctionContract"))
+	builderSeq.L2.ExecNode.Sequencer.StartExpressLane(ctx, builderSeq.L2.ExecNode.Backend.APIBackend(), builderSeq.L2.ExecNode.FilterSystem, proxyAddr, seqInfo.GetAddress("AuctionContract"), gethexec.DefaultTimeboostConfig.EarlySubmissionGrace)
 	t.Log("Started express lane service in sequencer")
 
 	// Set up an autonomous auction contract service that runs in the background in this test.

timeboost/ticker.go

@@ -49,10 +49,15 @@ func (t *auctionCloseTicker) start() {
 
 // CurrentRound returns the current round number.
 func CurrentRound(initialRoundTimestamp time.Time, roundDuration time.Duration) uint64 {
+	return RoundAtTimestamp(initialRoundTimestamp, time.Now(), roundDuration)
+}
+
+// CurrentRound returns the round number as of some timestamp.
+func RoundAtTimestamp(initialRoundTimestamp time.Time, currentTime time.Time, roundDuration time.Duration) uint64 {
 	if roundDuration == 0 {
 		return 0
 	}
-	return arbmath.SaturatingUCast[uint64](time.Since(initialRoundTimestamp) / roundDuration)
+	return arbmath.SaturatingUCast[uint64](currentTime.Sub(initialRoundTimestamp) / roundDuration)
 }
 
 func isAuctionRoundClosed(
@@ -81,7 +86,14 @@ func timeIntoRound(
 func TimeTilNextRound(
 	initialTimestamp time.Time,
 	roundDuration time.Duration) time.Duration {
-	currentRoundNum := CurrentRound(initialTimestamp, roundDuration)
+	return TimeTilNextRoundAfterTimestamp(initialTimestamp, time.Now(), roundDuration)
+}
+
+func TimeTilNextRoundAfterTimestamp(
+	initialTimestamp time.Time,
+	currentTime time.Time,
+	roundDuration time.Duration) time.Duration {
+	currentRoundNum := RoundAtTimestamp(initialTimestamp, currentTime, roundDuration)
 	nextRoundStart := initialTimestamp.Add(roundDuration * arbmath.SaturatingCast[time.Duration](currentRoundNum+1))
 	return time.Until(nextRoundStart)
 }