feat: implement relaxed period in clique

consensus/clique/clique.go

@@ -328,7 +328,7 @@ func (c *Clique) verifyCascadingFields(chain consensus.ChainHeaderReader, header
 	if parent == nil || parent.Number.Uint64() != number-1 || parent.Hash() != header.ParentHash {
 		return consensus.ErrUnknownAncestor
 	}
-	if parent.Time+c.config.Period > header.Time {
+	if header.Time < parent.Time {
 		return errInvalidTimestamp
 	}
 	// Verify that the gasUsed is <= gasLimit
@@ -555,7 +555,9 @@ func (c *Clique) Prepare(chain consensus.ChainHeaderReader, header *types.Header
 		return consensus.ErrUnknownAncestor
 	}
 	header.Time = parent.Time + c.config.Period
-	if header.Time < uint64(time.Now().Unix()) {
+	// If RelaxedPeriod is enabled, always set the header timestamp to now (ie the time we start building it) as
+	// we don't know when it will be sealed
+	if c.config.RelaxedPeriod || header.Time < uint64(time.Now().Unix()) {
 		header.Time = uint64(time.Now().Unix())
 	}
 	return nil

miner/scroll_worker.go

@@ -708,7 +708,14 @@ func (w *worker) startNewPipeline(timestamp int64) {
 
 	w.currentPipelineStart = time.Now()
 	w.currentPipeline = pipeline.NewPipeline(w.chain, w.chain.GetVMConfig(), parentState, header, nextL1MsgIndex, w.getCCC()).WithBeforeTxHook(w.beforeTxHook)
-	if err := w.currentPipeline.Start(time.Unix(int64(header.Time), 0)); err != nil {
+
+	deadline := time.Unix(int64(header.Time), 0)
+	if w.chainConfig.Clique != nil && w.chainConfig.Clique.RelaxedPeriod {
+		// clique with relaxed period uses time.Now() as the header.Time, calculate the deadline
+		deadline = time.Unix(int64(header.Time+w.chainConfig.Clique.Period), 0)
+	}
+
+	if err := w.currentPipeline.Start(deadline); err != nil {
 		log.Error("failed to start pipeline", "err", err)
 		return
 	}

params/config.go

@@ -602,8 +602,9 @@ func (c *EthashConfig) String() string {
 
 // CliqueConfig is the consensus engine configs for proof-of-authority based sealing.
 type CliqueConfig struct {
-	Period uint64 `json:"period"` // Number of seconds between blocks to enforce
-	Epoch  uint64 `json:"epoch"`  // Epoch length to reset votes and checkpoint
+	Period        uint64 `json:"period"`         // Number of seconds between blocks to enforce
+	Epoch         uint64 `json:"epoch"`          // Epoch length to reset votes and checkpoint
+	RelaxedPeriod bool   `json:"relaxed_period"` // Relaxes the period to be just an upper bound
 }
 
 // String implements the stringer interface, returning the consensus engine details.

params/version.go

@@ -24,7 +24,7 @@ import (
 const (
 	VersionMajor = 5         // Major version component of the current release
 	VersionMinor = 3         // Minor version component of the current release
-	VersionPatch = 18        // Patch version component of the current release
+	VersionPatch = 19        // Patch version component of the current release
 	VersionMeta  = "mainnet" // Version metadata to append to the version string
 )