feat(worker): allow empty blocks (#1153)

cmd/geth/main.go

@@ -133,6 +133,7 @@ var (
 		utils.MinerNoVerifyFlag,
 		utils.MinerStoreSkippedTxTracesFlag,
 		utils.MinerMaxAccountsNumFlag,
+		utils.MinerAllowEmptyFlag,
 		utils.NATFlag,
 		utils.NoDiscoverFlag,
 		utils.DiscoveryV5Flag,

cmd/geth/usage.go

@@ -197,6 +197,7 @@ var AppHelpFlagGroups = []flags.FlagGroup{
 			utils.MinerNoVerifyFlag,
 			utils.MinerStoreSkippedTxTracesFlag,
 			utils.MinerMaxAccountsNumFlag,
+			utils.MinerAllowEmptyFlag,
 		},
 	},
 	{

cmd/utils/flags.go

@@ -515,6 +515,10 @@ var (
 		Usage: "Maximum number of accounts that miner will fetch the pending transactions of when building a new block",
 		Value: math.MaxInt,
 	}
+	MinerAllowEmptyFlag = cli.BoolFlag{
+		Name:  "miner.allowempty",
+		Usage: "Allow sealing empty blocks",
+	}
 	// Account settings
 	UnlockedAccountFlag = cli.StringFlag{
 		Name:  "unlock",
@@ -1620,6 +1624,9 @@ func setMiner(ctx *cli.Context, cfg *miner.Config) {
 	if ctx.GlobalIsSet(MinerMaxAccountsNumFlag.Name) {
 		cfg.MaxAccountsNum = ctx.GlobalInt(MinerMaxAccountsNumFlag.Name)
 	}
+	if ctx.GlobalIsSet(MinerAllowEmptyFlag.Name) {
+		cfg.AllowEmpty = ctx.GlobalBool(MinerAllowEmptyFlag.Name)
+	}
 	if ctx.GlobalIsSet(LegacyMinerGasTargetFlag.Name) {
 		log.Warn("The generic --miner.gastarget flag is deprecated and will be removed in the future!")
 	}

miner/miner.go

@@ -60,6 +60,7 @@ type Config struct {
 	StoreSkippedTxTraces bool // Whether store the wrapped traces when storing a skipped tx
 	MaxAccountsNum       int  // Maximum number of accounts that miner will fetch the pending transactions of when building a new block
 	CCCMaxWorkers        int  // Maximum number of workers to use for async CCC tasks
+	AllowEmpty           bool // If true, then we allow sealing empty blocks
 
 	SigningDisabled bool // Whether to disable signing blocks with consensus enginek
 }

miner/scroll_worker.go

@@ -400,6 +400,9 @@ func (w *worker) mainLoop() {
 			w.current.deadlineReached = true
 			if len(w.current.txs) > 0 {
 				_, err = w.commit()
+			} else if w.config.AllowEmpty {
+				log.Warn("Committing empty block", "number", w.current.header.Number)
+				_, err = w.commit()
 			}
 		case ev := <-w.txsCh:
 			idleTimer.UpdateSince(idleStart)

params/version.go

@@ -24,7 +24,7 @@ import (
 const (
 	VersionMajor = 5         // Major version component of the current release
 	VersionMinor = 8         // Minor version component of the current release
-	VersionPatch = 28        // Patch version component of the current release
+	VersionPatch = 29        // Patch version component of the current release
 	VersionMeta  = "mainnet" // Version metadata to append to the version string
 )