cmd, miner: get rid of external flag

cmd/geth/main.go

@@ -129,7 +129,6 @@ var (
 		utils.MinerLegacyExtraDataFlag,
 		utils.MinerRecommitIntervalFlag,
 		utils.MinerNoVerfiyFlag,
-		utils.MinerNoEmptyPrecommitFlag,
 		utils.NATFlag,
 		utils.NoDiscoverFlag,
 		utils.DiscoveryV5Flag,

cmd/geth/usage.go

@@ -210,7 +210,6 @@ var AppHelpFlagGroups = []flagGroup{
 			utils.MinerExtraDataFlag,
 			utils.MinerRecommitIntervalFlag,
 			utils.MinerNoVerfiyFlag,
-			utils.MinerNoEmptyPrecommitFlag,
 		},
 	},
 	{

cmd/utils/flags.go

@@ -483,10 +483,6 @@ var (
 		Name:  "miner.noverify",
 		Usage: "Disable remote sealing verification",
 	}
-	MinerNoEmptyPrecommitFlag = cli.BoolFlag{
-		Name:  "miner.noempty-precommit",
-		Usage: "Disable empty mining solution precommit",
-	}
 	// Account settings
 	UnlockedAccountFlag = cli.StringFlag{
 		Name:  "unlock",
@@ -1363,9 +1359,6 @@ func setMiner(ctx *cli.Context, cfg *miner.Config) {
 	if ctx.GlobalIsSet(MinerNoVerfiyFlag.Name) {
 		cfg.Noverify = ctx.Bool(MinerNoVerfiyFlag.Name)
 	}
-	if ctx.GlobalIsSet(MinerNoEmptyPrecommitFlag.Name) {
-		cfg.NoEmptyPrecommit = ctx.Bool(MinerNoEmptyPrecommitFlag.Name)
-	}
 }
 
 func setWhitelist(ctx *cli.Context, cfg *eth.Config) {

miner/miner.go

@@ -43,15 +43,14 @@ type Backend interface {
 
 // Config is the configuration parameters of mining.
 type Config struct {
-	Etherbase        common.Address `toml:",omitempty"` // Public address for block mining rewards (default = first account)
-	Notify           []string       `toml:",omitempty"` // HTTP URL list to be notified of new work packages(only useful in ethash).
-	ExtraData        hexutil.Bytes  `toml:",omitempty"` // Block extra data set by the miner
-	GasFloor         uint64         // Target gas floor for mined blocks.
-	GasCeil          uint64         // Target gas ceiling for mined blocks.
-	GasPrice         *big.Int       // Minimum gas price for mining a transaction
-	Recommit         time.Duration  // The time interval for miner to re-create mining work.
-	Noverify         bool           // Disable remote mining solution verification(only useful in ethash).
-	NoEmptyPrecommit bool           // Disable pre-commit empty mining solution
+	Etherbase common.Address `toml:",omitempty"` // Public address for block mining rewards (default = first account)
+	Notify    []string       `toml:",omitempty"` // HTTP URL list to be notified of new work packages(only useful in ethash).
+	ExtraData hexutil.Bytes  `toml:",omitempty"` // Block extra data set by the miner
+	GasFloor  uint64         // Target gas floor for mined blocks.
+	GasCeil   uint64         // Target gas ceiling for mined blocks.
+	GasPrice  *big.Int       // Minimum gas price for mining a transaction
+	Recommit  time.Duration  // The time interval for miner to re-create mining work.
+	Noverify  bool           // Disable remote mining solution verification(only useful in ethash).
 }
 
 // Miner creates blocks and searches for proof-of-work values.
@@ -184,6 +183,23 @@ func (miner *Miner) SetEtherbase(addr common.Address) {
 	miner.worker.setEtherbase(addr)
 }
 
+// EnablePreseal turns on the preseal mining feature. It's enabled by default.
+// Note this function shouldn't be exposed to API, it's unnecessary for users
+// (miners) to actually know the underlying detail. It's only for outside project
+// which uses this library.
+func (miner *Miner) EnablePreseal() {
+	miner.worker.enablePreseal()
+}
+
+// DisablePreseal turns off the preseal mining feature. It's necessary for some
+// fake consensus engine which can seal blocks instantaneously.
+// Note this function shouldn't be exposed to API, it's unnecessary for users
+// (miners) to actually know the underlying detail. It's only for outside project
+// which uses this library.
+func (miner *Miner) DisablePreseal() {
+	miner.worker.disablePreseal()
+}
+
 // SubscribePendingLogs starts delivering logs from pending transactions
 // to the given channel.
 func (self *Miner) SubscribePendingLogs(ch chan<- []*types.Log) event.Subscription {

miner/worker.go

@@ -169,6 +169,13 @@ type worker struct {
 	running int32 // The indicator whether the consensus engine is running or not.
 	newTxs  int32 // New arrival transaction count since last sealing work submitting.
 
+	// noempty is the flag used to control whether the feature of pre-seal
+	// empty block is enabled. The default value is false.
+	// But in some special scenario the consensus engine will seal blocks
+	// instantaneously, in this case this feature will add all empty blocks
+	// into canonical chain non-stop and no real transaction will be included.
+	noempty bool
+
 	// External functions
 	isLocalBlock func(block *types.Block) bool // Function used to determine whether the specified block is mined by local miner.
 
@@ -247,6 +254,16 @@ func (w *worker) setRecommitInterval(interval time.Duration) {
 	w.resubmitIntervalCh <- interval
 }
 
+// disablePreseal disables pre-sealing mining feature
+func (w *worker) disablePreseal() {
+	w.noempty = true
+}
+
+// enablePreseal enables pre-sealing mining feature
+func (w *worker) enablePreseal() {
+	w.noempty = false
+}
+
 // pending returns the pending state and corresponding block.
 func (w *worker) pending() (*types.Block, *state.StateDB) {
 	// return a snapshot to avoid contention on currentMu mutex
@@ -305,10 +322,6 @@ func (w *worker) newWorkLoop(recommit time.Duration) {
 		if interrupt != nil {
 			atomic.StoreInt32(interrupt, s)
 		}
-		// Disable empty mining solution precommit if required.
-		if !noempty && w.config.NoEmptyPrecommit {
-			noempty = true
-		}
 		interrupt = new(int32)
 		w.newWorkCh <- &newWorkReq{interrupt: interrupt, noempty: noempty, timestamp: timestamp}
 		timer.Reset(recommit)
@@ -484,8 +497,9 @@ func (w *worker) mainLoop() {
 					w.updateSnapshot()
 				}
 			} else {
-				// If clique is running in dev mode(period is 0), disable
-				// advance sealing here.
+				// Speical case, if the consensus engine is 0 period clique(dev mode),
+				// submit mining work here since all empty submission will be rejected
+				// by clique. Of course the advance sealing(empty submission) is disabled.
 				if w.chainConfig.Clique != nil && w.chainConfig.Clique.Period == 0 {
 					w.commitNewWork(nil, true, time.Now().Unix())
 				}
@@ -914,9 +928,9 @@ func (w *worker) commitNewWork(interrupt *int32, noempty bool, timestamp int64)
 	commitUncles(w.localUncles)
 	commitUncles(w.remoteUncles)
 
-	if !noempty {
-		// Create an empty block based on temporary copied state for sealing in advance without waiting block
-		// execution finished.
+	// Create an empty block based on temporary copied state for
+	// sealing in advance without waiting block execution finished.
+	if !noempty && !w.noempty {
 		w.commit(uncles, nil, false, tstart)
 	}
 
@@ -929,7 +943,7 @@ func (w *worker) commitNewWork(interrupt *int32, noempty bool, timestamp int64)
 	// Short circuit if there is no available pending transactions.
 	// But if we disable empty precommit already, ignore it. Since
 	// empty block is necessary to keep the liveness of the network.
-	if len(pending) == 0 && !w.config.NoEmptyPrecommit {
+	if len(pending) == 0 && !w.noempty {
 		w.updateSnapshot()
 		return
 	}