Merge pull request expanse-org#28 from ngtuna/masternode1

Masternode takes turn to create block

consensus/clique/clique.go

@@ -47,7 +47,8 @@ const (
 	inmemorySnapshots  = 128  // Number of recent vote snapshots to keep in memory
 	inmemorySignatures = 4096 // Number of recent block signatures to keep in memory
 
-	wiggleTime = 500 * time.Millisecond // Random delay (per signer) to allow concurrent signers
+	wiggleTime      = 500 * time.Millisecond // Random delay (per signer) to allow concurrent signers
+	genesisCoinBase = "0x0000000000000000000000000000000000000000"
 )
 
 // Clique proof-of-authority protocol constants.
@@ -374,6 +375,26 @@ func (c *Clique) GetSnapshot(chain consensus.ChainReader, header *types.Header)
 	return snap, nil
 }
 
+func position(list []common.Address, x common.Address) int {
+	for i, item := range list {
+		if item == x {
+			return i
+		}
+	}
+	return -1
+}
+
+func YourTurn(snap *Snapshot, header *types.Header, cur common.Address) (bool, error) {
+	pre, err := ecrecover(header, snap.sigcache)
+	if err != nil {
+		return false, err
+	}
+	preIndex := position(snap.signers(), pre)
+	curIndex := position(snap.signers(), cur)
+	log.Info("Debugging info", "number of masternodes", len(snap.signers()), "previous", pre, "position", preIndex, "current", cur, "position", curIndex)
+	return (preIndex+1)%len(snap.signers()) == curIndex || pre.String() == genesisCoinBase, nil
+}
+
 // snapshot retrieves the authorization snapshot at a given point in time.
 func (c *Clique) snapshot(chain consensus.ChainReader, number uint64, hash common.Hash, parents []*types.Header) (*Snapshot, error) {
 	// Search for a snapshot in memory or on disk for checkpoints

miner/worker.go

@@ -26,6 +26,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus"
+	"github.com/ethereum/go-ethereum/consensus/clique"
 	"github.com/ethereum/go-ethereum/consensus/misc"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/state"
@@ -397,6 +398,29 @@ func (self *worker) commitNewWork() {
 	tstart := time.Now()
 	parent := self.chain.CurrentBlock()
 
+	// Only try to commit new work if we are mining
+	if atomic.LoadInt32(&self.mining) == 1 {
+		// check if we are right after parent's coinbase in the list
+		// only go with Clique
+		if self.config.Clique != nil {
+			c := self.engine.(*clique.Clique)
+			snap, err := c.GetSnapshot(self.chain, parent.Header())
+			if err != nil {
+				log.Error("Failed when trying to commit new work", "err", err)
+				return
+			}
+			ok, err := clique.YourTurn(snap, parent.Header(), self.coinbase)
+			if err != nil {
+				log.Error("Failed when trying to commit new work", "err", err)
+				return
+			}
+			if !ok {
+				log.Info("Not our turn to commit block. Wait for next time")
+				return
+			}
+		}
+	}
+
 	tstamp := tstart.Unix()
 	if parent.Time().Cmp(new(big.Int).SetInt64(tstamp)) >= 0 {
 		tstamp = parent.Time().Int64() + 1