core: fix stuffs (#448)

* Add log

* core: delay first dkg

* Fix test

* core: only runDKG in prepare at round 0

3 files changed, 26 insertions, 16 deletions

diff --git a/core/blockchain.go b/core/blockchain.go
index bfa8552..d1aa644 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -550,9 +550,13 @@ func (bc *blockChain) prepareBlock(position types.Position,
 		}
 		b.ParentHash = tip.Hash
 		if !empty {
+			bc.logger.Debug("Calling Application.PreparePayload",
+				"position", b.Position)
 			if b.Payload, err = bc.app.PreparePayload(b.Position); err != nil {
 				return
 			}
+			bc.logger.Debug("Calling Application.PrepareWitness",
+				"height", tip.Witness.Height)
 			if b.Witness, err = bc.app.PrepareWitness(
 				tip.Witness.Height); err != nil {
 				return
diff --git a/core/consensus.go b/core/consensus.go
index ebbcbd1..f4c0a37 100644
--- a/core/consensus.go
+++ b/core/consensus.go
@@ -590,23 +590,28 @@ func (con *Consensus) prepare(initBlock *types.Block) (err error) {
 	if err = con.bcModule.appendConfig(initRound+1, initPlusOneCfg); err != nil {
 		return
 	}
-	// Register events.
-	dkgSet, err := con.nodeSetCache.GetDKGSet(initRound)
-	if err != nil {
-		return
-	}
-	if _, exist := dkgSet[con.ID]; exist {
-		con.logger.Info("Selected as DKG set", "round", initRound)
-		go func() {
-			// Sleep until dMoment come.
-			time.Sleep(con.dMoment.Sub(time.Now().UTC()))
-			con.cfgModule.registerDKG(initRound, getDKGThreshold(initConfig))
-			con.event.RegisterTime(con.dMoment.Add(initConfig.RoundInterval/4),
-				func(time.Time) {
-					con.runDKG(initRound, initConfig)
-				})
-		}()
+	if initRound == 0 {
+		dkgSet, err := con.nodeSetCache.GetDKGSet(initRound)
+		if err != nil {
+			return err
+		}
+		if _, exist := dkgSet[con.ID]; exist {
+			con.logger.Info("Selected as DKG set", "round", initRound)
+			go func() {
+				// Sleep until dMoment come.
+				time.Sleep(con.dMoment.Sub(time.Now().UTC()))
+				// Network is not stable upon starting. Wait some time to ensure first
+				// DKG would success. Three is a magic number.
+				time.Sleep(initConfig.MinBlockInterval * 3)
+				con.cfgModule.registerDKG(initRound, getDKGThreshold(initConfig))
+				con.event.RegisterTime(con.dMoment.Add(initConfig.RoundInterval/4),
+					func(time.Time) {
+						con.runDKG(initRound, initConfig)
+					})
+			}()
+		}
 	}
+	// Register events.
 	con.initialRound(con.dMoment, initRound, initConfig)
 	return
 }
diff --git a/core/consensus_test.go b/core/consensus_test.go
index 67070d2..fe28320 100644
--- a/core/consensus_test.go
+++ b/core/consensus_test.go
@@ -237,6 +237,7 @@ func (s *ConsensusTestSuite) TestDKGCRS() {
 		nID := types.NewNodeID(key.PublicKey())
 		cons[nID] = con
 	}
+	time.Sleep(gov.Configuration(0).MinBlockInterval * 4)
 	for _, con := range cons {
 		go con.runDKG(0, gov.Configuration(0))
 	}