core/vote: wait some blocks beforing voting since mining begin

core/vote/vote_manager.go

@@ -15,6 +15,8 @@ import (
 	"github.com/ethereum/go-ethereum/metrics"
 )
 
+const blocksNumberSinceMining = 5 // the number of blocks need to wait before voting, counting from the validator begin to mine
+
 var votesManagerCounter = metrics.NewRegisteredCounter("votesManager/local", nil)
 
 // Backend wraps all methods required for voting.
@@ -95,6 +97,7 @@ func (voteManager *VoteManager) loop() {
 	dlEventCh := events.Chan()
 
 	startVote := true
+	blockCountSinceMining := 0
 	var once sync.Once
 	for {
 		select {
@@ -120,9 +123,15 @@ func (voteManager *VoteManager) loop() {
 				continue
 			}
 			if !voteManager.eth.IsMining() {
+				blockCountSinceMining = 0
 				log.Debug("skip voting because mining is disabled, continue")
 				continue
 			}
+			blockCountSinceMining++
+			if blockCountSinceMining <= blocksNumberSinceMining {
+				log.Debug("skip voting", "blockCountSinceMining", blockCountSinceMining, "blocksNumberSinceMining", blocksNumberSinceMining)
+				continue
+			}
 
 			if cHead.Block == nil {
 				log.Debug("cHead.Block is nil, continue")

core/vote/vote_pool_test.go

@@ -190,7 +190,7 @@ func testVotePool(t *testing.T, isValidRules bool) {
 	if _, err := chain.InsertChain(bs); err != nil {
 		panic(err)
 	}
-	for i := 0; i < 10; i++ {
+	for i := 0; i < 10+blocksNumberSinceMining; i++ {
 		bs, _ = core.GenerateChain(params.TestChainConfig, bs[len(bs)-1], ethash.NewFaker(), db, 1, nil)
 		if _, err := chain.InsertChain(bs); err != nil {
 			panic(err)