// Copyright 2018 The dexon-consensus Authors
// This file is part of the dexon-consensus library.
//
// The dexon-consensus library is free software: you can redistribute it
// and/or modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// The dexon-consensus library is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
// General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the dexon-consensus library. If not, see
// <http://www.gnu.org/licenses/>.
package core
import (
"context"
"encoding/hex"
"fmt"
"sync"
"sync/atomic"
"time"
"github.com/dexon-foundation/dexon-consensus/common"
"github.com/dexon-foundation/dexon-consensus/core/crypto"
"github.com/dexon-foundation/dexon-consensus/core/db"
"github.com/dexon-foundation/dexon-consensus/core/types"
typesDKG "github.com/dexon-foundation/dexon-consensus/core/types/dkg"
"github.com/dexon-foundation/dexon-consensus/core/utils"
)
// Errors for consensus core.
var (
ErrProposerNotInNodeSet = fmt.Errorf(
"proposer is not in node set")
ErrIncorrectHash = fmt.Errorf(
"hash of block is incorrect")
ErrIncorrectSignature = fmt.Errorf(
"signature of block is incorrect")
ErrGenesisBlockNotEmpty = fmt.Errorf(
"genesis block should be empty")
ErrUnknownBlockProposed = fmt.Errorf(
"unknown block is proposed")
ErrIncorrectAgreementResultPosition = fmt.Errorf(
"incorrect agreement result position")
ErrNotEnoughVotes = fmt.Errorf(
"not enought votes")
ErrCRSNotReady = fmt.Errorf(
"CRS not ready")
ErrConfigurationNotReady = fmt.Errorf(
"Configuration not ready")
)
// consensusBAReceiver implements agreementReceiver.
type consensusBAReceiver struct {
// TODO(mission): consensus would be replaced by blockChain and network.
consensus *Consensus
agreementModule *agreement
changeNotaryTime time.Time
roundValue *atomic.Value
isNotary bool
restartNotary chan types.Position
}
func (recv *consensusBAReceiver) round() uint64 {
return recv.roundValue.Load().(uint64)
}
func (recv *consensusBAReceiver) ProposeVote(vote *types.Vote) {
if !recv.isNotary {
return
}
if err := recv.agreementModule.prepareVote(vote); err != nil {
recv.consensus.logger.Error("Failed to prepare vote", "error", err)
return
}
go func() {
if err := recv.agreementModule.processVote(vote); err != nil {
recv.consensus.logger.Error("Failed to process self vote",
"error", err,
"vote", vote)
return
}
recv.consensus.logger.Debug("Calling Network.BroadcastVote",
"vote", vote)
recv.consensus.network.BroadcastVote(vote)
}()
}
func (recv *consensusBAReceiver) ProposeBlock() common.Hash {
if !recv.isNotary {
return common.Hash{}
}
block, err := recv.consensus.proposeBlock(recv.agreementModule.agreementID())
if err != nil || block == nil {
recv.consensus.logger.Error("unable to propose block", "error", err)
return types.NullBlockHash
}
go func() {
if err := recv.consensus.preProcessBlock(block); err != nil {
recv.consensus.logger.Error("Failed to pre-process block", "error", err)
return
}
recv.consensus.logger.Debug("Calling Network.BroadcastBlock",
"block", block)
recv.consensus.network.BroadcastBlock(block)
}()
return block.Hash
}
func (recv *consensusBAReceiver) ConfirmBlock(
hash common.Hash, votes map[types.NodeID]*types.Vote) {
var (
block *types.Block
aID = recv.agreementModule.agreementID()
)
isEmptyBlockConfirmed := hash == common.Hash{}
if isEmptyBlockConfirmed {
recv.consensus.logger.Info("Empty block is confirmed", "position", aID)
var err error
block, err = recv.consensus.bcModule.addEmptyBlock(aID)
if err != nil {
recv.consensus.logger.Error("Add position for empty failed",
"error", err)
return
}
if block == nil {
panic(fmt.Errorf("empty block should be proposed directly: %s", aID))
}
} else {
var exist bool
block, exist = recv.agreementModule.findBlockNoLock(hash)
if !exist {
recv.consensus.logger.Error("Unknown block confirmed",
"hash", hash.String()[:6])
ch := make(chan *types.Block)
func() {
recv.consensus.lock.Lock()
defer recv.consensus.lock.Unlock()
recv.consensus.baConfirmedBlock[hash] = ch
}()
go func() {
hashes := common.Hashes{hash}
PullBlockLoop:
for {
recv.consensus.logger.Debug("Calling Network.PullBlock for BA block",
"hash", hash)
recv.consensus.network.PullBlocks(hashes)
select {
case block = <-ch:
break PullBlockLoop
case <-time.After(1 * time.Second):
}
}
recv.consensus.logger.Info("Receive unknown block",
"hash", hash.String()[:6],
"position", block.Position)
recv.agreementModule.addCandidateBlock(block)
recv.agreementModule.lock.Lock()
defer recv.agreementModule.lock.Unlock()
recv.ConfirmBlock(block.Hash, votes)
}()
return
}
}
if block.Position.Height != 0 &&
!recv.consensus.bcModule.confirmed(block.Position.Height-1) {
go func(hash common.Hash) {
parentHash := hash
for {
recv.consensus.logger.Warn("Parent block not confirmed",
"parent-hash", parentHash.String()[:6],
"cur-position", block.Position)
ch := make(chan *types.Block)
if !func() bool {
recv.consensus.lock.Lock()
defer recv.consensus.lock.Unlock()
if _, exist := recv.consensus.baConfirmedBlock[parentHash]; exist {
return false
}
recv.consensus.baConfirmedBlock[parentHash] = ch
return true
}() {
return
}
var block *types.Block
PullBlockLoop:
for {
recv.consensus.logger.Debug("Calling Network.PullBlock for parent",
"hash", parentHash)
recv.consensus.network.PullBlocks(common.Hashes{parentHash})
select {
case block = <-ch:
break PullBlockLoop
case <-time.After(1 * time.Second):
}
}
recv.consensus.logger.Info("Receive parent block",
"parent-hash", block.ParentHash.String()[:6],
"cur-position", block.Position)
recv.consensus.processBlockChan <- block
parentHash = block.ParentHash
if block.Position.Height == 0 ||
recv.consensus.bcModule.confirmed(
block.Position.Height-1) {
return
}
}
}(block.ParentHash)
}
if recv.isNotary {
voteList := make([]types.Vote, 0, len(votes))
for _, vote := range votes {
if vote.BlockHash != hash {
continue
}
voteList = append(voteList, *vote)
}
result := &types.AgreementResult{
BlockHash: block.Hash,
Position: block.Position,
Votes: voteList,
IsEmptyBlock: isEmptyBlockConfirmed,
}
recv.consensus.logger.Debug("Propose AgreementResult",
"result", result)
recv.consensus.network.BroadcastAgreementResult(result)
}
recv.consensus.processBlockChan <- block
// Clean the restartNotary channel so BA will not stuck by deadlock.
CleanChannelLoop:
for {
select {
case <-recv.restartNotary:
default:
break CleanChannelLoop
}
}
newPos := block.Position
if block.Timestamp.After(recv.changeNotaryTime) {
newPos.Round++
recv.roundValue.Store(newPos.Round)
}
recv.restartNotary <- newPos
}
func (recv *consensusBAReceiver) PullBlocks(hashes common.Hashes) {
if !recv.isNotary {
return
}
recv.consensus.logger.Debug("Calling Network.PullBlocks", "hashes", hashes)
recv.consensus.network.PullBlocks(hashes)
}
func (recv *consensusBAReceiver) ReportForkVote(v1, v2 *types.Vote) {
recv.consensus.gov.ReportForkVote(v1, v2)
}
func (recv *consensusBAReceiver) ReportForkBlock(b1, b2 *types.Block) {
recv.consensus.gov.ReportForkBlock(b1, b2)
}
// consensusDKGReceiver implements dkgReceiver.
type consensusDKGReceiver struct {
ID types.NodeID
gov Governance
signer *utils.Signer
nodeSetCache *utils.NodeSetCache
cfgModule *configurationChain
network Network
logger common.Logger
}
// ProposeDKGComplaint proposes a DKGComplaint.
func (recv *consensusDKGReceiver) ProposeDKGComplaint(
complaint *typesDKG.Complaint) {
if err := recv.signer.SignDKGComplaint(complaint); err != nil {
recv.logger.Error("Failed to sign DKG complaint", "error", err)
return
}
recv.logger.Debug("Calling Governace.AddDKGComplaint",
"complaint", complaint)
recv.gov.AddDKGComplaint(complaint.Round, complaint)
}
// ProposeDKGMasterPublicKey propose a DKGMasterPublicKey.
func (recv *consensusDKGReceiver) ProposeDKGMasterPublicKey(
mpk *typesDKG.MasterPublicKey) {
if err := recv.signer.SignDKGMasterPublicKey(mpk); err != nil {
recv.logger.Error("Failed to sign DKG master public key", "error", err)
return
}
recv.logger.Debug("Calling Governance.AddDKGMasterPublicKey", "key", mpk)
recv.gov.AddDKGMasterPublicKey(mpk.Round, mpk)
}
// ProposeDKGPrivateShare propose a DKGPrivateShare.
func (recv *consensusDKGReceiver) ProposeDKGPrivateShare(
prv *typesDKG.PrivateShare) {
if err := recv.signer.SignDKGPrivateShare(prv); err != nil {
recv.logger.Error("Failed to sign DKG private share", "error", err)
return
}
receiverPubKey, exists := recv.nodeSetCache.GetPublicKey(prv.ReceiverID)
if !exists {
recv.logger.Error("Public key for receiver not found",
"receiver", prv.ReceiverID.String()[:6])
return
}
if prv.ReceiverID == recv.ID {
go func() {
if err := recv.cfgModule.processPrivateShare(prv); err != nil {
recv.logger.Error("Failed to process self private share", "prvShare", prv)
}
}()
} else {
recv.logger.Debug("Calling Network.SendDKGPrivateShare",
"receiver", hex.EncodeToString(receiverPubKey.Bytes()))
recv.network.SendDKGPrivateShare(receiverPubKey, prv)
}
}
// ProposeDKGAntiNackComplaint propose a DKGPrivateShare as an anti complaint.
func (recv *consensusDKGReceiver) ProposeDKGAntiNackComplaint(
prv *typesDKG.PrivateShare) {
if prv.ProposerID == recv.ID {
if err := recv.signer.SignDKGPrivateShare(prv); err != nil {
recv.logger.Error("Failed sign DKG private share", "error", err)
return
}
}
recv.logger.Debug("Calling Network.BroadcastDKGPrivateShare", "share", prv)
recv.network.BroadcastDKGPrivateShare(prv)
}
// ProposeDKGMPKReady propose a DKGMPKReady message.
func (recv *consensusDKGReceiver) ProposeDKGMPKReady(ready *typesDKG.MPKReady) {
if err := recv.signer.SignDKGMPKReady(ready); err != nil {
recv.logger.Error("Failed to sign DKG ready", "error", err)
return
}
recv.logger.Debug("Calling Governance.AddDKGMPKReady", "ready", ready)
recv.gov.AddDKGMPKReady(ready.Round, ready)
}
// ProposeDKGFinalize propose a DKGFinalize message.
func (recv *consensusDKGReceiver) ProposeDKGFinalize(final *typesDKG.Finalize) {
if err := recv.signer.SignDKGFinalize(final); err != nil {
recv.logger.Error("Failed to sign DKG finalize", "error", err)
return
}
recv.logger.Debug("Calling Governance.AddDKGFinalize", "final", final)
recv.gov.AddDKGFinalize(final.Round, final)
}
// Consensus implements DEXON Consensus algorithm.
type Consensus struct {
// Node Info.
ID types.NodeID
signer *utils.Signer
// BA.
baMgr *agreementMgr
baConfirmedBlock map[common.Hash]chan<- *types.Block
// DKG.
dkgRunning int32
dkgReady *sync.Cond
cfgModule *configurationChain
// Interfaces.
db db.Database
app Application
debugApp Debug
gov Governance
network Network
// Misc.
bcModule *blockChain
dMoment time.Time
nodeSetCache *utils.NodeSetCache
round uint64
roundForNewConfig uint64
lock sync.RWMutex
ctx context.Context
ctxCancel context.CancelFunc
event *common.Event
logger common.Logger
resetRandomnessTicker chan struct{}
resetDeliveryGuardTicker chan struct{}
msgChan chan interface{}
waitGroup sync.WaitGroup
processBlockChan chan *types.Block
// Context of Dummy receiver during switching from syncer.
dummyCancel context.CancelFunc
dummyFinished <-chan struct{}
dummyMsgBuffer []interface{}
}
// NewConsensus construct an Consensus instance.
func NewConsensus(
dMoment time.Time,
app Application,
gov Governance,
db db.Database,
network Network,
prv crypto.PrivateKey,
logger common.Logger) *Consensus {
return newConsensusForRound(
nil, dMoment, app, gov, db, network, prv, logger, true)
}
// NewConsensusForSimulation creates an instance of Consensus for simulation,
// the only difference with NewConsensus is nonblocking of app.
func NewConsensusForSimulation(
dMoment time.Time,
app Application,
gov Governance,
db db.Database,
network Network,
prv crypto.PrivateKey,
logger common.Logger) *Consensus {
return newConsensusForRound(
nil, dMoment, app, gov, db, network, prv, logger, false)
}
// NewConsensusFromSyncer constructs an Consensus instance from information
// provided from syncer.
//
// You need to provide the initial block for this newly created Consensus
// instance to bootstrap with. A proper choice is the last finalized block you
// delivered to syncer.
//
// NOTE: those confirmed blocks should be organized by chainID and sorted by
// their positions, in ascending order.
func NewConsensusFromSyncer(
initBlock *types.Block,
initRoundBeginTime time.Time,
app Application,
gov Governance,
db db.Database,
networkModule Network,
prv crypto.PrivateKey,
confirmedBlocks []*types.Block,
randomnessResults []*types.BlockRandomnessResult,
cachedMessages []interface{},
logger common.Logger) (*Consensus, error) {
// Setup Consensus instance.
con := newConsensusForRound(initBlock, initRoundBeginTime, app, gov, db,
networkModule, prv, logger, true)
// Launch a dummy receiver before we start receiving from network module.
con.dummyMsgBuffer = cachedMessages
con.dummyCancel, con.dummyFinished = utils.LaunchDummyReceiver(
con.ctx, networkModule.ReceiveChan(), func(msg interface{}) {
con.dummyMsgBuffer = append(con.dummyMsgBuffer, msg)
})
// Dump all BA-confirmed blocks to the consensus instance, make sure these
// added blocks forming a DAG.
refBlock := initBlock
for _, b := range confirmedBlocks {
// Only when its parent block is already added to lattice, we can
// then add this block. If not, our pulling mechanism would stop at
// the block we added, and lost its parent block forever.
if b.Position.Height != refBlock.Position.Height+1 {
break
}
if err := con.processBlock(b); err != nil {
return nil, err
}
refBlock = b
}
// Dump all randomness result to the consensus instance.
for _, r := range randomnessResults {
if err := con.ProcessBlockRandomnessResult(r, false); err != nil {
con.logger.Error("failed to process randomness result when syncing",
"result", r)
continue
}
}
return con, nil
}
// newConsensusForRound creates a Consensus instance.
func newConsensusForRound(
initBlock *types.Block,
initRoundBeginTime time.Time,
app Application,
gov Governance,
db db.Database,
network Network,
prv crypto.PrivateKey,
logger common.Logger,
usingNonBlocking bool) *Consensus {
// TODO(w): load latest blockHeight from DB, and use config at that height.
nodeSetCache := utils.NewNodeSetCache(gov)
// Setup signer module.
signer := utils.NewSigner(prv)
// Check if the application implement Debug interface.
var debugApp Debug
if a, ok := app.(Debug); ok {
debugApp = a
}
// Get configuration for bootstrap round.
initRound := uint64(0)
if initBlock != nil {
initRound = initBlock.Position.Round
}
initConfig := utils.GetConfigWithPanic(gov, initRound, logger)
// Init configuration chain.
ID := types.NewNodeID(prv.PublicKey())
recv := &consensusDKGReceiver{
ID: ID,
gov: gov,
signer: signer,
nodeSetCache: nodeSetCache,
network: network,
logger: logger,
}
cfgModule := newConfigurationChain(ID, recv, gov, nodeSetCache, db, logger)
recv.cfgModule = cfgModule
appModule := app
if usingNonBlocking {
appModule = newNonBlocking(app, debugApp)
}
bcConfig := blockChainConfig{}
bcConfig.fromConfig(initRound, initConfig)
bcConfig.setRoundBeginTime(initRoundBeginTime)
bcModule := newBlockChain(ID, initBlock, bcConfig, appModule,
NewTSigVerifierCache(gov, 7), signer, logger)
// Construct Consensus instance.
con := &Consensus{
ID: ID,
app: appModule,
debugApp: debugApp,
gov: gov,
db: db,
network: network,
baConfirmedBlock: make(map[common.Hash]chan<- *types.Block),
dkgReady: sync.NewCond(&sync.Mutex{}),
cfgModule: cfgModule,
bcModule: bcModule,
dMoment: initRoundBeginTime,
nodeSetCache: nodeSetCache,
signer: signer,
event: common.NewEvent(),
logger: logger,
resetRandomnessTicker: make(chan struct{}),
resetDeliveryGuardTicker: make(chan struct{}),
msgChan: make(chan interface{}, 1024),
processBlockChan: make(chan *types.Block, 1024),
}
con.ctx, con.ctxCancel = context.WithCancel(context.Background())
con.baMgr = newAgreementMgr(con, initRound, initRoundBeginTime)
if err := con.prepare(initBlock); err != nil {
panic(err)
}
return con
}
// prepare the Consensus instance to be ready for blocks after 'initBlock'.
// 'initBlock' could be either:
// - nil
// - the last finalized block
func (con *Consensus) prepare(initBlock *types.Block) (err error) {
// The block past from full node should be delivered already or known by
// full node. We don't have to notify it.
initRound := uint64(0)
if initBlock != nil {
initRound = initBlock.Position.Round
}
con.roundForNewConfig = initRound + 1
initConfig := utils.GetConfigWithPanic(con.gov, initRound, con.logger)
// Setup context.
con.logger.Debug("Calling Governance.CRS", "round", initRound)
initCRS := con.gov.CRS(initRound)
if (initCRS == common.Hash{}) {
err = ErrCRSNotReady
return
}
if err = con.baMgr.appendConfig(initRound, initConfig, initCRS); err != nil {
return
}
// Setup blockChain module.
initPlusOneCfg := utils.GetConfigWithPanic(con.gov, initRound+1, con.logger)
if err = con.bcModule.appendConfig(initRound+1, initPlusOneCfg); err != nil {
return
}
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
}
// Run starts running DEXON Consensus.
func (con *Consensus) Run() {
// Launch BA routines.
con.baMgr.run()
// Launch network handler.
con.logger.Debug("Calling Network.ReceiveChan")
con.waitGroup.Add(1)
go con.deliverNetworkMsg()
con.waitGroup.Add(1)
go con.processMsg()
go con.processBlockLoop()
// Sleep until dMoment come.
time.Sleep(con.dMoment.Sub(time.Now().UTC()))
// Take some time to bootstrap.
time.Sleep(3 * time.Second)
con.waitGroup.Add(1)
go con.pullRandomness()
// Stop dummy receiver if launched.
if con.dummyCancel != nil {
con.logger.Trace("Stop dummy receiver")
con.dummyCancel()
<-con.dummyFinished
// Replay those cached messages.
con.logger.Trace("Dummy receiver stoped, start dumping cached messages",
"count", len(con.dummyMsgBuffer))
for _, msg := range con.dummyMsgBuffer {
loop:
for {
select {
case con.msgChan <- msg:
break loop
case <-time.After(50 * time.Millisecond):
con.logger.Debug(
"internal message channel is full when syncing")
}
}
}
con.logger.Trace("Finish dumping cached messages")
}
con.waitGroup.Add(1)
go con.deliveryGuard()
// Block until done.
select {
case <-con.ctx.Done():
}
}
// runDKG starts running DKG protocol.
func (con *Consensus) runDKG(round uint64, config *types.Config) {
con.dkgReady.L.Lock()
defer con.dkgReady.L.Unlock()
if con.dkgRunning != 0 {
return
}
con.dkgRunning = 1
go func() {
startTime := time.Now().UTC()
defer func() {
con.dkgReady.L.Lock()
defer con.dkgReady.L.Unlock()
con.dkgReady.Broadcast()
con.dkgRunning = 2
DKGTime := time.Now().Sub(startTime)
if DKGTime.Nanoseconds() >=
config.RoundInterval.Nanoseconds()/2 {
con.logger.Warn("Your computer cannot finish DKG on time!",
"nodeID", con.ID.String())
}
}()
if err := con.cfgModule.runDKG(round); err != nil {
con.logger.Error("Failed to runDKG", "error", err)
}
}()
}
func (con *Consensus) runCRS(round uint64) {
for {
con.logger.Debug("Calling Governance.CRS to check if already proposed",
"round", round+1)
if (con.gov.CRS(round+1) != common.Hash{}) {
con.logger.Debug("CRS already proposed", "round", round+1)
return
}
con.logger.Debug("Calling Governance.IsDKGFinal to check if ready to run CRS",
"round", round)
if con.cfgModule.isDKGFinal(round) {
break
}
con.logger.Debug("DKG is not ready for running CRS. Retry later...",
"round", round)
time.Sleep(500 * time.Millisecond)
}
// Start running next round CRS.
con.logger.Debug("Calling Governance.CRS", "round", round)
psig, err := con.cfgModule.preparePartialSignature(
round, utils.GetCRSWithPanic(con.gov, round, con.logger))
if err != nil {
con.logger.Error("Failed to prepare partial signature", "error", err)
} else if err = con.signer.SignDKGPartialSignature(psig); err != nil {
con.logger.Error("Failed to sign DKG partial signature", "error", err)
} else if err = con.cfgModule.processPartialSignature(psig); err != nil {
con.logger.Error("Failed to process partial signature", "error", err)
} else {
con.logger.Debug("Calling Network.BroadcastDKGPartialSignature",
"proposer", psig.ProposerID,
"round", psig.Round,
"hash", psig.Hash)
con.network.BroadcastDKGPartialSignature(psig)
con.logger.Debug("Calling Governance.CRS", "round", round)
crs, err := con.cfgModule.runCRSTSig(
round, utils.GetCRSWithPanic(con.gov, round, con.logger))
if err != nil {
con.logger.Error("Failed to run CRS Tsig", "error", err)
} else {
con.logger.Debug("Calling Governance.ProposeCRS",
"round", round+1,
"crs", hex.EncodeToString(crs))
con.gov.ProposeCRS(round+1, crs)
}
}
}
func (con *Consensus) initialRound(
startTime time.Time, round uint64, config *types.Config) {
select {
case <-con.ctx.Done():
return
default:
}
curDkgSet, err := con.nodeSetCache.GetDKGSet(round)
if err != nil {
con.logger.Error("Error getting DKG set", "round", round, "error", err)
curDkgSet = make(map[types.NodeID]struct{})
}
// Initiate CRS routine.
if _, exist := curDkgSet[con.ID]; exist {
con.event.RegisterTime(startTime.Add(config.RoundInterval/2),
func(time.Time) {
go func() {
con.runCRS(round)
}()
})
}
// checkCRS is a generator of checker to check if CRS for that round is
// ready or not.
checkCRS := func(round uint64) func() bool {
return func() bool {
nextCRS := con.gov.CRS(round)
if (nextCRS != common.Hash{}) {
return true
}
con.logger.Debug("CRS is not ready yet. Try again later...",
"nodeID", con.ID,
"round", round)
return false
}
}
// Initiate BA modules.
con.event.RegisterTime(
startTime.Add(config.RoundInterval/2+config.LambdaDKG),
func(time.Time) {
go func(nextRound uint64) {
if !checkWithCancel(
con.ctx, 500*time.Millisecond, checkCRS(nextRound)) {
con.logger.Debug("unable to prepare CRS for baMgr",
"round", nextRound)
return
}
// Notify BA for new round.
nextConfig := utils.GetConfigWithPanic(
con.gov, nextRound, con.logger)
nextCRS := utils.GetCRSWithPanic(
con.gov, nextRound, con.logger)
con.logger.Info("appendConfig for baMgr", "round", nextRound)
if err := con.baMgr.appendConfig(
nextRound, nextConfig, nextCRS); err != nil {
panic(err)
}
}(round + 1)
})
// Initiate DKG for this round.
con.event.RegisterTime(startTime.Add(config.RoundInterval/2+config.LambdaDKG),
func(time.Time) {
go func(nextRound uint64) {
// Normally, gov.CRS would return non-nil. Use this for in case of
// unexpected network fluctuation and ensure the robustness.
if !checkWithCancel(
con.ctx, 500*time.Millisecond, checkCRS(nextRound)) {
con.logger.Debug("unable to prepare CRS for DKG set",
"round", nextRound)
return
}
nextDkgSet, err := con.nodeSetCache.GetDKGSet(nextRound)
if err != nil {
con.logger.Error("Error getting DKG set",
"round", nextRound,
"error", err)
return
}
if _, exist := nextDkgSet[con.ID]; !exist {
return
}
con.logger.Info("Selected as DKG set", "round", nextRound)
con.cfgModule.registerDKG(nextRound, getDKGThreshold(config))
con.event.RegisterTime(
startTime.Add(config.RoundInterval*2/3),
func(time.Time) {
func() {
con.dkgReady.L.Lock()
defer con.dkgReady.L.Unlock()
con.dkgRunning = 0
}()
nextConfig := utils.GetConfigWithPanic(
con.gov, nextRound, con.logger)
con.runDKG(nextRound, nextConfig)
})
}(round + 1)
})
// Prepare blockChain module for next round and next "initialRound" routine.
con.event.RegisterTime(startTime.Add(config.RoundInterval),
func(time.Time) {
// Change round.
// Get configuration for next round.
nextRound := round + 1
nextConfig := utils.GetConfigWithPanic(con.gov, nextRound, con.logger)
con.initialRound(
startTime.Add(config.RoundInterval), nextRound, nextConfig)
})
}
// Stop the Consensus core.
func (con *Consensus) Stop() {
con.ctxCancel()
con.baMgr.stop()
con.event.Reset()
con.waitGroup.Wait()
}
func (con *Consensus) deliverNetworkMsg() {
defer con.waitGroup.Done()
recv := con.network.ReceiveChan()
for {
select {
case <-con.ctx.Done():
return
default:
}
select {
case msg := <-recv:
innerLoop:
for {
select {
case con.msgChan <- msg:
break innerLoop
case <-time.After(500 * time.Millisecond):
con.logger.Debug("internal message channel is full",
"pending", msg)
}
}
case <-con.ctx.Done():
return
}
}
}
func (con *Consensus) processMsg() {
defer con.waitGroup.Done()
MessageLoop:
for {
select {
case <-con.ctx.Done():
return
default:
}
var msg interface{}
select {
case msg = <-con.msgChan:
case <-con.ctx.Done():
return
}
switch val := msg.(type) {
case *types.Block:
if ch, exist := func() (chan<- *types.Block, bool) {
con.lock.RLock()
defer con.lock.RUnlock()
ch, e := con.baConfirmedBlock[val.Hash]
return ch, e
}(); exist {
if err := con.bcModule.sanityCheck(val); err != nil {
if err == ErrRetrySanityCheckLater {
err = nil
} else {
con.logger.Error("SanityCheck failed", "error", err)
continue MessageLoop
}
}
func() {
con.lock.Lock()
defer con.lock.Unlock()
// In case of multiple delivered block.
if _, exist := con.baConfirmedBlock[val.Hash]; !exist {
return
}
delete(con.baConfirmedBlock, val.Hash)
ch <- val
}()
} else if val.IsFinalized() {
// For sync mode.
if err := con.processFinalizedBlock(val); err != nil {
con.logger.Error("Failed to process finalized block",
"block", val,
"error", err)
}
} else {
if err := con.preProcessBlock(val); err != nil {
con.logger.Error("Failed to pre process block",
"block", val,
"error", err)
}
}
case *types.Vote:
if err := con.ProcessVote(val); err != nil {
con.logger.Error("Failed to process vote",
"vote", val,
"error", err)
}
case *types.AgreementResult:
if err := con.ProcessAgreementResult(val); err != nil {
con.logger.Error("Failed to process agreement result",
"result", val,
"error", err)
}
case *types.BlockRandomnessResult:
if err := con.ProcessBlockRandomnessResult(val, true); err != nil {
con.logger.Error("Failed to process block randomness result",
"hash", val.BlockHash.String()[:6],
"position", val.Position,
"error", err)
}
case *typesDKG.PrivateShare:
if err := con.cfgModule.processPrivateShare(val); err != nil {
con.logger.Error("Failed to process private share",
"error", err)
}
case *typesDKG.PartialSignature:
if err := con.cfgModule.processPartialSignature(val); err != nil {
con.logger.Error("Failed to process partial signature",
"error", err)
}
}
}
}
// ProcessVote is the entry point to submit ont vote to a Consensus instance.
func (con *Consensus) ProcessVote(vote *types.Vote) (err error) {
v := vote.Clone()
err = con.baMgr.processVote(v)
return
}
// ProcessAgreementResult processes the randomness request.
func (con *Consensus) ProcessAgreementResult(
rand *types.AgreementResult) error {
if !con.baMgr.touchAgreementResult(rand) {
return nil
}
// Sanity Check.
if err := VerifyAgreementResult(rand, con.nodeSetCache); err != nil {
con.baMgr.untouchAgreementResult(rand)
return err
}
// Syncing BA Module.
if err := con.baMgr.processAgreementResult(rand); err != nil {
return err
}
// Calculating randomness.
if rand.Position.Round == 0 {
return nil
}
// TODO(mission): find a way to avoid spamming by older agreement results.
// Sanity check done.
if !con.cfgModule.touchTSigHash(rand.BlockHash) {
return nil
}
con.logger.Debug("Rebroadcast AgreementResult",
"result", rand)
con.network.BroadcastAgreementResult(rand)
go func() {
dkgSet, err := con.nodeSetCache.GetDKGSet(rand.Position.Round)
if err != nil {
con.logger.Error("Failed to get dkg set",
"round", rand.Position.Round, "error", err)
return
}
if _, exist := dkgSet[con.ID]; !exist {
return
}
psig, err := con.cfgModule.preparePartialSignature(rand.Position.Round, rand.BlockHash)
if err != nil {
con.logger.Error("Failed to prepare psig",
"round", rand.Position.Round,
"hash", rand.BlockHash.String()[:6],
"error", err)
return
}
if err = con.signer.SignDKGPartialSignature(psig); err != nil {
con.logger.Error("Failed to sign psig",
"hash", rand.BlockHash.String()[:6],
"error", err)
return
}
if err = con.cfgModule.processPartialSignature(psig); err != nil {
con.logger.Error("Failed process psig",
"hash", rand.BlockHash.String()[:6],
"error", err)
return
}
con.logger.Debug("Calling Network.BroadcastDKGPartialSignature",
"proposer", psig.ProposerID,
"round", psig.Round,
"hash", psig.Hash.String()[:6])
con.network.BroadcastDKGPartialSignature(psig)
tsig, err := con.cfgModule.runTSig(rand.Position.Round, rand.BlockHash)
if err != nil {
if err != ErrTSigAlreadyRunning {
con.logger.Error("Failed to run TSIG",
"position", rand.Position,
"hash", rand.BlockHash.String()[:6],
"error", err)
}
return
}
result := &types.BlockRandomnessResult{
BlockHash: rand.BlockHash,
Position: rand.Position,
Randomness: tsig.Signature,
}
// ProcessBlockRandomnessResult is not thread-safe so we put the result in
// the message channnel to be processed in the main thread.
con.msgChan <- result
}()
return nil
}
// ProcessBlockRandomnessResult processes the randomness result.
func (con *Consensus) ProcessBlockRandomnessResult(
rand *types.BlockRandomnessResult, needBroadcast bool) error {
if rand.Position.Round == 0 {
return nil
}
if err := con.bcModule.addRandomness(rand); err != nil {
return err
}
if needBroadcast {
con.logger.Debug("Calling Network.BroadcastRandomnessResult",
"randomness", rand)
con.network.BroadcastRandomnessResult(rand)
}
return con.deliverFinalizedBlocks()
}
// preProcessBlock performs Byzantine Agreement on the block.
func (con *Consensus) preProcessBlock(b *types.Block) (err error) {
err = con.baMgr.processBlock(b)
if err == nil && con.debugApp != nil {
con.debugApp.BlockReceived(b.Hash)
}
return
}
func (con *Consensus) pullRandomness() {
defer con.waitGroup.Done()
for {
select {
case <-con.ctx.Done():
return
default:
}
select {
case <-con.ctx.Done():
return
case <-con.resetRandomnessTicker:
case <-time.After(1500 * time.Millisecond):
// TODO(jimmy): pulling period should be related to lambdaBA.
hashes := con.bcModule.pendingBlocksWithoutRandomness()
if len(hashes) > 0 {
con.logger.Debug(
"Calling Network.PullRandomness", "blocks", hashes)
con.network.PullRandomness(hashes)
}
}
}
}
func (con *Consensus) deliveryGuard() {
defer con.waitGroup.Done()
time.Sleep(con.dMoment.Sub(time.Now()))
// Node takes time to start.
time.Sleep(60 * time.Second)
for {
select {
case <-con.ctx.Done():
return
default:
}
select {
case <-con.ctx.Done():
return
case <-con.resetDeliveryGuardTicker:
case <-time.After(60 * time.Second):
con.logger.Error("no blocks delivered for too long", "ID", con.ID)
panic(fmt.Errorf("no blocks delivered for too long"))
}
}
}
// deliverBlock deliver a block to application layer.
func (con *Consensus) deliverBlock(b *types.Block) {
select {
case con.resetRandomnessTicker <- struct{}{}:
default:
}
select {
case con.resetDeliveryGuardTicker <- struct{}{}:
default:
}
// TODO(mission): do we need to put block when confirmed now?
if err := con.db.PutBlock(*b); err != nil {
panic(err)
}
if err := con.db.PutCompactionChainTipInfo(
b.Hash, b.Finalization.Height); err != nil {
panic(err)
}
con.cfgModule.untouchTSigHash(b.Hash)
con.logger.Debug("Calling Application.BlockDelivered", "block", b)
con.app.BlockDelivered(b.Hash, b.Position, b.Finalization.Clone())
if b.Position.Round == con.roundForNewConfig {
// Get configuration for the round next to next round. Configuration
// for that round should be ready at this moment and is required for
// blockChain module. This logic is related to:
// - roundShift
// - notifyGenesisRound
futureRound := con.roundForNewConfig + 1
futureConfig := utils.GetConfigWithPanic(con.gov, futureRound, con.logger)
con.logger.Debug("Append Config", "round", futureRound)
if err := con.bcModule.appendConfig(
futureRound, futureConfig); err != nil {
con.logger.Debug("Unable to append config",
"round", futureRound,
"error", err)
panic(err)
}
con.roundForNewConfig++
}
if con.debugApp != nil {
con.debugApp.BlockReady(b.Hash)
}
}
// deliverFinalizedBlocks extracts and delivers finalized blocks to application
// layer.
func (con *Consensus) deliverFinalizedBlocks() error {
con.lock.Lock()
defer con.lock.Unlock()
return con.deliverFinalizedBlocksWithoutLock()
}
func (con *Consensus) deliverFinalizedBlocksWithoutLock() (err error) {
deliveredBlocks := con.bcModule.extractBlocks()
con.logger.Debug("Last blocks in compaction chain",
"delivered", con.bcModule.lastDeliveredBlock(),
"pending", con.bcModule.lastPendingBlock())
for _, b := range deliveredBlocks {
con.deliverBlock(b)
go con.event.NotifyTime(b.Finalization.Timestamp)
}
return
}
func (con *Consensus) processBlockLoop() {
for {
select {
case <-con.ctx.Done():
return
default:
}
select {
case <-con.ctx.Done():
return
case block := <-con.processBlockChan:
if err := con.processBlock(block); err != nil {
con.logger.Error("Error processing block",
"block", block,
"error", err)
}
}
}
}
// processBlock is the entry point to submit one block to a Consensus instance.
func (con *Consensus) processBlock(block *types.Block) (err error) {
// Block processed by blockChain can be out-of-order. But the output from
// blockChain (deliveredBlocks) cannot, thus we need to protect the part
// below with writer lock.
con.lock.Lock()
defer con.lock.Unlock()
if err = con.bcModule.addBlock(block); err != nil {
return
}
if err = con.deliverFinalizedBlocksWithoutLock(); err != nil {
return
}
return
}
// processFinalizedBlock is the entry point for handling finalized blocks.
func (con *Consensus) processFinalizedBlock(block *types.Block) error {
return con.bcModule.processFinalizedBlock(block)
}
// PrepareBlock would setup header fields of block based on its ProposerID.
func (con *Consensus) proposeBlock(position types.Position) (
*types.Block, error) {
b, err := con.bcModule.proposeBlock(position, time.Now().UTC())
if err != nil {
return nil, err
}
con.logger.Debug("Calling Governance.CRS", "round", b.Position.Round)
crs := con.gov.CRS(b.Position.Round)
if crs.Equal(common.Hash{}) {
con.logger.Error("CRS for round is not ready, unable to prepare block",
"position", &b.Position)
return nil, ErrCRSNotReady
}
if err = con.signer.SignCRS(b, crs); err != nil {
return nil, err
}
if b.IsGenesis() && len(b.Payload) != 0 {
return nil, ErrGenesisBlockNotEmpty
}
return b, nil
}