func (r *Replica) handlePropose(propose *genericsmr.Propose) {
	//TODO!! Handle client retries

	batchSize := len(r.ProposeChan) + 1
	if batchSize > MAX_BATCH {
		batchSize = MAX_BATCH
	}

	instNo := r.crtInstance[r.Id]
	r.crtInstance[r.Id]++

	dlog.Printf("Starting instance %d\n", instNo)
	dlog.Printf("Batching %d\n", batchSize)

	cmds := make([]state.Command, batchSize)
	proposals := make([]*genericsmr.Propose, batchSize)
	cmds[0] = propose.Command
	proposals[0] = propose
	for i := 1; i < batchSize; i++ {
		prop := <-r.ProposeChan
		cmds[i] = prop.Command
		proposals[i] = prop
	}

	r.startPhase1(r.Id, instNo, 0, proposals, cmds, batchSize)
}

func (r *Replica) handlePropose(propose *genericsmr.Propose) {
	if !r.IsLeader {
		preply := &genericsmrproto.ProposeReplyTS{FALSE, -1, state.NIL, 0}
		r.ReplyProposeTS(preply, propose.Reply)
		return
	}

	for r.instanceSpace[r.crtInstance] != nil {
		r.crtInstance++
	}

	instNo := r.crtInstance
	r.crtInstance++

	batchSize := len(r.ProposeChan) + 1

	if batchSize > MAX_BATCH {
		batchSize = MAX_BATCH
	}

	dlog.Printf("Batched %d\n", batchSize)

	cmds := make([]state.Command, batchSize)
	proposals := make([]*genericsmr.Propose, batchSize)
	cmds[0] = propose.Command
	proposals[0] = propose

	for i := 1; i < batchSize; i++ {
		prop := <-r.ProposeChan
		cmds[i] = prop.Command
		proposals[i] = prop
	}

	if r.defaultBallot == -1 {
		r.instanceSpace[instNo] = &Instance{
			cmds,
			r.makeUniqueBallot(0),
			PREPARING,
			&LeaderBookkeeping{proposals, 0, 0, 0, 0}}
		r.bcastPrepare(instNo, r.makeUniqueBallot(0), true)
		dlog.Printf("Classic round for instance %d\n", instNo)
	} else {
		r.instanceSpace[instNo] = &Instance{
			cmds,
			r.defaultBallot,
			PREPARED,
			&LeaderBookkeeping{proposals, 0, 0, 0, 0}}

		r.recordInstanceMetadata(r.instanceSpace[instNo])
		r.recordCommands(cmds)
		r.sync()

		r.bcastAccept(instNo, r.defaultBallot, cmds)
		dlog.Printf("Fast round for instance %d\n", instNo)
	}
}

func (r *Replica) updateBlocking(instance int32) {
	if instance != r.blockingInstance {
		return
	}

	for r.blockingInstance = r.blockingInstance; true; r.blockingInstance++ {
		if r.blockingInstance <= r.skippedTo[int(r.blockingInstance)%r.N] {
			continue
		}
		if r.instanceSpace[r.blockingInstance] == nil {
			return
		}
		inst := r.instanceSpace[r.blockingInstance]
		if inst.status == COMMITTED && inst.skipped {
			r.skippedTo[int(r.blockingInstance)%r.N] = r.blockingInstance + int32((inst.nbInstSkipped-1)*r.N)
			continue
		}
		if inst.status == ACCEPTED && inst.skipped {
			return
		}
		if r.blockingInstance%int32(r.N) == r.Id || inst.lb != nil {
			if inst.status == READY {
				//commit my instance
				dlog.Printf("Am about to commit instance %d\n", r.blockingInstance)

				inst.status = COMMITTED
				if inst.lb.clientProposal != nil && !r.Dreply {
					// give client the all clear
					dlog.Printf("Sending ACK for req. %d\n", inst.lb.clientProposal.CommandId)
					r.ReplyProposeTS(&genericsmrproto.ProposeReplyTS{TRUE, inst.lb.clientProposal.CommandId, state.NIL, inst.lb.clientProposal.Timestamp},
						inst.lb.clientProposal.Reply)
				}
				skip := FALSE
				if inst.skipped {
					skip = TRUE
				}

				r.recordInstanceMetadata(inst)
				r.sync()

				r.bcastCommit(r.blockingInstance, skip, int32(inst.nbInstSkipped), *inst.command)
			} else if inst.status != COMMITTED && inst.status != EXECUTED {
				return
			}
			if inst.skipped {
				r.skippedTo[int(r.blockingInstance)%r.N] = r.blockingInstance + int32((inst.nbInstSkipped-1)*r.N)
			}
		} else {
			if inst.status == PREPARING || (inst.status == ACCEPTED && inst.skipped) {
				return
			}
		}
	}
}

func (r *Replica) handleCommitShort(commit *paxosproto.CommitShort) {
	inst := r.instanceSpace[commit.Instance]

	dlog.Printf("Committing instance %d\n", commit.Instance)

	if inst == nil {
		r.instanceSpace[commit.Instance] = &Instance{nil,
			commit.Ballot,
			COMMITTED,
			nil}
	} else {
		r.instanceSpace[commit.Instance].status = COMMITTED
		r.instanceSpace[commit.Instance].ballot = commit.Ballot
		if inst.lb != nil && inst.lb.clientProposals != nil {
			for i := 0; i < len(inst.lb.clientProposals); i++ {
				r.ProposeChan <- inst.lb.clientProposals[i]
			}
			inst.lb.clientProposals = nil
		}
	}

	r.updateCommittedUpTo()

	r.recordInstanceMetadata(r.instanceSpace[commit.Instance])
}

func (r *Replica) handlePreAcceptOK(pareply *epaxosproto.PreAcceptOK) {
	dlog.Printf("Handling PreAccept reply\n")
	inst := r.InstanceSpace[r.Id][pareply.Instance]

	if inst.Status != epaxosproto.PREACCEPTED {
		// we've moved on, this is a delayed reply
		return
	}

	if !isInitialBallot(inst.ballot) {
		return
	}

	inst.lb.preAcceptOKs++

	allCommitted := true
	for q := 0; q < r.N; q++ {
		if inst.lb.committedDeps[q] < inst.lb.originalDeps[q] {
			inst.lb.committedDeps[q] = inst.lb.originalDeps[q]
		}
		if inst.lb.committedDeps[q] < r.CommittedUpTo[q] {
			inst.lb.committedDeps[q] = r.CommittedUpTo[q]
		}
		if inst.lb.committedDeps[q] < inst.Deps[q] {
			allCommitted = false
		}
	}

	//can we commit on the fast path?
	if inst.lb.preAcceptOKs >= r.N/2 && inst.lb.allEqual && allCommitted && isInitialBallot(inst.ballot) {
		happy++
		r.InstanceSpace[r.Id][pareply.Instance].Status = epaxosproto.COMMITTED
		r.updateCommitted(r.Id)
		if inst.lb.clientProposals != nil && !r.Dreply {
			// give clients the all clear
			for i := 0; i < len(inst.lb.clientProposals); i++ {
				r.ReplyProposeTS(
					&genericsmrproto.ProposeReplyTS{
						TRUE,
						inst.lb.clientProposals[i].CommandId,
						state.NIL,
						inst.lb.clientProposals[i].Timestamp},
					inst.lb.clientProposals[i].Reply)
			}
		}

		r.recordInstanceMetadata(inst)
		r.sync() //is this necessary here?

		r.bcastCommit(r.Id, pareply.Instance, inst.Cmds, inst.Seq, inst.Deps)
	} else if inst.lb.preAcceptOKs >= r.N/2 {
		if !allCommitted {
			weird++
		}
		slow++
		inst.Status = epaxosproto.ACCEPTED
		r.bcastAccept(r.Id, pareply.Instance, inst.ballot, int32(len(inst.Cmds)), inst.Seq, inst.Deps)
	}
	//TODO: take the slow path if messages are slow to arrive
}

func (r *Replica) handleCommit(commit *lpaxosproto.Commit) {
	inst := r.InstanceSpace[commit.Instance]

	dlog.Printf("Committing instance %d\n", commit.Instance)

	if inst == nil {
		r.InstanceSpace[commit.Instance] = &Instance{
			commit.LeaseUpdate,
			commit.Ballot,
			COMMITTED,
			nil}
	} else {
		r.InstanceSpace[commit.Instance].Updates = commit.LeaseUpdate
		r.InstanceSpace[commit.Instance].Status = COMMITTED
		r.InstanceSpace[commit.Instance].ballot = commit.Ballot
		//try to propose in a different instance or just give up?
	}

	if r.LatestCommitted < commit.Instance {
		r.LatestCommitted = commit.Instance
	}

	/*r.recordInstanceMetadata(r.InstanceSpace[commit.Instance])
	  r.recordUpdates(commit.Updates)*/
}

func (r *Replica) handleCommit(commit *paxosproto.Commit) {
	inst := r.instanceSpace[commit.Instance]

	dlog.Printf("Committing instance %d\n", commit.Instance)

	if inst == nil {
		r.instanceSpace[commit.Instance] = &Instance{
			commit.Command,
			commit.Ballot,
			COMMITTED,
			nil,
			0, false}
		r.addUpdatingKeys(commit.Command)
	} else {
		r.instanceSpace[commit.Instance].cmds = commit.Command
		r.instanceSpace[commit.Instance].status = COMMITTED
		r.instanceSpace[commit.Instance].ballot = commit.Ballot
		if inst.lb != nil && inst.lb.clientProposals != nil {
			for i := 0; i < len(inst.lb.clientProposals); i++ {
				r.ProposeChan <- inst.lb.clientProposals[i]
			}
			inst.lb.clientProposals = nil
		}
	}

	if commit.Instance > r.latestAcceptedInst {
		r.latestAcceptedInst = commit.Instance
	}

	r.updateCommittedUpTo()

	r.recordInstanceMetadata(r.instanceSpace[commit.Instance])
	r.recordCommands(commit.Command)
}

func (r *Replica) handleAcceptReply(areply *menciusproto.AcceptReply) {
	dlog.Printf("AcceptReply for instance %d\n", areply.Instance)

	inst := r.instanceSpace[areply.Instance]

	if areply.OK == TRUE {
		inst.lb.acceptOKs++
		if areply.SkippedStartInstance > -1 {
			r.instanceSpace[areply.SkippedStartInstance] = &Instance{true,
				int(areply.SkippedEndInstance-areply.SkippedStartInstance)/r.N + 1,
				nil,
				0,
				COMMITTED,
				nil}
			r.updateBlocking(areply.SkippedStartInstance)
		}

		if inst.status == COMMITTED || inst.status == EXECUTED { //TODO || aargs.Ballot != inst.ballot {
			// we've moved on, these are delayed replies, so just ignore
			return
		}

		if inst.lb.acceptOKs+1 > r.N>>1 {
			if inst.skipped {
				//TODO what if
			}
			inst.status = READY
			if !inst.skipped && areply.Instance > r.latestInstReady {
				r.latestInstReady = areply.Instance
			}
			r.updateBlocking(areply.Instance)
		}
	} else {
		// TODO: there is probably another active leader
		inst.lb.nacks++
		if areply.Ballot > inst.lb.maxRecvBallot {
			inst.lb.maxRecvBallot = areply.Ballot
		}
		if (areply.Ballot&0x0F)%int32(r.N) == areply.Instance%int32(r.N) {
			// the owner of the instance is trying to commit something, I should give up
		}
		if inst.lb.nacks >= r.N>>1 {
			// TODO
			if inst.lb.clientProposal != nil {
				// I'm the owner of the instance, I'll try again with a higher ballot number
				inst.ballot = r.makeBallotLargerThan(inst.lb.maxRecvBallot)
				r.bcastPrepare(areply.Instance, inst.ballot)
			}
		}
	}
}

func (r *Replica) handleProposeLease(propose *lpaxosproto.ProposeLease) {
	if !r.IsLeader {
		//TODO: should notify sender? not necessary, but may speed things up
		return
	}

	for r.InstanceSpace[r.crtInstance] != nil {
		r.crtInstance++
	}

	instNo := r.crtInstance
	r.crtInstance++

	if r.defaultBallot == -1 {
		r.InstanceSpace[instNo] = &Instance{
			propose.Updates,
			r.makeUniqueBallot(0),
			PREPARING,
			&LeaderBookkeeping{0, 0, 0, 0}}
		r.bcastPrepare(instNo, r.makeUniqueBallot(0), true)
		dlog.Printf("Classic round for instance %d\n", instNo)
	} else {
		r.InstanceSpace[instNo] = &Instance{
			propose.Updates,
			r.defaultBallot,
			PREPARED,
			&LeaderBookkeeping{0, 0, 0, 0}}

		/*r.recordInstanceMetadata(r.InstanceSpace[instNo])
		  r.recordCommands(cmds)
		  r.sync()*/

		r.bcastAccept(instNo, r.defaultBallot, propose.Updates)
		dlog.Printf("Fast round for instance %d\n", instNo)
	}
}

func (r *Replica) handlePrepareReply(preply *menciusproto.PrepareReply) {
	dlog.Printf("PrepareReply for instance %d\n", preply.Instance)

	inst := r.instanceSpace[preply.Instance]

	if inst.status != PREPARING {
		// we've moved on -- these are delayed replies, so just ignore
		return
	}

	if preply.OK == TRUE {
		inst.lb.prepareOKs++

		if preply.Ballot > inst.lb.maxRecvBallot {
			inst.command = &preply.Command
			inst.skipped = false
			if preply.Skip == TRUE {
				inst.skipped = true
			}
			inst.nbInstSkipped = int(preply.NbInstancesToSkip)
			inst.lb.maxRecvBallot = preply.Ballot
		}

		if inst.lb.prepareOKs+1 > r.N>>1 {
			inst.status = ACCEPTED
			inst.lb.nacks = 0
			skip := FALSE
			if inst.skipped {
				skip = TRUE
			}
			r.bcastAccept(preply.Instance, inst.ballot, skip, int32(inst.nbInstSkipped), *inst.command)
		}
	} else {
		// TODO: there is probably another active leader
		inst.lb.nacks++
		if preply.Ballot > inst.lb.maxRecvBallot {
			inst.lb.maxRecvBallot = preply.Ballot
		}
		if inst.lb.nacks >= r.N>>1 && inst.lb != nil {
			// TODO: better to wait a while
			// some other replica is trying to commit skips for our instance
			// increase ballot number and try again
			inst.ballot = r.makeBallotLargerThan(inst.lb.maxRecvBallot)
			r.bcastPrepare(preply.Instance, inst.ballot)
		}
	}
}

func (r *Replica) handlePropose(propose *genericsmr.Propose) {

	instNo := r.crtInstance
	r.crtInstance += int32(r.N)

	r.instanceSpace[instNo] = &Instance{false,
		0,
		&propose.Command,
		r.makeBallotLargerThan(0),
		ACCEPTED,
		&LeaderBookkeeping{propose, 0, 0, 0, 0}}

	r.recordInstanceMetadata(r.instanceSpace[instNo])
	r.recordCommand(&propose.Command)
	r.sync()

	r.bcastAccept(instNo, r.instanceSpace[instNo].ballot, FALSE, 0, propose.Command)
	dlog.Printf("Choosing req. %d in instance %d\n", propose.CommandId, instNo)
}

func (r *Replica) handleCommit(commit *menciusproto.Commit) {
	inst := r.instanceSpace[commit.Instance]

	dlog.Printf("Committing instance %d\n", commit.Instance)

	if inst == nil {
		skip := false
		if commit.Skip == TRUE {
			skip = true
		}
		r.instanceSpace[commit.Instance] = &Instance{skip,
			int(commit.NbInstancesToSkip),
			nil, //&commit.Command,
			0,
			COMMITTED,
			nil}
	} else {
		//inst.command = &commit.Command
		inst.status = COMMITTED
		inst.skipped = false
		if commit.Skip == TRUE {
			inst.skipped = true
		}
		inst.nbInstSkipped = int(commit.NbInstancesToSkip)
		if inst.lb != nil && inst.lb.clientProposal != nil {
			// try command in the next available instance
			r.ProposeChan <- inst.lb.clientProposal
			inst.lb.clientProposal = nil
		}
	}

	r.recordInstanceMetadata(r.instanceSpace[commit.Instance])

	if commit.Instance%int32(r.N) == r.Id%int32(r.N) {
		if r.crtInstance < commit.Instance+commit.NbInstancesToSkip*int32(r.N) {
			r.crtInstance = commit.Instance + commit.NbInstancesToSkip*int32(r.N)
		}
	}

	// Try to commit instances waiting for this one
	r.updateBlocking(commit.Instance)
}

func (r *Replica) handle2b(msg *gpaxosproto.M_2b) {
	if msg.Balnum != r.crtBalnum {
		dlog.Println("2b from a different ballot")
		return
	}

	crtbal := r.ballotArray[r.crtBalnum]

	if r.isLeader && crtbal.status != PHASE2 {
		log.Println("2b before its time")
		return
	}

	crtbal.lb.cstructs[msg.ReplicaId] = msg.Cstruct
	dlog.Printf("Replica %d 2b msg.Cstruct: ", msg.ReplicaId)
	dlog.Println(msg.Cstruct)
	dlog.Println("my cstruct:", crtbal.cstruct)

	crtbal.lb.cstructs[r.Id] = crtbal.cstruct

	r.tryToLearn()
}

func (r *Replica) handleCommitShort(commit *lpaxosproto.CommitShort) {
	inst := r.InstanceSpace[commit.Instance]

	if inst != nil && inst.Updates != nil {
		log.Printf("Lease update commit at replica %d\n", r.Id)
	}

	dlog.Printf("Committing instance %d\n", commit.Instance)

	if inst == nil {
		r.InstanceSpace[commit.Instance] = &Instance{nil,
			commit.Ballot,
			COMMITTED,
			nil}
	} else {
		r.InstanceSpace[commit.Instance].Status = COMMITTED
		r.InstanceSpace[commit.Instance].ballot = commit.Ballot
		if r.LatestCommitted < commit.Instance {
			r.LatestCommitted = commit.Instance
		}
		//try to propose in a different instance or just give up?
	}
	//r.recordInstanceMetadata(r.InstanceSpace[commit.Instance])
}

func (r *Replica) run() {

	r.ConnectToPeers()

	dlog.Println("Waiting for client connections")

	go r.WaitForClientConnections()

	if r.Exec {
		go r.executeCommands()
	}

	if r.Id == 0 {
		r.IsLeader = true
	}

	clockChan = make(chan bool, 1)
	go r.clock()

	clockRang := false

	for !r.Shutdown {

		select {

		case <-clockChan:
			clockRang = true
			break

		case prepareS := <-r.prepareChan:
			prepare := prepareS.(*paxosproto.Prepare)
			//got a Prepare message
			dlog.Printf("Received Prepare from replica %d, for instance %d\n", prepare.LeaderId, prepare.Instance)
			r.handlePrepare(prepare)
			break

		case acceptS := <-r.acceptChan:
			accept := acceptS.(*paxosproto.Accept)
			//got an Accept message
			dlog.Printf("Received Accept from replica %d, for instance %d\n", accept.LeaderId, accept.Instance)
			r.handleAccept(accept)
			break

		case commitS := <-r.commitChan:
			commit := commitS.(*paxosproto.Commit)
			//got a Commit message
			dlog.Printf("Received Commit from replica %d, for instance %d\n", commit.LeaderId, commit.Instance)
			r.handleCommit(commit)
			break

		case commitS := <-r.commitShortChan:
			commit := commitS.(*paxosproto.CommitShort)
			//got a Commit message
			dlog.Printf("Received Commit from replica %d, for instance %d\n", commit.LeaderId, commit.Instance)
			r.handleCommitShort(commit)
			break

		case prepareReplyS := <-r.prepareReplyChan:
			prepareReply := prepareReplyS.(*paxosproto.PrepareReply)
			//got a Prepare reply
			dlog.Printf("Received PrepareReply for instance %d\n", prepareReply.Instance)
			r.handlePrepareReply(prepareReply)
			break

		case acceptReplyS := <-r.acceptReplyChan:
			acceptReply := acceptReplyS.(*paxosproto.AcceptReply)
			//got an Accept reply
			dlog.Printf("Received AcceptReply for instance %d\n", acceptReply.Instance)
			r.handleAcceptReply(acceptReply)
			break
		}

		if clockRang {
			select {

			case propose := <-r.ProposeChan:
				//got a Propose from a client
				dlog.Printf("Proposal with op %d\n", propose.Command.Op)
				r.handlePropose(propose)
				clockRang = false
				break

			case prepareS := <-r.prepareChan:
				prepare := prepareS.(*paxosproto.Prepare)
				//got a Prepare message
				dlog.Printf("Received Prepare from replica %d, for instance %d\n", prepare.LeaderId, prepare.Instance)
				r.handlePrepare(prepare)
				break

			case acceptS := <-r.acceptChan:
				accept := acceptS.(*paxosproto.Accept)
				//got an Accept message
				dlog.Printf("Received Accept from replica %d, for instance %d\n", accept.LeaderId, accept.Instance)
				r.handleAccept(accept)
				break

			case commitS := <-r.commitChan:
				commit := commitS.(*paxosproto.Commit)
				//got a Commit message
				dlog.Printf("Received Commit from replica %d, for instance %d\n", commit.LeaderId, commit.Instance)
//.........这里部分代码省略.........

func (r *Replica) executeCommands() {
	execedUpTo := int32(-1)
	skippedTo := make([]int32, r.N)
	skippedToOrig := make([]int32, r.N)
	conflicts := make(map[state.Key]int32, 60000)

	for q := 0; q < r.N; q++ {
		skippedToOrig[q] = -1
	}

	for !r.Shutdown {
		executed := false
		jump := false
		copy(skippedTo, skippedToOrig)
		for i := execedUpTo + 1; i < r.crtInstance; i++ {
			if i < skippedTo[i%int32(r.N)] {
				continue
			}

			if r.instanceSpace[i] == nil {
				break
			}

			if r.instanceSpace[i].status == EXECUTED {
				continue
			}

			if r.instanceSpace[i].status != COMMITTED {
				if !r.instanceSpace[i].skipped {
					confInst, present := conflicts[r.instanceSpace[i].command.K]
					if present && r.instanceSpace[confInst].status != EXECUTED {
						break
					}
					conflicts[r.instanceSpace[i].command.K] = i
					jump = true
					continue
				} else {
					break
				}
			}

			if r.instanceSpace[i].skipped {
				skippedTo[i%int32(r.N)] = i + int32(r.instanceSpace[i].nbInstSkipped*r.N)
				if !jump {
					skippedToOrig[i%int32(r.N)] = skippedTo[i%int32(r.N)]
				}
				continue
			}

			inst := r.instanceSpace[i]
			for inst.command == nil {
				time.Sleep(1000 * 1000)
			}
			confInst, present := conflicts[inst.command.K]
			if present && confInst < i && r.instanceSpace[confInst].status != EXECUTED && state.Conflict(r.instanceSpace[confInst].command, inst.command) {
				break
			}

			inst.command.Execute(r.State)

			if r.Dreply && inst.lb != nil && inst.lb.clientProposal != nil {
				dlog.Printf("Sending ACK for req. %d\n", inst.lb.clientProposal.CommandId)
				r.ReplyProposeTS(&genericsmrproto.ProposeReplyTS{TRUE, inst.lb.clientProposal.CommandId, state.NIL, inst.lb.clientProposal.Timestamp},
					inst.lb.clientProposal.Reply)
			}
			inst.status = EXECUTED

			executed = true

			if !jump {
				execedUpTo = i
			}
		}
		if !executed {
			time.Sleep(1000 * 1000)
		}
	}
}

func (r *Replica) run() {
	r.ConnectToPeers()

	dlog.Println("Waiting for client connections")

	go r.WaitForClientConnections()

	if r.Exec {
		go r.executeCommands()
	}

	if r.Id == 0 {
		//init quorum read lease
		quorum := make([]int32, r.N/2+1)
		for i := 0; i <= r.N/2; i++ {
			quorum[i] = int32(i)
		}
		r.UpdatePreferredPeerOrder(quorum)
	}

	slowClockChan = make(chan bool, 1)
	fastClockChan = make(chan bool, 1)
	go r.slowClock()

	//Enabled when batching for 5ms
	if MAX_BATCH > 100 {
		go r.fastClock()
	}

	if r.Beacon {
		go r.stopAdapting()
	}

	for !r.Shutdown {

		handleNewProposals := true

		// Enabled when batching for 5ms
		if MAX_BATCH > 100 {
			handleNewProposals = false
		}

		select {

		case <-fastClockChan:
			handleNewProposals = true
			break

		case prepareS := <-r.prepareChan:
			prepare := prepareS.(*epaxosproto.Prepare)
			//got a Prepare message
			dlog.Printf("Received Prepare for instance %d.%d\n", prepare.Replica, prepare.Instance)
			r.handlePrepare(prepare)
			break

		case preAcceptS := <-r.preAcceptChan:
			preAccept := preAcceptS.(*epaxosproto.PreAccept)
			//got a PreAccept message
			dlog.Printf("Received PreAccept for instance %d.%d\n", preAccept.LeaderId, preAccept.Instance)
			r.handlePreAccept(preAccept)
			break

		case acceptS := <-r.acceptChan:
			accept := acceptS.(*epaxosproto.Accept)
			//got an Accept message
			dlog.Printf("Received Accept for instance %d.%d\n", accept.LeaderId, accept.Instance)
			r.handleAccept(accept)
			break

		case commitS := <-r.commitChan:
			commit := commitS.(*epaxosproto.Commit)
			//got a Commit message
			dlog.Printf("Received Commit for instance %d.%d\n", commit.LeaderId, commit.Instance)
			r.handleCommit(commit)
			break

		case commitS := <-r.commitShortChan:
			commit := commitS.(*epaxosproto.CommitShort)
			//got a Commit message
			dlog.Printf("Received Commit for instance %d.%d\n", commit.LeaderId, commit.Instance)
			r.handleCommitShort(commit)
			break

		case prepareReplyS := <-r.prepareReplyChan:
			prepareReply := prepareReplyS.(*epaxosproto.PrepareReply)
			//got a Prepare reply
			dlog.Printf("Received PrepareReply for instance %d.%d\n", prepareReply.Replica, prepareReply.Instance)
			r.handlePrepareReply(prepareReply)
			break

		case preAcceptReplyS := <-r.preAcceptReplyChan:
			preAcceptReply := preAcceptReplyS.(*epaxosproto.PreAcceptReply)
			//got a PreAccept reply
			dlog.Printf("Received PreAcceptReply for instance %d.%d\n", preAcceptReply.Replica, preAcceptReply.Instance)
			r.handlePreAcceptReply(preAcceptReply)
			break

		case preAcceptOKS := <-r.preAcceptOKChan:
			preAcceptOK := preAcceptOKS.(*epaxosproto.PreAcceptOK)
			//got a PreAccept reply
//.........这里部分代码省略.........

func (r *Replica) run() {
	r.ConnectToPeers()

	dlog.Println("Waiting for client connections")

	go r.WaitForClientConnections()

	if r.Exec {
		go r.executeCommands()
	}

	go r.clock()

	for !r.Shutdown {

		select {

		case propose := <-r.ProposeChan:
			//got a Propose from a client
			dlog.Printf("Proposal with id %d\n", propose.CommandId)
			r.handlePropose(propose)
			break

		case skipS := <-r.skipChan:
			skip := skipS.(*menciusproto.Skip)
			//got a Skip from another replica
			dlog.Printf("Skip for instances %d-%d\n", skip.StartInstance, skip.EndInstance)
			r.handleSkip(skip)

		case prepareS := <-r.prepareChan:
			prepare := prepareS.(*menciusproto.Prepare)
			//got a Prepare message
			dlog.Printf("Received Prepare from replica %d, for instance %d\n", prepare.LeaderId, prepare.Instance)
			r.handlePrepare(prepare)
			break

		case acceptS := <-r.acceptChan:
			accept := acceptS.(*menciusproto.Accept)
			//got an Accept message
			dlog.Printf("Received Accept from replica %d, for instance %d\n", accept.LeaderId, accept.Instance)
			r.handleAccept(accept)
			break

		case commitS := <-r.commitChan:
			commit := commitS.(*menciusproto.Commit)
			//got a Commit message
			dlog.Printf("Received Commit from replica %d, for instance %d\n", commit.LeaderId, commit.Instance)
			r.handleCommit(commit)
			break

		case prepareReplyS := <-r.prepareReplyChan:
			prepareReply := prepareReplyS.(*menciusproto.PrepareReply)
			//got a Prepare reply
			dlog.Printf("Received PrepareReply for instance %d\n", prepareReply.Instance)
			r.handlePrepareReply(prepareReply)
			break

		case acceptReplyS := <-r.acceptReplyChan:
			acceptReply := acceptReplyS.(*menciusproto.AcceptReply)
			//got an Accept reply
			dlog.Printf("Received AcceptReply for instance %d\n", acceptReply.Instance)
			r.handleAcceptReply(acceptReply)
			break

		case delayedSkip := <-r.delayedSkipChan:
			r.handleDelayedSkip(delayedSkip)
			break

		case <-r.clockChan:
			if lastSeenInstance == r.blockingInstance {
				r.noCommitFor++
			} else {
				r.noCommitFor = 0
				lastSeenInstance = r.blockingInstance
			}
			if r.noCommitFor >= 50+int(r.Id) && r.crtInstance >= r.blockingInstance+int32(r.N) {
				r.noCommitFor = 0
				dlog.Printf("Doing force commit\n")
				r.forceCommit()
			}
			break
		}
	}
}

func (r *Replica) handlePreAcceptReply(pareply *epaxosproto.PreAcceptReply) {
	dlog.Printf("Handling PreAccept reply\n")
	inst := r.InstanceSpace[pareply.Replica][pareply.Instance]

	if inst.Status != epaxosproto.PREACCEPTED {
		// we've moved on, this is a delayed reply
		return
	}

	if inst.ballot != pareply.Ballot {
		return
	}

	if pareply.OK == FALSE {
		// TODO: there is probably another active leader
		inst.lb.nacks++
		if pareply.Ballot > inst.lb.maxRecvBallot {
			inst.lb.maxRecvBallot = pareply.Ballot
		}
		if inst.lb.nacks >= r.N/2 {
			// TODO
		}
		return
	}

	inst.lb.preAcceptOKs++

	var equal bool
	inst.Seq, inst.Deps, equal = r.mergeAttributes(inst.Seq, inst.Deps, pareply.Seq, pareply.Deps)
	if (r.N <= 3 && !r.Thrifty) || inst.lb.preAcceptOKs > 1 {
		inst.lb.allEqual = inst.lb.allEqual && equal
		if !equal {
			conflicted++
		}
	}

	allCommitted := true
	for q := 0; q < r.N; q++ {
		if inst.lb.committedDeps[q] < pareply.CommittedDeps[q] {
			inst.lb.committedDeps[q] = pareply.CommittedDeps[q]
		}
		if inst.lb.committedDeps[q] < r.CommittedUpTo[q] {
			inst.lb.committedDeps[q] = r.CommittedUpTo[q]
		}
		if inst.lb.committedDeps[q] < inst.Deps[q] {
			allCommitted = false
		}
	}

	//can we commit on the fast path?
	if inst.lb.preAcceptOKs >= r.N/2 && inst.lb.allEqual && allCommitted && isInitialBallot(inst.ballot) {
		happy++
		dlog.Printf("Fast path for instance %d.%d\n", pareply.Replica, pareply.Instance)
		r.InstanceSpace[pareply.Replica][pareply.Instance].Status = epaxosproto.COMMITTED
		r.updateCommitted(pareply.Replica)
		if inst.lb.clientProposals != nil && !r.Dreply {
			// give clients the all clear
			for i := 0; i < len(inst.lb.clientProposals); i++ {
				r.ReplyProposeTS(
					&genericsmrproto.ProposeReplyTS{
						TRUE,
						inst.lb.clientProposals[i].CommandId,
						state.NIL,
						inst.lb.clientProposals[i].Timestamp},
					inst.lb.clientProposals[i].Reply)
			}
		}

		r.recordInstanceMetadata(inst)
		r.sync() //is this necessary here?

		r.bcastCommit(pareply.Replica, pareply.Instance, inst.Cmds, inst.Seq, inst.Deps)
	} else if inst.lb.preAcceptOKs >= r.N/2 {
		if !allCommitted {
			weird++
		}
		slow++
		inst.Status = epaxosproto.ACCEPTED
		r.bcastAccept(pareply.Replica, pareply.Instance, inst.ballot, int32(len(inst.Cmds)), inst.Seq, inst.Deps)
	}
	//TODO: take the slow path if messages are slow to arrive
}

func (r *Replica) handleAccept(accept *menciusproto.Accept) {
	flush := true
	inst := r.instanceSpace[accept.Instance]

	if inst != nil && inst.ballot > accept.Ballot {
		r.replyAccept(accept.LeaderId, &menciusproto.AcceptReply{accept.Instance, FALSE, inst.ballot, -1, -1})
		return
	}

	skipStart := int32(-1)
	skipEnd := int32(-1)
	if accept.Skip == FALSE && r.crtInstance < accept.Instance {
		skipStart = r.crtInstance
		skipEnd = accept.Instance/int32(r.N)*int32(r.N) + r.Id
		if skipEnd > accept.Instance {
			skipEnd -= int32(r.N)
		}
		if r.skipsWaiting < MAX_SKIPS_WAITING {
			//start a timer, waiting for a propose to arrive and fill this hole
			go r.timerHelper(&DelayedSkip{skipEnd})
			//r.delayedSkipChan <- &DelayedSkip{accept, skipStart}
			r.skipsWaiting++
			flush = false
		}
		r.instanceSpace[r.crtInstance] = &Instance{true,
			int(skipEnd-r.crtInstance)/r.N + 1,
			nil,
			-1,
			COMMITTED,
			nil}

		r.recordInstanceMetadata(r.instanceSpace[r.crtInstance])
		r.sync()

		r.crtInstance = skipEnd + int32(r.N)
	}
	if inst == nil {
		skip := false
		if accept.Skip == TRUE {
			skip = true
		}
		r.instanceSpace[accept.Instance] = &Instance{skip,
			int(accept.NbInstancesToSkip),
			&accept.Command,
			accept.Ballot,
			ACCEPTED,
			nil}
		r.recordInstanceMetadata(r.instanceSpace[accept.Instance])
		r.recordCommand(&accept.Command)
		r.sync()

		r.replyAccept(accept.LeaderId, &menciusproto.AcceptReply{accept.Instance, TRUE, -1, skipStart, skipEnd})
	} else {
		if inst.status == COMMITTED || inst.status == EXECUTED {
			if inst.command == nil {
				inst.command = &accept.Command
			}
			dlog.Printf("ATTENTION! Reordered Commit\n")
		} else {
			inst.command = &accept.Command
			inst.ballot = accept.Ballot
			inst.status = ACCEPTED
			inst.skipped = false
			if accept.Skip == TRUE {
				inst.skipped = true
			}
			inst.nbInstSkipped = int(accept.NbInstancesToSkip)

			r.recordInstanceMetadata(inst)

			r.replyAccept(accept.LeaderId, &menciusproto.AcceptReply{accept.Instance, TRUE, inst.ballot, skipStart, skipEnd})
		}
	}
	if skipStart >= 0 {
		dlog.Printf("Skipping!!\n")
		r.bcastSkip(skipStart, skipEnd, accept.LeaderId)
		r.updateBlocking(skipStart)
		if flush {
			for _, w := range r.PeerWriters {
				if w != nil {
					w.Flush()
				}
			}
		}
	} else {
		r.updateBlocking(accept.Instance)
	}
}