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/*
Consensus State Machine Overview:
NewHeight, NewRound, Propose, Prevote, Precommit represent state machine steps. (aka RoundStep).
To "prevote/precommit" something means to broadcast a prevote/precommit vote for something.
During NewHeight/NewRound/Propose/Prevote/Precommit:
* Nodes gossip the proposal block proposed by the designated proposer at round.
* Nodes gossip prevotes/precommits at rounds [0...currentRound+1] (currentRound+1 to allow round-skipping)
* Nodes gossip prevotes for the proposal's POL (proof-of-lock) round if proposed.
* Nodes gossip to late nodes (lagging in height) with precommits of the commit round (aka catchup)
Upon each state transition, the height/round/step is broadcast to neighboring peers.
The set of +2/3 of precommits at the same round for the same block is called a Commit, or Validation.
A block contains the last block's Validation, which includes the Commit precommits.
While all the precommits in the Validation are from the same height & round (ordered by validator index),
some precommits may be <nil> (if the validator's precommit vote didn't reach the proposer in time),
or some precommits may be for different blockhashes for the last block hash (which is fine).
Each unlock/change-of-lock should be justifiable by an POL where +2/3 prevoted for
some block or <nil> at some round.
POL = Proof-of-Lock = +2/3 prevotes for block B (or +2/3 prevotes for <nil>) at (H,R)
lockRound < POLRound <= unlockOrChangeLockRound
Without the POLRound <= unlockOrChangeLockRound condition, an unlock would be possible from a
future condition that hasn't happened yet, so it destroys deterministic accountability.
With lockRound < POLRound <= unlockOrChangeLockRound, blame can be shifted to lower rounds.
* NewRound(height:H,round:R):
* Set up new round. --> goto Propose(H,R)
* NOTE: Not much happens in this step. It exists for clarity.
* Propose(height:H,round:R):
* Upon entering Propose:
* The designated proposer proposes a block at (H,R).
* The Propose step ends:
* After `timeoutPropose` after entering Propose. --> goto Prevote(H,R)
* After receiving proposal block and all POL prevotes. --> goto Prevote(H,R)
* After any +2/3 prevotes received at (H,R+1). --> goto Prevote(H,R+1)
* After any +2/3 precommits received at (H,R+1). --> goto Precommit(H,R+1)
* After +2/3 precommits received for a particular block. --> goto Commit(H)
* Prevote(height:H,round:R):
* Upon entering Prevote, each validator broadcasts its prevote vote.
* If the validator is locked on a block, it prevotes that.
* Else, if the proposed block from Propose(H,R) is good, it prevotes that.
* Else, if the proposal is invalid or wasn't received on time, it prevotes <nil>.
* The Prevote step ends:
* After +2/3 prevotes for a particular block or <nil>. --> goto Precommit(H,R)
* After `timeoutPrevote` after receiving any +2/3 prevotes. --> goto Precommit(H,R)
* After any +2/3 prevotes received at (H,R+1). --> goto Prevote(H,R+1)
* After any +2/3 precommits received at (H,R+1). --> goto Precommit(H,R+1)
* After +2/3 precommits received for a particular block. --> goto Commit(H)
* Precommit(height:H,round:R):
* Upon entering Precommit, each validator broadcasts its precommit vote.
* If the validator had seen +2/3 of prevotes for a particular block from Prevote(H,R),
it locks (changes lock to) that block and precommits that block.
* Else, if the validator had seen +2/3 of prevotes for <nil>, it unlocks and precommits <nil>.
* Else, if +2/3 of prevotes for a particular block or <nil> is not received on time,
it precommits what it's locked on, or <nil>.
* The Precommit step ends:
* After +2/3 precommits for a particular block. --> goto Commit(H)
* After +2/3 precommits for <nil>. --> goto NewRound(H,R+1)
* After `timeoutPrecommit` after receiving any +2/3 precommits. --> goto NewRound(H,R+1)
* After any +2/3 prevotes received at (H,R+1). --> goto Prevote(H,R+1)
* After any +2/3 precommits received at (H,R+1). --> goto Precommit(H,R+1)
* Commit(height:H):
* Set CommitTime = now
* Wait until block is received. --> goto NewHeight(H+1)
* NewHeight(height:H):
* Move Precommits to LastCommit and increment height.
* Set StartTime = CommitTime+timeoutCommit
* Wait until `StartTime` to receive straggler commits. --> goto NewRound(H,0)
* Proof of Safety:
If a good validator commits at round R, it's because it saw +2/3 of precommits at round R.
This implies that (assuming tolerance bounds) +1/3 of honest nodes are still locked at round R+1.
These locked validators will remain locked until they see +2/3 prevote for something
else, but this won't happen because +1/3 are locked and honest.
* Proof of Liveness:
Lemma 1: If +1/3 good nodes are locked on two different blocks, the proposers' POLRound will
eventually cause nodes locked from the earlier round to unlock.
-> `timeoutProposalR` increments with round R, while the block.size && POL prevote size
are fixed, so eventually we'll be able to "fully gossip" the block & POL.
TODO: cap the block.size at something reasonable.
Lemma 2: If a good node is at round R, neighboring good nodes will soon catch up to round R.
Lemma 3: If a node at (H,R) receives +2/3 prevotes for a block (or +2/3 for <nil>) at (H,R+1),
it will enter NewRound(H,R+1).
Lemma 4: Terminal conditions imply the existence of deterministic accountability, for
a synchronous (fixed-duration) protocol extension (judgement).
TODO: define terminal conditions (fork and non-decision).
TODO: define new assumptions for the synchronous judgement period.
+-------------------------------------+
v |(Wait til `CommmitTime+timeoutCommit`)
+-----------+ +-----+-----+
+----------> | Propose +--------------+ | NewHeight |
| +-----------+ | +-----------+
| | ^
|(Else, after timeoutPrecommit) v |
+-----+-----+ +-----------+ |
| Precommit | <------------------------+ Prevote | |
+-----+-----+ +-----------+ |
|(When +2/3 Precommits for block found) |
v |
+--------------------------------------------------------------------+
| Commit |
| |
| * Set CommitTime = now; |
| * Wait for block, then stage/save/commit block; |
+--------------------------------------------------------------------+
*/
package consensus
import (
"bytes"
"errors"
"fmt"
"sync"
"sync/atomic"
"time"
"github.com/tendermint/tendermint/account"
"github.com/tendermint/tendermint/binary"
bc "github.com/tendermint/tendermint/blockchain"
. "github.com/tendermint/tendermint/common"
. "github.com/tendermint/tendermint/consensus/types"
"github.com/tendermint/tendermint/events"
mempl "github.com/tendermint/tendermint/mempool"
sm "github.com/tendermint/tendermint/state"
"github.com/tendermint/tendermint/types"
)
var (
timeoutPropose = 3000 * time.Millisecond // Maximum duration of RoundStepPropose
timeoutPrevote0 = 1000 * time.Millisecond // After any +2/3 prevotes received, wait this long for stragglers.
timeoutPrevoteDelta = 0500 * time.Millisecond // timeoutPrevoteN is timeoutPrevote0 + timeoutPrevoteDelta*N
timeoutPrecommit0 = 1000 * time.Millisecond // After any +2/3 precommits received, wait this long for stragglers.
timeoutPrecommitDelta = 0500 * time.Millisecond // timeoutPrecommitN is timeoutPrecommit0 + timeoutPrecommitDelta*N
timeoutCommit = 2000 * time.Millisecond // After +2/3 commits received for committed block, wait this long for stragglers in the next height's RoundStepNewHeight.
)
var (
ErrInvalidProposalSignature = errors.New("Error invalid proposal signature")
ErrInvalidProposalPOLRound = errors.New("Error invalid proposal POL round")
)
//-----------------------------------------------------------------------------
// RoundStepType enum type
type RoundStepType uint8 // These must be numeric, ordered.
const (
RoundStepNewHeight = RoundStepType(0x01) // Wait til CommitTime + timeoutCommit
RoundStepNewRound = RoundStepType(0x02) // Setup new round and go to RoundStepPropose
RoundStepPropose = RoundStepType(0x03) // Did propose, gossip proposal
RoundStepPrevote = RoundStepType(0x04) // Did prevote, gossip prevotes
RoundStepPrevoteWait = RoundStepType(0x05) // Did receive any +2/3 prevotes, start timeout
RoundStepPrecommit = RoundStepType(0x06) // Did precommit, gossip precommits
RoundStepPrecommitWait = RoundStepType(0x07) // Did receive any +2/3 precommits, start timeout
RoundStepCommit = RoundStepType(0x08) // Entered commit state machine
// NOTE: RoundStepNewHeight acts as RoundStepCommitWait.
)
func (rs RoundStepType) String() string {
switch rs {
case RoundStepNewHeight:
return "RoundStepNewHeight"
case RoundStepNewRound:
return "RoundStepNewRound"
case RoundStepPropose:
return "RoundStepPropose"
case RoundStepPrevote:
return "RoundStepPrevote"
case RoundStepPrevoteWait:
return "RoundStepPrevoteWait"
case RoundStepPrecommit:
return "RoundStepPrecommit"
case RoundStepPrecommitWait:
return "RoundStepPrecommitWait"
case RoundStepCommit:
return "RoundStepCommit"
default:
panic(Fmt("Unknown RoundStep %X", rs))
}
}
//-----------------------------------------------------------------------------
// Immutable when returned from ConsensusState.GetRoundState()
type RoundState struct {
Height int // Height we are working on
Round int
Step RoundStepType
StartTime time.Time
CommitTime time.Time // Subjective time when +2/3 precommits for Block at Round were found
Validators *sm.ValidatorSet
Proposal *Proposal
ProposalBlock *types.Block
ProposalBlockParts *types.PartSet
LockedRound int
LockedBlock *types.Block
LockedBlockParts *types.PartSet
Votes *HeightVoteSet
LastCommit *VoteSet // Last precommits at Height-1
LastValidators *sm.ValidatorSet
}
func (rs *RoundState) String() string {
return rs.StringIndented("")
}
func (rs *RoundState) StringIndented(indent string) string {
return fmt.Sprintf(`RoundState{
%s H:%v R:%v S:%v
%s StartTime: %v
%s CommitTime: %v
%s Validators: %v
%s Proposal: %v
%s ProposalBlock: %v %v
%s LockedRound: %v
%s LockedBlock: %v %v
%s Votes: %v
%s LastCommit: %v
%s LastValidators: %v
%s}`,
indent, rs.Height, rs.Round, rs.Step,
indent, rs.StartTime,
indent, rs.CommitTime,
indent, rs.Validators.StringIndented(indent+" "),
indent, rs.Proposal,
indent, rs.ProposalBlockParts.StringShort(), rs.ProposalBlock.StringShort(),
indent, rs.LockedRound,
indent, rs.LockedBlockParts.StringShort(), rs.LockedBlock.StringShort(),
indent, rs.Votes.StringIndented(indent+" "),
indent, rs.LastCommit.StringShort(),
indent, rs.LastValidators.StringIndented(indent+" "),
indent)
}
func (rs *RoundState) StringShort() string {
return fmt.Sprintf(`RoundState{H:%v R:%v S:%v ST:%v}`,
rs.Height, rs.Round, rs.Step, rs.StartTime)
}
//-----------------------------------------------------------------------------
// Tracks consensus state across block heights and rounds.
type ConsensusState struct {
started uint32
stopped uint32
quit chan struct{}
blockStore *bc.BlockStore
mempoolReactor *mempl.MempoolReactor
privValidator *sm.PrivValidator
newStepCh chan *RoundState
mtx sync.Mutex
RoundState
state *sm.State // State until height-1.
stagedBlock *types.Block // Cache last staged block.
stagedState *sm.State // Cache result of staged block.
evsw events.Fireable
evc *events.EventCache // set in stageBlock and passed into state
}
func NewConsensusState(state *sm.State, blockStore *bc.BlockStore, mempoolReactor *mempl.MempoolReactor) *ConsensusState {
cs := &ConsensusState{
quit: make(chan struct{}),
blockStore: blockStore,
mempoolReactor: mempoolReactor,
newStepCh: make(chan *RoundState, 10),
}
cs.updateToState(state, true)
// Don't call scheduleRound0 yet.
// We do that upon Start().
cs.maybeRebond()
cs.reconstructLastCommit(state)
return cs
}
// Reconstruct LastCommit from SeenValidation, which we saved along with the block,
// (which happens even before saving the state)
func (cs *ConsensusState) reconstructLastCommit(state *sm.State) {
if state.LastBlockHeight == 0 {
return
}
lastPrecommits := NewVoteSet(state.LastBlockHeight, 0, types.VoteTypePrecommit, state.LastBondedValidators)
seenValidation := cs.blockStore.LoadSeenValidation(state.LastBlockHeight)
for idx, precommit := range seenValidation.Precommits {
added, _, err := lastPrecommits.AddByIndex(idx, precommit)
if !added || err != nil {
panic(Fmt("Failed to reconstruct LastCommit: %v", err))
}
}
if !lastPrecommits.HasTwoThirdsMajority() {
panic("Failed to reconstruct LastCommit: Does not have +2/3 maj")
}
cs.LastCommit = lastPrecommits
}
func (cs *ConsensusState) GetState() *sm.State {
cs.mtx.Lock()
defer cs.mtx.Unlock()
return cs.state.Copy()
}
func (cs *ConsensusState) GetRoundState() *RoundState {
cs.mtx.Lock()
defer cs.mtx.Unlock()
return cs.getRoundState()
}
func (cs *ConsensusState) getRoundState() *RoundState {
rs := cs.RoundState // copy
return &rs
}
func (cs *ConsensusState) NewStepCh() chan *RoundState {
return cs.newStepCh
}
func (cs *ConsensusState) Start() {
if atomic.CompareAndSwapUint32(&cs.started, 0, 1) {
log.Info("Starting ConsensusState")
cs.scheduleRound0(cs.Height)
}
}
// EnterNewRound(height, 0) at cs.StartTime.
func (cs *ConsensusState) scheduleRound0(height int) {
//log.Debug("scheduleRound0", "now", time.Now(), "startTime", cs.StartTime)
sleepDuration := cs.StartTime.Sub(time.Now())
go func() {
if 0 < sleepDuration {
time.Sleep(sleepDuration)
}
cs.EnterNewRound(height, 0)
}()
}
func (cs *ConsensusState) Stop() {
if atomic.CompareAndSwapUint32(&cs.stopped, 0, 1) {
log.Info("Stopping ConsensusState")
close(cs.quit)
}
}
func (cs *ConsensusState) IsStopped() bool {
return atomic.LoadUint32(&cs.stopped) == 1
}
// Updates ConsensusState and increments height to match that of state.
// The round becomes 0 and cs.Step becomes RoundStepNewHeight.
func (cs *ConsensusState) updateToState(state *sm.State, contiguous bool) {
// SANITY CHECK
if contiguous && 0 < cs.Height && cs.Height != state.LastBlockHeight {
panic(Fmt("updateToState() expected state height of %v but found %v",
cs.Height, state.LastBlockHeight))
}
// END SANITY CHECK
// Reset fields based on state.
validators := state.BondedValidators
height := state.LastBlockHeight + 1 // next desired block height
lastPrecommits := (*VoteSet)(nil)
if contiguous && cs.Votes != nil {
if !cs.Votes.Precommits(cs.Round).HasTwoThirdsMajority() {
panic("updateToState(state, true) called but last Precommit round didn't have +2/3")
}
lastPrecommits = cs.Votes.Precommits(cs.Round)
}
// RoundState fields
cs.Height = height
cs.Round = 0
cs.Step = RoundStepNewHeight
if cs.CommitTime.IsZero() {
// "Now" makes it easier to sync up dev nodes.
// We add timeoutCommit to allow transactions
// to be gathered for the first block.
// And alternative solution that relies on clocks:
// cs.StartTime = state.LastBlockTime.Add(timeoutCommit)
cs.StartTime = time.Now().Add(timeoutCommit)
} else {
cs.StartTime = cs.CommitTime.Add(timeoutCommit)
}
cs.CommitTime = time.Time{}
cs.Validators = validators
cs.Proposal = nil
cs.ProposalBlock = nil
cs.ProposalBlockParts = nil
cs.LockedRound = 0
cs.LockedBlock = nil
cs.LockedBlockParts = nil
cs.Votes = NewHeightVoteSet(height, validators)
cs.LastCommit = lastPrecommits
cs.LastValidators = state.LastBondedValidators
cs.state = state
cs.stagedBlock = nil
cs.stagedState = nil
// Finally, broadcast RoundState
cs.newStepCh <- cs.getRoundState()
}
// If we're unbonded, broadcast RebondTx.
func (cs *ConsensusState) maybeRebond() {
if cs.privValidator == nil || !cs.state.UnbondingValidators.HasAddress(cs.privValidator.Address) {
return
}
rebondTx := &types.RebondTx{
Address: cs.privValidator.Address,
Height: cs.Height,
}
err := cs.privValidator.SignRebondTx(cs.state.ChainID, rebondTx)
if err == nil {
err := cs.mempoolReactor.BroadcastTx(rebondTx)
if err != nil {
log.Error("Failed to broadcast RebondTx",
"height", cs.Height, "round", cs.Round, "tx", rebondTx, "error", err)
} else {
log.Info("Signed and broadcast RebondTx",
"height", cs.Height, "round", cs.Round, "tx", rebondTx)
}
} else {
log.Warn("Error signing RebondTx", "height", cs.Height, "round", cs.Round, "tx", rebondTx, "error", err)
}
}
func (cs *ConsensusState) SetPrivValidator(priv *sm.PrivValidator) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
cs.privValidator = priv
}
//-----------------------------------------------------------------------------
// Enter: +2/3 precommits for nil at (height,round-1)
// Enter: `timeoutPrecommits` after any +2/3 precommits from (height,round-1)
// Enter: `startTime = commitTime+timeoutCommit` from NewHeight(height)
// NOTE: cs.StartTime was already set for height.
func (cs *ConsensusState) EnterNewRound(height int, round int) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
if cs.Height != height || round < cs.Round || (cs.Round == round && cs.Step != RoundStepNewHeight) {
log.Debug(Fmt("EnterNewRound(%v/%v): Invalid args. Current step: %v/%v/%v", height, round, cs.Height, cs.Round, cs.Step))
return
}
if now := time.Now(); cs.StartTime.After(now) {
log.Warn("Need to set a buffer and log.Warn() here for sanity.", "startTime", cs.StartTime, "now", now)
}
// Increment validators if necessary
validators := cs.Validators
if cs.Round < round {
validators = validators.Copy()
validators.IncrementAccum(round - cs.Round)
}
// Setup new round
cs.Round = round
cs.Step = RoundStepNewRound
cs.Validators = validators
cs.Proposal = nil
cs.ProposalBlock = nil
cs.ProposalBlockParts = nil
cs.Votes.SetRound(round + 1) // also track next round (round+1) to allow round-skipping
// Immediately go to EnterPropose.
go cs.EnterPropose(height, round)
}
// Enter: from NewRound(height,round).
func (cs *ConsensusState) EnterPropose(height int, round int) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
if cs.Height != height || round < cs.Round || (cs.Round == round && RoundStepPropose <= cs.Step) {
log.Debug(Fmt("EnterPropose(%v/%v): Invalid args. Current step: %v/%v/%v", height, round, cs.Height, cs.Round, cs.Step))
return
}
defer func() {
// Done EnterPropose:
cs.Round = round
cs.Step = RoundStepPropose
cs.newStepCh <- cs.getRoundState()
// If we already have the proposal + POL, then goto Prevote
if cs.isProposalComplete() {
go cs.EnterPrevote(height, cs.Round)
}
}()
// This step times out after `timeoutPropose`
go func() {
time.Sleep(timeoutPropose)
cs.EnterPrevote(height, round)
}()
// Nothing more to do if we're not a validator
if cs.privValidator == nil {
return
}
if !bytes.Equal(cs.Validators.Proposer().Address, cs.privValidator.Address) {
log.Debug("EnterPropose: Not our turn to propose", "proposer", cs.Validators.Proposer().Address, "privValidator", cs.privValidator)
} else {
log.Debug("EnterPropose: Our turn to propose", "proposer", cs.Validators.Proposer().Address, "privValidator", cs.privValidator)
cs.decideProposal(height, round)
}
}
// Decides on the next proposal and sets them onto cs.Proposal*
func (cs *ConsensusState) decideProposal(height int, round int) {
var block *types.Block
var blockParts *types.PartSet
// Decide on block
if cs.LockedBlock != nil {
// If we're locked onto a block, just choose that.
block, blockParts = cs.LockedBlock, cs.LockedBlockParts
} else {
// Create a new proposal block from state/txs from the mempool.
block, blockParts = cs.createProposalBlock()
}
// Make proposal
proposal := NewProposal(height, round, blockParts.Header(), cs.Votes.POLRound())
err := cs.privValidator.SignProposal(cs.state.ChainID, proposal)
if err == nil {
log.Info("Signed and set proposal", "height", height, "round", round, "proposal", proposal)
log.Debug(Fmt("Signed and set proposal block: %v", block))
// Set fields
cs.Proposal = proposal
cs.ProposalBlock = block
cs.ProposalBlockParts = blockParts
} else {
log.Warn("EnterPropose: Error signing proposal", "height", height, "round", round, "error", err)
}
}
// Returns true if the proposal block is complete &&
// (if POLRound was proposed, we have +2/3 prevotes from there).
func (cs *ConsensusState) isProposalComplete() bool {
if cs.Proposal == nil || cs.ProposalBlock == nil {
return false
}
if cs.Proposal.POLRound < 0 {
return true
} else {
return cs.Votes.Prevotes(cs.Proposal.POLRound).HasTwoThirdsMajority()
}
}
// Create the next block to propose and return it.
// NOTE: make it side-effect free for clarity.
func (cs *ConsensusState) createProposalBlock() (block *types.Block, blockParts *types.PartSet) {
var validation *types.Validation
if cs.Height == 1 {
// We're creating a proposal for the first block.
// The validation is empty, but not nil.
validation = &types.Validation{}
} else if cs.LastCommit.HasTwoThirdsMajority() {
// Make the validation from LastCommit
validation = cs.LastCommit.MakeValidation()
} else {
// This shouldn't happen.
log.Error("EnterPropose: Cannot propose anything: No validation for the previous block.")
return
}
txs := cs.mempoolReactor.Mempool.GetProposalTxs()
block = &types.Block{
Header: &types.Header{
ChainID: cs.state.ChainID,
Height: cs.Height,
Time: time.Now(),
Fees: 0, // TODO fees
NumTxs: len(txs),
LastBlockHash: cs.state.LastBlockHash,
LastBlockParts: cs.state.LastBlockParts,
StateHash: nil, // Will set afterwards.
},
LastValidation: validation,
Data: &types.Data{
Txs: txs,
},
}
// Set the block.Header.StateHash.
err := cs.state.ComputeBlockStateHash(block)
if err != nil {
log.Error("EnterPropose: Error setting state hash", "error", err)
return
}
blockParts = block.MakePartSet()
return block, blockParts
}
// Enter: `timeoutPropose` after entering Propose.
// Enter: proposal block and POL is ready.
// Enter: any +2/3 prevotes for future round.
// Prevote for LockedBlock if we're locked, or ProposalBlock if valid.
// Otherwise vote nil.
func (cs *ConsensusState) EnterPrevote(height int, round int) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
if cs.Height != height || round < cs.Round || (cs.Round == round && RoundStepPrevote <= cs.Step) {
log.Debug(Fmt("EnterPrevote(%v/%v): Invalid args. Current step: %v/%v/%v", height, round, cs.Height, cs.Round, cs.Step))
return
}
// Sign and broadcast vote as necessary
cs.doPrevote(height, round)
// Done EnterPrevote:
cs.Round = round
cs.Step = RoundStepPrevote
cs.newStepCh <- cs.getRoundState()
/* This isn't necessary because addVote() does it for us.
if cs.Votes.Prevotes(round).HasTwoThirdsAny() {
go cs.EnterPrevoteWait(height, round)
}*/
}
func (cs *ConsensusState) doPrevote(height int, round int) {
// If a block is locked, prevote that.
if cs.LockedBlock != nil {
log.Debug("EnterPrevote: Block was locked")
cs.signAddVote(types.VoteTypePrevote, cs.LockedBlock.Hash(), cs.LockedBlockParts.Header())
return
}
// If ProposalBlock is nil, prevote nil.
if cs.ProposalBlock == nil {
log.Warn("EnterPrevote: ProposalBlock is nil")
cs.signAddVote(types.VoteTypePrevote, nil, types.PartSetHeader{})
return
}
// Try staging cs.ProposalBlock
err := cs.stageBlock(cs.ProposalBlock, cs.ProposalBlockParts)
if err != nil {
// ProposalBlock is invalid, prevote nil.
log.Warn("EnterPrevote: ProposalBlock is invalid", "error", err)
cs.signAddVote(types.VoteTypePrevote, nil, types.PartSetHeader{})
return
}
// Prevote cs.ProposalBlock
cs.signAddVote(types.VoteTypePrevote, cs.ProposalBlock.Hash(), cs.ProposalBlockParts.Header())
return
}
// Enter: any +2/3 prevotes at next round.
func (cs *ConsensusState) EnterPrevoteWait(height int, round int) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
if cs.Height != height || round < cs.Round || (cs.Round == round && RoundStepPrevoteWait <= cs.Step) {
log.Debug(Fmt("EnterPrevoteWait(%v/%v): Invalid args. Current step: %v/%v/%v", height, round, cs.Height, cs.Round, cs.Step))
return
}
if !cs.Votes.Prevotes(round).HasTwoThirdsAny() {
panic(Fmt("EnterPrevoteWait(%v/%v), but Prevotes does not have any +2/3 votes", height, round))
}
// Done EnterPrevoteWait:
cs.Round = round
cs.Step = RoundStepPrevoteWait
cs.newStepCh <- cs.getRoundState()
// After `timeoutPrevote0+timeoutPrevoteDelta*round`, EnterPrecommit()
go func() {
time.Sleep(timeoutPrevote0 + timeoutPrevote0*time.Duration(round))
cs.EnterPrecommit(height, round)
}()
}
// Enter: +2/3 precomits for block or nil.
// Enter: `timeoutPrevote` after any +2/3 prevotes.
// Enter: any +2/3 precommits for next round.
// Lock & precommit the ProposalBlock if we have enough prevotes for it,
// else, unlock an existing lock and precommit nil if +2/3 of prevotes were nil,
// else, precommit locked block or nil otherwise.
func (cs *ConsensusState) EnterPrecommit(height int, round int) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
if cs.Height != height || round < cs.Round || (cs.Round == round && RoundStepPrecommit <= cs.Step) {
log.Debug(Fmt("EnterPrecommit(%v/%v): Invalid args. Current step: %v/%v/%v", height, round, cs.Height, cs.Round, cs.Step))
return
}
defer func() {
// Done EnterPrecommit:
cs.Round = round
cs.Step = RoundStepPrecommit
cs.newStepCh <- cs.getRoundState()
/* This isn't necessary because addVote() does it for us.
if cs.Votes.Precommits(round).HasTwoThirdsAny() {
go cs.EnterPrecommitWait(height, round)
}*/
}()
hash, partsHeader, ok := cs.Votes.Prevotes(round).TwoThirdsMajority()
// If we don't have two thirds of prevotes, just precommit locked block or nil
if !ok {
if cs.LockedBlock != nil {
log.Info("EnterPrecommit: No +2/3 prevotes during EnterPrecommit. Precommitting lock.")
cs.signAddVote(types.VoteTypePrecommit, cs.LockedBlock.Hash(), cs.LockedBlockParts.Header())
} else {
log.Info("EnterPrecommit: No +2/3 prevotes during EnterPrecommit. Precommitting nil.")
cs.signAddVote(types.VoteTypePrecommit, nil, types.PartSetHeader{})
}
return
}
// +2/3 prevoted nil. Unlock and precommit nil.
if len(hash) == 0 {
if cs.LockedBlock == nil {
log.Info("EnterPrecommit: +2/3 prevoted for nil.")
} else {
log.Info("EnterPrecommit: +2/3 prevoted for nil. Unlocking")
cs.LockedRound = 0
cs.LockedBlock = nil
cs.LockedBlockParts = nil
}
cs.signAddVote(types.VoteTypePrecommit, nil, types.PartSetHeader{})
return
}
// At this point, +2/3 prevoted for a particular block.
// If +2/3 prevoted for already locked block, precommit it.
if cs.LockedBlock.HashesTo(hash) {
log.Info("EnterPrecommit: +2/3 prevoted locked block.")
cs.signAddVote(types.VoteTypePrecommit, hash, partsHeader)
return
}
// If +2/3 prevoted for proposal block, stage and precommit it
if cs.ProposalBlock.HashesTo(hash) {
log.Info("EnterPrecommit: +2/3 prevoted proposal block.")
// Validate the block.
if err := cs.stageBlock(cs.ProposalBlock, cs.ProposalBlockParts); err != nil {
panic(Fmt("EnterPrecommit: +2/3 prevoted for an invalid block: %v", err))
}
cs.LockedRound = round
cs.LockedBlock = cs.ProposalBlock
cs.LockedBlockParts = cs.ProposalBlockParts
cs.signAddVote(types.VoteTypePrecommit, hash, partsHeader)
return
}
// Otherwise, we need to fetch the +2/3 prevoted block.
// Unlock and precommit nil.
// The +2/3 prevotes for this round is the POL for our unlock.
if cs.Votes.POLRound() < round {
panic(Fmt("This POLRound shold be %v but got %", round, cs.Votes.POLRound()))
}
cs.LockedRound = 0
cs.LockedBlock = nil
cs.LockedBlockParts = nil
if !cs.ProposalBlockParts.HasHeader(partsHeader) {
cs.ProposalBlock = nil
cs.ProposalBlockParts = types.NewPartSetFromHeader(partsHeader)
}
cs.signAddVote(types.VoteTypePrecommit, nil, types.PartSetHeader{})
return
}
// Enter: any +2/3 precommits for next round.
func (cs *ConsensusState) EnterPrecommitWait(height int, round int) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
if cs.Height != height || round < cs.Round || (cs.Round == round && RoundStepPrecommitWait <= cs.Step) {
log.Debug(Fmt("EnterPrecommitWait(%v/%v): Invalid args. Current step: %v/%v/%v", height, round, cs.Height, cs.Round, cs.Step))
return
}
if !cs.Votes.Precommits(round).HasTwoThirdsAny() {
panic(Fmt("EnterPrecommitWait(%v/%v), but Precommits does not have any +2/3 votes", height, round))
}
// Done EnterPrecommitWait:
cs.Round = round
cs.Step = RoundStepPrecommitWait
cs.newStepCh <- cs.getRoundState()
// After `timeoutPrecommit0+timeoutPrecommitDelta*round`, EnterNewRound()
go func() {
time.Sleep(timeoutPrecommit0 + timeoutPrecommitDelta*time.Duration(round))
// If we have +2/3 of precommits for a particular block (or nil),
// we already entered commit (or the next round).
// So just try to transition to the next round,
// which is what we'd do otherwise.
cs.EnterNewRound(height, round+1)
}()
}
// Enter: +2/3 precommits for block
func (cs *ConsensusState) EnterCommit(height int) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
if cs.Height != height || RoundStepCommit <= cs.Step {
log.Debug(Fmt("EnterCommit(%v): Invalid args. Current step: %v/%v/%v", height, cs.Height, cs.Round, cs.Step))
return
}
defer func() {
// Done Entercommit:
// keep ca.Round the same, it points to the right Precommits set.
cs.Step = RoundStepCommit
cs.newStepCh <- cs.getRoundState()
// Maybe finalize immediately.
cs.tryFinalizeCommit(height)
}()
// SANITY CHECK
hash, partsHeader, ok := cs.Votes.Precommits(cs.Round).TwoThirdsMajority()
if !ok {
panic("RunActionCommit() expects +2/3 precommits")
}
// END SANITY CHECK
// The Locked* fields no longer matter.
// Move them over to ProposalBlock if they match the commit hash,
// otherwise they can now be cleared.
if cs.LockedBlock.HashesTo(hash) {
cs.ProposalBlock = cs.LockedBlock
cs.ProposalBlockParts = cs.LockedBlockParts
cs.LockedRound = 0
cs.LockedBlock = nil
cs.LockedBlockParts = nil
} else {
cs.LockedRound = 0
cs.LockedBlock = nil
cs.LockedBlockParts = nil
}
// If we don't have the block being committed, set up to get it.
if !cs.ProposalBlock.HashesTo(hash) {
if !cs.ProposalBlockParts.HasHeader(partsHeader) {
// We're getting the wrong block.
// Set up ProposalBlockParts and keep waiting.
cs.ProposalBlock = nil
cs.ProposalBlockParts = types.NewPartSetFromHeader(partsHeader)
} else {
// We just need to keep waiting.
}
}
}
// If we have the block AND +2/3 commits for it, finalize.
func (cs *ConsensusState) tryFinalizeCommit(height int) {
// SANITY CHECK
if cs.Height != height {
panic(Fmt("tryFinalizeCommit() cs.Height: %v vs height: %v", cs.Height, height))
}
// END SANITY CHECK
hash, _, ok := cs.Votes.Precommits(cs.Round).TwoThirdsMajority()
if !ok || len(hash) == 0 {
return // There was no +2/3 majority, or +2/3 was for <nil>.
}
if !cs.ProposalBlock.HashesTo(hash) {
return // We don't have the commit block.
}
go cs.FinalizeCommit(height)
}
// Increment height and goto RoundStepNewHeight
func (cs *ConsensusState) FinalizeCommit(height int) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
if cs.Height != height || cs.Step != RoundStepCommit {
log.Debug(Fmt("FinalizeCommit(%v): Invalid args. Current step: %v/%v/%v", height, cs.Height, cs.Round, cs.Step))
return
}
hash, header, ok := cs.Votes.Precommits(cs.Round).TwoThirdsMajority()
// SANITY CHECK
if !ok {
panic(Fmt("Cannot FinalizeCommit, commit does not have two thirds majority"))
}
if !cs.ProposalBlockParts.HasHeader(header) {
panic(Fmt("Expected ProposalBlockParts header to be commit header"))
}
if !cs.ProposalBlock.HashesTo(hash) {
panic(Fmt("Cannot FinalizeCommit, ProposalBlock does not hash to commit hash"))
}
if err := cs.stageBlock(cs.ProposalBlock, cs.ProposalBlockParts); err != nil {
panic(Fmt("+2/3 committed an invalid block: %v", err))
}
// END SANITY CHECK
log.Debug(Fmt("Finalizing commit of block: %v", cs.ProposalBlock))
// We have the block, so stage/save/commit-vote.
cs.saveBlock(cs.ProposalBlock, cs.ProposalBlockParts, cs.Votes.Precommits(cs.Round))
// Increment height.
cs.updateToState(cs.stagedState, true)
// cs.StartTime is already set.
// Schedule Round0 to start soon.
go cs.scheduleRound0(height + 1)
// If we're unbonded, broadcast RebondTx.
cs.maybeRebond()
// By here,
// * cs.Height has been increment to height+1
// * cs.Step is now RoundStepNewHeight
// * cs.StartTime is set to when we will start round0.
return
}
//-----------------------------------------------------------------------------
func (cs *ConsensusState) SetProposal(proposal *Proposal) error {
cs.mtx.Lock()
defer cs.mtx.Unlock()
// Already have one
if cs.Proposal != nil {
return nil
}
// Does not apply
if proposal.Height != cs.Height || proposal.Round != cs.Round {
return nil
}
// We don't care about the proposal if we're already in RoundStepCommit.
if RoundStepCommit <= cs.Step {
return nil
}
// Verify POLRound, which must be -1 or between 0 and proposal.Round exclusive.
if proposal.POLRound != -1 &&
(proposal.POLRound < 0 || proposal.Round <= proposal.POLRound) {
return ErrInvalidProposalPOLRound
}
// Verify signature
if !cs.Validators.Proposer().PubKey.VerifyBytes(account.SignBytes(cs.state.ChainID, proposal), proposal.Signature) {
return ErrInvalidProposalSignature
}
cs.Proposal = proposal
cs.ProposalBlockParts = types.NewPartSetFromHeader(proposal.BlockPartsHeader)
return nil
}
// NOTE: block is not necessarily valid.
func (cs *ConsensusState) AddProposalBlockPart(height int, part *types.Part) (added bool, err error) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
// Blocks might be reused, so round mismatch is OK
if cs.Height != height {
return false, nil
}
// We're not expecting a block part.
if cs.ProposalBlockParts == nil {
return false, nil // TODO: bad peer? Return error?
}
added, err = cs.ProposalBlockParts.AddPart(part)
if err != nil {
return added, err
}
if added && cs.ProposalBlockParts.IsComplete() {
// Added and completed!
var n int64
var err error
cs.ProposalBlock = binary.ReadBinary(&types.Block{}, cs.ProposalBlockParts.GetReader(), &n, &err).(*types.Block)
log.Debug("Received complete proposal", "hash", cs.ProposalBlock.Hash())
if cs.Step == RoundStepPropose && cs.isProposalComplete() {
// Move onto the next step
go cs.EnterPrevote(height, cs.Round)
} else if cs.Step == RoundStepCommit {
// If we're waiting on the proposal block...
cs.tryFinalizeCommit(height)
}
return true, err
}
return added, nil
}
func (cs *ConsensusState) AddVote(address []byte, vote *types.Vote, peerKey string) (added bool, index int, err error) {
cs.mtx.Lock()
defer cs.mtx.Unlock()
return cs.addVote(address, vote, peerKey)
}
//-----------------------------------------------------------------------------
func (cs *ConsensusState) addVote(address []byte, vote *types.Vote, peerKey string) (added bool, index int, err error) {
// A precommit for the previous height?
if vote.Height+1 == cs.Height && vote.Type == types.VoteTypePrecommit {
added, index, err = cs.LastCommit.AddByAddress(address, vote)
if added {
log.Debug(Fmt("Added to lastPrecommits: %v", cs.LastCommit.StringShort()))
}
return
}
// A prevote/precommit for this height?
if vote.Height == cs.Height {
height := cs.Height
added, index, err = cs.Votes.AddByAddress(address, vote, peerKey)
if added {
switch vote.Type {
case types.VoteTypePrevote:
prevotes := cs.Votes.Prevotes(vote.Round)
log.Debug(Fmt("Added to prevotes: %v", prevotes.StringShort()))
// First, unlock if prevotes is a valid POL.
// >> lockRound < POLRound <= unlockOrChangeLockRound (see spec)
// NOTE: If (lockRound < POLRound) but !(POLRound <= unlockOrChangeLockRound),
// we'll still EnterNewRound(H,vote.R) and EnterPrecommit(H,vote.R) to process it
// there.
if (cs.LockedBlock != nil) && (cs.LockedRound < vote.Round) && (vote.Round <= cs.Round) {
hash, _, ok := prevotes.TwoThirdsMajority()
if ok && !cs.LockedBlock.HashesTo(hash) {
log.Info("Unlocking because of POL.", "lockedRound", cs.LockedRound, "POLRound", vote.Round)
cs.LockedRound = 0
cs.LockedBlock = nil
cs.LockedBlockParts = nil
}
}
if cs.Round <= vote.Round && prevotes.HasTwoThirdsAny() {
// Round-skip over to PrevoteWait or goto Precommit.
go func() {
if cs.Round < vote.Round {
cs.EnterNewRound(height, vote.Round)
}
if prevotes.HasTwoThirdsMajority() {
cs.EnterPrecommit(height, vote.Round)
} else {
cs.EnterPrevote(height, vote.Round)
cs.EnterPrevoteWait(height, vote.Round)
}
}()
} else if cs.Proposal != nil && 0 <= cs.Proposal.POLRound && cs.Proposal.POLRound == vote.Round {
// If the proposal is now complete, enter prevote of cs.Round.
if cs.isProposalComplete() {
go cs.EnterPrevote(height, cs.Round)
}
}
case types.VoteTypePrecommit:
precommits := cs.Votes.Precommits(vote.Round)
log.Debug(Fmt("Added to precommit: %v", precommits.StringShort()))
if cs.Round <= vote.Round && precommits.HasTwoThirdsAny() {
go func() {
hash, _, ok := precommits.TwoThirdsMajority()
if ok && len(hash) == 0 {
cs.EnterNewRound(height, vote.Round+1)
return
} else if cs.Round < vote.Round {
cs.EnterNewRound(height, vote.Round)
}
if ok {
cs.EnterCommit(height)
} else {
cs.EnterPrecommit(height, vote.Round)
cs.EnterPrecommitWait(height, vote.Round)
}
}()
}
default:
panic(Fmt("Unexpected vote type %X", vote.Type)) // Should not happen.
}
}
return
}
// Height mismatch, bad peer? TODO
return
}
func (cs *ConsensusState) stageBlock(block *types.Block, blockParts *types.PartSet) error {
if block == nil {
panic("Cannot stage nil block")
}
// Already staged?
blockHash := block.Hash()
if cs.stagedBlock != nil && len(blockHash) != 0 && bytes.Equal(cs.stagedBlock.Hash(), blockHash) {
return nil
}
// Create a copy of the state for staging
stateCopy := cs.state.Copy()
// reset the event cache and pass it into the state
cs.evc = events.NewEventCache(cs.evsw)
stateCopy.SetFireable(cs.evc)
// Commit block onto the copied state.
// NOTE: Basic validation is done in state.AppendBlock().
err := sm.ExecBlock(stateCopy, block, blockParts.Header())
if err != nil {
return err
} else {
cs.stagedBlock = block
cs.stagedState = stateCopy
return nil
}
}
func (cs *ConsensusState) signAddVote(type_ byte, hash []byte, header types.PartSetHeader) *types.Vote {
if cs.privValidator == nil || !cs.Validators.HasAddress(cs.privValidator.Address) {
return nil
}
vote := &types.Vote{
Height: cs.Height,
Round: cs.Round,
Type: type_,
BlockHash: hash,
BlockParts: header,
}
err := cs.privValidator.SignVote(cs.state.ChainID, vote)
if err == nil {
_, _, err := cs.addVote(cs.privValidator.Address, vote, "")
log.Info("Signed and added vote", "height", cs.Height, "round", cs.Round, "vote", vote, "error", err)
return vote
} else {
log.Warn("Error signing vote", "height", cs.Height, "round", cs.Round, "vote", vote, "error", err)
return nil
}
}
// Save Block, save the +2/3 Commits we've seen
func (cs *ConsensusState) saveBlock(block *types.Block, blockParts *types.PartSet, commits *VoteSet) {
// The proposal must be valid.
if err := cs.stageBlock(block, blockParts); err != nil {
panic(Fmt("saveBlock() an invalid block: %v", err))
}
// Save to blockStore.
if cs.blockStore.Height() < block.Height {
seenValidation := commits.MakeValidation()
cs.blockStore.SaveBlock(block, blockParts, seenValidation)
}
// Save the state.
cs.stagedState.Save()
// Update mempool.
cs.mempoolReactor.Mempool.ResetForBlockAndState(block, cs.stagedState)
// Fire off event
go func(block *types.Block) {
cs.evsw.FireEvent(types.EventStringNewBlock(), block)
cs.evc.Flush()
}(block)
}
// implements events.Eventable
func (cs *ConsensusState) SetFireable(evsw events.Fireable) {
cs.evsw = evsw
}