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comment cleanup

This commit is contained in:
Jae Kwon 2015-06-25 12:52:16 -07:00
parent 44216ab481
commit 32811c3f86
2 changed files with 35 additions and 20 deletions
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2
consensus/reactor.go
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@ -353,7 +353,7 @@ OUTER_LOOP:
}
// If the peer is on a previous height, help catch up.
if 0 < prs.Height && prs.Height < rs.Height {
if (0 < prs.Height) && (prs.Height < rs.Height) {
//log.Debug("Data catchup", "height", rs.Height, "peerHeight", prs.Height, "peerProposalBlockParts", prs.ProposalBlockParts)
if index, ok := prs.ProposalBlockParts.Not().PickRandom(); ok {
// Ensure that the peer's PartSetHeader is correct

53
consensus/state.go
View File

@ -1,31 +1,35 @@
/*
Consensus State Machine Overview:
Consensus State Machine Overview:
NewHeight, NewRound, Propose, Prevote, Precommit represent state machine steps. (aka RoundStep).
NewHeight, NewRound, Propose, Prevote, Precommit represent state machine steps. (aka RoundStep).
To "prevote/precommit" something means to broadcast a prevote/precommit vote for something.
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)
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.
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.
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).
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.
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
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)
@ -89,6 +93,13 @@
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`)
@ -1019,7 +1030,11 @@ func (cs *ConsensusState) addVote(address []byte, vote *types.Vote, peerKey stri
prevotes := cs.Votes.Prevotes(vote.Round)
log.Debug(Fmt("Added to prevotes: %v", prevotes.StringShort()))
// First, unlock if prevotes is a valid POL.
if cs.LockedBlock != nil && cs.LockedRound < vote.Round {
// >> 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)