Send a commit whenever we can create a PreparedCertificate (ethereum#596)

Author: Asa Oines

.circleci/config.yml

@@ -69,7 +69,7 @@ jobs:
           command: |
             set -euo pipefail
             export CELO_MONOREPO_DIR="$PWD"
-            git clone --depth 1 https://github.com/celo-org/celo-monorepo.git ${CELO_MONOREPO_DIR} -b asaj/parent-signatures
+            git clone --depth 1 https://github.com/celo-org/celo-monorepo.git ${CELO_MONOREPO_DIR} -b master
             yarn install || yarn install
             # separate build to avoid ENOMEM in CI :(
             yarn build --scope @celo/utils

consensus/istanbul/core/commit.go

@@ -136,11 +136,13 @@ func (c *core) handleCommit(msg *istanbul.Message) error {
 			logger.Trace("Got a quorum of commits", "tag", "stateTransition", "commits", c.current.Commits)
 			c.commit()
 		} else if c.current.GetPrepareOrCommitSize() >= minQuorumSize && c.state.Cmp(StatePrepared) < 0 {
-			logger.Trace("Got enough prepares and commits to generate a PreparedCertificate")
 			if err := c.current.CreateAndSetPreparedCertificate(minQuorumSize); err != nil {
 				logger.Error("Failed to create and set preprared certificate", "err", err)
 				return err
 			}
+			logger.Trace("Got quorum prepares or commits", "tag", "stateTransition", "commits", c.current.Commits, "prepares", c.current.Prepares)
+			c.setState(StatePrepared)
+			c.sendCommit()
 		}
 	}
 

consensus/istanbul/core/prepare.go

@@ -146,6 +146,7 @@ func (c *core) handlePrepare(msg *istanbul.Message) error {
 	// TODO(joshua): Remove state comparisons (or change the cmp function)
 	if (preparesAndCommits >= minQuorumSize) && c.state.Cmp(StatePrepared) < 0 {
 		if err := c.current.CreateAndSetPreparedCertificate(minQuorumSize); err != nil {
+			logger.Error("Failed to create and set preprared certificate", "err", err)
 			return err
 		}
 		logger.Trace("Got quorum prepares or commits", "tag", "stateTransition", "commits", c.current.Commits, "prepares", c.current.Prepares)

consensus/istanbul/core/roundstate.go

@@ -63,7 +63,15 @@ func (s *roundState) GetPrepareOrCommitSize() int {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
-	return s.getPrepareOrCommitSize()
+	result := s.Prepares.Size() + s.Commits.Size()
+
+	// find duplicate one
+	for _, m := range s.Prepares.Values() {
+		if s.Commits.Get(m.Address) != nil {
+			result--
+		}
+	}
+	return result
 }
 
 func (s *roundState) Subject() *istanbul.Subject {
@@ -143,51 +151,36 @@ func (s *roundState) Sequence() *big.Int {
 	return s.sequence
 }
 
-func (s *roundState) SetPreparedCertificate(preparedCertificate istanbul.PreparedCertificate) {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	s.preparedCertificate = preparedCertificate
-}
-
 func (s *roundState) CreateAndSetPreparedCertificate(quorumSize int) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
-	prepareOrCommitSize := s.getPrepareOrCommitSize()
-	if prepareOrCommitSize >= quorumSize {
-		messages := make([]istanbul.Message, prepareOrCommitSize)
-		i := 0
-		for _, message := range s.Prepares.Values() {
-			messages[i] = *message
-			i++
+	messages := make([]istanbul.Message, quorumSize)
+	i := 0
+	for _, message := range s.Prepares.Values() {
+		if i == quorumSize {
+			break
 		}
-		for _, message := range s.Commits.Values() {
-			if s.Prepares.Get(message.Address) == nil {
-				messages[i] = *message
-				i++
-			}
+		messages[i] = *message
+		i++
+	}
+	for _, message := range s.Commits.Values() {
+		if i == quorumSize {
+			break
 		}
-		s.preparedCertificate = istanbul.PreparedCertificate{
-			Proposal:                s.Preprepare.Proposal,
-			PrepareOrCommitMessages: messages,
+		if s.Prepares.Get(message.Address) == nil {
+			messages[i] = *message
+			i++
 		}
-		return nil
-	} else {
+	}
+	if i != quorumSize {
 		return errFailedCreatePreparedCertificate
 	}
-}
-
-func (s *roundState) getPrepareOrCommitSize() int {
-	result := s.Prepares.Size() + s.Commits.Size()
-
-	// find duplicate one
-	for _, m := range s.Prepares.Values() {
-		if s.Commits.Get(m.Address) != nil {
-			result--
-		}
+	s.preparedCertificate = istanbul.PreparedCertificate{
+		Proposal:                s.Preprepare.Proposal,
+		PrepareOrCommitMessages: messages,
 	}
-	return result
+	return nil
 }
 
 // The DecodeRLP method should read one value from the given