Fix race condition in consensus.State code (#673) (#690)

* Repro in e2e tests * Change something in the code * Fix race condition in `SwitchToConsensus` * Revert "Repro in e2e tests" This reverts commit 4f441f8ebac8f245d5a641c25ccdfa3b382ca063. * RAII lock (cherry picked from commit 6a96eca67fb810aa823e9de4da41cc8028637a65) Co-authored-by: Sergio Mena <[email protected]>
skip-mev · Apr 11, 2023 · e0b2aae · e0b2aae
1 parent 2eb6994
commit e0b2aae
Showing 1 changed file with 12 additions and 7 deletions.
diff --git a/consensus/reactor.go b/consensus/reactor.go
@@ -107,14 +107,19 @@ func (conR *Reactor) OnStop() {
 func (conR *Reactor) SwitchToConsensus(state sm.State, skipWAL bool) {
 	conR.Logger.Info("SwitchToConsensus")
 
-	// We have no votes, so reconstruct LastCommit from SeenCommit.
-	if state.LastBlockHeight > 0 {
-		conR.conS.reconstructLastCommit(state)
-	}
+	func() {
+		// We need to lock, as we are not entering consensus state from State's `handleMsg` or `handleTimeout`
+		conR.conS.mtx.Lock()
+		defer conR.conS.mtx.Unlock()
+		// We have no votes, so reconstruct LastCommit from SeenCommit
+		if state.LastBlockHeight > 0 {
+			conR.conS.reconstructLastCommit(state)
+		}
 
-	// NOTE: The line below causes broadcastNewRoundStepRoutine() to broadcast a
-	// NewRoundStepMessage.
-	conR.conS.updateToState(state)
+		// NOTE: The line below causes broadcastNewRoundStepRoutine() to broadcast a
+		// NewRoundStepMessage.
+		conR.conS.updateToState(state)
+	}()
 
 	conR.mtx.Lock()
 	conR.waitSync = false