From 7ad6d5bc0454179285ff5543e77757020b901d68 Mon Sep 17 00:00:00 2001
From: yiminc <yiminc@users.noreply.github.com>
Date: Thu, 7 Dec 2017 09:54:00 -0800
Subject: [PATCH] fix buffered events bug (#449)

---
 service/history/mutableStateBuilder.go       | 31 ++++++++++++++++----
 service/history/timerQueueProcessor2_test.go |  3 +-
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/service/history/mutableStateBuilder.go b/service/history/mutableStateBuilder.go
index a6df450006a..4e6369c682b 100644
--- a/service/history/mutableStateBuilder.go
+++ b/service/history/mutableStateBuilder.go
@@ -235,6 +235,7 @@ func (e *mutableStateBuilder) CloseUpdateSession() (*mutableStateSessionUpdates,
 	e.updateRequestCancelInfos = []*persistence.RequestCancelInfo{}
 	e.deleteRequestCancelInfo = nil
 	e.continueAsNew = nil
+	e.clearBufferedEvents = false
 	if e.updateBufferedEvents != nil {
 		e.bufferedEvents = append(e.bufferedEvents, e.updateBufferedEvents)
 		e.updateBufferedEvents = nil
@@ -328,19 +329,39 @@ func (e *mutableStateBuilder) isStickyTaskListEnabled() bool {
 
 func (e *mutableStateBuilder) createNewHistoryEvent(eventType workflow.EventType) *workflow.HistoryEvent {
 	eventID := e.executionInfo.NextEventID
-	if e.HasInFlightDecisionTask() &&
-		eventType != workflow.EventTypeDecisionTaskCompleted &&
-		eventType != workflow.EventTypeDecisionTaskFailed &&
-		eventType != workflow.EventTypeDecisionTaskTimedOut {
+	if e.shouldBufferEvent(eventType) {
 		eventID = bufferedEventID
 	} else {
-		// only increase NextEventID if there is no in-flight decision task
+		// only increase NextEventID if event is not buffered
 		e.executionInfo.NextEventID++
 	}
 
 	return e.createNewHistoryEventWithTimestamp(eventID, eventType, time.Now().UnixNano())
 }
 
+func (e *mutableStateBuilder) shouldBufferEvent(eventType workflow.EventType) bool {
+	if !e.HasInFlightDecisionTask() {
+		// do not buffer event if there is no in-flight decision
+		return false
+	}
+
+	switch eventType {
+	case workflow.EventTypeDecisionTaskCompleted,
+		workflow.EventTypeDecisionTaskFailed,
+		workflow.EventTypeDecisionTaskTimedOut,
+		workflow.EventTypeWorkflowExecutionCompleted,
+		workflow.EventTypeWorkflowExecutionFailed,
+		workflow.EventTypeWorkflowExecutionTimedOut,
+		workflow.EventTypeWorkflowExecutionTerminated,
+		workflow.EventTypeWorkflowExecutionContinuedAsNew,
+		workflow.EventTypeWorkflowExecutionCanceled:
+		// do not buffer event if it is any type of close decision or close workflow
+		return false
+	}
+
+	return true
+}
+
 func (e *mutableStateBuilder) createNewHistoryEventWithTimestamp(eventID int64, eventType workflow.EventType,
 	timestamp int64) *workflow.HistoryEvent {
 	ts := common.Int64Ptr(timestamp)
diff --git a/service/history/timerQueueProcessor2_test.go b/service/history/timerQueueProcessor2_test.go
index afe8f20a495..d1e0a11de7b 100644
--- a/service/history/timerQueueProcessor2_test.go
+++ b/service/history/timerQueueProcessor2_test.go
@@ -227,9 +227,8 @@ func (s *timerQueueProcessor2Suite) TestWorkflowTimeout() {
 	s.mockMetadataMgr.On("GetDomain", mock.Anything).Return(
 		&persistence.GetDomainResponse{Config: &persistence.DomainConfig{Retention: 1}}, nil).Once()
 	s.mockExecutionMgr.On("CompleteTimerTask", mock.Anything).Return(nil).Once()
+	s.mockHistoryMgr.On("AppendHistoryEvents", mock.Anything).Return(nil).Once()
 	s.mockExecutionMgr.On("UpdateWorkflowExecution", mock.Anything).Return(nil).Run(func(arguments mock.Arguments) {
-		request := arguments.Get(0).(*persistence.UpdateWorkflowExecutionRequest)
-		s.NotNil(request.NewBufferedEvents)
 		// Done.
 		waitCh <- struct{}{}
 	}).Once()