Block messages when a Resend Request is active

in_session.go

@@ -208,8 +208,10 @@ func (state inSession) handleResendRequest(session *session, msg *Message) (next
 	}
 
 	if err := state.resendMessages(session, int(beginSeqNo), endSeqNo, *msg); err != nil {
+		session.isResendRequestActive = false
 		return handleStateError(session, err)
 	}
+	session.isResendRequestActive = false
 
 	if err := session.checkTargetTooLow(msg); err != nil {
 		return state
@@ -291,7 +293,7 @@ func (state inSession) processReject(session *session, msg *Message, rej Message
 			nextState = currentState
 		default:
 			var err error
-			if nextState, err = session.doTargetTooHigh(TypedError); err != nil {
+			if nextState, err = session.doTargetTooHigh(TypedError, true); err != nil {
 				return handleStateError(session, err)
 			}
 		}

in_session_test.go

@@ -373,6 +373,26 @@ func (s *InSessionTestSuite) TestFIXMsgInResendRequestDoNotSendApp() {
 	s.State(inSession{})
 }
 
+func (s *InSessionTestSuite) TestIsResendRequestActive() {
+	s.MockApp.On("FromAdmin").Return(nil)
+	s.MockApp.On("ToApp").Return(nil)
+	s.MockApp.On("ToAdmin")
+	s.sendResendRequest(5, 10, false)
+	s.True(s.isResendRequestActive)
+
+	nos := s.NewOrderSingle()
+	err := s.session.send(nos)
+
+	s.Error(err)
+	s.EqualError(err, "cannot send message while resend request is active")
+	s.fixMsgIn(s.session, s.ResendRequest(5))
+	s.False(s.isResendRequestActive)
+
+	err = s.session.send(nos)
+
+	s.NoError(err)
+}
+
 func (s *InSessionTestSuite) TestFIXMsgInTargetTooLow() {
 	s.IncrNextTargetMsgSeqNum()
 

logon_state.go

@@ -46,7 +46,7 @@ func (s logonState) FixMsgIn(session *session, msg *Message) (nextState sessionS
 
 		case targetTooHigh:
 			var tooHighErr error
-			if nextState, tooHighErr = session.doTargetTooHigh(err); tooHighErr != nil {
+			if nextState, tooHighErr = session.doTargetTooHigh(err, false); tooHighErr != nil {
 				return shutdownWithReason(session, msg, false, tooHighErr.Error())
 			}
 

resend_state.go

@@ -48,7 +48,7 @@ func (s resendState) FixMsgIn(session *session, msg *Message) (nextState session
 	}
 
 	if s.currentResendRangeEnd != 0 && s.currentResendRangeEnd < session.store.NextTargetMsgSeqNum() {
-		nextResendState, err := session.sendResendRequest(session.store.NextTargetMsgSeqNum(), s.resendRangeEnd)
+		nextResendState, err := session.sendResendRequest(session.store.NextTargetMsgSeqNum(), s.resendRangeEnd, false)
 		if err != nil {
 			return handleStateError(session, err)
 		}
@@ -64,7 +64,7 @@ func (s resendState) FixMsgIn(session *session, msg *Message) (nextState session
 	}
 
 	if bool(gapFillFlag) && s.currentResendRangeEnd != 0 && s.currentResendRangeEnd == session.store.NextTargetMsgSeqNum() {
-		nextResendState, err := session.sendResendRequest(session.store.NextTargetMsgSeqNum(), s.resendRangeEnd)
+		nextResendState, err := session.sendResendRequest(session.store.NextTargetMsgSeqNum(), s.resendRangeEnd, false)
 		if err != nil {
 			return handleStateError(session, err)
 		}

session.go

@@ -52,6 +52,8 @@ type session struct {
 	sentReset  bool
 	stopOnce   sync.Once
 
+	isResendRequestActive bool
+
 	targetDefaultApplVerID string
 
 	admin chan interface{}
@@ -295,6 +297,10 @@ func (s *session) notifyMessageOut() {
 
 // send will validate, persist, queue the message. If the session is logged on, send all messages in the queue.
 func (s *session) send(msg *Message) error {
+	if err := s.isResendRequestBlocking(msg); err != nil {
+		return err
+	}
+
 	return s.sendInReplyTo(msg, nil)
 }
 func (s *session) sendInReplyTo(msg *Message, inReplyTo *Message) error {
@@ -316,6 +322,20 @@ func (s *session) sendInReplyTo(msg *Message, inReplyTo *Message) error {
 	return nil
 }
 
+func (s *session) isResendRequestBlocking(msg *Message) error {
+	msgType, err := msg.Header.GetBytes(tagMsgType)
+	if err != nil {
+		return err
+	}
+
+	if s.isResendRequestActive && !bytes.Equal(msgType, msgTypeResendRequest) {
+		s.log.OnEvent("Message blocked: resend request in progress")
+		return errors.New("cannot send message while resend request is active")
+	}
+
+	return nil
+}
+
 // dropAndReset will drop the send queue and reset the message store.
 func (s *session) dropAndReset() error {
 	s.sendMutex.Lock()
@@ -443,12 +463,12 @@ func (s *session) sendBytes(msg []byte, blockUntilSent bool) bool {
 	}
 }
 
-func (s *session) doTargetTooHigh(reject targetTooHigh) (nextState resendState, err error) {
+func (s *session) doTargetTooHigh(reject targetTooHigh, isReject bool) (nextState resendState, err error) {
 	s.log.OnEventf("MsgSeqNum too high, expecting %v but received %v", reject.ExpectedTarget, reject.ReceivedTarget)
-	return s.sendResendRequest(reject.ExpectedTarget, reject.ReceivedTarget-1)
+	return s.sendResendRequest(reject.ExpectedTarget, reject.ReceivedTarget-1, isReject)
 }
 
-func (s *session) sendResendRequest(beginSeq, endSeq int) (nextState resendState, err error) {
+func (s *session) sendResendRequest(beginSeq, endSeq int, isReject bool) (nextState resendState, err error) {
 	nextState.resendRangeEnd = endSeq
 
 	resend := NewMessage()
@@ -477,6 +497,9 @@ func (s *session) sendResendRequest(beginSeq, endSeq int) (nextState resendState
 		return
 	}
 	s.log.OnEventf("Sent ResendRequest FROM: %v TO: %v", beginSeq, endSeqNo)
+	if !isReject {
+		s.isResendRequestActive = true
+	}
 
 	return
 }