Avoid tripping the race detector

We need to set a flag so that the sendMsgs goroutine can return errors
if the stream is down. However, using a bool for this was tripping the
race detector. To avoid this, we can use atomic load/store instead.

Author: johningve

cmd/protoc-gen-gorums/dev/ordering.go

@@ -73,7 +73,7 @@ type orderedNodeStream struct {
 	gorumsClient ordering.GorumsClient
 	gorumsStream ordering.Gorums_NodeStreamClient
 	streamMut    sync.RWMutex
-	streamBroken bool
+	streamBroken uint32
 }
 
 func (s *orderedNodeStream) connectOrderedStream(ctx context.Context, conn *grpc.ClientConn) error {
@@ -97,7 +97,7 @@ func (s *orderedNodeStream) sendMsgs(ctx context.Context) {
 		case req = <-s.sendQ:
 		}
 		// return error if stream is broken
-		if s.streamBroken {
+		if atomic.LoadUint32(&s.streamBroken) == 1 {
 			err := status.Errorf(codes.Unavailable, "stream is down")
 			s.putResult(req.metadata.MessageID, &orderingResult{nid: s.node.ID(), reply: nil, err: err})
 			continue
@@ -109,7 +109,7 @@ func (s *orderedNodeStream) sendMsgs(ctx context.Context) {
 			s.streamMut.RUnlock()
 			continue
 		}
-		s.streamBroken = true
+		atomic.StoreUint32(&s.streamBroken, 1)
 		s.streamMut.RUnlock()
 		s.node.setLastErr(err)
 		// return the error
@@ -123,7 +123,7 @@ func (s *orderedNodeStream) recvMsgs(ctx context.Context) {
 		s.streamMut.RLock()
 		err := s.gorumsStream.RecvMsg(resp)
 		if err != nil {
-			s.streamBroken = true
+			atomic.StoreUint32(&s.streamBroken, 1)
 			s.streamMut.RUnlock()
 			s.node.setLastErr(err)
 			// attempt to reconnect
@@ -151,7 +151,7 @@ func (s *orderedNodeStream) reconnectStream(ctx context.Context) {
 		var err error
 		s.gorumsStream, err = s.gorumsClient.NodeStream(ctx)
 		if err == nil {
-			s.streamBroken = false
+			atomic.StoreUint32(&s.streamBroken, 0)
 			return
 		}
 		s.node.setLastErr(err)