Merge pull request #531 from shipa988/multi-dynamic-session-stop-deadlock

Multi dynamic session stop deadlock

Author: ackleymi

session.go

@@ -35,6 +35,7 @@ type session struct {
 	stateTimer *internal.EventTimer
 	peerTimer  *internal.EventTimer
 	sentReset  bool
+	stopOnce   sync.Once
 
 	targetDefaultApplVerID string
 
@@ -76,7 +77,10 @@ func (s *session) connect(msgIn <-chan fixIn, msgOut chan<- []byte) error {
 type stopReq struct{}
 
 func (s *session) stop() {
-	s.admin <- stopReq{}
+	//stop once
+	s.stopOnce.Do(func() {
+		s.admin <- stopReq{}
+	})
 }
 
 type waitChan <-chan interface{}