Fix: EventManager error on unregister of receiver

service/Event.go

@@ -71,14 +71,17 @@ func (em *EventManager) RegisterReceiver(filterEventType int64) *EventReceiver {
 	fmt.Printf("Registered receiver for %d\n", er.FilterEventType)
 	em.receiverRegListMutex.Lock()
 	em.receiverRegisterList[er] = true
+	er.isRegistered = true
 	em.receiverRegListMutex.Unlock()
 
 	return er
 }
 
 func (em *EventManager) UnregisterReceiver(receiver *EventReceiver) {
+	if !receiver.isRegistered { return }
 	em.receiverDelListMutex.Lock()
 	em.receiverDeleteList[receiver] = true
+	receiver.isRegistered = false
 	em.receiverDelListMutex.Unlock()
 }
 
@@ -88,6 +91,27 @@ loop:
 	for {
 		select {
 		case evToDispatch := <-em.eventQueue:
+			// delete receivers marked for deletion (only unregister function is allowed to put data into this map)
+			em.receiverDelListMutex.Lock()
+			for delReceiver := range em.receiverDeleteList {
+				delete(em.registeredReceivers, delReceiver)
+				close(delReceiver.EventQueue)
+				delReceiver.Cancel()
+			}
+			//Replace the delete list with a new one and let the GC take care of the old
+			em.receiverDeleteList = make(map[*EventReceiver]bool)
+			em.receiverDelListMutex.Unlock()
+
+			//add newly registered receivers
+			em.receiverRegListMutex.Lock()
+			for addReceiver := range em.receiverRegisterList {
+				em.registeredReceivers[addReceiver] = true
+			}
+			//Replace the register list with a new one and let the GC take care of the old
+			em.receiverRegisterList = make(map[*EventReceiver]bool)
+			em.receiverRegListMutex.Unlock()
+
+
 			// distribute to registered receiver
 			// Note: no mutex on em.registeredReceivers needed, only accessed in this method
 			for receiver := range em.registeredReceivers {
@@ -104,24 +128,6 @@ loop:
 				}
 			}
 
-			// delete receivers marked for deletion (only unregister function is allowed to put data into this map)
-			em.receiverDelListMutex.Lock()
-			for delReceiver := range em.receiverDeleteList {
-				delete(em.registeredReceivers, delReceiver)
-				close(delReceiver.EventQueue)
-			}
-			//Replace the delete list with a new one and let the GC take care of the old
-			em.receiverDeleteList = make(map[*EventReceiver]bool)
-			em.receiverDelListMutex.Unlock()
-
-			//add newly registered receivers
-			em.receiverRegListMutex.Lock()
-			for addReceiver := range em.receiverRegisterList {
-				em.registeredReceivers[addReceiver] = true
-			}
-			//Replace the register list with a new one and let the GC take care of the old
-			em.receiverRegisterList = make(map[*EventReceiver]bool)
-			em.receiverRegListMutex.Unlock()
 
 
 		case <-em.ctx.Done():
@@ -136,6 +142,7 @@ loop:
 }
 
 type EventReceiver struct {
+	isRegistered bool
 	Ctx             context.Context
 	Cancel          context.CancelFunc
 	EventQueue      chan *pb.Event

service/triggerAction.go

@@ -0,0 +1 @@
+package service