Merge pull request #15 from huskar-t/fix/advise

fix: advise

opcgroup.go

@@ -274,7 +274,7 @@ type DataChangeCallBackData struct {
 
 // RegisterDataChange Register to receive data change events
 func (g *OPCGroup) RegisterDataChange(ch chan *DataChangeCallBackData) error {
-	err := g.advice()
+	err := g.advise()
 	if err != nil {
 		return err
 	}
@@ -284,7 +284,7 @@ func (g *OPCGroup) RegisterDataChange(ch chan *DataChangeCallBackData) error {
 
 // RegisterReadComplete Register to receive read complete events
 func (g *OPCGroup) RegisterReadComplete(ch chan *ReadCompleteCallBackData) error {
-	err := g.advice()
+	err := g.advise()
 	if err != nil {
 		return err
 	}
@@ -294,7 +294,7 @@ func (g *OPCGroup) RegisterReadComplete(ch chan *ReadCompleteCallBackData) error
 
 // RegisterWriteComplete Register to receive write complete events
 func (g *OPCGroup) RegisterWriteComplete(ch chan *WriteCompleteCallBackData) error {
-	err := g.advice()
+	err := g.advise()
 	if err != nil {
 		return err
 	}
@@ -304,7 +304,7 @@ func (g *OPCGroup) RegisterWriteComplete(ch chan *WriteCompleteCallBackData) err
 
 // RegisterCancelComplete Register to receive cancel complete events
 func (g *OPCGroup) RegisterCancelComplete(ch chan *CancelCompleteCallBackData) error {
-	err := g.advice()
+	err := g.advise()
 	if err != nil {
 		return err
 	}
@@ -337,7 +337,7 @@ type CancelCompleteCallBackData struct {
 	GroupHandle uint32
 }
 
-func (g *OPCGroup) advice() (err error) {
+func (g *OPCGroup) advise() (err error) {
 	g.callbackLock.Lock()
 	defer g.callbackLock.Unlock()
 	if g.event != nil {

opcserver.go

@@ -78,37 +78,6 @@ func Connect(progID, node string) (opcServer *OPCServer, err error) {
 		location:      location,
 	}
 	opcServer.groups = NewOPCGroups(opcServer)
-
-	var iUnknownContainer *com.IUnknown
-	err = iUnknownServer.QueryInterface(&com.IID_IConnectionPointContainer, unsafe.Pointer(&iUnknownContainer))
-	if err != nil {
-		return opcServer, nil
-	}
-	defer func() {
-		if err != nil {
-			iUnknownContainer.Release()
-		}
-	}()
-	container := &com.IConnectionPointContainer{IUnknown: iUnknownContainer}
-	point, err := container.FindConnectionPoint(&IID_IOPCShutdown)
-	if err != nil {
-		return nil, NewOPCWrapperError("container find connect point", err)
-	}
-	defer func() {
-		if err != nil {
-			point.Release()
-		}
-	}()
-	event := NewShutdownEventReceiver()
-	cookie, err := point.Advise((*com.IUnknown)(unsafe.Pointer(event)))
-	if err != nil {
-		return nil, NewOPCWrapperError("point advice", err)
-	}
-
-	opcServer.container = container
-	opcServer.point = point
-	opcServer.event = event
-	opcServer.cookie = cookie
 	return opcServer, nil
 }
 
@@ -476,6 +445,41 @@ func (s *OPCServer) errors(errs []int32) []error {
 
 // RegisterServerShutDown register server shut down event
 func (s *OPCServer) RegisterServerShutDown(ch chan string) error {
+	if s.event == nil {
+		var err error
+		var iUnknownContainer *com.IUnknown
+		var point *com.IConnectionPoint
+		var cookie uint32
+
+		err = s.iServer.IUnknown.QueryInterface(&com.IID_IConnectionPointContainer, unsafe.Pointer(&iUnknownContainer))
+		if err != nil {
+			return NewOPCWrapperError("query interface IConnectionPointContainer", err)
+		}
+		defer func() {
+			if err != nil {
+				iUnknownContainer.Release()
+			}
+		}()
+		container := &com.IConnectionPointContainer{IUnknown: iUnknownContainer}
+		point, err = container.FindConnectionPoint(&IID_IOPCShutdown)
+		if err != nil {
+			return NewOPCWrapperError("container find connect point", err)
+		}
+		defer func() {
+			if err != nil {
+				point.Release()
+			}
+		}()
+		event := NewShutdownEventReceiver()
+		cookie, err = point.Advise((*com.IUnknown)(unsafe.Pointer(event)))
+		if err != nil {
+			return NewOPCWrapperError("point advise", err)
+		}
+		s.container = container
+		s.point = point
+		s.event = event
+		s.cookie = cookie
+	}
 	s.event.AddReceiver(ch)
 	return nil
 }