Protect object map from concurrent access

default_handler.go

@@ -38,12 +38,29 @@ type defaultHandler struct {
 	defaultIntf map[string]*exportedIntf
 }
 
-func (h *defaultHandler) PathExists(path ObjectPath) bool {
-	_, ok := h.objects[path]
-	return ok
+func (h *defaultHandler) GetExportedObject(path ObjectPath) (*exportedObj, bool) {
+	h.RLock()
+	defer h.RUnlock()
+	obj, ok := h.objects[path]
+	return obj, ok
+}
+
+// GetOrAddExportedObject returns an exportedObj for an specific ObjectPath
+// A new exportedObj is created if none existed for ObjectPath
+func (h *defaultHandler) GetOrAddExportedObject(path ObjectPath) *exportedObj {
+	h.RLock()
+	defer h.RUnlock()
+	obj, ok := h.objects[path]
+	if !ok {
+		obj = newExportedObject()
+		h.objects[path] = obj
+	}
+	return obj
 }
 
 func (h *defaultHandler) introspectPath(path ObjectPath) string {
+	h.RLock()
+	defer h.RUnlock()
 	subpath := make(map[string]struct{})
 	var xml bytes.Buffer
 	xml.WriteString("<node>")
@@ -65,8 +82,8 @@ func (h *defaultHandler) introspectPath(path ObjectPath) string {
 }
 
 func (h *defaultHandler) LookupObject(path ObjectPath) (ServerObject, bool) {
-	h.RLock()
-	defer h.RUnlock()
+	h.Lock()
+	defer h.Unlock()
 	object, ok := h.objects[path]
 	if ok {
 		return object, ok

export.go

@@ -363,8 +363,7 @@ func (conn *Conn) exportMethodTable(methods map[string]interface{}, path ObjectP
 }
 
 func (conn *Conn) unexport(h *defaultHandler, path ObjectPath, iface string) error {
-	if h.PathExists(path) {
-		obj := h.objects[path]
+	if obj, ok := h.GetExportedObject(path); ok {
 		obj.DeleteInterface(iface)
 		if len(obj.interfaces) == 0 {
 			h.DeleteObject(path)
@@ -391,21 +390,18 @@ func (conn *Conn) export(methods map[string]reflect.Value, path ObjectPath, ifac
 		return conn.unexport(h, path, iface)
 	}
 
-	// If this is the first handler for this path, make a new map to hold all
-	// handlers for this path.
-	if !h.PathExists(path) {
-		h.AddObject(path, newExportedObject())
-	}
-
+	// Get all Methods that should be exported
+	// Get all Methods that should be exported
 	exportedMethods := make(map[string]Method)
 	for name, method := range methods {
 		exportedMethods[name] = exportedMethod{method}
 	}
 
+	// Get a handler for the path, either an existing or a new fresh one
+	obj := h.GetOrAddExportedObject(path)
+
 	// Finally, save this handler
-	obj := h.objects[path]
 	obj.AddInterface(iface, newExportedIntf(exportedMethods, includeSubtree))
-
 	return nil
 }