simplify pluginwatcher closing

pkg/kubelet/util/pluginwatcher/plugin_watcher.go

@@ -39,10 +39,10 @@ import (
 type Watcher struct {
 	path           string
 	deprecatedPath string
-	stopCh         chan interface{}
+	stopCh         chan struct{}
+	stopped        chan struct{}
 	fs             utilfs.Filesystem
 	fsWatcher      *fsnotify.Watcher
-	wg             sync.WaitGroup
 
 	mutex       sync.Mutex
 	handlers    map[string]PluginHandler
@@ -88,7 +88,8 @@ func (w *Watcher) getHandler(pluginType string) (PluginHandler, bool) {
 // Start watches for the creation of plugin sockets at the path
 func (w *Watcher) Start() error {
 	klog.V(2).Infof("Plugin Watcher Start at %s", w.path)
-	w.stopCh = make(chan interface{})
+	w.stopCh = make(chan struct{})
+	w.stopped = make(chan struct{})
 
 	// Creating the directory to be watched if it doesn't exist yet,
 	// and walks through the directory to discover the existing plugins.
@@ -104,22 +105,20 @@ func (w *Watcher) Start() error {
 
 	// Traverse plugin dir and add filesystem watchers before starting the plugin processing goroutine.
 	if err := w.traversePluginDir(w.path); err != nil {
-		w.Stop()
+		w.fsWatcher.Close()
 		return fmt.Errorf("failed to traverse plugin socket path %q, err: %v", w.path, err)
 	}
 
 	// Traverse deprecated plugin dir, if specified.
 	if len(w.deprecatedPath) != 0 {
 		if err := w.traversePluginDir(w.deprecatedPath); err != nil {
-			w.Stop()
+			w.fsWatcher.Close()
 			return fmt.Errorf("failed to traverse deprecated plugin socket path %q, err: %v", w.deprecatedPath, err)
 		}
 	}
 
-	w.wg.Add(1)
-	go func(fsWatcher *fsnotify.Watcher) {
-		defer w.wg.Done()
-
+	go func() {
+		defer close(w.stopped)
 		for {
 			select {
 			case event := <-fsWatcher.Events:
@@ -135,17 +134,15 @@ func (w *Watcher) Start() error {
 						klog.Errorf("error %v when handling delete event: %s", err, event)
 					}
 				}
-				continue
 			case err := <-fsWatcher.Errors:
 				if err != nil {
 					klog.Errorf("fsWatcher received error: %v", err)
 				}
-				continue
 			case <-w.stopCh:
 				return
 			}
 		}
-	}(fsWatcher)
+	}()
 
 	return nil
 }
@@ -154,18 +151,9 @@ func (w *Watcher) Start() error {
 func (w *Watcher) Stop() error {
 	close(w.stopCh)
 
-	c := make(chan struct{})
-	var once sync.Once
-	closeFunc := func() { close(c) }
-	go func() {
-		defer once.Do(closeFunc)
-		w.wg.Wait()
-	}()
-
 	select {
-	case <-c:
+	case <-w.stopped:
 	case <-time.After(11 * time.Second):
-		once.Do(closeFunc)
 		return fmt.Errorf("timeout on stopping watcher")
 	}