better code for deleting the listener

extensions/websocket/ws/manager.go

@@ -58,6 +58,7 @@ type SocketManager struct {
 	sockets                  *xsync.MapOf[string, *xsync.MapOf[string, SocketConnection]]
 	idToRoom                 *xsync.MapOf[string, string]
 	listeners                []chan SocketEvent
+	listenersQueuedForDelete map[chan SocketEvent]bool
 	goroutinesRunning        atomic.Int32
 	opts                     *opts.ExtensionOpts
 	lock                     sync.Mutex
@@ -129,6 +130,7 @@ func NewSocketManager(opts *opts.ExtensionOpts) *SocketManager {
 	return &SocketManager{
 		sockets:                  xsync.NewMapOf[string, *xsync.MapOf[string, SocketConnection]](),
 		idToRoom:                 xsync.NewMapOf[string, string](),
+		listenersQueuedForDelete: make(map[chan SocketEvent]bool),
 		opts:                     opts,
 		goroutinesRunning:        atomic.Int32{},
 	}
@@ -186,14 +188,7 @@ func (manager *SocketManager) Listen(listener chan SocketEvent) {
 }
 
 func (manager *SocketManager) RemoveListener(listener chan SocketEvent) {
-	for i, l := range manager.listeners {
+	manager.listenersQueuedForDelete[listener] = true
-		if l == listener {
-			slog.Debug("ws-extension: removed listener from manager")
-			manager.listeners = append(manager.listeners[:i], manager.listeners[i+1:]...)
-			slog.Debug("ws-extension: total listeners", slog.Int("count", len(manager.listeners)))
-			return
-		}
-	}
 }
 
 func (manager *SocketManager) dispatch(event SocketEvent) {
@@ -208,9 +203,27 @@ func (manager *SocketManager) dispatch(event SocketEvent) {
 			}
 		}
 	}()
+
+	if len(manager.listenersQueuedForDelete) > 0 {
+		newListener := make([]chan SocketEvent, 0)
 		for _, listener := range manager.listeners {
-		listener <- event
+			if _, ok := manager.listenersQueuedForDelete[listener]; !ok {
+				newListener = append(newListener, listener)
 			}
+		}
+		manager.listeners = newListener
+	}
+
+	wg := sync.WaitGroup{}
+	for _, listener := range manager.listeners {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			listener <- event
+		}()
+	}
+
+	wg.Wait()
 	done <- struct{}{}
 }