fix freeze during server shutdown

internal/clientman/clientman.go

@@ -198,13 +198,22 @@ outer:
 	}
 
 	go func() {
-		for range cm.clientClose {
+		for {
+			select {
+			case _, ok := <-cm.clientClose:
+				if !ok {
+					return
+				}
+
+			case <-cm.pathMan.ClientClose():
+			}
 		}
 	}()
 
 	for c := range cm.clients {
 		c.Close()
 	}
+
 	cm.wg.Wait()
 
 	close(cm.clientClose)

internal/path/path.go

@@ -287,7 +287,6 @@ outer:
 
 			delete(pa.clients, req.Client)
 			pa.clientsWg.Done()
-
 			close(req.Res)
 
 		case <-pa.terminate:
@@ -419,7 +418,6 @@ func (pa *Path) exhaustChannels() {
 				}
 
 				pa.clientsWg.Done()
-
 				close(req.Res)
 			}
 		}