catch RuntimeErrors when the service is no longer available

rqt_controller_manager/rqt_controller_manager/controller_manager.py

@@ -172,16 +172,22 @@ def _list_controllers(self):
         @rtype [str]
         """
         # Add loaded controllers first
-        controllers = list_controllers(self._node, self._cm_name).controller
-
-        # Append potential controller configs found in the node's parameters
-        for name in _get_parameter_controller_names(self._node, self._cm_name):
-            add_ctrl = all(name != ctrl.name for ctrl in controllers)
-            if add_ctrl:
-                type_str = _get_controller_type(self._node, self._cm_name, name)
-                uninit_ctrl = ControllerState(name=name, type=type_str)
-                controllers.append(uninit_ctrl)
-        return controllers
+        try:
+            controllers = list_controllers(
+                self._node, self._cm_name, 2.0 / self._cm_update_freq
+            ).controller
+
+            # Append potential controller configs found in the node's parameters
+            for name in _get_parameter_controller_names(self._node, self._cm_name):
+                add_ctrl = all(name != ctrl.name for ctrl in controllers)
+                if add_ctrl:
+                    type_str = _get_controller_type(self._node, self._cm_name, name)
+                    uninit_ctrl = ControllerState(name=name, type=type_str)
+                    controllers.append(uninit_ctrl)
+            return controllers
+        except RuntimeError as e:
+            print(e)
+            return []
 
     def _show_controllers(self):
         table_view = self._widget.table_view