fix: restart BL states when device config updated

Author: d-perl

bec_lib/bec_lib/bl_states.py

@@ -286,6 +286,7 @@ def start(self) -> None:
             self.update_device_signal_info()
         except Exception as exc:
             self._handle_state_exception(exc)
+            self.started = False
             return
 
         msg = self.connector.get(MessageEndpoints.device_readback(self.device_obj.root.name))

bec_server/bec_server/scan_server/beamline_state_manager.py

@@ -6,6 +6,7 @@
 from bec_lib.alarm_handler import Alarms
 from bec_lib.devicemanager import DeviceManagerBase
 from bec_lib.endpoints import MessageEndpoints
+from bec_lib.logger import bec_logger
 from bec_lib.messages import ErrorInfo
 from bec_lib.redis_connector import RedisConnector
 
@@ -22,6 +23,7 @@ def __init__(self, connector: RedisConnector, device_manager: DeviceManagerBase)
             cb=self._handle_state_update,
             from_start=True,
         )
+        self.connector.register(MessageEndpoints.device_config_update(), cb=self.restart_all)
 
     def _handle_state_update(self, msg_dict: dict, **_kwargs) -> None:
 
@@ -30,13 +32,18 @@ def _handle_state_update(self, msg_dict: dict, **_kwargs) -> None:
             self.update_states(msg)
         except Exception as exc:
             content = traceback.format_exc()
+            bec_logger.logger.error(content)
             info = ErrorInfo(
                 exception_type=type(exc).__name__,
                 error_message=content,
                 compact_error_message="Error updating beamline states.",
             )
             self.connector.raise_alarm(severity=Alarms.WARNING, info=info)
 
+    def restart_all(self, *_):
+        for state in self._states.values():
+            state.restart()
+
     def update_states(self, msg: messages.AvailableBeamlineStatesMessage) -> None:
         """
         Update the beamline states based on the received update message.

bec_server/tests/tests_scan_server/test_beamline_state_manager.py

@@ -39,17 +39,22 @@ def restart(self):
     return FakeState
 
 
-def test_state_manager_fetches_states(dm_with_devices):
+def test_state_manager_fetches_states(dm_with_devices, fake_bl_states):
     """
     Test that the BeamlineStateManager fetches all available beamline states on initialization.
     """
 
     connector = mock.MagicMock()
     state_manager = BeamlineStateManager(connector, device_manager=dm_with_devices)
-    connector.register.assert_called_once_with(
-        MessageEndpoints.available_beamline_states(),
-        cb=state_manager._handle_state_update,
-        from_start=True,
+    connector.register.assert_has_calls(
+        [
+            mock.call(
+                MessageEndpoints.available_beamline_states(),
+                cb=state_manager._handle_state_update,
+                from_start=True,
+            ),
+            mock.call(MessageEndpoints.device_config_update(), cb=state_manager.restart_all),
+        ]
     )
 
 
@@ -125,3 +130,17 @@ def test_state_manager_updates_states(state_manager, connected_connector, fake_b
 
     assert len(state_manager._states) == 1
     assert "State2" in state_manager._states
+
+
+@pytest.mark.timeout(5)
+def test_states_restarted_when_device_config_updated(
+    state_manager, connected_connector, fake_bl_states
+):
+    state_mock = mock.MagicMock()
+    state_manager._states["test"] = state_mock
+    connected_connector.send(
+        MessageEndpoints.device_config_update(), messages.DeviceConfigMessage(action="reload")
+    )
+
+    while state_mock.restart.call_count == 0:
+        time.sleep(0.1)