Handle force-stop with leftover camera threads

When a forced stop finds camera threads still running, also clear failed camera state, buffered frames and timestamps (under the frame lock), and reset expected cameras to 0. Add a critical log warning that background camera threads may still be active and emit all_stopped so the GUI can leave the running state; warn that an application restart may be required. This prevents stale state from blocking future starts while making the risk visible in logs.

Author: C-Achard

dlclivegui/services/multi_camera_controller.py

@@ -264,6 +264,20 @@ def stop(self, wait: bool = True) -> None:
 
             if still_running:
                 self._started_cameras.clear()
+                self._failed_cameras.clear()
+                with self._frame_lock:
+                    self._frames.clear()
+                    self._timestamps.clear()
+                self._expected_cameras = 0
+
+                LOGGER.critical(
+                    "Force stop failed for camera threads: %s."
+                    "Sending all_stopped to leave GUI in running state,"
+                    "but background camera threads may still be active and interfere with future camera starts."
+                    "Application restart may be required.",
+                    still_running,
+                )
+                self.all_stopped.emit()
                 return
 
         self._started_cameras.clear()