def __setattr__(self, name, value): if name == 'thread': if value is None: if self.id in _task_threads: del _task_threads[self.id] else: _task_threads[self.id] = value else: DatabaseObject.__setattr__(self, name, value) if name == 'state' and value: Event(volume_id=self.volume_id, type=TASKS_UPDATED)