import threading from openstack.observer import OpenStackObserver from openstack.event_manager import EventListener class Backend: def run(self): # start the openstack observer observer = OpenStackObserver() observer_thread = threading.Thread(target=observer.run) observer_thread.start() # start event listene event_manager = EventListener(wake_up=observer.wake_up) event_manager_thread = threading.Thread(target=event_manager.run) event_manager_thread.start()