def __init__(self, event_callback, unsubscribe_callback, period=0.5):
QtCore.QThread.__init__(self)
self.listeners = CaselessDict()
self.inverse_listeners = {}
self.event_callback = event_callback
self.unsubscribe_callback = unsubscribe_callback
self.period = period
self._attributes = None
self._config = CaselessDict()
self._last_event = TTLDict(default_ttl=10)
self.attribute_validator = TangoAttributeNameValidator()
self.device_validator = TangoDeviceNameValidator()
self.eval_validator = EvaluationAttributeNameValidator()
self.lock = Lock()
self.stopped = Event()
