variable.py 文件源码

def get_deferred(self, timeout=None):
        once = self.once
        df = defer.Deferred()
        id1 = once.watch(lambda *event: df.callback(event))
        if timeout is not None:
            def do_timeout():
                df.errback(failure.Failure(defer.TimeoutError('in Event.get_deferred')))
                once.unwatch(id1)
                once.unwatch(x)
            delay = reactor.callLater(timeout, do_timeout)
            x = once.watch(lambda *event: delay.cancel())
        return df