_runmany.py 文件源码

def _iterate(reactor, intervals, f):
    """
    Run a function repeatedly.

    :param reactor: See ``run_many_service``.

    :return Deferred: A deferred which fires when ``f`` fails or when
        ``intervals`` is exhausted.
    """
    while True:
        before = reactor.seconds()
        yield f()
        after = reactor.seconds()
        try:
            interval = next(intervals)
        except StopIteration:
            break
        delay = max(0, interval - (after - before))
        yield deferLater(reactor, delay, lambda: None)