tasks.py 文件源码

def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
    """Wait for the Futures and coroutines given by fs to complete.

    The sequence futures must not be empty.

    Coroutines will be wrapped in Tasks.

    Returns two sets of Future: (done, pending).

    Usage:

        done, pending = yield from asyncio.wait(fs)

    Note: This does not raise TimeoutError! Futures that aren't done
    when the timeout occurs are returned in the second set.
    """
    if futures.isfuture(fs) or coroutines.iscoroutine(fs):
        raise TypeError("expect a list of futures, not %s" % type(fs).__name__)
    if not fs:
        raise ValueError('Set of coroutines/Futures is empty.')
    if return_when not in (FIRST_COMPLETED, FIRST_EXCEPTION, ALL_COMPLETED):
        raise ValueError('Invalid return_when value: {}'.format(return_when))

    if loop is None:
        loop = events.get_event_loop()

    fs = {ensure_future(f, loop=loop) for f in set(fs)}

    return (yield from _wait(fs, timeout, return_when, loop))