Wraps a `.Future` (or other yieldable object) in a timeout.

    Raises `tornado.util.TimeoutError` if the input future does not
    complete before ``timeout``, which may be specified in any form
    allowed by `.IOLoop.add_timeout` (i.e. a `datetime.timedelta` or
    an absolute time relative to `.IOLoop.time`)

    If the wrapped `.Future` fails after it has timed out, the exception
    will be logged unless it is of a type contained in ``quiet_exceptions``
    (which may be an exception type or a sequence of types).

    The wrapped `.Future` is not canceled when the timeout expires,
    permitting it to be reused. `asyncio.wait_for` is similar to this
    function but it does cancel the wrapped `.Future` on timeout.

    .. versionadded:: 4.0

    .. versionchanged:: 4.1
       Added the ``quiet_exceptions`` argument and the logging of unhandled
       exceptions.

    .. versionchanged:: 4.4
       Added support for yieldable objects other than `.Future`.

def with_timeout(
    timeout: Union[float, datetime.timedelta],
    future: _Yieldable,
    quiet_exceptions: "Union[Type[Exception], Tuple[Type[Exception], ...]]" = (),
) -> Future:
    """Wraps a `.Future` (or other yieldable object) in a timeout.

    Raises `tornado.util.TimeoutError` if the input future does not
    complete before ``timeout``, which may be specified in any form
    allowed by `.IOLoop.add_timeout` (i.e. a `datetime.timedelta` or
    an absolute time relative to `.IOLoop.time`)

    If the wrapped `.Future` fails after it has timed out, the exception
    will be logged unless it is of a type contained in ``quiet_exceptions``
    (which may be an exception type or a sequence of types).

    The wrapped `.Future` is not canceled when the timeout expires,
    permitting it to be reused. `asyncio.wait_for` is similar to this
    function but it does cancel the wrapped `.Future` on timeout.

    .. versionadded:: 4.0

    .. versionchanged:: 4.1
       Added the ``quiet_exceptions`` argument and the logging of unhandled
       exceptions.

    .. versionchanged:: 4.4
       Added support for yieldable objects other than `.Future`.

    """
    # It's tempting to optimize this by cancelling the input future on timeout
    # instead of creating a new one, but A) we can't know if we are the only
    # one waiting on the input future, so cancelling it might disrupt other
    # callers and B) concurrent futures can only be cancelled while they are
    # in the queue, so cancellation cannot reliably bound our waiting time.
    future_converted = convert_yielded(future)
    result = _create_future()
    chain_future(future_converted, result)
    io_loop = IOLoop.current()

    def error_callback(future: Future) -> None:
        try:
            future.result()
        except Exception as e:
            if not isinstance(e, quiet_exceptions):
                app_log.error(
                    "Exception in Future %r after timeout", future, exc_info=True
                )

    def timeout_callback() -> None:
        if not result.done():
            result.set_exception(TimeoutError("Timeout"))
        # In case the wrapped future goes on to fail, log it.
        future_add_done_callback(future_converted, error_callback)

    timeout_handle = io_loop.add_timeout(timeout, timeout_callback)
    if isinstance(future_converted, Future):
        # We know this future will resolve on the IOLoop, so we don't
        # need the extra thread-safety of IOLoop.add_future (and we also
        # don't care about StackContext here.
        future_add_done_callback(
            future_converted, lambda future: io_loop.remove_timeout(timeout_handle)
        )
    else:
        # concurrent.futures.Futures may resolve on any thread, so we
        # need to route them back to the IOLoop.
        io_loop.add_future(
            future_converted, lambda future: io_loop.remove_timeout(timeout_handle)
        )
    return result