Function busy_retry

Lib/test/support/__init__.py:2682–2721

Run the loop body until "break" stops the loop. After *timeout* seconds, raise an AssertionError if *error* is true, or just stop if *error is false. Example: for _ in support.busy_retry(support.SHORT_TIMEOUT): if check(): break Example of

(timeout, err_msg=None, /, *, error=True)

def busy_retry(timeout, err_msg=None, /, *, error=True):
    """
    Run the loop body until "break" stops the loop.

    After *timeout* seconds, raise an AssertionError if *error* is true,
    or just stop if *error is false.

    Example:

        for _ in support.busy_retry(support.SHORT_TIMEOUT):
            if check():
                break

    Example of error=False usage:

        for _ in support.busy_retry(support.SHORT_TIMEOUT, error=False):
            if check():
                break
        else:
            raise RuntimeError('my custom error')

    """
    if timeout <= 0:
        raise ValueError("timeout must be greater than zero")

    start_time = time.monotonic()
    deadline = start_time + timeout

    while True:
        yield

        if time.monotonic() >= deadline:
            break

    if error:
        dt = time.monotonic() - start_time
        msg = f"timeout ({dt:.1f} seconds)"
        if err_msg:
            msg = f"{msg}: {err_msg}"
        raise AssertionError(msg)


def sleeping_retry(timeout, err_msg=None, /,