关于MMEngine随机性的一些整理

def set_random_seed(seed: Optional[int] = None,
                    deterministic: bool = False,
                    diff_rank_seed: bool = False) -> int:
    """Set random seed.

    Args:
        seed (int, optional): Seed to be used.
        deterministic (bool): Whether to set the deterministic option for
            CUDNN backend, i.e., set `torch.backends.cudnn.deterministic`
            to True and `torch.backends.cudnn.benchmark` to False.
            Defaults to False.
        diff_rank_seed (bool): Whether to add rank number to the random seed to
            have different random seed in different threads. Defaults to False.
    """
    if seed is None:
        seed = sync_random_seed()

    if diff_rank_seed:
        rank = get_rank()
        seed += rank

    random.seed(seed)
    np.random.seed(seed)
    torch.manual_seed(seed)
    # torch.cuda.manual_seed(seed)
    torch.cuda.manual_seed_all(seed)
    # os.environ['PYTHONHASHSEED'] = str(seed)
    if deterministic:
        if torch.backends.cudnn.benchmark:
            print_log(
                'torch.backends.cudnn.benchmark is going to be set as '
                '`False` to cause cuDNN to deterministically select an '
                'algorithm',
                logger='current',
                level=logging.WARNING)
        torch.backends.cudnn.deterministic = True
        torch.backends.cudnn.benchmark = False

        if digit_version(TORCH_VERSION) >= digit_version('1.10.0'):
            torch.use_deterministic_algorithms(True)
    return seed