# Copyright (c) OpenMMLab. All rights reserved.

import ctypes

import random

import string

def get_random_string(length=15):

    """Get random string with letters and digits.

    Args:

        length (int): Length of random string. Default: 15.

    """

    return ''.join(

        random.choice(string.ascii_letters + string.digits)

        for _ in range(length))

def get_thread_id():

    """Get current thread id."""

    # use ctype to find thread id

    thread_id = ctypes.CDLL('libc.so.6').syscall(186)

    return thread_id

def get_shm_dir():

    """Get shm dir for temporary usage."""

    return '/dev/shm'