# Copyright 2020 Huawei Technologies Co., Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ============================================================================
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'