'''python'''
# -*- coding: utf-8 -*
import threading
class Singleton(object):
    _instance_lock = threading.Lock()

    def __init__(self):
        pass

    def __new__(cls, *args, **kwargs):
        if not hasattr(Singleton, "_instance"):
            with Singleton._instance_lock:
                if not hasattr(Singleton, "_instance"):
                    Singleton._instance = object.__new__(cls)
        return Singleton._instance
obj1 = Singleton()
obj2 = Singleton()
print(obj1, obj2)
def task(arg):
    obj = Singleton()
    print(obj)