class Counter:
    def __init__(self, start=0, increment=1):
        self.counter = start
        self.increment = increment
        self.lock = threading.RLock()
    def __call__(self):
        self.lock.acquire()
        self.counter += self.increment
        i = self.counter
        self.lock.release()
        return i
    def Get(self):
        self.lock.acquire()
        i = self.counter
        self.lock.release()
        return i
    def Clear(self):
        self.lock.acquire()
        self.counter = 0
        i = self.counter
        self.lock.release()
        return i