#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Backport of Event from py2.7 (method wait in py2.6 returns None)

from builtins import object
from threading import Condition, Lock


class Event(object):

    def __init__(self,):
        self.__cond = Condition(Lock())
        self.__flag = False

    def isSet(self):
        return self.__flag

    is_set = isSet

    def set(self):
        self.__cond.acquire()
        try:
            self.__flag = True
            self.__cond.notify_all()
        finally:
            self.__cond.release()

    def clear(self):
        self.__cond.acquire()
        try:
            self.__flag = False
        finally:
            self.__cond.release()

    def wait(self, timeout=None):
        self.__cond.acquire()
        try:
            if not self.__flag:
                self.__cond.wait(timeout)
            return self.__flag
        finally:
            self.__cond.release()