python 学习笔记简单线程池实现

#!/usr/bin/env python# -*- coding:utf-8 -*-import Queueimport threadingimport contextlibimport timeStopEvent = object()class ThreadPool(object):    def __init__(self, max_num, max_task_num=None):        if max_task_num:            self.q = Queue.Queue(max_task_num)        else:            self.q = Queue.Queue()        self.max_num = max_num  # 最大num        self.cancel = False        self.terminal = False        self.generate_list = []        self.free_list = []    def run(self, func, args, callback=None):        """        线程池执行一个任务        :param func: 任务函数        :param args: 任务函数所需参数        :param callback: 任务执行失败或成功后执行的回调函数，        回调函数有两个参数1、任务函数执行状态；2、任务函数返回值（默认为None，即：不执行回调函数）        :return: 如果线程池已经终止，则返回True否则None        """        if self.cancel:            return        if len(self.free_list) == 0 and len(self.generate_list) < self.max_num:            self.generate_thread()        w = (func, args, callback,)        self.q.put(w)    def generate_thread(self):        """        创建一个线程        """        t = threading.Thread(target=self.call)        t.start()    def call(self):        """        循环去获取任务函数并执行任务函数        """        current_thread = threading.currentThread()        self.generate_list.append(current_thread)        event = self.q.get()        while event != StopEvent:            func, arguments, callback = event            try:                result = func(*arguments)                success = True            except Exception as e:                success = False                result = None            if callback is not None:                try:                    callback(success, result)                except Exception as e:                    pass            with self.worker_state(self.free_list, current_thread):                if self.terminal:                    event = StopEvent                else:                    event = self.q.get()        else:            self.generate_list.remove(current_thread)    def close(self):        """        所有任务完成后，关闭所有进程        """        self.cancel = True        full_size = len(self.generate_list)        while full_size:            self.q.put(StopEvent)            full_size -= 1    def terminate(self):        """        无论是否还有任务，终止线程        """        self.terminal = True        while self.generate_list:            self.q.put(StopEvent)    @contextlib.contextmanager    def worker_state(self, state_list, worker_thread):        """        用于记录线程中正在等待的线程数        """        state_list.append(worker_thread)        try:            yield        finally:            state_list.remove(worker_thread)if __name__ == '__main__':    pool = ThreadPool(10)    def callback(status, result):        print status        print result        pass    def action(i):        print(i * 100)    for i in range(30):        ret = pool.run(action, (i,), callback)    time.sleep(5)    print(len(pool.generate_list), len(pool.free_list))    time.sleep(3)    pool.close()    pool.terminate()