Python探索之自定义实现线程池

import queueimport threadingclass ThreadPool(object):  def __init__(self, max_num=20):    self.queue = queue.Queue(max_num) #创建队列，最大数为20    for i in range(max_num):      self.queue.put(threading.Thread) #将类名放入队列中  def get_thread(self):    return self.queue.get() #从队列中取出类名  def add_thread(self):    self.queue.put(threading.Thread) #进类名放入队列中def func(arg, p): #定义一个函数  print(arg)  import time  time.sleep(2)  p.add_thread()pool = ThreadPool(10) #创建对象，并执行该类的构造方法，即将线程的类名放入队列中for i in range(30):  thread = pool.get_thread() #调用该对象的get_thread方法，取出类名  t = thread(target=func, args=(i, pool)) #创建对象，执行func，参数在args中  t.start()

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    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, args, callback = event      try:        result = func(*args)        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):    """    执行完所有的任务后，所有线程停止    """    self.cancel = True    count = len(self.generate_list)    while count:      self.q.put(StopEvent)      count -= 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)    self.q.queue.clear()  @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)# How to usepool = ThreadPool(5)def callback(status, result):  # status, execute action status  # result, execute action return value  passdef action(i):  print(i)for i in range(30):  ret = pool.run(action, (i,), callback)time.sleep(3)print(len(pool.generate_list), len(pool.free_list))print(len(pool.generate_list), len(pool.free_list))pool.close()# pool.terminate()