用python实现的线程池实例代码

# coding:utf-8 import Queueimport threadingimport sysimport timeimport math  class WorkThread(threading.Thread):   def __init__(self, task_queue):    threading.Thread.__init__(self)    self.setDaemon(True)    self.task_queue = task_queue    self.start()    self.idle = True   def run(self):    sleep_time = 0.01 # 第1次无任务可做时休息10毫秒    multiply = 0    while True:      try:        # 从队列中取一个任务        func, args, kwargs = self.task_queue.get(block=False)        self.idle = False        multiply = 0        # 执行之        func(*args, **kwargs)      except Queue.Empty:        time.sleep(sleep_time * math.pow(2, multiply))        self.idle = True        multiply += 1        continue      except:        print sys.exc_info()        raise  class ThreadPool:   def __init__(self, thread_num=10, max_queue_len=1000):    self.max_queue_len = max_queue_len    self.task_queue = Queue.Queue(max_queue_len) # 任务等待队列    self.threads = []    self.__create_pool(thread_num)   def __create_pool(self, thread_num):    for i in xrange(thread_num):      thread = WorkThread(self.task_queue)      self.threads.append(thread)   def add_task(self, func, *args, **kwargs):    '''添加一个任务，返回任务等待队列的长度      调用该方法前最后先调用isSafe()判断一下等待的任务是不是很多，以防止提交的任务被拒绝    '''    try:      self.task_queue.put((func, args, kwargs))    except Queue.Full:      raise # 队列已满时直接抛出异常，不给执行    return self.task_queue.qsize()   def isSafe(self):    '''等待的任务数量离警界线还比较远    '''    return self.task_queue.qsize() < 0.9 * self.max_queue_len   def wait_for_complete(self):    '''等待提交到线程池的所有任务都执行完毕    '''    #首先任务等待队列要变成空    while not self.task_queue.empty():      time.sleep(1)    # 其次，所以计算线程要变成idle状态    while True:      all_idle = True      for th in self.threads:        if not th.idle:          all_idle = False          break      if all_idle:        break      else:        time.sleep(1)  if __name__ == '__main__':  def foo(a, b):    print a + b    time.sleep(0.01)  thread_pool = ThreadPool(10, 100)  '''在Windows上测试不通过，Windows上Queue.Queue不是线程安全的'''  size = 0  for i in xrange(10000):    try:      size = thread_pool.add_task(foo, i, 2 * i)    except Queue.Full:      print 'queue full, queue size is ', size  time.sleep(2)