Python中线程池的实现(三)详解编程语言

# -*- coding: utf-8 -*- 
 
# Java 理论与实践: 线程池与工作队列: http://www.ibm.com/developerworks/cn/java/j-jtp0730/ 
# 线程池原理及python实现: http://www.cnblogs.com/goodhacker/p/3359985.html 
# Threadpool: http://chrisarndt.de/projects/threadpool/ 
#             http://www.cnblogs.com/coser/archive/2012/03/10/2389264.html 
 
import Queue 
import threading 
 
class ThreadPool(object): 
    def __init__(self, maxsize=4, timeout=1): 
        self._maxsize = maxsize 
        self._timeout = timeout 
        self._threads = [] 
        self._work_queue = Queue.Queue() 
        self._create_threads() 
    def execute(self, func, *args, **kwargs): 
        self._work_queue.put((func, args, kwargs)) 
        # self._append_thread() 
    def dismiss(self, do_join=False): 
        dismiss_list = [] 
        for i in range(len(self._threads)): 
            thread = self._threads.pop() 
            thread.dismiss() 
            dismiss_list.append(thread) 
        if do_join: 
            for thread in dismiss_list: 
                thread.join() 
    def _create_threads(self): 
        for i in range(self._maxsize): 
            self._threads.append(WorkThread(self._work_queue, self._timeout)) 
    # def _append_thread(self): 
    #     num_thread = len(self._threads) 
    #     if num_thread == self._maxsize: 
    #         return 
    #     num_work = self._work_queue.qsize() 
    #     if num_thread >= num_work: 
    #         return 
    #     for i in range(num_thread, min(num_work, self._maxsize)): 
    #         self._threads.append(WorkThread(self._work_queue, self._timeout)) 
 
class WorkThread(threading.Thread): 
    def __init__(self, work_queue, timeout=1): 
        super(WorkThread, self).__init__() 
        self._work_queue = work_queue 
        self._timeout = timeout 
        self._dismissed = threading.Event() 
        self.start() 
    def run(self): 
        while True: 
            if self._dismissed.isSet() / 
                    and self._work_queue.qsize() == 0: 
                break 
            try: 
                func, args, kwargs = self._work_queue.get(True, self._timeout) 
            except Queue.Empty: 
                continue 
            else: 
                func(*args, **kwargs) 
        # print("%s exited!" % threading.current_thread()) 
    def dismiss(self): 
        self._dismissed.set() 
 
if __name__ == '__main__': 
    import time 
 
    def do_sth(n): 
        time.sleep(0.1) 
        print("task%s in %s" % (n, threading.current_thread())) 
 
    pool = ThreadPool() 
    for i in range(0, 20): 
        pool.execute(do_sth, i) 
    pool.dismiss(True) 
 
    print("completed!")