python 用线程 Queue时，有个线程没工作感觉，咋回事

[色郎中]

再学习python时，网上找了段代码，作了些修改
前两天刚弄完时，程序还正常的，生产者和消费者确打印信息出来的，只是，消费者开5个线程时，只有一个线程能打印消息


今天再跑时，发现更不正常了
一个生产者，一个消费者，程序跑起来后，消费者线程的信息没有打印出来（在消费者线程里，断点时，能打印一次信息出来）

class consumer(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)
        self.setName("new" + self.name)

    def run(self):
        global queue
        while queue.qsize() > 0:
            msg = self.name + '    consumer    ' + queue.get()+ "get Queue Size: "+ str(queue.qsize())
            print msg
            time.sleep(5)

class produce(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)
        self.setName("new"+self.name)

    def run(self):
        global queue
        b = os.path.exists(".\\testFile\\")
        if b:
            print "File direction Exist!"
        else:
            os.mkdir(".\\testFile\\")
        while True:
            for i in range(1, 1 + 1):
                localTime = time.strftime("%Y%m%d%H%M%S", time.localtime())
                filename = ".\\testFile\\" + localTime + ".txt"
                f = open(filename, 'ab')
                testnote = 'test file'
                f.write(testnote)
                f.close()
                queue.put(filename)
                print "file" + " " + str(i) + ":" + str(localTime) + ".txt"+ "put Queue Size: "+ str(queue.qsize())
                time.sleep(1)
            #print "ALL Down"
            time.sleep(1)



def threadTest():
    p = produce()
    c = consumer()
    p.start()
    c.start()
    p.join()
    c.join()


if __name__ == '__main__':
    threadTest()

结果如下：

C:\Python27\python.exe E:/2017/queueExample/queueExample.py
File direction Exist!
file 1:20170401113753.txtput Queue Size: 1
file 1:20170401113755.txtput Queue Size: 2
file 1:20170401113757.txtput Queue Size: 3
file 1:20170401113759.txtput Queue Size: 4
file 1:20170401113801.txtput Queue Size: 5

[色郎中]

又把网上例子跑了下，正常 我修改的代码，区别 1 修改的代码里，线程中 一直产生文件， 网上例子做5次 2 Queqe，没有作为参数传入， 而是作为全局变量使用，难道这个会影响？

# producer_consumer_queue

from Queue import Queue

import random

import threading

import time


# Producer thread

class Producer(threading.Thread):
    def __init__(self, t_name, queue):
        threading.Thread.__init__(self, name=t_name)

        self.data = queue

    def run(self):
        for i in range(5):
            print "%s: %s is producing %d to the queue!\n" % (time.ctime(), self.getName(), i)

            self.data.put(i)

            time.sleep(random.randrange(10) / 5)

        print "%s: %s finished!" % (time.ctime(), self.getName())



        # Consumer thread


class Consumer(threading.Thread):
    def __init__(self, t_name, queue):
        threading.Thread.__init__(self, name=t_name)

        self.data = queue

    def run(self):
        for i in range(5):
            val = self.data.get()

            print "%s: %s is consuming. %d in the queue is consumed!\n" % (time.ctime(), self.getName(), val)

            time.sleep(random.randrange(10))

        print "%s: %s finished!" % (time.ctime(), self.getName())



        # Main thread


def main():
    queue = Queue()

    producer = Producer('Pro.', queue)

    consumer = Consumer('Con.', queue)

    producer.start()

    consumer.start()

    producer.join()

    consumer.join()

    print 'All threads terminate!'


if __name__ == '__main__':
    main()

[色郎中]

class consumer(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)
        self.setName("new" + self.name)
 
    def run(self):
        global queue
        while queue.qsize() > 0:
            msg = self.name + '    consumer    ' + queue.get()+ "get Queue Size: "+ str(queue.qsize())
            print msg
            time.sleep(5)

应该是 while queue.qsize() > 0 这句出了问题， 估计是线程都同时，启动了，消费者里的 queue的大小 为0了，所以没打印消息出来