5

为了摆脱混乱，我编辑了这个问题：

一个.py

import threading
count = 5
dev = threading.Thread(name='dev', target=dev,args=(workQueue,count,))
dev.setDaemon(True)
dev.start()
workQueue = Queue.Queue(10)
queueLock.acquire()
workQueue.put(word)
queueLock.release()
count = 3
time.sleep(2)
count = 5

但我在这里的困惑是我能够从线程之间的队列中放置和获取值，但在计数的情况下它不会反映。

这是为什么？
这里实际上缺少什么？

class dev ( threading.Thread ):
    def test(self):
        while 1:
            print count
            print self.EPP_Obj
            queueLock.acquire()
            if not self.workQueue.empty():
                data = self.workQueue.get()
                print data
                queueLock.release()
            else:
                queueLock.release()

    def __init__(self, workQueue, EPP_Obj):
        threading.Thread.__init__(self)
        self.workQueue = workQueue
        self.EPP_Obj = EPP_Obj
4

2 回答 2

7

让我们从一个例子开始：

子类Thread：

import threading

class Dev(threading.Thread):

    def __init__(self, workQueue, queueLock, count):
        super(Dev, self).__init__()   # super() will call Thread.__init__ for you
        self.workQueue = workQueue
        self.queueLock= queueLock
        self.count = count

    def run(self):  # put inside run your loop
        data = ''
        while 1:
            with self.queueLock:
                if not self.workQueue.empty():
                    data = self.workQueue.get()
                    print data
                    print self.count

            if data == 'quit':
                break

该with语句是获取和释放锁的一种聪明方法，请查看文档。

现在运行代码：

import Queue
import time

work_q = Queue.Queue()     # first create your "work object"
q_lock = threading.Lock()
count = 1

dev = Dev(work_q, q_lock, count)  # after instantiate like this your Thread
dev.setDaemon(True)
dev.start()

time.sleep(1)
with q_lock:
    work_q.put('word')
# word
# 1

time.sleep(1)
count = 10
with q_lock:
    work_q.put('dog')
# dog
# 1

count = 'foo'
with q_lock:
    work_q.put('quit')
# quit
# 1

dev.join()   # This will prevent the main to exit
             # while the dev thread is still running

通过上面的代码，我们有一个清晰的例子，说明self.count无论我们做什么都保持不变count。
这种行为的原因是调用：

dev = Dev(work_q, q_lock, count)

或者

dev = Dev(work_q, q_lock, 1)

是一样的。

Arnold Moon向您展示了改变的方法self.count。将其调整为我们的示例：

class Dev(threading.Thread):

    def __init__(self, workQueue, queueLock, count):
        super(Dev, self).__init__()
        self.workQueue = workQueue
        self.queueLock= queueLock
        self.count = count

    def set_count(self, value):
        self.count = value

    def run(self):
        data = ''
        while 1:
            with self.queueLock:
                if not self.workQueue.empty():
                    data = self.workQueue.get()
                    print data
                    print self.count

            if data == 'quit':
                break

调用set_count我们的运行代码将改变 的值self.count：

time.sleep(1)
with q_lock:
    work_q.put('word')
# word
# 1

time.sleep(1)
count = dev.count + 9
dev.set_count(count)
with q_lock:
    work_q.put('dog')
# dog
# 10

count = 'foo'
with q_lock:
    work_q.put('quit')
# quit
# 10
dev.join()

我希望这可以帮助您澄清一些疑问。

于 2012-02-08T20:39:08.027 回答
4

我希望这能帮到您。我想你不知道你需要使用哪种方式。python中的多线程有一些方法。我介绍了使用类的方式。你运行下面的代码。你会明白的。

主文件

import stringRepeater
import Queue

workqueue = Queue.Queue()
workqueue.put('test1')
workqueue.put('test2')
workqueue.put('test3')

th = stringRepeater.stringRepeater(workqueue,5)
th.start()
print '----daemon is on ----'
th.setCount(3)
workqueue.put('test4')
workqueue.put('test5')

字符串中继器.py

import threading

class stringRepeater(threading.Thread):
    def __init__(self, workQueue, count):
        threading.Thread.__init__(self)
        self.workQueue = workQueue
        self.repeatCount = count

    def run(self):
        while True:
            teststring = self.workQueue.get()
            for i in range(self.repeatCount):
                print teststring

    def setCount(self, newcount):
        self.repeatCount = newcount
于 2012-02-08T09:37:22.277 回答