本文介绍了线程和信息传递--如何的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
为了避免混淆，我编辑了问题：
one.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
为什么？
我在这里到底遗漏了什么？
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
推荐答案
让我们从一个例子开始：
Thread子类：
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
with语句是获取和释放锁的智能方法，请查看doc。
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
count执行什么操作，self.count如何保持不变。此行为的原因是调用：
dev = Dev(work_q, q_lock, count)
或
dev = Dev(work_q, q_lock, 1)
是一样的。
Arnold Moon向您展示了更改self.count的方法。根据我们的示例进行调整：
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
在我们的运行代码中调用set_count将更改self.count的值：
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()
我希望这将帮助您澄清一些疑虑。
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