当另一个线程完成时停止一个线程。

Question

我正在尝试运行 2 个线程，第一个线程有一个 function1 目标，这个函数应该从机器读取一个值，当这个值 =0 时，输出 0 保存在一个数组中。当此值不再为 0 时，输出 1 应保存在此数组中。然后队列必须返回这个列表。第二个线程有一个function2作为目标，这个函数正在做其他事情。我将尝试在以下代码中显示它：

import threading
from multiprocessing import Queue
def func1(queue_in):
    list=[]
    while value_from_machine==0: #this value will always be refreshed and read again
        list.append(0)
        queue_in.put(list) 
    list.append(1) #when the value from the machine is not 0 anymore, put a 1 in the list
    queue_in.put(list)

def func2():
    #doing something else...

q_out=Queue()

thread1=threading.Thread(target=func1,args=(q_out))
thread2=threading.Thread(target=func2)

thread1.start()
thread2.start()

q_value=q_out.get()

if sum(q_value)==1:
    #print something
else:
    #print something else

现在的问题是我希望第一个线程在第二个线程完成后停止。另一件事是我不确定队列是第一个函数中的输出。在while循环中有队列好不好？？

Answer 1

标准方法怎么样 - 设置Event？

from threading import Thread, Event
from Queue import Queue
from time import sleep

def func1(queue_in, done):
    while not done.is_set():
        queue_in.put_nowait(1)
        print 'func1 added new item to the queue_in'
        sleep(1)
    print 'func1 has finished'

def func2(done):
    x = 0
    while x < 3:
        sleep(2)
        x += 1
        print 'func2 processed %s item(s)' % x
    print 'func2 has finished'
    done.set()

q_out = Queue()
done  = Event()

thread1 = Thread(target=func1, args=[q_out, done]).start()
thread2 = Thread(target=func2, args=[done]).start()

输出：

func1 added new item to the queue_in
func1 added new item to the queue_in
func2 processed 1 item(s)
func1 added new item to the queue_in
func1 added new item to the queue_in
func2 processed 2 item(s)
func1 added new item to the queue_in
func1 added new item to the queue_in
func2 processed 3 item(s)
func2 has finished
func1 has finished