python 具有无限循环的多进程队列

Question

I create 3 processes and want the function wirte1 to write value 'A,B,C' to queue1,and function read1 read value from queue1 and put it to queue2,in the same time, function read2 read value from queue2, but value B ,C 无法及时从 queue2 中读取，处理完成。

from multiprocessing import Process, Queue,Manager,Pool,Lock
import os, time, random

#向队列1写数据
def write1(q1,lock):
    lock.acquire()
    for value in ['A', 'B', 'C']:
        print ('Put %s to queue111...%s' % (value,str(os.getpid())))
        q1.put(value)
        time.sleep(1)
    lock.release()

#从队列1读取数据并写入队列2
def read1(q1,q2,lock):
    lock.acquire()
    while True:
        time.sleep(1)
        value=q1.get()
        # if value is None:break
        print('Get %s from queue111.%s' % (value,str(os.getpid())))
        q2.put(value)
        print('Put %s to queue222...%s' % (value,str(os.getpid())))
    lock.release()

def read2(q2,lock):
    lock.acquire()
    while True:
        # if not q2.empty() or not q1.empty():
        time.sleep(2)
        value=q2.get(True)
        print('Get %s from queue222.%s' % (value,os.getpid()))
    lock.release()

if __name__=='__main__':
    manager = Manager()
    # 父进程创建Queue，并传给各个子进程：
    q1 = manager.Queue()
    q2 = manager.Queue()
    lock1 = manager.Lock()
    lock2 = manager.Lock()
    lock3 = manager.Lock()
    start=time.time()
    p = Pool()
    # pw = p.apply_async(write1, args=(q1,lock1,))
    pw = Process(target=write1,args=(q1,lock1,))
    # time.sleep(0.5)
    # pr = p.apply_async(read1, args=(q1,q2,lock2,))
    # pr2 = p.apply_async(read2, args=(q2,lock3))
    pr=Process(target=read1,args=(q1,q2,lock2,))
    pr2 = Process(target=read2,args=(q2,lock3,))

    pw.start()
    pr.start()
    pr2.start()

    # p.close()
    # p.join()
    pw.join()
    pr.terminate()
    pr2.terminate()


    end=time.time()
    # print
    print('finished!!')
    print(end-start)

output 是： Put A to queue111...77678 Put B to queue111...77678 Get A from queue111.77680 Put A to queue222...77680 Put C to queue111...77678 Get A from queue222.77681 Get B from queue111.77680 Put B to queue222...77680 Get C from queue111.77680 Put C to queue222...77680 finished.! 3.025238275527954 Put A to queue111...77678 Put B to queue111...77678 Get A from queue111.77680 Put A to queue222...77680 Put C to queue111...77678 Get A from queue222.77681 Get B from queue111.77680 Put B to queue222...77680 Get C from queue111.77680 Put C to queue222...77680 finished.! 3.025238275527954

Answer 1

您不能使用terminate来控制这样的系统：它与完成实际工作竞争。 相反，使您的循环不是无限的，可能通过在每个Queue中使用一个哨兵值（如在一个注释掉的行中）。