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进程对列Queue

from multiprocessing import Process, Queue
import queue

def f(q,n):
    #q.put([123, 456, 'hello'])
    q.put(n*n+1)
    print("son process",id(q))

if __name__ == '__main__':
    q = Queue()  #try: q=queue.Queue()
    print("main process",id(q))

    for i in range(3):
        p = Process(target=f, args=(q,i))
        p.start()

    print(q.get())
    print(q.get())
    print(q.get())

管道

The Pipe() function returns a pair of connection objects connected by a pipe which by default is duplex (two-way). For example:
from multiprocessing import Process, Pipe

def f(conn):
    conn.send([12, {"name":"yuan"}, 'hello'])
    response=conn.recv()
    print("response",response)
    conn.close()
    print("q_ID2:",id(child_conn))

if __name__ == '__main__':

    parent_conn, child_conn = Pipe()
    print("q_ID1:",id(child_conn))
    p = Process(target=f, args=(child_conn,))
    p.start()
    print(parent_conn.recv())   # prints "[42, None, 'hello']"
    parent_conn.send("儿子你好!")
    p.join()
The two connection objects returned by Pipe() represent the two ends of the pipe. Each connection object has send() and recv() methods (among others). Note that data in a pipe may become corrupted if two processes (or threads) try to read from or write to the same end of the pipe at the same time.
Of course there is no risk of corruption from processes using different ends of the pipe at the same time.

Managers


Queue和pipe只是实现了数据交互,并没实现数据共享,即一个进程去更改另一个进程的数据。

A manager object returned by Manager() controls a server process which holds Python objects and allows other processes to manipulate them using proxies.

A manager returned by Manager() will support types listdictNamespaceLockRLockSemaphoreBoundedSemaphoreConditionEventBarrierQueueValue and Array. For example:

from multiprocessing import Process, Manager

def f(d, l,n):
    d[n] = '1'
    d['2'] = 2
    d[0.25] = None
    l.append(n)
    #print(l)

    print("son process:",id(d),id(l))

if __name__ == '__main__':

    with Manager() as manager:

        d = manager.dict()

        l = manager.list(range(5))

        print("main process:",id(d),id(l))

        p_list = []

        for i in range(10):
            p = Process(target=f, args=(d,l,i))
            p.start()
            p_list.append(p)

        for res in p_list:
            res.join()

        print(d)
        print(l)
 
posted on 2018-02-03 20:30  思南1900  阅读(141)  评论(0编辑  收藏  举报