Python的multiprocessing模塊提供了多種進(jìn)程間通信的方式，如Queue、Pipe等。

Queue是multiprocessing提供的一個模塊，它的數(shù)據(jù)結(jié)構(gòu)就是"FIFO——first in first out"的隊(duì)列，常用的方法有：put(object)入隊(duì)；get()出隊(duì)；empty()判斷隊(duì)列是否為空。Lock：當(dāng)多個子進(jìn)程對同一個queue執(zhí)行寫操作時，為了避免并發(fā)操作產(chǎn)生沖突，可以通過加鎖的方式使得某個子進(jìn)程對queue擁有唯一的寫權(quán)限，其他子進(jìn)程必須等待該鎖釋放后才能再開始執(zhí)行寫操作。

下面就是使用Queue進(jìn)行進(jìn)程間通信的代碼：在父進(jìn)程里創(chuàng)建兩個子進(jìn)程，分別實(shí)現(xiàn)對queue的讀和寫操作：

#!/usr/bin/python
# -*- coding: utf-8 -*
__author__ = 'zni.feng'
import  sys
reload (sys)
sys.setdefaultencoding('utf-8')
from multiprocessing import Process, Queue, Lock
import os, time, random
#寫數(shù)據(jù)進(jìn)程
def write(q, lock, name):print 'Child Process %s starts' % name#獲得鎖lock.acquire()for value in ['A' , 'B', 'C']:print 'Put %s to queue...' % valueq.put(value)time.sleep(random.random())#釋放鎖lock.release()print 'Child Process %s ends' % name#讀數(shù)據(jù)進(jìn)程
def read(q, lock, name):print 'Child Process %s starts' % namewhile True: #持續(xù)地讀取q中的數(shù)據(jù)value =q.get()print 'Get %s from queue.' % valueprint 'Child Process %s ends' % nameif __name__ == "__main__":#父進(jìn)程創(chuàng)建queue，并共享給各個子進(jìn)程q= Queue()#創(chuàng)建鎖lock = Lock()#創(chuàng)建第一個“寫”子進(jìn)程pw = Process(target = write , args=(q, lock, 'WRITE', ))#創(chuàng)建“讀”進(jìn)程pr = Process(target = read, args=(q,lock, 'READ',))#啟動子進(jìn)程pw,寫入：pw.start()#啟動子進(jìn)程pr，讀取：pr.start()#等待pw結(jié)束：pw.join()#pr是個死循環(huán)，通過terminate殺死：pr.terminate()print 'Test finish.'

運(yùn)行結(jié)果：

Child Process WRITE starts
Put A to queue...
Child Process READ starts
Get A from queue.
Put B to queue...
Get B from queue.
Put C to queue...
Get C from queue.
Child Process WRITE ends
Test finish.
[Finished in 2.0s]Pipe是另一種進(jìn)程間通信的方式，俗稱“管道”。它由兩端組成，一端往管道里寫入數(shù)據(jù)，另一端從管道里讀取數(shù)據(jù)。

下面就是使用Pipe通信的代碼：

#!/usr/bin/python
# -*- coding: utf-8 -*
__author__ = 'zni.feng'
import  sys
reload (sys)
sys.setdefaultencoding('utf-8')
from multiprocessing import Process, Pipe
import os, time, random#發(fā)送數(shù)據(jù)進(jìn)程
def send(child_pipe, name):print 'Child Process %s starts' % namechild_pipe.send('This is Mr.Ni')child_pipe.close()time.sleep(random.random())print 'Child Process %s ends' % name#接收數(shù)據(jù)進(jìn)程
def recv(parent_pipe, name):print 'Child Process %s starts' % nameprint parent_pipe.recv()time.sleep(random.random())print 'Child Process %s ends' % nameif __name__ == "__main__":#創(chuàng)建管道parent,child = Pipe()#創(chuàng)建send進(jìn)程ps = Process(target=send, args=(child, 'SEND'))#創(chuàng)建recv進(jìn)程pr = Process(target=recv, args=(parent, 'RECEIVE'))#啟動send進(jìn)程ps.start()#等待send進(jìn)程結(jié)束ps.join()#啟動recv進(jìn)程pr.start()#等待recv進(jìn)程結(jié)束pr.join()print 'Test finish.'

運(yùn)行結(jié)果：

Child Process SEND starts
Child Process SEND ends
Child Process RECEIVE starts
This is Mr.Ni
Child Process RECEIVE ends
Test finish.
[Finished in 1.8s]