Python3下multiprocessing多进程实现，并用Pipe实施进程间通信

'''
An SIMPLE, BRUTAL Demostration for multiprocessing on Python3.
Pipe used for interprocess communications.

Tips:
    Run this demo in a shell to get the messages printed.
    This demo shows nothing if you run it in idle3 or spyder3.
'''

from multiprocessing import Process, Pipe
import time


def Motion(conn_motion):
    '''
    Data generator/sender 1.
    '''
    while True:
        s = "motion function %s"%time.ctime()
        print('>>>>', s)
        conn_motion.send(s)
        time.sleep(1.3)
        

def GPS(conn_gps):
    '''
    Data generator/sender 2.
    '''
    while True:
        s = "gps    function %s"%time.ctime()
        print('>>>>', s)
        conn_gps.send(s)
        
        time.sleep(2.3)
        

def Worker(conn_motion, conn_gps):
    '''
    Data receiver/processer.
    '''
    while True:
        print('-'*40)
        if conn_motion.poll(): # to avoid blocking of recv.
            s = conn_motion.recv()
            print('<<<<', s)
            
        if conn_gps.poll():
            s = conn_gps.recv()
            print('<<<<', s)

        time.sleep(0.1)
        

def Main():
    conn_motion_1, conn_motion_2 = Pipe()
    conn_gps_1,    conn_gps_2    = Pipe()

    p_motion = Process(target=Motion, args=(conn_motion_1,))
    p_gps    = Process(target=GPS,    args=(conn_gps_1,))
    p_worker = Process(target=Worker, args=(conn_motion_2, conn_gps_2,))

    p_motion.start()
    p_gps.start()
    p_worker.start()

    p_motion.join()
    p_gps.join()
    p_worker.join()
    
if __name__ == '__main__':
    Main()