Python Multi-process multithreaded data sharing

Tag:python    thread queue.queue    process multiprocess.queue   

#!/usr/bin/env python# -*- coding:utf-8 -*-# author: changhua gongfrom  multiprocessing import process, queueimport os, time, random ' 1.  We usually from queue import queue are thread-to-column, used for data sharing, and can only be used between threads;2. from multiprocessing  Import queue, which is a process-to-column, is used for inter-process data exchange, in fact the same data is modified between processes for serialization and deserialization (pickle)     completion of data interaction;3.  threads need to be locked , while data transfer between processes is only transitive (data sharing). "' #  Write Data Process Execution code: def write (q):     print (' process to write: %s '  % os.getpid ())     for value in [' A ',  ' B ',  ' C ']:         print (' Put %s to queue ... '  % value)          q.put (value)   #  push          time.sleep (Random.random ()) #  read data Process Execution code: def read (q):     print ( ' Process to read: %s '  % os.getpid ())     while True:         value = q.get (True)   #  get          print (' Get %s from queue. ')  % value) if __name__== ' __main__ ':    #  parent process creates a queue and passes it to each child process:     q = queue ()     pw = process (target=write, args= (q,))     pr = process (target=read, args= (q,))     #  Start child process PW, write:     pw.start ()     #  start child process PR, read:     pr.start ()     #  wait for PW to end:     pw.join ()      # PR process is a dead loop, unable to wait for its end, can only forcibly terminate:     pr.terminate ()          #!/usr/bin/env python# -*- coding:utf-8 -*-# author: changhua gongfrom multiprocessing import process, pipefrom  Time import sleepfrom multiprocessing import freeze_support ' Def Pipe (duplex= True):     return connection (),  connection () explains the problem: the pipe can only interact between two processes, like the phone line form and send and receive "Def  RUN_A (conn):     for i in range (3):         conn.send ("i am from run_a: %s"  % i)          sleep (0.3)     for i in range (5):         print (Conn.recv ()) Def run_b (conn):    for i  In range (3):         print (Conn.recv ())     for  i in range (5):         conn.send ("I am from  run_b: %s "&nbsP;%  i)         sleep (0.3) if __name__ ==  "__ Main__ ":     freeze_support ()     conn1, conn2 = pipe ()     pa = process (target=run_a, args= (CONN1,))     PB  = process (target=run_b, args= (CONN2,))     pa.start ()      pb.start ()     pa.join ()     pb.join ()

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Python Multi-process multithreaded data sharing