python多进程–交互

• 2020 年 1 月 14 日
• 筆記

1.管道使用

'''  管道Pipe  '''  from multiprocessing import Process,Pipe    def f(conn):      conn.send('child message')#给主进程发送消息      conn.close()  if __name__=='__main__':      parent_conn,child_conn=Pipe()      p=Process(target=f,args=(child_conn,))      p.start()      print(parent_conn.recv())#主进程接收子进程消息      p.join()

2.Manage增强版pipe，可以接收字典，列表等

from multiprocessing import Process,Manager  import os    def f(d,l):#处理字典，列表函数      d[1]='1'      d['2']=2        l.append(os.getpid())    if __name__=="__main__":      manage_data=Manager()      d=manage_data.dict()      l=manage_data.list()        p_list=[]      for i in range(10):#建立10个进程并调用公共函数f          p = Process(target=f, args=(d, l))          p.start()          p_list.append(p)        for res in p_list:          res.join()        print(d)      print(l)    >>:  {1: '1', '2': 2}  [2472, 7972, 9760, 5328, 5488, 12316, 6780, 12592, 6676, 6408]      

3.进程池与回调函数

from multiprocessing import Process,Pool  import time  import os    def Foo(i):      time.sleep(2)      print("in process",os.getpid())      return i+100    def Bar(arg):      print("-->exec done:",arg,os.getpid())    if __name__=='__main__':      pool=Pool(processes=2)#同时运行的进程数      print("main process",os.getpid())      for i in range(10):          pool.apply_async(func=Foo,args=(i,),callback=Bar)        pool.close()      pool.join()    >>:  main process 15704  in process 15336  in process 14796  -->exec done: 100 15704  -->exec done: 101 15704  in process 14796  in process 15336  -->exec done: 103 15704  -->exec done: 102 15704  in process 14796  in process 15336  -->exec done: 104 15704  -->exec done: 105 15704  in process 15336  in process 14796  -->exec done: 107 15704  -->exec done: 106 15704  in process 15336  in process 14796  -->exec done: 109 15704  -->exec done: 108 15704