Python并发进程—multiprocessing 模块创建进程

 1 import multiprocessing as mp
 2 from time import sleep
 3 
 4 a = 1
 5 
 6 def fun():
 7   print("开始一个新的进程")
 8   sleep(5)
 9   global  a
10   print("a = ",a)
11   a = 10000
12   print("子进程结束了")
13 
14 # 创建进程对象
15 p = mp.Process(target = fun)
16 p.start()  # 启动进程
17 
18 sleep(2)
19 print("父进程干点啥")
20 
21 p.join(1) # 回收进程
22 
23 print(‘a:‘,a)
24 
25 # 等价于如下
26 # pid = os.fork()
27 # if pid == 0:
28 #   fun()
29 # else:
30 #   os.wait()

 1 from multiprocessing import Process
 2 from time import sleep
 3 import os
 4 
 5 def th1():
 6   sleep(3)
 7   print("吃饭")
 8   print(os.getppid(),‘---‘,os.getpid())
 9 
10 def th2():
11   sleep(2)
12   print("睡觉")
13   print(os.getppid(),‘---‘,os.getpid())
14 
15 def th3():
16   sleep(4)
17   print("打豆豆")
18   print(os.getppid(),‘---‘,os.getpid())
19 
20 things = [th1,th2,th3]
21 jobs = []
22 for th in things:
23   p = Process(target = th)
24   p.start()
25   jobs.append(p)  # 将进程对象保存在列表
26 
27 # 一起回收
28 for i in jobs:
29   i.join()

 1 from multiprocessing import Process
 2 from time import sleep
 3 
 4 # 带参数的进程函数
 5 def worker(sec,name):
 6   for i in range(3):
 7     sleep(sec)
 8     print("I‘m %s"%name)
 9     print("I‘m working ... ")
10 
11 # p = Process(target=worker,args=(2,‘Baron‘))
12 p = Process(target = worker,args=(2,),
13             kwargs={‘name‘:‘Baron‘})
14 p.start()
15 p.join()

 1 from multiprocessing import Process
 2 from time import sleep,ctime
 3 
 4 def tm():
 5   for i in range(3):
 6     sleep(2)
 7     print(ctime())
 8 
 9 p = Process(target = tm,name = ‘Tedu‘)
10 
11 p.daemon = True # 子进程会随父进程退出
12 
13 p.start()
14 print("Name:",p.name)  # 名称
15 print("PID:",p.pid)  # PID
16 print("Is alive:",p.is_alive()) # 生命周期