Python的多进程

朴灿烈づ我的快乐病毒、 2022-05-29 13:37 231阅读 0赞

## 简单实现多进程代码 ##

import time
    from multiprocessing import Process   # 导入多线程模块
    
    class MyProcess(Process):
    
        def __init__(self,num):
            super(MyProcess,self).__init__()
    
            self.num=num
    
        def run(self):   # 必须重写run函数
            time.sleep(1)
            print(self.pid)    # 获取进程号
            print(self.is_alive())   # 判断进程是否执行
            print(self.num)        
            time.sleep(1)
    
    if __name__ == '__main__':
        p_list=[]
        for i in range(10):   
            p = MyProcess(i)     # 创建进程 
            #p.daemon=True # 是否设置为守护进程
            p_list.append(p)
    
        for p in p_list:
            p.start()      # 启动进程
        # for p in p_list:
        # p.join()
    
        print('main process end')

## 进程同步 ##

from multiprocessing import Process, Lock
    import time
    
    def f(l, i):
    
            l.acquire()   # 获取锁
            time.sleep(1)
            print('hello world %s' % i)
            l.release()   # 释放锁
    
    if __name__ == '__main__':
        lock = Lock()    # 进程锁
    
        for num in range(10):
            Process(target=f, args=(lock, num)).start()

## 进程池 ##

from  multiprocessing import Process,Pool
    import time,os
    
    def Foo(i):
    
        time.sleep(1)
        print(i)
        print("son",os.getpid())
    
        return "HELLO %s"%i
    
    
    def Bar(arg):
        print(arg)
        # print("hello")
        # print("Bar:",os.getpid())
    
    if __name__ == '__main__':
    
        pool = Pool(5)   # 设定进程池的大小为5
        print("main pid",os.getpid())
        for i in range(100):
            #pool.apply(func=Foo, args=(i,)) #同步接口
            #pool.apply_async(func=Foo, args=(i,))
    
            #回调函数callback： 就是某个动作或者函数执行成功后再去执行的函数
            pool.apply_async(func=Foo, args=(i,),callback=Bar)
    
        pool.close()
        pool.join()         # join与close调用顺序是固定的
    
        print('end')

## 基本进程间通信 ##

import queue,time
    
    import multiprocessing
    def foo(q):
        time.sleep(1)
        print("son process",id(q))
        q.put(123)
        q.put("yuan")
    
    if __name__ == '__main__':
        #q=queue.Queue()
        q=multiprocessing.Queue()
        p=multiprocessing.Process(target=foo,args=(q,))
        p.start()
        #p.join()
        print("main process",id(q))
        print(q.get())
        print(q.get())