目录

• 代码创建进程
  • 创建进程的方式有哪些
    • 代码创建的两种方式
    • 进程循环
• join方法
• 进程间数据默认隔离
• 进程对象相关属性和方法
  • 查看进程的方法
    • cmd
    • python代码
      • current_process函数
      • os模块
• 僵尸进程与孤儿进程
  • 僵尸进程
  • 孤儿进程
• 守护进程
• 互斥锁

代码创建进程

创建进程的方式有哪些

• 鼠标双击桌面一个应用图标
• 代码创建

代码创建的两种方式

# 第一种代码创建进程的方式 from multiprocessing import Process import time   def task(process_name):     print('the subprocess %s is running' % process_name)     time.sleep(3)     print('the subprocess %s is over' % process_name)   if __name__ == '__main__':     p = Process(target=task, args=('meta',))  # 创建一个进程对象     p.start()  # 创建一个新的进程     print('主进程') # 第二种代码创建进程的方式 from multiprocessing import Process import time   class MyProcess(Process):     def __init__(self, process_name):         self.process_name = process_name         super().__init__()      def run(self):         print('the subprocess %s is running' % self.process_name)         time.sleep(3)         print('the subprocess %s is over' % self.process_name)   if __name__ == '__main__':     p = MyProcess('mi_chat')     p.start()     print('主进程') 

进程循环

# 客户端 import socket   client = socket.socket() client.connect(('127.0.0.1', 8066))  count = 1 send_msg = input('请输入发送的内容:').strip() while count < 9:     client.send(send_msg.encode('utf8'))     data = client.recv(1024)     count += 1     print(data.decode('utf8')) # 服务端 import socket from multiprocessing import Process   def get_server():     server = socket.socket()     server.bind(('127.0.0.1', 8066))     server.listen(4)     return server   def talk(sock):     count = 1     while count < 9:         count += 1         data = sock.recv(1024)         print(data.decode('utf8'))         sock.send(f'我们已经收到您的消息'.encode('utf8'))   if __name__ == '__main__':     server = get_server()     count = 1     while count < 9:         sock, addr = server.accept()         count += 1         p = Process(target=talk, args=(sock,))         p.start() 

join方法

# join方法让主进程代码等待子进程代码运行完毕再执行  from multiprocessing import Process import time   def task(process_name, time_arg):     print(f'the subprocess: {process_name} is running')     time.sleep(time_arg)     print(f'the subprocess: {process_name} is over')   if __name__ == '__main__':     p1 = Process(target=task, args=('qq', 1))     p2 = Process(target=task, args=('tmall', 2))     p3 = Process(target=task, args=('jd', 3))     p4 = Process(target=task, args=('pxx', 4))     start_time = time.time()     p1.start()     p2.start()     p3.start()     p4.start()     p1.join()     p2.join()     p3.join()     p4.join()     end_time = time.time()     sum_time = end_time - start_time     print('主进程', f'总耗时:{sum_time}')  # 主进程 总耗时:4.281822919845581 # start一个join交替执行的情况 from multiprocessing import Process import time   def task(process_name, time_arg):     print(f'the subprocess: {process_name} is running')     time.sleep(time_arg)     print(f'the subprocess: {process_name} is over')   if __name__ == '__main__':     p1 = Process(target=task, args=('qq', 1))     p2 = Process(target=task, args=('tmall', 2))     p3 = Process(target=task, args=('jd', 3))     p4 = Process(target=task, args=('pxx', 4))     start_time = time.time()     p1.start()     p1.join()     p2.start()     p2.join()     p3.start()     p3.join()     p4.start()     p4.join()     end_time = time.time()     sum_time = end_time - start_time     print('主进程', f'总耗时:{sum_time}')  # 主进程 总耗时:10.786401271820068 

进程间数据默认隔离

from multiprocessing import Process  nationality = 'China'   def task():     global nationality     nationality = 'USA'   if __name__ == '__main__':     p = Process(target=task)     p.start()     p.join()  # 目的是子进程代码运行结束再执行打印操作     print(nationality)  # China 

进程对象相关属性和方法

查看进程的方法

cmd

windows: tasklist
mac: ps -ef

python代码

current_process函数

# current_process函数 from multiprocessing import Process,current_process import time   class MyProcess(Process):     def __init__(self, process_name):         self.process_name = process_name         super().__init__()      def run(self):         print('the subprocess %s is running' % self.process_name)         print(current_process().pid)         time.sleep(3)         print('the subprocess %s is over' % self.process_name)   if __name__ == '__main__':     p = MyProcess('mi_chat')     p.start()     print('主进程')     print(current_process().pid) 

os模块

# os模块 from multiprocessing import Process,current_process import time import os  class MyProcess(Process):     def __init__(self, process_name):         self.process_name = process_name         super().__init__()      def run(self):         print('the subprocess %s is running' % self.process_name)         print(os.getpid())         print(os.getppid())         time.sleep(3)         print('the subprocess %s is over' % self.process_name)   if __name__ == '__main__':     p = MyProcess('mi_chat')     p.start()     print('主进程')     print(os.getpid()) 

僵尸进程与孤儿进程

僵尸进程

主进程默认需要等待子进程结束才会结束，所有的子进程在运行结束之后都会变成僵尸进程
僵尸进程保留着pid和一些运行过程记录方便主进程查看，这些信息会被主进程回收

孤儿进程

子进程存活着,父进程意外死亡，子进程会被操作系统自动接管

守护进程

from multiprocessing import Process import time   def task(process_name):     print(f'子进程:{process_name}运行')     time.sleep(2)     print(f'子进程:{process_name}结束运行')   if __name__ == '__main__':     p = Process(target=task, args=('qq_zone',))     p.daemon = True     p.start()     print('process qq is over') 

互斥锁