今天用面向对象写了一段代码,用创建的类重构父类的方法,实现函数锁能实现的功能:代码如下
1 from os import getpid 2 from time import sleep 3 from multiprocessing import Process 4 5 6 class MyProcess(Process): 7 8 def __init__(self, args): 9 super(MyProcess, self).__init__() 10 self.args = args 11 12 def run(self): 13 print('Process ID is %s' % getpid()) 14 print('Process %s has been executed ' % self.args) 15 16 def start(self): 17 print('Process %s will be executed ' % self.args) 18 super().start() 19 20 def terminate(self): 21 super().terminate() 22 23 def join(self, timeout=None): 24 super().join() 25 26 def is_alive(self): 27 super().is_alive() 28 29 30 if __name__ == '__main__': 31 process_list = [] 32 for i in range(10): 33 p = MyProcess(i) 34 p.start() 35 print(p.is_alive()) 36 process_list.append(p) 37 for p in process_list: 38 print(p.is_alive()) 39 print('There will terminated process %s' % p) 40 p.terminate() 41 sleep(0.2) # 这里不延时0.2而直接打印的话,下边的is_alive会显示True 42 print(p.is_alive()) 43 p.join() 44 print(p.is_alive())
这段代码的执行结果是:
1 Process 0 will be executed 2 None 3 Process 1 will be executed 4 None 5 Process 2 will be executed 6 None 7 Process 3 will be executed 8 None 9 Process 4 will be executed 10 None 11 Process 5 will be executed 12 None 13 Process 6 will be executed 14 None 15 Process 7 will be executed 16 None 17 Process 8 will be executed 18 None 19 Process 9 will be executed 20 None 21 None 22 There will terminated process <MyProcess(MyProcess-1, started)> 23 None 24 None 25 None 26 There will terminated process <MyProcess(MyProcess-2, started)> 27 Process ID is 14232 28 Process 3 has been executed 29 None 30 None 31 None 32 There will terminated process <MyProcess(MyProcess-3, started)> 33 Process ID is 13276 34 Process 5 has been executed 35 Process ID is 11380 36 Process 4 has been executed 37 None 38 None 39 None 40 There will terminated process <MyProcess(MyProcess-4, stopped)> 41 Process ID is 13616 42 Process 6 has been executed 43 Process ID is 13880 44 Process 7 has been executed 45 Process ID is 9628 46 Process 8 has been executed 47 Process ID is 13052 48 Process 9 has been executed 49 None 50 None 51 None 52 There will terminated process <MyProcess(MyProcess-5, stopped)> 53 None 54 None 55 None 56 There will terminated process <MyProcess(MyProcess-6, stopped)> 57 None 58 None 59 None 60 There will terminated process <MyProcess(MyProcess-7, stopped)> 61 None 62 None 63 None 64 There will terminated process <MyProcess(MyProcess-8, stopped)> 65 None 66 None 67 None 68 There will terminated process <MyProcess(MyProcess-9, stopped)> 69 None 70 None 71 None 72 There will terminated process <MyProcess(MyProcess-10, stopped)> 73 None 74 None
发现判断一个进进程是否还在运行后发现打印的全是None,看Process的源码:
1 def is_alive(self): return False
发现有返回值.
而自己在这里的想法是直接用super方法调用父类方法后,会执行后返回一个结果,但是这里的使用super()方法后,会是自己重构的方法具有父类的属性,需要一个变量去接,如果需要的话可以返回这个值
如果没有返回值的话,就直接调用父类的方法
修改后的代码如下:
1 from os import getpid 2 from time import sleep 3 from multiprocessing import Process 4 5 6 class MyProcess(Process): 7 8 def __init__(self, args): 9 super(MyProcess, self).__init__() 10 self.args = args 11 12 def run(self): 13 print('Process ID is %s' % getpid()) 14 print('Process %s has been executed ' % self.args) 15 16 def start(self): 17 print('Process %s will be executed ' % self.args) 18 super().start() 19 20 def terminate(self): 21 super().terminate() 22 23 def join(self, timeout=None): 24 super().join() 25 26 def is_alive(self): 27 try: 28 result = super().is_alive() 29 return result 30 except: 31 print("Something was wrong!") 32 33 34 if __name__ == '__main__': 35 process_list = [] 36 for i in range(10): 37 p = MyProcess(i) 38 p.start() 39 print(p.is_alive()) 40 process_list.append(p) 41 for p in process_list: 42 print(p.is_alive()) 43 print('There will terminated process %s' % p) 44 p.terminate() 45 sleep(0.2) # 这里不延时0.2而直接打印的话,下边的is_alive会显示True 46 print(p.is_alive()) 47 p.join() 48 print(p.is_alive())