线程

官方：进程（Process）是计算机中的程序关于某数据集合上的一次运行活动，是系统进行资源分配和调度的基本单位，是操作系统结构的基础。在早期面向进程设计的计算机结构中，进程是程序的基本执行实体；在当代面向线程设计的计算机结构中，进程是线程的容器。程序是指令、数据及其组织形式的描述，进程是程序的实体。

格式：

    import multiprocessing   #使用进程对象之前要导入进程模块

    p=multiprocessing.Process(target=[函数],arges=(tuple))

    target 函数的名字

    arges 传入函数的参数，为tuple类型数据

常用对象

    is_alive()    #判断是否进程存活，返回bool类型数据

    run()         #启动进程

    start()       #启动进程，自动调用run()，此方法常用

    join(timeout)  #等待进程结束或进程超时

讯享网

    name       #进程名字

    pid           #进程名字

    terminate #结束进程

举例：

import multiprocessing import time def worker(arge,interval): print("进程{0}开始".format(arge)) time.sleep(interval) print("进程{0}结束".format(arge)) def main(): print("开始主进程") p1 = multiprocessing.Process(target=worker,args=(1,1)) p2 = multiprocessing.Process(target=worker,args=(2,1)) p3 = multiprocessing.Process(target=worker,args=(3,1)) p1.start() p2.start() p3.start() print("主进程结束") print("the number of cpu is: {0}".format(multiprocessing.cpu_count())) #查看cpu数目 for i in multiprocessing.active_children(): print("the active of child is :{0},进程id号:{1},process is alive:{2}".format(i.name,i.pid,i.is_alive())) #打印子进程名称、id号、存活状态 if __name__ == '__main__': main() 

结果：

讯享网开始主进程 主进程结束 the number of cpu is: 4 the active of child is :Process-1,进程id号:33600,process is alive:True the active of child is :Process-3,进程id号:34240,process is alive:True the active of child is :Process-2,进程id号:31216,process is alive:True 进程1开始 进程2开始 进程3开始 进程1结束 进程2结束 进程3结束 Process finished with exit code 0

lock组件

     lock组件

import multiprocessing import time def add1(lock, value, number): with lock: print("start add1 number = {0}".format(number)) for i in range(1, 5): number += value time.sleep(0.3) print("number = {0}".format(number)) def add3(lock, value, number): lock.acquire() print("start add3 number = {0}".format(number)) try: for i in range(1, 5): number += value time.sleep(0.3) print("number = {0}".format(number)) finally: lock.release() if __name__ == "__main__": lock = multiprocessing.Lock() number = 0 pw = multiprocessing.Process(target=add1, args=(lock, 1, number)) pa = multiprocessing.Process(target=add3, args=(lock, 3, number)) pw.start() pa.start() print("main process end.")

结果：

讯享网main process end. start add1 number = 0 number = 1 number = 2 number = 3 number = 4 start add3 number = 0 number = 3 number = 6 number = 9 number = 12 Process finished with exit code 0

共享内存

    不同进程彼此之间是互不通信，multiprocessing模块中存在Value和array对象，提供进程之间共享内存进行通信

举例：

import multiprocessing from multiprocessing import Value import time def add3(value,number): try: print("------开始+3进程------") for i in range(1,5): number.value+=value #3+3 print("number = {0}.".format(number.value)) except Exception as e: raise e def add1(value,number): try: print("------开始+1进程------") for i in range(1,5): number.value+=value #1+1 print("number = {0}.".format(number.value)) except Exception as e: raise e def main(): number = Value('d',0) p1=multiprocessing.Process(target=add1,args=(1,number)) p2=multiprocessing.Process(target=add3,args=(3,number)) p1.start() p2.start() if __name__ == '__main__': main()

结果：

讯享网------开始+3进程------ number = 3.0. number = 6.0. number = 9.0. number = 12.0. ------开始+1进程------ number = 13.0. number = 14.0. number = 15.0. number = 16.0. Process finished with exit code 0