import multiprocessing
import time
a = 1

def add_a1():
    # print("这里是进程:", i)
    time.sleep(3)
    global a
    for i in range(10000000):
        a += i
    print(a)

def write_to_file():
    f = open("data.txt","w")
    f.write("1111")
    f.write("1111")
    f.write("1111")
    f.write("1111")
    f.write("1111")
    f.write("1111")
    f.write("1111")
    f.write("1111")
    f.write("1111")
    f.close()

if __name__ == '__main__':
    for i in range(5):
        m = multiprocessing.Process(target=add_a1) # 多进程
        m.start()
        print(m.pid)
    # print(multiprocessing.active_children())
    while multiprocessing.active_children() != []:
        pass
    print("stop")