from multiprocessing import Process,Lock

 import os

 import time

 def work(mutex):

     mutex.acquire()

     print('task[%s] 上厕所' %os.getpid())

     time.sleep(3)

     print('task[%s] 上完厕所' %os.getpid())

     mutex.release()

 if __name__ == '__main__':

     mutex=Lock()

     p1=Process(target=work,args=(mutex,))

     p2=Process(target=work,args=(mutex,))

     p3=Process(target=work,args=(mutex,))

     p1.start()

     p2.start()

     p3.start()

     print('主')

 from multiprocessing import Process,Lock

 import json

 import time

 import random

 import os

 def search():

     dic=json.load(open('a',))

     print('剩余票数%s' %dic['count'])

 def get_ticket():

     dic=json.load(open('a',))

     if dic['count'] > 0:

         dic['count']-=1

         json.dump(dic,open('a','w'))

         print('%s 购票成功' %os.getpid())

 def task(mutex):

     search()

     time.sleep(random.randint(1, 3)) #模拟购票一系列繁琐的过程所花费的时间

     mutex.acquire()

     get_ticket()

     mutex.release()

 if __name__ == '__main__':

     mutex=Lock()

     for i in range(50):

         p=Process(target=task,args=(mutex,))

         p.start()