python-day33--互斥锁

锁的意思就是：一个一个的执行

 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')

互斥锁

 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()

模拟抢票