python-day33--互斥锁

Posted 2020-10-04

锁的意思就是：一个一个的执行

 1 from multiprocessing import Process,Lock
 2 import os
 3 import time
 4 def work(mutex):
 5     mutex.acquire()
 6     print(‘task[%s] 上厕所‘ %os.getpid())
 7     time.sleep(3)
 8     print(‘task[%s] 上完厕所‘ %os.getpid())
 9     mutex.release()
10 
11 if __name__ == ‘__main__‘:
12     mutex=Lock()
13     p1=Process(target=work,args=(mutex,))
14     p2=Process(target=work,args=(mutex,))
15     p3=Process(target=work,args=(mutex,))
16     p1.start()
17     p2.start()
18     p3.start()
19 
20     print(‘主‘)

互斥锁

 1 from multiprocessing import Process,Lock
 2 import json
 3 import time
 4 import random
 5 import os
 6 def search():
 7     dic=json.load(open(‘a‘,))
 8     print(‘剩余票数%s‘ %dic[‘count‘])
 9 
10 def get_ticket():
11     dic=json.load(open(‘a‘,))
12     if dic[‘count‘] > 0:
13         dic[‘count‘]-=1
14         json.dump(dic,open(‘a‘,‘w‘))
15         print(‘%s 购票成功‘ %os.getpid())
16 def task(mutex):
17     search()
18     time.sleep(random.randint(1, 3)) #模拟购票一系列繁琐的过程所花费的时间
19     mutex.acquire()
20     get_ticket()
21     mutex.release()
22 if __name__ == ‘__main__‘:
23     mutex=Lock()
24     for i in range(50):
25         p=Process(target=task,args=(mutex,))
26         p.start()

模拟抢票