4,5 04 互斥锁 抢票程序

# 互斥锁/进程锁/同步锁
# import json
import time
from multiprocessing import Process,Lock

def show_t(i):

    with open('ticket','r',encoding='utf-8') as f:
        ticket_data = f.read()
    # print(ticket_data)
    t_data = eval(ticket_data)
    # print(t_data,type(t_data))
    print('%s查询剩余票数为%s'%(i,t_data['count']))

def get_t(i,l1):
    l1.acquire()
    with open('ticket', 'r', encoding='utf-8') as f:
        ticket_data = f.read()
        # print(ticket_data)
    t_data = eval(ticket_data)
    # print(t_data,type(t_data))
    # print('%s查询剩余票数为%s' % (i, t_data['count']))
    if t_data['count'] > 0:
        t_data['count'] -= 1
        print('%s抢票成功'%i)
        time.sleep(0.2)
        with open('ticket', 'w') as f:
            f.write(str(t_data))

    else:
        print('没票了!!!')
    l1.release()

if __name__ == '__main__':
    l1 = Lock()
    for i in range(10):
        p1 = Process(target=show_t,args=(i,))
        p1.start()
    for i in range(10):
        p2 = Process(target=get_t,args=(i,l1) )
        p2.start()





# import time
#
# def f1(i,lic):
#     lic.acquire()
#     time.sleep(1)
#     print(i)
#     lic.release()
#
# if __name__ == '__main__':
#     lic = Lock()
#     for i in range(20):
#         p = Process(target=f1, args=(i,lic))
#         p.start()