Python--day37--进程锁

进程锁的示意图：

　　锁.py:

#锁
#火车票
import json
import time

from multiprocessing import Process
from multiprocessing import Lock

def show(i):
    with open('ticket') as f:
        dic = json.load(f)
    print('余票：%s'%dic['ticket'])

def buy_ticket(i,lock):
    lock.acquire()  #拿钥匙进门
    with open('ticket') as f:
        dic = json.load(f)
        time.sleep(0.1)
    if dic['ticket'] > 0:
        dic['ticket'] -= 1
        print('33[32m%s买到票了33[0m'%i)
    else:
        print('33[31m%s没买到票33[0m'%i)
    time.sleep(0.1)
    with open('ticket','w') as f:
        json.dump(dic,f)
    lock.release()  #还钥匙

if __name__ == '__main__':
    for i in range(10):
        p = Process(target=show, args=(i,))
        p.start()
    lock = Lock()
    for i in range(10):
        p = Process(target=buy_ticket, args=(i,lock))
        p.start()

运行结果：