锁-lock

锁-lock

import time
from multiprocessing import Lock,Process
def func(i,lock):
    lock.acquire()   # 拿钥匙
    print('被锁起来的代码%s'%i)
    lock.release()  # 还钥匙
    time.sleep(1)

def func1 (i ,lock):
    lock.acquire()
    print('被锁起来的代码%s'%i)
    lock.release()
    time.sleep(1)
if __name__ == '__main__':
    lock = Lock()
    for i in range(10):
        p = Process(target=func1,args= (i,lock))
        p.start()

import time
from multiprocessing import Lock,Process
def func(i,lock):
    lock.acquire()   # 拿钥匙
    print('被锁起来的代码%s'%i)
    lock.release()  # 还钥匙
    time.sleep(1)

def func1 (i ,lock):
    with lock:      
# 代替acquire和release 并且在此基础上做一些异常处理,保证即便一个进程的代码出错退出了,也会归还钥匙
        print('被锁起来的代码%s'%i)
    time.sleep(1)
if __name__ == '__main__':
    lock = Lock()
    for i in range(10):
        p = Process(target=func1,args= (i,lock))
        p.start()

抢票的例子：

import json
import time
from multiprocessing import Process,Lock

def search(i):
    with open('ticket',encoding='utf-8') as f:
        ticket = json.load(f)
    print('%s :当前的余票是%s张'%(i,ticket['count']))

def buy_ticket(i):
    with open('ticket',encoding='utf-8') as f:
        ticket = json.load(f)
    if ticket['count']>0:
        ticket['count'] -= 1
        print('%s买到票了'%i)
    time.sleep(0.1)
    with open('ticket', mode='w',encoding='utf-8') as f:
        json.dump(ticket,f)

def get_ticket(i,lock):
    search(i)
    with lock:   # 代替acquire和release 并且在此基础上做一些异常处理,保证即便一个进程的代码出错退出了,也会归还钥匙
        buy_ticket(i)


if __name__ == '__main__':
    lock = Lock()     # 互斥锁
    for i in range(10):
        Process(target=get_ticket,args=(i,lock)).start()