线程共享安全问题

数据的存储跟线程无关；一个进程中的数据在多个线程中可以直接用

list1 = [1, 2, 3]


def func1():
    list1.append(100)
    global list2
    list2 = [4,5,6]


def func2():
    list1[0] = 'hello'
    print(list2)   # [4, 5, 6]


t1 = Thread(target=func1())
t2 = Thread(target=func2())

t1.start()
t2.start()
print(list1)   # ['hello', 2, 3, 100]

当多线程同时处理一个数据时，数据可能会产生问题；
所以引入Lock

步骤：
获取锁对象
获取数据
数操作完成后
释放锁对象

注意：使用锁的时候保证一个数据对应一把锁
"""

class Account:
    def __init__(self, name, tel, balance, bank='招商银行'):
        self.bank = bank
        self.card_number = '392222222293093'
        self.name = name
        self.tel = tel
        self.balance = balance
        # 1.创建锁
        self.lock = Lock()

    def save_money(self, amount):
        print('========开始存钱========')
        # 2.使用锁
        self.lock.acquire()
        # 获取余额
        bl = self.balance
        print('余额：', bl)
        sleep(3)
        self.balance = bl + amount
        # 3.释放锁
        self.lock.release()
        print('存钱余额：',self.balance)
        print('========存钱结束========')

    def draw_money(self,amount):
        print('=======开始取钱!=========')
        self.lock.acquire()
        bl = self.balance
        print('余额：',bl)
        if bl < amount:
            print('余额不足')
            print('======取钱结束=======')
            return
        sleep(4)
        self.balance = bl - amount
        self.lock.release()
        print('取钱余额：',self.balance)
        print('======取钱结束======')

account = Account('hjr','232442',10000)

t1 = Thread(target=account.save_money,args=(2000,))
t2 = Thread(target=account.draw_money,args=(5000,))

t1.start()
t2.start()
t1.join()
t2.join()
print(account.balance)