版权音乐助手11.11促销活动

# 示例：处理促销活动的库存管理
import threading

class Promotion:
    def __init__(self, product_id, original_price, discount, stock):
        self.product_id = product_id
        self.original_price = original_price
        self.discount = discount
        self.stock = stock
        self.lock = threading.Lock()

    def apply_discount(self):
        return self.original_price * (1 - self.discount)

    def purchase(self, quantity):
        with self.lock:
            if self.stock >= quantity:
                self.stock -= quantity
                return True
            else:
                return False

# 创建一个促销实例
promotion = Promotion(product_id=1, original_price=100, discount=0.2, stock=100)

# 用户购买操作
if promotion.purchase(quantity=2):
    print("购买成功！当前库存:", promotion.stock)
else:
    print("库存不足，购买失败！")