nachos实验 操作系统实验 管程同步机制 消费者和生产者为例 改编原先版本中的一点小错误-nachos experimental test tube process operating system, consumers and producers as an example synchronization mechanism adapted the original version of a small error

自动售卖机，当成功售出货品后，会有提示信息；当消费者投币大于货品价值，会有找零提示信息。-Vending machines When goods sold successfully, there will be message consumer coin is greater than the value of the goods, there will be change for the message.