本次实验的目的在于将nachos中的锁机制和条件变量的实现补充完整，并利用这些同步机制实现几个基础工具类。实验内容分三部分：实现锁机制和条件变量，并利用这些同步机制将实验一中所实现双向有序链表类修改成线程安全的；实现一个线程安全的表结构；实现一个大小受限的缓冲区（详细内容请看nachos-labs.pdf）。-the purpose of the experiment is to the nachos lock mechanism and conditions for the realization of supplementary variables integrity, Using these synchronization mechanism based tool for achieving several categories. Experiment three parts : achieving lock mechanism and variable conditions, Using these experimental synchronization mechanism as a bidirectional orderly objectlist revise the security thread; the realization of a security thread table structure; the realization of a limited size of the buffer zone (for details, please see nachos - labs.pdf).