调用结构体记录学生信息，可以人工输入学生信息并选择永久保存成文件形式，提供参考-Call structure record student information, student information can be entered manually and choose to permanently saved in the form of a file, and provide a reference

unix课程实验2，同步与异步write的效率比较，将文件读入缓存，调用times函数进行计时，进行写操作，写操作完全完成后再次调用times函数，记录结束的时间，再将不同时间输出-unix course experiment 2, synchronous and asynchronous write the efficiency comparison, the file is read into the cache, timing of times a function is called,

empty this now, so we can correctly record any inval calls that might be made during the draw call. -empty this now, so we can correctly record any inval calls that might be made during the draw call.