lab 1: 100/100
details：https://ipads.se.sjtu.edu.cn/courses/cse/labs/lab1.html
lab 2: 100/100
details：https://ipads.se.sjtu.edu.cn/courses/cse/labs/lab2.html
lab 3: 95/100 (Part 4-Snapshot is not implemented, while other functions are perfectly well)
details：https://ipads.se.sjtu.edu.cn/courses/cse/labs/lab3.html
lab 4: 100/100 (Deadlock Prevention is achieved, but current testcases cannot detect that. So you need to add additional cases.)
details：https://ipads.se.sjtu.edu.cn/courses/cse/labs/lab4.html