(1)Suppose a non-preemptive scheduler uses variable priorities
and time quanta as the following table,where the highest priority is 5
Priority Time quantum New priority after New priority after
time quantum is expired returning from I/O
5 40 4 5
4 60 3 5
3 100 2 4
2 200 1 4
1 320 1 3
Which of the following statements is "incorrect"?
(A)Response time of interactive threads will increase.
(B)Priorities of CPU-intensive threads will be lowered.
(C)Time-quanta of I/O-bound threads will decrease.
(D)None of the above.
我的想法是Response time是第一次回应时间 所以RR的Quantum就是Response time
但优先权2和1的Process变为同样优先权所以A是错的
B的话CPU就是和I/O的优先权值相反 这样对吗?
C的话我就不知道要看哪一个了
(2)另外我想知道有没有开放式课程是讲同步问题的MAILBOX
有点不是很清楚Blocking receive , Non-Blocking receive之类system call的用法
还有分类题库有看到的serializable transaction问题洪逸好像也没教过
不知道有没有网页讲的比较清楚的呢
谢谢各位拨空看我的问题
希望可以获得解答^^