HAND IN Answers recorded on exam paper Student Number (digits) Student Number (words) To be sure your student number is legible, please write it as digits (9876543) and as words (nine eight seven six five four three) Queen's University, Faculty of Arts and Science, School of Computing Final Examination for CISC 324 and CMPE 324 April 13, 2015 D. Blostein Instructions from Professor Blostein This examination is 3 hours in length. No aids are allowed. Answer all questions in the space provided on this exam question paper. There are 2 extra pages at the end of the exam if you need more space to answer questions. Please write neatly. Illegible work will not be marked. There are a total of [100] points on this exam. Budget your time accordingly: the time limit of 180 minutes gives you 18 minutes to answer a 10 point question. Page 2 [22] points Page 3 [18] points Page 4 [20] points Page 5 [20] points Page 6 [20] points I cannot answer questions during the exam. If you find an exam question unclear, then make reasonable assumptions, write down those assumptions, and answer the question. Instructions from Queen's University PLEASE NOTE: Proctors are unable to respond to queries about the interpretation of exam questions. Do your best to answer exam questions as written. This material is copyrighted and is for the sole use of students registered in CISC/CMPE 324 and writing this exam. This material shall not be distributed or disseminated. Failure to abide by these conditions is a breach of copyright and may also constitute a breach of academic integrity under the University Senate's Academic Integrity Policy Statement.
Student Number Page 2 of 8 [8] 1. Define critical section. Explain how a monitor helps with the implementation of critical sections. Illustrate with an example of how you used monitors in Lab 5/6. Circle an answer and write a justification that shows you know the meaning of interrupt handler and process. [8] 2. The kernel of an operating system (a) is a process (c) is a cache (d) none of the above (b) is an interrupt handler [6] 3. Explain the motivation for LRU (Least Recently Used) page replacement: why is LRU expected to outperform FIFO page replacement?
Student Number Page 3 of 8 [10] 4. (a) Address localization: describe three reasons why a process that accesses virtual memory address L is likely to access L or a nearby address in the near future. (b) The most significant bits of a virtual memory address are the page number: page offset . Why is this convention used, rather than offset page ? Relate your answer to the address localization in (a). Circle an answer and write a justification that shows you understand SJN, turnaround time, response time, and throughput. [8] 5. The SJN (Shortest Job Next) CPU scheduling algorithm is optimal in the following sense: (a) it minimizes the average turnaround time (b) it minimizes the average response time (c) it minimizes the computation needed