CMSC421 Sample Exam
Name: _____________________________________
Last four of SSN: _____________________________

Instructions:
Your have 70 minutes to do this test.
Cheating will not be tolerated and you will fail the test.
Talking with anyone but the instructor is cheating.
This is a closed book exam. There should be nothing but this exam and your writing utensils on your desk. When you are finished with this test, very quietly collect up your possessions, turn in the test and leave the room. Keep this room quiet at all times.

1. Early OSs had the notion of a "monitor" mode of operation. What is this mode, and how does it help with security?
2. What are the five major activities of an operating system in regard to process management?
3. Define the difference between preemptive and nonpreemptive scheduling.
4. What is the meaning of busy waiting? How else can the Operating system make a process "wait" in a manner more effective than busy waiting?
5. Describe the four necessary conditions for deadlock to occur. Present a technique that eliminates the "hold and wait" condition, thus avoiding deadlock.

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