Practice from Operating System with detailed solutions and model answers from past Tribhuvan University exams.
Define the term semaphore. How does semaphore help in dining philosopher problem?
Suppose a new process in a system arrives at an average of six processes per minute and each such process requires an average of 8 seconds of service time. Estimate the fraction of time the CPU is busy in a system with a single processor.
Write CPU scheduling criteria. For the processes listed in following table, draw Gantt chart illustrating their execution and calculate average waiting time and turnaround time using:
a) First Come First Serve
b) Shortest Remaining Time Next
c) Priority
d) Round Robin (quantum = 1 sec.)
| Process | Arrival Time (sec) | Burst Time (sec) | Priority |
|---|---|---|---|
| P0 | 0.00 | 3 | 7 |
| P1 | 2.01 | 2 | 7 |
| P2 | 3.01 | 2 | 2 |
| P3 | 3.02 | 3 | 2 |
| P4 | 7.00 | 1 | 4 |
What is role of scheduler in operating system? Differentiate between short-term and long-term Scheduler.
How can we solve producer-consumer problem using semaphore?
What is PCB? What are different information that are included in a PCB?
What is critical section problem? How semaphores can be used to solve critical section problem Also explain producer consumer problem with its solution using Mutex.