BCA Semester 4 – Operating System – Unit 3: Process Management (15Hrs.)

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.)

What is CPU scheduling? Write down the criteria for CPU scheduling? Consider the following set of processes, with the length of the CPU burst given in milliseconds, draw Gantt chart illustrating their execution and calculate average waiting time and turnaround time using:a) First Come First Serveb) Shortest Job Firstc) Non-preemptive priority (smaller number implies higher priority)d) Round Robin (quantum = 1)

What is role of scheduler in operating system? Differentiate between short-term and long-term Scheduler.

What do you mean by Race condition? Consider two concurrently running process PI with statement S1 and P2 with statement S2. Suppose we require that S2 be executed only after S1 has completed. For this synchronization need, write a semaphore solution.

What are CPU scheduling criteria's? Consider below table of four processes under multi-level queue scheduling. Queue number denotes queue of the process. Priority of queue 1 is greater than queue 2. Queue 1 use Round Robin with time quantum t=2ms and queue 2 use FCFS. Draw Gantt chart to illustrate their execution and calculate average waiting and turnaround time also.

How can we solve producer-consumer problem using semaphore?

The processes are assumed to have arrived in the order $p1, p2, p3, p4, p5$ all at time 0. Draw a Gantt chart illustrating their execution and calculate average waiting time and turnaround time for the process given below using:
a) First Come First Serve
b) Shortest Remaining Time Next
c) Priority Schedulingd) Round Robin (quantum = 2)

Write short notes on (Any Two):
a) Access Control Matrix
b) Process States
c) Kernel

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.