Q1. List all the five services given by an operating system. Describe how each gives convenience to the users. Describe as well in which cases it would be not possible for user-level programs to provide such services.

Q2. What do you mean by interrupts? describe how are they handled by using the operating system? Describe.

Q3. Illustrate the differences among the short-term, medium-term and long-term scheduling.

Q4. Consider the given set of processes, with the length of CPU-burst time given in the milliseconds:

Process     Burst Time     Priority
A                 10                 3
B                  1                  1
C                  2                  3
D                  1                  4
E                   5                  2

The processes are supposed to have arrived in the order A, B, C, D, E, all at time 0.

a) Draw four Gantt charts describing the execution of these processes by using FCFS, SJF, a non-preemptive priority (a smaller priority number implies higher priority), and RR (quantum = 1) scheduling.

b) Illustrate the turnaround time of each process for each of the scheduling algorithms in part (a)?

c) Illustrate the waiting time of each process for each of the scheduling algorithms in part (a)?

Q5. What do you mean by critical-section problem? Illustrate the three requirements which consists of a solution to the critical-section problem should satisfy?