Answer Happy

6. (a) In a modern multitasking operating system, what are the main goals (list at least four goals) of process scheduling algorithms? (4 marks) (b) Briefly explain the concepts of non-preemptive and preemptive scheduling algorithms - focus on their difference. (4 marks) (c) Three jobs A, B, and Carrive at different times. Their arriving time, estimated running time and job priority, are listed in the following table. Job Arriving time (second) Priority Estimated running time (second) 16 8 4 A B с 0 1 2 1 3 2 Note: 3 indicates the highest priority and 1 the lowest Calculate the average turnaround time and average waiting time when applying each of the following scheduling algorithms. (1) Priority scheduling (ii) First-come, first-served (iii) Round robin For (i) and (iii), assume scheduling quanta of 2 seconds. For (ii), assume that only one job at a time runs until it finishes. (12 marks)