A2- Potokar, Charles

IST 341/IST 606 Management of Business Networks Assignment 2 Due Date: February 18, 2024, Midnight Chapter 4: 1. Five jobs arrive nearly simultaneously for processing and their estimated CPU cycles are, respectively: Job A = 2 ms, Job B = 12 ms, Job C = 15 ms, Job D = 7 ms, and Job E = 3 ms. a. Using FCFS, in what order would they be processed? What is the total time required to process all five jobs? What is the average turnaround time for each of these five jobs? b. Using SJN, and assuming that all jobs are present when the algorithm begins, in what order would they be processed? What is the total time required to process all five jobs? What is the average turnaround time for all five jobs? c. Using SJN, and assuming that all jobs are present when the algorithm begins, what is the average turnaround time for all five jobs using these speeds: Job A = 12 ms, Job B = 2 ms, Job C = 15 ms, Job D = 7 ms, and Job E = 3 ms. a) FCFS: Job A: 2 ms → Job B: 12 ms → Job C: 15 ms → Job D: 7 ms → Job E: 3 ms Time required = 2 + 12 + 15 + 7 + 3 = 39 ms Turnaround time: Job A = 2 ms Job B = 2 + 12 = 14 ms Job C = 2 + 12 + 15 = 29 ms Job D = 2 + 12 + 15 + 7 = 36 ms Job E = 2 + 12 + 15 + 7 + 3 = 39 ms b) SJN: When it comes to processing sequence, the shortest work is processed first. Job A: 2 ms → Job E: 3 ms → Job D: 7 ms → Job B: 12 ms → Job C: 15 ms Time required = 2 + 3 + 7 + 12 + 15 = 39 ms Turnaround time: Job A = 2 ms Job E = 2 + 3 = 5 ms Job D = 2 + 3 + 5 + 7 = 17 ms Job B = 2 + 3 + 5 + 7 + 12 = 29 ms Job C = 2 + 3 + 5 + 7 + 12 + 15 = 44 ms c) SJN: Job E: 3 ms → Job A: 12 ms → Job D: 7 ms → Job C: 15 ms Time required:  39 ms Turnaround time: Job E = 3 ms Job A = 3 + 12 = 15 ms Job D = 3 + 12 + 7 = 22 ms Job C = 3 + 12 + 7 + 15 = 37 ms 2. Given the following information: Job Arrival Time CPU Cycle A 0 15 B 2 2

C 3 14 D 6 10 E 10 2 Calculate which jobs will have arrived ready for processing by the time the first job is finished or is first interrupted. Do your calculation using each of the following scheduling algorithms. a.       FCFS: Remaining 4 processes b.     SJN: Remaining 4 processes c.       SRT: Only process B d.     Round Robin: Processes B and C 3. Using the same information from the previous exercise, calculate the start time and finish time for each of the five jobs using each of the following scheduling algorithms. a.  FCFS: Start/Finish Times:  A: 0 - 15  B: 15 - 17  C: 17 - 31  D: 31 - 41  E: 41 - 43 b. SJN: Start/Finish Times:  A: 0 - 15  B: 15 - 17  C: 29 - 34  D: 19 - 29  E: 17 - 19 c.   SRT: Start/Finish Times:  A: 0 - 29  B: 2 - 4  C: 29 - 43  D: 6 - 18  E: 10 - 12 d. Round robin: Start/Finish Times:  A: 0 - 5, 15 - 20, 30 - 35  B: 5 - 10, 20 - 22  C: 10 - 15, 35 - 43  D: 22 - 27  E: 27 - 30 4. Using the same information given for the previous exercise, compute the turnaround time for every job using each of the following scheduling algorithms (ignoring context switching overhead times). 5. a.   FCFS: A: 15, B: 15, C: 28, D: 35, E: 33 6. b. SJN: B: 2, E: 4, A: 19, C: 30, D: 37 7. c.   SRT: B: 2, E: 4, A: 15, C: 29, D: 39 8. d. Round robin: A: 43, B: 22, C: 33, D: 27, E: 30 Chapter 5: 9. Given the ice cream example from the beginning of this chapter, identify the four necessary conditions for deadlock and explain whether each one is present, or is not present, in this case.