Programming Assignment HW5: CPU Scheduling draft v04/02/18 4 PM Deadline April 7th, 2018, 5 PM. Late deadline with penalty April 9th, 2018, 5 PM

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1 Programming Assignment HW5: CPU Scheduling draft v04/02/18 4 PM Deadline April 7th, 2018, 5 PM. Late deadline with penalty April 9th, 2018, 5 PM Purpose: The objective of this assignment is to become familiar with some of the CPU scheduling algorithms. You will be implementing multiple scheduling algorithms while tracking measures of scheduling effectiveness. Description of assignment: In this assignment you will be implementing basic CPU scheduling algorithms specified below. The first command line argument specifies the seed used to (pseudo)randomly generate arrival times and burst times. The next two command line arguments specify the number of processes, and the time quantum (for round-robin). This assignment specifies one case where you need to support preemption of processes. Implementing the following four CPU scheduling algorithms using C programming language. Assume that that all jobs are CPU bound (i.e. they do not block for I/O), and the context-switching time is negligible. Also assume that in Round Robin if a new processes arrives the same instant when a process is switched out, the new process gets in the ready queue first. In Preemptive SJF, there is no preemption if an arriving job offers the same remaining time as the process currently running. First Come First Serve (FCFS) [Non-preemptive] Round Robin (RR) with the specified quantum [Non-preemptive] Shortest Job First (SJF). Implement both o Non-preemptive o Preemptive (also termed shortest remaining time first) You must produce a Gantt for each scheduling algorithm to help visualize the sequence of execution for each process (See example output given below). You will analyze the performance of these scheduling algorithms by tracking the turnaround time, the waiting time and the throughput for each process and printing the average turnaround time after all processes have completed. The turnaround time for a process is the difference between a job s submission and completion times. The average turnaround time reports the average for the set of processes that were scheduled. The waiting time for a process reflects the total amount of time spent by that process in the ready queue. The average waiting time reports the average for the set of processes that were scheduled. Page 1 of 6

2 The throughput for a scheduling algorithm measures the total number of tasks processes per unit of time. Requirements of Task 1. Your program must accept three arguments from the command line. The first argument is the seed. The seed is used to initialize the random number generator (similar to assignment 1), which is used to generate two random numbers: Arrival time and the Burst time.. Using the seed initialize the random number generator then for each process generate an arrival time and a burst time. The arrival time of a process must be in the range [0-49] and the burst time of a process must be in the range [1-10], so you must map the random numbers generated into these ranges as needed. A Pseudo-code for using the random number generator to generate arrival times and burst times is given below. The second argument is the number of processes to be generated. The third argument is the time quantum to be used for Round Robin scheduling. See the example below. Pseudo code for generating arrival and burst times: srand(seed) // initialize random number for( each process i in range 0 to number of processes -1) { arrivaltime[i] = rand() % 50 // generate arrival time in range [0-49] bursttime[i] = rand() %10 +1 // generate burst time in range [1-10] } Sort and name the processes in the order of arrival. Thus the first one to arrive is P1, the second to arrive is P2 and so on. If any processes arrive at the same time, arbitrarily order them in any order. 2. Your program (scheduler.c) should be able to correctly perform FCFS, RR, SJF (nonpreemptive), and SJF (preemptive) given a set of processes and an arrival time and burst time for each process. 3. Implement FCFS (non-preemptive) and print a Gantt chart showing the execution sequence. Report average values for turnaround time and waiting time, and the overall throughput. 4. Implement RR (non-preemptive) and print a Gantt chart showing the execution sequence. Report average values for turnaround time and waiting time, and the overall throughput. For this part use the quantum specified in the argument list. 5. Implement SJF (non-preemptive) and print a Gantt chart showing the execution sequence. Report average values for turnaround time and waiting time, and the overall throughput. Page 2 of 6

3 6. Implement SJF (preemptive) and print a Gantt chart showing the execution sequence. Report average values for turnaround time and waiting time, and the overall throughput. Example Output (note that random number generation may be machine dependent): machine$./scheduler /Scheduler Arrival Time Burst Time After Sorting by Arrival times Arrival Time Burst Time P P P P P In First Come First Serve [22]-- P 3 -- [29] [29]-- P 4 -- [30] Average Turnaround time for First Come First Serve is Average Wait time For First Come First Serve is Average Throughput For First Come First Serve is In Round Robin Page 3 of 6

4 [22]-- P 3 -- [26] [26]-- P 4 -- [27] [27]-- P 3 -- [30] Average Turnaround time For Round Robin is Average Wait time For Round Robin is Average Throughput For Round Robin is In Shortest Job First - Non Preemptive [22]-- P 3 -- [29] [29]-- P 4 -- [30] Average Turnaround time for Shortest Job First - Non Preemptive is Average Wait time Shortest Job First - Non Preemptive is Average Throughput For Shortest Job First - Non Preemptive is In Shortest Job First - Preemptive [22]-- P 3 -- [25] [25]-- P 4 -- [26] [26]-- P 3 -- [30] Average Turnaround time for Shortest Job First - Preemptive is Average Wait time For Shortest Job First - Preemptive is Average Throughput For Shortest Job First - Preemptive is Page 4 of 6

5 Command line arguments for grading: >./scheduler <seed> <number of processes> <time quantum> The seed argument is an integer used to initialize the seed for the random number generator. The number of processes argument is an integer which specifies the number of processes. The time quantum argument is an integer (time units) to be used by the Round Robin scheduling. What to Submit Submit a single.zip or.tar file on Canvas. The.zip or.tar file should contain the following: All.c and.h files related to the assignment (please document your code), A Makefile that performs both a make clean as well as a make all, A README.txt file containing a description of each file and any information you feel the grader needs to grade your program. Submit the.zip/.tar file using canvas. You submitted files should not include any directory structure. Your code must be executable on the machines in the 120 lab. Filename Convention: You can name your.c and.h files anything you want. However, the archive file should be named as <LastName>_<FirstName>_HW5.<tar/zip>. E.g. if you are John Doe and submitting for HW5, then the zip file should be named Doe_John_HW5.zip. Grading This assignment is worth 100 points. Points are allocated in the following way: 20pts correctly implementing FCFS scheduling algorithm 5pts producing the correct Gantt chart 5pts getting average turnaround time 5pts getting average wait time 5pts getting throughput 20pts correctly implementing RR scheduling algorithm 5pts producing the correct Gantt chart 5pts getting average turnaround time 5pts getting average wait time 5pts getting throughput 20pts correctly implementing SJF [non-preemptive] scheduling algorithm 5pts producing the correct Gantt chart 5pts getting average turnaround time 5pts getting average wait time 5pts getting throughput 20pts correctly implementing SJF [preemptive] scheduling algorithm 5pts producing the correct Gantt chart Page 5 of 6

6 5pts getting average turnaround time 5pts getting average wait time 5pts getting throughput 5pts submitting a makefile that performs make clean and make all 5pts compilation without warnings or errors 5pts suitable documentation of code in the code files 5pts suitable documentation of code in README file Note: You are required to work alone on this assignment. You may not use any code not written by yourself personally. Late Policy Click here for the class policy on submitting late assignments. Revisions: This assignment document may be modified to clarify any questions (and the version number incremented), but the crux of the assignment will not change. 3/26/18 9 PM Replaced example output 4/2/2013 In Shortest Job First - Non Preemptive P5 s completion time is 52. Page 6 of 6