1 Objectives This programming project is to simulate a few CPU scheduling policies discussed in the class. You will write a C/C++ program to implement a simulator with different scheduling algorithms. The simulator selects a task to run from ready queue based on the scheduling algorithm. Since the project intends to simulate a CPU scheduler, so it does not require any actual process creation or execution. When a task is scheduled, the simulator will simply print out what task is selected to run at a time. It outputs the way similar to Gantt chart style.

Description

The selected scheduling algorithms to implement in this project are 1) First Come First Serve (FCFS), 2) Round Robin (RR), and 3) Shortest Remaining Time First (SRTF). The detailed algorithms are already described in class slides and textbook Chapter 6.

2.1 Task Information The task information will be read from an input file. The format is pid arrival time burst time All of fields are integer type where pid is a unique numeric process ID arrival time is the time when the task arrives in the unit of milliseconds burst time the is the CPU time requested by a task, in the unit of milliseconds The time unit for arrival time, burst time and interval is millisecond

2.2 Command-line Usage and Examples Usage: proj2 input file [FCFS|RR|SRTF] [time quantum] where input file is the file name with task information. FCFS, RR, and SRTF are names of scheduling algorithms. The time quantum only applies to RR. FCFS is nonpreemptive, while RR and SRTF are all preemptive. The last argument is needed only for RR. (See following table for more examples)

Examples	Description
proj2 input.1 FCFS	FCFS scheduling with the data file input.1
proj2 input.1 RR 2	Simulate RR scheduling with time quantum 2 milliseconds (4th parameter is required even for quantum 1 millisecond) with the data file input.1
proj2 input.1 SRTF	Simulate SRTF scheduling with the data file input.1

3 Requirements The project requires to simulate FCFS, RR, and SRTF scheduling for given tasks and to compute the average waiting time, response time, turnaround time and overall CPU usage. You can find their definitions in textbook. 1. Implement scheduling algorithm for FCFS, RR, and SRTF. The program should schedule tasks and print progress of task every unit time (millisecond) as shown in sample outputs. 2. Print statistical information. As soon as all tasks are completed, the program should compute and print 1) average waiting time, 2) average response time, 3) average turnaround time and 4) overall CPU usage. Note: if you use static array to implement ready queue structure, you can assume the maximum queue length is 20.

4 Suggested Methodology 1. Implement one scheduling algorithm at each step 2. You can use circular linked list as a queue structure 3. You can use a data structure similar to PCB for each task, though it will be much simpler.

Below is the input file:

% more input.1 1 0 10 2 0 9 3 3 5 4 7 4 5 10 6 6 10 7 % proj2 Usage: proj2 input_file FCFS|RR|SRJF [quantum] % proj2 input.1 FCFS Schdeuling algorithm: FCFS Total 6 tasks are read from "input.1". press 'enter' to start... ================================================================== process 1 is running process 1 is running process 1 is running process 1 is running process 1 is running process 1 is running process 1 is running process 1 is running process 1 is running process 1 is running process 1 is finished....... process 2 is running process 2 is running process 2 is running process 2 is running process 2 is running process 2 is running process 2 is running process 2 is running process 2 is running process 2 is finished....... process 3 is running process 3 is running process 3 is running process 3 is running process 3 is running process 3 is finished....... process 4 is running process 4 is running process 4 is running process 4 is running process 4 is finished....... process 5 is running process 5 is running process 5 is running process 5 is running process 5 is running process 5 is running process 5 is finished....... process 6 is running process 6 is running process 6 is running process 6 is running process 6 is running process 6 is running process 6 is running process 6 is finished....... All processes finish .................... ============================================================ Avarage cpu usage : 100.00 % Avarage waiting time : 14.17 Avarage response time : 14.17 Avarage turnaround time: 21.00 ============================================================ % proj2 input.1 RR 2 Schdeuling algorithm: RR Total 6 tasks are read from "input.1". press 'enter' to start... ================================================================== process 1 is running process 1 is running process 2 is running process 2 is running process 1 is running process 1 is running process 3 is running process 3 is running process 2 is running process 2 is running process 1 is running process 1 is running process 4 is running process 4 is running process 3 is running process 3 is running process 5 is running process 5 is running process 6 is running process 6 is running process 2 is running process 2 is running process 1 is running process 1 is running process 4 is running process 4 is running process 4 is finished....... process 3 is running process 3 is finished....... process 5 is running process 5 is running process 6 is running process 6 is running process 2 is running process 2 is running process 1 is running process 1 is running process 1 is finished....... process 5 is running process 5 is running process 5 is finished....... process 6 is running process 6 is running process 2 is running process 2 is finished....... process 6 is running process 6 is finished....... All processes finish .................... ============================================================ Avarage cpu usage : 100.00 % Avarage waiting time : 22.50 Avarage response time : 4.00 Avarage turnaround time: 29.33 ============================================================ % proj2 input.1 SRTF Schdeuling algorithm: SRTF Total 6 tasks are read from "input.1". press 'enter' to start... ==================================================================