In this assignment, you will be writing a program that reads a list of process start times and durations from stdin. That list will be used four times to run through the following CPU scheduling algorithms:

First Come, First Served

Shortest Job First

Shortest Remaining Time First

Round Robin

Your program will show three statistics; the average process response time, the average process wait time, and the average process turnaround time for each scheduling algorithm. The time quantum for the Round Robin scheduler is 100ms. Your program only needs to work with a maximum of 100 processes.

Hints:

Don't overcomplicate this assignment. Keep your process start times in one integer array, your burst times in another integer array, and then refer to those processes via other arrays.

Make four functions, one for each scheduling mechanism. Pass the input data to each function as a parameter. Do not modify your original arrays as you will be reusing the data in those arrays multiple times.

This program is simply an adder of process run times to a clock. Use the value of the clock to determine if new processes need to be added to your queue.

Some students have tried to write a program that increments the clock one tick at a time. This is the difficult way to do it and is also incorrect.

The context switch cost is negligible and is not figured into this assignment.

Output:

With this process list, the output of your program should look like this:

# ./assn3 First Come, First Served Avg. Resp.:276.40, Avg. T.A.:448.90, Avg. Wait:276.40 Shortest Job First Avg. Resp.:202.90, Avg. T.A.:375.40, Avg. Wait:202.90 Shortest Remaining Time First Avg. Resp.:148.30, Avg. T.A.:353.30, Avg. Wait:180.80 Round Robin with Time Quantum of 100 Avg. Resp.:133.90, Avg. T.A.:555.90, Avg. Wait:383.40

Please note that each average displayed shows a result up to two decimal places.

THE DATA TO BE READ IN.....

For example in this data, 5 is the start time and 100 is the duration!

5 100

11 20

238 80

254 20

330 140

637 220

1042 360

1163 120

1364 170

1404 170

1737 180

1885 40

2149 190

2230 330

2273 360

2327 200

2441 190

2498 110

2875 250

2954 200