Assignment 4: CPU Scheduling Simulation

Overview

This C program simulates three classic CPU scheduling algorithms:

• First-Come, First-Served (FCFS)
• Shortest Job First (SJF)
• Round Robin (RR)

It reads process data from an input file and calculates waiting time and turnaround time for each process according to the selected scheduling algorithm.

Functionality

• Accepts a CSV input file where each line represents a process:

  P0,3
  P1,5
  ...
  

  Each line contains the process ID and its burst time.

• Simulates the following algorithms:

  • -f for FCFS
  • -s for SJF
  • -r quantum for Round Robin with a user-specified time quantum

• Outputs per-time-unit execution along with each process’s burst left, wait time, and turnaround time.

• Displays final statistics:

  • Per-process wait and turnaround times
  • Total average wait and turnaround times

Compilation

gcc assignment-4.c -o assignment4

Usage

./assignment4 -f infile.csv       # First-Come, First-Served
./assignment4 -s infile.csv       # Shortest Job First
./assignment4 -r 2 infile.csv     # Round Robin with quantum 2

Sample Output

T0: P0 - Burst left 3, Wait time 0, Turnaround time 0
T1: P0 - Burst left 2, Wait time 0, Turnaround time 1
...
P0
Waiting time:     0
Turnaround time:  3

Total average waiting time:     2.5
Total average turnaround time:  4.0

Notes

• Processes are assumed to arrive at time proportional to their process number (e.g., P0 at T0, P1 at T1).
• Time quantum for RR must be a positive integer.
• Output is printed to standard output.

License

This project is part of CS 3305A - Operating Systems at Western University. For academic use only.