Project 1 - CPU Scheduling Simulator

Overview

Maven-based Java project simulating CPU scheduling algorithms with a simple CLI. It loads processes from src/main/resources/processes.txt, executes a selected algorithm, and prints a Gantt chart and basic metrics.

Currently implemented:

• FCFS (First-Come, First-Served)
• RR (Round Robin, user-provided time quantum)

Implemented Functionality

• Process ingestion via ProcessUtils.ReadProcessInfo (classpath resource → ProcessObj list).
• ProcessObj model with PID, arrival, burst, priority, plus computed metrics.
• Sorting helper ProcessSort.byArrivalTime.
• FCFS in FCFSScheduler.schedule (non-preemptive).
• Round Robin in RRScheduler.schedule (preemptive with quantum, handles idle gaps).
• Text-mode Gantt chart via GanttChart.print (inserts IDLE when appropriate).
• Metrics via Metrics.print (per-process WT/TAT and averages).
• Main CLI to select the algorithm and (for RR) prompt for quantum.

Input Data

The simulator expects a whitespace-delimited file with four columns: PID ARRIVAL BURST PRIORITY. The included sample is at src/main/resources/processes.txt. The first line is treated as a header; subsequent lines should contain integers.

Building and Running

1. Compile the project:
   • mvn clean compile
   • or javac -d target/classes src/main/java/edu/osproject25/*.java
2. Run the CLI (after compiling):
   • java -cp target/classes edu.osproject25.Main

You will be prompted to choose an algorithm:

• Enter 1 for FCFS
• Enter 2 for Round Robin (you can then provide a positive integer quantum)

Example output shape:

========== CPU Scheduling Simulator ==========
Loaded N processes from processes.txt

| P1 | P2 | IDLE| P3 |
0    5     9    10   14

Process P1: WT = 0, TAT = 5
Process P2: WT = 2, TAT = 7
...
Average Waiting Time: 3.25
Average Turnaround Time: 8.50

Notes

• All times share the same unit (e.g., milliseconds, ticks). Choose any consistent unit for input.
• For RR, the quantum must be a positive integer.