OS-CPU Scheduling Simulator

A modular C++ simulator for evaluating classic CPU scheduling policies on synthetic workloads. It implements:

• FCFS (First-Come, First-Serve)
• SRTF (Shortest Remaining Time First)
• MLFQ (Multi-Level Feedback Queue) with aging and global boosts

Workloads are defined in CSV, and the simulator produces both summary and per-job CSV outputs. A companion Python script generates visualizations (histogram, scatter plot, bar chart) to compare algorithm trade-offs.

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Features

• Clean Scheduler interface supporting preemptive and non-preemptive policies
• Three scheduling strategies with customizable parameters
• CSV-based I/O for easy integration with other tools
• Automatic metric computation:
  • Average waiting time
  • Average turnaround time
  • Average response time
  • CPU utilization
  • Throughput
• Python/Plotly visualization script for quick graphical analysis

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Requirements

• C++17 compiler (e.g. g++)
• Make (for the provided Makefile)
• Python 3 with the following packages:

  pip install pandas plotly

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Repository Layout

.
├── include/            # Header files (PCB, Scheduler interface, workload, simulator, metrics)
├── src/                # C++ implementations and main program
├── analyze/            # Python visualization (analyze.py) and run script
├── workloads/          # Example CSV workload traces
├── results/            # Generated output CSVs
├── Makefile            # Build instructions
├── runvis.sh           # Helper script for full run + visualization
└── README.md           # This file

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Building

make

Produces the cpu_sim executable.

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Running Simulations

./cpu_sim workloads/<your_workload.csv>

• Input: id, arrival, burst[, priority]
• Outputs:
  • results/results.csv – aggregated metrics per scheduler
  • results/results_detailed.csv – per-job timing details

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Visualization

cd analyze
python analyze.py ../results/results_detailed.csv

Opens plots in individual browser tabs.

Alternatively:

./runvis.sh workloads/<your_workload.csv>

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References

• GeeksforGeeks: MLFQ Scheduling
• Mistry, A.: Multi-Level Feedback Queue Scheduling
• Arpaci-Dusseau, R. H. & Arpaci-Dusseau, A. C.: CPU Scheduling (OSTEP)