Many-to-Many OS Thread Scheduler Simulator

Overview

This project is an interactive Many-to-Many (M:N) Thread Model Simulator built to demonstrate how modern operating systems efficiently manage concurrency. It provides a real-time visualization of thread scheduling, bridging the gap between user space, kernel space, and actual hardware execution.

It visualizes how:

• Multiple User Threads (M) are created and managed by a thread library.
• They are mapped to multiple Kernel Threads (N).
• Kernel threads are subsequently scheduled and executed on available CPU cores.

The simulator features a responsive UI and a robust frontend simulation engine, making it ideal for:

• 📚 Operating System learning
• 🎓 College projects & vivas
• 🧠 Understanding thread scheduling, context switching, and concurrency

Features

• Real-Time Visualization: Watch user threads transition between states (Ready, Running, Blocked, Completed) and get mapped to kernel threads and CPU cores.
• Dynamic Configuration:
  • Adjust the number of User Threads (M), Kernel Threads (N), and CPU Cores.
  • Adjust simulation speed on the fly.
• Scheduling Algorithms: Supports switching between:
  • Round Robin (RR)
  • First Come First Serve (FCFS)
• Interactive Scenarios:
  • Manually spawn new user threads during execution.
  • Trigger I/O blocks randomly to simulate real-world blocking operations.
• Live Metrics Dashboard: Tracks simulation time, CPU utilization, context switches, and throughput.

Core Concepts Demonstrated

• Many-to-Many Thread Model (M:N)
• User-Level Threads vs. Kernel-Level Threads
• CPU Scheduling Algorithms (RR, FCFS)
• Context Switching
• Thread Lifecycles (Ready, Running, Blocked, Completed)
• Concurrency & Parallelism
• I/O Blocking & Unblocking

Technologies Used

• HTML5: Semantic structure for the layout.
• CSS3: Advanced styling, flexbox/grid layouts, dynamic animations, and custom UI components.
• JavaScript (ES6 Modules):
  • simulator.js: Handles the core engine logic, thread lifecycles, state management, and scheduling algorithms.
  • ui.js: Manages DOM manipulation, event listeners, dynamic visualizations, and live metrics updates.

How to Run

Since this is a vanilla frontend project, no complex server setup is required.

1. Clone or download the repository.
2. Open index.html in any modern web browser (e.g., Chrome, Edge, Firefox, Safari).
3. Alternatively, you can use a local server like VS Code's "Live Server" extension for a better development experience.

Usage Guide

1. Configure Parameters: Use the sliders on the left panel to set the desired number of User Threads, Kernel Threads, and CPU Cores before starting.
2. Select Scheduling Algorithm: Choose either Round Robin (RR) or First Come First Serve (FCFS) for the kernel space scheduling.
3. Control Simulation: Use the Start, Pause, and Reset buttons to control the flow.
4. Interact: While the simulation is running, try spawning a new user thread or triggering an I/O block to observe how the scheduler dynamically reacts.
5. Observe Metrics: Keep an eye on the top metrics bar to see how different configurations and workloads affect CPU Utilization and Throughput.

License

This project is open-source and available for educational and personal use. Feel free to modify and adapt it for your own assignments or learning.