SkyWatch – Operating System Simulation

1. Project Overview

SkyWatch simulates a realistic Operating System (OS) for air traffic control, demonstrating process management, scheduling, and inter-process communication. It’s perfect for learning advanced OS concepts, process scheduling algorithms, and IPC mechanisms.

• Multi-Level Feedback Queue (MLFQ) scheduling
• Forked Process Management – Jet generation and lifecycle
• Inter-Process Communication – POSIX FIFOs for updates
• Signal Handling – Graceful termination and cleanup
• Real-time Monitoring – Queue and runway display
• Dynamic Jet Lifecycle – Fuel tracking, emergencies, runway allocation
• Logging – Event tracking for debugging and analysis

2. Tech Stack

• Language: C++17 or later
• Platform: Linux / WSL (POSIX-compliant)
• Compiler: g++ 7+
• Concurrency & IPC: fork(), select(), FIFOs, threads, mutex
• Storage: Local runtime logging
• Visualization: Terminal-based queue and radar display

3. Project Structure

SkyWatch_System_With_Threads_&_Pipes/
├── include/
│   └── skywatch.h
├── src/
│   ├── main.cpp
│   ├── scheduler.cpp
│   ├── jet.cpp
│   ├── display.cpp
│   └── atc.cpp
├── build.sh
├── .gitignore
├── LICENSE
└── README.md

4. Setup & Usage

chmod +x build.sh
./build.sh

or

./skywatch

5. Major Components

5.1 Jet Generator

• Forks jet child processes dynamically
• Creates FIFO for each jet
• Sends metadata to ATC
• Simulates random arrivals

5.2 ATC (Air Traffic Control)

• Event-driven controller using select()
• Manages scheduling queues
• Reads jet updates via FIFOs
• Allocates runways
• Handles user input commands

5.3 Scheduler (MLFQ)

• Three Priority Queues:

  • Q0 – Emergency Jets (Shortest Remaining Time First)
  • Q1 – Standard Jets (Round Robin)
  • Q2 – Batch Jets (FCFS)

• Dynamic promotion/demotion

• Aging to prevent starvation

• Selects next jet for runway

5.4 Display Module

• Real-time queue visualization
• Radar-style overview
• Jet status updates
• Runway occupancy display

5.5 Jet Process

• Individual jet simulation
• Fuel consumption tracking
• Queue traversal and emergency handling

6. Scheduling Workflow

1. Jet Created – Generator forks jet, FIFO created
2. ATC Receives Jet – JetInfo struct, assigned to queue
3. Scheduler Chooses Jet – Based on priority, fuel, time quantum
4. Running Jet – Communicates with ATC via FIFO
5. Jet Terminates – Signals ATC, FIFO removed, memory cleaned

7. Function Explanation

main.cpp

• Global state setup
• FIFO creation
• Signal handlers (SIGINT)
• Starts ATC loop

jet.cpp

• Jet lifecycle, fuel tracking, FIFO messaging

scheduler.cpp

• Queue management
• MLFQ scheduling, promotion/demotion
• Jet selection

display.cpp

• Terminal-based queue visualization

atc.cpp

• Main event loop
• Reads FIFO messages
• Processes user commands

8. Future Improvements

• Add GUI visualization
• Switch FIFOs to Unix domain sockets
• Thread-based jet simulation for Windows
• Configurable runtime parameters
• Export logs to JSON/CSV

9. Ethical & Legal Notice

• For educational and experimental purposes only
• Controlled environment testing
• Misuse for unauthorized access is prohibited

10. Author & Contact

Name: Mohid Umer
Email: mohidumer112@gmail.com

SkyWatch demonstrates OS scheduling, IPC, and process management through a technically rigorous, real-time simulation.