kxo: A Tic-Tac-Toe Game Engine implemented as Linux kernel module

Introduction

kxo is a Linux kernel module that implements the tic-tac-toe game (aka XO Game) as kernel threads. This educational module demonstrates several essential Linux kernel programming concepts:

• Circular buffer implementation
• Mutex lock synchronization
• IRQ handling
• SoftIRQ processing
• Tasklet scheduling
• Workqueue management
• Kernel thread creation and execution

The module supports multiple AI algorithms for game strategy, allowing kernel threads to compete against each other in tic-tac-toe matches. kxo implements two advanced algorithms for tic-tac-toe gameplay:

• Monte Carlo Tree Search (MCTS): A probabilistic algorithm that uses random sampling to evaluate moves and determine optimal game strategies
• Negamax Algorithm: A depth-first minimax variant that efficiently evaluates game positions by alternating between maximizing and minimizing players

Build and Run

After the source code is downloaded, go into the directory and do as the following

$ make

Make sure the kernel object file (kxo.ko) is built correctly, then you can insert the kernel module

$ sudo insmod kxo.ko

kxo provides an interface for userspace interaction through the companion tool kxo-user. This utility offers the following functionality:

• Display the current status of the kxo module (loaded/unloaded)
• Real-time visualization of the tic-tac-toe game board
• Control commands:
  • Ctrl + P: Toggle pause/resume of the game board display
  • Ctrl + Q: Terminate all tic-tac-toe games running in kernel space

Simply run the command below after the kernel module is loaded:

$ sudo ./kxo-user

License

kxo is released under the MIT license. Use of this source code is governed by a MIT-style license that can be found in the LICENSE file.