🧵 Reader-Writer Synchronization (C++ pthreads)

A multithreaded C++ console application that simulates the classic Reader-Writer Problem using POSIX threads, mutexes, and semaphores. This project was built on Ubuntu 24.04 to explore thread synchronization techniques in a multi-threaded system.

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💡 Project Overview

This simulation was originally developed as part of an academic group project for the Operating System Lab (KT24403) course at Universiti Malaysia Sabah (UMS). It demonstrates synchronization control where multiple reader and writer threads access a shared file concurrently.

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🚀 Features

• 📖 Multiple reader threads can read simultaneously
• ✍️ Writers gain exclusive access to write
• 🔒 Synchronization using pthread_mutex_t and sem_t
• 🧮 Custom input: number of readers/writers and cycles
• 📂 Uses actual file I/O with io_shared_file.txt
• 🧾 Console log output for each thread’s activity

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🛠️ Built With

• C++ (G++ Compiler)
• POSIX Threads (pthreads)
• Ubuntu 24.04
• Terminal-based interaction and file I/O

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📁 Project Structure

ReaderWriterSync/
├── main.cpp # Full thread and logic implementation
├── io_shared_file.txt # Shared file for read/write operations
├── README.md # This file
└── LICENSE # MIT License

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▶️ How to Run (Ubuntu)

1. Clone this repository:

   bash
   git clone https://github.com/anake-an/ReaderWriterSync.git
   cd ReaderWriterSync
   

2. Compile using g++:

   g++ -o sync main.cpp -l pthread
   

3. Run the program:

   ./sync
   

4. Provide required input (number of threads and cycles) when prompted.

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📊 Example Test Scenarios

These test cases were executed on Ubuntu 24.04 to validate synchronization correctness.

Test Case	Action	Expected Result	Outcome
TC1	2 readers start together	Both readers can read the file simultaneously	✅ PASS
TC2	1 writer starts while readers active	Writer waits until all readers finish before writing	✅ PASS
TC3	1 reader starts during writer	Reader waits until writer finishes	✅ PASS
TC4	2 writers active	Only one writer writes at a time, the other waits	✅ PASS
TC5	Full simulation with many threads	No deadlocks, race conditions, or crashes	✅ PASS
TC6	Writer writes → reader reads	Reader can read new content written by writer	✅ PASS

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👥 Contributors

This project was originally developed as a group assignment for the KT24403 Operating System Lab course.

Name	Profile Link
Aniq Najmuddin Bin Sharifuddin	Linkedin
Muhammad Faris Bin Huzaimi	LinkedIn
Muhammad Isyraf Ahnaf Bin M. Zamri	LinkedIn
Muhammad Saifullah Bin Rosman	LinkedIn