Concurrent Transaction Processor

A concurrent banking system simulator written in modern C++17, designed to process financial transactions safely using multi-threading, mutex synchronization, and design patterns (Producer–Consumer + Observer).

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Overview

This project simulates a real-world banking transaction processor where multiple threads handle deposits, withdrawals, and rollbacks concurrently.
It demonstrates key system design principles like thread synchronization, event-driven updates, and rollback recovery — all using pure C++ standard libraries.

Core Highlights

• Multi-threaded transaction queue using the Producer–Consumer pattern
• Automatic rollback handling using the Observer pattern
• CSV-based persistence for transaction and account records
• Thread-safe balance updates with std::mutex
• Simulated concurrency delay and rollback synchronization
• Clean modular structure (Header + Source separation)

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Diagram

🧠 Design Patterns Used

1. Producer–Consumer Pattern

• The system uses a shared transaction queue.
• Producers read and push transaction data from CSV.
• Multiple consumer threads process transactions concurrently.

2. Observer Pattern

• A dedicated rollback thread observes processed transactions.
• On rollback-triggered events, it automatically adjusts account balances.

Usage

• Scalable And Maintainable code
• High performance systems
• Real-time transaction monitoring and rollback recovery

How to Run

• Your system must have C++ version >= 11 because of thread dependancy
• Clone the repo , cd Concurrent Transaction Proccesor
• run in windows powershell or equivalent terminal in linux or mac : g++ "src/Transaction.cpp" "src\Rollback.cpp" "src/main.cpp" -I "include" -o main
• run main.exe