CSC2044 Assignment 1 — Bank Account Transaction System

Four Java programs that simulate how a bank account is accessed by multiple concurrent users, built to demonstrate concurrency, synchronisation, and race condition behaviour.

Overview

This project contains four programs that isolate key concurrent programming concepts:

Program	Task	Purpose
BankTransaction_Task2.java	Task 2	Sequential transaction processing
BankTransaction_Task3.java	Task 3	Concurrent transaction processing
BankRaceCondition.java	Task 5	Race condition demonstration (unsafe)
BankSynchronize.java	Task 6	Synchronisation solution (corrected)

Concepts Demonstrated

• Multithreading — four concurrent transaction workers (deposit, withdrawal, balance check, service charge) operating on a shared BankAccount object
• Sequential vs. concurrent execution — start()/join() patterns that control whether threads run one-at-a-time or simultaneously
• Race conditions — unsynchronised read-modify-write operations on a shared heap field producing non-deterministic, incorrect balances
• Synchronisation — synchronized(lock) blocks that enforce mutual exclusion over the critical section, guaranteeing correctness across all runs
• Heap vs. stack memory — shared mutable state (balance, lock) on the heap versus thread-private local variables (amount, txNum) on each thread's stack

Getting Started

Prerequisites

• Java JDK 11 or higher
• Any IDE (Integrated Development Environment)

Steps to Download Program

1. Clone the repository:

git clone https://github.com/Justin-yww/CSC2044-Concurrent-Programming-Assingment1.git
cd CSC2044-Concurrent-Programming-Assingment1

2. Verify the files are present:

ls *.java

Compilation

javac BankTransaction_Task2.java
javac BankTransaction_Task3.java
javac BankRaceCondition.java
javac BankSynchronize.java

Running

java BankTransaction_Task2    # Sequential
java BankTransaction_Task3    # Concurrent
java BankRaceCondition        # Race condition (unsafe)
java BankSynchronized         # Synchronised (corrected)

Group Members

Name	Student ID
Lau Ching Hau	21057799
Lee Chia Khang	21060389
Lee Seng Wai	23102627
Justin Yong Wenn Weii	18119677