The Bridge Problem - Multithreading Visualization

Project README

Authors

• Marcin Bator
• Wiktor Mazur

University

Rzeszów University of Technology, 2023

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Table of Contents

1. Project Assumptions
2. Implementation Agenda
3. Technologies
   • 3.1 Front-end (Client Side)
   • 3.2 Back-end (Server Side)
4. Front-end Implementation Details
   • 4.1 Overview
   • 4.2 API Communication
5. Back-end Implementation Details
   • 5.1 Overview
   • 5.2 Endpoints (Web Layer)
   • 5.3 Service (Server Layer)
6. Summary
7. Running locally

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1. Project Assumptions

The project addresses a synchronization problem on a two-way road with a narrow bridge. The goal is to ensure collision-free passage for cars from both the south and north directions.

2. Implementation Agenda

The solution is a web application accessible through a browser. It utilizes server-side code with multithreading implemented on the back-end server. Users can spawn cars, set their direction, and customize crossing times. The application is fully dockerized for easy deployment.

3. Technologies

3.1 Front-end (Client Side)

• React 18
• Next.js 14.0.4
• TypeScript 5
• Tailwind CSS 3.3.0

3.2 Back-end (Server Side)

• Java 17.09
• Spring Boot 3.2
• Apache Maven

4. Front-end Implementation Details

4.1 Overview

The application features a user-friendly UI allowing car addition, directional selection, and control over passing cars. It includes a visualization of cars, red/green lights, and queue status. Car crossing times are randomly generated upon addition.

4.2 API Communication

Front-end communicates with the back-end API on port 8080, using standard JS fetch and await every 10 milliseconds to get car states.

5. Back-end Implementation Details

5.1 Overview

The back-end utilizes Spring Boot with 6 REST endpoints, handling car addition, retrieval, direction, passing limits, and scheduled removal of processed cars.

5.2 Endpoints (Web Layer)

• GET('/api/cars'): Returns the list of all cars.
• POST('/api/add-car'): Adds a new car to the program.
• GET('/api/direction'): Returns the current direction.
• GET('/api/max-cars'): Returns the current passing limit.
• POST('/api/max-cars'): Sets a new passing limit.
• SCHEDULED: Deletes cars passed the bridge for at least 5 seconds.

5.3 Service (Server Layer)

The core class, BridgeService, manages car queues and threading. It ensures synchronized single-car bridge crossing.

6. Summary

The multithreading solution in Java addresses the bridge problem. Using React and Spring Boot, the web application enhances understanding of multithreading concepts in a visual and interactive manner.

7. Running locally

Clone repository, then open in the terminal and launch docker-compose up.