Book Image

Hands-On Design Patterns with Delphi

By : Primož Gabrijelčič
Book Image

Hands-On Design Patterns with Delphi

By: Primož Gabrijelčič

Overview of this book

Design patterns have proven to be the go-to solution for many common programming scenarios. This book focuses on design patterns applied to the Delphi language. The book will provide you with insights into the language and its capabilities of a runtime library. You'll start by exploring a variety of design patterns and understanding them through real-world examples. This will entail a short explanation of the concept of design patterns and the original set of the 'Gang of Four' patterns, which will help you in structuring your designs efficiently. Next, you'll cover the most important 'anti-patterns' (essentially bad software development practices) to aid you in steering clear of problems during programming. You'll then learn about the eight most important patterns for each creational, structural, and behavioral type. After this, you'll be introduced to the concept of 'concurrency' patterns, which are design patterns specifically related to multithreading and parallel computation. These will enable you to develop and improve an interface between items and harmonize shared memories within threads. Toward the concluding chapters, you'll explore design patterns specific to program design and other categories of patterns that do not fall under the 'design' umbrella. By the end of this book, you'll be able to address common design problems encountered while developing applications and feel confident while building scalable projects.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
About Packt


As we saw in the previous chapter, processing shared data from multiple threads introduces all sorts of problems that cannot be easily fixed especially if we want the program to executed faster than in a single—threaded version.

A common solution for this problem is to redesign the program. Instead of using the shared data access and locking pattern, we replace the shared data with multiple copies of the same and synchronize (lock) with the message pattern.


If you play chess on the internet, you are not sharing a chessboard with your partner. Instead, each of you have your own copy of the chessboard and figures, and you synchronize the state between the two copies by sending messages (representing the piece moves) to each other.

Messaging is not a design but an architectural pattern. The implementation of messaging is, however, usually specific to a platform or a language and can be considered almost an idiom. As the messaging pattern is extremely important if you want to write...