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


This chapter opened with the topic of Concurrency patterns by exploring five different patterns related to managing access to shared data from multiple threads.

We learned that the lock pattern ensures that two threads are not trying to modify shared data or an object at the same time. It is also useful when one thread is reading from a shared object while another wants to modify it. We explored three different implementations of this pattern and compared their advantages and disadvantages.

We also learned that the lock pattern can be improved by introducing lock striping—a pattern that further fragments data inside one object and protects it with multiple locks instead of one. This approach is useful when we manipulate data in a list or array and don't add or remove existing elements. We explored two use possibilities, adding an array of locks or using one unused bit of existing data in combination with a custom locking solution.

After that, we spent some time exploring the lazy creation...