Book Image

Delphi High Performance

By : Primož Gabrijelčič
Book Image

Delphi High Performance

By: Primož Gabrijelčič

Overview of this book

Delphi is a cross-platform Integrated Development Environment (IDE) that supports rapid application development for Microsoft Windows, Apple Mac OS X, Google Android, iOS, and now Linux with RAD Studio 10.2. This book will be your guide to build efficient high performance applications with Delphi. The book begins by explaining how to find performance bottlenecks and apply the correct algorithm to fix them. It will teach you how to improve your algorithms before taking you through parallel programming. You’ll then explore various tools to build highly concurrent applications. After that, you’ll delve into improving the performance of your code and master cross-platform RTL improvements. Finally, we’ll go through memory management with Delphi and you’ll see how to leverage several external libraries to write better performing programs. By the end of the book, you’ll have the knowledge to create high performance applications with Delphi.
Table of Contents (16 chapters)
Title Page
Copyright and Credits
Packt Upsell


The next pattern I want to present is Join. This is a very simple pattern that starts multiple tasks in parallel. In the Parallel Programming Library, Join is implemented as a class method of the TParallel class. To execute three methods,  Task1, Task2, and Task3, in parallel, you simply call TParallel.Join with parameters collected in an array:

TParallel.Join([Task1, Task2, Task3]);

This is equivalent to the following implementation, which uses tasks:

  tasks: array [1..3] of ITask;

tasks[1] := TTask.Run(Task1);
tasks[2] := TTask.Run(Task2);
tasks[3] := TTask.Run(Task3);


Although the approaches work the same, that doesn't mean that Join is implemented in this way. Rather than that, it uses a pattern that I haven't yet covered, a parallel for to run tasks in parallel.

The Join starts tasks but doesn't wait for them to complete. It returns an ITask interface representing a new, composite task, which only exits when all of its subtasks finish execution. You can do with this task anything...