Book Image

Delphi High Performance - Second Edition

By : Primož Gabrijelčič
5 (1)
Book Image

Delphi High Performance - Second Edition

5 (1)
By: Primož Gabrijelčič

Overview of this book

Performance matters! Users hate to use programs that are not responsive to interactions or run too slow to be useful. While becoming a programmer is simple enough, you require dedication and hard work to achieve an advanced level of programming proficiency where you know how to write fast code. This book begins by helping you explore algorithms and algorithmic complexity and continues by describing tools that can help you find slow parts of your code. Subsequent chapters will provide you with practical ideas about optimizing code by doing less work or doing it in a smarter way. The book also teaches you how to use optimized data structures from the Spring4D library, along with exploring data structures that are not part of the standard Delphi runtime library. The second part of the book talks about parallel programming. You’ll learn about the problems that only occur in multithreaded code and explore various approaches to fixing them effectively. The concluding chapters provide instructions on writing parallel code in different ways – by using basic threading support or focusing on advanced concepts such as tasks and parallel patterns. By the end of this book, you’ll have learned to look at your programs from a totally different perspective and will be equipped to effortlessly make your code faster than it is now.
Table of Contents (15 chapters)

Background Worker

It is now time to introduce the first complex pattern in this chapter – Background Worker. It establishes a background server module running on multiple threads, to which we can queue data packets for processing. This module has its own input queue (a blocking collection, of course!) that holds unprocessed data, and an output queue that holds the results of processing until they are returned to the main thread.

Later in this chapter, you’ll see that a background worker looks very similar to a single stage of a pipeline. This is true – in fact, a background worker is implemented as a wrapper around the pipeline pattern! It does, however, implement important functionality that is not part of the pipeline pattern – namely, it can cancel work requests while they wait to be processed. We will see in the example how that can be of use.

Another nice feature of the background worker is that it provides a clean way to set up and tear down...