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)

Optimizing method calls

I know you are eagerly waiting to optimize some real code, but be patient as we discuss a little bit more about the theoretical side of the process. I spent a lot of time talking about the behavior of built-in data types, but I didn’t say anything about how data is passed to methods. This much shorter and more surprising section (you’ll see!) will remedy this. As I’ll be talking about speeding up method calls, I’ll also throw in a short discussion about method inlining, just for good measure. But first, parameters!

Parameter passing

In essence, Delphi knows two ways of passing parameters to a method (or a procedure, function, or anonymous method – it’s all the same). Parameters can be passed by value or by reference.

The former makes a copy of the original value and passes that copy to a method. The code inside the method can then modify its copy however it wants, without changing the original value.

The...