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)

Memory management functions

Besides the various internal functions that the Delphi RunTime Library (RTL) uses to manage strings, arrays, and other built-in data types, RTL also implements various functions that you can use in your program to allocate and release memory blocks. In the next few paragraphs, I’ll tell you a little bit about them.

Memory management functions can be best described if we split them into a few groups, each including functions that were designed to work together. Let’s take a closer look at these groups:

  • The first group includes GetMem, AllocMem, ReallocMem, and FreeMem.

The GetMem(var P: Pointer; Size: Integer) procedure allocates a memory block of size Size and stores an address of this block in a pointer variable, P. This pointer variable is not limited to the pointer type but can be of any pointer type (for example, PByte).

The new memory block is not initialized and will contain whatever is stored in the memory at that...