Book Image

Hands-On System Programming with C++

By : Dr. Rian Quinn
Book Image

Hands-On System Programming with C++

By: Dr. Rian Quinn

Overview of this book

C++ is a general-purpose programming language with a bias toward system programming as it provides ready access to hardware-level resources, efficient compilation, and a versatile approach to higher-level abstractions. This book will help you understand the benefits of system programming with C++17. You will gain a firm understanding of various C, C++, and POSIX standards, as well as their respective system types for both C++ and POSIX. After a brief refresher on C++, Resource Acquisition Is Initialization (RAII), and the new C++ Guideline Support Library (GSL), you will learn to program Linux and Unix systems along with process management. As you progress through the chapters, you will become acquainted with C++'s support for IO. You will then study various memory management methods, including a chapter on allocators and how they benefit system programming. You will also explore how to program file input and output and learn about POSIX sockets. This book will help you get to grips with safely setting up a UDP and TCP server/client. Finally, you will be guided through Unix time interfaces, multithreading, and error handling with C++ exceptions. By the end of this book, you will be comfortable with using C++ to program high-quality systems.
Table of Contents (16 chapters)

Introducing the C++ allocators

C++ allocators define a template class that allocates memory for a specific type T and are defined by the allocator concept definition. There are two different types of allocators:

  • Allocators that are equal
  • Allocators that are unequal

An allocator that is equal is an allocator that can allocate memory from one allocator and deallocate memory from another, for example:

myallocator<myclass> myalloc1;
myallocator<myclass> myalloc2;

auto ptr = myalloc1.allocate(1);
myalloc2.deallocate(ptr, 1);

As shown in the preceding example, we create two instances of myallocator{}. We allocate memory from one of the allocators and then deallocate memory from the other allocator. For this to be valid, the allocators must be equal:

myalloc1 == myalloc2; // true

If this does not hold true, the allocators are considered unequal, which greatly complicates how...