C++ System Programming Cookbook: Practical recipes for Linux system-level programming using the latest C++ features

C++ System Programming Cookbook

Practical recipes for Linux system-level programming using the latest C++ features

Onorato Vaticone

BIRMINGHAM - MUMBAI

C++ System Programming Cookbook

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First published: February 2020

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Contributors

About the author

Onorato Vaticone is a software engineer with over 18 years of experience. A C++ expert, he has deep, system-level programming experience. An Agile coach and XP advocate, TDD and Simple Design are his everyday tools. He has worked on real-time systems (defense and energy transmission) with C++. During this time, he learned to write multiplatform code. Early in his career, he realized that a form of agility was needed. He holds an MSc in cloud computing and a BSc in computer engineering and software. He finds learning how things work under the hood to be fascinating!

About the reviewers

Scott Hutchinson leads a team of C++ and F# developers in Oxnard, California. After a few years as a VB/VBA developer, he started developing with .NET Framework immediately after its launch in 2002. Since 2016, he has done most of his development in C++. He is a mentor for the F# track on Exercism, and teaches functional programming in F# to his team at work. His main professional interests are functional programming and machine learning. When he's not learning some new software development skill, he's usually hiking in the mountains of Southern California.

Daniel Durante is an author and technical editor for Packt Publishing, a consultant and strategist for multiple Fortune 100 companies, and has been a full-stack developer since the age of 12. His code exists in infrastructures such as Hubcash, Stripe, and Walmart.

He has worked on text-based browser games that have reached over 1,000,000 active players, created bin-packing software for CNC machines, embedded programming with Cortex-M and PIC circuits, built high-frequency trading applications, and helped contribute to and maintain one of the oldest ORMs of Node.js (SequelizeJS). He has worked on various books such as Rust Standard Library Cookbook, PostgreSQL Developer's Guide, and Rust Programming By Example, among many others.

I would like to thank my parents, my brother, my mentors, and friends who have all put up with my insanity sitting in front of a computer day in and day out. I would not be here today if it wasn't for their patience, guidance, and love.

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Table of Contents

Title Page

Copyright and Credits

C++ System Programming Cookbook

About Packt

Why subscribe?

Contributors

About the author

About the reviewers

Packt is searching for authors like you

Preface

Who this book is for

What this book covers

To get the most out of this book

Download the example code files

Download the color images

Code in Action

Conventions used

Sections

Getting ready

How to do it…

How it works…

There's more…

See also

Get in touch

Reviews

Getting Started with System Programming

Technical requirements

Learning the Linux fundamentals - architecture

How to do it...

How it works...

Learning the Linux fundamentals - shell

How to do it...

How it works...

There's more...

See also

Learning the Linux fundamentals - users

How to do it...

How it works...

There's more...

See also

Using a makefile to compile and link a program

How to do it...

How it works...

There's more...

Using GDB to debug a program

How to do it...

How it works...

There's more...

Learning the Linux fundamentals - processes and threads

How to do it...

How it works...

There's more...

Handling a Linux bash error

How to do it...

How it works...

There's more...

Handling Linux code error

How to do it...

How it works...

There's more...

Revisiting C++

Technical requirements

Understanding C++ primitive types

How to do it...

How it works...

There's more...

See also

Lambda expressions

How to do it...

How it works...

There's more...

See also

Automatic type deduction and decltype

How to do it...

How it works...

There's more...

See also

Learning how atomic works

How to do it...

How it works...

There's more...

See also

Learning how nullptr works

How to do it...

How it works...

There's more...

See also

Smart pointers – unique_ptr and shared_ptr

How to do it...

How it works...

There's more...

See also

Learning how move semantics works

How to do it...

How it works...

There's more...

See also

Understanding concurrency

How to do it...

How it works...

There's more...

See also

Understanding the filesystem

How to do it...

How it works...

There's more...

See also

The C++ Core Guidelines

Getting ready

How to do it...

How it works...

There's more...

See also

Adding GSL in your makefile

Getting ready

How to do it...

How it works...

There's more...

See also

Understanding concepts

How to do it...

How it works...

There's more...

See also

Using span

How to do it...

How it works...

There's more...

See also

Learning how Ranges work

How to do it...

How it works...

There's more...

See also

Learning how modules work

How to do it...

How it works...

There's more...

See also

Dealing with Processes and Threads

Technical requirements

Starting a new process

How to do it...

How it works...

There's more...

See also

Killing a process

Getting ready

How to do it...

How it works...

There's more...

Creating a new thread

How to do it...

How it works...

There's more...

See also

Creating a daemon process

How to do it...

How it works...

There's more...

See also

Deep Dive into Memory Management

Technical requirements

Learning automatic versus dynamic memory

How to do it...

How it works...

There's more...

See also

Learning when to use unique_ptr, and the implications for size

How to do it...

How it works...

There's more...

See also

Learning when to use shared_ptr, and the implications for size

How to do it...

How it works...

There's more...

See also

Allocating aligned memory

How to do it...

How it works...

There's more...

See also

Checking whether the memory allocated is aligned

How to do it...

How it works...

There's more...

See also

Dealing with memory-mapped I/O

How to do it...

How it works...

There's more...

See also

Dealing with allocators hands-on

How to do it...

How it works...

There's more...

See also

Using Mutexes, Semaphores, and Condition Variables

Technical requirements

Using POSIX mutexes

How to do it...

How it works...

There's more...

See also

Using POSIX semaphores

How to do it...

How it works...

There's more...

See also

POSIX semaphores advanced usage

How to do it...

How it works...

There's more...

See also

Synchronization building blocks

How to do it...

How it works...

There's more...

See also

Learning inter-thread communication with simple events

How to do it...

How it works...

There's more...

See also

Learning inter-thread communication with condition variables

How to do it...

How it works...

There's more...

See also

Pipes, First-In First-Out (FIFO), Message Queues, and Shared Memory

Technical requirements

Learning the different types of IPC

How to do it...

How it works...

There's more...

See also

Learning how to use the oldest form of IPC – pipes

How to do it...

How it works...

There's more...

See also

Learning how to use FIFO

How to do it...

How it works...

There's more...

See also

Learning how to use message queues

How to do it...

How it works...

There's more...

See also

Learning how to use shared memory

How to do it...

How it works...

There's more...

See also

Network Programming

Technical requirements

Learning the basics of connection-oriented communication

How to do it...

How it works...

There's more...

See also

Learning the basics of connectionless-oriented communication

How to do it...

How it works...

There's more...

See also

Learning what a communication endpoint is 

How to do it...

How it works...

There's more...

See also

Learning to use TCP/IP to communicate with processes on another machine

How to do it...

How it works...

There's more...

See also

Learning to use UDP/IP to communicate with processes on another machine

How to do it...

How it works...

There's more...

See also

Dealing with endianness

How to do it...

How it works...

There's more...

See also

Dealing with Console I/O and Files

Technical requirements

Implementing I/O to and from the console

How to do it...

How it works...

There's more...

See also

Learning how to manipulate I/O strings

How to do it...

How it works...

There's more...

See also

Working with files

How to do it...

How it works...

There's more...

See also

Dealing with Time Interfaces

Technical requirements

Learning about the C++ time interface

How to do it...

How it works...

There's more...

See also

Using the C++20 calendar and time zone

How to do it...

How it works...

There's more...

See also

Learning the Linux timing

How to do it...

How it works...

There's more...

See also

Dealing with time sleep and overruns

How to do it...

How it works...

There's more...

See also

Managing Signals

Technical requirements

Learning all of the signals and their default actions

How to do it...

How it works...

There's more...

See also

Learning how to ignore a signal

How to do it...

How it works...

There's more...

See also

Learning how to trap a signal

How to do it...

How it works...

There's more...

See also

Learning how to send a signal to another process

How to do it...

How it works...

There's more...

See also

Scheduling

Technical requirements

Learning to set and get a scheduler policy

How to do it...

How it works...

There's more...

See also

Learning to get the timeslice value

How to do it...

How it works...

There's more...

See also

Learning how to set a nice value

How to do it...

How it works...

There's more...

See also

Learning how to yield the processor

How to do it...

How it works...

There's more...

See also

Learning about processor affinity

How to do it...

How it works...

There's more...

See also

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Preface

This book aims to provide ready-to-use solutions (to developers) for the essential aspects of system programming, using the latest C++ standards wherever possible. System programming deals with structuring computer programs that closely interact with the operating system and allow computer hardware to interface with the programmer and the user. Due to its efficient features, namely, low-level computation, data abstraction, and object-oriented features, C++ is the preferred language for system programming. You will learn how to create robust and concurrent systems, and you will also understand the inter-process communication mechanism with shared memory and pipe. Moving forward, you will deep dive into the C++ built-in libraries and frameworks in order to design robust systems as per your requirements.

Who this book is for

This book is for C++ developers who want to gain practical knowledge of systems programming. Though no experience of Linux system programming is assumed, intermediate knowledge of C++ is necessary.

What this book covers

Chapter 1, Getting Started with System Programming, introduces you to the fundamentals such as learning about the shell, users and groups, process IDs, and thread IDs to be able to use a Linux system proficiently and so on that you must know for the rest of the book. For example you will learn how Linux is designed, the shell, users and groups, process ID and thread IDs. Furthermore, you will learn how to develop a simple Hello World program, write its makefile, execute it, and debug it. This knowledge, although basic, is fundamental for the more advanced topics that will appear in later chapters.

Chapter 2, Revisiting C++, refreshes your understanding of C++17, which will be used throughout the entire book. It'll show why C++ represents a great opportunity for writing good quality code that is concise and more portable than ever. This chapter contains all the new features introduced by C++11/17/20 that you will find useful in this book.

Chapter 3, Dealing with Processes and Threads, introduces you to processes and threads that are the foundation of any elaboration. A program is rarely ever made of just one process. This chapter reveals the techniques for dealing with threads and processes in C++. The chapter will demonstrate how easy and convenient it is to deal with threads (and tasks) compared to POSIX. Although C++ does not have a formal way of creating a process, there are rare cases in which a thread cannot do the job.

Chapter 4, Deep Dive into Memory Management, introduces you to memory, which is one of the core concepts of dealing with system development. Allocating, freeing, and learning how memory is managed and what C++ can offer to simplify and manage memory is crucial. Furthermore, this chapter presents recipes on how to check and allocate aligned memory and how to deal with memory-mapped I/O. 

Chapter 5, Using Mutexes, Semaphores, and Condition Variables, shows us the POSIX mechanism solutions and the ones offered by C++ to synchronize threads and processes.

Chapter 6, Pipes, First-In First-Out (FIFO), Message Queues, and Shared Memory, focuses on making the processes communicate with each other. There are different solutions available – pipes, FIFO, message queues, and shared memory. For each inter-process communication mechanism, a recipe is provided.

Chapter 7, Network Programming, demonstrates how communication takes place from the connection to the end. Communication between processes on different machines is the foundation of the internet today, and TCP/IP is the standard de facto. Both TCP (short for Transmission Control Protocol) and UDP (short for User Datagram Protocol) will be described in detail, as the first represents connection-oriented and the latter represents connectionless-oriented. This is quite important these days, especially with the video streaming services that are available online.

Chapter 8, Dealing with Console I/O and Files, presents you with useful recipes for dealing with files, I/O to and from the console, and streams of strings.

Chapter 9, Dealing with Time Interfaces, provides you with a deep understanding of how to deal with and measure time with the features that are provided by both C++ and POSIX. The chapter will offer ready-to-use recipes for each method.

Chapter 10, Managing Signals, introduces us to signals that are software interrupts. They provide a way of managing asynchronous events. For example, a user typing the interrupt key from the terminal, or another process sending a signal that must be managed. Every signal has a name starting with SIG (for example, SIGABRT). This chapter will show the reader how to write code to properly manage software interrupts, what the default actions defined by Linux for each signal are, and how to override them.

Chapter 11, Scheduling, shows you how to use POSIX (the C++ standard does not provide this) to set scheduler parameters, the scheduler policy, and the scheduler priorities. System programming is about interacting with the underlying OS as seen so far. The scheduler is one of the main components of every OS and impacts the way processes are allocated on CPUs. There are cases where the developer needs control over this or, at least, tries to influence the scheduler.

To get the most out of this book

Here is a list of requirements for this book:

Intermediate knowledge of C++.

Any additional requirements are mentioned in the Technical requirements section of each chapter.

Disclaimer: The C++20 standard has been approved (that is, technically finalized) by WG21 in a meeting in Prague at the end of February. This means that the GCC compiler version that this book uses, 8.3.0, does not include (or has very, very limited support for) the new and cool C++20 features. For this reason, the Docker image does not include the C++20 recipe code.

GCC keeps the development of the newest features in branches (you have to use appropriate flags for that, for example, -std=c++2a); therefore, you are encouraged to experiment with them by yourself. So, clone and explore the GCC contracts and module branches and have fun.

Some recipes (especially in Chapter 11, Scheduling) require the Docker image running with admin privileges to execute properly. Depending