Rainer Grimm - Concurrency with Modern C++

Bart Vandewoestyne

Senior Development Engineer Software at Esterline

Ian Reeve

Senior Storage Software Engineer for Dell Inc.

Robert Badea

Technical Team Leader

Concurrency with Modern C++ is a journey through present and upcoming concurrency features in C++.

• C++11 and C++14 have the basic building blocks for creating concurrent and parallel programs.
• With C++17 we have the parallel algorithms from the Standard Template Library (STL). That means that most STL based algorithms can be executed sequentially, parallel, or vectorised.
• The concurrency story in C++ goes on. With C++20/23 we can hope for extended futures, coroutines, transactions, and more.

This book explains the details of concurrency in modern C++ and gives you, also, many code examples. Therefore you can combine theory with practice to get the most out of it.

Because this book is about concurrency, I present many pitfalls and show you how to overcome them.

Only a few conventions.

Italic: I use Italic to emphasise an expression.

Bold: I use Bold to emphasise even more.

Monospace: I use Monospace for code, instructions, keywords, and names of types, variables, functions, and classes.

stands for a conclusion in the mathematical sense. For example, a b means if a then b.

Boxes contain special information, tips, and warnings.

Information text.

Tip description.

Warning description.

All source code examples are complete. That means, assuming you have a conforming compiler, you can compile and run them. The name of the source file is in the title of the listing.I use the using namespace std directive in the source files only if necessary.

Compiling and running the examples is quite easy for the C++11 and C++14 examples in this book. Every modern C++ compiler should support them. For both the GCC and the clang compiler, the C++ standard must be specified as well as the threading library to link against. For example the g++ compiler from GCC creates an executable program called thread with the following command-line: g++ -std=c++14 -pthread thread.cpp -o thread.

• -std=c++14: use the language standard C++14
• -pthread: add support for multithreading with the pthread library
• thread.cpp: source file
• -o thread: executable program

The same command-line works for the clang++ compiler. The Microsoft Visual Studio 17 C++ compiler supports C++14 as well.

If you have no modern C++ compiler at your disposal, there are a lot of online compilers available. Arne Mertz blog post C++ Online Compiler gives an excellent overview.

With C++17 and C++20/23, the story becomes quite complicated. I installed the and read how you can see the code examples in action.

If you are not very familiar with concurrency in C++, start at the very beginning with to get the big picture.

Once you get the big picture, you can proceed with the should help you apply the theory, something that is sometimes quite challenging as it requires a basic understanding of the memory model.

The chapter is optional. I am very curious about the future. I hope you are too!

The last part, provides you additional guidance towards a better understanding of my book and getting the most out of it.

To write this book in English, I started a request in my English blog: www.ModernesCpp.com and received a much higher response than I expected. About 50 people wanted to proofread my book. Special thanks to all of you, including my daughter Juliette, who improved my layout and my son Marius, who was the first proofreader.

Here are the names in alphabetic order: Nikos Athanasiou, Robert Badea, Joe Das, Jonas Devlieghere, Randy Hormann, Lasse Natvig, Erik Newton, Ian Reeve, Bart Vandewoestyne, Dafydd Walters, Andrzej Warzynski, and Enrico Zschemisch.

Ive worked as a software architect, team lead and instructor for about 20 years. In my spare time, I enjoy writing articles on topics such as C++, Python and Haskell, and also enjoy speaking at conferences. In 2016 I decided to work for myself. I organise and lead seminars about modern C++ and Python.

I began Concurrency With Modern C++ in Oberstdorf while getting a new hip joint. Formally, it was a total endoprosthesis of my left hip joint. I wrote the first half of this book during my stay in the clinic and the rehabilitation clinic. To be honest, writing a book helped me a lot during this challenging period.