Book Image

Mastering C++ Multithreading

By : Maya Posch
Book Image

Mastering C++ Multithreading

By: Maya Posch

Overview of this book

Multithreaded applications execute multiple threads in a single processor environment, allowing developers achieve concurrency. This book will teach you the finer points of multithreading and concurrency concepts and how to apply them efficiently in C++. Divided into three modules, we start with a brief introduction to the fundamentals of multithreading and concurrency concepts. We then take an in-depth look at how these concepts work at the hardware-level as well as how both operating systems and frameworks use these low-level functions. In the next module, you will learn about the native multithreading and concurrency support available in C++ since the 2011 revision, synchronization and communication between threads, debugging concurrent C++ applications, and the best programming practices in C++. In the final module, you will learn about atomic operations before moving on to apply concurrency to distributed and GPGPU-based processing. The comprehensive coverage of essential multithreading concepts means you will be able to efficiently apply multithreading concepts while coding in C++.
Table of Contents (17 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
8
Atomic Operations - Working with the Hardware

Tracing the demo application


In the demonstration code of Chapter 1, Revisiting Multithreading, we looked at a simple c++11 application which used four threads to perform some processing. In this section, we will look at the same application, but from a hardware and OS perspective.

When we look at the start of the code in the main function, we see that we create a data structure containing a single (integer) value:

int main() {
    values.push_back(42);

After the OS creates a new task and associated stack structure, an instance of a vector data structure (customized for integer types) is allocated on the stack. The size of this was specified in the binary file's global data section (BSS for ELF).

When the application's execution is started using its entry function (main() by default), the data structure is modified to contain the new integer value.

Next, we create four threads, providing each with some initial data:

    thread tr1(threadFnc, 1);
    thread tr2(threadFnc, 2);
    thread tr3(threadFnc...