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

Static order of initialization


Static variables are variables which are declared only once, essentially existing in a global scope, though potentially only shared between instances of a particular class. It's also possible to have classes which are completely static:

class Foo { 
   static std::map<int, std::string> strings; 
   static std::string oneString; 
 
public: 
   static void init(int a, std::string b, std::string c) { 
         strings.insert(std::pair<int, std::string>(a, b)); 
         oneString = c; 
   } 
}; 
 
 
std::map<int, std::string> Foo::strings; 
std::string Foo::oneString; 

As we can see here, static variables along with static functions seem like a very simple, yet powerful concept. While at its core this is true, there's a major issue which will catch the unwary when it comes to static variables and the initialization of classes. This is in the form of initialization order.

Imagine what happens if we wish to use the preceding class from another class...