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

MPI communication


At this point, we have a functional MPI cluster, which can be used to execute MPI-based applications (and others, as well) in a parallel fashion. While for some tasks it might be okay to just send dozens or hundreds of processes on their merry way and wait for them to finish, very often it is crucial that these parallel processes are able to communicate with each other.

This is where the true meaning of MPI (being "Message Passing Interface") comes into play. Within the hierarchy created by an MPI job, processes can communicate and share data in a variety of ways. Most fundamentally, they can share and receive messages.

An MPI message has the following properties:

  • A sender
  • A receiver
  • A message tag (ID)
  • A count of the elements in the message
  • An MPI datatype

The sender and receiver should be fairly obvious. The message tag is a numeric ID which the sender can set and which the receiver can use to filter messages, to, for example, allow for the prioritizing of specific messages. The...