Book Image

Multithreading in C# 5.0 Cookbook

By : Evgenii Agafonov
Book Image

Multithreading in C# 5.0 Cookbook

By: Evgenii Agafonov

Overview of this book

In an age when computer processors are being developed to contain more and more cores, multithreading is a key factor for creating scalable, effective, and responsive applications. If you fail to do it correctly, it can lead to puzzling problems that take a huge amount of time to resolve. Therefore, having a solid understanding of multithreading is a must for the modern application developer. Multithreading in C# 5.0 Cookbook is an easy-to-understand guide to the most puzzling programming problems. This book will guide you through practical examples dedicated to various aspects of multithreading in C# on Windows and will give you a good basis of practical knowledge which you can then use to program your own scalable and reliable multithreaded applications. This book guides you through asynchronous and parallel programming from basic examples to practical, real-world solutions to complex problems. You will start from the very beginning, learning what a thread is, and then proceed to learn new concepts based on the information you get from the previous examples. After describing the basics of threading, you will be able to grasp more advanced concepts like Task Parallel Library and C# asynchronous functions. Then, we move towards parallel programming, starting with basic data structures and gradually progressing to the more advanced patterns. The book concludes with a discussion of the specifics of Windows 8 application programming, giving you a complete understanding of how Windows 8 applications are different and how to program asynchronous applications for Windows 8.
Table of Contents (18 chapters)
Multithreading in C# 5.0 Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Aborting a thread


In this recipe, we will describe how to abort another thread's execution.

Getting ready

To work through this recipe, you will need Visual Studio 2012. There are no other prerequisites. The source code for this recipe can be found at BookSamples\Chapter1\Recipe4.

How to do it...

To understand how to abort another thread's execution, perform the following steps:

  1. Start Visual Studio 2012. Create a new C# Console Application project.

  2. In the Program.cs file, add the following using directives:

    using System;
    using System.Threading;
  3. Add the following code snippet below the Main method:

    static void PrintNumbersWithDelay()
    {
      Console.WriteLine("Starting...");
      for (int i = 1; i < 10; i++)
      {
        Thread.Sleep(TimeSpan.FromSeconds(2));
        Console.WriteLine(i);
      }
    }
  4. Add the following code snippet inside the Main method:

    Console.WriteLine("Starting program...");
    Thread t = new Thread(PrintNumbersWithDelay);
    t.Start();
    Thread.Sleep(TimeSpan.FromSeconds(6));
    t.Abort();
    Console.WriteLine("A thread has been aborted");
    Thread t = new Thread(PrintNumbers);
    t.Start();
    PrintNumbers();
  5. Run the program.

How it works...

When the main program and a separate number-printing thread run, we wait for 6 seconds and then call a t.Abort method on a thread. This injects a ThreadAbortException method into a thread causing it to terminate. It is very dangerous, generally because this exception can happen at any point and may totally destroy the application. In addition, it is not always possible to terminate a thread with this technique. The target thread may refuse to abort by handling this exception and calling the Thread.ResetAbort method. Thus, it is not recommended that you use the Abort method to close a thread. There are different methods that are preferred, such as providing a CancellationToken method to cancel a thread execution. This approach will be described in Chapter 3, Using a Thread Pool.