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

Making a thread wait


This recipe will show you how a program can wait for some computation in another thread to complete to use its result later in the code. It is not enough to use Thread.Sleep because we don't know the exact time the computation will take.

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\Recipe3.

How to do it...

To understand how a program can wait for some computation in another thread to complete to use its result later, 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...");
    Thread t = new Thread(PrintNumbersWithDelay);
    t.Start();
    t.Join();
    Console.WriteLine("Thread completed");
  5. Run the program.

How it works...

When the program is run, it runs a long-running thread that prints out numbers and waits two seconds before printing each number. But in the main program, we called the t.Join method, which allows us to wait for thread t to complete. When it is complete, the main program continues to run. With the help of this technique, it is possible to synchronize execution steps between two threads. The first one waits until another one is complete and then continues to work. While the first thread is waiting, it is in a blocked state (as it is in the previous recipe when you call Thread.Sleep).