Book Image

Mastering C# Concurrency

Book Image

Mastering C# Concurrency

Overview of this book

Starting with the traditional approach to concurrency, you will learn how to write multithreaded concurrent programs and compose ways that won't require locking. You will explore the concepts of parallelism granularity, and fine-grained and coarse-grained parallel tasks by choosing a concurrent program structure and parallelizing the workload optimally. You will also learn how to use task parallel library, cancellations, timeouts, and how to handle errors. You will know how to choose the appropriate data structure for a specific parallel algorithm to achieve scalability and performance. Further, you'll learn about server scalability, asynchronous I/O, and thread pools, and write responsive traditional Windows and Windows Store applications. By the end of the book, you will be able to diagnose and resolve typical problems that could happen in multithreaded applications.
Table of Contents (17 chapters)
Mastering C# Concurrency
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Exception handling


Another important aspect of TPL is working with exceptions. Just as the normal code that we write can generate an exception, so can the code inside a TPL task. Since every task has its own stack, we cannot work with exceptions in the usual way. TPL has several options that allow us to work with exceptions in a parallel program.

The easiest option is to check the task status. If an exception has been raised inside the task, it will have the Status property set to TaskStatus.Faulted. The exception will be available through the Task.Exception property:

var task = Task.Factory.StartNew(() =>
{
  throw new ApplicationException("Test exception");
});

while (!task.IsCompleted) {}

Console.WriteLine("Status = {0}", task.Status);
Console.WriteLine(task.Exception);

This code prints the following:

Status = Faulted

System.AggregateException: One or more errors occurred. ---> System.ApplicationException: Test exception
...

The original exception that has been thrown in the code...