.NET Parallel Programming

All about Async/Await, System.Threading.Tasks, System.Collections.Concurrent, System.Linq, and more…

Await, SynchronizationContext, and Console Apps: Part 3

February 2, 2012 Feb 2, 2012 02/2/12

Stephen Toub - MSFT

In Part 1 and Part 2 of this short series, I demonstrated how you can build a SynchronizationContext and use it run an async method such that all of the continuations in that method will run on serialized on the current thread. This can be helpful when executing async methods in a console app, or in a unit test framework that doesn&rsquo...

Advanced APM Consumption in Async Methods

January 23, 2012 Jan 23, 2012 01/23/12

Stephen Toub - MSFT

I’ve previously blogged about how to expose existing Asynchronous Programming Model (APM) implementations as Task-based methods. This can be done manually using a TaskCompletionSource<TResult>, or it can be done using the built-in wrapper provided in TPL via the Task.Factory.FromAsync method. By creating a Task-based ...

Await, SynchronizationContext, and Console Apps: Part 2

January 21, 2012 Jan 21, 2012 01/21/12

Stephen Toub - MSFT

Yesterday, I blogged about how you can implement a custom SynchronizationContext in order to pump the continuations used by async methods so that they may be processed on a single, dedicated thread. I also highlighted that this is basically what UI frameworks like Windows Forms and Windows Presentation Foundation do with their message ...

Implementing a SynchronizationContext.SendAsync method

January 20, 2012 Jan 20, 2012 01/20/12

Stephen Toub - MSFT

I recently saw two unrelated questions, the answers to which combine to form a potentially useful code snippet.The first question was about SynchronizationContext. SynchronizationContext provides a Post method, which asynchronously schedules the supplied delegate and object state to be executed according to the SynchronizationContext&...

Await, SynchronizationContext, and Console Apps

January 20, 2012 Jan 20, 2012 01/20/12

Stephen Toub - MSFT

When I discuss the new async language features of C# and Visual Basic, one of the attributes I ascribe to the await keyword is that it “tries to bring you back to where you were.” For example, if you use await on the UI thread of your WPF application, the code that comes after the await completes should run back on that same UI ...

FAQ on Task.Start

January 14, 2012 Jan 14, 2012 01/14/12

Stephen Toub - MSFT

Recently I’ve heard a number of folks asking about Task.Start, when and when not to use it, how it behaves,and so forth. I thought I’d answer some of those questions here in an attempt to clarify and put to rest any misconceptions about what it is and what it does.1. Question: When can I use Task.Start?The Start instance ...

Awaiting Socket Operations

December 15, 2011 Dec 15, 2011 12/15/11

Stephen Toub - MSFT

The System.Net.Sockets.Socket class in .NET exposes multiple sets of asynchronous methods that perform the same basic operations but that are exposed with different patterns.The first set follows the APM pattern, where for a synchronous method like Receive, the BeginReceive and EndReceive methods are exposed. If you want to be able to &...

Coalescing CancellationTokens from Timeouts

December 3, 2011 Dec 3, 2011 12/3/11

Stephen Toub - MSFT

In the .NET Framework 4.5 Developer Preview, you’ll find that CancellationTokenSource now has timeout support built directly into its implementation. This makes it very easy to create a token that will automatically have cancellation requested after a particular time interval, e.g. public static CancellationToken FromTimeout(int ...

New in .NET 4.5: ThreadLocal.Values

November 10, 2011 Nov 10, 2011 11/10/11

Igor Ostrovsky - MSFT

Available since .NET 4, ThreadLocal<T> is a container that holds a separate value for every thread. In practice, ThreadLocal<T> is often convenient for storing per-thread counters, resources, or partial results. As mentioned earlier on this blog, we have been thinking about adding a Values property to enumerate over the values ...

PLINQ Queries That Run in Parallel in .NET 4.5

November 10, 2011 Nov 10, 2011 11/10/11

Igor Ostrovsky - MSFT

One interesting thing to know about PLINQ is that not all queries are guaranteed to execute in parallel (See PLINQ Queries That Run Sequentially for reference). You can think of the AsParallel method as a hint to run in parallel for query shapes that it believes will be faster. By default, PLINQ prefers to use a simple sequential algorithm ...

.NET Parallel Programming

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