Showing results for async - .NET Blog

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’t di...

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 wrapper...

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 pumps.N...

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’s ...

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 thread. ...

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 “...

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 millise...

Imagine that you have a Task handed to you by a third party, and that you would like to force this Task to complete within a specified time period. However, you cannot alter the “natural” completion path and completion state of the Task, as that may cause problems with other consumers of the Task. So you need a way to obtain a copy or “proxy” of th...

In April, we released the Async CTP Refresh, and since then we've seen fantastic adoption of the technology.  We've also seen the technology landscape evolve.  Windows Phone 7.5, aka "Mango", was released.  Silverlight 5 has had both a Beta and an RC release.  And there have been multiple patches to Visual Studio and the .NET Fr...

When you start using async methods heavily, you’ll likely see a particular pattern of composition pop up from time to time.  Its structure is typically either of the form: async Task FooAsync() {     … // some initialization code without awaits      await BarAsync(…); ...