.NET Parallel Programming

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

Should I expose synchronous wrappers for asynchronous methods?
Should I expose synchronous wrappers for asynchronous methods?
In a previous post Should I expose asynchronous wrappers for synchronous methods?, I discussed “async over sync,” the notion of using synchronous functionality asynchronously and the benefits that doing so may or may not yield. The other direction of “sync over async” is also interesting to explore. Avoid Exposing ...
Async/Await FAQ
Async/Await FAQ
From time to time, I receive questions from developers which highlight either a need for more information about the new “async” and “await” keywords in C# and Visual Basic. I’ve been cataloguing these questions, and I thought I’d take this opportunity to share my answers to them.Conceptual OverviewWhere can ...
Are deadlocks still possible with await?
Are deadlocks still possible with await?
Developers familiar with parallel programming are also familiar with a wide range of potential problems that can occur when practicing the art.  One of the most well-known issues is “deadlock,” where two or more operations are waiting on each other to complete in a manner such that none of them will be able to complete.I&rsquo...
Overriding Stream Asynchrony
Overriding Stream Asynchrony
In .NET 4.5 Beta, the Stream class provides multiple virtual methods related to reading and writing: As a developer deriving from Stream, it’s helpful to understand what the base implementations do and when you can and should override them.Read, Write, FlushThe Read, Write, and Flush methods are the core synchronous ...
Do I need to dispose of Tasks?
Do I need to dispose of Tasks?
I get this question a lot: “Task implements IDisposable and exposes a Dispose method.  Does that mean I should dispose of all of my tasks?” SummaryHere’s my short answer to this question: “No.  Don’t bother disposing of your tasks.”Here’s my medium-length answer: “No.  Don&...
Should I expose asynchronous wrappers for synchronous methods?
Should I expose asynchronous wrappers for synchronous methods?
Lately I’ve received several questions along the lines of the following, which I typically summarize as “async over sync”: In my library, I have a method “public T Foo();”.  I’m considering exposing an asynchronous method that would simply wrap the synchronous one, e.g. “public Task<T> ...
Is it ok to use nested Parallel.For loops?
Is it ok to use nested Parallel.For loops?
Every now and then, I get this question: “is it ok to use nested Parallel.For loops?” The short answer is “yes.”  As is often the case, the longer answer is, well, longer. Typically when folks ask this question, they’re concerned about one of two things.  First, they’re concerned that each nested loop will assume it “...
Are you using TPL Dataflow?  We’d love to know!
Are you using TPL Dataflow? We’d love to know!
Are you using the new System.Threading.Tasks.Dataflow.dll library, either from its CTPs or from the .NET 4.5 Developer Preview or Beta?  We'd love to hear about it, and if you have time, what your experiences have been (good or bad).  What kind of solution are you building, and how are you using TPL Dataflow in it?  Has the ...