.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?

April 13, 2012 Apr 13, 2012 04/13/12

Stephen Toub - MSFT

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 ...

Is it ok to use nested Parallel.For loops?

March 14, 2012 Mar 14, 2012 03/14/12

Stephen Toub - MSFT

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 “owns ...

ThreadPool performance you can see

April 13, 2010 Apr 13, 2010 04/13/10

Stephen Toub - MSFT

We've spent a lot of time touting improvements to the .NET Framework in .NET 4 around threading, including core enhancements to the performance of the runtime itself. Sometimes data is more powerful than words, however, and it's useful to be able to see exactly what kind of difference such improvements can make. To assist with that...

ParallelExtensionsExtras Tour – #7 – Additional TaskSchedulers

April 9, 2010 Apr 9, 2010 04/9/10

Stephen Toub - MSFT

(The full set of ParallelExtensionsExtras Tour posts is available here.)In our last two ParallelExtensionsExtras blog tour posts, we’ve discussed two TaskScheduler implementations in ParallelExtensionsExtras: StaTaskScheduler and ConcurrentExclusiveInterleave. These are just 2 of more than 10 schedulers in ParallelExtensionsExtras...

PDC09 Parallelism Session Videos Now Available

November 21, 2009 Nov 21, 2009 11/21/09

Stephen Toub - MSFT

Attendees at PDC09 this past week were privy to quite a few sessions on parallel computing. Now that the videos of these sessions are online, you can view them as well from the comfort of your own home. Here are some of the key parallelism-related sessions from this past week:Overview Managed code in Visual Studio 2010...

Slides from Parallelism Tour

November 1, 2009 Nov 1, 2009 11/1/09

Stephen Toub - MSFT

Last week, I had the privilege of touring around Tennessee, Kentucky, Ohio, and Michigan, speaking about the new parallel computing support in Visual Studio 2010 and the .NET Framework 4. Many folks I spoke with were interested in getting a copy of the slide deck I used, so I’ve attached it to this blog post. Enjoy! ...

Task.Wait and “Inlining”

October 15, 2009 Oct 15, 2009 10/15/09

Stephen Toub - MSFT

“What does Task.Wait do?” Simple question, right? At a high-level, yes, the method achieves what its name implies, preventing the current thread from making forward progress past the call to Wait until the target Task has completed, one way or another. If the Task ran to completion, Wait will return successfully. ...

TaskScheduler.FromCurrentSynchronizationContext

September 22, 2009 Sep 22, 2009 09/22/09

Stephen Toub - MSFT

The Task abstractions in .NET 4 run on instances of the TaskScheduler class. Two implementations of TaskScheduler ship as part of the .NET Framework 4. The first is the default scheduler, which is integrated with the .NET 4 ThreadPool and takes advantage of its work-stealing queues. The second is the type of TaskScheduler ...

TaskCreationOptions.PreferFairness

July 7, 2009 Jul 7, 2009 07/7/09

Stephen Toub - MSFT

One of the ways in which the Task Parallel Library achieves good performance is through “work-stealing”. Work-stealing is supported in the .NET 4 ThreadPool for access through the Task Parallel Library and its default scheduler. This manifests as every thread in the ThreadPool having its own queue for work; when that ...

Tasks and Unhandled Exceptions

June 1, 2009 Jun 1, 2009 06/1/09

Stephen Toub - MSFT

Prior to the .NET Framework 2.0, unhandled exceptions were largely ignored by the runtime. For example, if a work item queued to the ThreadPool threw an exception that went unhandled by that work item, the ThreadPool would eat that exception and continue on its merry way. Similarly, if a finalizer running on the finalizer thread ...

.NET Parallel Programming

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