.NET Parallel Programming

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

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 ...

ConcurrentDictionary Performance Improvements in .NET 4.5

November 8, 2011 Nov 8, 2011 11/8/11

Igor Ostrovsky - MSFT

ConcurrentDictionary is a popular concurrent data structure that was introduced in .NET 4. In the .NET 4.5 release, ConcurrentDictionary gets two performance improvements. One optimization is related to the way ConcurrentDictionary avoids torn reads and writes. To explain the background, all reference types and some value types are guaranteed...

What’s New For Parallelism in .NET 4.5

September 17, 2011 Sep 17, 2011 09/17/11

Stephen Toub - MSFT

.NET 4 and Visual Studio 2010 saw the introduction of a wide range of new support for parallelism: the Task Parallel Library (TPL), Parallel LINQ (PLINQ), new synchronization and coordination primitives and collections (e.g. ConcurrentDictionary), an improved ThreadPool for handling parallel workloads, new debugger windows, new concurrency ...

Parallel Merge Sort using Barrier

June 6, 2011 Jun 6, 2011 06/6/11

Emad Omara

Sorting is one of the most fundamental problems in software algorithms; there are many sequential sorting algorithms with different time and memory complexities, but when it comes to parallel sort, things get more complicated. I will explain a simple and scalable algorithm to write a parallel sort using the .NET 4.0 System.Threading.Barrier ...

Little-known gems: Atomic conditional removals from ConcurrentDictionary

April 2, 2011 Apr 2, 2011 04/2/11

Stephen Toub - MSFT

ConcurrentDictionary<TKey,TValue>, first introduced in .NET 4, is an efficient dictionary data structure that enables thread-safe reading and writing, meaning that multiple threads may all be accessing the dictionary at the same time without corrupting it. It supports adding through its TryAdd method, conditional updates through ...

SpinWait.SpinUntil for unit testing

February 15, 2011 Feb 15, 2011 02/15/11

Stephen Toub - MSFT

One of the hidden gems in .NET 4 is the System.Threading.SpinWait type. This type is typically used for implementing lock-free solutions, and is used heavily throughout the rest of the threading and parallelism support in .NET 4. That’s why I call it “hidden”, because most folks don’t implement their own ...

New Feature? :: ThreadLocal.Values

October 21, 2010 Oct 21, 2010 10/21/10

Danny Shih

We’ve been considering adding a Values property to System.Threading.ThreadLocal<T>. Values would return a collection of all current values from all threads (e.g. what you’d get if you evaluated Value from each thread). This would allow for easy aggregations, and in fact in our Parallel Extensions Extras we have a ...

Using Cancellation Support in .NET Framework 4

July 2, 2010 Jul 2, 2010 07/2/10

Igor Ostrovsky - MSFT

The .NET Framework 4 introduces a new mechanism for cancellation of operations, based on new types CancellationToken and CancellationTokenSource. This cancellation mechanism is used across the parallel programming libraries: tasks, concurrent collections, and PLINQ queries.Using Cancellation Support in .NET Framework 4, written by ...

Lesser-known Multi-threaded Debugging Support in Visual Studio 2010

May 25, 2010 May 25, 2010 05/25/10

Stephen Toub - MSFT

We’ve been very excited about the new debugging windows in Visual Studio 2010, namely Parallel Tasks and Parallel Stacks, as well as the newly revamped Threads window, and thus we’ve talked about them quite a bit. For an overview, you can read the MSDN Magazine article at https://msdn.microsoft.com/en-us/magazine/ee410778.aspx, and Daniel ...

ParallelExtensionsExtras Tour – #14 – SingleItemPartitioner

April 28, 2010 Apr 28, 2010 04/28/10

Stephen Toub - MSFT

(The full set of ParallelExtensionsExtras Tour posts is available here.) In a previous ParallelExtensionsExtras Tour blog post, we talked about implementing a custom partitioner for BlockingCollection<T>. Custom partitioning is an advanced but important feature supported by both Parallel.ForEach and PLINQ, as it allows the ...

.NET Parallel Programming

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