The document discusses parallel extensions to the .NET framework. It introduces the Task Parallel Library (TPL) as a new way to write multi-threaded code using tasks instead of threads directly. The TPL uses tasks and asynchronous operations to simplify parallel programming and allow the system to optimize workload distribution. It also discusses Parallel LINQ (PLINQ) for parallelizing LINQ queries and higher level constructs like Parallel.For that build on TPL.

1. Parallel Extensions to the .NET Framework Mike Taulty Developer & Platform Group Microsoft Ltd [email_address] http://www.mtaulty.com

2. Buying a new Processor £100 - £300 2-3GHz 2 cores or 4 64-bit Core Core

3. Buying a new Processor Core Core Core Core £200 - £500 2-3GHz 4 cores with HT 64-bit QuickPath Interconnect Memory Controller

4. Where will it all end? Unisys ES7000 (7600R) used with kind permission of Mr Henk var der Valk, Unisys, NL

5. “ I’ll have a big one, please”

6. Was it a wise purchase? Windows OS App 1 App 2 ... App 1 .NET CLR .NET Framework My Code

9. Parallel sums on ThreadPool

12. Parallel Sums Revisited

13. Parallel Extensions to .NET System.Threading System.Collections.Concurrent System.dll System.Linq System.Linq.Parallel System.Core.dll System.Threading.Tasks System.Threading System.Collections.Concurrent System.Threading.Internal mscorlib.dll

14. Task Parallel Library ( TPL ) Task TaskFactory TaskScheduler Key Classes

15. Starting with Task

16. Starting with Task

17. Exploring Task

18. Exploring Task

19. Scheduling Tasks TaskScheduler Task ThreadPoolTaskScheduler SynchronizationContext TaskScheduler Custom QueueTask(Task t)

20. Picking/Building a Scheduler

21. Default Scheduling .NET ThreadPool ( with V4.0 modifications ) … Thread Thread Thread Work Item Work Item Work Item Work Item Thread’s Work Queue Thread’s Work Queue Thread’s Work Queue Work Item Work Item Work Item Global Work Queue

22. Task Exotica ( knobs )

23. Task exotica

25. Parallel.Invoke, ForEach, For

26. Parallel LINQ ( PLINQ ) Select() Where() Etc. Extension method in System.LINQ Extends IEnumerable<T> LINQ to Objects LINQ to XML not LINQ to SQL,EF Results in a ParallelQuery<T> “ Usually” would be Enumerable

27. Parallel LINQ ( PLINQ ) IEnumerable<T> Could be IList<T> or Array Range Chunk Striped? Hash “ Where” “ Where” “ Where” “ OrderBy” “ OrderBy” “ OrderBy” “ Sum” “ Sum” “ Sum” Consumer( foreach … ) Merge Re-partition Task Task Task Query Query Query Partition

29. PLINQ

30. Co-ordination Data Structures

31. Co-ordination Data Structures

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