Concurrent programming and MEF

1. An overview of… Concurrent programming and MEF Luis Guerrero Plain Concepts http://www.luisguerrero.net http://geeks.ms/blogs/luisguerrero/

2. Parallel Programing in the .NET Framework

3. Why?

4. Searching for Parallelism • Finding exploitable parallelism • Organizing by Tasks • Organizing by Data • Organizing by Ordering

5. Organizing by Tasks • Linear or recursive? • Task parallel • Divide and conquer • Enough task? • Too many – thrashing • Too few – under utilization • Dependencies between tasks • Scheduling work to tasks

6. Organizing by Tasks • Work per task? • Small workloads • Variable workloads • Dependencies between tasks? • Removable • Separable • Read only or read/write

7. Organizing by Data • Linear or recursive? • Geometric decomposition • Recursive data • Data “chunk” size? • Too big – under utilization • Too small – trashing • Chunk layout? • Cache and cache line size • False cache sharing

8. Patterns for Parallelism • Implementation Patterns • Fork / Join • Loop Parallel • Divide and Conquer • Producer / Consumer • Pipeline • Asynchronous Agents

9. What’s about this talk? • Task Parallel Library • Parallel LINQ (PLINQ) • Data Structures for Parallel Programming • Parallel Diagnostic Tools

10. Task Parallel Library - Overview • Data parallelism: The Parallel Class • Parallel • For • For<> • Foreach • Invoke

11. Parallel class demo

12. Task – Overview • Task is the minimum unit of work in TPL • Can be scheduled by request • 2 Scheduled inside .NET box, ThreadPool y UI • Can have a result • Is observable • Can be continue with another task • Can be securely cancelled • Someone can wait for a completion

13. Creating Tasks demo

14. Task continuation demo

15. Exceptions and cancellation support demo

16. New System.Threading Primitives A Barrier is a synchronization primitive that enforces the stopping of execution between a number of threads or processes at a given point and prevents further execution until all threads or processors have reached the given point. A CountdownEvent is a synchronization primitive that enables ongoing tracking of a given workload in order to determine if processing of that workload is finished or not.

17. Barrier y CountdownEvent demo

18. PLINQ demo

19. An introduction to…. Managed Extensibility Framework (MEF)

20. Managed Extensibility Framework The Managed Extensibility Framework (MEF) is a new library in .NET 4 for building applications that can be incrementally extended. • For customers • For you and your team • Always there, always ready

21. Managed Extensibility Framework? The Managed Extensibility Framework (MEF) is a new library in the .NET Framework that enables greater reuse of applications and components. Using MEF, .NET applications can make the shift from being statically compiled to dynamically composed

22. What is “Extensibility”? In software engineering, extensibility is a systemic measure of the ability to extend a system and the level of effort required to implement the extension.

23. Open/Closed Principle Software entities should be open for extension, but closed for modification.

24. VS. Known Unknown

25. MEF Basics… • An Application is built of parts.

26. MEF Basics… • Export it. • Import it. • Compose it.

27. Export it. [Export(typeof(UserControl))] public class Widget1 : UserControl { public string Message { get{return(string) Button.Content;} set{Button.Content=value;} } } Widget1 UserControl Export

28. Import it. [Export(typeof(UserControl))] public class Widget1 : UserControl { [Import] public string Message { get{return(string) Button.Content;} set{Button.Content=value;} } } Widget1 String Import

29. Import it. [Export(typeof(UserControl))] public class Widget1 : UserControl { [Import(“HelloMEF.Message”)] public string Message { get{return(string) Button.Content;} set{Button.Content=value;} } } Widget1 “HelloMEF.Message” Import

30. Import it. [Export(typeof(UserControl))] public class MainPage: UserControl { [ImportMany(typeof(UserControl))] public IEnumerable<UserControl> { get;set; } } Main Page UserControl ImportMany

31. Compose it. PartIntializer: “Compose yourself” public MainPage() { InitializeComponent(); PartInitializer.SatisfyImports(this); } MainPage Compose

32. Where does the widget go? Widget Widget

33. Export it - Metadata [ExportMetadata(“Location”,Location.Top)] [Export(typeof(UserControl))] public class Widget1 : UserControl { public string Message { get{return(string) Button.Content;} set{Button.Content=value;} } } Widget1 Put me in the top UserControl Export

34. Import it - Metadata [Export(typeof(UserControl))] public class MainPage: UserControl { [ImportMany(typeof(UserControl))] public IEnumerable<Lazy<UserControl, IWidgetMetadata> { get;set; } } Main Page UserControl ImportMany

35. Export it - Metadata [ExportMetadata(“Location”,Location.Top)] [Export(typeof(UserControl))] public class Widget1 : UserControl { public string Message { get{return(string) Button.Content;} set{Button.Content=value;} } } Widget1 Put me in the top UserControl Export

36. Customize it – Custom exports [Widget(Location=Location.Top)] public class Widget1 : UserControl { public string Message { get{return(string) Button.Content;} set{Button.Content=value;} } } Widget1 Put me in the top UserControl Export

37. Container is the Match Maker Container

38. Catalogs provide Parts Container Catalog

39. Catalogs provide Parts TypeCatalog Container AssemblyCatalog DirectoryCatalog Catalog AggregatingCatalog

40. Parts can be lazy… [Import(typeof(ILogger))] public ILoggerExport<ILogger> Logger { get; set; } Part B Export <A>

41. Lifetime On Export [CompositionOptions(CreationPolicy=CreationPolicy.NonShared)] [CompositionOptions(CreationPolicy=CreationPolicy.Shared)] On Import [Import(RequiredCreationPolicy=CreationPolicy.NonShared)] [Import(RequiredCreationPolicy=CreationPolicy.Shared)] Shared Non-Shared Container Container Part A Part B Part B Part B