Async CTP 3 Presentation for MUGH 2012
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This document provides an overview of asynchronous programming using the async and await keywords introduced in C# 5, and the Task-based Asynchronous Pattern (TAP). It discusses earlier approaches to asynchronous programming that were disruptive and error-prone. The new approach uses tasks to represent ongoing asynchronous work, and the async and await keywords to allow asynchronous code to look synchronous. Key aspects covered include using the async modifier on methods, awaiting tasks, task states, cancellation, progress reporting, and building task-based combinators.
![a tour of
Asynchronous Programming
[Async CTP 3]](https://image.slidesharecdn.com/asyncpresentation-120418073421-phpapp02/85/Async-CTP-3-Presentation-for-MUGH-2012-1-320.jpg)
Async CTP 3 Presentation for MUGH 2012
- 1. a tour of Asynchronous Programming [Async CTP 3]
- 2. srikanth@brainscale.com/vishwanath.srikanth@gmail.com Vishwanath.srikanth Vishsrikanth Vishwanathsrikanth.wordpress.com Vishwanath Srikanth
- 3. Topics for this Presentation Earlier ways Awaiting Task Task based of Async asynchronously Programming We have features for every step of the way
- 4. EARLIER WAYS OF PROGRAMMING ASYNC
- 5. Async Programming Why do we need async? • Responsive UI. • Leverage Computing Power. • Better Utilization of Resources. • Better user experience. What is expected from Async programming patterns? • Transparent Remote operations • Easy to code • Cancellations, Timeouts, Preserving threads during blocking awaits etc.
- 6. Pre matured ways of async programming. Recommended Async Programming Concepts • Don’t wait for the response. • Return immediately after issuing a async request • Let the response call you back. Earlier ways • IAsyncResult Pattern Ex: BeginRead, EndRead • Event based Asynchronous pattern Sync Async
- 7. Pre matured ways of async programming. What went wrong? • Disruptive Program Structure • Error prone • Heavy weight • Difficult to design and write
- 8. New way of Async Programming DEMO
- 9. Awaiting a AWAITING TASK ASYNCHRONOUSLY Task
- 10. What is Async CTP? • A new language feature • New framework pattern What do you need to start working on Async CTP • Visual Studio 2011 Beta • Visual Studio 2010 SP1 with Async CTP Download from: http://www.microsoft.com/download/e n/details.aspx?id=9983
- 11. Task and Task<T> • A Task is a representation of ongoing work • Available in .NET 4 • Task returns nothing, Task<T> returns a result of type T. • Normal tasks - Independent of Thread. • Async tasks run on same thread. • Propagate Exceptions
- 12. ‘async’ modifier • Indicates Asynchrony • Can be used for methods or Events or Methods or Lambdas • Out and ref are not allowed. • Analogous to ‘yield’
- 13. ‘await’ keyword • Await - Prepend to a method which can return Task, Task<T> • Everything that continues is compiled asynchronously • ‘Async’ Runs synchronously until first ‘await’.
- 14. Task based Programming TASK BASED ASYNC PATTERN
- 15. Task based async pattern Async UI Thread Caller Method Task/Task<T> Create Task & Check for callback Wait for ‘await’ Load the Context Capture Context continue Sign up a call back.
- 16. Task Based Asynchronous Pattern (TAP) • Task Behavior – Initialization, Exceptions, Target Environment, TaskStatus • Task States • Created, WaitingForActivation, WaitingToRun, Running, WaitingForChildrenToComplete, RanToCompletion, Canceled, Faulted. • Cancellation • Cancellations • Progress Reporting • Testable • TaskID • Task Creation Options – None, Prefairness, LongRunning, AttachedToParent
- 17. Consuming the Task Based Asynchronous Pattern • Continue Await using continuewith • Task.Yield() • Cancel Context - ConfigureAwait • Cancellation • Cancellation.None • Progress Reporting
- 18. Building Task-Based Combinators Task.Run Task.WhenAll - Aggregate Exception or All Exceptions
- 19. Building Task-Based Combinators Task.FromResult Task.WhenAny • Redundancy • Interleaving • Throttling • Early bailout
- 20. Questions Thank you!
- 21. There is more…. Goodies…… • Which namespace does Task belongs to ? • Can we utilize the power of multicore using Tasks?