Async Code Wrangling

Introduction to making your code asynchronous. Demo C# code available via GitHub repo (https://github.com/patridge/demos-asynchronous-csharp/). Demo code was entirely live-coded, but the repo expresses all the same concepts.

Transcript

1. Async Let your code do the waiting, not your user. @patridgedev patridgedev.com
3. Async vs. Parallel Parallel for speed. Async for responsiveness.
4. Async when? • Network access • File access • Accessing anything slow/unreliable • Animations • User interactions
5. Callbacks are fun getSomething(function (result1) { processResult(function (result2) { getSomethingElse(function (result3) { // Now do something useful with final result. }); }); });
6. Promises[/Deferreds/Tasks] An interface for working with a value without knowing (or caring) what it will be, where it will come from, or even if it will come back successfully.
7. Why promises? • Easier code control flow • Easier error handling • Decouples from time
8. Async in .NET .NET 1.0: Async Pattern (Begin/End) .NET 2.0: Event-based Async Pattern (Callback) .NET 4.0: Task Parallel Library .NET 4.5: async/await
9. Demo 1 Getting your code to be asynchronous… Handling asynchronous errors...
10. C# async/await Another layer beyond Tasks. Makes it easier to write asynchronous code. Compiler handles all the magic for you.
11. Demo 2 Incorporating async/await...
12. Other Resources • Lucian Wischik's blog/videos (blogs.msdn.com/b/lucian/) • MSDN: Best Practices in Asynchronous Programming (http://msdn.microsoft.com/en-us/magazine/jj991977. aspx) • Various TechEd/Build talks on Channel9 • Microsoft Async for async/await in VS 2012 (https: //www.nuget.org/packages/Microsoft.Bcl.Async) @patridgedev patridgedev.com
13. Bonus Demo 1 async/await the user interaction...
14. Bonus Demo 2 Interacting with legacy code asynchronously