Asynchronous Programming Tips and Tricks in .NET

Transcript

1. Asynchronous Programming Tips and Tricks in .NET Tugberk Ugurlu tugberkugurlu.com @tourismgeek
2. Agenda • Refresh on Asynchronous Programming Models on .NET • High level overview of async/await keywords • Tips and Tricks on TPL + async/await usage and scenarios
3. Assumptions • Knowledge on C# (duh!) • Prior Knowledge on Asynchronous Programming • Prior Knowledge on TPL (Task Parallel Library)
5. Asynchronous Programming Models in .NET • Asynchronous Programming Model (APM) • Event-based Asynchronous Pattern (EAP) • Task-Based Asynchronous Pattern (TAP)
6. Asynchronous Programming Model (APM)
7. Event-based Asynchronous Pattern (EAP)
8. Task-Based Asynchronous Pattern (TAP)
9. async/await and its glory
10. async/await and its glory For more information, check out: "Easy Asynchrony with C#: No More Callbacks! (http://bit.ly/1FEoK85)" talk by Mads Torgersen
11. Make Use of Pre Completed Tasks
12. Make Use of Pre Completed Tasks DON’T
13. Make Use of Pre Completed Tasks DON’T
14. Make Use of Pre Completed Tasks DO
15. Make Use of Pre Completed Tasks DO
16. DON’T await on Task.FromResult
17. DON’T await on Task.FromResult DON’T
18. Directly Return the Task “Generally, if you are not going to be running any continuation in a method which consumes a Task returning code, don’t await on the Task”
19. Directly Return the Task DON’T
20. Directly Return the Task DO
21. Don’t Wrap Thread Offloading Work “Library methods should not lie. If it looks async in its signature, it should be async in its implementation.” - Lucian Wischik https://channel9.msdn.com/Series/Three-Essential-Tips-for-Async/Async-Library-Methods-Shouldn-t-Lie
22. Don’t Wrap Thread Offloading Work DON’T
23. ConfigureAwait(false) http://channel9.msdn.com/Events/BUILD/BUILD2011/TOOL-829T
24. ConfigureAwait(false) General rule of thumb: “When you are awaiting inside a library code, you should never care about SynchronizationContext and call ConfigureAwait(false)”
25. ConfigureAwait(false) DON’T
26. Task.WhenAll(Task[])
27. Task.WhenAll(Task[]) “Be careful on how you do parallelization on server, refer to "How and Where Concurrent Asynchronous I/O with ASP.NET Web API (http://bit.ly/1NwGp5I)" for more information about this”
28. There are MORE! • Six Essential Tips for Async: http://bit.ly/1ynpoEm • Async best practices: http://bit.ly/1DsFuMi • Async Performance: http://bit.ly/1EqWYdy • My Async Blog Posts: http://tugberkugurlu.com/tags/async • The zen of async: http://bit.ly/1NyIdvb
29. Resources • Slides: http://bit.ly/1CHNJzT • Source Code: https://github.com/tugberkugurlu/AsyncTips