MICROSOFT WINDOWS 8 BUILD STUDY NOTE (4)

HW-59T - Improving performance with the Windows Performance Toolkit

refer: http://channel9.msdn.com/Events/BUILD/BUILD2011/HW-59T

Note:

• Motivation for performance analysis:

  • Performance related to multiple layered impact such as : hardware, OS, other application and process impact.

• Stage of performance improvement:

  • Preception –> Measurement –> Analysis.

  • It will be back and forth after analysis and re-preception.

• Tool list:

  • Trace Capture: Windows Performance Recorder

  • Tacce Analysis: Windows Performance Analizer

• Things to look out:

  • Don’t assume you know what’s wrong.

  • Don’t enable too much instrumentation

  • Don’t trace longer than you need.

PLAT-203T Async everywhere: creating responsive APIs & apps

refer: http://channel9.msdn.com/Events/BUILD/BUILD2011/PLAT-203T

Note:

• Async only support on some API:

  • XAML, Tile on UI

  • GPS and portable debice on Device

  • All network and communicate

  • Applifetime, Authentication, Crytography on Fundamental

• Await

  • Await is a simple way to against async API.

  • Await will make the async highest priority and let the compiler know here need to wait the result come back. Code will run as sequencial.

• Error handling

try { FileOpenPicker p = new FileOpenPicker(); p.FileTypeFilter.Add(".jpg");ry var operation = p.PickSingleFileAsync(); operation.Completed = (IAsyncOperation f) => { MyButton.Content = f.GetResults().FileName; }; operation.Start(); catch(...) {}</blockquote> * try catch will only cover RED one, it need refine code to cover whole scope

try { FileOpenPicker p = new FileOpenPicker(); p.FileTypeFilter.Add(".jpg"); MyButton.Content = (await p.PickSingleFileAsync()).FileName; } catch(Exception e) {}

* It will separate into “RED” and “Green” one but still cover on try catch. * 5 top tips from presenter. * Don’t worry about the COM apartment. * Remember to start your operation. * File picker cancel != Async Cancel * It will complete but return NULL. * “use exception for exceptional things” * Don’t worry about Dispatcher.Invoke… * Don’t worry about the concurrency Refer: [http://blogs.msdn.com/b/ericlippert/archive/2010/10/29/asynchronous-programming-in-c-5-0-part-two-whence-await.aspx](http://blogs.msdn.com/b/ericlippert/archive/2010/10/29/asynchronous-programming-in-c-5-0-part-two-whence-await.aspx)