Blog E

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<StorageFile> f) =>

  {

  MyButton.Content = f.GetResults().FileName;

  };

  operation.Start();

  catch(…) {}

  • 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