Defrag Tools: #67 - Windows 8.1 - Background Task Hang

In this episode of Defrag Tools, Andrew Richards and Chad Beeder walk you through a common issues in Background Task applications. We use a Windows Store 8.1 app sample to show how missing code affects the process, and how the process can be reported as having an Application Hang due to non-responsiveness.

Resources:
Improving apps with Quality reports
Windows 8.1 Application Samples
Introduction to Background Tasks Whitepaper
Defrag Tools SkyDrive (inc. Scripts and ProcDumpExt)

Timeline:
[00:00] - Background Hangs in Windows Store apps
[00:54] - Quality reports - APPLICATION_HANG_...
[04:57] - Dump File - ".exr -1" - Exception Code 0xdfffffff
[06:50] - Background task sample
[11:24] - Missing IBackgroundTaskInstance::Canceled handler
[18:08] - Missing BackgroundTaskDeferral::Complete call
[19:39] - Email us your issues at defragtools@microsoft.com

--- EDIT ----

I looked in to Background Tasks more after taping:

• BackgroundTaskDeferral::Complete is required in all languages, not just C# as said.
• In JavaScript, a missing close() call on the web page causes the empty wwahost.exe, not a missing Complete call on the deferral (as I thought).

Note:
If you have a hang you don't understand, email the CAB file to defragtools@microsoft.com and we'll help you.