View source for Hang Detector and Reporter:/Test Plan

= Hang Detector and Reporter =

{| class="fullwidth-table"
|-
| Feature 
| Status 
| Lead engineer 
| QA Lead 
| Status
|-
| Hang Detector and Reporter
| {{StatusHealthy|status=Development in progress}}
| Vladan Djeric
| Simona Badau
| {{StatusHealthy|status= OK}}
|}

== Summary ==
* The Hang Reporter feature - reports transient main thread hangs to Telemetry.
* It relies on having Firefox compiled with frame pointers to unwind call stacks and because of this it is only useful on Windows builds from the Profiling branch.
* The Hang Reporter functionality is #ifdef'd out on regular release builds.
* It will not be enabled in release builds and the intended audience is Firefox developers.

'''Demo of the functionality:'''
The minimum steps to see a demo of the functionality is to set up the profiling Nightly and  the Symbolication Server locally.

How to set up the profiling Nightly:<br>
1. Install the profiling link from [https://people.mozilla.com/~vdjeric/firefox-14.0a1.en-US.win32.installer.exe here]<br>
2. Go to Help menu -> Options -> Advanced -> Update -> enable the option to 'Never check for updates' -> OK<br>
3. Go to Help menu -> Options -> Advanced -> General -> enable the option to 'Submit performance data'.<br>
4. Install the custom [https://people.mozilla.com/~vdjeric/ping.telemetry.xpi about:telemetry add-on]<br>

How to set up the Symbolication Server:<br>
Prerequisites:<br>
Install [http://code.google.com/p/msysgit/, Git for Windows] or Cygwin and [http://www.activestate.com/activepython/downloads, Python] or Cygwin.

5. Download some of the symbols for Nightly profiling build by extracting the [https://people.mozilla.com/~vdjeric/symbols_ffx.zip, zip] locally.<br> 
6. Run “git clone git://github.com/vdjeric/Snappy-Symbolication-Server.git” in Windows command line.<br>
7. Edit the Snappy Symbolication Server’s “sample.conf” file:<br>
* the firefoxSymbolsPath and the osSymbolsPath have to point to the “symbols_ffx” directory downloaded in step 5.<br>
8.  Run the symbolication server locally with the command “python symbolicationWebService.py sample.conf”.<br>
9. To see the hang stacks go to your profiling Nightly -> in about config enable the pref toolkit.telemetry.enabled to true -> navigate to about:telemetry page -> click on 'Force Hang' button -> reload the page and click on the 'Symbolicate Stacks' button.<br>

The stack should look like this:

<tt><u>'''Hang report #1 (18 seconds):'''<br/></u>
??? (in ntdll.dll)<br>
PRMJ_Now (in mozjs.dll)<br>
js_Date(JSContext *,unsigned int,JS::Value *) (in mozjs.dll)<br>
???<br>
???<br></tt>

Note that:
* the minimum interval for capturing a hang is 10 seconds;
* the value of the hang can be changed in about:config via the preference hangmonitor.timeout;

== References ==

*[https://wiki.mozilla.org/Hang_Detector_and_Reporter: Wiki page]
*[http://blog.mozilla.com/vdjeric/ blog mozilla.com]

== Use Cases ==

* Check the hang stacks:
** having the telemetry disabled or the hangmonitor.timeout pref set to zero;
** having the telemetry enabled or the hangmonitor.timeout pref set to zero;
** having the telemetry disabled or the hangmonitor.timeout pref set to non-zero;
** having the telemetry enabled or the hangmonitor.timeout pref set to non-zero;

== Test Cases ==
*The test cases for this feature can be viewed [http://bit.ly/yDdhxZ here].

== Important Bugs ==

*[https://bugzilla.mozilla.org/show_bug.cgi?id=712109 712109] -  Implement non-fatal chromehang by turning on frame-pointers on a branch 

== Not Tested ==

* TBD

== Sign off Criteria ==

*All the test cases were executed.
*All the major bugs have been fixed.