1660950 - Repair "Shutdown hanging before starting" crash reports

Status: RESOLVED FIXED

(Toolkit :: Async Tooling, defect, P2)

Description

[Jens Stutte [:jstutte]]

Looking at crashes generated by RunWatchDog's timeout reporting, I was wondering why we do not see any "Shutdown hanging at step %s. " messages but only the (somewhat misleading) "Shutdown hanging before starting." message.

It seems, we rely on sShutdownSteps[i].mTicks > -1 in order to determine during reporting if a step has been ever worked on. The only place I see where mTicks is set seems to be here, where we explicitly exclude to ever set the first step's ticks to something. This makes us always break from the loop in the reporting function at the first entry. I ignore, if there is any rationale to not set mTicks for sShutdownSteps[0], though.

Comment 1

[Jens Stutte [:jstutte]]

Attachment: Bug 1660950 - make shutdown steps reporting work

Comment 2

[Jens Stutte [:jstutte]]

I can see no reason to not set also mTicks for the first shutdown step.

Comment 3

[Simon Giesecke [:sg] [he/him]]

Right now, we have lots of reports claiming "Shutdown hanging before starting": https://crash-stats.mozilla.org/search/?moz_crash_reason_raw=MOZ_CRASH%28Shutdown%20hanging%20before%20starting.%29&product=Firefox&date=%3E%3D2020-08-18T09%3A44%3A00.000Z&date=%3C2020-08-25T09%3A44%3A00.000Z&_facets=signature&_sort=-date&_columns=date&_columns=signature&_columns=product&_columns=version&_columns=build_id&_columns=platform#facet-signature

Comment 4

[Jens Stutte [:jstutte]]

Yes, this patch potentially affects quite some signatures.
Edit: The MOZ_CRASH_REASON of these signatures will probably change all.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5cf9e8cdb828
make shutdown steps reporting work r=smaug

Comment 6

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/5cf9e8cdb828

Comment 7

[Jens Stutte [:jstutte]]

Comment on attachment 9171876 [details]
Bug 1660950 - make shutdown steps reporting work

Beta/Release Uplift Approval Request

• User impact if declined: End user impact none, but we would continue to receive bogus crash reports for shutdown hangs.
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: No
• If yes, steps to reproduce: We have no STR for shutdown hangs.
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): It just changes the way the moz crash reason message we report is generated.
• String changes made/needed:

Comment 8

[Julien Cristau [:jcristau]]

Comment on attachment 9171876 [details]
Bug 1660950 - make shutdown steps reporting work

approved for 81.0b3

Comment 9

[Jens Stutte [:jstutte]]

There seem to be a first report with the new message.

Comment 10

[Julien Cristau [:jcristau]]

https://hg.mozilla.org/releases/mozilla-beta/rev/6a779ef49193