1251895 - Frequent crashes [@ PL_HashTableRawLookup][@ GetSerialNumber] when getting stacks for leaks in automation

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Ryan VanderMeulen [:RyanVM]]

I've been trying to get stacks for the various intermittent leaks we currently have and am seeing a pretty frequent crash that appears to be in the stack getting code itself.

https://treeherder.mozilla.org/logviewer.html#?job_id=17321578&repo=try
https://treeherder.mozilla.org/logviewer.html#?job_id=17321964&repo=try

Comment 1

[Nathan Froyd [:froydnj]]

Do you have a set of tests/chunks that you frequently run to get this?

Are you trying to log specific object types or object IDs when you do this?  We shouldn't even be touching GetSerialNumber if we're not logging specific things...

Comment 2

[Ryan VanderMeulen [:RyanVM]]

They're pretty widespread. Take a look at my recent Try history.
https://treeherder.mozilla.org/#/jobs?repo=try&author=[e-mail]&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-resultStatus=runnable&fromchange=96b972ba996b

Comment 3

[Nathan Froyd [:froydnj]]

Ah, trying to log particular objects on all of those.  I think I understand what's going on here; I'll try to put together a patch on Monday.

Comment 4

[Nathan Froyd [:froydnj]]

Attachment: don't race on nsTraceRefcnt's object serial number tables

I think this solves Ryan's crashes (try run in progress): GetSerialNumber is
accessing global state, sometimes accessed under a lock (for logging
AddRef/Release) and sometimes not (for logging COMPtr AddRef/Release).  We
should be accessing it under the lock all the time...

Comment 5

[Andrew McCreight [:mccr8]]

Comment on attachment 8724884 [details] [diff] [review]
don't race on nsTraceRefcnt's object serial number tables

Review of attachment 8724884 [details] [diff] [review]:
-----------------------------------------------------------------

Yikes!

Comment 6

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/b0d4a61fc0f0

Comment 7

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/b0d4a61fc0f0