1029504 - WebGL assertion failure: "observerService" [@ mozilla::WebGLObserver::UnregisterMemoryPressureEvent()]

Status: RESOLVED FIXED

(Core :: Graphics: CanvasWebGL, defect)

Description

[Benoit Jacob [:bjacob] (mostly away)]

Currently seen intermittently on linux x86-64 mochitest-2

https://tbpl.mozilla.org/?tree=Mozilla-Inbound&rev=5a8e5ad43d90

Brief log:

https://tbpl.mozilla.org/php/getParsedLog.php?id=42351778&tree=Mozilla-Inbound#error3

05:33:13     INFO -  Assertion failure: observerService, at /builds/slave/m-in-l64-d-0000000000000000000/build/content/canvas/src/WebGLContext.cpp:158

05:33:21     INFO -  Crash reason:  SIGSEGV
05:33:21     INFO -  Crash address: 0x0
05:33:21     INFO -  Thread 0 (crashed)
05:33:21     INFO -   0  libxul.so!mozilla::WebGLObserver::UnregisterMemoryPressureEvent() [WebGLContext.cpp:5a8e5ad43d90 : 158 + 0x1f]
05:33:21     INFO -      rbx = 0x00007f28a49032e0   r12 = 0x00007f289ca10f90
05:33:21     INFO -      r13 = 0x0000000000074f9c   r14 = 0x0000000000000000
05:33:21     INFO -      r15 = 0x00007f27bd7ff000   rip = 0x00007f28f46fe837
05:33:21     INFO -      rsp = 0x00007ffff2a372f0   rbp = 0x00007ffff2a37310
05:33:21     INFO -      Found by: given as instruction pointer in context
05:33:21     INFO -   1  libxul.so!mozilla::WebGLObserver::Destroy() [WebGLContext.cpp:5a8e5ad43d90 : 87 + 0x4]
05:33:21     INFO -      rbx = 0x00007f28a49032e0   r12 = 0x00007f289ca10f90
05:33:21     INFO -      r13 = 0x0000000000074f9c   r14 = 0x0000000000000000
05:33:21     INFO -      r15 = 0x00007f27bd7ff000   rip = 0x00007f28f46ff860
05:33:21     INFO -      rsp = 0x00007ffff2a37320   rbp = 0x00007ffff2a37330
05:33:21     INFO -      Found by: call frame info
05:33:21     INFO -   2  libxul.so!mozilla::WebGLContext::~WebGLContext() [WebGLContext.cpp:5a8e5ad43d90 : 318 + 0x13]
05:33:21     INFO -      rbx = 0x00007f289ca10c00   r12 = 0x00007f289ca10f90
05:33:21     INFO -      r13 = 0x0000000000074f9c   r14 = 0x0000000000000000
05:33:21     INFO -      r15 = 0x00007f27bd7ff000   rip = 0x00007f28f47082bc
05:33:21     INFO -      rsp = 0x00007ffff2a37340   rbp = 0x00007ffff2a37350
05:33:21     INFO -      Found by: call frame info
05:33:21     INFO -   3  libxul.so!mozilla::WebGL1Context::~WebGL1Context() [WebGL1Context.cpp:5a8e5ad43d90 : 25 + 0x4]
05:33:21     INFO -      rbx = 0x00007f289ca10c00   r12 = 0x00007ffff2a373d8
05:33:21     INFO -      r13 = 0x0000000000074f9c   r14 = 0x0000000000000000
05:33:21     INFO -      r15 = 0x00007f27bd7ff000   rip = 0x00007f28f47085da
05:33:21     INFO -      rsp = 0x00007ffff2a37360   rbp = 0x00007ffff2a37370
05:33:21     INFO -      Found by: call frame info
05:33:21     INFO -   4  libxul.so!SnowWhiteKiller::~SnowWhiteKiller() [nsCycleCollector.cpp:5a8e5ad43d90 : 2611 + 0xc]
05:33:21     INFO -      rbx = 0x00007f28deff76a8   r12 = 0x00007ffff2a373d8
05:33:21     INFO -      r13 = 0x0000000000074f9c   r14 = 0x0000000000000000
05:33:21     INFO -      r15 = 0x00007f27bd7ff000   rip = 0x00007f28f36e3a36
05:33:21     INFO -      rsp = 0x00007ffff2a37380   rbp = 0x00007ffff2a373a0
05:33:21     INFO -      Found by: call frame info


Note how the last stack frame above shows that it's the cycle collector that is reaping the WebGLContext.

Comment 1

[Benoit Jacob [:bjacob] (mostly away)]

Actually, it seems pretty perma-orange at the moment...

Comment 2

[Benoit Jacob [:bjacob] (mostly away)]

Attachment: fix-webgl

Comment 3

[Olli Pettay [:smaug][[e-mail]]]

Comment on attachment 8445136 [details] [diff] [review]
fix-webgl

s/Do not assert on observerService here.//

Comment 4

[Benoit Jacob [:bjacob] (mostly away)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/de2f8eca84b1

(Sorry, did not see your comment suggestion in time. Hope it's OK. I think that that comment is actually useful to prevent people from re-adding it, as a nearby function in this file still has a similar assertion.)

Comment 5

[Olli Pettay [:smaug][[e-mail]]]

Well, I'd just prefer us to not add useless assertion, and not even comments about such.

Either you add an assertion or you add 'if', but not both.

Comment 6

[Benoit Jacob [:bjacob] (mostly away)]

That's true. Let's needinfo the WebGL guys to make sure they see this :-)

Comment 7

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/de2f8eca84b1

Comment 8

[Kelsey Gilbert [:jgilbert]]

(In reply to Olli Pettay [:smaug] from comment #5)
> Well, I'd just prefer us to not add useless assertion, and not even comments
> about such.
> 
> Either you add an assertion or you add 'if', but not both.

Well, this is an unfortunate truth that is only true because we don't have a more sophisticated method than crash reports to report these failures.

Comment 9

[Jerry Shih[:jerry] (UTC+8) (inactive)]

Comment on attachment 8445136 [details] [diff] [review]
fix-webgl

[Approval Request Comment]
Bug caused by (feature/regressing bug #):
bug 998916
User impact if declined:
We will get some intermittently failed on test for 2.0. We already have this fix for master.
Testing completed:
https://treeherder.mozilla.org/ui/#/jobs?repo=try&revision=329989e86b83
Risk to taking this patch (and alternatives if risky):
low
String or UUID changes made by this patch:
none

Comment 10

[Jerry Shih[:jerry] (UTC+8) (inactive)]

Could you please check the comment 9?
We need this patch for bug 998916.
https://bugzilla.mozilla.org/show_bug.cgi?id=998916#c79

Comment 11

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-b2g32_v2_0/rev/109bf3dc61cf

Comment 12

[Kai-Zhen Li [:seinlin][:kli]]

https://hg.mozilla.org/releases/mozilla-b2g32_v2_0m/rev/109bf3dc61cf