1501748 - ANR executing service org.mozilla.firefox/org.mozilla.gecko.GeckoService

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: General, defect, P2)

Description

[Marcia Knous [:marcia]]

Seen while looking at Google Play information - executing service org.mozilla.firefox/org.mozilla.gecko.GeckoService comes up as affecting users. It seems in the past we had a similar bug in the 51 cycle, Bug 1347875 which was eventually resolved invalid.

Similar to Bug 1501449, the affected devices seem to be all Samsung, but not all are running Android 8.0.

Comment 1

[Pascal Chevrel:pascalc (PTO until April 26)]

Susheel, can we get this bug prioritized and assigned? Thanks

Comment 2

[:sdaswani]

Sure, using the new prioritization per :lizzard. Marcia let me know if you think this should be more than a P2.

Comment 3

[Liz Henry (:lizzard) (relman/hg->git project)]

Sylvestre, this is hard for the team to investigate if they can't see the Play STore reports.  Can we give access at some level for Petru Lingurar, Vlad Baicu, and Andrei Lazar? Thanks!

Comment 4

[Sylvestre Ledru [:Sylvestre]]

Done! Next time, please open a separate bug for this as this isn't related to the ANR issue.

Comment 5

[Petru-Mugurel Lingurar [:petru]]

Interestingly, all such ANRs started to appear October 2nd and just in 62.0.3
So I think it is a regression introduced by one of this patches https://hg.mozilla.org/releases/mozilla-release/pushloghtml?fromchange=FIREFOX_62_0_2_RELEASE&tochange=FIREFOX_62_0_3_RELEASE

Comment 6

[Petru-Mugurel Lingurar [:petru]]

When GeckoService() is destroyed we block it's onDestroy() until Gecko handles OnPause() [1]
The issue is that the standard ANR timeout expires before that happens.
In GPC I see that main is not blocked but it waits for that Gecko call to finish.
And then I see that the timeout expired on GeckoLoader.nativeRun()
> "Gecko" prio=5 tid=13 Native
>        | group="main" sCount=1 dsCount=0 flags=1 obj=0x134008a8 self=0xdbdb1e00
>        | sysTid=5993 nice=0 cgrp=default sched=0/0 handle=0xc8b48970
>        | state=S schedstat=( 6406333549 1738291105 9010 ) utm=562 stm=78 core=1 HZ=100
>        | stack=0xc8a46000-0xc8a48000 stackSize=1038KB
>        | held mutexes=
>  #00  pc 0000000000018eac  /system/lib/libc.so (syscall+28)
>  #01  pc 000000000004846d  /system/lib/libc.so (_ZL24__pthread_cond_timedwaitP23pthread_cond_internal_tP15pthread_mutex_tbPK8timespec+102)
>  #02  pc 0000000000052b53  /data/app/org.mozilla.firefox-8GK6Ju2ILM1wm2ZiMN9TjQ==/lib/arm/libmozglue.so (???)
>        at org.mozilla.gecko.mozglue.GeckoLoader.nativeRun (Native method)
>        at org.mozilla.gecko.GeckoThread.run (GeckoThread.java:498)

[1] https://dxr.mozilla.org/mozilla-central/rev/b3da3f53f8042d6e2e8f90cd0086e354d96ba2fc/mobile/android/base/java/org/mozilla/gecko/GeckoService.java#106

Comment 7

[Petru-Mugurel Lingurar [:petru]]

There's a massive drop in this ANR's occurrences after October 8th, the date 63 was pushed to all users.
This ANR does not show on latest release, all it's occurrences being still tied to the 62.0.3 release.

I think this may have been resolved with the latest release but will keep the ticket open to continue tracking it.

Comment 8

[Liz Henry (:lizzard) (relman/hg->git project)]

Petru will follow up and make sure this is no longer showing up in 63.

Comment 9

[Pascal Chevrel:pascalc (PTO until April 26)]

Wontfix for 63 because of comment #7 + we are unlikely to have another dot release before 64 ships in 3 weeks from now.

Comment 10

[Petru-Mugurel Lingurar [:petru]]

That ANR signature doesn't appear for 63 anymore as the code was refactored so the ANR migrated to:
> executing service org.mozilla.firefox/org.mozilla.gecko.GeckoServicesCreatorService
same underlying source,
>  #01  pc 0000000000047b37  /system/lib/libc.so >(_ZL24__pthread_cond_timedwaitP23pthread_cond_internal_tP15pthread_mutex_tbPK8timespec+102)
> 
> #02  pc 000000000005138b  /data/app/org.mozilla.firefox-Z4u94PeFNgRgfv6QoB49Ew==/lib/arm/libmozglue.so (???)
> 
>  at org.mozilla.gecko.GeckoThread.waitOnGecko (Native method)
> 
>  at org.mozilla.gecko.GeckoService.onDestroy (GeckoService.java:106)

As I understand, that GeckoThread.waitOnGecko() just adds a new event to be processed after the previous call on GeckoThread finishes, effectively blocking the current thread - Main, until previous event - GeckoThread.onPause()[1] is handled.

James, can someone from Gecko take a look at why GeckoThread.onPause() takes so long to complete?

[1] https://dxr.mozilla.org/mozilla-central/source/mobile/android/base/java/org/mozilla/gecko/GeckoService.java#101

Comment 11

[James Willcox (:snorp) ([e-mail]) (he/him)]

The Gecko thread is blocking on the UI thread for some reason. We have a few spots where we have to do this, and therefore it's not good to block the UI thread on Gecko. We should try to remove the waitForGecko() calls if able. Maybe we could add a timeout to waitForGecko()?

Comment 12

[Petru-Mugurel Lingurar [:petru]]

That waitOnGecko() was introduced by bug 1260243
> ... so that Gecko is more likely to be in a consistent state if Android kills our process
so I think removing it is not ideal.

Tried to add a timeout (cannot block for more than 5 seconds [1]) on just Java side but a proper solution would involve modifying the native method which I currently don't know how to.

Unassigning and NIing James to find a more suitable owner.

[1] https://developer.android.com/training/articles/perf-anr

Comment 13

[James Willcox (:snorp) ([e-mail]) (he/him)]

I'm working on a patch here.

Comment 14

[James Willcox (:snorp) ([e-mail]) (he/him)]

Attachment: Bug 1501748 - Make GeckoThread.waitOnGecko() time out by default.

All of the current usage can survive a timeout, and we'd rather
that than a deadlock. Future code that does want to risk a
deadlock can call `GeckoThread.waitOnGeckoForever` instead.

Comment 15

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9bca860f26dc
Make GeckoThread.waitOnGecko() time out by default. r=geckoview-reviewers,esawin

Comment 16

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/9bca860f26dc

Comment 17

[Ryan VanderMeulen [:RyanVM]]

Maybe worth considering for a Beta uplift after it's had some Nightly bake time.

Comment 18

[Liz Henry (:lizzard) (relman/hg->git project)]

Want to request uplift to beta?

Comment 19

[James Willcox (:snorp) ([e-mail]) (he/him)]

According to the play store this isn't fixed.

Comment 20

[James Willcox (:snorp) ([e-mail]) (he/him)]

All of the stacks I've seen on the play store have the Gecko thread waiting in VsyncSource.java:51. We can probably just make that part async.

Comment 21

[James Willcox (:snorp) ([e-mail]) (he/him)]

Attachment: Bug 1501748 - Avoid synchronous wait when creating VsyncSource r?#geckoview-reviewers

Comment 22

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d3b95f808e28
Avoid synchronous wait when creating VsyncSource r=geckoview-reviewers,droeh#geckoview-reviewers

Comment 23

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/d3b95f808e28

Comment 24

[Ritu Kothari (:ritu) (Inactive, please n-i to RyanVM, jcristau, or pascal)]

Hi James, could you please nominate this patch for uplift to Beta65 given https://bugzilla.mozilla.org/show_bug.cgi?id=1518285#c2? Thanks!

Comment 25

[James Willcox (:snorp) ([e-mail]) (he/him)]

Comment on attachment 9034470 [details]
Bug 1501748 - Avoid synchronous wait when creating VsyncSource r?#geckoview-reviewers

[Beta/Release Uplift Approval Request]

Feature/Bug causing the regression: Bug 1432019

User impact if declined: Occassional hangs in Fennec/GeckoView

Is this code covered by automated tests?: Yes

Has the fix been verified in Nightly?: No

Needs manual test from QE?: No

If yes, steps to reproduce: We don't have reliable STR.

List of other uplifts needed: None

Risk to taking this patch: Medium

Why is the change risky/not risky? (and alternatives if risky): Well-understood path, but does involve some thread interaction issues.

String changes made/needed: None

Comment 26

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9034470 [details]
Bug 1501748 - Avoid synchronous wait when creating VsyncSource r?#geckoview-reviewers

[Triage Comment]
The Fennec 65 ANR rate is super high at the moment. I'm going to uplift this and respin 65.0b9 so we can get some quick feedback on impact. We can also spin a b10 later this week if this patch proves insufficient.

Comment 27

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/f7c20de04f4d

Comment 28

[Mike de Boer [:mikedeboer]]

https://hg.mozilla.org/projects/cedar/rev/d3b95f808e2878849127b8f4fc43527202eecf2a
Bug 1501748 - Avoid synchronous wait when creating VsyncSource r=geckoview-reviewers,droeh#geckoview-reviewers