1357219 - 4,400 instances of "'NS_FAILED(rv)'" emitted from dom/xhr/XMLHttpRequestMainThread.cpp during linux64 debug testing

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect, P2)

Description

[Eric Rahm [:erahm]]

> 4414 WARNING: 'NS_FAILED(rv)', file dom/xhr/XMLHttpRequestMainThread.cpp, line 2000

This warning [1] shows up in the following test suites:

>    443 - test-linux64/debug-mochitest-browser-chrome-9 bc9
>    414 - test-linux64/debug-mochitest-browser-chrome-e10s-5 bc5
>    306 - test-linux64/debug-mochitest-browser-chrome-e10s-15 bc15
>    276 - test-linux64/debug-mochitest-browser-chrome-e10s-6 bc6
>    267 - test-linux64/debug-mochitest-browser-chrome-16 bc16
>    240 - test-linux64/debug-mochitest-browser-chrome-2 bc2
>    195 - test-linux64/debug-mochitest-browser-chrome-1 bc1
>    183 - test-linux64/debug-mochitest-browser-chrome-e10s-4 bc4
>    175 - test-linux64/debug-mochitest-browser-chrome-e10s-16 bc16
>    118 - test-linux64/debug-mochitest-browser-chrome-14 bc14
>    115 - test-linux64/debug-mochitest-browser-chrome-15 bc15
>    109 - test-linux64/debug-mochitest-browser-chrome-e10s-13 bc13
>     95 - test-linux64/debug-mochitest-browser-chrome-e10s-14 bc14
>     74 - test-linux64/debug-mochitest-browser-chrome-e10s-10 bc10
>     66 - test-linux64/debug-mochitest-browser-chrome-e10s-8 bc8
>     56 - test-linux64/debug-mochitest-browser-chrome-10 bc10
>     54 - test-linux64/debug-mochitest-clipboard-e10s cl
>     54 - test-linux64/debug-mochitest-clipboard cl
>     54 - test-linux64/debug-mochitest-browser-chrome-11 bc11
>     54 - test-linux64/debug-mochitest-browser-chrome-e10s-1 bc1
>     51 - test-linux64/debug-mochitest-browser-chrome-8 bc8
>     44 - test-linux64/debug-mochitest-browser-chrome-e10s-9 bc9
>     40 - test-linux64/debug-firefox-ui-functional-remote en-US
>     40 - test-linux64/debug-firefox-ui-functional-remote-e10s en-US
>     40 - test-linux64/debug-mochitest-browser-chrome-6 bc6
>     39 - test-linux64/debug-mochitest-browser-chrome-7 bc7
>     39 - test-linux64/debug-mochitest-browser-chrome-e10s-7 bc7
>     36 - test-linux64/debug-mochitest-browser-chrome-e10s-2 bc2
>     34 - test-linux64/debug-mochitest-browser-chrome-3 bc3
>     33 - test-linux64/debug-mochitest-browser-chrome-e10s-3 bc3
>     27 - test-linux64/debug-mochitest-devtools-chrome-e10s-5 dt5
>     27 - test-linux64/debug-mochitest-jetpack JP
>     24 - test-linux64/debug-mochitest-e10s-1 1
>     24 - test-linux64/debug-mochitest-browser-chrome-4 bc4
>     24 - test-linux64/debug-mochitest-1 1
>     24 - test-linux64/debug-mochitest-browser-chrome-5 bc5
>     21 - test-linux64/debug-mochitest-devtools-chrome-e10s-4 dt4
>     21 - test-linux64/debug-mochitest-10 10
>     21 - test-linux64/debug-mochitest-e10s-10 10
>     18 - test-linux64/debug-mochitest-devtools-chrome-1 dt1
>     18 - test-linux64/debug-mochitest-devtools-chrome-3 dt3
>     18 - test-linux64/debug-mochitest-devtools-chrome-e10s-1 dt1
>     18 - test-linux64/debug-mochitest-devtools-chrome-e10s-6 dt6
>     16 - test-linux64/debug-mochitest-chrome-1 c1
>     15 - test-linux64/debug-mochitest-e10s-6 6
>     15 - test-linux64/debug-mochitest-devtools-chrome-6 dt6
>     15 - test-linux64/debug-mochitest-e10s-7 7
>     15 - test-linux64/debug-mochitest-7 7
>     15 - test-linux64/debug-mochitest-devtools-chrome-8 dt8
>     15 - test-linux64/debug-mochitest-6 6
>     15 - test-linux64/debug-mochitest-a11y a11y
>     12 - test-linux64/debug-mochitest-e10s-9 9
>     12 - test-linux64/debug-mochitest-chrome-3 c3
>     12 - test-linux64/debug-mochitest-e10s-2 2
>     12 - test-linux64/debug-mochitest-devtools-chrome-4 dt4
>     12 - test-linux64/debug-mochitest-2 2
>     12 - test-linux64/debug-mochitest-devtools-chrome-e10s-2 dt2
>     12 - test-linux64/debug-mochitest-devtools-chrome-5 dt5
>     12 - test-linux64/debug-mochitest-devtools-chrome-e10s-3 dt3
>     12 - test-linux64/debug-mochitest-devtools-chrome-7 dt7
>     12 - test-linux64/debug-mochitest-5 5
>     12 - test-linux64/debug-mochitest-devtools-chrome-2 dt2
>     12 - test-linux64/debug-mochitest-8 8
>     12 - test-linux64/debug-firefox-ui-functional-local en-US
>      9 - test-linux64/debug-mochitest-e10s-8 8
>      9 - test-linux64/debug-mochitest-3 3
>      9 - test-linux64/debug-mochitest-e10s-3 3
>      9 - test-linux64/debug-mochitest-9 9
>      9 - test-linux64/debug-mochitest-e10s-5 5
>      6 - test-linux64/debug-mochitest-devtools-chrome-9 dt9
>      6 - test-linux64/debug-mochitest-devtools-chrome-e10s-9 dt9
>      6 - test-linux64/debug-mochitest-devtools-chrome-e10s-8 dt8
>      6 - test-linux64/debug-mochitest-devtools-chrome-e10s-7 dt7
>      6 - test-linux64/debug-mochitest-chrome-2 c2
>      3 - test-linux64/debug-mochitest-devtools-chrome-10 dt10
>      3 - test-linux64/debug-mochitest-e10s-4 4
>      3 - test-linux64/debug-mochitest-devtools-chrome-e10s-10 dt10
>      3 - test-linux64/debug-mochitest-media-3 mda3
>      3 - test-linux64/debug-mochitest-browser-chrome-e10s-12 bc12
>      3 - test-linux64/debug-mochitest-browser-chrome-13 bc13
>      3 - test-linux64/debug-mochitest-media-e10s-3 mda3
>      3 - test-linux64/debug-mochitest-4 4
>      3 - test-linux64/debug-mochitest-browser-chrome-e10s-11 bc11
>      3 - test-linux64/debug-mochitest-browser-chrome-12 bc12
>      3 - test-linux64/debug-mochitest-gpu-e10s gpu

It shows up in 857 tests. A few of the most prevalent:

>    107 -        browser/components/search/test/browser_yahoo_behavior.js
>     84 - [e10s] browser/base/content/test/general/browser_aboutHome.js
>     84 -        browser/base/content/test/general/browser_aboutHome.js
>     59 -        browser/components/search/test/browser_amazon_behavior.js
>     54 - [e10s] browser/modules/test/browser/browser_ContentSearch.js
>     51 -        browser/modules/test/browser/browser_ContentSearch.js
>     47 - [e10s] browser/components/search/test/browser_amazon_behavior.js
>     46 - [e10s] browser/modules/test/browser/browser_UsageTelemetry_urlbar.js
>     46 - [e10s] browser/components/search/test/browser_webapi.js
>     46 -        browser/modules/test/browser/browser_UsageTelemetry_urlbar.js

[1] https://hg.mozilla.org/mozilla-central/annotate/cac374fb0de1/dom/xhr/XMLHttpRequestMainThread.cpp#l2000

Comment 1

[Eric Rahm [:erahm]]

Mike, bisection points to a large uptick in this warning with the landing of bug 1337560.

Comment 2

[Mike Kaply [:mkaply]]

Is it showing up on any other platforms? Or is this unique to Linux?

Comment 3

[Eric Rahm [:erahm]]

(In reply to Mike Kaply [:mkaply] from comment #2)
> Is it showing up on any other platforms? Or is this unique to Linux?

I'll take a look. Also it looks like it's more prevalent than I thought: 9,100 instances of "'NS_FAILED(rv)'" emitted.

Comment 4

[Eric Rahm [:erahm]]

Looks like it's all platforms, more prevalent on windows and linux, but we don't run as many tests on OSX so that's expected.

9,500 instances of "'NS_FAILED(rv)'" emitted from dom/xhr/XMLHttpRequestMainThread.cpp during windows7-32-vm debug testing

> 9496 WARNING: 'NS_FAILED(rv)', file dom/xhr/XMLHttpRequestMainThread.cpp, line 2000

4,900 instances of "'NS_FAILED(rv)'" emitted from dom/xhr/XMLHttpRequestMainThread.cpp during osx-10-10 debug testing

> 4942 WARNING: 'NS_FAILED(rv)', file dom/xhr/XMLHttpRequestMainThread.cpp, line 2000

Comment 5

[Mike Kaply [:mkaply]]

Ok that's helpful. I'll try to recreate and fix.

Comment 6

[Mike Kaply [:mkaply]]

OK, I have some output, but the error makes no sense.

On this line

https://hg.mozilla.org/mozilla-central/annotate/cac374fb0de1/dom/xhr/XMLHttpRequestMainThread.cpp#l1999

file is

chrome/en-US/locale/browser/searchplugins/images/wikipedia.ico or
chrome/en-US/locale/browser/searchplugins/images/amazon.ico or
chrome/en-US/locale/browser/searchplugins/images/wikipedia.ico

jarFile is

/home/worker/workspace/build/application/firefox/browser/omni.ja

I've unzipped the omni.ja file in browser and it has 

./chrome/en-US/locale/browser/searchplugins/images/amazon.ico
./chrome/en-US/locale/browser/searchplugins/images/wikipedia.ico
./chrome/en-US/locale/browser/searchplugins/images/yahoo.ico

Next up is getting more information about where mapToFileInPackage is failing.

Comment 7

[Mike Kaply [:mkaply]]

OK, so the problem is that the function mapToFileInPackage doesn't support compressed files.

https://hg.mozilla.org/mozilla-central/annotate/cac374fb0de1/dom/xhr/XMLHttpRequestMainThread.cpp#l3994

It returns failure in that case. 

But everything still works. So I don't think this function should be doing an NS_WARN in this case.

I've emailed the person who wrote this code, but I have not gotten a response yet.

At this point, I recommend removing the NS_WARN.

Comment 8

[Eric Rahm [:erahm]]

(In reply to Mike Kaply [:mkaply] from comment #7)
> OK, so the problem is that the function mapToFileInPackage doesn't support
> compressed files.
> 
> https://hg.mozilla.org/mozilla-central/annotate/cac374fb0de1/dom/xhr/
> XMLHttpRequestMainThread.cpp#l3994
> 
> It returns failure in that case. 
> 
> But everything still works. So I don't think this function should be doing
> an NS_WARN in this case.
> 
> I've emailed the person who wrote this code, but I have not gotten a
> response yet.
> 
> At this point, I recommend removing the NS_WARN.

Thanks for looking into this Mike, that seems reasonable or perhaps we can bail earlier?

Comment 9

[Mike Kaply [:mkaply]]

Attachment: Bug 1357219 - Don't warn if we can't use a memory mapped file.

Review commit: https://reviewboard.mozilla.org/r/132532/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/132532/

Comment 10

[Mike Kaply [:mkaply]]

> Thanks for looking into this Mike, that seems reasonable or perhaps we can bail earlier?

Unfortunately we can't bail earlier because we need to have opened the zip to realize the problem.

Comment 11

[Jed Davis [:jld] ⟨⏰|UTC-7⟩ ⟦he/him⟧]

The backstory here is bug 945152; this was a useful memory-saving feature on B2G, and I'm assuming the warning was meant to detect regressions or other cases where direct memory-mapping was expected but didn't happen.  I don't know whether we're actively using it for anything on desktop.  But the fact that the XHR is set to yield an ArrayBuffer isn't sufficient to indicate that intent (as we can see here), so it does seem reasonable to turn off the warning.

Comment 12

[Jed Davis [:jld] ⟨⏰|UTC-7⟩ ⟦he/him⟧]

Comment on attachment 8860525 [details]
Bug 1357219 - Don't warn if we can't use a memory mapped file.

https://reviewboard.mozilla.org/r/132532/#review135414

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2c9b48cce0db
Don't warn if we can't use a memory mapped file. r=jld

Comment 14

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/2c9b48cce0db