1448194 - Intermittent GECKO(1433) | Assertion failure: CanDecodeOffThread(cx, options, range.length()), at /builds/worker/workspace/build/src/js/src/jsapi.cpp:4343

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect, P5)

Description

[Treeherder Bug Filer]

Filed by: ebalazs [at] mozilla.com

https://treeherder.mozilla.org/logviewer.html#?job_id=169759177&repo=mozilla-inbound

https://queue.taskcluster.net/v1/task/eErI00fFQHyWVw0SZUG8Qw/runs/0/artifacts/public/logs/live_backing.log

Comment 1

[Intermittent Failures Robot]

6 failures in 822 pushes (0.007 failures/push) were associated with this bug in the last 7 days.    

Repository breakdown:
* mozilla-inbound: 3
* mozilla-central: 2
* try: 1

Platform breakdown:
* windows7-32: 2
* windows10-64: 2
* linux64-qr: 2

For more details, see:
https://treeherder.mozilla.org/intermittent-failures.html#/bugdetails?bug=1448194&startday=2018-03-20&endday=2018-03-26&tree=trunk

Comment 2

[Intermittent Failures Robot]

2 failures in 718 pushes (0.003 failures/push) were associated with this bug in the last 7 days.    

Repository breakdown:
* try: 1
* autoland: 1

Platform breakdown:
* windows10-64: 1
* linux64-qr: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures.html#/bugdetails?bug=1448194&startday=2018-03-26&endday=2018-04-01&tree=trunk

Comment 3

[André Bargull [:anba]]

ScriptLoader::AttemptAsyncScriptCompile() checks JS::CanDecodeOffThread() [1] before calling JS::DecodeOffThreadScript() [2], but at [1] the value of |ScriptLoadRequest::mBytecodeOffset| is ignored, whereas the failing assertion includes |mBytecodeOffset| when calling JS::CanDecodeOffThread() [3].

@nbp: Does that sound like plausible explanation for this assertion error?


[1] https://searchfox.org/mozilla-central/rev/b80994a43e5d92c2f79160ece176127eed85dcc9/dom/script/ScriptLoader.cpp#1803
[2] https://searchfox.org/mozilla-central/rev/b80994a43e5d92c2f79160ece176127eed85dcc9/dom/script/ScriptLoader.cpp#1830-1834
[3] https://searchfox.org/mozilla-central/rev/b80994a43e5d92c2f79160ece176127eed85dcc9/js/src/jsapi.cpp#4334-4335

Comment 4

[Nicolas B. Pierron [:nbp]]

(In reply to André Bargull [:anba] from comment #3)
> ScriptLoader::AttemptAsyncScriptCompile() checks JS::CanDecodeOffThread()
> [1] before calling JS::DecodeOffThreadScript() [2], but at [1] the value of
> |ScriptLoadRequest::mBytecodeOffset| is ignored, whereas the failing
> assertion includes |mBytecodeOffset| when calling JS::CanDecodeOffThread()
> [3].
> 
> @nbp: Does that sound like plausible explanation for this assertion error?

Yes, Good catch!

mBytecodeOffset is set to the size of the SRI data, which is only a few bytes compared to the 367 kB expected.

You can potentially reproduce this precise error by changing one of the JS files loaded by dom/base/test/test_script_loader_js_cache.html test case, and appending characters to a dummy comment at the end of one of the file.

Comment 5

[Nicolas B. Pierron [:nbp]]

Attachment: Substract the mBytecodeOffset from the bytecode length, as this could cause some assertion failures.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/be6e3454d8dd
Substract the mBytecodeOffset from the bytecode length, as this could cause some assertion failures. r=mrbkap

Comment 7

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/be6e3454d8dd

Comment 8

[Intermittent Failures Robot]

3 failures in 765 pushes (0.004 failures/push) were associated with this bug in the last 7 days.    

Repository breakdown:
* mozilla-inbound: 1
* mozilla-central: 1
* autoland: 1

Platform breakdown:
* windows7-32: 1
* osx-10-10: 1
* linux64: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures.html#/bugdetails?bug=1448194&startday=2018-04-02&endday=2018-04-08&tree=trunk