766792 - "ASSERTION: Somehow there's stuff in the op queue" in nsHtml5TreeOpExecutor::~nsHtml5TreeOpExecutor

Status: RESOLVED FIXED

(Core :: DOM: HTML Parser, defect)

Description

[Jesse Ruderman]

Attachment: testcase

With:

  user_pref("browser.tabs.loadDivertedInBackground", true);
  user_pref("dom.disable_open_during_load", false);
  user_pref("nglayout.debug.disable_xul_cache", true);
  user_pref("security.fileuri.strict_origin_policy", false);

The testcase triggers:

###!!! ASSERTION: Somehow there's stuff in the op queue.: 'mOpQueue.IsEmpty()', file parser/html/nsHtml5TreeOpExecutor.cpp, line 80

Related to bug 734015?

Comment 1

[Jesse Ruderman]

Attachment: stack trace

Comment 2

[Henri Sivonen (:hsivonen)]

(In reply to Jesse Ruderman from comment #0)
> Related to bug 734015?

Quite likely, actually. Either we could just delete the assertion, which could mask other bugs or we could explicitly clear the queue before the assertion if the executor has been backgrounded.

Comment 3

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

I can understand that bug 734015 ca make such assertion easier to fire, but how could it cause it?

Comment 4

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

I'll investigate this.

Comment 5

[Henri Sivonen (:hsivonen)]

My expectation is that what happens is this: previously, the parser thread probably scheduled to rambles on the main thread: first a runnable that caused a flush and then a runnable that caused the executor to be released. Now the flash gets deferred, so the queue won't be empty by the time the executor is released. This is harmless, if this only happens when the parser has been terminated anyway, which I expect to be the case.

Comment 6

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

Attachment: patch

Could we do this. Other option is to flush in nsHtml5ExecutorFlusher dtor
which ends up to
if (!mParser) {
  mOpQueue.Clear();
}

Comment 7

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

Attachment: patch

Comment 8

[Henri Sivonen (:hsivonen)]

Comment on attachment 635275 [details] [diff] [review]
patch

Thanks.

Comment 9

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

https://hg.mozilla.org/mozilla-central/rev/c83282305cb9