379248 - Recursion check seems to be slower with getElementsByName use

Status: RESOLVED WORKSFORME

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

Description

[Martijn Wargers (dead)]

Attachment: testcase

This came from Hendrix feedback:
http://groups.google.com/group/mozilla.feedback/browse_thread/thread/71383d0da773dd69/a749e0d4099647ce#a749e0d4099647ce

That page hangs for a while at the end of page load. It happens because of a (bogus) function that recursively calls itself (getMeta) (even multiple times).
But in Mozilla1.7, the "too much recursion" check seems to happen very much quicker than in current builds, so the hang doesn't happen nearly as long in older builds.

See the zipped testcase.
When clicking on the "getElementsByName recursive" button, the browser hangs for a little while before the error gets thrown.
When clicking on the "getElementsByTagName recursive" button, the browser seems to throw much quicker.
This regressed between 2005-10-03 and 2005-10-04:
http://bonsai.mozilla.org/cvsquery.cgi?treeid=default&module=all&branch=HEAD&branchtype=match&dir=&file=&filetype=match&who=&whotype=match&sortby=Date&hours=2&date=explicit&mindate=2005-10-03+04&maxdate=2005-10-04+09&cvsroot=%2Fcvsroot
It seems to me this is a regression from bug 310351, somehow.


Not really related to this bug:
I also added 2 buttons that test getElementsByName and getElementsByTagName performance.
Results in various builds:
2005-10-03
2656ms
718ms

2005-10-04
2937ms
656ms

2007-04-29
3531ms
875ms

2007-01-02
3188ms
890ms

2006-10-01
3312ms
922ms

Comment 1

[Blake Kaplan (:mrbkap) (inactive)]

Perhaps this is a result of bug 335058?

Comment 2

[(mostly gone) XtC4UaLL [:xtc4uall]]

Against Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/16.0 Firefox/16.0a1 ID:20120617030532 I get 11ms for the getElementsByName/getElementsByTagName Cases and "Error: too much recursion" Errors in Error Console for the other two Cases.

Comment 3

[Boris Zbarsky [:bzbarsky]]

Just retested with the testcase modified to log how long it takes to hit the infinite recursion exception, and now getElementsByName is identical to getElementsByTagName.