Firefox / Mozilla goes into a livelock or hangs for a long time when browsing on the specified website



14 years ago
13 years ago


(Reporter: Felix Apitzsch, Unassigned)


Windows XP

Firefox Tracking Flags

(Not tracked)





14 years ago
User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8a2) Gecko/20040711 Firefox/0.9.0+
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8a2) Gecko/20040711 Firefox/0.9.0+

When browsing on the website the Browser (Mozilla 1.7.1,
FireFox 9.2 and Firefox-nightly-build-14-07-2004) sometimes needs a long time to
load a new page (from this website) or does not load the page at all. While
loading the browser freezes completely with 99% system-load.
Minimizing/restoring the browser window still works. The mouse cursor shows the
busy icon while over the webpage-area.
The error occurs only after browsing the site for a while and often changing the
website section. See reproducibility for details.

Reproducible: Sometimes
Steps to Reproduce:
This is not an exact click-to click description, but the error could be
reproduced this way in 90% of the test-runs I made.

1. Clear browser-cache and history (not sure if important)
2. Browse to
3. Klick on the start-cartoon to enter site
4. Now do some browsing:
4.1 View the latest 10 news-pages (arrow -> on the bottom)
4.2 click on some external news-links (not sure if important)
4.3 close new windows with external pages
5. Switch the "site-section":
5.1 There is picture of a desk in the upper-left part of the page. It display
different items (phone, postcards, magazines, ...). Each item represents a
"section" of the site. You can click on it to browse there. This is when the
error (sometimes) occurs.
5.2 Click on the postcards on the desk (url in status bar helps to identify the
right icon). 
5.3 Sometimes (not often) the browser already hangs at this point.
6. Browse some postcard (e.g. "cartoons"):
6.1 Click on the image of a postcard
6.2 You get a pop-up with the larger image of the postcard. Close it.
6.3 Repeat 6.2 with the next postcard. The more postcards you browse, the higher
the propability to reproduce the error later. Try 20+.
7. Switch the site-section (click on desk) to "aktuelle Ausgabe" ("actual" in url)
7.1 The error often occurs at this point.
7.2 click on one of the issues displayed.
8.0 Switch section to "Archiv"
8.1 The error should occur now
8.2 If browser still responding, switch section again by quickly clicking
"audio", "postcards", "Aktuell", "Kontakt", "Archiv"
9. If the error did not occur by now you faild to reproduce it.
9.1 Close browser and try again. Do more browsing between section-switching. 

Actual Results:  
Browser freezes, system load goes up to 100% (99% firefox.exe). About 80% of the
system load is kernel load.
Sometimes the browser recovers after about 20 seconds. Sometimes it does not for
over 2 minutes (I killed the process after that time).

Expected Results:  
Quickly loaded the new webpage.

Test machine is a pentium4, 2GHz, 1GB RAM, i850 chipset running windowsXPsp1.
Network connection is Gbit-Ethernet --> switch --> router/firewall
--DSL(786Kb/128Kb)--> ISP ( --> internet.
Connection to the webserver is good. Server reponds well.
Website layout is quite simple (I'm not a HTML expert).

I do not see a (no-error-) reason why the browser freezes.

Comment 1

14 years ago
I did some more testing and discovered, that there is a good chance, that the
browser recovers from hanging after some minutes (5min+). The duration of the
hanging varies from about 30 sec. to some minutes. It seems to depend on how
much browsing you did before (anywhere in the web - maybe special webpage
content). When the browser recovers and you "switch the section" again, there is
a really good chance, that the browser freezes again for some minutes. Other
links work fine.
The possibility, that the browser recovers means, the error is not a real
livelock, but a (too) large computation or an active polling for some event that
finaly happens.
I've experienced the same "lack in responsiveness" using Mozilla 1.7.3 on Linux
(as reported in bug #249262 and bug #249638), not on your webpage but while
browsing in general.

Thus I downgraded to Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6)
Gecko/20040113 and the problem is gone.

Please try Mozilla/Firefox with that Engine dated 20040113 and see if you still
get the livelocks on your web page.

Comment 3

14 years ago
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040113
shows the same behaviour (as reported in the bug-report).
It's a pity that it did not help you. But now I'm realizing, you are runnning
Windows and not Linux. I observe these "hangs" only on Version 1.7.x on Linux.

Thus it's probably a different bug.

Comment 5

14 years ago
WFM using Firefox 1.0 on Linux.

Felix, can you reproduce the problem using Firefox 1.0?

Comment 6

14 years ago
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041107
Firefox/1.0 still shows the behaviour described above.

I would like to extend my understanding of what is happening inside firefox
while in a (temporary) livelock and provide better debugging information. Is
there a way to create detailed logs (e.g. log function calls) with the regular
win32 build?
Product: Browser → Seamonkey
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Last Resolved: 13 years ago
Resolution: --- → EXPIRED
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