Comment 8 for bug 20765

Hi,

I get this ALL the time. It is not (just) a gecko problem or a DNS resolver
thread problem.

How to reproduce: open a number of tabs (preferably complex sites, eg. yahoo or
slashdot)

Reproducable: always

Result: Cursor changes to hourglass. Complete Firefox application freezes for a
few seconds, other tasks are not affected.

Expected Result: Tab may load/freeze but rest of Firefox (e.g.: other tabs,
menu) should still respond.

- It is not the history file (cleared that, restarted, problem remains).

- It is not a local proxy problem (problem remains with and without squid and/or
privoxy or direct)

- It is not version dependant (can be reproduced with Mozilla 1.7x, Firefox
1.0-1.0.3, etc., seems to happen in Thunderbird as well not sure)

- It is not Hyperthreading relevant:
https://bugzilla.mozilla.org/show_bug.cgi?id=277547
I do not not have an HT intel chip.

Assumption: It seems to be that Gecko "hangs" a bit on pondering the layout
complex pages (e.g. Slashdot) before rendering starts. This may also happen
when rendering has started and sub-sections of the page need to be rendered.

My personal analysis: That Gecko hangs is not the real problem however. What
the user expects is that on opening a new window/tab is that Firefox starts a
new Thread for that window/tab and even if the "new" tab hangs he should still
be able to use his present tab or access the menu commands.

Sugested resolution: add a new thread for each tab/window. (Assuming my
analysis is correct).

Cheers,
  Duncan

PS: I think Bug #248345 is a dupe of this bug, 277547 may be as well but perhaps
there are HT issues I don't know about.