439488 - Firefox uses 100% cpu load when opening menu while download is running

Status: RESOLVED INCOMPLETE

(Core :: Widget: Cocoa, defect, P1)

Description

[Henrik Skupin [:whimboo][⌚️UTC+2]]

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.4; en-US; rv:1.9pre) Gecko/2008060804 Minefield/3.0pre ID:2008060804

Opening a menu entry from the main menu while a download is running causes Firefox to use 100% cpu load.

Steps to reproduce:
1. Create a fresh profile and start Firefox
2. Open the following URL and save it to the local disk
3. While the download is running open the "Tools" menu and let stay it open

As you can see Firefox uses more and more cpu load until 100% is reached after some seconds. Whether the menu is opened or not, Firefox should stay at a normal cpu load.

I don't have an idea which is the best product/component to place this bug. So please re-adjust if it's not correct. Thanks.

Comment 1

[Henrik Skupin [:whimboo][⌚️UTC+2]]

This issue seems to be OS X only. I cannot reproduce on Windows XP.

Comment 2

[Steven Michaud [:smichaud] (Retired)]

I see this too, though my results aren't as dramatic as Henrik's
(possibly because I tested on a fast machine -- a recent MacPro).

While a native menu (i.e. the main menu) is open (in FF3), I see the
CPU percentage (in top) gradually creep upward.  I don't see this with
non-native menus (e.g. context menus or Places menus).  The same
pattern holds in trunk (aka 1.9-branch) Camino (which has native
context menus), where I see the problem both with the main menu and
with context menus.

I don't see this problem in FF2 or 1.8-branch Camino (e.g. Camino
1.6).

I don't see it in Safari.

I don't see it (in FF3) on Linux.

All this suggests this is an Apple bug (even though Safari isn't
effected).  But since the bug (probably) doesn't effect any of Apple's
"own" products, we'll (probably) have to find a workaround.  And that
workaround will (if I can find one) be added to Cocoa widgets code.

I'm marking this P2, because I suspect it won't often be encountered.

It'd be nice to have a regression range for this.  Henrik? :-)

Comment 3

[Steven Michaud [:smichaud] (Retired)]

I should add that I tested on OS X 10.5.3.

Comment 4

[Henrik Skupin [:whimboo][⌚️UTC+2]]

I'll try to find the regression range within the next days.

Comment 5

[Steven Michaud [:smichaud] (Retired)]

One more thing (at least in my tests):

The problem goes away when you close the native menu (CPU percentage
goes back to what it was before you opened the native menu).  Then
when you open another native menu (or reopen the same one), the CPU
percentage doesn't immediately go back to what it was just before you
closed the last native menu.  Instead the CPU percentage gradually
builds up again "from the beginning".

Comment 6

[Henrik Skupin [:whimboo][⌚️UTC+2]]

I did a test run on OS X 10.5.2 and I'm not able to see this bug. The cpu load is still at around 17%. I'll install the latest OS X update for Leopard. Perhaps one of the contained updates could have regressed that one? Lets see.

Comment 7

[Henrik Skupin [:whimboo][⌚️UTC+2]]

Even with 10.5.3 it's not reproducible. I can only see some small spikes up to 90% but it goes quickly back to 15%. Looks like that this bug only happens on 10.4. Anyone who can also reproduce it on 10.4? If yes, I would like to start finding the regression range.

Comment 8

[Steven Michaud [:smichaud] (Retired)]

> Looks like that this bug only happens on 10.4

Nope.  I saw it (or some variant of it) on 10.5.3.

Comment 9

[Henrik Skupin [:whimboo][⌚️UTC+2]]

(In reply to comment #8)
> > Looks like that this bug only happens on 10.4
> 
> Nope.  I saw it (or some variant of it) on 10.5.3.

You could also have seen bug 397424. Perhaps you could try to figure it out?

Comment 10

[Steven Michaud [:smichaud] (Retired)]

This was never reproducible enough to make it worth trying to fix.