792508 - Hang when reflowing very deeply nested tables with percentage heights on all elements

Status: NEW

(Core :: Layout: Tables, defect)

Description

[Grzegorz Szeliga]

Attachment: testcase

User Agent: Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1

Steps to reproduce:

Open the page


Actual results:

Open the


Expected results:

Browser crash

Comment 1

[[:Aleksej]]

2012-09-18-03-05-53-mozilla-central-firefox-18.0a1.en-US.linux-x86_64 appears to hang.

killall -ILL:
bp-3a58a795-b969-4ca6-8fe6-4727f2120919 [@ nsHTMLReflowState::CalcLineHeight ]
bp-31c91fbf-821c-484c-ba7e-619bb2120919 [@ nsFloatManager::GetFlowArea ]
bp-09742a70-df91-49b6-a43b-aa7342120919 [@ nsTableFrame::GetTableFrame ]
bp-91d3b7b2-74d3-4aa2-86b8-c40bd2120919 [@ nsTableFrame::ReflowTable ]

I guess it’s “just” loading VERY slowly.

Comment 2

[Mats Palmgren (inactive)]

Loading the test in a debug build results in a bazillion:
WARNING: frame tree too deep; setting zero size and returning: file layout/generic/nsFrame.cpp, line 5317

I added some diagnostic counters in nsTableFrame::Reflow,
dumping out the results every 5 seconds (only counting table
frames here, "level 1" means topmost table).  Here's the
result between two consecutive samples:

level 1 tables did 1 reflows
level 2 tables did 1 reflows
level 3 tables did 2 reflows
level 4 tables did 2 reflows
level 5 tables did 2 reflows
level 6 tables did 2 reflows
level 7 tables did 2 reflows
level 8 tables did 2 reflows
level 9 tables did 2 reflows
level 10 tables did 2 reflows
level 11 tables did 2 reflows
level 12 tables did 2 reflows
level 13 tables did 2 reflows
level 14 tables did 2 reflows
level 15 tables did 2 reflows
level 16 tables did 2 reflows
level 17 tables did 2 reflows
level 18 tables did 3 reflows
level 19 tables did 4 reflows
level 20 tables did 6 reflows
level 21 tables did 11 reflows
level 22 tables did 20 reflows
level 23 tables did 38 reflows
level 24 tables did 75 reflows
level 25 tables did 148 reflows
level 26 tables did 295 reflows
level 27 tables did 589 reflows
level 28 tables did 1178 reflows
level 29 tables did 2355 reflows
level 30 tables did 4709 reflows
level 31 tables did 9418 reflows
level 32 tables did 18836 reflows
level 33 tables did 37671 reflows
level 34 tables did 75341 reflows

... same as above up to level 19 ...
level 20 tables did 7 reflows
level 21 tables did 12 reflows
level 22 tables did 22 reflows
level 23 tables did 43 reflows
level 24 tables did 84 reflows
level 25 tables did 166 reflows
level 26 tables did 332 reflows
level 27 tables did 664 reflows
level 28 tables did 1328 reflows
level 29 tables did 2655 reflows
level 30 tables did 5310 reflows
level 31 tables did 10618 reflows
level 32 tables did 21236 reflows
level 33 tables did 42472 reflows
level 34 tables did 84944 reflows

Comment 3

[Mats Palmgren (inactive)]

It seems the main cause for the reflow requests are RequestSpecialHeightReflow
due to most of the frames have a percentage height.  Bug 725437 looks similar.

Perhaps the first step would be to simply disable this for strict mode,
as bug 233306 suggests.