Bug 97424 – Hang in WebCore::SelectorDataList::execute<0>

• Component: CSS
• Status: RESOLVED CONFIGURATION CHANGED

[Mike Lawther]

As reported in http://code.google.com/p/chromium/issues/detail?id=148736:

We are seeing hangs in WebCore (83% of them hanging on http://live.gizmodo.com/).

Stack looks like:

0x5e612eee	 [chrome.dll]	 - selectorquery.cpp:118 (cs|src|ann)]	WebCore::SelectorDataList::execute<0>(WebCore::SelectorChecker const &,WebCore::Node *,WTF::Vector<WTF::RefPtr<WebCore::Node>,0> &)
0x5e612d50	 [chrome.dll]	 - selectorquery.cpp:62 (cs|src|ann)]	WebCore::SelectorDataList::queryAll(WebCore::SelectorChecker const &,WebCore::Node *)
0x5e612d0d	 [chrome.dll]	 - selectorquery.cpp:158 (cs|src|ann)]	WebCore::SelectorQuery::queryAll(WebCore::Node *)
0x5e611d1b	 [chrome.dll]	 - node.cpp:1624 (cs|src|ann)]	WebCore::Node::querySelectorAll(WTF::AtomicString const &,int &)

Looking at SelectorQuery.cpp:118, it looks like this:

117: while (n) {
118:   if (n->isElementNode())
119:     ...;

So it looks like the hang is due to an infinite loop over the tree.

Not sure how the tree gets in a state where such an infinite loop is possible, but filing the bug here anyway.

Antti - as you wrote the code initially, any ideas how this could be happening?

[Brent Fulgham]

This code has been significantly refactored since this patch was proposed. There doesn't seem to be any action we can take here.