Bug 48549

Summary:

[Qt] refcount assertion on WebPageProxy, when closing a window

Product:

WebKit

Reporter:

zalan <zalan>

Component:

WebKit2

Assignee:

zalan <zalan>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

christian.webkit, commit-queue, darin, sam

Priority:

Keywords:

Version:

528+ (Nightly build)

Hardware:

OS:

Linux

Attachments:

Description	Flags
remove extra adoptref	sam: review-
retain WKPageRef	none

zalan

Reported 2010-10-28 12:19:09 PDT

ASSERTION FAILED: m_refCount > 0 (../../../qtwebkit-webkit2-dev/JavaScriptCore/wtf/RefCounted.h:83 bool WTF::RefCountedBase::derefBase()) occurs when closing a window. Apparently a ref is missing, when WebPageProxy is destroyed. I am still yet to check it out on Mac, but with Qt, it is easy to reproduce. It looks like, during the construction of a new page, we lose one ref in WebUIClient::createNewPage(), when we call adoptRef on the WebPageProxy object. I'm puzzled why this adoptRef is called (WebUIClient.cpp line#78), when we already call adoptRef on the object, when it is being created (WebPageProxy::create()). Looking at the 'new page' callback backtrace, I can't see where this extra (adopted) ref would come from. When adoptRef() is removed, refcount goes back to normal and no assert on window.close().

Attachments
remove extra adoptref (1.29 KB, patch) 2010-11-11 00:39 PST, zalan	sam: review-	Details Formatted Diff Diff
retain WKPageRef (1.22 KB, patch) 2010-11-19 06:12 PST, zalan	no flags	Details Formatted Diff Diff
View All Add attachment proposed patch, testcase, etc.

zalan

Comment 1 2010-11-11 00:39:03 PST

Created attachment 73586 [details] remove extra adoptref

Sam Weinig

Comment 2 2010-11-11 16:04:51 PST

Comment on attachment 73586 [details] remove extra adoptref The implementation of createNewPage should return a retained WKPageRef, so the existing code is correct.

Darin Adler

Comment 3 2010-11-11 16:34:02 PST

This is probably a bug in the test program, not WebKit2 itself.

zalan

Comment 4 2010-11-11 23:56:20 PST

ok, thanks for the clarification.

zalan

Comment 5 2010-11-19 06:12:39 PST

Created attachment 74380 [details] retain WKPageRef

Andreas Kling

Comment 6 2010-11-19 15:00:58 PST

Comment on attachment 74380 [details] retain WKPageRef LGTM

WebKit Commit Bot

Comment 7 2010-11-19 22:26:28 PST

The commit-queue encountered the following flaky tests while processing attachment 74380 [details]: fast/profiler/throw-exception-from-eval.html Please file bugs against the tests. These tests were authored by kmccullough@apple.com, oliver@apple.com, and timothy@apple.com. The commit-queue is continuing to process your patch.

WebKit Commit Bot

Comment 8 2010-11-19 22:29:23 PST

Comment on attachment 74380 [details] retain WKPageRef Clearing flags on attachment: 74380 Committed r72468: <http://trac.webkit.org/changeset/72468>

WebKit Commit Bot

Comment 9 2010-11-19 22:29:30 PST

All reviewed patches have been landed. Closing bug.

Note You need to log in before you can comment on or make changes to this bug.