[prev in list] [next in list] [prev in thread] [next in thread]
List: kde-core-devel
Subject: Re: Review Request: Fix a VLC crash by delaying object deletion to
From: "Dawit Alemayehu" <adawit () kde ! org>
Date: 2011-04-12 22:22:10
Message-ID: 20110412222210.26027.44970 () vidsolbach ! de
[Download RAW message or body]
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://git.reviewboard.kde.org/r/100577/
-----------------------------------------------------------
(Updated April 12, 2011, 10:22 p.m.)
Review request for kdelibs and Thiago Macieira.
Changes
-------
Thiago,
A reminder for you to look into this crash when you get a chance[1]. Otherwise, we \
would have to commit the workaround patch posted in this review.
[1] http://lists.kde.org/?l=kde-core-devel&m=129693527318658&w=2
Summary
-------
As described in the bug report when opening the file dialog, canceling it and exiting \
VLC causes the application to seg fault. The backtraces posted in the bug report \
shows that the crash happens somewhere in QtDBus and I get a similar backtrace when \
using v1.1.7 of this application.
When I looked into this issue what I discovered was that only KIO classes that \
register themselves with QtDBus cause the crash. I only found that out because fixing \
the crash in KIO::Scheduler by defering its deletion using deleteLater() did not \
prevent the application from still crashing on exit. However, the crash had moved to \
another location, KBookmarkManager. The only common thing between the crash at \
KBookmarkmanager and KIO::Scheduler was that in both cases the backtrace shows QtDBus \
attempting to invoke or access some method or slot in the object that was just \
destroyed. At this point I decided to check how many other classes in KIO register \
themselves with QtDBS and found only one and applied the same change to all three, \
defer deletion of any object registered with QtDBus using QObject::deleteLater.
Anyhow, I have no idea why the crashes are only seen with this application. I was not \
able to duplicate the crash using the same sequences in another Qt only app, Arora \
and none of the KDE applications I tried.
This addresses bug 234484.
http://bugs.kde.org/show_bug.cgi?id=234484
Diffs
-----
kio/kio/scheduler.cpp d5fab85
kio/bookmarks/kbookmarkmanager.cc 9086fd2
kio/kio/fileundomanager.cpp ca1cbbb
Diff: http://git.reviewboard.kde.org/r/100577/diff
Testing
-------
Thanks,
Dawit
[Attachment #3 (text/html)]
<html>
<body>
<div style="font-family: Verdana, Arial, Helvetica, Sans-Serif;">
<table bgcolor="#f9f3c9" width="100%" cellpadding="8" style="border: 1px #c9c399 \
solid;"> <tr>
<td>
This is an automatically generated e-mail. To reply, visit:
<a href="http://git.reviewboard.kde.org/r/100577/">http://git.reviewboard.kde.org/r/100577/</a>
</td>
</tr>
</table>
<br />
<table bgcolor="#fefadf" width="100%" cellspacing="0" cellpadding="8" \
style="background-image: \
url('http://git.reviewboard.kde.org/media/rb/images/review_request_box_top_bg.png'); \
background-position: left top; background-repeat: repeat-x; border: 1px black \
solid;"> <tr>
<td>
<div>Review request for kdelibs and Thiago Macieira.</div>
<div>By Dawit Alemayehu.</div>
<p style="color: grey;"><i>Updated April 12, 2011, 10:22 p.m.</i></p>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Changes</h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: \
1px solid #b8b5a0"> <tr>
<td>
<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;">Thiago,
A reminder for you to look into this crash when you get a chance[1]. Otherwise, we \
would have to commit the workaround patch posted in this review.
[1] http://lists.kde.org/?l=kde-core-devel&m=129693527318658&w=2</pre>
</td>
</tr>
</table>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: \
1px solid #b8b5a0"> <tr>
<td>
<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;">As described in the bug report when opening the file dialog, canceling \
it and exiting VLC causes the application to seg fault. The backtraces posted in the \
bug report shows that the crash happens somewhere in QtDBus and I get a similar \
backtrace when using v1.1.7 of this application.
When I looked into this issue what I discovered was that only KIO classes that \
register themselves with QtDBus cause the crash. I only found that out because fixing \
the crash in KIO::Scheduler by defering its deletion using deleteLater() did not \
prevent the application from still crashing on exit. However, the crash had moved to \
another location, KBookmarkManager. The only common thing between the crash at \
KBookmarkmanager and KIO::Scheduler was that in both cases the backtrace shows QtDBus \
attempting to invoke or access some method or slot in the object that was just \
destroyed. At this point I decided to check how many other classes in KIO register \
themselves with QtDBS and found only one and applied the same change to all three, \
defer deletion of any object registered with QtDBus using QObject::deleteLater.
Anyhow, I have no idea why the crashes are only seen with this application. I was not \
able to duplicate the crash using the same sequences in another Qt only app, Arora \
and none of the KDE applications I tried.</pre> </td>
</tr>
</table>
<div style="margin-top: 1.5em;">
<b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>
<a href="http://bugs.kde.org/show_bug.cgi?id=234484">234484</a>
</div>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">
<li>kio/kio/scheduler.cpp <span style="color: grey">(d5fab85)</span></li>
<li>kio/bookmarks/kbookmarkmanager.cc <span style="color: \
grey">(9086fd2)</span></li>
<li>kio/kio/fileundomanager.cpp <span style="color: grey">(ca1cbbb)</span></li>
</ul>
<p><a href="http://git.reviewboard.kde.org/r/100577/diff/" style="margin-left: \
3em;">View Diff</a></p>
</td>
</tr>
</table>
</div>
</body>
</html>
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic