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This is an automatically generated e-mail. To reply, visit:
<a href="http://git.reviewboard.kde.org/r/107573/">http://git.reviewboard.kde.org/r/107573/</a>
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<p style="margin-top: 0;">On December 5th, 2012, 2:16 a.m., <b>Simeon Bird</b> wrote:</p>
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<a href="http://git.reviewboard.kde.org/r/107573/diff/1/?file=97142#file97142line54" style="color: black; font-weight: bold; text-decoration: underline;">libnepomukcore/resource/resource.cpp</a>
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(Diff revision 1)
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">Q_ASSERT_X</span><span class="p">(</span> <span class="n">ResourceManager</span><span class="o">::</span><span class="n">instance</span><span class="p">(),</span> <span class="s">"Nepomuk2::Resource"</span><span class="p">,</span></pre></td>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Might it be better to simply return some empty resource, instead of asserting?
In 292996 , we just figured out that a Resource can continue being accessed after QApplication has been destroyed, because QRunnable cannot be cancelled. If that thread, instead of accessing the Resource, had constructed a new Resource, with this code we would crash on exit in a release build.
Since we would likely only hit the race in a release build, we would get another difficult-to-debug crash on exit.</pre>
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<p>On December 6th, 2012, 8:42 a.m., <b>Vishesh Handa</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Maybe I should remove the assert? That empty resource doesn't really cause any harm. What do you think?</pre>
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<p>On December 9th, 2012, 1:16 a.m., <b>Simeon Bird</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">If it were me, I would remove the assert entirely since, as you say, the empty resource doesn't really cause any harm, and if it is left in we could easily get bugs reported from some user accidentally compiling in debug mode and crashing kontact (or whatever).
But it's up to you - I can see that the assert might be useful if it occurred somewhere other than application quit.</pre>
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<p>On December 9th, 2012, 1:14 p.m., <b>Vishesh Handa</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Removed the assert, and added a kError() message instead :)</pre>
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<pre style="margin-left: 1em; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Great :)</pre>
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<p>- Simeon</p>
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<p>On December 6th, 2012, 8:40 a.m., Vishesh Handa wrote:</p>
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<div>Review request for Nepomuk, Sebastian Trueg and Simeon Bird.</div>
<div>By Vishesh Handa.</div>
<p style="color: grey;"><i>Updated Dec. 6, 2012, 8:40 a.m.</i></p>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
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<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;"> ResourceWatcher: Do no create a new ResourceManager on quit
The ResourceManager contains a ResourceWatcher. This ResourceWatcher is
initialized only when a Resource class requires it. On destruction it
calls ResourceWatcher::stop, which tries to disconnect it from
ResourceManager::nepomukSystemStarted signal.
The problem arises when the application is exiting, and the
ResourceManager (being a child of QCoreApplication) is being destroyed.
It in turn destroys the ResourceWatcher, which calls
ResourceWatcher::stop, which calls ResourceManager::instance() which
results in the creation of a new ResourceManager whose parent is
QCoreApplication::instance, which is 0, cause the application is
shutting down.
This whole extra ResourceManager being allocated is not required and can
be avoided by checking if QCoreApplication != 0, in
ResourceManager::instance.
Also, since ResourceManager::instance() can now return 0. I've added an
assert check in the Resource class.
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
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<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;">Added breakpoints in gdb, and wrote a simple application. The extra ResourceManager is no longer being created.</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>libnepomukcore/datamanagement/resourcewatcher.cpp <span style="color: grey">(a09b646)</span></li>
<li>libnepomukcore/resource/resource.cpp <span style="color: grey">(4601eba)</span></li>
<li>libnepomukcore/resource/resourcemanager.cpp <span style="color: grey">(457c042)</span></li>
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<p><a href="http://git.reviewboard.kde.org/r/107573/diff/" style="margin-left: 3em;">View Diff</a></p>
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