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This is an automatically generated e-mail. To reply, visit:
<a href="https://reviewboard.asterisk.org/r/4108/">https://reviewboard.asterisk.org/r/4108/</a>
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<p style="margin-top: 0;">On April 10th, 2015, 7:05 p.m. EDT, <b>rmudgett</b> wrote:</p>
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<a href="https://reviewboard.asterisk.org/r/4108/diff/5-6/?file=71780#file71780line492" style="color: black; font-weight: bold; text-decoration: underline;">/trunk/main/astobj2.c</a>
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(Diff revisions 5 - 6)
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<td colspan="4"><pre style="font-size: 8pt; line-height: 140%; margin: 0; ">static int internal_ao2_ref(void *user_data, int delta, const char *file, int line, const char *func)</pre></td>
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "><span class="tb"> </span><span class="tb"> </span><span class="cm">/* This must be done after destructor_fn finishes. It is possible this</span></pre></td>
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "><span class="cm"><span class="tb"> </span><span class="tb"> </span> * unref will destroy weakproxy and we need to ensure it is safe for</span></pre></td>
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "><span class="cm"><span class="tb"> </span><span class="tb"> </span> * destructor_fn to read values that are stored by the weakproxy. */</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;">The comment doesn't make sense. How is destructor_fn supposed to access values in the weak proxy? The real object is no longer linked with the weakproxy.</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;">The following is allowed and a reasonable thing to do:
weakproxy->name = ast_strdup(name);
realobj->name = weakproxy->name;
The idea is that weakproxy has to own storage of any shared fields since realobj could be destroyed at any time. So if the destructor uses realobj->name, it is accessing memory that is owned by the weakproxy.</pre>
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<p>- Corey</p>
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<p>On April 3rd, 2015, 12:58 p.m. EDT, Corey Farrell wrote:</p>
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<div>Review request for Asterisk Developers, George Joseph and rmudgett.</div>
<div>By Corey Farrell.</div>
<p style="color: grey;"><i>Updated April 3, 2015, 12:58 p.m.</i></p>
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<b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>
<a href="https://issues.asterisk.org/jira/browse/ASTERISK-24936">ASTERISK-24936</a>
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<b style="color: #575012; font-size: 10pt;">Repository: </b>
Asterisk
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<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;">This implements "weak" references. The weakproxy object is a real ao2 with normal reference counting of its own. When a weakproxy is pointed to a normal object they hold references to each other. The normal object is automatically freed when a single reference remains (the weakproxy). The weakproxy also supports subscriptions that will notify callbacks when it does not point to any real object.</pre>
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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;">Ran the included test with REF_DEBUG enabled under valgrind. No reference leaks or improper memory access. Though this does not test for races, I don't know of an automated way to do that.</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>/trunk/tests/test_astobj2_weaken.c <span style="color: grey">(PRE-CREATION)</span></li>
<li>/trunk/main/astobj2.c <span style="color: grey">(433964)</span></li>
<li>/trunk/include/asterisk/astobj2.h <span style="color: grey">(433964)</span></li>
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<p><a href="https://reviewboard.asterisk.org/r/4108/diff/" style="margin-left: 3em;">View Diff</a></p>
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