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This is an automatically generated e-mail. To reply, visit:
<a href="https://reviewboard.asterisk.org/r/1118/">https://reviewboard.asterisk.org/r/1118/</a>
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<p style="margin-top: 0;">On April 28th, 2011, 3:26 a.m., <b>Alec Davis</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;">I sort of see where your coming from releasing the target before the ast_channel_masquerade, but I don't think it's necessary, as I understand it's ast_do_masquerade that requires all locks to be released before its executed.</pre>
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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;">i want to release this lock as soon as possible as the masqurading will be done in another thread i dont need it here so ill drop it and let things happen.</pre>
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<p style="margin-top: 0;">On April 28th, 2011, 3:26 a.m., <b>Alec Davis</b> wrote:</p>
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<a href="https://reviewboard.asterisk.org/r/1118/diff/6/?file=16265#file16265line145" style="color: black; font-weight: bold; text-decoration: underline;">/trunk/apps/app_directed_pickup.c</a>
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(Diff revision 6)
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<td colspan="4"><pre style="font-size: 8pt; line-height: 140%; margin: 0; ">static int pickup_do(struct ast_channel *chan, struct ast_channel *target)</pre></td>
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">target</span> <span class="o">=</span> <span class="n">ast_channel_unref</span><span class="p">(</span><span class="n">target</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;">do we have a ref leak here, particulary when the code path could fail above is ast_answer fails?</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;">Ah indeed ... </pre>
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<p style="margin-top: 0;">On April 28th, 2011, 3:26 a.m., <b>Alec Davis</b> wrote:</p>
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<a href="https://reviewboard.asterisk.org/r/1118/diff/6/?file=16266#file16266line6443" style="color: black; font-weight: bold; text-decoration: underline;">/trunk/main/channel.c</a>
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(Diff revision 6)
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<td colspan="4"><pre style="font-size: 8pt; line-height: 140%; margin: 0; ">int ast_do_masquerade(struct ast_channel *original)</pre></td>
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<td bgcolor="#fdfebc" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">ast_channel_lock</span><span class="p">(</span><span class="n">original</span><span class="p">)<span class="hl">;</span></span></pre></td>
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<td bgcolor="#fdfebc" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "><span class="hl"> </span><span class="k"><span class="hl">while</span></span><span class="hl"> </span><span class="p"><span class="hl">(</span></span><span class="n">ast_channel_<span class="hl">try</span>lock</span><span class="p">(</span><span class="n">original</span><span class="p">)<span class="hl">)</span></span><span class="hl"> </span><span class="p"><span class="hl">{</span></span></pre></td>
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">ao2_unlock</span><span class="p">(</span><span class="n">channels</span><span class="p">);</span></pre></td>
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">usleep</span><span class="p">(</span><span class="mi">1</span><span class="p">);</span></pre></td>
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">ao2_lock</span><span class="p">(</span><span class="n">channels</span><span class="p">);</span></pre></td>
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <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;">The idea of locking the channels container was to stall all other masquerades.</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;">using the chan_pickup_group ao2_callback method the channels container is locked when more than one channel is contesting the pickup ... but the kicker is the order will be wrong in that case channels first then channel we are locking channel then channels this avoidance will still work as follows ...
it will release the channels container until the channel is obtained at this point in the code there could be many contesting it at this point the first one to grab them in the right order will win and all others will be rejected ...
unfortunately i cant find the debug trace that is related to this ....
using the chan_pickup_group callback introduced this deadlock path and would hate it to persist in the clean up you doing.</pre>
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<p>- irroot</p>
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<p>On April 27th, 2011, 8:39 a.m., irroot wrote:</p>
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<div>Review request for Asterisk Developers.</div>
<div>By irroot.</div>
<p style="color: grey;"><i>Updated 2011-04-27 08:39:15</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;">as a companion to 0018825 to aid with the move from call-limits to channel group variables. the problem with pickup and queue is that they manage channels outside the dialplan and need "helpers" to deal with channel groups.
in the case of pickup when a call is placed to a extension with say a "<EXTEN>@called" channel group when it is picked up this needs to be cleared to allow further calls when call waiting is disabled.
exten => s,n,GotoIf($[$[${ GROUP_COUNT(${ARG1}@called)} >= 1] | $[${GROUP_COUNT(${ARG1}@caller)} >= 1] | $[${GROUP_COUNT(${ARG1}@pickup)} >= 1] | $[${GROUP_COUNT(${ARG1}@qagent)} >= 1]]?s-BUSY,1)
where
caller is set when a call is placed.
called is set when a call is received
pickup is set when before calling pickup in the dialplan
qagent is set with patch to queue
Hope this is found to be useful and finds a home in trunk.
not sure what time to put in the "wait for bridge" perhaps there is a better method ?? </pre>
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<b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>
<a href="https://issues.asterisk.org/view.php?id=18830">18830</a>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>/trunk/apps/app_directed_pickup.c <span style="color: grey">(315724)</span></li>
<li>/trunk/main/channel.c <span style="color: grey">(315724)</span></li>
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<p><a href="https://reviewboard.asterisk.org/r/1118/diff/" style="margin-left: 3em;">View Diff</a></p>
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