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This is an automatically generated e-mail. To reply, visit:
<a href="https://reviewboard.asterisk.org/r/1712/">https://reviewboard.asterisk.org/r/1712/</a>
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<p style="margin-top: 0;">On February 3rd, 2012, 10:28 a.m., <b>rmudgett</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;">Yes holding the channels container lock is not necessary.
However, your example about the audiohooks could still cause problems because the channel lock is held and many ao2_callbacks over the channels container also lock each channel in turn.
Would moving the audiohook and framehook destruction after the channel is unlinked be needed to completely avoid your example holding up the system?</pre>
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<p>On February 3rd, 2012, 10:59 a.m., <b>Russell Bryant</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;">That's a great point, Richard. I'll make that change.</pre>
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<p>On February 3rd, 2012, 2:50 p.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;">The ao2_lock(channels) in ast_hangup() got added with the call pickup race.
https://reviewboard.asterisk.org/r/1400/
Hopefully, it won't be re-broken,</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;">Thanks Alec, it likely would break pickup again.
The pickup fix depends on the ZOMBIE flag being set. ast_hangup() needs to either masquerade or get the ZOMBIE flag set before releasing the channel lock.
The ZOMBIE flag likely needs to be set earlier in the hangup.</pre>
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<p>- rmudgett</p>
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<p>On February 3rd, 2012, 9:58 a.m., Russell Bryant wrote:</p>
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<div>Review request for Asterisk Developers.</div>
<div>By Russell Bryant.</div>
<p style="color: grey;"><i>Updated Feb. 3, 2012, 9:58 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;">This patch removes some unnecessary locking of the channels container in ast_hangup(). The reason this came up is that this lock can very quickly block the entire system. If any of the channel cleanup code decides to block, it causes a problem for the whole system. For example, when audiohooks get destroyed, if that blocks for a while waiting on the mixmonitor thread to exit because it's busy blocking on some I/O, it causes a problem for many other threads in the meantime.</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 under load in a test environment, about 1/2 million calls</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>/branches/1.8/main/channel.c <span style="color: grey">(353961)</span></li>
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<p><a href="https://reviewboard.asterisk.org/r/1712/diff/" style="margin-left: 3em;">View Diff</a></p>
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