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This is an automatically generated e-mail. To reply, visit:
<a href="https://reviewboard.asterisk.org/r/2594/">https://reviewboard.asterisk.org/r/2594/</a>
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<div>Review request for Asterisk Developers.</div>
<div>By Alec Davis.</div>
<p style="color: grey;"><i>Updated June 5, 2013, 10:11 a.m.</i></p>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Changes</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;">Document thread execution pattern, without a lock obtained on the bridgecallno.
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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-21409">ASTERISK-21409</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 (updated)</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;">1). When touching the bridgecallno, we need to lock it.
2). When evaluating the state of 'callno->transferring' of the current leg, we can't change it to READY unless the bridgecallno is locked.
Why, if we are interrupted by the other call leg before 'transferring = TRANSFER_RELEASED', the interrupt will find that it is READY and that the bridgecallno is also READY so Releases the legs.
Then the first call leg in this example, finishes execution, and Releases the legs AGAIN!!!!!!!
A debug captures when it goes wrong.
[May 31 14:44:01] VERBOSE[30820] chan_iax2.c: – Channel 'IAX2/auckland-13262' ready to transfer
[May 31 14:44:01] VERBOSE[30824][C-00000536] chan_iax2.c: – Channel 'IAX2/auckland-20457' ready to transfer
[May 31 14:44:01] VERBOSE[30824][C-00000536] chan_iax2.c: – Releasing IAX2/auckland-20457 and IAX2/auckland-13262
[May 31 14:44:01] VERBOSE[30820] chan_iax2.c: – Releasing IAX2/auckland-13262 and IAX2/auckland-20457
[Jun 5 19:53:43] VERBOSE[25606][C-00000000] chan_iax2.c: -- Channel 'IAX2/auckland-19065' ready to transfer
[Jun 5 19:53:43] VERBOSE[25604][C-00000000] chan_iax2.c: -- Channel 'IAX2/auckland-20047' ready to transfer
[Jun 5 19:53:43] VERBOSE[25606][C-00000000] chan_iax2.c: -- Releasing IAX2/auckland-19065 and IAX2/auckland-20047
[Jun 5 19:53:43] VERBOSE[25604][C-00000000] chan_iax2.c: -- Releasing IAX2/auckland-20047 and IAX2/auckland-19065
[Jun 5 19:53:43] VERBOSE[25606][C-00000000] chan_iax2.c: -- Channel 'IAX2/auckland-19065' finished transfer
[Jun 5 19:53:43] DEBUG[25604][C-00000000] sched.c: Attempted to delete nonexistent schedule entry 17!
[Jun 5 19:53:43] VERBOSE[25604][C-00000000] chan_iax2.c: -- Channel 'IAX2/auckland-20047' finished transfer
A time line of 2 threads interleaving that shows how the Jun 5 capture may have come about.
The execution path seems to switch threads as we print/log data.
thread 25606 thread 25604
====================== =======================
if US == BEGIN
US = READY
"ready to transfer"
if US == BEGIN
US = READY
"ready to transfer"
if THEY == READY
"Releasing .."
if THEY == READY
"Releasing .."
THEY = RELEASED
US = RELEASED
stopstuff(US)
stopstuff(THEM)
"finished transfer"
THEY = RELEASED
US = RELEASED
stopstuff(US)
stopstuff(THEM) (sched.c: Attempted to delete nonexistent schedule entry 17!)
"finished transfer"
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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;">Yes. Between sites. many test calls and real calls being transferred back down the same trunk</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/11/channels/chan_iax2.c <span style="color: grey">(387927)</span></li>
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<p><a href="https://reviewboard.asterisk.org/r/2594/diff/" style="margin-left: 3em;">View Diff</a></p>
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