[asterisk-dev] [Code Review] chan_sip REFER deadlock fixes

[David Vossel]

-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviewboard.asterisk.org/r/1339/#review4051
-----------------------------------------------------------


I understand this issue is sort of a rabbit hole with locking, but I need to limit the scope of what I am going to address in this fix to the deadlock issues directly resulting from problems in the handle_request_refer() function.  The potential deadlocks you have pointed out in the local_attended_transfer function involve problems with the preconditions to that function.

- David


On Aug. 2, 2011, 4:28 p.m., David Vossel wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviewboard.asterisk.org/r/1339/
> -----------------------------------------------------------
> 
> (Updated Aug. 2, 2011, 4:28 p.m.)
> 
> 
> Review request for Asterisk Developers.
> 
> 
> Summary
> -------
> 
> handle_request_refer() is a complete mess when it comes to locking.  A deadlock occurs, we fix it, and then it moves somewhere else.  This patch attempts to resolve all the possible locking inversion issues that can occur in this function.
> 
> 
> This addresses bug ASTERISK-18082.
>     https://issues.asterisk.org/jira/browse/ASTERISK-18082
> 
> 
> Diffs
> -----
> 
>   /branches/1.8/channels/chan_sip.c 330671 
> 
> Diff: https://reviewboard.asterisk.org/r/1339/diff
> 
> 
> Testing
> -------
> 
> I tested refer using a snom phone with blind transfer, but that is not very impressive.
> 
> James Van Vleet has tested this code using a load testing tool that was capable of exposing all sorts of problems.  He has reported that his test is running without issue using this iteration of the patch.  Given what it was capable of exposing earlier, I am confident in these test results.
> 
> 
> Thanks,
> 
> David
> 
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.digium.com/pipermail/asterisk-dev/attachments/20110812/af3cddb9/attachment.htm>