[asterisk-bugs] [Asterisk 0012512]: Deadlock during processing of IAM

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A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=12512 
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Reported By:                arnd
Assigned To:                mattf
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Project:                    Asterisk
Issue ID:                   12512
Category:                   Channels/chan_zap
Reproducibility:            sometimes
Severity:                   block
Priority:                   normal
Status:                     acknowledged
Asterisk Version:           SVN 
SVN Branch (only for SVN checkouts, not tarball releases): 1.6.0 
SVN Revision (number only!): 114560 
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             04-24-2008 06:00 CDT
Last Modified:              04-25-2008 13:31 CDT
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Summary:                    Deadlock during processing of IAM
Description: 
During high call volumes, the SS7 Link goes down. 
The reason is, that there is a potenial Deadlock Situation in chan_zap.

Below is the relevant (as I can see) part of the CLI commando core show
locks.

Afer some looks inside the Code i came to teh opinion, that there is a
race-condition in the function ss7_start_call.

In the function, a new channel gets created with the flag, to start pbx on
that channel.
c = zt_new(p, AST_STATE_RING, 1, SUB_REAL, law, 0);

After that, the Channel gets a log of SS7 related Variables set. During
these operations, the deadlock happens.

So, may it help, to create the channel, without starting the pbx on it,
and call ast_pbx_run(c) after setting the variables ?




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---------------------------------------------------------------------- 
 mattf - 04-25-08 13:31  
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I just uploaded a patch that I think will fix the problem.  Please test it
and see if there are anymore issues. 

Issue History 
Date Modified   Username       Field                    Change               
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04-25-08 13:31  mattf          Note Added: 0086028                          
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