[asterisk-bugs] [Asterisk 0017216]: Deadlock between ast_hangup and pri_dchannel

[Asterisk Bug Tracker]

The following issue has been SUBMITTED. 
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https://issues.asterisk.org/view.php?id=17216 
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Reported By:                lmsteffan
Assigned To:                
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Project:                    Asterisk
Issue ID:                   17216
Category:                   Channels/chan_dahdi
Reproducibility:            random
Severity:                   major
Priority:                   normal
Status:                     new
Asterisk Version:           SVN 
JIRA:                        
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!): 236802 
Request Review:              
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Date Submitted:             2010-04-20 19:49 CDT
Last Modified:              2010-04-20 19:49 CDT
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Summary:                    Deadlock between ast_hangup and pri_dchannel
Description: 
I think what causes the deadlock is the following :

Ast_hangup performs a lock of the channel then, through dahdi_hangup,
tries to lock the private (Dahdi) part of the channel.

Meanwhile, pri_dchannel first seizes the private part of the channel,
then, in ast_softhangup_nolock, tries to lock the channel that owns this
private part.

A deadlock occurs as both threads attempt to seize both deadlocks in
reverse order.

I include a full trace and a snapshot of the locks.


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Issue History 
Date Modified    Username       Field                    Change               
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2010-04-20 19:49 lmsteffan      New Issue                                    
2010-04-20 19:49 lmsteffan      Asterisk Version          => SVN             
2010-04-20 19:49 lmsteffan      Regression                => No              
2010-04-20 19:49 lmsteffan      SVN Branch (only for SVN checkouts, not tarball
releases) => N/A             
2010-04-20 19:49 lmsteffan      SVN Revision (number only!) => 236802          
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