[asterisk-bugs] [Asterisk 0018165]: hint state changes deadlock problem

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=18165 
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Reported By:                antonio
Assigned To:                
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Project:                    Asterisk
Issue ID:                   18165
Category:                   Core/PBX
Reproducibility:            have not tried
Severity:                   major
Priority:                   normal
Status:                     acknowledged
Asterisk Version:           1.6.2.13 
JIRA:                       SWP-2495 
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2010-10-19 13:45 CDT
Last Modified:              2010-11-03 12:47 CDT
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Summary:                    hint state changes deadlock problem
Description: 
What happens is there are two threads that lock resources in a different
order causing a deadlock.

The threads are:

1. from taskprocessor handle_statechange() is called. This one locks
ast_rdlock_contexts, and then eventually call cb_extensionstate() which
immediately does a sip_pvt_lock()

2. do_monitor calls sipsock_read() which calls handle_request_do() which
calls find_call(), which does a sip_pvt_lock() too. The incoming request is
a subscription, so it calls ast_get_hint(), which calls
ast_hint_extension() which calls ast_rdlock_contexts(). Deadlock.

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Relationships       ID      Summary
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has duplicate       0018205 PBX hangup
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 (0128593) jpeeler (administrator) - 2010-11-03 12:47
 https://issues.asterisk.org/view.php?id=18165#c128593 
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I created a branch for this here:
http://svn.digium.com/svn/asterisk/team/jpeeler/issue18165

I'm also attaching the patch that will hopefully apply to later versions
(it is 1.4 based). 

Issue History 
Date Modified    Username       Field                    Change               
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2010-11-03 12:47 jpeeler        Note Added: 0128593                          
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