[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:                     new
Asterisk Version:           1.6.2.13 
JIRA:                        
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:              2010-11-01 08:15 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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 (0128491) bluefox (reporter) - 2010-11-01 08:15
 https://issues.asterisk.org/view.php?id=18165#c128491 
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This just happened to me twice this morning, and here is what I managed to
fetch before I "panicked-restarted" Asterisk.

This was the last warning in the CLI before total deadlock:
[Nov  1 09:07:00] WARNING[6135]: pbx.c:7480 add_pri_lockopt: Unable to
register extension '115', priority -1 in 'hints-parking', already in use

Could this be linked to parking hints, as opposed to ordinary subscribe? 

Issue History 
Date Modified    Username       Field                    Change               
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2010-11-01 08:15 bluefox        Note Added: 0128491                          
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