[asterisk-bugs] [Asterisk 0019397]: [patch] Deadlock in queue handling

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=19397 
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Reported By:                byronclark
Assigned To:                
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Project:                    Asterisk
Issue ID:                   19397
Category:                   Applications/app_queue
Reproducibility:            random
Severity:                   minor
Priority:                   normal
Status:                     new
Asterisk Version:           1.8.4 
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:             2011-06-01 13:11 CDT
Last Modified:              2011-06-02 02:41 CDT
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Summary:                    [patch] Deadlock in queue handling
Description: 
Hit a deadlock on queue handling on a lightly loaded system. Output of
"core show locks" in the Additional Information section.

It looks like BETTER_BACKTRACES doesn't really work when the debug
information lives in a separate (installed) debuginfo package. Backtrace
attached to the ticket.

Here's a quick analysis (thread nubmers are gdb/core show locks):
Thread 20/1081149760
====================
Locks Held
----------
hints (pbx.c:4269)
hint (pbx.c:4270)

Blocking On
-----------
queues (app_queue.c:1563)


Thread 15/1088944448
====================
Locks Held
----------
dialogs (astobj2.c:657)
dialog [sip_pvt] (chan_sip.c:16147)

Blocking On
-----------
hints (pbx.c:4425)


Thread 11/1081657664
====================
Locks Held
----------

Blocking On
-----------
queues (app_queue.c:1463)


Thread 5/1102928192
===================
Locks Held
----------
queues (app_queue.c:4427)

Blocking On
-----------
dialogs (chan_sip.c:7358)


Thread 3/1109186880
===================
Locks Held
----------

Blocking On
-----------
queues (app_queue:2337)
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---------------------------------------------------------------------- 
 (0135634) irroot (reporter) - 2011-06-02 02:41
 https://issues.asterisk.org/view.php?id=19397#c135634 
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Locking the hints container in ast_extension_state_del will ensure proper
locking
order and prevent this lock by allowing the state change to complete
before running how often this happen i suspect its a rare random ?? 

Issue History 
Date Modified    Username       Field                    Change               
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2011-06-02 02:41 irroot         Note Added: 0135634                          
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