[asterisk-bugs] [Asterisk 0014639]: Asterisk CPU usage 100% (deadlock?) when using Queue() with Local channels

[Asterisk Bug Tracker]

The following issue has been UPDATED. 
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https://issues.asterisk.org/view.php?id=14639 
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Reported By:                coolmig
Assigned To:                
====================================================================== 
Project:                    Asterisk
Issue ID:                   14639
Category:                   Channels/chan_local
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     closed
Target Version:             1.4.27
Asterisk Version:           SVN 
JIRA:                        
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
Resolution:                 no change required
Fixed in Version:           
====================================================================== 
Date Submitted:             2009-03-10 12:26 CDT
Last Modified:              2009-09-24 09:33 CDT
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Summary:                    Asterisk CPU usage 100% (deadlock?) when using
Queue() with Local channels
Description: 
I was testing a dialer I'm making, and found this situation: when I dial
more than one call to an agent using Local channels (busy with one call and
one or more in the queue), Asterisk goes 100% CPU all the time until the
queued calls get answered or hangup.

Core show locks shows this:

=======================================================================
=== Currently Held Locks ==============================================
=======================================================================
===
=== <file> <line num> <function> <lock name> <lock addr> (times locked)
===
=== Thread ID: 3077847952 (pbx_thread           started at [ 2645] pbx.c
ast_pbx_start())
=== ---> Waiting for Lock https://issues.asterisk.org/view.php?id=0
(chan_agent.c): MUTEX 2252 __login_exec
&p->app_lock 0x93d59d4 (1)
=== --- ---> Locked Here: chan_agent.c line 1080 (agent_new)
=== -------------------------------------------------------------------
===
=== Thread ID: 3073665936 (pbx_thread           started at [ 2645] pbx.c
ast_pbx_start())
=== ---> Lock https://issues.asterisk.org/view.php?id=0 (chan_agent.c): MUTEX
1080 agent_new &p->app_lock
0x93d59d4 (1)
=== -------------------------------------------------------------------
===
=== Thread ID: 3075632016 (pbx_thread           started at [ 2645] pbx.c
ast_pbx_start())
=== ---> Tried and failed to get Lock https://issues.asterisk.org/view.php?id=0
(chan_local.c): MUTEX 186
local_queue_frame (channel lock) 0x9464470 (0)
=== -------------------------------------------------------------------
===
=======================================================================

If I hangup the initial agent call, if takes a long time for the Queue to
deliver the other call to the agent, while the agent is with no call, core
show locks shows this:

=======================================================================
=== Currently Held Locks ==============================================
=======================================================================
===
=== <file> <line num> <function> <lock name> <lock addr> (times locked)
===
=== Thread ID: 3077847952 (pbx_thread           started at [ 2645] pbx.c
ast_pbx_start())
=== ---> Lock https://issues.asterisk.org/view.php?id=0 (chan_agent.c): MUTEX
2252 __login_exec &p->app_lock
0x93d59d4 (1)
=== -------------------------------------------------------------------
===
=== Thread ID: 3076860816 (pbx_thread           started at [ 2645] pbx.c
ast_pbx_start())
=== ---> Tried and failed to get Lock https://issues.asterisk.org/view.php?id=0
(chan_local.c): MUTEX 186
local_queue_frame (channel lock) 0x945d820 (0)
=== -------------------------------------------------------------------
===
=======================================================================

When the queued call finally is delivered to the agent, core show locks
shows this, and the 100% usage stops:

=======================================================================
=== Currently Held Locks ==============================================
=======================================================================
===
=== <file> <line num> <function> <lock name> <lock addr> (times locked)
===
=== Thread ID: 3077847952 (pbx_thread           started at [ 2645] pbx.c
ast_pbx_start())
=== ---> Waiting for Lock https://issues.asterisk.org/view.php?id=0
(chan_agent.c): MUTEX 2252 __login_exec
&p->app_lock 0x93d59d4 (1)
=== --- ---> Locked Here: chan_agent.c line 1080 (agent_new)
=== -------------------------------------------------------------------
===
=== Thread ID: 3075632016 (pbx_thread           started at [ 2645] pbx.c
ast_pbx_start())
=== ---> Lock https://issues.asterisk.org/view.php?id=0 (chan_agent.c): MUTEX
1080 agent_new &p->app_lock
0x93d59d4 (1)
=== -------------------------------------------------------------------
===
=======================================================================
====================================================================== 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2009-09-24 09:33 lmadsen        Asterisk Version         1.4.22 => SVN       
2009-09-24 09:33 lmadsen        Target Version           1.4.28 => 1.4.27    
======================================================================