[asterisk-dev] Strange deadlock

Miguel Molina mmolina at millenium.com.co
Fri Nov 14 14:45:51 CST 2008

Hello everyone,

This is my first post here. I would like to report a strange deadlock
that ocurred to the asterisk running in a Call Center. It was rock 
stable 15 days before the problem. It receives calls from another 
asterisk through a SIP trunk.


Agent/202 was logged in and receiving a transferred call from
Local/7416 at electr-gap-b39e,2. That call ended, but the agent was like
having the call, with no audio. The agent hungup the login call on the 
softphone but could not login again (agent already logged in).

  From the CLI viewpoint, if I do a "show channels" command, the command
on some channel half the output leaving the CLI unusable to any commands 
except exit. I have to exit
and reenter the CLI to have it working again.

The "show queues" command shows the Agent 202 like this: "Agent/202
logged on SIP/204-086e0bd0 talking to Local/7416 at electr-gap-b39e,2".
If I try to logoff the Agent 202 with "agent logoff Agent/202", shows
"logging out Agent/202" but the agent never gets logged off.
If I try to hangup the SIP/204-086e0bd0 channel, shows "requesting
hangup on SIP/204-086e0bd0", but the agent never gets logged off.
If I try to autocomplete on commands like "show channel <tab>", the CLI
freezes entirely and I have to restart my SSH session to the server and
enter back to the CLI to have it working again. This also stops any
manager interface processing so external process can't get asterisk
information. It happened that manager interface started working again
after a few minutes after the CLI autocompletion freeze.

The only way to get rid of the stuck channel and agent login is to
restart the asterisk losing all calls and getting all agents logged back

I did a gdb debug on the running asterisk that is attached to this mail 
compressed in .tar.gz format.
It is version 1.4.22, but it does not have the DEBUG_THREADS or
DONT_OPTIMIZE compiler flags yet, so I don't have a "core show locks"
output. Could someone please help me check the debug so we can catch
what is causing the deadlock? If this is a bug, how can I report it to

Thanks already,

Ing. Miguel Molina
Grupo de Tecnología
Millenium Phone Center
PBX: (+57 1)6500800 ext. 1201
Fax: (+57 1)6500816
Móvil: (+57)3138873587
-------------- next part --------------
A non-text attachment was scrubbed...
Name: gdb-deadlock-agentes-20081114-135400.txt.tar.gz
Type: application/x-gzip
Size: 14854 bytes
Desc: not available
Url : http://lists.digium.com/pipermail/asterisk-dev/attachments/20081114/6000bc2f/attachment.bin 

More information about the asterisk-dev mailing list