[asterisk-bugs] [JIRA] (ASTERISK-21207) [patch] - Deadlock on fax extension calling ast_async_goto() with locked channel

[Ashley Winters (JIRA)]

    [ https://issues.asterisk.org/jira/browse/ASTERISK-21207?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=204556#comment-204556 ] 

Ashley Winters commented on ASTERISK-21207:
-------------------------------------------

The problem is that {{interpret_t38_parameters}} isn't getting called the way I thought. I expected {{ast_queue_control_data}} to trigger an indicate on chan, which would call {{interpret_t38_parameters}}, but it doesn't. If I modify {{change_t38_state}} to conditionally call {{ast_indicate_data}} instead (based on what flag? or simply !{{ast_channel_bridged}}?), I'd need to show that for every fax interop scenario (send, receive, bridge, gateway) that it still works. That's a tall order.
                
> [patch] - Deadlock on fax extension calling ast_async_goto() with locked channel
> --------------------------------------------------------------------------------
>
>                 Key: ASTERISK-21207
>                 URL: https://issues.asterisk.org/jira/browse/ASTERISK-21207
>             Project: Asterisk
>          Issue Type: Bug
>      Security Level: None
>          Components: Channels/chan_dahdi, Channels/chan_sip/General
>    Affects Versions: 10.7.1, 11.2.1
>         Environment: CentOS 6.3 x86_64
>            Reporter: Ashley Winters
>            Severity: Critical
>         Attachments: fax-deadlock.patch, fax-deadlock-v2.patch, gdb-fax-deadlock.txt
>
>
> On an asterisk system with heavy use of AGI and inbound CNG-detected faxing, occasionally all channel activity will freeze. Running 'core show channels' returns nothing, but the logs continue running with anything except channel activity. Running with 'sip set debug on' shows that chan_sip.c doesn't even claim to be reading packets anymore.
> This deadlock was triggered several times daily across our array of asterisk servers, which process hundreds of faxes and tens of thousands of calls daily.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.asterisk.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira