[asterisk-bugs] [Asterisk 0015787]: [patch] chan_local deadlock

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=15787 
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Reported By:                tim_ringenbach
Assigned To:                tilghman
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Project:                    Asterisk
Issue ID:                   15787
Category:                   Channels/chan_local
Reproducibility:            random
Severity:                   minor
Priority:                   normal
Status:                     closed
Asterisk Version:           1.4.26.1 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
Resolution:                 fixed
Fixed in Version:           
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Date Submitted:             2009-08-27 19:03 CDT
Last Modified:              2009-08-31 11:19 CDT
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Summary:                    [patch] chan_local deadlock
Description: 
I've experienced a chan_local deadlock that wasn't in 1.4.24 but is in
1.4.25.1 and 1.4.26.1. I see threads stuck like this:

  28 process 7567  0x00007fb9de31a174 in __lll_lock_wait () from
/lib/libpthread.so.0
  27 process 7568  0x00007fb9de31a174 in __lll_lock_wait () from
/lib/libpthread.so.0
  26 process 7569  0x00007fb9de31a174 in __lll_lock_wait () from
/lib/libpthread.so.0
  25 process 7570  0x00007fb9de31a174 in __lll_lock_wait () from
/lib/libpthread.so.0
  24 process 7571  0x00007fb9de31a174 in __lll_lock_wait () from
/lib/libpthread.so.0


And this backtrace from them:
https://issues.asterisk.org/view.php?id=0  0x00007fb9de31a174 in __lll_lock_wait
() from /lib/libpthread.so.0
https://issues.asterisk.org/view.php?id=1  0x00007fb9de315b23 in _L_lock_261 ()
from /lib/libpthread.so.0
https://issues.asterisk.org/view.php?id=2  0x00007fb9de3154e8 in
pthread_mutex_lock () from /lib/libpthread.so.0
https://issues.asterisk.org/view.php?id=3  0x00007fb9cfe1840b in local_write
(ast=0x7fb9d0019cf0, f=0x80) at
chan_local.c:340
https://issues.asterisk.org/view.php?id=4  0x00007fb9de31f3d1 in ?? () from
/lib/libpthread.so.0
https://issues.asterisk.org/view.php?id=5  0x0000000000000001 in ?? ()
https://issues.asterisk.org/view.php?id=6  0x000000004342d1e0 in ?? ()
https://issues.asterisk.org/view.php?id=7  0x000000004342ce60 in ?? ()
https://issues.asterisk.org/view.php?id=8  0x0000000000000001 in ?? ()
https://issues.asterisk.org/view.php?id=9  0x00007fb9dd90aee3 in siglongjmp ()
from /lib/libc.so.6
https://issues.asterisk.org/view.php?id=10 0x00007fb9de319ee8 in unwind_stop ()
from /lib/libpthread.so.0
https://issues.asterisk.org/view.php?id=11 0x00000000004388a9 in ast_request
(type=0x7fb9c80b9cf0 "Local",
format=64, data=0x7fb9c80b9d40, cause=0x4342cd18) at channel.c:3381

(manually killed with sig 11 to ge trace, it never crashed on its own)

And I think I've found the problem, which I'll attach as a patch.
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---------------------------------------------------------------------- 
 (0109857) svnbot (reporter) - 2009-08-31 11:19
 https://issues.asterisk.org/view.php?id=15787#c109857 
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Repository: asterisk
Revision: 214945

_U  trunk/
U   trunk/channels/chan_local.c

------------------------------------------------------------------------
r214945 | tilghman | 2009-08-31 11:19:16 -0500 (Mon, 31 Aug 2009) | 14
lines

Merged revisions 214940 via svnmerge from 
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r214940 | tilghman | 2009-08-31 11:16:52 -0500 (Mon, 31 Aug 2009) | 7
lines
  
  Also unlock the "other" channel, when returning, due to glare.
  (closes issue https://issues.asterisk.org/view.php?id=15787)
   Reported by: tim_ringenbach
   Patches: 
         chan_local.diff uploaded by tim ringenbach (license 540)
   Tested by: tim_ringenbach
........

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http://svn.digium.com/view/asterisk?view=rev&revision=214945 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2009-08-31 11:19 svnbot         Checkin                                      
2009-08-31 11:19 svnbot         Note Added: 0109857                          
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