[asterisk-bugs] [Asterisk 0018310]: hint state changes deadlock/race

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=18310 
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Reported By:                one47
Assigned To:                
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Project:                    Asterisk
Issue ID:                   18310
Category:                   Core/PBX
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     new
Asterisk Version:           1.6.2.14 
JIRA:                       SWP-2541 
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:             2010-11-15 12:19 CST
Last Modified:              2010-11-17 00:55 CST
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Summary:                    hint state changes deadlock/race
Description: 
VERY similar to https://issues.asterisk.org/view.php?id=18165, but this is a
different deadlock path, so I have
raised a separate report.

Thread 1: taskprocessor  -> handle_statechange
    Lock order = conlock, hints, hint, pvt
Thread 2: chan_sip.c:  handle_request_do -> handle_response_notify
    Lock order = pvt, conlock

Thread2 only gets into the conlock if STATECHANGEQUEUE is true, ie. there
are rapid state changes happening on a subscribed hint.
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 (0128910) MKemner (reporter) - 2010-11-17 00:55
 https://issues.asterisk.org/view.php?id=18310#c128910 
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I have been chasing this exact same fault for weeks, on 1.8

I was running 1.8.0, and as of two days ago I upgraded to
SVN-branch-1.8-r294989M to try and resolve this issue - at the same time I
enabled thread debugging support.  I just had it deadlock again, and have
uploaded the output to 'core show locks' - which shows the exact same
situation as described by one47.

Thread 1
 holds ast_rdlock_contexts &conlock
 holds handle_statechange hints
 holds handle_statechange hint
  waiting for cb_extensionstate
   Locked Here: chan_sip.c line 7428 (find_call)
Thread 2
 holds handle_request_do &netlock
 holds find_call sip_pvt_ptr
  waiting for ast_rdlock_contexts &conlock
   Locked Here: pbx.c line 9911 (ast_rdlock_contexts) 

Issue History 
Date Modified    Username       Field                    Change               
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2010-11-17 00:55 MKemner        Note Added: 0128910                          
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