Summary:	ASTERISK-14058: [patch] Bad locking logic on res_config_mysql.c
Reporter:	Cristian Dimache (cristiandimache)	Labels:
Date Opened:	2009-05-03 14:09:26	Date Closed:	2009-05-14 14:21:21
Priority:	Major	Regression?	No
Status:	Closed/Complete	Components:	Addons/res_config_mysql
Versions:		Frequency of Occurrence
Related Issues:
Environment:		Attachments:	( 0) 20090514__issue15090.diff.txt
Description:	store_mysql calls find_database(), which locks the database handle. Then, it calls internal_require(), which calls require_mysql(), which calls find_table(), which calls find_database(), thus requesting a new lock on the database handle. I could be wrong in the call chain, but the result is always the same: Asterisk stops waiting for a lock to be released. ****** ADDITIONAL INFORMATION ****** Problem occurs on version 1.6.1.0 of asterisk-addons, but I think it is there since 1.6.1-rc1
Comments:	By: Tilghman Lesher (tilghman) 2009-05-04 12:29:32 Have you tried this and gotten a lockup, or are you speculating? By: Cristian Dimache (cristiandimache) 2009-05-04 12:41:01 I've tried it. A patch is a little above my skills and spare time, but I added some debug and reached at that conclusion. By: Tilghman Lesher (tilghman) 2009-05-04 12:53:45 Okay, then compile with 'DEBUG_THREADS' and obtain a 'core show locks' when this occurs. A lockup should not occur, because we're using recursive locks in Asterisk.  The fact that a mutex was already locked by our same thread isn't relevant to our programming model. By: Cristian Dimache (cristiandimache) 2009-05-11 00:58:17 I should be able to test it tonight or in about 48h. Thanks for waiting. By: Tilghman Lesher (tilghman) 2009-05-14 09:01:05 Patch uploaded.  Found with a 'core show locks' in related issue ASTERISK-14113.  Please test and verify. By: Cristian Dimache (cristiandimache) 2009-05-14 13:37:06 Looks okay. BTW, is ASTERISK-14113 private? Should it be? By: Leif Madsen (lmadsen) 2009-05-14 13:39:58 Yes, it is marked private because the reporter requested it since it contained some personal information. By: Digium Subversion (svnbot) 2009-05-14 14:17:01 Repository: asterisk-addons Revision: 910 U   trunk/res/res_config_mysql.c ------------------------------------------------------------------------ r910 | tilghman | 2009-05-14 14:17:00 -0500 (Thu, 14 May 2009) | 7 lines Change database list to be rwlist locks, to avoid a potential deadlock between 2 readers. (closes issue ASTERISK-14058, related to issue ASTERISK-14113) Reported by: cristiandimache Patches:       20090514__issue15090.diff.txt uploaded by tilghman (license 14) Tested by: cristiandimache ------------------------------------------------------------------------ http://svn.digium.com/view/asterisk-addons?view=rev&revision=910 By: Digium Subversion (svnbot) 2009-05-14 14:19:51 Repository: asterisk-addons Revision: 913 _U  branches/1.6.1/ U   branches/1.6.1/res/res_config_mysql.c ------------------------------------------------------------------------ r913 | tilghman | 2009-05-14 14:19:50 -0500 (Thu, 14 May 2009) | 14 lines Merged revisions 910 via svnmerge from https://origsvn.digium.com/svn/asterisk-addons/trunk ........  r910 | tilghman | 2009-05-14 14:16:53 -0500 (Thu, 14 May 2009) | 7 lines    Change database list to be rwlist locks, to avoid a potential deadlock between 2 readers.  (closes issue ASTERISK-14058, related to issue ASTERISK-14113)   Reported by: cristiandimache   Patches:         20090514__issue15090.diff.txt uploaded by tilghman (license 14)   Tested by: cristiandimache ........ ------------------------------------------------------------------------ http://svn.digium.com/view/asterisk-addons?view=rev&revision=913 By: Digium Subversion (svnbot) 2009-05-14 14:21:20 Repository: asterisk-addons Revision: 914 _U  branches/1.6.2/ U   branches/1.6.2/res/res_config_mysql.c ------------------------------------------------------------------------ r914 | tilghman | 2009-05-14 14:21:20 -0500 (Thu, 14 May 2009) | 14 lines Merged revisions 910 via svnmerge from https://origsvn.digium.com/svn/asterisk-addons/trunk ........  r910 | tilghman | 2009-05-14 14:16:53 -0500 (Thu, 14 May 2009) | 7 lines    Change database list to be rwlist locks, to avoid a potential deadlock between 2 readers.  (closes issue ASTERISK-14058, related to issue ASTERISK-14113)   Reported by: cristiandimache   Patches:         20090514__issue15090.diff.txt uploaded by tilghman (license 14)   Tested by: cristiandimache ........ ------------------------------------------------------------------------ http://svn.digium.com/view/asterisk-addons?view=rev&revision=914