[asterisk-bugs] [Asterisk 0014738]: Address device state performance issues in 1.6.1

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
====================================================================== 
http://bugs.digium.com/view.php?id=14738 
====================================================================== 
Reported By:                russell
Assigned To:                russell
====================================================================== 
Project:                    Asterisk
Issue ID:                   14738
Category:                   Core/General
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     closed
Target Version:             1.6.1.0
Asterisk Version:           1.6.1.0-rc3 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
Resolution:                 fixed
Fixed in Version:           
====================================================================== 
Date Submitted:             2009-03-24 13:39 CDT
Last Modified:              2009-03-25 17:02 CDT
====================================================================== 
Summary:                    Address device state performance issues in 1.6.1
Description: 
http://reviewboard.digium.com/r/205/
====================================================================== 

---------------------------------------------------------------------- 
 (0102192) svnbot (reporter) - 2009-03-25 17:02
 http://bugs.digium.com/view.php?id=14738#c102192 
---------------------------------------------------------------------- 
Repository: asterisk
Revision: 184342

_U  branches/1.6.1/
U   branches/1.6.1/apps/app_voicemail.c
U   branches/1.6.1/channels/chan_dahdi.c
U   branches/1.6.1/channels/chan_iax2.c
U   branches/1.6.1/channels/chan_mgcp.c
U   branches/1.6.1/channels/chan_sip.c
U   branches/1.6.1/channels/chan_skinny.c
U   branches/1.6.1/channels/chan_unistim.c
U   branches/1.6.1/include/asterisk/_private.h
U   branches/1.6.1/include/asterisk/devicestate.h
U   branches/1.6.1/include/asterisk/event.h
U   branches/1.6.1/include/asterisk/strings.h
U   branches/1.6.1/main/asterisk.c
U   branches/1.6.1/main/devicestate.c
U   branches/1.6.1/main/event.c
U   branches/1.6.1/res/ais/evt.c

------------------------------------------------------------------------
r184342 | russell | 2009-03-25 17:02:22 -0500 (Wed, 25 Mar 2009) | 43
lines

Merged revisions 184339 via svnmerge from 
https://origsvn.digium.com/svn/asterisk/trunk

........
r184339 | russell | 2009-03-25 16:57:19 -0500 (Wed, 25 Mar 2009) | 35
lines

Improve performance of the ast_event cache functionality.

This code comes from svn/asterisk/team/russell/event_performance/.

Here is a summary of the changes that have been made, in order of both
invasiveness and performance impact, from smallest to largest.

1) Asterisk 1.6.1 introduces some additional logic to be able to handle
   distributed device state.  This functionality comes at a cost.
   One relatively minor change in this patch is that the extra processing
   required for distributed device state is now completely bypassed if
   it's not needed.

2) One of the things that I noticed when profiling this code was that a
   _lot_ of time was spent doing string comparisons.  I changed the way
   strings are represented in an event to include a hash value at the
front.
   So, before doing a string comparison, we do an integer comparison on
the
   hash.

3) Finally, the code that handles the event cache has been re-written.
   I tried to do this in a such a way that it had minimal impact on the
API.
   I did have to change one API call, though -
ast_event_queue_and_cache().
   However, the way it works now is nicer, IMO.  Each type of event that
   can be cached (MWI, device state) has its own hash table and rules for
   hashing and comparing objects.  This by far made the biggest impact on
   performance.

For additional details regarding this code and how it was tested, please
see the
review request.

(closes issue http://bugs.digium.com/view.php?id=14738)
Reported by: russell

Review: http://reviewboard.digium.com/r/205/

........

------------------------------------------------------------------------

http://svn.digium.com/view/asterisk?view=rev&revision=184342 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2009-03-25 17:02 svnbot         Checkin                                      
2009-03-25 17:02 svnbot         Note Added: 0102192                          
======================================================================