[asterisk-bugs] [Asterisk 0017950]: iterate through all ao2_sip dialogs on every subscribe is slow, and not needed

[Asterisk Bug Tracker]

The following issue has been ASSIGNED. 
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https://issues.asterisk.org/view.php?id=17950 
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Reported By:                schmidts
Assigned To:                russell
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Project:                    Asterisk
Issue ID:                   17950
Category:                   Channels/chan_sip/Subscriptions
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     acknowledged
Target Version:             1.6.2.15
Asterisk Version:           SVN 
JIRA:                       SWP-2173 
Regression:                 No 
Reviewboard Link:           https://reviewboard.asterisk.org/r/901/ 
SVN Branch (only for SVN checkouts, not tarball releases): 1.6.2 
SVN Revision (number only!): 284848 
Request Review:              
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Date Submitted:             2010-09-03 07:10 CDT
Last Modified:              2010-09-17 09:30 CDT
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Summary:                    iterate through all ao2_sip dialogs on every
subscribe is slow, and not needed
Description: 
on my time compares i have seen that the while loop in
handle_request_subscribe tooks even 2 ms on the first subscribe and this
counts up to at least 20ms with more than 1000 subscribes.
I´ve talked with Olle johansson and Klaus Darillion about this problem
and both said its not correct handling of a subscribe without a tag to
search for old subscribes from this peer for the exten and context. This
will cause old subscribes from the same peer to be present until the
expires and also the notifys will be send to this old subscribe too.

on a heave loaded system (> 1000 sip dialogs) this will make subscribe
handling even 20 times faster.
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Issue History 
Date Modified    Username       Field                    Change               
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2010-09-17 09:30 lmadsen        Assigned To               => russell         
2010-09-17 09:30 lmadsen        Target Version            => 1.6.2.15        
2010-09-17 09:30 lmadsen        Description Updated                          
2010-09-17 09:30 lmadsen        Additional Information Updated                  
 
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