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

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=17950 
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Reported By:                schmidts
Assigned To:                
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Project:                    Asterisk
Issue ID:                   17950
Category:                   Channels/chan_sip/Subscriptions
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     new
Asterisk Version:           SVN 
JIRA:                        
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:              2010-09-07 12:56 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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 (0126680) schmidts (reporter) - 2010-09-07 12:56
 https://issues.asterisk.org/view.php?id=17950#c126680 
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it is an issue, but after i have put the review request into the
reviewboard i realise there might be no need to let this issue stay open. 

Issue History 
Date Modified    Username       Field                    Change               
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2010-09-07 12:56 schmidts       Note Added: 0126680                          
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