[asterisk-bugs] [Asterisk 0015189]: [patch] #exec script can't access manager on first asterisk load

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=15189 
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Reported By:                p_lindheimer
Assigned To:                seanbright
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Project:                    Asterisk
Issue ID:                   15189
Category:                   Core/PBX
Reproducibility:            always
Severity:                   block
Priority:                   normal
Status:                     closed
Target Version:             1.4.26
Asterisk Version:           SVN 
Regression:                 Yes 
SVN Branch (only for SVN checkouts, not tarball releases):  1.4  
SVN Revision (number only!): 196616 
Request Review:              
Resolution:                 fixed
Fixed in Version:           
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Date Submitted:             2009-05-24 12:32 CDT
Last Modified:              2009-06-04 09:17 CDT
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Summary:                    [patch] #exec script can't access manager on first
asterisk load
Description: 
In earlier versions of Asterisk (1.4.21.1 tested, also 1.2.x I believe), a
'#exec' directive in extensions.conf can run a script that can then access
the manager which is required to get to ASTDB to obtain information to
generate dialplan.

A fix to bug https://issues.asterisk.org/view.php?id=13778 (revision 151905) has
broken this.
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Relationships       ID      Summary
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child of            0013778 asterisk blocked at startup between mai...
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 (0105974) svnbot (reporter) - 2009-06-04 09:17
 https://issues.asterisk.org/view.php?id=15189#c105974 
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Repository: asterisk
Revision: 199022

U   branches/1.4/include/asterisk.h
U   branches/1.4/main/asterisk.c
U   branches/1.4/main/loader.c

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r199022 | seanbright | 2009-06-04 09:14:57 -0500 (Thu, 04 Jun 2009) | 40
lines

Safely handle AMI connections/reload requests that occur during startup.

During asterisk startup, a lock on the list of modules is obtained by the
primary thread while each module is initialized.  Issue 13778 pointed out
a
problem with this approach, however.  Because the AMI is loaded before
other
modules, it is possible for a module reload to be issued by a connected
client
(via Action: Command), causing a deadlock.

The resolution for 13778 was to move initialization of the manager to
happen
after the other modules had already been lodaded.  While this fixed this
particular issue, it caused a problem for users (like FreePBX) who call
AMI
scripts via an #exec in a configuration file (See issue 15189).

The solution I have come up with is to defer any reload requests that come
in
until after the server is fully booted.  When a call comes in to
ast_module_reload (from wherever) before we are fully booted, the request
is
added to a queue of pending requests.  Once we are done booting up, we
then
execute these deferred requests in turn.

Note that I have tried to make this a bit more intelligent in that it will
not
queue up more than 1 request for the same module to be reloaded, and if a
general reload request comes in ('module reload') the queue is flushed and
we
only issue a single deferred reload for the entire system.

As for how this will impact existing installations - Before 13778, a
reload
issued before module initialization was completed would result in a
deadlock.
After 13778, you simply couldn't connect to the manager during startup
(which
causes problems with #exec-that-calls-AMI configuration files).  I believe
this
is a good general purpose solution that won't negatively impact existing
installations.

(closes issue https://issues.asterisk.org/view.php?id=15189)
(closes issue https://issues.asterisk.org/view.php?id=13778)
Reported by: p_lindheimer
Patches:
      06032009_15189_deferred_reloads.diff uploaded by seanbright (license
71)
Tested by: p_lindheimer, seanbright

Review: https://reviewboard.asterisk.org/r/272/

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http://svn.digium.com/view/asterisk?view=rev&revision=199022 

Issue History 
Date Modified    Username       Field                    Change               
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2009-06-04 09:17 svnbot         Checkin                                      
2009-06-04 09:17 svnbot         Note Added: 0105974                          
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