[asterisk-dev] [Code Review] 4141: Enable REF_DEBUG for ast_module_ref / ast_module_unref

[Corey Farrell]

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This is an automatically generated e-mail. To reply, visit:
https://reviewboard.asterisk.org/r/4141/
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(Updated Feb. 5, 2015, 3:36 a.m.)


Review request for Asterisk Developers.


Changes
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* Make all 3 functions always accept the REF_DEBUG parameters.  They are not called enough to be worth the optimization by removing the unused parameters.
* Updated patch to show actual code for 11.  13/trunk are different in bridge_builtin_features.c
* Switched list iteration to normal (non _SAFE) as no elements are added/removed.
* Address findings


Bugs: ASTERISK-24479
    https://issues.asterisk.org/jira/browse/ASTERISK-24479


Repository: Asterisk


Description (updated)
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This change includes an ABI change with compatibility stubs for 11 and 13.  The compatibility stubs will not be included in trunk.  The point of this change is to have each module create an AO2 object on load, and hopefully destroy it on unload.  This allows module reference count errors to be debugged through REF_DEBUG.

When REF_DEBUG is enabled:
* adds an empty ao2 object to 'struct ast_module'
* Allocate ao2 when the module is loaded
* Perform an ao2_ref in each place where mod->usecount is manipulated.
* ao2_cleanup on module unload.


The passthrough of file, line and func is needed for the REF_DEBUG to be of any use, so without the ABI changes this is not useful.

The change to bridge_builtin_features.c ensures that the module cannot be manually unloaded, but is able to be unloaded during ast_module_shutdown.  Note ast_module_shutdown only happens during clean shutdown and does not actually run dlclose so this is safe.


Diffs (updated)
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  /branches/11/main/loader.c 429406 
  /branches/11/include/asterisk/module.h 429406 
  /branches/11/bridges/bridge_builtin_features.c 429406 

Diff: https://reviewboard.asterisk.org/r/4141/diff/


Testing
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Using tests/manager/originate with REF_DEBUG enabled.  When the change to bridge_builtin_features.c is omitted the test fails due to that one reference leak.


Thanks,

Corey Farrell

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