attempt to install a plugin twice
Server crashes when [UN]INSTALL PLUGIN fails (returns an
error) and general log is disabled and there are audit
plugins interested in MYSQL_AUDIT_GENERAL_CLASS.
When audit event is triggered, audit subsystem acquires interested
plugins by walking through plugin list. Evidently plugin list
iterator protects plugin list by acquiring LOCK_plugin, see
plugin_foreach_with_mask().
On the other hand [UN]INSTALL PLUGIN is acquiring LOCK_plugin
rather for a long time.
When audit event is triggered during [UN]INSTALL PLUGIN, plugin
list iterator acquires the same lock (within the same thread)
second time.
Repeatable only with general_log disabled, because general_log
triggers MYSQL_AUDIT_GENERAL_LOG event, which acquires audit
plugins before [UN]INSTALL PLUGIN acquired LOCK_plugin.
With this fix we pre-acquire audit plugins for events that
may potentially occur during [UN]INSTALL PLUGIN.
This hack should be removed when LOCK_plugin is fixed so it
protects only what it supposed to protect.
No test case for this fix - we do not have facility to test
audit plugins yet.
This patch:
- Moves all definitions from the mysql_priv.h file into
header files for the component where the variable is
defined
- Creates header files if the component lacks one
- Eliminates all include directives from mysql_priv.h
- Eliminates all circular include cycles
- Rename time.cc to sql_time.cc
- Rename mysql_priv.h to sql_priv.h
WL#3771
"Audit Plugin Interface"
Implement new plug-in type - AUDIT
New plug-in: audit_null
simply increments counter for how many times it was called.
