1berry/MariaDB-server
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Bug#20788853 MUTEX ISSUE IN SQL/SQL_SHOW.CC RESULTING IN SIG6. SOURCE LIKELY

Browse Source 
FILL_VARIABLES

Prevent mutexes used in SHOW VARIABLES from being locked twice.
This commit is contained in:
Marc Alff 2015-04-08 07:01:39 +02:00
parent 45b51146a9
commit 7285b4c495
3 changed files with 12 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
sql/sql_class.cc
View File

@ -802,6 +802,7 @@ THD::THD()
rli_fake(0), rli_slave(NULL), rli_fake(0), rli_slave(NULL),
user_time(0), in_sub_stmt(0), user_time(0), in_sub_stmt(0),
fill_status_recursion_level(0), fill_status_recursion_level(0),
fill_variables_recursion_level(0),
binlog_unsafe_warning_flags(0), binlog_unsafe_warning_flags(0),
binlog_table_maps(0), binlog_table_maps(0),
table_map_for_update(0), table_map_for_update(0),

1
sql/sql_class.h
View File

@ -1603,6 +1603,7 @@ public:
decremented each time before it returns from the function. decremented each time before it returns from the function.
*/ */
uint fill_status_recursion_level; uint fill_status_recursion_level;
uint fill_variables_recursion_level;
/* container for handler's private per-connection data */ /* container for handler's private per-connection data */
Ha_data ha_data[MAX_HA]; Ha_data ha_data[MAX_HA];

12
sql/sql_show.cc
View File

@ -6317,7 +6317,11 @@ int fill_variables(THD *thd, TABLE_LIST *tables, COND *cond)
Lock LOCK_plugin_delete to avoid deletion of any plugins while creating Lock LOCK_plugin_delete to avoid deletion of any plugins while creating
SHOW_VAR array and hold it until all variables are stored in the table. SHOW_VAR array and hold it until all variables are stored in the table.
*/ */
mysql_mutex_lock(&LOCK_plugin_delete); if (thd->fill_variables_recursion_level++ == 0)
{
mysql_mutex_lock(&LOCK_plugin_delete);
}
// Lock LOCK_system_variables_hash to prepare SHOW_VARs array. // Lock LOCK_system_variables_hash to prepare SHOW_VARs array.
mysql_rwlock_rdlock(&LOCK_system_variables_hash); mysql_rwlock_rdlock(&LOCK_system_variables_hash);
DEBUG_SYNC(thd, "acquired_LOCK_system_variables_hash"); DEBUG_SYNC(thd, "acquired_LOCK_system_variables_hash");
@ -6327,7 +6331,11 @@ int fill_variables(THD *thd, TABLE_LIST *tables, COND *cond)
res= show_status_array(thd, wild, sys_var_array, option_type, NULL, "", res= show_status_array(thd, wild, sys_var_array, option_type, NULL, "",
tables->table, upper_case_names, cond); tables->table, upper_case_names, cond);
mysql_mutex_unlock(&LOCK_plugin_delete); if (thd->fill_variables_recursion_level-- == 1)
{
mysql_mutex_unlock(&LOCK_plugin_delete);
}
DBUG_RETURN(res); DBUG_RETURN(res);
} }