MDEV-12179: Per-engine mysql.gtid_slave_pos tablesbb-10.3-mdev12179

Merge to 10.3
- changed a few LEX_STRING to LEX_CSTRING

1 files changed, 30 insertions, 0 deletions

diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index 92b9c94e84c..c73229a2ee0 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -941,6 +941,10 @@ SHOW_COMP_OPTION plugin_status(const char *name, size_t len, int type)
 }
 
 
+/*
+  If LEX is passed non-NULL, an automatic unlock of the plugin will happen
+  in the LEX destructor.
+*/
 static plugin_ref intern_plugin_lock(LEX *lex, plugin_ref rc)
 {
   st_plugin_int *pi= plugin_ref_to_int(rc);
@@ -984,6 +988,16 @@ static plugin_ref intern_plugin_lock(LEX *lex, plugin_ref rc)
 }
 
 
+/*
+  Notes on lifetime:
+
+  If THD is passed as non-NULL (and with a non-NULL thd->lex), an entry is made
+  in the thd->lex which will cause an automatic unlock of the plugin in the LEX
+  destructor. In this case, no manual unlock must be done.
+
+  Otherwise, when passing a NULL THD, the caller must arrange that plugin
+  unlock happens later.
+*/
 plugin_ref plugin_lock(THD *thd, plugin_ref ptr)
 {
   LEX *lex= thd ? thd->lex : 0;
@@ -1020,6 +1034,16 @@ plugin_ref plugin_lock(THD *thd, plugin_ref ptr)
 }
 
 
+/*
+  Notes on lifetime:
+
+  If THD is passed as non-NULL (and with a non-NULL thd->lex), an entry is made
+  in the thd->lex which will cause an automatic unlock of the plugin in the LEX
+  destructor. In this case, no manual unlock must be done.
+
+  Otherwise, when passing a NULL THD, the caller must arrange that plugin
+  unlock happens later.
+*/
 plugin_ref plugin_lock_by_name(THD *thd, const LEX_CSTRING *name, int type)
 {
   LEX *lex= thd ? thd->lex : 0;
@@ -1935,6 +1959,12 @@ void plugin_shutdown(void)
 
   if (initialized)
   {
+    if (opt_gtid_pos_auto_plugins)
+    {
+      free_engine_list(opt_gtid_pos_auto_plugins);
+      opt_gtid_pos_auto_plugins= NULL;
+    }
+
     mysql_mutex_lock(&LOCK_plugin);
 
     reap_needed= true;