MDEV-8191 - THD::set_query() takes 0.07% in OLTP RO

Moved THD::set_query() definition to sql_class.h so that it can be inlined.

Overhead change:
THD::set_query       0.07% -> out of radar

sql/sql_class.cc

@@ -5064,19 +5064,6 @@ void THD::set_command(enum enum_server_command command)
 #endif
 }
 
-/** Assign a new value to thd->query.  */
-
-void THD::set_query(const CSET_STRING &string_arg)
-{
-  mysql_mutex_lock(&LOCK_thd_data);
-  set_query_inner(string_arg);
-  mysql_mutex_unlock(&LOCK_thd_data);
-
-#ifdef HAVE_PSI_THREAD_INTERFACE
-  PSI_THREAD_CALL(set_thread_info)(query(), query_length());
-#endif
-}
-
 /** Assign a new value to thd->query and thd->query_id.  */
 
 void THD::set_query_and_id(char *query_arg, uint32 query_length_arg,

sql/sql_class.h

@@ -3704,7 +3704,16 @@ class THD :public Statement,
   {
     set_query(CSET_STRING(query_arg, query_length_arg, charset()));
   }
-  void set_query(const CSET_STRING &str); /* Mutex protected */
+  void set_query(const CSET_STRING &string_arg)
+  {
+    mysql_mutex_lock(&LOCK_thd_data);
+    set_query_inner(string_arg);
+    mysql_mutex_unlock(&LOCK_thd_data);
+
+#ifdef HAVE_PSI_THREAD_INTERFACE
+    PSI_THREAD_CALL(set_thread_info)(query(), query_length());
+#endif
+  }
   void reset_query()               /* Mutex protected */
   { set_query(CSET_STRING()); }
   void set_query_and_id(char *query_arg, uint32 query_length_arg,