MDEV-8001 - mysql_reset_thd_for_next_command() takes 0.04% in OLTP RO

Removed mysql_reset_thd_for_next_command(). Call THD::reset_for_next_command()
directly instead.

mysql_reset_thd_for_next_command() overhead dropped 0.04% -> out of radar.
THD::reset_for_next_command() overhead didn't increase.

sql/event_data_objects.cc

@@ -1337,7 +1337,7 @@ Event_job_data::execute(THD *thd, bool drop)
 
   DBUG_ENTER("Event_job_data::execute");
 
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
 
   /*
     MySQL parser currently assumes that current database is either

sql/log_event.cc

@@ -5796,7 +5796,7 @@ int Load_log_event::do_apply_event(NET* net, rpl_group_info *rgi,
   */
   lex_start(thd);
   thd->lex->local_file= local_fname;
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
 
    /*
     We test replicate_*_db rules. Note that we have already prepared
@@ -6539,7 +6539,7 @@ Gtid_log_event::do_apply_event(rpl_group_info *rgi)
   thd->variables.gtid_domain_id= this->domain_id;
   thd->variables.gtid_seq_no= this->seq_no;
   rgi->gtid_ev_flags2= flags2;
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
 
   if (opt_gtid_strict_mode && opt_bin_log && opt_log_slave_updates)
   {
@@ -7347,9 +7347,9 @@ int Xid_log_event::do_apply_event(rpl_group_info *rgi)
     mysql.gtid_slave_pos table with the GTID of the current transaction.
 
     Therefore, it acts much like a normal SQL statement, so we need to do
-    mysql_reset_thd_for_next_command() as if starting a new statement.
+    THD::reset_for_next_command() as if starting a new statement.
   */
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
   /*
     Record any GTID in the same transaction, so slave state is transactionally
     consistent.
@@ -8578,7 +8578,7 @@ int Append_block_log_event::do_apply_event(rpl_group_info *rgi)
       as the present method does not call mysql_parse().
     */
     lex_start(thd);
-    mysql_reset_thd_for_next_command(thd);
+    thd->reset_for_next_command();
     /* old copy may exist already */
     mysql_file_delete(key_file_log_event_data, fname, MYF(0));
     if ((fd= mysql_file_create(key_file_log_event_data,
@@ -9640,18 +9640,18 @@ int Rows_log_event::do_apply_event(rpl_group_info *rgi)
       Lock_tables() reads the contents of thd->lex, so they must be
       initialized.
 
-      We also call the mysql_reset_thd_for_next_command(), since this
+      We also call the THD::reset_for_next_command(), since this
       is the logical start of the next "statement". Note that this
       call might reset the value of current_stmt_binlog_format, so
       we need to do any changes to that value after this function.
     */
     delete_explain_query(thd->lex);
     lex_start(thd);
-    mysql_reset_thd_for_next_command(thd);
+    thd->reset_for_next_command();
     /*
       The current statement is just about to begin and 
       has not yet modified anything. Note, all.modified is reset
-      by mysql_reset_thd_for_next_command.
+      by THD::reset_for_next_command().
     */
     thd->transaction.stmt.modified_non_trans_table= FALSE;
     thd->transaction.stmt.m_unsafe_rollback_flags&= ~THD_TRANS::DID_WAIT;

sql/log_event_old.cc

@@ -24,7 +24,6 @@
 #include "sql_base.h"                       // close_tables_for_reopen
 #include "key.h"                            // key_copy
 #include "lock.h"                           // mysql_unlock_tables
-#include "sql_parse.h"             // mysql_reset_thd_for_next_command
 #include "rpl_rli.h"
 #include "rpl_utility.h"
 #endif
@@ -82,14 +81,14 @@ Old_rows_log_event::do_apply_event(Old_rows_log_event *ev, rpl_group_info *rgi)
       Lock_tables() reads the contents of ev_thd->lex, so they must be
       initialized.
 
-      We also call the mysql_reset_thd_for_next_command(), since this
+      We also call the THD::reset_for_next_command(), since this
       is the logical start of the next "statement". Note that this
       call might reset the value of current_stmt_binlog_format, so
       we need to do any changes to that value after this function.
     */
     delete_explain_query(thd->lex);
     lex_start(ev_thd);
-    mysql_reset_thd_for_next_command(ev_thd);
+    ev_thd->reset_for_next_command();
 
     /*
       This is a row injection, so we flag the "statement" as

sql/rpl_gtid.cc

@@ -533,7 +533,7 @@ rpl_slave_state::record_gtid(THD *thd, const rpl_gtid *gtid, uint64 sub_id,
   }
 
   if (!in_statement)
-    mysql_reset_thd_for_next_command(thd);
+    thd->reset_for_next_command();
 
   DBUG_EXECUTE_IF("gtid_inject_record_gtid",
                   {

sql/rpl_rli.cc

@@ -1485,7 +1485,7 @@ rpl_load_gtid_slave_state(THD *thd)
     goto end;
   array_inited= true;
 
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
 
   tlist.init_one_table(STRING_WITH_LEN("mysql"),
                        rpl_gtid_slave_state_table_name.str,

sql/sql_class.h

@@ -2685,7 +2685,7 @@ class THD :public Statement,
     can not continue. In particular, disables activation of
     CONTINUE or EXIT handlers of stored routines.
     Reset in the end of processing of the current user request, in
-    @see mysql_reset_thd_for_next_command().
+    @see THD::reset_for_next_command().
   */
   bool is_fatal_error;
   /**

sql/sql_parse.cc

@@ -1593,7 +1593,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       break;
     }
     packet= arg_end + 1;
-    mysql_reset_thd_for_next_command(thd);
+    thd->reset_for_next_command();
     lex_start(thd);
     /* Must be before we init the table list. */
     if (lower_case_table_names)
@@ -6723,15 +6723,8 @@ bool my_yyoverflow(short **yyss, YYSTYPE **yyvs, ulong *yystacksize)
   (prepared or conventional).  It is not called by substatements of
   routines.
 
-  @todo Remove mysql_reset_thd_for_next_command and only use the
-  member function.
-
   @todo Call it after we use THD for queries, not before.
 */
-void mysql_reset_thd_for_next_command(THD *thd)
-{
-  thd->reset_for_next_command();
-}
 
 void THD::reset_for_next_command()
 {
@@ -7005,7 +6998,7 @@ static void wsrep_mysql_parse(THD *thd, char *rawbuf, uint length,
       if (thd->wsrep_conflict_state == ABORTED ||
           thd->wsrep_conflict_state == CERT_FAILURE)
       {
-        mysql_reset_thd_for_next_command(thd);
+        thd->reset_for_next_command();
         thd->killed= NOT_KILLED;
         if (is_autocommit                           &&
             thd->lex->sql_command != SQLCOM_SELECT  &&
@@ -7101,13 +7094,13 @@ void mysql_parse(THD *thd, char *rawbuf, uint length,
     of (among others) lex->safe_to_cache_query and thd->server_status,
     which are reset respectively in
     - lex_start()
-    - mysql_reset_thd_for_next_command()
+    - THD::reset_for_next_command()
     So, initializing the lexical analyser *before* using the query cache
     is required for the cache to work properly.
     FIXME: cleanup the dependencies in the code to simplify this.
   */
   lex_start(thd);
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
 
   if (query_cache_send_result_to_client(thd, rawbuf, length) <= 0)
   {
@@ -7221,7 +7214,7 @@ bool mysql_test_parse_for_slave(THD *thd, char *rawbuf, uint length)
   if (!(error= parser_state.init(thd, rawbuf, length)))
   {
     lex_start(thd);
-    mysql_reset_thd_for_next_command(thd);
+    thd->reset_for_next_command();
 
     if (!parse_sql(thd, & parser_state, NULL, true) &&
         all_tables_not_ok(thd, lex->select_lex.table_list.first))

sql/sql_parse.h

@@ -88,7 +88,6 @@ bool alloc_query(THD *thd, const char *packet, uint packet_length);
 void mysql_init_select(LEX *lex);
 void mysql_parse(THD *thd, char *rawbuf, uint length,
                  Parser_state *parser_state);
-void mysql_reset_thd_for_next_command(THD *thd);
 bool mysql_new_select(LEX *lex, bool move_down);
 void create_select_for_variable(const char *var_name);
 void create_table_set_open_action_and_adjust_tables(LEX *lex);

sql/sql_prepare.cc

@@ -2309,7 +2309,7 @@ void mysqld_stmt_prepare(THD *thd, const char *packet, uint packet_length)
   DBUG_PRINT("prep_query", ("%s", packet));
 
   /* First of all clear possible warnings from the previous command */
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
 
   if (! (stmt= new Prepared_statement(thd)))
     goto end;           /* out of memory: error is set in Sql_alloc */
@@ -2700,7 +2700,7 @@ void mysqld_stmt_execute(THD *thd, char *packet_arg, uint packet_length)
   packet+= 9;                               /* stmt_id + 5 bytes of flags */
 
   /* First of all clear possible warnings from the previous command */
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
 
   if (!(stmt= find_prepared_statement(thd, stmt_id)))
   {
@@ -2799,7 +2799,7 @@ void mysqld_stmt_fetch(THD *thd, char *packet, uint packet_length)
   DBUG_ENTER("mysqld_stmt_fetch");
 
   /* First of all clear possible warnings from the previous command */
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
 
   status_var_increment(thd->status_var.com_stmt_fetch);
   if (!(stmt= find_prepared_statement(thd, stmt_id)))
@@ -2859,7 +2859,7 @@ void mysqld_stmt_reset(THD *thd, char *packet)
   DBUG_ENTER("mysqld_stmt_reset");
 
   /* First of all clear possible warnings from the previous command */
-  mysql_reset_thd_for_next_command(thd);
+  thd->reset_for_next_command();
 
   status_var_increment(thd->status_var.com_stmt_reset);
   if (!(stmt= find_prepared_statement(thd, stmt_id)))

sql/wsrep_thd.cc

@@ -192,7 +192,7 @@ void wsrep_replay_transaction(THD *thd)
       thd->wsrep_conflict_state= REPLAYING;
       mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
 
-      mysql_reset_thd_for_next_command(thd);
+      thd->reset_for_next_command();
       thd->killed= NOT_KILLED;
       close_thread_tables(thd);
       if (thd->locked_tables_mode && thd->lock)