Commit 3db332ca authored by unknown's avatar unknown
Browse files

row0mysql.c, row0mysql.h, ha_innodb.cc: 

  Inside LOCK TABLES, use either LOCK_S or LOCK_X in locking reads; an improvent over the previous patch


sql/ha_innodb.cc:
  Inside LOCK TABLES, use either LOCK_S or LOCK_X in locking reads; an improvent over the previous patch
innobase/include/row0mysql.h:
  Inside LOCK TABLES, use either LOCK_S or LOCK_X in locking reads; an improvent over the previous patch
innobase/row/row0mysql.c:
  Inside LOCK TABLES, use either LOCK_S or LOCK_X in locking reads; an improvent over the previous patch
parent 80c66247

innobase/include/row0mysql.h

+3 −0
Original line number Diff line number Diff line
@@ -507,6 +507,9 @@ struct row_prebuilt_struct { 
	dtuple_t*	clust_ref;	/* prebuilt dtuple used in

					sel/upd/del */

	ulint		select_lock_type;/* LOCK_NONE, LOCK_S, or LOCK_X */

	ulint		stored_select_lock_type;/* inside LOCK TABLES, either

					LOCK_S or LOCK_X depending on the lock

					type */

	ulint		mysql_row_len;	/* length in bytes of a row in the

					MySQL format */

	ulint		n_rows_fetched;	/* number of rows fetched after

innobase/row/row0mysql.c

+1 −0
Original line number Diff line number Diff line
@@ -380,6 +380,7 @@ row_create_prebuilt( 
  	prebuilt->clust_pcur = btr_pcur_create_for_mysql();



	prebuilt->select_lock_type = LOCK_NONE;

	prebuilt->stored_select_lock_type = 99999999;



	prebuilt->sel_graph = NULL;

sql/ha_innodb.cc

+32 −10
Original line number Diff line number Diff line
@@ -4505,16 +4505,38 @@ ha_innobase::start_stmt( 
	  

	        prebuilt->select_lock_type = LOCK_X;

	} else {

		/* When we first come here after LOCK TABLES,

		select_lock_type is set to LOCK_S or LOCK_X. Store the value

		in case we run also consistent reads and need to restore the

		value later. */



		if (prebuilt->select_lock_type != LOCK_NONE) {

			prebuilt->stored_select_lock_type =

					prebuilt->select_lock_type;

		}



		if (prebuilt->stored_select_lock_type != LOCK_S

		    && prebuilt->stored_select_lock_type != LOCK_X) {

			fprintf(stderr,

"InnoDB: Error: select_lock_type is %lu inside ::start_stmt()!\n",

			prebuilt->stored_select_lock_type);



			ut_error;

		}



		if (thd->lex.sql_command == SQLCOM_SELECT

					&& thd->lex.lock_option == TL_READ) {

	

			/* For other than temporary tables, we obtain

		no lock for consistent read (plain SELECT), and

		an exclusive lock for SELECT ... FOR UPDATE or

		SELECT ... LOCK IN SHARE MODE. */

			no lock for consistent read (plain SELECT) */



			prebuilt->select_lock_type = LOCK_NONE;

		} else {

			/* Not a consistent read: restore the

			select_lock_type value */

			prebuilt->select_lock_type =

			thd->lex.sql_command == SQLCOM_SELECT

			&& thd->lex.lock_option == TL_READ

			? LOCK_NONE

			: LOCK_X;

				prebuilt->stored_select_lock_type;

		}

	}

	

	/* Set the MySQL flag to mark that there is an active transaction */