Drop table if exists t;

CREATE TABLE `t` (

`id` int(11) NOT NULL AUTO_INCREMENT,

PRIMARY KEY (`id`)

) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1 ;

set autocommit = 0;

insert into t values(1);

select sleep(10) from t;

set lock_wait_timeout = 1;flush tables with read lock;

MariaDB [(none)]> select *                

    -> from information_schema.METADATA_LOCK_INFO;

Select thread_id,lock_mode,lock_type

 from information_schema.METADATA_LOCK_INFO;

+-----------+------------+------------------+

| thread_id | lock_mode  | lock_type        |

+-----------+------------+------------------+

|         7 | MDL_SHARED | Global read lock |

|         7 | MDL_SHARED | Commit lock      |

|         6 | MDL_SHARED_WRITE | Table metadata lock      |

+-----------+------------+------------------+