Description:
User manual (https://dev.mysql.com/doc/refman/8.0/en/table-handles-table.html) says about which kind of locks should be put into INTERNAL_LOCK and EXTERNAL_LOCK fields of table table_handles:
----<q>----
INTERNAL_LOCK
The table lock used at the SQL level. The value is one of READ, READ WITH SHARED LOCKS, READ HIGH PRIORITY, READ NO INSERT, WRITE ALLOW WRITE, WRITE CONCURRENT INSERT, WRITE LOW PRIORITY, or WRITE. For information about these lock types, see the include/thr_lock.h source file.
EXTERNAL_LOCK
The table lock used at the storage engine level. The value is one of READ EXTERNAL or WRITE EXTERNAL.
----</q>----
However it is possible to find SQL-level lock information in the EXTERNAL_LOCK field
How to repeat:
mysql1> lock table t1 read;
Query OK, 0 rows affected (0,00 sec)
mysql2> select * from table_handles\G
*************************** 1. row ***************************
OBJECT_TYPE: TABLE
OBJECT_SCHEMA: test
OBJECT_NAME: t1
OBJECT_INSTANCE_BEGIN: 140156124286480
OWNER_THREAD_ID: 43
OWNER_EVENT_ID: 2918
INTERNAL_LOCK: NULL
EXTERNAL_LOCK: READ EXTERNAL
1 row in set (0,00 sec)
t1 is InnoDB table.
Suggested fix:
Either fix manual or code.
