mariadb/mysql-test/suite/innodb/t/gap_locks.test
Marko Mäkelä 33d41167c5 MDEV-24224 Gap lock on delete in 10.5 using READ COMMITTED
When MDEV-19544 (commit 1a6f470464)
simplified the initialization of the local variable
set_also_gap_locks, an inadvertent change was included.
Essentially, all code branches that are executed when
set_also_gap_locks hold must also ensure that
trx->isolation_level > TRX_ISO_READ_COMMITTED holds.
This was being violated in a few code paths.

It turns out that there is an even simpler fix: Remove the test
of thd_is_select() completely. In that way, the first part of
UPDATE or DELETE should work exactly like SELECT...FOR UPDATE.

thd_is_select(): Remove.
2020-11-18 10:27:18 +02:00

29 lines
765 B
Text

--source include/have_innodb.inc
CREATE TABLE t1(a INT PRIMARY KEY, b VARCHAR(40), c INT, INDEX(b,c))
ENGINE=InnoDB;
INSERT INTO t1 VALUES (1,'1',1),(2,'2',1);
SET @save_locks= @@GLOBAL.innodb_status_output_locks;
SET GLOBAL INNODB_STATUS_OUTPUT_LOCKS = 'ON';
let $isolation= 4;
while ($isolation) {
let $tx_isolation= `SELECT CASE $isolation
WHEN 1 THEN 'READ UNCOMMITTED'
WHEN 2 THEN 'READ COMMITTED'
WHEN 3 THEN 'REPEATABLE READ'
ELSE 'SERIALIZABLE' END`;
eval SET TRANSACTION ISOLATION LEVEL $tx_isolation;
BEGIN;
DELETE FROM t1 WHERE b='2' AND c=2;
--replace_regex /.*(\d+ lock struct...), heap size \d+(, \d+ row lock...).*/\1\2/
SHOW ENGINE INNODB STATUS;
ROLLBACK;
dec $isolation;
}
SET GLOBAL INNODB_STATUS_OUTPUT_LOCKS = @save_locks;
DROP TABLE t1;