mariadb/mysql-test/suite/innodb/t/avoid_deadlock_with_blocked.test

--source include/have_innodb.inc
--source include/have_debug.inc
--source include/have_debug_sync.inc
--source include/count_sessions.inc

--disable_query_log
call mtr.add_suppression("InnoDB: Transaction was aborted due to ");
--enable_query_log

connect stop_purge,localhost,root;
START TRANSACTION WITH CONSISTENT SNAPSHOT;

--connect (con1,localhost,root,,)
--connect (con2,localhost,root,,)
--connect (con3,localhost,root,,)

--connection default
CREATE TABLE t1 (id INT PRIMARY KEY) ENGINE=InnoDB STATS_PERSISTENT=0;
INSERT INTO t1 (id) VALUES (1);

--echo # Simplest scenario:
--echo # <con1, S, granted>,
--echo # <con1, S, granted>, <con2, X, waiting for con1>,
--echo # Before MDEV-34877:
--echo # <con1, S, granted>, <con2, X, waiting for con1>, <con1, X, waiting for con1>
--echo # After MDEV-34877:
--echo # <con1, S, granted>, <con1, X, granted>, <con2, X, waiting for con1>
--echo # Expected: instead of deadlocking, the con1's request should ignore con2's

--connection con1
  BEGIN;
  SELECT * FROM t1 LOCK IN SHARE MODE;

--connection con2
  BEGIN;
  SET DEBUG_SYNC = 'lock_wait_before_suspend SIGNAL con2_will_wait';
  --send SELECT * FROM t1 FOR UPDATE

--connection con1
  SET DEBUG_SYNC = 'now WAIT_FOR con2_will_wait';
  SELECT * FROM t1 FOR UPDATE;
  COMMIT;

--connection con2
  --reap
  COMMIT;

--echo # The scenario when we bypass X<-S pair:
--echo # <con1, S, granted>,
--echo # <con1, S, granted>, <con2, X, waiting for con1>,
--echo # <con1, S, granted>, <con2, X, waiting for con1>, <con3, S, waiting for con2>
--echo # <con1, S, granted>, <con1, X, granted>, <con2, X, waiting for con1>, <con3, S, waiting for con2>

--connection con1
  BEGIN;
  SELECT * FROM t1 LOCK IN SHARE MODE;

--connection con2
  BEGIN;
  SET DEBUG_SYNC = 'lock_wait_before_suspend SIGNAL con2_will_wait';
  --send SELECT * FROM t1 FOR UPDATE

--connection con3
  SET DEBUG_SYNC = 'now WAIT_FOR con2_will_wait';
  BEGIN;
  SET DEBUG_SYNC = 'lock_wait_before_suspend SIGNAL con3_will_wait';
  --send SELECT * FROM t1 LOCK IN SHARE MODE;

--connection con1
  SET DEBUG_SYNC = 'now WAIT_FOR con3_will_wait';
  SELECT * FROM t1 FOR UPDATE;
  COMMIT;

--connection con2
  --reap
  COMMIT;

--connection con3
  --reap
  COMMIT;

#
--echo # A variant of the above scenario:
--echo # <con1, X REC_NOT_GAP, granted>,
--echo # <con1, X REC_NOT_GAP, granted>, <con2, S, waiting for con1>,
--echo # <con1, X REC_NOT_GAP, granted>, <con2, S, waiting for con1>, <con1, INSERT INTENTION, waiting for con1>
--echo # Expected: a deadlock, as INSERT INTENTION should not overtake locks on gap, to not slice them
--connection con1
  BEGIN;
  SELECT * FROM t1 WHERE id=1 FOR UPDATE;

--connection con2
  BEGIN;
  SET DEBUG_SYNC = 'lock_wait_start SIGNAL con2_will_wait';
  --send SELECT * FROM t1 LOCK IN SHARE MODE

--connection con1
  SET DEBUG_SYNC = 'now WAIT_FOR con2_will_wait';
  INSERT INTO t1 VALUES (0);
  ROLLBACK;

--connection con2
  --error ER_LOCK_DEADLOCK
  --reap
  COMMIT;

--echo # More complicated scenario:
--echo # <con1, S, granted>,
--echo # <con1, S, granted>, <con2, S REC_NOT_GAP, granted>,
--echo # <con1, S, granted>, <con2, S REC_NOT_GAP, granted>, <con3, X, waiting for con1>
--echo # <con1, S, granted>, <con2, S REC_NOT_GAP, granted>, <con3, X, waiting for con1>, <con1, INSERT_INTENTION, waiting for con3>
--echo # <con1, S, granted>, <con3, X, waiting for con1>, <con1, INSERT_INTENTION, waiting for con3>
--echo # Expected: a deadlock, as INSERT INTENTION should not overtake locks on gap, to not slice them

--connection con1
  BEGIN;
  SELECT * FROM t1 LOCK IN SHARE MODE;

--connection con2
  BEGIN;
  SELECT * FROM t1 WHERE id=1 LOCK IN SHARE MODE;

--connection con3
  SET DEBUG_SYNC = 'lock_wait_before_suspend SIGNAL con3_will_wait';
  --send SELECT * FROM t1 FOR UPDATE

--connection con1
  SET DEBUG_SYNC = 'now WAIT_FOR con3_will_wait';
  SET DEBUG_SYNC = 'lock_wait_start SIGNAL con1_will_wait';
  --send INSERT INTO t1 VALUES (0)

--connection con2
  SET DEBUG_SYNC = 'now WAIT_FOR con1_will_wait';
  COMMIT;

--connection con1
  --reap
  ROLLBACK;

--connection con3
  --error ER_LOCK_DEADLOCK
  --reap

--echo # More complicated scenario.
--echo # <con1, S, granted>,
--echo # <con1, S, granted>, <con2, S REC_NOT_GAP, granted>,
--echo # <con1, S, granted>, <con2, S REC_NOT_GAP, granted>, <con3, X, waiting for con1>
--echo # <con1, S, granted>, <con2, S REC_NOT_GAP, granted>, <con3, X, waiting for con1>, <con1, X REC_NOT_GAP, waiting for con2>
--echo # Before MDEV-34877:
--echo # <con1, S, granted>, <con3, X, waiting for con1>, <con1, X REC_NOT_GAP, waiting for con3>
--echo # After MDEV-34877:
--echo # <con1, S, granted>, <con1, X REC_NOT_GAP, granted>, <con3, X, waiting for con1>


--connection con1
  BEGIN;
  SELECT * FROM t1 LOCK IN SHARE MODE;

--connection con2
  BEGIN;
  SELECT * FROM t1 WHERE id=1 LOCK IN SHARE MODE;

--connection default

--connection con3
  SET DEBUG_SYNC = 'lock_wait_before_suspend SIGNAL con3_will_wait';
  --send SELECT * FROM t1 FOR UPDATE

--connection con1
  SET DEBUG_SYNC = 'now WAIT_FOR con3_will_wait';
  SET DEBUG_SYNC = 'lock_wait_before_suspend SIGNAL con1_will_wait';
  --send SELECT * FROM t1 WHERE id=1 FOR UPDATE

--connection con2
  SET DEBUG_SYNC = 'now WAIT_FOR con1_will_wait';
  COMMIT;

--connection con1
  --reap
  COMMIT;

--connection con3
  --reap
  COMMIT;

--echo # A scenario, where con1 has to bypass two transactions:
--echo # <con1, S, granted>
--echo # <con1, S, granted> <con2, X, waiting>
--echo # <con1, S, granted> <con2, X, waiting> <con3, X, waiting>
--echo # Before MDEV-34877:
--echo # <con1, S, granted> <con2, X, waiting> <con3, X, waiting> <con1, X REC_NOT_GAP, waiting for con2>
--echo # After MDEV-34877:
--echo # <con1, S, granted> <con1, X REC_NOT_GAP, granted> <con2, X, waiting> <con3, X, waiting>
--connection con1
  BEGIN;
  SELECT * FROM t1 LOCK IN SHARE MODE;

--connection con2
  SET DEBUG_SYNC = 'lock_wait_before_suspend SIGNAL con2_will_wait';
  --send SELECT * FROM t1 FOR UPDATE

--connection con3
  SET DEBUG_SYNC = 'now WAIT_FOR con2_will_wait';
  SET DEBUG_SYNC = 'lock_wait_before_suspend SIGNAL con3_will_wait';
  --send SELECT * FROM t1 FOR UPDATE

--connection con1
  SET DEBUG_SYNC = 'now WAIT_FOR con3_will_wait';
  SELECT * FROM t1 WHERE id=1 FOR UPDATE;
  COMMIT;

--connection con2
  --reap
  COMMIT;

--connection con3
  --reap
  COMMIT;

--connection default
--disconnect con1
--disconnect con2
--disconnect con3
--disconnect stop_purge

DROP TABLE t1;

--source include/wait_until_count_sessions.inc