--echo #Test for Intention Shared lock

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

--disable_warnings
drop table if exists t1_is;
--enable_warnings

--connection con1
use test;
create table t1_is (id integer, x integer, PRIMARY KEY (id)) engine=INNODB;
insert into t1_is values (0,0),(1,1);
SET autocommit=0;
begin;
select * from t1_is where id=0 FOR SHARE;

--connection con2
begin;
select * from t1_is;
--send
update t1_is set x = 2 where id = 0;

--connection con3

#
# WARNING
# =======
#
# Spurious failures possible on column LOCK_DATA
#
# One one hand, for the innodb storage engine,
# the server returns the LOCK_DATA column using
# 'best effort', without guarantees.
# See in innodb:
# - Innodb_data_lock_iterator::scan_trx()
# - p_s_fill_lock_data()
# - buf_page_try_get()
#
# In short, if the page is in the buffer pool,
# LOCK_DATA for the record is returned.
# However, if the page is not in the buffer pool,
# the code just returns LOCK_DATA = NULL
# instead of re-loading the page from disk just
# to read LOCK_DATA.
#
# On the other hand, the point of this test
# is to inspect LOCK_DATA returned in the
# performance schema, to make sure the proper
# record lock is printed.
#
# Note that a NULL is a valid result, not a failure.
#
# Due to connection con2 doing a select,
# the hope is that this test produces predictable results.

# Wait for con2 to block
let $wait_condition= SELECT COUNT(*) = 1  FROM performance_schema.data_locks
  where object_name="t1_is" and lock_type = "RECORD"
  and lock_mode = "X,REC_NOT_GAP" and lock_status = "WAITING";
--source include/wait_condition.inc

begin;

select object_schema, object_name, lock_type, lock_mode, lock_status, lock_data
  from performance_schema.data_locks
  where object_name="t1_is"
  order by lock_type, lock_mode, lock_status, lock_data;

# Repeat
select object_schema, object_name, lock_type, lock_mode, lock_status, lock_data
  from performance_schema.data_locks
  where object_name="t1_is"
  order by lock_type, lock_mode, lock_status, lock_data;

select count(*) into @health_check
  from performance_schema.data_locks where object_name="t1_is";

commit;

#
# Somehow Intention Shared / Shared locks
# are not always reported, causing spurious test failures.
# Dumping debug data to help diagnosis.
#

if (`select @health_check != 4`)
{
  --echo "TEST FAILED, DUMPING DATA TO DEBUG"
  select @health_check;
  select * from performance_schema.data_locks;
  select * from performance_schema.data_lock_waits;
}

--connection con1
commit;

--connection con2
--reap
commit;

--connection default
drop table t1_is;

--disconnect con1
--disconnect con2
--disconnect con3