mariadb/mysql-test/main/mdl_sync.test

#
# We need the Debug Sync Facility.
#
--source include/have_debug_sync.inc

# We need InnoDB tables for some of the tests.
--source include/have_innodb.inc

# Save the initial number of concurrent sessions.
--source include/count_sessions.inc


# Clean up resources used in this test case.
--disable_warnings
SET DEBUG_SYNC= 'RESET';
--enable_warnings

#
# Test the case of when a exclusive lock request waits for a
# shared lock being upgraded to a exclusive lock.
#

connect (con1,localhost,root,,test,,);
connect (con2,localhost,root,,test,,);
connect (con3,localhost,root,,test,,);

connection default;

--disable_warnings
drop table if exists t1,t2,t3;
--enable_warnings

create table t1 (i int);
create table t2 (i int);

--echo connection: default
lock tables t2 read;

connection con1;
--echo connection: con1
set debug_sync='mdl_upgrade_lock SIGNAL parked WAIT_FOR go';
--send alter table t1 rename t3

connection default;
--echo connection: default
set debug_sync= 'now WAIT_FOR parked';

connection con2;
--echo connection: con2
set debug_sync='mdl_acquire_lock_wait SIGNAL go';
--send drop table t1,t2

connection con1;
--echo connection: con1
--reap

connection default;
--echo connection: default
unlock tables;

connection con2;
--echo connection: con2
--error ER_BAD_TABLE_ERROR
--reap

connection default;
drop table t3;

disconnect con1;
disconnect con2;
disconnect con3;

# Clean up resources used in this test case.
--disable_warnings
SET DEBUG_SYNC= 'RESET';
--enable_warnings


--echo #
--echo # Basic test coverage for type-of-operation aware metadata locks.
--echo #
--disable_warnings
drop table if exists t1, t2, t3;
--enable_warnings
connect(mdl_con1,localhost,root,,);
connect(mdl_con2,localhost,root,,);
connect(mdl_con3,localhost,root,,);
connection default;
set debug_sync= 'RESET';
create table t1 (c1 int);

--echo # 
--echo # A) First let us check compatibility rules between differend kinds of
--echo #    type-of-operation aware metadata locks.
--echo #    Of course, these rules are already covered by the tests scattered
--echo #    across the test suite. But it still makes sense to have one place
--echo #    which covers all of them.
--echo #

--echo # 1) Acquire S (simple shared) lock on the table (by using HANDLER):
--echo #
handler t1 open;
--echo # 
connection mdl_con1;
--echo # Check that S, SH, SR and SW locks are compatible with it.
handler t1 open t;
handler t close;
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
select count(*) from t1;
insert into t1 values (1), (1);
--echo # Check that SU lock is compatible with it. To do this use ALTER TABLE
--echo # which will fail when constructing .frm and thus obtaining SU metadata
--echo # lock.
--error ER_KEY_COLUMN_DOES_NOT_EXITS
alter table t1 add index (not_exist);
--echo # Check that SNW lock is compatible with it. To do this use ALTER TABLE
--echo # which will fail during copying the table and thus obtaining SNW metadata
--echo # lock.
--error ER_DUP_ENTRY
alter table t1 add primary key (c1);
--echo # Check that X lock is incompatible with S lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con2;
--echo # Check that the above RENAME is blocked because of S lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # 
connection default;
--echo # Unblock RENAME TABLE.
handler t1 close;
--echo # 
connection mdl_con1;
--echo # Reaping RENAME TABLE.
--reap
--echo # Restore the original state of the things.
rename table t2 to t1;
--echo # 
connection default;
handler t1 open;
--echo # 
connection mdl_con1;
--echo # Check that upgrade from SNW to X is blocked by presence of S lock.
--echo # Sending:
--send alter table t1 add column c2 int;
--echo # 
connection mdl_con2;
--echo # Check that the above ALTER TABLE is blocked because of S lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 add column c2 int";
--source include/wait_condition.inc
--echo # 
connection default;
--echo # Unblock ALTER TABLE.
handler t1 close;
--echo # 
connection mdl_con1;
--echo # Reaping ALTER TABLE.
--reap
--echo # Restore the original state of the things.
alter table t1 drop column c2;
--echo # 
connection default;
--echo #
--echo # 2) Acquire SH (shared high-priority) lock on the table.
--echo #    We have to involve DEBUG_SYNC facility for this as usually
--echo #    such kind of locks are short-lived.
--echo #
set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send select table_name, table_type, auto_increment, table_comment from information_schema.tables where table_schema='test' and table_name='t1';
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that S, SH, SR and SW locks are compatible with it.
handler t1 open;
handler t1 close;
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
select count(*) from t1;
insert into t1 values (1);
--echo # Check that SU lock is compatible with it. To do this use ALTER TABLE
--echo # which will fail when constructing .frm and thus obtaining SU metadata
--echo # lock.
--error ER_KEY_COLUMN_DOES_NOT_EXITS
alter table t1 add index (not_exist);
--echo # Check that SNW lock is compatible with it. To do this use ALTER TABLE
--echo # which will fail during copying the table and thus obtaining SNW metadata
--echo # lock.
--error ER_DUP_ENTRY
alter table t1 add primary key (c1);
--echo # Check that SNRW lock is compatible with SH lock.
lock table t1 write;
delete from t1 limit 1;
unlock tables;
--echo # Check that X lock is incompatible with SH lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con2;
--echo # Check that the above RENAME is blocked because of SH lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Reaping SELECT ... FROM I_S.
--reap
--echo # 
connection mdl_con1;
--echo # Reaping RENAME TABLE.
--reap
--echo # Restore the original state of the things.
rename table t2 to t1;
--echo # 
connection default;
set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send select table_name, table_type, auto_increment, table_comment from information_schema.tables where table_schema='test' and table_name='t1';
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that upgrade from SNW to X is blocked by presence of SH lock.
--echo # Sending:
--send alter table t1 add column c2 int;
--echo # 
connection mdl_con2;
--echo # Check that the above ALTER TABLE is blocked because of SH lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 add column c2 int";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Reaping SELECT ... FROM I_S.
--reap
--echo # 
connection mdl_con1;
--echo # Reaping ALTER TABLE.
--reap
--echo # Restore the original state of the things.
alter table t1 drop column c2;
--echo # 
connection default;
set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish';
--send select table_name, table_type, auto_increment, table_comment from information_schema.tables where table_schema='test' and table_name='t1';
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that upgrade from SNRW to X is blocked by presence of S lock.
lock table t1 write;
--echo # Sending:
--send alter table t1 add column c2 int;
--echo # 
connection mdl_con2;
--echo # Check that the above upgrade of SNRW to X in ALTER TABLE is blocked
--echo # because of S lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 add column c2 int";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Reaping SELECT ... FROM I_S.
--reap
--echo # 
connection mdl_con1;
--echo # Reaping ALTER TABLE.
--reap
--echo # Restore the original state of the things.
alter table t1 drop column c2;
unlock tables;
--echo # 
connection default;
--echo #
--echo #
--echo # 3) Acquire SR lock on the table.
--echo #
--echo #
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
--echo # Check that S, SH, SR and SW locks are compatible with it.
handler t1 open;
handler t1 close;
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
select count(*) from t1;
insert into t1 values (1);
--echo # Check that SU lock is compatible with it. To do this use ALTER TABLE
--echo # which will fail when constructing .frm and thus obtaining SU metadata
--echo # lock.
--error ER_KEY_COLUMN_DOES_NOT_EXITS
alter table t1 add index (not_exist);
--echo # Check that SNW lock is compatible with it. To do this use ALTER TABLE
--echo # which will fail during copying the table and thus obtaining SNW metadata
--echo # lock.
--error ER_DUP_ENTRY
alter table t1 add primary key (c1);
--echo # Check that SNRW lock is not compatible with SR lock.
--echo # Sending:
--send lock table t1 write;
--echo # 
connection default;
--echo # Check that the above LOCK TABLES is blocked because of SR lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and 
        info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Unblock LOCK TABLES.
commit;
--echo # 
connection mdl_con1;
--echo # Reaping LOCK TABLES.
--reap
delete from t1 limit 1;
unlock tables;
--echo # 
connection default;
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
--echo # Check that X lock is incompatible with SR lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con2;
--echo # Check that the above RENAME is blocked because of SR lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # 
connection default;
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reaping RENAME TABLE.
--reap
--echo # Restore the original state of the things.
rename table t2 to t1;
--echo # 
connection default;
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
--echo # Check that upgrade from SNW to X is blocked by presence of SR lock.
--echo # Sending:
--send alter table t1 add column c2 int;
--echo # 
connection mdl_con2;
--echo # Check that the above ALTER TABLE is blocked because of SR lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 add column c2 int";
--source include/wait_condition.inc
--echo # 
connection default;
--echo # Unblock ALTER TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reaping ALTER TABLE.
--reap
--echo # Restore the original state of the things.
alter table t1 drop column c2;
--echo #
--echo # There is no need to check that upgrade from SNRW to X is blocked
--echo # by presence of SR lock because SNRW is incompatible with SR anyway.
--echo # 
--echo # 
connection default;
--echo #
--echo #
--echo # 4) Acquire SW lock on the table.
--echo #
--echo #
begin;
insert into t1 values (1);
--echo # 
connection mdl_con1;
--echo # Check that S, SH, SR and SW locks are compatible with it.
handler t1 open;
handler t1 close;
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
--echo # Disable result log to make test robust against
--echo # effects of concurrent insert.
--disable_result_log
select * from t1;
--enable_result_log
insert into t1 values (1);
--echo # Check that SU lock is compatible with it. To do this use ALTER TABLE
--echo # which will fail when constructing .frm and thus obtaining SU metadata
--echo # lock.
--error ER_KEY_COLUMN_DOES_NOT_EXITS
alter table t1 add index (not_exist);
--echo # Check that SNW lock is not compatible with SW lock.
--echo # Again we use ALTER TABLE which fails during copying
--echo # the table to avoid upgrade of SNW -> X.
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection default;
--echo # Check that the above ALTER TABLE is blocked because of SW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 add primary key (c1)";
--source include/wait_condition.inc
--echo # Unblock ALTER TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reaping ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection default;
begin;
insert into t1 values (1);
--echo # 
connection mdl_con1;
--echo # Check that SNRW lock is not compatible with SW lock.
--echo # Sending:
--send lock table t1 write;
--echo # 
connection default;
--echo # Check that the above LOCK TABLES is blocked because of SW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Unblock LOCK TABLES.
commit;
--echo # 
connection mdl_con1;
--echo # Reaping LOCK TABLES.
--reap
delete from t1 limit 2;
unlock tables;
--echo # 
connection default;
begin;
insert into t1 values (1);
--echo # 
connection mdl_con1;
--echo # Check that X lock is incompatible with SW lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con2;
--echo # Check that the above RENAME is blocked because of SW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # 
connection default;
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reaping RENAME TABLE.
--reap
--echo # Restore the original state of the things.
rename table t2 to t1;
--echo #
--echo # There is no need to check that upgrade from SNW/SNRW to X is
--echo # blocked by presence of SW lock because SNW/SNRW is incompatible
--echo # with SW anyway.
--echo # 
--echo # 
connection default;
--echo #
--echo #
--echo # 5) Acquire SU lock on the table. We have to use DEBUG_SYNC for
--echo #    this, to prevent SU from being immediately upgraded to X.
--echo #
set debug_sync= 'alter_opened_table SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that S, SH, SR and SW locks are compatible with it.
handler t1 open;
handler t1 close;
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
select count(*) from t1;
delete from t1 limit 1;
--echo # Check that SU lock is incompatible with SU lock.
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection mdl_con2;
--echo # Check that the above ALTER is blocked because of SU lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 add primary key (c1)";
--source include/wait_condition.inc
--echo # Unblock ALTERs.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Reaping first ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection mdl_con1;
--echo # Reaping another ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection default;
set debug_sync= 'alter_opened_table SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that SNRW lock is incompatible with SU lock.
--echo # Sending:
--send lock table t1 write;
--echo # 
connection mdl_con2;
--echo # Check that the above LOCK TABLES is blocked because of SU lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Unblock ALTER and thus LOCK TABLES.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Reaping ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection mdl_con1;
--echo # Reaping LOCK TABLES
--reap
insert into t1 values (1);
unlock tables;
--echo # 
connection default;
set debug_sync= 'alter_opened_table SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that X lock is incompatible with SU lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con2;
--echo # Check that the above RENAME is blocked because of SU lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Unblock ALTER and thus RENAME TABLE.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Now we have ALTER TABLE with SU->SNW and RENAME TABLE with pending
--echo # X-lock. In this case ALTER TABLE should be chosen as victim.
--echo # Reaping ALTER TABLE.
--error ER_LOCK_DEADLOCK
--reap
--echo # 
connection mdl_con1;
--echo # Reaping RENAME TABLE
--reap
--echo # Revert back to original state of things.
rename table t2 to t1;
--echo #
--echo # There is no need to check that upgrade from SNW/SNRW to X is
--echo # blocked by presence of another SU lock because SNW/SNRW is
--echo # incompatible with SU anyway.
--echo # 
connection default;
--echo #
--echo #
--echo # 6) Acquire SNW lock on the table. We have to use DEBUG_SYNC for
--echo #    this, to prevent SNW from being immediately upgraded to X.
--echo #
set debug_sync= 'alter_table_copy_after_lock_upgrade SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send alter table t1 add primary key (c1), lock=shared, algorithm=copy;
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that S, SH and SR locks are compatible with it.
handler t1 open;
handler t1 close;
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
select count(*) from t1;
--echo # Check that SW lock is incompatible with SNW lock.
--echo # Sending:
--send delete from t1 limit 2;
--echo # 
connection mdl_con2;
--echo # Check that the above DELETE is blocked because of SNW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "delete from t1 limit 2";
--source include/wait_condition.inc
--echo # Unblock ALTER and thus DELETE.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Reaping ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection mdl_con1;
--echo # Reaping DELETE.
--reap
--echo # 
connection default;
set debug_sync= 'alter_table_copy_after_lock_upgrade SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send alter table t1 add primary key (c1), lock=shared, algorithm=copy;
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that SU lock is incompatible with SNW lock.
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection mdl_con2;
--echo # Check that the above ALTER is blocked because of SNW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 add primary key (c1)";
--source include/wait_condition.inc
--echo # Unblock ALTERs.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Reaping first ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection mdl_con1;
--echo # Reaping another ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
--echo # Note that we can't easily check SNW vs SNW locks since
--echo # SNW is only used by ALTER TABLE after upgrading from SU
--echo # and SU is also incompatible with SNW.
--echo #
connection default;
set debug_sync= 'alter_table_copy_after_lock_upgrade SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send alter table t1 add primary key (c1), lock=shared, algorithm=copy;
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that SNRW lock is incompatible with SNW lock.
--echo # Sending:
--send lock table t1 write;
--echo # 
connection mdl_con2;
--echo # Check that the above LOCK TABLES is blocked because of SNW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Unblock ALTER and thus LOCK TABLES.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Reaping ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection mdl_con1;
--echo # Reaping LOCK TABLES
--reap
insert into t1 values (1);
unlock tables;
--echo # 
connection default;
set debug_sync= 'alter_table_copy_after_lock_upgrade SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send alter table t1 add primary key (c1), algorithm=copy, lock=shared;
--echo # 
connection mdl_con1;
set debug_sync= 'now WAIT_FOR locked';
--echo # Check that X lock is incompatible with SNW lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con2;
--echo # Check that the above RENAME is blocked because of SNW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Unblock ALTER and thus RENAME TABLE.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection default;
--echo # Reaping ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection mdl_con1;
--echo # Reaping RENAME TABLE
--reap
--echo # Revert back to original state of things.
rename table t2 to t1;
--echo #
--echo # There is no need to check that upgrade from SNW/SNRW to X is
--echo # blocked by presence of another SNW lock because SNW/SNRW is
--echo # incompatible with SNW anyway.
--echo # 
connection default;
--echo #
--echo #
--echo # 7) Acquire SNRW lock on the table. 
--echo #
--echo #
lock table t1 write;
--echo # 
connection mdl_con1;
--echo # Check that S and SH locks are compatible with it.
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
--echo # Check that SR lock is incompatible with SNRW lock.
--echo # Sending:
--send select count(*) from t1;
--echo # 
connection default;
--echo # Check that the above SELECT is blocked because of SNRW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "select count(*) from t1";
--source include/wait_condition.inc
--echo # Unblock SELECT.
unlock tables;
--echo # 
connection mdl_con1;
--echo # Reaping SELECT.
--reap
--echo # 
connection default;
lock table t1 write;
--echo # 
connection mdl_con1;
--echo # Check that SW lock is incompatible with SNRW lock.
--echo # Sending:
--send delete from t1 limit 1;
--echo # 
connection default;
--echo # Check that the above DELETE is blocked because of SNRW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "delete from t1 limit 1";
--source include/wait_condition.inc
--echo # Unblock DELETE.
unlock tables;
--echo # 
connection mdl_con1;
--echo # Reaping DELETE.
--reap
--echo # 
connection default;
lock table t1 write;
--echo # 
connection mdl_con1;
--echo # Check that SU lock is incompatible with SNRW lock.
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection default;
--echo # Check that the above ALTER is blocked because of SNRW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 add primary key (c1)";
--source include/wait_condition.inc
--echo # Unblock ALTER.
unlock tables;
--echo # 
connection mdl_con1;
--echo # Reaping ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
--echo # Note that we can't easily check SNW vs SNRW locks since
--echo # SNW is only used by ALTER TABLE after upgrading from SU
--echo # and SU is also incompatible with SNRW.
--echo #
connection default;
lock table t1 write;
--echo # 
connection mdl_con1;
--echo # Check that SNRW lock is incompatible with SNRW lock.
--echo # Sending:
--send lock table t1 write;
--echo # 
connection default;
--echo # Check that the above LOCK TABLES is blocked because of SNRW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Unblock waiting LOCK TABLES.
unlock tables;
--echo # 
connection mdl_con1;
--echo # Reaping LOCK TABLES
--reap
insert into t1 values (1);
unlock tables;
--echo # 
connection default;
lock table t1 write;
--echo # 
connection mdl_con1;
--echo # Check that X lock is incompatible with SNRW lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection default;
--echo # Check that the above RENAME is blocked because of SNRW lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE
unlock tables;
--echo # 
connection mdl_con1;
--echo # Reaping RENAME TABLE
--reap
--echo # Revert back to original state of things.
rename table t2 to t1;
--echo #
--echo # There is no need to check that upgrade from SNW/SNRW to X is
--echo # blocked by presence of another SNRW lock because SNW/SNRW is
--echo # incompatible with SNRW anyway.
--echo # 
connection default;
--echo #
--echo #
--echo # 8) Now do the same round of tests for X lock. We use additional
--echo #    table to get long-lived lock of this type.
--echo #
create table t2 (c1 int);
--echo # 
connection mdl_con2;
--echo # Take a lock on t2, so RENAME TABLE t1 TO t2 will get blocked
--echo # after acquiring X lock on t1.
lock tables t2 read;
--echo # 
connection default;
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME has acquired X lock on t1 and is waiting for t2.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that S lock in incompatible with X lock.
--echo # Sending:
--send handler t1 open;
--echo # 
connection mdl_con2;
--echo # Check that the above HANDLER statement is blocked because of X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "handler t1 open";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE
unlock tables;
--echo # 
connection default;
--echo # Reaping RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping HANDLER.
--reap
handler t1 close;
--echo # 
connection mdl_con2;
--echo # Prepare for blocking RENAME TABLE.
lock tables t2 read;
--echo # 
connection default;
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME has acquired X lock on t1 and is waiting for t2.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SH lock in incompatible with X lock.
--echo # Sending:
--send select column_name from information_schema.columns where table_schema='test' and table_name='t1';
--echo # 
connection mdl_con2;
--echo # Check that the above SELECT ... FROM I_S ... statement is blocked
--echo # because of X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info like "select column_name from information_schema.columns%";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE
unlock tables;
--echo # 
connection default;
--echo # Reaping RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping SELECT ... FROM I_S.
--reap
--echo # 
connection mdl_con2;
--echo # Prepare for blocking RENAME TABLE.
lock tables t2 read;
--echo # 
connection default;
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME has acquired X lock on t1 and is waiting for t2.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SR lock in incompatible with X lock.
--echo # Sending:
--send select count(*) from t1;
--echo # 
connection mdl_con2;
--echo # Check that the above SELECT statement is blocked
--echo # because of X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and 
      info = "select count(*) from t1";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE
unlock tables;
--echo # 
connection default;
--echo # Reaping RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping SELECT.
--reap
--echo # 
connection mdl_con2;
--echo # Prepare for blocking RENAME TABLE.
lock tables t2 read;
--echo # 
connection default;
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME has acquired X lock on t1 and is waiting for t2.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SW lock in incompatible with X lock.
--echo # Sending:
--send delete from t1 limit 1;
--echo # 
connection mdl_con2;
--echo # Check that the above DELETE statement is blocked
--echo # because of X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "delete from t1 limit 1";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE
unlock tables;
--echo # 
connection default;
--echo # Reaping RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping DELETE.
--reap
--echo # 
connection mdl_con2;
--echo # Prepare for blocking RENAME TABLE.
lock tables t2 read;
--echo # 
connection default;
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME has acquired X lock on t1 and is waiting for t2.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SU lock is incompatible with X lock.
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection mdl_con2;
--echo # Check that the above ALTER statement is blocked
--echo # because of X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "alter table t1 add primary key (c1)";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE
unlock tables;
--echo # 
connection default;
--echo # Reaping RENAME TABLE
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping ALTER.
--error ER_DUP_ENTRY
--reap
--echo #
--echo # Note that we can't easily check SNW vs X locks since
--echo # SNW is only used by ALTER TABLE after upgrading from SU
--echo # and SU is also incompatible with X.
--echo #
connection mdl_con2;
--echo # Prepare for blocking RENAME TABLE.
lock tables t2 read;
--echo # 
connection default;
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME has acquired X lock on t1 and is waiting for t2.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SNRW lock is incompatible with X lock.
--echo # Sending:
--send lock table t1 write;
--echo # 
connection mdl_con2;
--echo # Check that the above LOCK TABLE statement is blocked
--echo # because of X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE
unlock tables;
--echo # 
connection default;
--echo # Reaping RENAME TABLE
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping LOCK TABLE.
--reap
unlock tables;
--echo # 
connection mdl_con2;
--echo # Prepare for blocking RENAME TABLE.
lock tables t2 read;
--echo # 
connection default;
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME has acquired X lock on t1 and is waiting for t2.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that X lock is incompatible with X lock.
--echo # Sending:
--send rename table t1 to t3;
--echo # 
connection mdl_con2;
--echo # Check that the above RENAME statement is blocked
--echo # because of X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t3";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE
unlock tables;
--echo # 
connection default;
--echo # Reaping RENAME TABLE
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping RENAME.
--reap
rename table t3 to t1;

--echo #
--echo # B) Now let us test compatibility in cases when both locks
--echo #    are pending. I.e. let us test rules for priorities between
--echo #    different types of metadata locks.
--echo #
--echo #    Note: No tests for pending SU lock as this lock requires
--echo #          even stronger active or pending lock.
--echo #

--echo # 
connection mdl_con2;
--echo #
--echo # 1) Check compatibility for pending SNW lock.
--echo #
--echo # Acquire SW lock in order to create pending SNW lock later.
begin;
insert into t1 values (1);
--echo # 
connection default;
--echo # Add pending SNW lock.
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection mdl_con1;
--echo # Check that ALTER TABLE is waiting with pending SNW lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "alter table t1 add primary key (c1)";
--source include/wait_condition.inc
--echo # Check that S, SH and SR locks are compatible with pending SNW
handler t1 open t;
handler t close;
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
select count(*) from t1;
--echo # Check that SW is incompatible with pending SNW
--echo # Sending:
--send delete from t1 limit 1;
--echo # 
connection mdl_con2;
--echo # Check that the above DELETE is blocked because of pending SNW lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "delete from t1 limit 1";
--source include/wait_condition.inc
--echo # Unblock ALTER TABLE.
commit;
--echo # 
connection default;
--echo # Reaping ALTER.
--error ER_DUP_ENTRY
--reap
--echo # 
connection mdl_con1;
--echo # Reaping DELETE.
--reap
--echo #
--echo # We can't do similar check for SNW, SNRW and X locks because
--echo # they will also be blocked by active SW lock.
--echo #
--echo # 
connection mdl_con2;
--echo #
--echo # 2) Check compatibility for pending SNRW lock.
--echo #
--echo # Acquire SR lock in order to create pending SNRW lock.
begin;
select count(*) from t1;
--echo # 
connection default;
--echo # Add pending SNRW lock.
--echo # Sending:
--send lock table t1 write;
--echo # 
connection mdl_con1;
--echo # Check that LOCK TABLE is waiting with pending SNRW lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Check that S and SH locks are compatible with pending SNRW
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
--echo # Check that SR is incompatible with pending SNRW
--echo # Sending:
--send select count(*) from t1;
--echo # 
connection mdl_con2;
--echo # Check that the above SELECT is blocked because of pending SNRW lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "select count(*) from t1";
--source include/wait_condition.inc
--echo # Unblock LOCK TABLE.
commit;
--echo # 
connection default;
--echo # Reaping LOCK TABLE.
--reap
unlock tables;
--echo # 
connection mdl_con1;
--echo # Reaping SELECT.
--reap
--echo # Restore pending SNRW lock.
--echo # 
connection mdl_con2;
begin;
select count(*) from t1;
--echo # 
connection default;
--echo # Sending:
--send lock table t1 write;
--echo # 
connection mdl_con1;
--echo # Check that LOCK TABLE is waiting with pending SNRW lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Check that SW is incompatible with pending SNRW
--echo # Sending:
--send insert into t1 values (1);
--echo # 
connection mdl_con2;
--echo # Check that the above INSERT is blocked because of pending SNRW lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "insert into t1 values (1)";
--source include/wait_condition.inc
--echo # Unblock LOCK TABLE.
commit;
--echo # 
connection default;
--echo # Reaping LOCK TABLE.
--reap
unlock tables;
--echo # 
connection mdl_con1;
--echo # Reaping INSERT.
--reap
--echo # Restore pending SNRW lock.
--echo # 
connection mdl_con2;
begin;
select count(*) from t1;
--echo # 
connection default;
--echo # Sending:
--send lock table t1 write;
--echo # 
connection mdl_con1;
--echo # Check that LOCK TABLE is waiting with pending SNRW lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Check that SNW is compatible with pending SNRW
--echo # So ALTER TABLE statements are not starved by LOCK TABLEs.
--error ER_DUP_ENTRY
alter table t1 add primary key (c1);
--echo # 
connection mdl_con2;
--echo # Unblock LOCK TABLE.
commit;
--echo # 
connection default;
--echo # Reaping LOCK TABLE.
--reap
unlock tables;
--echo #
--echo # We can't do similar check for SNRW and X locks because
--echo # they will also be blocked by active SR lock.
--echo #
--echo # 
connection mdl_con2;
--echo #
--echo # 3) Check compatibility for pending X lock.
--echo #
--echo # Acquire SR lock in order to create pending X lock.
begin;
select count(*) from t1;
--echo # 
connection default;
--echo # Add pending X lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME TABLE is waiting with pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SH locks are compatible with pending X
select column_name from information_schema.columns where
  table_schema='test' and table_name='t1';
--echo # Check that S is incompatible with pending X
--echo # Sending:
--send handler t1 open;
--echo # 
connection mdl_con2;
--echo # Check that the above HANDLER OPEN is blocked because of pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "handler t1 open";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection default;
--echo # Reaping RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping HANDLER t1 OPEN.
--reap
handler t1 close;
--echo # Restore pending X lock.
--echo # 
connection mdl_con2;
begin;
select count(*) from t1;
--echo # 
connection default;
--echo # Add pending X lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME TABLE is waiting with pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SR is incompatible with pending X
--echo # Sending:
--send select count(*) from t1;
--echo # 
connection mdl_con2;
--echo # Check that the above SELECT is blocked because of pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "select count(*) from t1";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection default;
--echo # Reaping RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping SELECT.
--reap
--echo # Restore pending X lock.
--echo # 
connection mdl_con2;
begin;
select count(*) from t1;
--echo # 
connection default;
--echo # Add pending X lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME TABLE is waiting with pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SW is incompatible with pending X
--echo # Sending:
--send delete from t1 limit 1;
--echo # 
connection mdl_con2;
--echo # Check that the above DELETE is blocked because of pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "delete from t1 limit 1";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection default;
--echo # Reaping RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping DELETE.
--reap
--echo # Restore pending X lock.
--echo # 
connection mdl_con2;
begin;
select count(*) from t1;
--echo # 
connection default;
--echo # Add pending X lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME TABLE is waiting with pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SNW is incompatible with pending X
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection mdl_con2;
--echo # Check that the above ALTER TABLE is blocked because of pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "alter table t1 add primary key (c1)";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection default;
--echo # Reaping RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # Restore pending X lock.
--echo # 
connection mdl_con2;
handler t1 open;
--echo # 
connection default;
--echo # Add pending X lock.
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection mdl_con1;
--echo # Check that RENAME TABLE is waiting with pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that SNRW is incompatible with pending X
--echo # Sending:
--send lock table t1 write;
--echo # 
connection mdl_con3;
--echo # Check that the above LOCK TABLES is blocked because of pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "lock table t1 write";
--source include/wait_condition.inc
--echo # 
connection mdl_con2;
--echo # Unblock RENAME TABLE.
handler t1 close;
--echo # 
connection default;
--echo # Reaping RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection mdl_con1;
--echo # Reaping LOCK TABLES.
--reap
unlock tables;
--echo # 
connection default;

--echo #
--echo #
--echo # C) Now let us test how type-of-operation locks are handled in
--echo #    transactional context. Obviously we are mostly interested
--echo #    in conflicting types of locks.
--echo #
--echo #    Note: No tests for active/pending SU lock since
--echo #          ALTER TABLE is in its own transaction.
--echo #

--echo #
--echo # 1) Let us check how various locks used within transactional
--echo #    context interact with active/pending SNW lock.
--echo #
--echo #    We start with case when we are acquiring lock on the table
--echo #    which was not used in the transaction before.
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
--echo # Create an active SNW lock on t2.
--echo # We have to use DEBUG_SYNC facility as otherwise SNW lock
--echo # will be immediately released (or upgraded to X lock).
insert into t2 values (1), (1);
set debug_sync= 'alter_table_copy_after_lock_upgrade SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send alter table t2 add primary key (c1), algorithm=copy, lock=shared;
--echo # 
connection default;
set debug_sync= 'now WAIT_FOR locked';
--echo # SR lock should be acquired without any waiting.
select count(*) from t2;
commit;
--echo # Now let us check that we will wait in case of SW lock.
begin;
select count(*) from t1;
--echo # Sending:
--send insert into t2 values (1);
--echo # 
connection mdl_con2;
--echo # Check that the above INSERT is blocked.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "insert into t2 values (1)";
--source include/wait_condition.inc
--echo # Unblock ALTER TABLE and thus INSERT.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection mdl_con1;
--echo # Reap ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection default;
--echo # Reap INSERT.
--reap
commit;
--echo #
--echo # Now let us see what happens when we are acquiring lock on the table
--echo # which is already used in transaction.
--echo #
--echo # *) First, case when transaction which has SR lock on the table also
--echo #    locked in SNW mode acquires yet another SR lock and then tries
--echo #    to acquire SW lock.
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
--echo # Create an active SNW lock on t1.
set debug_sync= 'alter_table_copy_after_lock_upgrade SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send alter table t1 add primary key (c1), algorithm=copy, lock=shared;
--echo # 
connection default;
set debug_sync= 'now WAIT_FOR locked';
--echo # We should still be able to get SR lock without waiting.
select count(*) from t1;
--echo # Since the above ALTER TABLE is not upgrading SNW lock to X by waiting
--echo # for SW lock we won't create deadlock.
--echo # So the below INSERT should not end-up with ER_LOCK_DEADLOCK error.
--echo # Sending:
--send insert into t1 values (1);
--echo # 
connection mdl_con2;
--echo # Check that the above INSERT is blocked.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "insert into t1 values (1)";
--source include/wait_condition.inc
--echo # Unblock ALTER TABLE and thus INSERT.
set debug_sync= 'now SIGNAL finish';
--echo # 
connection mdl_con1;
--echo # Reap ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection default;
--echo # Reap INSERT.
--reap
commit;
--echo #
--echo # **) Now test in which transaction that has SW lock on the table
--echo #     against which there is pending SNW lock acquires SR and SW
--echo #     locks on this table.
--echo #
begin;
insert into t1 values (1);
--echo # 
connection mdl_con1;
--echo # Create pending SNW lock on t1.
--echo # Sending:
--send alter table t1 add primary key (c1);
--echo # 
connection default;
--echo # Wait until ALTER TABLE starts waiting for SNW lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "alter table t1 add primary key (c1)";
--source include/wait_condition.inc
--echo # We should still be able to get both SW and SR locks without waiting.
select count(*) from t1;
delete from t1 limit 1;
--echo # Unblock ALTER TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reap ALTER TABLE.
--error ER_DUP_ENTRY
--reap
--echo # 
connection default;
--echo #
--echo # 2) Now similar tests for active SNW lock which is being upgraded
--echo #    to X lock.
--echo #
--echo #    Again we start with case when we are acquiring lock on the
--echo #    table which was not used in the transaction before.
begin;
select count(*) from t1;
--echo # 
connection mdl_con2;
--echo # Start transaction which will prevent SNW -> X upgrade from
--echo # completing immediately.
begin;
select count(*) from t2;
--echo # 
connection mdl_con1;
--echo # Create SNW lock pending upgrade to X on t2.
--echo # Sending:
--send alter table t2 add column c2 int;
--echo # 
connection default;
--echo # Wait until ALTER TABLE starts waiting X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "alter table t2 add column c2 int";
--source include/wait_condition.inc
--echo # Check that attempt to acquire SR lock on t2 causes waiting.
--echo # Sending:
--send select count(*) from t2;
--echo # 
connection mdl_con2;
--echo # Check that the above SELECT is blocked.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "select count(*) from t2";
--source include/wait_condition.inc
--echo # Unblock ALTER TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reap ALTER TABLE.
--reap
--echo # 
connection default;
--echo # Reap SELECT.
--reap
commit;
--echo # Do similar check for SW lock.
begin;
select count(*) from t1;
--echo # 
connection mdl_con2;
--echo # Start transaction which will prevent SNW -> X upgrade from
--echo # completing immediately.
begin;
select count(*) from t2;
--echo # 
connection mdl_con1;
--echo # Create SNW lock pending upgrade to X on t2.
--echo # Sending:
--send alter table t2 drop column c2;
--echo # 
connection default;
--echo # Wait until ALTER TABLE starts waiting X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "alter table t2 drop column c2";
--source include/wait_condition.inc
--echo # Check that attempt to acquire SW lock on t2 causes waiting.
--echo # Sending:
--send insert into t2 values (1);
--echo # 
connection mdl_con2;
--echo # Check that the above INSERT is blocked.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "insert into t2 values (1)";
--source include/wait_condition.inc
--echo # Unblock ALTER TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reap ALTER TABLE.
--reap
--echo # 
connection default;
--echo # Reap INSERT.
--reap
commit;
--echo #
--echo # Test for the case in which we are acquiring lock on the table
--echo # which is already used in transaction.
--echo #
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
--echo # Create SNW lock pending upgrade to X.
--echo # Sending:
--send alter table t1 add column c2 int;
--echo # 
connection default;
--echo # Wait until ALTER TABLE starts waiting X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "alter table t1 add column c2 int";
--source include/wait_condition.inc
--echo # Check that transaction is still able to acquire SR lock.
select count(*) from t1;
--echo # Waiting trying to acquire SW lock will cause deadlock and
--echo # therefore should cause an error.
--error ER_LOCK_DEADLOCK
delete from t1 limit 1;
--echo # Unblock ALTER TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reap ALTER TABLE.
--reap
--echo # 
connection default;
--echo #
--echo # 3) Check how various locks used within transactional context
--echo #    interact with active/pending SNRW lock.
--echo # 
--echo #    Once again we start with case when we are acquiring lock on
--echo #    the table which was not used in the transaction before.
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
lock table t2 write;
--echo # 
connection default;
--echo # Attempt to acquire SR should be blocked. It should
--echo # not cause errors as it does not creates deadlock.
--echo # Sending:
--send select count(*) from t2;
--echo # 
connection mdl_con1;
--echo # Check that the above SELECT is blocked 
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "select count(*) from t2";
--source include/wait_condition.inc
--echo # Unblock SELECT.
unlock tables;
--echo # 
connection default;
--echo # Reap SELECT.
--reap
commit;
--echo # Repeat the same test for SW lock.
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
lock table t2 write;
--echo # 
connection default;
--echo # Again attempt to acquire SW should be blocked and should
--echo # not cause any errors.
--echo # Sending:
--send delete from t2 limit 1;
--echo # 
connection mdl_con1;
--echo # Check that the above DELETE is blocked 
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "delete from t2 limit 1";
--source include/wait_condition.inc
--echo # Unblock DELETE.
unlock tables;
--echo # 
connection default;
--echo # Reap DELETE.
--reap
commit;
--echo #
--echo # Now coverage for the case in which we are acquiring lock on
--echo # the table which is already used in transaction and against
--echo # which there is a pending SNRW lock request.
--echo #
--echo # *) Let us start with case when transaction has only a SR lock.
--echo #
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
--echo # Sending:
--send lock table t1 write;
--echo # 
connection default;
--echo # Wait until LOCK TABLE is blocked creating pending request for X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Check that another instance of SR lock is granted without waiting.
select count(*) from t1;
--echo # Attempt to wait for SW lock will lead to deadlock, thus
--echo # the below statement should end with ER_LOCK_DEADLOCK error.
--error ER_LOCK_DEADLOCK
delete from t1 limit 1;
--echo # Unblock LOCK TABLES.
commit;
--echo # 
connection mdl_con1;
--echo # Reap LOCK TABLES.
--reap
unlock tables;
--echo # 
connection default;
--echo #
--echo # **) Now case when transaction has a SW lock.
--echo #
begin;
delete from t1 limit 1;
--echo # 
connection mdl_con1;
--echo # Sending:
--send lock table t1 write;
--echo # 
connection default;
--echo # Wait until LOCK TABLE is blocked creating pending request for X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "lock table t1 write";
--source include/wait_condition.inc
--echo # Check that both SR and SW locks are granted without waiting
--echo # and errors.
select count(*) from t1;
insert into t1 values (1, 1);
--echo # Unblock LOCK TABLES.
commit;
--echo # 
connection mdl_con1;
--echo # Reap LOCK TABLES.
--reap
unlock tables;
--echo # 
connection default;
--echo #
--echo # 4) Check how various locks used within transactional context
--echo #    interact with active/pending X lock.
--echo # 
--echo #    As usual we start with case when we are acquiring lock on
--echo #    the table which was not used in the transaction before.
begin;
select count(*) from t1;
--echo # 
connection mdl_con2;
--echo # Start transaction which will prevent X lock from going away
--echo # immediately.
begin;
select count(*) from t2;
--echo # 
connection mdl_con1;
--echo # Create pending X lock on t2.
--echo # Sending:
--send rename table t2 to t3;
--echo # 
connection default;
--echo # Wait until RENAME TABLE starts waiting with pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t2 to t3";
--source include/wait_condition.inc
--echo # Check that attempt to acquire SR lock on t2 causes waiting.
--echo # Sending:
--send select count(*) from t2;
--echo # 
connection mdl_con2;
--echo # Check that the above SELECT is blocked.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "select count(*) from t2";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reap RENAME TABLE.
--reap
--echo # 
connection default;
--echo # Reap SELECT.
--error ER_NO_SUCH_TABLE
--reap
commit;
rename table t3 to t2;
--echo # The same test for SW lock.
begin;
select count(*) from t1;
--echo # 
connection mdl_con2;
--echo # Start transaction which will prevent X lock from going away
--echo # immediately.
begin;
select count(*) from t2;
--echo # 
connection mdl_con1;
--echo # Create pending X lock on t2.
--echo # Sending:
--send rename table t2 to t3;
--echo # 
connection default;
--echo # Wait until RENAME TABLE starts waiting with pending X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t2 to t3";
--source include/wait_condition.inc
--echo # Check that attempt to acquire SW lock on t2 causes waiting.
--echo # Sending:
--send delete from t2 limit 1;
--echo # 
connection mdl_con2;
--echo # Check that the above DELETE is blocked.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "delete from t2 limit 1";
--source include/wait_condition.inc
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reap RENAME TABLE.
--reap
--echo # 
connection default;
--echo # Reap DELETE.
--error ER_NO_SUCH_TABLE
--reap
commit;
rename table t3 to t2;
--echo #
--echo # Coverage for the case in which we are acquiring lock on
--echo # the table which is already used in transaction and against
--echo # which there is a pending X lock request.
--echo #
--echo # *) The first case is when transaction has only a SR lock.
--echo #
begin;
select count(*) from t1;
--echo # 
connection mdl_con1;
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection default;
--echo # Wait until RENAME TABLE is blocked creating pending request for X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that another instance of SR lock is granted without waiting.
select count(*) from t1;
--echo # Attempt to wait for SW lock will lead to deadlock, thus
--echo # the below statement should end with ER_LOCK_DEADLOCK error.
--error ER_LOCK_DEADLOCK
delete from t1 limit 1;
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reap RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection default;
--echo #
--echo # **) The second case is when transaction has a SW lock.
--echo #
begin;
delete from t1 limit 1;
--echo # 
connection mdl_con1;
--echo # Sending:
--send rename table t1 to t2;
--echo # 
connection default;
--echo # Wait until RENAME TABLE is blocked creating pending request for X lock.
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
      info = "rename table t1 to t2";
--source include/wait_condition.inc
--echo # Check that both SR and SW locks are granted without waiting
--echo # and errors.
select count(*) from t1;
insert into t1 values (1, 1);
--echo # Unblock RENAME TABLE.
commit;
--echo # 
connection mdl_con1;
--echo # Reap RENAME TABLE.
--error ER_TABLE_EXISTS_ERROR
--reap
--echo # 
connection default;

--echo # Clean-up.
disconnect mdl_con1;
disconnect mdl_con2;
disconnect mdl_con3;
set debug_sync= 'RESET';
drop table t1, t2;

--echo #
--echo # Test coverage for basic deadlock detection in metadata
--echo # locking subsystem.
--echo #
--disable_warnings
drop tables if exists t0, t1, t2, t3, t4, t5;
--enable_warnings
set debug_sync= 'RESET';

connect(deadlock_con1,localhost,root,,);
connect(deadlock_con2,localhost,root,,);
connect(deadlock_con3,localhost,root,,);
connection default;
create table t1 (i int);
create table t2 (j int);
create table t3 (k int);
create table t4 (k int);

--echo #
--echo # Test for the case in which no deadlock occurs.
--echo #

--echo #
connection deadlock_con1;
begin;
insert into t1 values (1);

--echo #
connection deadlock_con2;
begin;
insert into t2 values (1);

--echo #
connection default;
--echo # Send:
--send rename table t2 to t0, t3 to t2, t0 to t3;

--echo #
connection deadlock_con1;
--echo # Wait until the above RENAME TABLE is blocked because it has to wait
--echo # for 'deadlock_con2' which holds shared metadata lock on 't2'.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t2 to t0, t3 to t2, t0 to t3";
--source include/wait_condition.inc
--echo # The below statement should wait for exclusive metadata lock
--echo # on 't2' to go away and should not produce ER_LOCK_DEADLOCK
--echo # as no deadlock is possible in this situation.
--echo # Send:
--send select * from t2;

--echo #
connection deadlock_con2;
--echo # Wait until the above SELECT * FROM t2 is starts waiting
--echo # for an exclusive metadata lock to go away.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "select * from t2";
--source include/wait_condition.inc
--echo #
--echo # Unblock RENAME TABLE by releasing shared metadata lock on t2.
commit;

--echo #
connection default;
--echo # Reap RENAME TABLE.
--reap

--echo #
connection deadlock_con1;
--echo # Reap SELECT.
--reap

--echo #
connection default;
--echo #
--echo # Let us check that in the process of waiting for conflicting lock
--echo # on table 't2' to go away transaction in connection 'deadlock_con1'
--echo # has not released metadata lock on table 't1'.
--echo # Send:
--send rename table t1 to t0, t3 to t1, t0 to t3;

--echo #
connection deadlock_con1;
--echo # Wait until the above RENAME TABLE is blocked because it has to wait
--echo # for 'deadlock_con1' which should still hold shared metadata lock on
--echo # table 't1'.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t1 to t0, t3 to t1, t0 to t3";
--source include/wait_condition.inc
--echo # Commit transaction to unblock RENAME TABLE.
commit;

--echo #
connection default;
--echo # Reap RENAME TABLE.
--reap

--echo #
--echo # Test for case when deadlock occurs and should be detected immediately.
--echo #

--echo #
connection deadlock_con1;
begin;
insert into t2 values (2);

--echo #
connection default;
--echo # Send:
--send rename table t2 to t0, t1 to t2, t0 to t1;

--echo #
connection deadlock_con1;
--echo # Wait until the above RENAME TABLE is blocked because it has to wait
--echo # for 'deadlock_con1' which holds shared metadata lock on 't2'.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t2 to t0, t1 to t2, t0 to t1";
--source include/wait_condition.inc
--echo # 
--echo # The below statement should not wait as doing so will cause deadlock.
--echo # Instead it should fail and emit ER_LOCK_DEADLOCK statement and 
--echo # transaction should be rolled back.
--error ER_LOCK_DEADLOCK
select * from t1;

--echo #
connection default;
--echo # Reap RENAME TABLE.
--reap

--echo #
--echo # Test for the case in which deadlock also occurs but not immediately.
--echo #

--echo #
connection deadlock_con1;
begin;
insert into t2 values (1);

--echo #
connection default;
lock table t1 write;

--echo #
connection deadlock_con1;
--echo # The below SELECT statement should wait for metadata lock
--echo # on table 't1' and should not produce ER_LOCK_DEADLOCK
--echo # immediately as no deadlock is possible at the moment.
--send select * from t1;

--echo #
connection deadlock_con2;
--echo # Wait until the above SELECT * FROM t1 is starts waiting
--echo # for an UNRW metadata lock to go away.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and info = "select * from t1";
--source include/wait_condition.inc

--echo # Send RENAME TABLE statement that will deadlock with the
--echo # SELECT statement and thus should abort the latter.
--send rename table t1 to t0, t2 to t1, t0 to t2;

--echo #
connection default;
--echo # Wait till above RENAME TABLE is blocked while holding
--echo # pending X lock on t1.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "rename table t1 to t0, t2 to t1, t0 to t2";
--source include/wait_condition.inc
--echo # Allow the above RENAME TABLE to acquire lock on t1 and
--echo # create pending lock on t2 thus creating deadlock.
unlock tables;

--echo #
connection deadlock_con1;
--echo # Since the latest RENAME TABLE entered in deadlock with SELECT
--echo # statement the latter should be aborted and emit ER_LOCK_DEADLOCK
--echo # error and transaction should be rolled back.
--echo # Reap SELECT * FROM t1.
--error ER_LOCK_DEADLOCK
--reap

--echo #
connection deadlock_con2;
--echo # Reap RENAME TABLE ... .
--reap;

--echo #
connection default;

drop tables t1, t2, t3, t4;

--echo #
--echo # Now, test case which shows that deadlock detection empiric
--echo # also takes into account requests for metadata lock upgrade.
--echo #
create table t1 (i int);
insert into t1 values (1);
--echo # Avoid race which occurs when SELECT in 'deadlock_con1' connection
--echo # accesses table before the above INSERT unlocks the table and thus
--echo # its result becomes visible to other connections.
select * from t1;

--echo #
connection deadlock_con1;
begin;
select * from t1;

--echo #
connection default;
--echo # Send:
--send alter table t1 add column j int, rename to t2;

--echo #
connection deadlock_con1;
--echo # Wait until the above ALTER TABLE ... RENAME acquires exclusive
--echo # metadata lock on 't2' and starts waiting for connection
--echo # 'deadlock_con1' which holds shared lock on 't1'.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 add column j int, rename to t2";
--source include/wait_condition.inc

--echo # The below statement should not wait as it will cause deadlock.
--echo # An appropriate error should be reported instead and transaction
--echo # should be rolled back.
--error ER_LOCK_DEADLOCK
select * from t2;

--echo #
connection default;
--echo # Reap ALTER TABLE ... RENAME.
--reap

drop table t2;

--echo #
--echo # Test that in situation when MDL subsystem detects a deadlock
--echo # but it turns out that it can be resolved by backing-off locks
--echo # acquired by one of participating transactions (which is
--echo # possible when one of transactions consists only of currently
--echo # executed statement, e.g. in autocommit mode) no error is
--echo # reported.
--echo #
create table t1 (i int);
create table t2 (j int);
--echo # Ensure that the below SELECT stops once it has acquired metadata
--echo # lock on table 't2'.
set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish';
--echo # Sending:
--send select * from t2, t1

--echo #
connection deadlock_con1;
--echo # Wait till SELECT acquires MDL on 't2' and starts waiting for signal.
set debug_sync= 'now WAIT_FOR locked';
--echo # Sending:
--send lock tables t1 write, t2 write

--echo #
connection deadlock_con2;
--echo # Wait until LOCK TABLES acquires SNRW lock on 't1' and is blocked
--echo # while trying to acquire SNRW lock on 't1'.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "lock tables t1 write, t2 write";
--source include/wait_condition.inc
--echo # Resume SELECT execution, this should eventually unblock LOCK TABLES.
set debug_sync= 'now SIGNAL finish';

--echo #
connection deadlock_con1;
--echo # Reaping LOCK TABLES.
--reap
unlock tables;

--echo #
connection default;
--echo # Reaping SELECT. It succeed and not report ER_LOCK_DEADLOCK error.
--reap

drop tables t1, t2;

--echo #
--echo # Test coverage for situation in which a race has happened
--echo # during deadlock detection process which led to unwarranted
--echo # ER_LOCK_DEADLOCK error.
--echo #
create table t1 (i int);

--echo # Ensure that ALTER waits once it has acquired SNW lock.
set debug_sync='alter_table_copy_after_lock_upgrade SIGNAL parked1 WAIT_FOR go1';
--echo # Sending:
--send alter table t1 add column j int

--echo #
connection deadlock_con1;
--echo # Wait till ALTER acquires SNW lock and stops.
set debug_sync='now WAIT_FOR parked1';
--echo # Ensure that INSERT is paused once it detects that there is
--echo # a conflicting metadata lock so it has to wait, but before
--echo # deadlock detection is run.
set debug_sync='mdl_acquire_lock_wait SIGNAL parked2 WAIT_FOR go2';
--echo # Sending:
--send insert into t1 values ()

--echo #
connection deadlock_con2;
--echo # Wait till INSERT is paused.
set debug_sync='now WAIT_FOR parked2';
--echo # Resume ALTER execution. Eventually it will release its
--echo # metadata lock and INSERT's request for SW lock will be
--echo # satisified.
set debug_sync='now SIGNAL go1';

--echo #
connection default;
--echo # Reaping ALTER TABLE.
--reap
--echo # Add a new request for SNW lock to waiting graph.
--echo # Sending:
--send alter table t1 drop column j

--echo #
connection deadlock_con2;
--echo # Wait until ALTER is blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "alter table t1 drop column j";
--source include/wait_condition.inc
--echo # Resume INSERT so it can start deadlock detection.
--echo #
--echo # At this point there is a discrepancy between the fact that INSERT's
--echo # SW lock is already satisfied, but INSERT's connection is still
--echo # marked as waiting for it. Looking for a loop in waiters graph
--echo # without additional checks has detected a deadlock (INSERT waits
--echo # for SW lock; which is not granted because of pending SNW lock from
--echo # ALTER; which waits for active SW lock from INSERT). Since requests
--echo # for SW and SNW locks have same weight ALTER was selected as a victim
--echo # and ended with ER_LOCK_DEADLOCK error.
set debug_sync='now SIGNAL go2';

--echo #
connection deadlock_con1;
--echo # Reaping INSERT.
--reap

--echo #
connection default;
--echo # Reaping ALTER. It should succeed and not produce ER_LOCK_DEADLOCK.
--reap

drop table t1;

--echo #
--echo # Now, test for a situation in which deadlock involves waiting not
--echo # only in MDL subsystem but also for TDC. Such deadlocks should be
--echo # successfully detected. If possible, they should be resolved without
--echo # resorting to ER_LOCK_DEADLOCK error.
--echo #
create table t1(i int);
create table t2(j int);

--echo #
--echo # First, let us check how we handle a simple scenario involving
--echo # waits in MDL and TDC.
--echo #
set debug_sync= 'RESET';

connection deadlock_con1;
--echo # Start a statement, which will acquire SR metadata lock on t1, open it
--echo # and then stop, before trying to acquire SW lock on t2 and opening it.
set debug_sync='open_tables_after_open_and_process_table SIGNAL parked WAIT_FOR go';
--echo # Sending:
--send select * from t1 where i in (select j from t2 for update)

connection deadlock_con2;
--echo # Wait till the above SELECT stops.
set debug_sync='now WAIT_FOR parked';
--echo # The below FLUSH TABLES WITH READ LOCK should acquire
--echo # SNW locks on t1 and t2 and wait till SELECT closes t1.
--echo # Sending:
send flush tables t1, t2 with read lock;

connection deadlock_con3;
--echo # Wait until FLUSH TABLES WITH t1, t2 READ LOCK starts waiting
--echo # for SELECT to close t1.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table flush" and
        info = "flush tables t1, t2 with read lock";
--source include/wait_condition.inc

--echo # Resume SELECT, so it tries to acquire SW lock on t1 and blocks,
--echo # creating a deadlock. This deadlock should be detected and resolved
--echo # by backing-off SELECT. As a result FTWRL should be able to finish.
set debug_sync='now SIGNAL go';

connection deadlock_con2;
--echo # Reap FLUSH TABLES WITH READ LOCK.
reap;
unlock tables;

connection deadlock_con1;
--echo # Reap SELECT.
reap;

--echo #
--echo # The same scenario with a slightly different order of events
--echo # which emphasizes that setting correct deadlock detector weights
--echo # for flush waits is important.
--echo #
set debug_sync= 'RESET';

connection deadlock_con2;
set debug_sync='flush_tables_with_read_lock_after_acquire_locks SIGNAL parked WAIT_FOR go';

--echo # The below FLUSH TABLES WITH READ LOCK should acquire
--echo # SNW locks on t1 and t2 and wait on debug sync point.
--echo # Sending:
send flush tables t1, t2 with read lock;

connection deadlock_con1;
--echo # Wait till FLUSH TABLE WITH READ LOCK stops.
set debug_sync='now WAIT_FOR parked';

--echo # Start statement which will acquire SR metadata lock on t1, open
--echo # it and then will block while trying to acquire SW lock on t2.
--echo # Sending:
send select * from t1 where i in (select j from t2 for update);

connection deadlock_con3;
--echo # Wait till the above SELECT blocks.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "select * from t1 where i in (select j from t2 for update)";
--source include/wait_condition.inc

--echo # Resume FLUSH TABLES, so it tries to flush t1, thus creating
--echo # a deadlock. This deadlock should be detected and resolved by
--echo # backing-off SELECT. As a result FTWRL should be able to finish.
set debug_sync='now SIGNAL go';

connection deadlock_con2;
--echo # Reap FLUSH TABLES WITH READ LOCK.
reap;
unlock tables;

connection deadlock_con1;
--echo # Reap SELECT.
reap;

--echo #
--echo # Now a more complex scenario involving two connections
--echo # waiting for MDL and one for TDC.
--echo #
set debug_sync= 'RESET';

connection deadlock_con1;
--echo # Start a statement which will acquire SR metadata lock on t2, open it
--echo # and then stop, before trying to acquire SR on t1 and opening it.
set debug_sync='open_tables_after_open_and_process_table SIGNAL parked WAIT_FOR go';
--echo # Sending:
send select * from t2, t1;

connection deadlock_con2;
--echo # Wait till the above SELECT stops.
set debug_sync='now WAIT_FOR parked';
--echo # The below FLUSH TABLES WITH READ LOCK should acquire
--echo # SNW locks on t2 and wait till SELECT closes t2.
--echo # Sending:
send flush tables t2 with read lock;

connection deadlock_con3;
--echo # Wait until FLUSH TABLES WITH READ LOCK starts waiting
--echo # for SELECT to close t2.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table flush" and
        info = "flush tables t2 with read lock";
--source include/wait_condition.inc

--echo # The below DROP TABLES should acquire X lock on t1 and start
--echo # waiting for X lock on t2.
--echo # Sending:
send drop tables t1, t2;

connection default;
--echo # Wait until DROP TABLES starts waiting for X lock on t2.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "drop tables t1, t2";
--source include/wait_condition.inc

--echo # Resume SELECT, so it tries to acquire SR lock on t1 and blocks,
--echo # creating a deadlock. This deadlock should be detected and resolved
--echo # by backing-off SELECT. As a result, FTWRL should be able to finish.
set debug_sync='now SIGNAL go';

connection deadlock_con2;
--echo # Reap FLUSH TABLES WITH READ LOCK.
reap;
--echo # Unblock DROP TABLES.
unlock tables;

connection deadlock_con3;
--echo # Reap DROP TABLES.
reap;

connection deadlock_con1;
--echo # Reap SELECT. It should emit error about missing table.
--error ER_NO_SUCH_TABLE
reap;

connection default;

set debug_sync= 'RESET';

disconnect deadlock_con1;
disconnect deadlock_con2;
disconnect deadlock_con3;


--echo #
--echo # Test for a scenario in which FLUSH TABLES <list> WITH READ LOCK
--echo # used to erroneously release metadata locks.
--echo # 
connect(con1,localhost,root,,);
connect(con2,localhost,root,,);
connection default;
--disable_warnings
drop tables if exists t1, t2;
--enable_warnings
set debug_sync= 'RESET';
create table t1(i int);
create table t2(j int);

connection con2;
set debug_sync='open_tables_after_open_and_process_table SIGNAL parked WAIT_FOR go';

--echo # The below FLUSH TABLES <list> WITH READ LOCK should acquire
--echo # SNW locks on t1 and t2, open table t1 and block on the debug
--echo # sync point.
--echo # Sending:
send flush tables t1, t2 with read lock;

connection con1;
--echo # Wait till FLUSH TABLES <list> WITH READ LOCK stops.
set debug_sync='now WAIT_FOR parked';

--echo # Start a statement which will flush all tables and thus
--echo # invalidate table t1 open by FLUSH TABLES <list> WITH READ LOCK.
--echo # Sending:
send flush tables;

connection default;
--echo # Wait till the above FLUSH TABLES blocks.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table flush" and
        info = "flush tables";
--source include/wait_condition.inc

--echo # Resume FLUSH TABLES <list> WITH READ LOCK, so it tries to open t2
--echo # discovers that its t1 is obsolete and tries to reopen all tables.
--echo # Such reopen should not cause releasing of SNW metadata locks
--echo # which would result in assertion failures.
set debug_sync='now SIGNAL go';

connection con2;
--echo # Reap FLUSH TABLES <list> WITH READ LOCK.
reap;
unlock tables;

connection con1;
--echo # Reap FLUSH TABLES.
reap;

--echo # Clean-up.
connection default;
drop tables t1, t2;
set debug_sync= 'RESET';
disconnect con1;
disconnect con2;


--echo #
--echo # Test for bug #46748 "Assertion in MDL_context::wait_for_locks()
--echo # on INSERT + CREATE TRIGGER".
--echo #
--disable_warnings
drop tables if exists t1, t2, t3, t4, t5;
--enable_warnings
--echo # Let us simulate scenario in which we open some tables from extended
--echo # part of prelocking set but then encounter conflicting metadata lock,
--echo # so have to back-off and wait for it to go away.
connect (con1root,localhost,root,,test,,);
connect (con2root,localhost,root,,test,,);
connection default;
create table t1 (i int);
create table t2 (j int);
create table t3 (k int);
create table t4 (l int);
create trigger t1_bi before insert on t1 for each row
  insert into t2 values (new.i);
create trigger t2_bi before insert on t2 for each row
  insert into t3 values (new.j);
--echo #
connection con1root;
lock tables t4 read;
--echo #
connection con2root;
--echo # Send :
--send rename table t3 to t5, t4 to t3;
--echo #
connection default;
--echo # Wait until the above RENAME TABLE adds pending requests for exclusive
--echo # metadata lock on its tables and blocks due to 't4' being used by LOCK
--echo # TABLES.
let $wait_condition= select count(*)= 1 from information_schema.processlist
                       where state= 'Waiting for table metadata lock' and
                             info='rename table t3 to t5, t4 to t3';
--source include/wait_condition.inc
--echo # Send :
--send insert into t1 values (1);
--echo #
connection con1root;
--echo # Wait until INSERT statement waits due to encountering pending
--echo # exclusive metadata lock on 't3'.
let $wait_condition= select count(*)= 1 from information_schema.processlist
                       where state= 'Waiting for table metadata lock' and
                             info='insert into t1 values (1)';
--source include/wait_condition.inc
unlock tables;
--echo #
connection con2root;
--echo # Reap RENAME TABLE.
--reap
--echo #
connection default;
--echo # Reap INSERT.
--reap
--echo # Clean-up.
disconnect con1root;
disconnect con2root;
drop tables t1, t2, t3, t5;


--echo #
--echo # Bug#42546 - Backup: RESTORE fails, thinking it finds an existing table
--echo #

--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings
set @save_log_output=@@global.log_output;
set global log_output=file;

connect(con2, localhost, root,,);

--echo #
--echo # Test 1: CREATE TABLE
--echo #

connection con2;
--echo # Start insert on the not-yet existing table
--echo # Wait after taking the MDL lock
SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish';
--send INSERT INTO t1 VALUES(1,"def")

connection default;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Now INSERT has a MDL on the non-existent table t1.

--echo #
--echo # Continue the INSERT once CREATE waits for exclusive lock
SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL finish';
--echo # Try to create that table.
--send CREATE TABLE t1 (c1 INT, c2 VARCHAR(100), KEY(c1))

--echo # Insert fails
connection con2;
--error ER_NO_SUCH_TABLE
--reap

connection default;
--reap;
SET DEBUG_SYNC= 'RESET';
SHOW TABLES;

--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings

--echo #
--echo # Test 2: CREATE TABLE LIKE
--echo #

CREATE TABLE t2 (c1 INT, c2 VARCHAR(100), KEY(c1));

connection con2;
--echo # Start insert on the not-yet existing table
--echo # Wait after taking the MDL
SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish';
--send INSERT INTO t1 VALUES(1,"def")

connection default;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Now INSERT has a MDL on the non-existent table t1.

--echo #
--echo # Continue the INSERT once CREATE waits for exclusive lock
SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL finish';
--echo # Try to create that table.
--send CREATE TABLE t1 LIKE t2

--echo # Insert fails
connection con2;
--error ER_NO_SUCH_TABLE
--reap

connection default;
--reap
SET DEBUG_SYNC= 'RESET';
SHOW TABLES;

DROP TABLE t2;
disconnect con2;
--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings

set global log_output=@save_log_output;


--echo #
--echo # Bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE HIGH_PRIORITY
--echo #             FOR UPDATE"
--echo #
--disable_warnings
drop tables if exists t1, t2;
--enable_warnings
connect (con46044, localhost, root,,);
connect (con46044_2, localhost, root,,);
connect (con46044_3, localhost, root,,);
connection default;
create table t1 (i int);
insert into t1 values(1);

--echo # Let us check that we won't deadlock if during filling
--echo # of I_S table we encounter conflicting metadata lock
--echo # which owner is in its turn waiting for our connection.
lock tables t1 read;

connection con46044_2;
--echo # Sending:
--send update t1 set i = 2

connection con46044;

--echo # Waiting until UPDATE t1 SET ... is blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table level lock" and
        info = "update t1 set i = 2";
--source include/wait_condition.inc

--echo # Sending:
--send create table t2 select * from t1;

connection default;
--echo # Waiting until CREATE TABLE ... SELECT ... is blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table level lock" and
        info = "create table t2 select * from t1";
--source include/wait_condition.inc

--echo # First let us check that SHOW FIELDS/DESCRIBE doesn't
--echo # gets blocked and emits and error.
--error ER_WARN_I_S_SKIPPED_TABLE
show fields from t2;

--echo # Now test for I_S query which reads only .FRMs.
--echo #
--echo # Query below should only emit a warning.
select column_name from information_schema.columns
  where table_schema='test' and table_name='t2';

--echo # Finally, test for I_S query which does full-blown table open.
--echo #
--echo # Query below should not be blocked. Warning message should be
--echo # stored in the 'table_comment' column.
select table_name, table_type, auto_increment, table_comment
  from information_schema.tables where table_schema='test' and table_name='t2';

connection default;
unlock tables;

connection con46044;
--echo # Reaping CREATE TABLE ... SELECT ... .
--reap
drop table t2;

connection con46044_2;
--echo # Reaping UPDATE t1 statement
--reap

--echo #
--echo # Let us also check that queries to I_S wait for conflicting metadata
--echo # locks to go away instead of skipping table with a warning in cases
--echo # when deadlock is not possible. This is a nice thing from compatibility
--echo # and ease of use points of view.
--echo #
--echo # We check same three queries to I_S in this new situation.

connection con46044_2;
lock tables t1 read;

connection con46044_3;
--echo # Sending:
send update t1 set i = 3;

connection con46044;

--echo # Waiting until UPDATE t1 SET ... is blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table level lock" and
        info = "update t1 set i = 3";
--source include/wait_condition.inc

--echo # Sending:
--send create table t2 select * from t1;

connection default;
--echo # Waiting until CREATE TABLE ... SELECT ... is blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table level lock" and
        info = "create table t2 select * from t1";
--source include/wait_condition.inc

--echo # Let us check that SHOW FIELDS/DESCRIBE gets blocked.
--echo # Sending:
--send show fields from t2;

connection con46044_2;
--echo # Wait until SHOW FIELDS gets blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "show fields from t2";
--source include/wait_condition.inc

unlock tables;

connection con46044;
--echo # Reaping CREATE TABLE ... SELECT ... .
--reap

connection default;
--echo # Reaping SHOW FIELDS ...
--reap
drop table t2;

connection con46044_3;
--echo # Reaping UPDATE t1 statement
--reap

connection con46044_2;
lock tables t1 read;

connection con46044_3;
--echo # Sending:
--send update t1 set i = 4

connection con46044;

--echo # Waiting until UPDATE t1 SET ... is blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table level lock" and
        info = "update t1 set i = 4";
--source include/wait_condition.inc

--echo # Sending:
--send create table t2 select * from t1;

connection default;
--echo # Waiting until CREATE TABLE ... SELECT ... is blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table level lock" and
        info = "create table t2 select * from t1";
--source include/wait_condition.inc

--echo # Check that I_S query which reads only .FRMs gets blocked.
--echo # Sending:
--send select column_name from information_schema.columns where table_schema='test' and table_name='t2';

connection con46044_2;
--echo # Wait until SELECT COLUMN_NAME FROM I_S.COLUMNS  gets blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info like "select column_name from information_schema.columns%";
--source include/wait_condition.inc

unlock tables;

connection con46044;
--echo # Reaping CREATE TABLE ... SELECT ... .
--reap

connection default;
--echo # Reaping SELECT COLUMN_NAME FROM I_S.COLUMNS
--reap
drop table t2;

connection con46044_3;
--echo # Reaping UPDATE t1 statement
--reap

connection con46044_2;
lock tables t1 read;

connection con46044_3;
--echo # Sending:
--send update t1 set i = 5

connection con46044;

--echo # Waiting until UPDATE t1 SET ... is blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table level lock" and
        info = "update t1 set i = 5";
--source include/wait_condition.inc

--echo # Sending:
--send create table t2 select * from t1;

connection default;
--echo # Waiting until CREATE TABLE ... SELECT ... is blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table level lock" and
        info = "create table t2 select * from t1";
--source include/wait_condition.inc

--echo # Finally, check that I_S query which does full-blown table open
--echo # also gets blocked.
--echo # Sending:
--send select table_name, table_type, auto_increment, table_comment from information_schema.tables where table_schema='test' and table_name='t2';

connection con46044_2;
--echo # Wait until SELECT ... FROM I_S.TABLES gets blocked.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info like "select table_name, table_type, auto_increment, table_comment from information_schema.tables%";
--source include/wait_condition.inc

unlock tables;

connection con46044;
--echo # Reaping CREATE TABLE ... SELECT ... .
--reap

connection default;
--echo # Reaping SELECT ... FROM I_S.TABLES
--reap
drop table t2;

connection con46044_3;
--echo # Reaping UPDATE t1 statement
--reap

connection default;
--echo # Clean-up.
disconnect con46044;
disconnect con46044_2;
disconnect con46044_3;
drop table t1;


--echo #
--echo # Test for bug #46273 "MySQL 5.4.4 new MDL: Bug#989 is not fully fixed
--echo #                      in case of ALTER".
--echo #
--disable_warnings
drop table if exists t1;
--enable_warnings
set debug_sync= 'RESET';
connect (con46273,localhost,root,,test,,);
connection default;
create table t1 (c1 int primary key, c2 int, c3 int);
insert into t1 values (1,1,0),(2,2,0),(3,3,0),(4,4,0),(5,5,0);

begin;
select * from t1 where c2 = 3;

--echo #
connection con46273;
set debug_sync='alter_table_copy_after_lock_upgrade SIGNAL alter_table_locked WAIT_FOR alter_go';
--send alter table t1 add column e int, rename to t2;

--echo #
connection default;
set debug_sync='now WAIT_FOR alter_table_locked';
set debug_sync='mdl_acquire_lock_wait SIGNAL alter_go';
--echo # The below statement should get ER_LOCK_DEADLOCK error
--echo # (i.e. it should not allow ALTER to proceed, and then
--echo # fail due to 't1' changing its name to 't2').
--error ER_LOCK_DEADLOCK
update t1 set c3=c3+1 where c2 = 3;

--echo #
connection con46273;
--echo # Reap ALTER TABLE.
--reap

--echo #
connection default;
disconnect con46273;
--echo # Clean-up.
set debug_sync= 'RESET';
drop table t2;


--echo #
--echo # Test for bug #46673 "Deadlock between FLUSH TABLES WITH READ LOCK
--echo #                      and DML".
--echo #
--disable_warnings
drop tables if exists t1;
--enable_warnings
connect (con46673, localhost, root,,);
connection default;
create table t1 (i int);

connection con46673;
begin;
insert into t1 values (1);

connection default;
--echo # Statement below should not get blocked. And if after some
--echo # changes to code it is there should not be a deadlock between
--echo # it and transaction from connection 'con46673'.
flush tables with read lock;
unlock tables;

connection con46673;
delete from t1 where i = 1;
commit;

connection default;
--echo # Clean-up
disconnect con46673;
drop table t1;


--echo #
--echo # Bug#48210 FLUSH TABLES WITH READ LOCK deadlocks 
--echo #           against concurrent CREATE PROCEDURE
--echo #

connect (con2, localhost, root);

--echo # Test 1: CREATE PROCEDURE

connection default;
--echo # Start CREATE PROCEDURE and open mysql.proc
SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL table_opened WAIT_FOR grlwait';
--send CREATE PROCEDURE p1() SELECT 1

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR table_opened';
--echo # Check that FLUSH must wait to get the GRL
--echo # and let CREATE PROCEDURE continue
SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL grlwait';
--send FLUSH TABLES WITH READ LOCK

connection default;
--reap

connection con2;
--reap
UNLOCK TABLES;

connection default;
SET DEBUG_SYNC= 'RESET';

--echo # Test 2: DROP PROCEDURE

connection default;
--echo # Start DROP PROCEDURE and open tables
SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL table_opened WAIT_FOR grlwait';
--send DROP PROCEDURE p1

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR table_opened';
--echo # Check that FLUSH must wait to get the GRL
--echo # and let DROP PROCEDURE continue
SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL grlwait';
--send FLUSH TABLES WITH READ LOCK

connection default;
--echo # Once FLUSH TABLES WITH READ LOCK starts waiting
--echo # DROP PROCEDURE will be waked up and will drop
--echo # procedure. Global read lock will be granted after
--echo # this statement ends.
--echo #
--echo # Reaping DROP PROCEDURE.
--reap

connection con2;
--echo # Reaping FTWRL.
--reap
UNLOCK TABLES;

connection default;
SET DEBUG_SYNC= 'RESET';

disconnect con2;


--echo #
--echo # Bug#50786 Assertion `thd->mdl_context.trans_sentinel() == __null' 
--echo #           failed in open_ltable()
--echo #

--echo # Supress warnings written to the log file
call mtr.add_suppression("Wait on a lock was aborted due to a pending exclusive lock");
--disable_warnings
DROP TABLE IF EXISTS t1, t2;
--enable_warnings

connect (con1,localhost,root);
connect (con2,localhost,root);
connect (con3,localhost,root);
connection default;

CREATE TABLE t1 (i INT);
CREATE TABLE t2 (i INT);

SET @old_general_log= @@global.general_log;
SET @@global.general_log= 1;

SET @old_log_output= @@global.log_output;
SET @@global.log_output= 'TABLE';

SET @old_sql_log_off= @@session.sql_log_off;
SET @@session.sql_log_off= 1;

--echo # connection: con1
connection con1;
HANDLER t1 OPEN;

--echo # connection: con3
connection con3;
SET @@session.sql_log_off= 1;

--echo # connection: con2
connection con2;
SET DEBUG_SYNC= 'thr_multi_lock_after_thr_lock SIGNAL parked WAIT_FOR go';

# The below statement will block on the debug sync point
# after it gets write lock on mysql.general_log table.
--echo # Sending:
--send SELECT 1

--echo # connection: con3
connection con3;
SET DEBUG_SYNC= 'now WAIT_FOR parked';

--echo # connection: con1
connection con1;
# This statement will block in open_ltable() when
# trying to write into mysql.general_log.
--echo # Sending:
--send SELECT 1

--echo # connection: con3
connection con3;
let $wait_condition=
  SELECT COUNT(*) = 1 FROM information_schema.processlist
  WHERE state = "Waiting for table level lock" and info = "SELECT 1";
--source include/wait_condition.inc
# The ALTER below will try to abort the statement in connection con1,
# since the latter waits on a table-level lock while having a HANDLER
# open. This will cause mysql_lock_tables() in con1 fail which before
# triggered the assert.
ALTER TABLE t1 ADD COLUMN j INT;

--echo # connection: default
connection default;
SET DEBUG_SYNC= 'now SIGNAL go';

--echo # connection: con1
connection con1;
--echo # Reaping SELECT 1
--reap
HANDLER t1 CLOSE;

--echo # connection: con2
connection con2;
--echo # Reaping SELECT 1
--reap

--echo # connection: default
connection default;
DROP TABLE t1, t2;
SET DEBUG_SYNC= 'RESET';
disconnect con1;
disconnect con2;
disconnect con3;
SET @@global.general_log= @old_general_log;
SET @@global.log_output= @old_log_output;
SET @@session.sql_log_off= @old_sql_log_off;


--echo #
--echo # Additional coverage for bug #50913 "Deadlock between
--echo # open_and_lock_tables_derived and MDL". The main test
--echo # case is in lock_multi.test
--echo #
--disable_warnings
drop table if exists t1;
--enable_warnings
set debug_sync= 'RESET';
connect (con50913_1,localhost,root);
connect (con50913_2,localhost,root);
connection default;
create table t1 (i int) engine=InnoDB;

connection con50913_1;
set debug_sync= 'alter_table_copy_after_lock_upgrade SIGNAL parked WAIT_FOR go';
--echo # Sending:
--send alter table t1 add column j int, ALGORITHM=COPY

connection default;
--echo # Wait until ALTER TABLE gets blocked on a sync point after
--echo # acquiring thr_lock.c lock.
set debug_sync= 'now WAIT_FOR parked';
--echo # The below statement should wait on MDL lock and not deadlock on
--echo # thr_lock.c lock.
--echo # Sending:
--send truncate table t1

connection con50913_2;
--echo # Wait until TRUNCATE TABLE is blocked on MDL lock.
let $wait_condition=
  select count(*) = 1 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "truncate table t1";
--source include/wait_condition.inc
--echo # Unblock ALTER TABLE.
set debug_sync= 'now SIGNAL go';

connection con50913_1;
--echo # Reaping ALTER TABLE.
--reap

connection default;
--echo # Reaping TRUNCATE TABLE.
--reap
disconnect con50913_1;
disconnect con50913_2;
set debug_sync= 'RESET';
drop table t1;


--echo #
--echo # Test for bug #50998 "Deadlock in MDL code during test
--echo #                      rqg_mdl_stability".
--echo # Also provides coverage for the case when addition of
--echo # waiting statement adds several loops in the waiters
--echo # graph and therefore several searches for deadlock
--echo # should be performed.
--disable_warnings
drop table if exists t1;
--enable_warnings
set debug_sync= 'RESET';
connect (con1,localhost,root);
connect (con2,localhost,root);
connect (con3,localhost,root);
connection default;
create table t1 (i int);

connection con1;
begin;
select * from t1;

connection con2;
begin;
select * from t1;

connection default;
--echo # Start ALTER TABLE which will acquire SNW lock and
--echo # table lock and get blocked on sync point.
set debug_sync= 'alter_table_copy_after_lock_upgrade SIGNAL parked WAIT_FOR go';
--echo # Sending:
--send alter table t1 add column j int

connection con1;
--echo # Wait until ALTER TABLE gets blocked on a sync point.
set debug_sync= 'now WAIT_FOR parked';
--echo # Sending:
--send insert into t1 values (1)

connection con2;
--echo # Sending:
--send insert into t1 values (1)

connection con3;
--echo # Wait until both 'con1' and 'con2' are blocked trying to acquire
--echo # SW lock on the table.
let $wait_condition=
  select count(*) = 2 from information_schema.processlist
  where state = "Waiting for table metadata lock" and
        info = "insert into t1 values (1)";
--source include/wait_condition.inc
--echo # Unblock ALTER TABLE. Since it will try to upgrade SNW to X lock
--echo # deadlock with two loops in waiting graph will occur. Both loops
--echo # should be found and DML statements in both 'con1' and 'con2'
--echo # should be aborted with ER_LOCK_DEADLOCK errors.
set debug_sync= 'now SIGNAL go';

connection con1;
--echo # Reaping INSERT. It should end with ER_LOCK_DEADLOCK error and
--echo # not wait indefinitely (as it happened before the bugfix).
--error ER_LOCK_DEADLOCK
--reap
commit;

connection con2;
--echo # Reaping INSERT.
--error ER_LOCK_DEADLOCK
--reap
commit;

connection default;
--echo # Reap ALTER TABLE.
--reap

disconnect con1;
disconnect con2;
disconnect con3;
connection default;
set debug_sync= 'RESET';
drop table t1;

--echo #
--echo # Bug#42643: InnoDB does not support replication of TRUNCATE TABLE
--echo #
--echo # Ensure that a acquired lock is not given up due to a conflict.
--echo #

connect (con1,localhost,root,,test,,);
connect (con2,localhost,root,,test,,);
connect (con3,localhost,root,,test,,);

connection default;

--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings

CREATE TABLE t1 (a INT) ENGINE=InnoDB;
INSERT INTO t1 VALUES (1),(2),(3);

connection con1;
LOCK TABLES t1 WRITE;
SET debug_sync='upgrade_lock_for_truncate SIGNAL parked_truncate WAIT_FOR go_truncate';
send TRUNCATE TABLE t1;

connection default;
SET debug_sync='now WAIT_FOR parked_truncate';

connection con2;
SET debug_sync='after_open_table_ignore_flush SIGNAL parked_show WAIT_FOR go_show';
send SHOW FIELDS FROM t1;

connection default;
SET debug_sync='now WAIT_FOR parked_show';

connection con3;
SET debug_sync='after_flush_unlock SIGNAL parked_flush WAIT_FOR go_flush';
send FLUSH TABLES t1;

connection default;
SET debug_sync='now WAIT_FOR parked_flush';
SET debug_sync='now SIGNAL go_truncate';
--echo # Ensure that truncate waits for a exclusive lock
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for table metadata lock' AND info='TRUNCATE TABLE t1';
--source include/wait_condition.inc
SET debug_sync= 'now SIGNAL go_show';

connection con1;
--echo # Reaping...
reap;
UNLOCK TABLES;

connection con2;
--echo # Reaping...
reap;

connection default;
SET debug_sync= 'now SIGNAL go_flush';

connection con3;
--echo # Reaping...
reap;

disconnect con1;
disconnect con2;
disconnect con3;

connection default;
SET debug_sync= 'RESET';
DROP TABLE t1;


--echo #
--echo # Bug#52856 concurrent show columns or show full columns causes a crash!!!
--echo #
CREATE TABLE t1(a CHAR(255));

connect(con1, localhost, root);
SET DEBUG_SYNC= "get_schema_column SIGNAL waiting WAIT_FOR completed";
--send SHOW FULL COLUMNS FROM t1

connection default;
SET DEBUG_SYNC= "now WAIT_FOR waiting";
--replace_column 8 #
SHOW FULL COLUMNS FROM t1;
SET DEBUG_SYNC= "now SIGNAL completed";
--replace_column 8 #
connection con1;
--reap
connection default;
DROP TABLE t1;
disconnect con1;


--echo #
--echo # Tests for schema-scope locks
--echo #

--disable_warnings
DROP DATABASE IF EXISTS db1;
DROP DATABASE IF EXISTS db2;
--enable_warnings

connect (con2, localhost, root);
connect (con3, localhost, root);

--echo # Test 1: 
--echo # CREATE DATABASE blocks database DDL on the same database, but
--echo # not database DDL on different databases. Tests X vs X lock.
--echo #

connection default;
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send CREATE DATABASE db1

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should block.
--send CREATE DATABASE db1

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock' AND info='CREATE DATABASE db1';
--source include/wait_condition.inc
# This should not block.
CREATE DATABASE db2;
ALTER DATABASE db2 DEFAULT CHARACTER SET utf8;
DROP DATABASE db2;
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: CREATE DATABASE db1
--reap

connection con2;
--echo # Reaping: CREATE DATABASE db1
--error ER_DB_CREATE_EXISTS
--reap

--echo # Test 2:
--echo # ALTER DATABASE blocks database DDL on the same database, but
--echo # not database DDL on different databases. Tests X vs X lock.
--echo #

connection default;
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send ALTER DATABASE db1 DEFAULT CHARACTER SET utf8

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should block.
--send ALTER DATABASE db1 DEFAULT CHARACTER SET utf8

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock'
  AND info='ALTER DATABASE db1 DEFAULT CHARACTER SET utf8';
--source include/wait_condition.inc
# This should not block.
CREATE DATABASE db2;
ALTER DATABASE db2 DEFAULT CHARACTER SET utf8;
DROP DATABASE db2;
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8
--reap

connection con2;
--echo # Reaping: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8
--reap

connection default;
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send ALTER DATABASE db1 DEFAULT CHARACTER SET utf8

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should also block.
--send DROP DATABASE db1

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock' AND info='DROP DATABASE db1';
--source include/wait_condition.inc
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8
--reap

connection con2;
--echo # Reaping: DROP DATABASE db1
--reap
# Recreate the database
CREATE DATABASE db1;

--echo # Test 3:
--echo # Two ALTER..UPGRADE of the same database are mutually exclusive, but
--echo # two ALTER..UPGRADE of different databases are not. Tests X vs X lock.
--echo #

let $MYSQLD_DATADIR= `select @@datadir`;
# Manually make a 5.0 database from the template
--mkdir $MYSQLD_DATADIR/a-b-c
--copy_file $MYSQLD_DATADIR/db1/db.opt $MYSQLD_DATADIR/a-b-c/db.opt
--mkdir $MYSQLD_DATADIR/a-b-c-d
--copy_file $MYSQLD_DATADIR/db1/db.opt $MYSQLD_DATADIR/a-b-c-d/db.opt

connection default;
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send ALTER DATABASE `#mysql50#a-b-c` UPGRADE DATA DIRECTORY NAME

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should block.
--send ALTER DATABASE `#mysql50#a-b-c` UPGRADE DATA DIRECTORY NAME

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock'
  AND info='ALTER DATABASE `#mysql50#a-b-c` UPGRADE DATA DIRECTORY NAME';
--source include/wait_condition.inc
# This should not block.
ALTER DATABASE `#mysql50#a-b-c-d` UPGRADE DATA DIRECTORY NAME;
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: ALTER DATABASE '#mysql50#a-b-c' UPGRADE DATA DIRECTORY NAME
--reap

connection con2;
--echo # Reaping: ALTER DATABASE '#mysql50#a-b-c' UPGRADE DATA DIRECTORY NAME
--error ER_BAD_DB_ERROR
--reap
DROP DATABASE `a-b-c`;
DROP DATABASE `a-b-c-d`;

--echo # Test 4:
--echo # DROP DATABASE blocks database DDL on the same database, but
--echo # not database DDL on different databases. Tests X vs X lock.
--echo #

connection default;
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send DROP DATABASE db1

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should block.
--send DROP DATABASE db1

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock' AND info='DROP DATABASE db1';
--source include/wait_condition.inc
# This should not block.
CREATE DATABASE db2;
ALTER DATABASE db2 DEFAULT CHARACTER SET utf8;
DROP DATABASE db2;
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: DROP DATABASE db1
--reap

connection con2;
--echo # Reaping: DROP DATABASE db1
--error ER_DB_DROP_EXISTS
--reap

connection default;
CREATE DATABASE db1;
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send DROP DATABASE db1

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should also block.
--send ALTER DATABASE db1 DEFAULT CHARACTER SET utf8

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock'
  AND info='ALTER DATABASE db1 DEFAULT CHARACTER SET utf8';
--source include/wait_condition.inc
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: DROP DATABASE db1
--reap

connection con2;
--echo # Reaping: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8
# Error 1 is from ALTER DATABASE when the database does not exist.
# Listing the error twice to prevent result diffences based on filename.
--error 1,1
--reap


--echo # Test 5:
--echo # Locked database name prevents CREATE of tables in that database.
--echo # Tests X vs IX lock.
--echo #

connection default;
CREATE DATABASE db1;
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send DROP DATABASE db1

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should block.
--send CREATE TABLE db1.t1 (a INT)

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock' AND
        info='CREATE TABLE db1.t1 (a INT)';
--source include/wait_condition.inc
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: DROP DATABASE db1
--reap

connection con2;
--echo # Reaping: CREATE TABLE db1.t1 (a INT)
--error ER_BAD_DB_ERROR
--reap

--echo # Test 6:
--echo # Locked database name prevents RENAME of tables to/from that database.
--echo # Tests X vs IX lock.
--echo #

connection default;
CREATE DATABASE db1;
CREATE TABLE db1.t1 (a INT);
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send DROP DATABASE db1

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should block.
--send RENAME TABLE db1.t1 TO test.t1

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock' AND
        info='RENAME TABLE db1.t1 TO test.t1';
--source include/wait_condition.inc
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: DROP DATABASE db1
--reap

connection con2;
--echo # Reaping: RENAME TABLE db1.t1 TO test.t1
--error ER_NO_SUCH_TABLE
--reap

connection default;
CREATE DATABASE db1;
CREATE TABLE test.t2 (a INT);
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send DROP DATABASE db1

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should block.
--send RENAME TABLE test.t2 TO db1.t2

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock' AND
        info='RENAME TABLE test.t2 TO db1.t2';
--source include/wait_condition.inc
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: DROP DATABASE db1
--reap

connection con2;
--echo # Reaping: RENAME TABLE test.t2 TO db1.t2
# Error 7 is from RENAME TABLE where the target database does not exist.
# Listing the error twice to prevent result diffences based on filename.
--error 7, 7
--reap
DROP TABLE test.t2;


--echo # Test 7:
--echo # Locked database name prevents DROP of tables in that database.
--echo # Tests X vs IX lock.
--echo #

connection default;
CREATE DATABASE db1;
CREATE TABLE db1.t1 (a INT);
SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked';
--echo # Sending:
--send DROP DATABASE db1

connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR locked';
--echo # Sending:
# This should block.
--send DROP TABLE db1.t1

connection con3;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for schema metadata lock' AND info='DROP TABLE db1.t1';
--source include/wait_condition.inc
SET DEBUG_SYNC= 'now SIGNAL blocked';

connection default;
--echo # Reaping: DROP DATABASE db1
--reap

connection con2;
--echo # Reaping: DROP TABLE db1.t1
--error ER_BAD_TABLE_ERROR
--reap

connection default;
disconnect con2;
disconnect con3;
SET DEBUG_SYNC= 'RESET';

--echo #
--echo # End of tests for schema-scope locks
--echo #

--echo #
--echo # Tests of granted global S lock (FLUSH TABLE WITH READ LOCK)
--echo #

CREATE DATABASE db1;
CREATE TABLE db1.t1(a INT);
connect(con2, localhost, root);
connect(con3, localhost, root);

connection default;
FLUSH TABLE WITH READ LOCK;

connection con2;
# IX global lock should block
--send CREATE TABLE db1.t2(a INT)

connection default;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for global read lock'
  AND info='CREATE TABLE db1.t2(a INT)';
--source include/wait_condition.inc
UNLOCK TABLES;

connection con2;
--echo # Reaping CREATE TABLE db1.t2(a INT)
--reap

connection default;
FLUSH TABLE WITH READ LOCK;

connection con2;
# X global lock should block
--send ALTER DATABASE db1 DEFAULT CHARACTER SET utf8

connection default;
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
  WHERE state='Waiting for global read lock'
  AND info='ALTER DATABASE db1 DEFAULT CHARACTER SET utf8';
--source include/wait_condition.inc
UNLOCK TABLES;

connection con2;
--echo # Reaping ALTER DATABASE db1 DEFAULT CHARACTER SET utf8
--reap

connection default;
FLUSH TABLE WITH READ LOCK;

connection con2;
# S global lock should not block
FLUSH TABLE WITH READ LOCK;
UNLOCK TABLES;

connection default;
UNLOCK TABLES;
DROP DATABASE db1;
disconnect con2;
disconnect con3;


--echo #
--echo # Bug#56292 Deadlock with ALTER TABLE and MERGE tables
--echo #

--disable_warnings
DROP TABLE IF EXISTS t1, t2, m1;
--enable_warnings

CREATE TABLE t1(a INT) engine=MyISAM;
CREATE TABLE t2(a INT) engine=MyISAM;
CREATE TABLE m1(a INT) engine=MERGE UNION=(t1, t2);

INSERT INTO t1 VALUES (1), (2);
INSERT INTO t2 VALUES (3), (4);

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

connection con1;
--echo # We need EXECUTE 2 since ALTER TABLE does SU => SNW => X and we want
--echo # to stop at the second upgrade.
SET DEBUG_SYNC= 'mdl_upgrade_lock SIGNAL upgrade WAIT_FOR continue EXECUTE 2';
--echo # Sending:
--send ALTER TABLE m1 engine=MERGE UNION=(t2, t1)

connection con2;
--echo # Waiting for ALTER TABLE to try lock upgrade
SET DEBUG_SYNC= 'now WAIT_FOR upgrade';
SET DEBUG_SYNC= 'now SIGNAL continue';
SET DEBUG_SYNC= 'now WAIT_FOR upgrade';
--echo # Sending:
--send DELETE FROM t2 WHERE a = 3

connection con3;
--echo # Check that DELETE is waiting on a metadata lock and not a table lock.
let $wait_condition=
  SELECT COUNT(*) = 1 FROM information_schema.processlist
  WHERE state = "Waiting for table metadata lock" AND
        info = "DELETE FROM t2 WHERE a = 3";
--source include/wait_condition.inc
--echo # Now that DELETE blocks on a metadata lock, we should be able to do
--echo # SELECT * FROM m1 here. SELECT used to be blocked by a DELETE table
--echo # lock request.
--send SELECT * FROM m1 WHERE a < 3

connection default;
--echo # Resuming ALTER TABLE
SET DEBUG_SYNC= 'now SIGNAL continue';

connection con1;
--echo # Reaping: ALTER TABLE m1 engine=MERGE UNION=(t2, t1)
--reap
connection con2;
--echo # Reaping: DELETE FROM t2 WHERE a = 3
--reap
connection con3;
--echo # Reaping: SELECT * FROM m1 WHERE a < 3
--reap
connection default;
DROP TABLE m1, t1, t2;
SET DEBUG_SYNC= 'RESET';
disconnect con1;
disconnect con2;
disconnect con3;


--echo #
--echo # MDEV-12620 - set lock_wait_timeout = 1;flush tables with read lock;
--echo #              lock not released after timeout
--echo #
CREATE TABLE t1(a INT) ENGINE=InnoDB;
SET debug_sync='open_tables_after_open_and_process_table SIGNAL ready WAIT_FOR go';
send SELECT * FROM t1;

connect (con1,localhost,root,,);
SET debug_sync='now WAIT_FOR ready';
# lock_wait_timeout should be 0 in 10.3, so that we don't have to wait at all
SET lock_wait_timeout=1;
--error ER_LOCK_WAIT_TIMEOUT
FLUSH TABLES WITH READ LOCK;
SET debug_sync='now SIGNAL go';

connection default;
reap;
SET debug_sync='RESET';
DROP TABLE t1;

disconnect con1;


# Check that all connections opened by test cases in this file are really
# gone so execution of other tests won't be affected by their presence.
--source include/wait_until_count_sessions.inc