#
# Locking related tests which use DEBUG_SYNC facility.
#
--source include/have_debug_sync.inc
# We need InnoDB to be able use TL_WRITE_ALLOW_WRITE type of locks in our tests.
--source include/have_innodb.inc

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


--echo #
--echo # Test for bug #45143 "All connections hang on concurrent ALTER TABLE".
--echo #
--echo # Concurrent execution of statements which required weak write lock
--echo # (TL_WRITE_ALLOW_WRITE) on several instances of the same table and
--echo # statements which tried to acquire stronger write lock (TL_WRITE,
--echo # TL_WRITE_ALLOW_READ) on this table might have led to deadlock.
--disable_warnings
drop table if exists t1;
--enable_warnings
--echo # Create auxiliary connections used through the test.
connect (con_bug45143_1,localhost,root,,test,,);
connect (con_bug45143_3,localhost,root,,test,,);
connect (con_bug45143_2,localhost,root,,test,,);
connection default;
--echo # Reset DEBUG_SYNC facility before using it.
set debug_sync= 'RESET';
--echo # Turn off logging so calls to locking subsystem performed
--echo # for general_log table won't interfere with our test.
set @old_general_log = @@global.general_log;
set @@global.general_log= OFF;

create table t1 (i int) engine=InnoDB;
insert into t1 values (1);
--echo # Prepare user lock which will be used for resuming execution of
--echo # the first statement after it acquires TL_WRITE_ALLOW_WRITE lock.
select get_lock("lock_bug45143_wait", 0);

--echo # Switch to connection 'con_bug45143_1'.
connection con_bug45143_1;
--echo # Sending:
--send insert into t1 values (get_lock("lock_bug45143_wait", 100));

--echo # Switch to connection 'con_bug45143_2'.
connection con_bug45143_2;
--echo # Wait until the above INSERT takes TL_WRITE_ALLOW_WRITE lock on 't1'
--echo # and then gets blocked on user lock 'lock_bug45143_wait'.
let $wait_condition= select count(*)= 1 from information_schema.processlist
                       where state= 'User lock' and
                             info='insert into t1 values (get_lock("lock_bug45143_wait", 100))';
--source include/wait_condition.inc
--echo # Ensure that upcoming SELECT waits after acquiring TL_WRITE_ALLOW_WRITE
--echo # lock for the first instance of 't1'.
set debug_sync='thr_multi_lock_after_thr_lock SIGNAL parked WAIT_FOR go';
--echo # Sending:
--send select count(*) > 0 from t1 as a, t1 as b for update;

--echo # Switch to connection 'con_bug45143_3'.
connection con_bug45143_3;
--echo # Wait until the above SELECT ... FOR UPDATE is blocked after
--echo # acquiring lock for the the first instance of 't1'.
set debug_sync= 'now WAIT_FOR parked';
--echo # Send LOCK TABLE statement which will try to get TL_WRITE lock on 't1':
--send lock table t1 write;

--echo # Switch to connection 'default'.
connection default;
--echo # Wait until this LOCK TABLES statement starts waiting for table lock.
let $wait_condition= select count(*)= 1 from information_schema.processlist
                       where state= 'Locked' and
                             info='lock table t1 write';
--source include/wait_condition.inc
--echo # Allow SELECT ... FOR UPDATE to resume.
--echo # Since it already has TL_WRITE_ALLOW_WRITE lock on the first instance
--echo # of 't1' it should be able to get lock on the second instance without
--echo # waiting, even although there is another thread which has such lock
--echo # on this table and also there is a thread waiting for a TL_WRITE on it.
set debug_sync= 'now SIGNAL go';

--echo # Switch to connection 'con_bug45143_2'.
connection con_bug45143_2;
--echo # Reap SELECT ... FOR UPDATE
--reap

--echo # Switch to connection 'default'.
connection default;
--echo # Resume execution of the INSERT statement.
select release_lock("lock_bug45143_wait");

--echo # Switch to connection 'con_bug45143_1'.
connection con_bug45143_1;
--echo # Reap INSERT statement.
--reap

--echo # Switch to connection 'con_bug45143_3'.
connection con_bug45143_3;
--echo # Reap LOCK TABLES statement.
--reap
unlock tables;

--echo # Switch to connection 'default'.
connection default;
--echo # Do clean-up.
disconnect con_bug45143_1;
disconnect con_bug45143_2;
disconnect con_bug45143_3;
set debug_sync= 'RESET';
set @@global.general_log= @old_general_log;
drop table t1;


# 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