MDEV-7660 - MySQL WL#6671 "Improve scalability by not using thr_lock.c locks

            for InnoDB tables"

Don't use thr_lock.c locks for InnoDB tables. Below is list of changes that
were needed to implement this:
- HANDLER OPEN acquireis MDL_SHARED_READ instead of MDL_SHARED
- HANDLER READ calls external_lock() even if SE is not going to be locked by
  THR_LOCK
- InnoDB lock wait timeouts are now honored which are much shorter by default
  than server lock wait timeouts (1 year vs 50 seconds)
- with @@autocommit= 1 LOCK TABLES disables autocommit implicitely, though
  user still sees @@autocommt= 1
- the above starts implicit transaction
- transactions started by LOCK TABLES are now rolled back on disconnect
  (previously everything was committed due to autocommit)
- transactions started by LOCK TABLES are now rolled back by ROLLBACK
  (previously everything was committed due to autocommit)
- it is now impossible to change BINLOG_FORMAT under LOCK TABLES (at least
  to statement) due to running transaction
- LOCK TABLES WRITE is additionally handled by MDL
- ...in contrast LOCK TABLES READ protection against DML is pure InnoDB
- combining transactional and non-transactional tables under LOCK TABLES
  may cause rolled back changes in transactional table and "committed"
  changes in non-transactional table
- user may disable innodb_table_locks, which will cause LOCK TABLES to be
  noop basically

Removed tests for BUG#45143 and BUG#55930 which cover InnoDB + THR_LOCK. To
operate properly these tests require code flow to go through THR_LOCK debug
sync points, which is not the case after this patch. These tests are removed
by WL#6671 as well. An alternative is to port them to different storage engine.

1 files changed, 0 insertions, 80 deletions

diff --git a/mysql-test/t/truncate_coverage.test b/mysql-test/t/truncate_coverage.test
index 0834f7a3eca..3351ce84232 100644
--- a/mysql-test/t/truncate_coverage.test
+++ b/mysql-test/t/truncate_coverage.test
@@ -17,86 +17,6 @@ DROP TABLE IF EXISTS t1;
 --echo # Bug#20667 - Truncate table fails for a write locked table
 --echo #
 ########
-# Attack wait_while_table_is_used(). Kill query while trying to
-# upgrade MDL.
-#
-CREATE TABLE t1 (c1 INT);
-INSERT INTO t1 VALUES (1);
-#
-# Acquire a shared metadata lock on table by opening HANDLER for it and wait.
-# TRUNCATE shall block on this metadata lock.
-# We can't use normal DML as such statements would also block LOCK TABLES.
-#
---connect (con1, localhost, root,,)
-HANDLER t1 OPEN;
-#
-# Get connection id of default connection.
-# Lock the table and start TRUNCATE, which will block on MDL upgrade.
-#
---connection default
-let $ID= `SELECT @id := CONNECTION_ID()`;
-LOCK TABLE t1 WRITE;
-SET DEBUG_SYNC='mdl_upgrade_lock SIGNAL waiting';
-send TRUNCATE TABLE t1;
-#
-# Get the default connection ID into a variable in an invisible statement.
-# Kill the TRUNCATE query. This shall result in an error return
-# from wait_while_table_is_used().
-#
---connect (con2, localhost, root,,)
-SET DEBUG_SYNC='now WAIT_FOR waiting';
-let $invisible_assignment_in_select = `SELECT @id := $ID`;
-KILL QUERY @id;
---disconnect con2
---connection default
---error ER_QUERY_INTERRUPTED
-reap;
-UNLOCK TABLES;
---connection con1
---echo # Release shared metadata lock by closing HANDLER.
-HANDLER t1 CLOSE;
---disconnect con1
---connection default
-DROP TABLE t1;
-SET DEBUG_SYNC='RESET';
-########
-# Attack reopen_tables(). Remove form file.
-#
-CREATE TABLE t1 (c1 INT);
-INSERT INTO t1 VALUES (1);
-#
-# Acquire a shared metadata lock on table by opening HANDLER for it and wait.
-# TRUNCATE shall block on this metadata lock.
-# We can't use normal DML as such statements would also block LOCK TABLES.
-#
---connect (con1, localhost, root,,)
-HANDLER t1 OPEN;
-#
-# Lock the table and start TRUNCATE, which will block on MDL upgrade.
-#
---connection default
-LOCK TABLE t1 WRITE;
-SET DEBUG_SYNC='mdl_upgrade_lock SIGNAL waiting';
-send TRUNCATE TABLE t1;
-#
-# Remove datafile.
-# Commit to let TRUNCATE continue.
-#
---connect (con2, localhost, root,,)
-SET DEBUG_SYNC='now WAIT_FOR waiting';
---remove_file $MYSQLD_DATADIR/test/t1.frm
---disconnect con2
---connection con1
-HANDLER t1 CLOSE;
---disconnect con1
---connection default
---error ER_NO_SUCH_TABLE
-reap;
-UNLOCK TABLES;
---error ER_BAD_TABLE_ERROR
-DROP TABLE t1;
-SET DEBUG_SYNC='RESET';
-########
 # Attack acquire_exclusive_locks(). Hold a global read lock.
 # Non-LOCK TABLE case.
 #