Bug#28733170: PERFORMANCE_SCHEMA.DATA_LOCKS DOES NOT HANDLE JOINS CORRECTLY

The iterators in table_data_locks::m_iterator[] where not being reset during ::reset_position(),
which caused them to report no more rows when reused subsequently.
Same problem was in table_data_lock_waits::reset_position().
Additionally, PFS_data_lock_wait_container::clear() didn't reset m_logical_row_index.
This patch introduces MTRs which expose these problems, fixes them,
and also changes some of integer types to size_t, to make number of warnings smaller.

Reviewed-by: Marc Alff <marc.alff@oracle.com>

Author: Jakub Łopuszański

mysql-test/suite/perfschema/r/data_lock_waits_join.result

@@ -0,0 +1,66 @@
+Bug #28733170
+PERFORMANCE_SCHEMA.DATA_LOCKS DOES NOT HANDLE JOINS CORRECTLY
+CREATE TABLE t1(
+id INT PRIMARY KEY
+) Engine=InnoDB;
+BEGIN;
+INSERT INTO t1 VALUES (1),(2);
+SELECT * FROM t1 FOR UPDATE;
+id
+1
+2
+BEGIN;
+SET DEBUG_SYNC = 'lock_wait_will_wait SIGNAL C1_will_wait';
+SELECT * FROM t1 WHERE id=1 FOR UPDATE;
+SET DEBUG_SYNC = 'now WAIT_FOR C1_will_wait';
+CREATE TABLE t2 (
+id INT PRIMARY KEY AUTO_INCREMENT,
+lock_id VARCHAR(200) NOT NULL
+) Engine=InnoDB;
+INSERT INTO t2 (lock_id)
+SELECT blocking_engine_lock_id
+FROM performance_schema.data_lock_waits;
+SELECT COUNT(*) FROM t2;
+COUNT(*)
+2
+SELECT COUNT(t2.id)
+FROM t2
+JOIN performance_schema.data_lock_waits dlw
+ON(dlw.blocking_engine_lock_id = t2.lock_id)
+ORDER BY t2.id;
+COUNT(t2.id)
+2
+CREATE TABLE t3 (
+id INT PRIMARY KEY AUTO_INCREMENT,
+lock_id VARCHAR(200) NOT NULL
+) Engine=InnoDB;
+INSERT INTO t3 (lock_id)
+SELECT requesting_engine_lock_id
+FROM performance_schema.data_lock_waits
+LIMIT 1;
+INSERT INTO t3 (lock_id)
+SELECT requesting_engine_lock_id
+FROM performance_schema.data_lock_waits
+LIMIT 1;
+SELECT COUNT(DISTINCT t3.id)
+FROM t3
+JOIN performance_schema.data_lock_waits dlw
+ON(dlw.requesting_engine_lock_id = t3.lock_id)
+ORDER BY t3.id;
+COUNT(DISTINCT t3.id)
+2
+SELECT COUNT(*) FROM performance_schema.data_lock_waits;
+COUNT(*)
+2
+SELECT COUNT(*)
+FROM performance_schema.data_lock_waits
+JOIN performance_schema.data_locks r
+ON(r.engine_lock_id = requesting_engine_lock_id)
+JOIN performance_schema.data_locks b
+ON(b.engine_lock_id = blocking_engine_lock_id);
+COUNT(*)
+2
+DROP TABLE t2;
+DROP TABLE t3;
+ROLLBACK;
+DROP TABLE t1;

mysql-test/suite/perfschema/r/data_locks_join.result

@@ -0,0 +1,32 @@
+Bug #28733170
+PERFORMANCE_SCHEMA.DATA_LOCKS DOES NOT HANDLE JOINS CORRECTLY
+CREATE TABLE t1(
+id INT PRIMARY KEY
+) Engine=InnoDB;
+BEGIN;
+INSERT INTO t1 VALUES (1),(2);
+SELECT * FROM t1 FOR UPDATE;
+id
+1
+2
+CREATE TABLE t2 (
+id INT PRIMARY KEY AUTO_INCREMENT,
+lock_id VARCHAR(200) NOT NULL
+) Engine=InnoDB;
+INSERT INTO t2 (lock_id)
+SELECT engine_lock_id
+FROM performance_schema.data_locks
+WHERE object_name='t1';
+SELECT COUNT(*) FROM t2;
+COUNT(*)
+6
+SELECT COUNT(t2.id)
+FROM t2
+JOIN performance_schema.data_locks dl
+ON(dl.engine_lock_id = t2.lock_id)
+ORDER BY t2.id;
+COUNT(t2.id)
+6
+DROP TABLE t2;
+ROLLBACK;
+DROP TABLE t1;