1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
#
# Code coverage testing of TRUNCATE TABLE.
#
# Ingo Struewing, 2009-07-20
#
--source include/have_debug_sync.inc
SET DEBUG_SYNC='RESET';
--let $MYSQLD_DATADIR= `SELECT @@datadir`
--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings
--echo #
--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.
#
--echo #
--echo # connection con1
--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.
#
--echo #
--echo # connection default
--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().
#
--echo #
--echo # connection con2
--connect (con2, localhost, root,,)
SET DEBUG_SYNC='now WAIT_FOR waiting';
let $invisible_assignment_in_select = `SELECT @id := $ID`;
KILL QUERY @id;
--disconnect con2
--echo #
--echo # connection default
--connection default
--error ER_QUERY_INTERRUPTED
reap;
UNLOCK TABLES;
--echo #
--echo # connection con1
--connection con1
--echo # Release shared metadata lock by closing HANDLER.
HANDLER t1 CLOSE;
--disconnect con1
--echo #
--echo # connection default
--connection default
DROP TABLE t1;
SET DEBUG_SYNC='RESET';
########
# Attack acquire_exclusive_locks(). Hold a global read lock.
# Non-LOCK TABLE case.
#
CREATE TABLE t1 (c1 INT);
INSERT INTO t1 VALUES (1);
#
# Start a transaction and execute a DML in it. Since 5.4.4 this leaves
# a shared meta data lock (MDL) behind. TRUNCATE shall block on it.
#
--echo #
--echo # connection con1
--connect (con1, localhost, root,,)
START TRANSACTION;
INSERT INTO t1 VALUES (2);
#
# Get connection id of default connection.
# Start TRUNCATE, which will block on acquire_exclusive_locks().
#
--echo #
--echo # connection default
--connection default
let $ID= `SELECT @id := CONNECTION_ID()`;
SET DEBUG_SYNC='mdl_acquire_lock_wait 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().
#
--echo #
--echo # connection con1
--connection con1
SET DEBUG_SYNC='now WAIT_FOR waiting';
let $invisible_assignment_in_select = `SELECT @id := $ID`;
KILL QUERY @id;
--echo #
--echo # connection default
--connection default
--error ER_QUERY_INTERRUPTED
reap;
--echo #
--echo # connection con1
--connection con1
--echo # Release SW lock by committing transaction.
COMMIT;
--disconnect con1
--echo #
--echo # connection default
--connection default
UNLOCK TABLES;
DROP TABLE t1;
SET DEBUG_SYNC='RESET';
|
