#At file:///home2/mydev/bzrroot/mysql-6.0-bug37780-5/ based on revid:rafal.somla@stripped
2802 Ingo Struewing 2009-05-13
Bug#37780 - main.kill fails randomly
The test case main.kill did not work reliably.
The following problems have been identified:
1. A kill signal could go lost if it came in, short before a thread went
reading on the client connection.
2. A kill signal could go lost if it came in, short before a thread went
waiting on a condition variable.
These problems have been solved as follows. Please see also added code
comments for more details.
1. There is no safe way to detect, when a thread enters the blocking
state of a read(2) or recv(2) system call, where it can be interrupted
by a signal. Hence it is not possible to wait for the right moment to
send a kill signal. To be safe, we need to close the connection before
sending a kill signal. If the signal arrives before start of read, read
fails on the closed connection.
2. Before waiting on a condition variable, we register it together with
a synchronizating mutex in THD::mysys_var. After this, we need to test
THD::killed again. At some places we did only test it in a loop
condition before the registration. When THD::killed had been set between
this test and the registration, we entered waiting without noticing the
killed flag.
In addition to the above, a re-write of the main.kill test case has been
done. All sleeps have been replaced by Debug Sync Facility
synchronization. The test case run time decreased from over 30 to below
three seconds. A couple of sync points have been added to the server
code.
@ include/config-netware.h
Bug#37780 - main.kill fails randomly
Removed SIGNAL_WITH_VIO_CLOSE.
@ include/config-win.h
Bug#37780 - main.kill fails randomly
Removed SIGNAL_WITH_VIO_CLOSE.
@ mysql-test/r/kill.result
Bug#37780 - main.kill fails randomly
Updated test result.
@ mysql-test/t/disabled.def
Bug#37780 - main.kill fails randomly
Re-enabled test case.
@ mysql-test/t/kill.test
Bug#37780 - main.kill fails randomly
Re-wrote test case to use Debug Sync points instead of sleeps.
@ sql/event_queue.cc
Bug#37780 - main.kill fails randomly
Fixed kill detection in Event_queue::cond_wait()
by adding a check after enter_cond().
@ sql/lock.cc
Bug#37780 - main.kill fails randomly
Moved Debug Sync points behind enter_cond().
Fixed comments.
@ sql/mdl.cc
Bug#37780 - main.kill fails randomly
Removed an unused sync point.
@ sql/slave.cc
Bug#37780 - main.kill fails randomly
Fixed kill detection in start_slave_thread()
by adding a check after enter_cond().
Removed SIGNAL_WITH_VIO_CLOSE.
@ sql/sql_base.cc
Bug#37780 - main.kill fails randomly
Fixed kill detection in close_cached_tables() and
tdc_wait_for_old_versions()
by adding checks after enter_cond().
@ sql/sql_class.cc
Bug#37780 - main.kill fails randomly
Removed SIGNAL_WITH_VIO_CLOSE.
Swapped order of kill and close in THD::awake().
Added comments.
@ sql/sql_class.h
Bug#37780 - main.kill fails randomly
Removed SIGNAL_WITH_VIO_CLOSE.
Added a comment to THD::killed.
@ sql/sql_connect.cc
Bug#37780 - main.kill fails randomly
Removed SIGNAL_WITH_VIO_CLOSE.
@ sql/sql_parse.cc
Bug#37780 - main.kill fails randomly
Added a sync point in do_command().
@ sql/sql_select.cc
Bug#37780 - main.kill fails randomly
Added a sync point in JOIN::optimize().
@ vio/viosocket.c
Bug#37780 - main.kill fails randomly
Added DBUG_PRINTs.
modified:
include/config-netware.h
include/config-win.h
mysql-test/r/kill.result
mysql-test/t/disabled.def
mysql-test/t/kill.test
sql/event_queue.cc
sql/lock.cc
sql/mdl.cc
sql/slave.cc
sql/sql_base.cc
sql/sql_class.cc
sql/sql_class.h
sql/sql_connect.cc
sql/sql_parse.cc
sql/sql_select.cc
vio/viosocket.c
=== modified file 'include/config-netware.h'
--- a/include/config-netware.h 2008-10-15 22:53:18 +0000
+++ b/include/config-netware.h 2009-05-13 13:22:15 +0000
@@ -108,9 +108,6 @@ extern "C" {
/* signals do not interrupt sockets */
#define SIGNALS_DONT_BREAK_READ 1
-/* signal by closing the sockets */
-#define SIGNAL_WITH_VIO_CLOSE 1
-
/* On NetWare, stack grows towards lower address */
#define STACK_DIRECTION -1
=== modified file 'include/config-win.h'
--- a/include/config-win.h 2009-04-03 15:14:49 +0000
+++ b/include/config-win.h 2009-05-13 13:22:15 +0000
@@ -222,11 +222,6 @@ typedef SSIZE_T ssize_t;
/* ERROR is defined in wingdi.h */
#undef ERROR
-/* We need to close files to break connections on shutdown */
-#ifndef SIGNAL_WITH_VIO_CLOSE
-#define SIGNAL_WITH_VIO_CLOSE
-#endif
-
/* All windows servers should support .sym files */
#undef USE_SYMDIR
#define USE_SYMDIR
=== modified file 'mysql-test/r/kill.result'
--- a/mysql-test/r/kill.result 2009-02-13 17:00:42 +0000
+++ b/mysql-test/r/kill.result 2009-05-13 13:22:15 +0000
@@ -1,141 +1,189 @@
-set @old_concurrent_insert= @@global.concurrent_insert;
-set @@global.concurrent_insert= 0;
-drop table if exists t1, t2, t3;
-create table t1 (kill_id int);
-insert into t1 values(connection_id());
-select ((@id := kill_id) - kill_id) from t1;
-((@id := kill_id) - kill_id)
-0
-kill @id;
-select ((@id := kill_id) - kill_id) from t1;
-((@id := kill_id) - kill_id)
-0
-select @id != connection_id();
-@id != connection_id()
+SET DEBUG_SYNC = 'RESET';
+DROP TABLE IF EXISTS t1, t2, t3;
+SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
+SET DEBUG_SYNC= 'before_do_command_net_read SIGNAL con1_read';
+SET DEBUG_SYNC='now WAIT_FOR con1_read';
+KILL @id;
+SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
+SELECT 1;
+Got one of the listed errors
+SELECT 1;
+1
+1
+SELECT @id != CONNECTION_ID();
+@id != CONNECTION_ID()
1
-select 4;
+SELECT 4;
4
4
-drop table t1;
-kill (select count(*) from mysql.user);
+KILL (SELECT COUNT(*) FROM mysql.user);
ERROR 42000: This version of MySQL doesn't yet support 'Usage of subqueries or stored function calls as part of this statement'
-create table t1 (id int primary key);
-create table t2 (id int unsigned not null);
-insert into t2 select id from t1;
-create table t3 (kill_id int);
-insert into t3 values(connection_id());
-select id from t1 where id in (select distinct a.id from t2 a, t2 b, t2 c, t2 d group by a.id, b.id, c.id, d.id having a.id between 10 and 20);
-select ((@id := kill_id) - kill_id) from t3;
-((@id := kill_id) - kill_id)
-0
-kill @id;
+SET DEBUG_SYNC = 'RESET';
+SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
+SET DEBUG_SYNC= 'before_do_command_net_read SIGNAL in_sync WAIT_FOR kill';
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL @id;
+SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
+SELECT 1;
+Got one of the listed errors
+SELECT 1;
+1
+1
+SELECT @id != CONNECTION_ID();
+@id != CONNECTION_ID()
+1
+SELECT 4;
+4
+4
+SET DEBUG_SYNC = 'RESET';
+CREATE TABLE t1 (id INT PRIMARY KEY AUTO_INCREMENT);
+CREATE TABLE t2 (id INT UNSIGNED NOT NULL);
+INSERT INTO t1 VALUES
+(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0),
+(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0),
+(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0),
+(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0);
+INSERT t1 SELECT 0 FROM t1 AS a1, t1 AS a2 LIMIT 4032;
+INSERT INTO t2 SELECT id FROM t1;
+SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
+SET DEBUG_SYNC= 'before_acos_function SIGNAL in_sync';
+SELECT id FROM t1 WHERE id IN
+(SELECT DISTINCT a.id FROM t2 a, t2 b, t2 c, t2 d
+GROUP BY ACOS(1/a.id), b.id, c.id, d.id
+HAVING a.id BETWEEN 10 AND 20);
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL @id;
+SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
Got one of the listed errors
-drop table t1, t2, t3;
-select get_lock("a", 10);
-get_lock("a", 10)
-1
-select get_lock("a", 10);
-get_lock("a", 10)
-NULL
-select 1;
-1
-1
-select RELEASE_LOCK("a");
-RELEASE_LOCK("a")
-1
-create table t1(f1 int);
-create function bug27563() returns int(11)
-deterministic
-begin
-declare continue handler for sqlstate '70100' set @a:= 'killed';
-declare continue handler for sqlexception set @a:= 'exception';
-set @a= get_lock("lock27563", 10);
-return 1;
-end|
-select get_lock("lock27563",10);
-get_lock("lock27563",10)
-1
-insert into t1 values (bug27563());
-ERROR 70100: Query execution was interrupted
-select @a;
-@a
-NULL
-select * from t1;
-f1
-insert into t1 values(0);
-update t1 set f1= bug27563();
-ERROR 70100: Query execution was interrupted
-select @a;
-@a
-NULL
-select * from t1;
-f1
-0
-insert into t1 values(1);
-delete from t1 where bug27563() is null;
-ERROR 70100: Query execution was interrupted
-select @a;
-@a
-NULL
-select * from t1;
-f1
-0
-1
-select * from t1 where f1= bug27563();
-ERROR 70100: Query execution was interrupted
-select @a;
-@a
-NULL
-create procedure proc27563()
-begin
-declare continue handler for sqlstate '70100' set @a:= 'killed';
-declare continue handler for sqlexception set @a:= 'exception';
-select get_lock("lock27563",10);
-select "shouldn't be selected";
-end|
-call proc27563();
-get_lock("lock27563",10)
-NULL
-ERROR 70100: Query execution was interrupted
-select @a;
-@a
-NULL
-create table t2 (f2 int);
-create trigger trg27563 before insert on t1 for each row
-begin
-declare continue handler for sqlstate '70100' set @a:= 'killed';
-declare continue handler for sqlexception set @a:= 'exception';
-set @a:= get_lock("lock27563",10);
-insert into t2 values(1);
-end|
-insert into t1 values(2),(3);
-ERROR 70100: Query execution was interrupted
-select @a;
-@a
-NULL
-select * from t1;
+SELECT 1;
+1
+1
+SET DEBUG_SYNC = 'RESET';
+DROP TABLE t1, t2;
+SET DEBUG_SYNC= 'before_acos_function SIGNAL in_sync WAIT_FOR kill';
+SELECT ACOS(0);
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+ACOS(0)
+1.5707963267948966
+SELECT 1;
+1
+1
+SELECT @id = CONNECTION_ID();
+@id = CONNECTION_ID()
+1
+SET DEBUG_SYNC = 'RESET';
+CREATE TABLE t1 (f1 INT);
+CREATE FUNCTION bug27563() RETURNS INT(11)
+DETERMINISTIC
+BEGIN
+DECLARE CONTINUE HANDLER FOR SQLSTATE '70100' SET @a:= 'killed';
+DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+SET DEBUG_SYNC= 'now SIGNAL in_sync WAIT_FOR kill';
+RETURN 1;
+END|
+INSERT INTO t1 VALUES (bug27563());
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+ERROR 70100: Query execution was interrupted
+SELECT * FROM t1;
+f1
+SET DEBUG_SYNC = 'RESET';
+INSERT INTO t1 VALUES(0);
+UPDATE t1 SET f1= bug27563();
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+ERROR 70100: Query execution was interrupted
+SELECT * FROM t1;
+f1
+0
+SET DEBUG_SYNC = 'RESET';
+INSERT INTO t1 VALUES(1);
+DELETE FROM t1 WHERE bug27563() IS NULL;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+ERROR 70100: Query execution was interrupted
+SELECT * FROM t1;
f1
0
1
-select * from t2;
-f2
-select release_lock("lock27563");
-release_lock("lock27563")
+SET DEBUG_SYNC = 'RESET';
+SELECT * FROM t1 WHERE f1= bug27563();
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+ERROR 70100: Query execution was interrupted
+SELECT * FROM t1;
+f1
+0
+1
+SET DEBUG_SYNC = 'RESET';
+DROP FUNCTION bug27563;
+CREATE PROCEDURE proc27563()
+BEGIN
+DECLARE CONTINUE HANDLER FOR SQLSTATE '70100' SET @a:= 'killed';
+DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+SELECT "should be selected" AS procedure_activity_1;
+SET DEBUG_SYNC= 'now SIGNAL in_sync WAIT_FOR kill';
+SELECT "shouldn't be selected" AS procedure_activity_2;
+END|
+CALL proc27563();
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+procedure_activity_1
+should be selected
+ERROR 70100: Query execution was interrupted
+SELECT * FROM t1;
+f1
+0
1
-drop table t1, t2;
-drop function bug27563;
-drop procedure proc27563;
+SET DEBUG_SYNC = 'RESET';
+DROP PROCEDURE proc27563;
+CREATE TABLE t2 (f2 INT);
+CREATE TRIGGER trg27563 BEFORE INSERT ON t1 FOR EACH ROW
+BEGIN
+DECLARE CONTINUE HANDLER FOR SQLSTATE '70100' SET @a:= 'killed';
+DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+INSERT INTO t2 VALUES(0);
+SET DEBUG_SYNC= 'now SIGNAL in_sync WAIT_FOR kill';
+INSERT INTO t2 VALUES(1);
+END|
+INSERT INTO t1 VALUES(2),(3);
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+ERROR 70100: Query execution was interrupted
+SELECT * FROM t1;
+f1
+0
+1
+SELECT * FROM t2;
+f2
+0
+SET DEBUG_SYNC = 'RESET';
+DROP TABLE t1, t2;
+SET DEBUG_SYNC= 'before_join_optimize SIGNAL in_sync';
PREPARE stmt FROM 'EXPLAIN SELECT * FROM t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11,t12,t13,t14,t15,t16,t17,t18,t19,t20,t21,t22,t23,t24,t25,t26,t27,t28,t29,t30,t31,t32,t33,t34,t35,t36,t37,t38,t39,t40 WHERE a1=a2 AND a2=a3 AND a3=a4 AND a4=a5 AND a5=a6 AND a6=a7 AND a7=a8 AND a8=a9 AND a9=a10 AND a10=a11 AND a11=a12 AND a12=a13 AND a13=a14 AND a14=a15 AND a15=a16 AND a16=a17 AND a17=a18 AND a18=a19 AND a19=a20 AND a20=a21 AND a21=a22 AND a22=a23 AND a23=a24 AND a24=a25 AND a25=a26 AND a26=a27 AND a27=a28 AND a28=a29 AND a29=a30 AND a30=a31 AND a31=a32 AND a32=a33 AND a33=a34 AND a34=a35 AND a35=a36 AND a36=a37 AND a37=a38 AND a38=a39 AND a39=a40 ';
EXECUTE stmt;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+ERROR 70100: Query execution was interrupted
+SET DEBUG_SYNC = 'RESET';
#
# Bug#19723: kill of active connection yields different error code
# depending on platform.
#
-# Connection: con2.
-KILL CONNECTION_ID();
-# CR_SERVER_LOST, CR_SERVER_GONE_ERROR, depending on the timing
-# of close of the connection socket
+# Connection: con1.
+SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
+KILL @id;
+SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
+# ER_SERVER_SHUTDOWN, CR_SERVER_GONE_ERROR, CR_SERVER_LOST,
+# depending on the timing of close of the connection socket
SELECT 1;
Got one of the listed errors
-set @@global.concurrent_insert= @old_concurrent_insert;
+SELECT 1;
+1
+1
+SELECT @id != CONNECTION_ID();
+@id != CONNECTION_ID()
+1
+SET DEBUG_SYNC = 'RESET';
=== modified file 'mysql-test/t/disabled.def'
--- a/mysql-test/t/disabled.def 2009-04-03 15:14:49 +0000
+++ b/mysql-test/t/disabled.def 2009-05-13 13:22:15 +0000
@@ -13,7 +13,6 @@ cast : Bug#35594 2008-03
events_bugs : Bug#37774 2008-10-08 alik
innodb : Bug#41299 2008-12-08 alik
innodb_bug39438 : BUG#42383 2009-01-28 lsoares "This fails in embedded and on windows. Note that this test is not run on windows and on embedded in PB for main trees currently"
-kill : Bug#37780 2008-12-03 HHunger need some changes to be robust enough for pushbuild.
#concurrent_innodb_safelog: disabled for embedded server due to bug#43733 Select on processlist let the embedded server crash (concurrent_innodb_safelog).
#concurrent_innodb_unsafelog: disabled for embedded server due to bug#43733.
query_cache_28249 : Bug#43861 2009-03-25 main.query_cache_28249 fails sporadically
=== modified file 'mysql-test/t/kill.test'
--- a/mysql-test/t/kill.test 2009-02-13 17:00:42 +0000
+++ b/mysql-test/t/kill.test 2009-05-13 13:22:15 +0000
@@ -1,306 +1,314 @@
-# This test doesn't work with the embedded version as this code
-# assumes that one query is running while we are doing queries on
-# a second connection.
-# This would work if mysqltest run would be threaded and handle each
-# connection in a separate thread.
-#
-- source include/not_embedded.inc
+-- source include/have_debug_sync.inc
-# Disable concurrent inserts to avoid test failures when reading the
-# connection id which was inserted into a table by another thread.
-set @old_concurrent_insert= @@global.concurrent_insert;
-set @@global.concurrent_insert= 0;
+--disable_warnings
+SET DEBUG_SYNC = 'RESET';
+DROP TABLE IF EXISTS t1, t2, t3;
+--enable_warnings
connect (con1, localhost, root,,);
connect (con2, localhost, root,,);
#remember id of con1
connection con1;
---disable_warnings
-drop table if exists t1, t2, t3;
---enable_warnings
-
--disable_reconnect
-create table t1 (kill_id int);
-insert into t1 values(connection_id());
+let $ID= `SELECT @id := CONNECTION_ID()`;
+connection con2;
+let $ignore= `SELECT @id := $ID`;
+connection con1;
+SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
+SET DEBUG_SYNC= 'before_do_command_net_read SIGNAL con1_read';
#kill con1
connection con2;
-select ((@id := kill_id) - kill_id) from t1;
-kill @id;
+SET DEBUG_SYNC='now WAIT_FOR con1_read';
+KILL @id;
+SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
connection con1;
---sleep 2
-
---disable_query_log
---disable_result_log
-# One of the following statements should fail
---error 0,2006,2013
-select 1;
---error 0,2006,2013
-select 1;
---enable_query_log
---enable_result_log
+--error 1053,2006,2013
+SELECT 1;
--enable_reconnect
# this should work, and we should have a new connection_id()
-select ((@id := kill_id) - kill_id) from t1;
-select @id != connection_id();
+SELECT 1;
+let $ignore= `SELECT @id := $ID`;
+SELECT @id != CONNECTION_ID();
#make sure the server is still alive
connection con2;
-select 4;
-drop table t1;
+SELECT 4;
connection default;
--error ER_NOT_SUPPORTED_YET
-kill (select count(*) from mysql.user);
+KILL (SELECT COUNT(*) FROM mysql.user);
+SET DEBUG_SYNC = 'RESET';
+connection con1;
+let $ID= `SELECT @id := CONNECTION_ID()`;
+connection con2;
+let $ignore= `SELECT @id := $ID`;
+connection con1;
+SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
+disable_reconnect;
+SET DEBUG_SYNC= 'before_do_command_net_read SIGNAL in_sync WAIT_FOR kill';
+connection con2;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL @id;
+SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
+connection con1;
+--error 1053,2006,2013
+SELECT 1;
+enable_reconnect;
+SELECT 1;
+let $ignore= `SELECT @id := $ID`;
+SELECT @id != CONNECTION_ID();
+connection con2;
+SELECT 4;
+connection default;
+SET DEBUG_SYNC = 'RESET';
#
# BUG#14851: killing long running subquery processed via a temporary table.
#
-create table t1 (id int primary key);
-create table t2 (id int unsigned not null);
+CREATE TABLE t1 (id INT PRIMARY KEY AUTO_INCREMENT);
+CREATE TABLE t2 (id INT UNSIGNED NOT NULL);
-connect (conn1, localhost, root,,);
-connection conn1;
+INSERT INTO t1 VALUES
+(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0),
+(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0),
+(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0),
+(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0);
+INSERT t1 SELECT 0 FROM t1 AS a1, t1 AS a2 LIMIT 4032;
--- disable_result_log
--- disable_query_log
-let $1 = 4096;
-while ($1)
-{
- eval insert into t1 values ($1);
- dec $1;
-}
--- enable_query_log
--- enable_result_log
+INSERT INTO t2 SELECT id FROM t1;
+
+connection con1;
+let $ID= `SELECT @id := CONNECTION_ID()`;
+connection con2;
+let $ignore= `SELECT @id := $ID`;
-insert into t2 select id from t1;
+connection con1;
+SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
+SET DEBUG_SYNC= 'before_acos_function SIGNAL in_sync';
+# This is a very long running query. If this test start failing,
+# it may be necessary to change to an even longer query.
+send SELECT id FROM t1 WHERE id IN
+ (SELECT DISTINCT a.id FROM t2 a, t2 b, t2 c, t2 d
+ GROUP BY ACOS(1/a.id), b.id, c.id, d.id
+ HAVING a.id BETWEEN 10 AND 20);
-create table t3 (kill_id int);
-insert into t3 values(connection_id());
-connect (conn2, localhost, root,,);
-connection conn2;
-
-connection conn1;
--- disable_result_log
-# This is a very long running query. If this test start failing, it may
-# be necessary to change to an even longer query.
-send select id from t1 where id in (select distinct a.id from t2 a, t2 b, t2 c, t2 d group by a.id, b.id, c.id, d.id having a.id between 10 and 20);
--- enable_result_log
-
-connection conn2;
-select ((@id := kill_id) - kill_id) from t3;
--- sleep 1
-kill @id;
+connection con2;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL @id;
+SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
-connection conn1;
--- error 1053,2013
+connection con1;
+--error 1053,2006,2013
reap;
+SELECT 1;
connection default;
-
-drop table t1, t2, t3;
+SET DEBUG_SYNC = 'RESET';
+DROP TABLE t1, t2;
# End of 4.1 tests
#
-# test of blocking of sending ERROR after OK or EOF
+# Test of blocking of sending ERROR after OK or EOF
#
connection con1;
-select get_lock("a", 10);
+let $ID= `SELECT @id := CONNECTION_ID()`;
connection con2;
-let $ID= `select connection_id()`;
-send select get_lock("a", 10);
-real_sleep 2;
+let $ignore= `SELECT @id := $ID`;
connection con1;
-disable_query_log;
-eval kill query $ID;
-enable_query_log;
+SET DEBUG_SYNC= 'before_acos_function SIGNAL in_sync WAIT_FOR kill';
+send SELECT ACOS(0);
connection con2;
-reap;
-select 1;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
connection con1;
-select RELEASE_LOCK("a");
+reap;
+SELECT 1;
+SELECT @id = CONNECTION_ID();
+connection default;
+SET DEBUG_SYNC = 'RESET';
#
# Bug#27563: Stored functions and triggers wasn't throwing an error when killed.
#
-create table t1(f1 int);
+CREATE TABLE t1 (f1 INT);
delimiter |;
-create function bug27563() returns int(11)
-deterministic
-begin
- declare continue handler for sqlstate '70100' set @a:= 'killed';
- declare continue handler for sqlexception set @a:= 'exception';
- set @a= get_lock("lock27563", 10);
- return 1;
-end|
+CREATE FUNCTION bug27563() RETURNS INT(11)
+DETERMINISTIC
+BEGIN
+ DECLARE CONTINUE HANDLER FOR SQLSTATE '70100' SET @a:= 'killed';
+ DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+ SET DEBUG_SYNC= 'now SIGNAL in_sync WAIT_FOR kill';
+ RETURN 1;
+END|
delimiter ;|
# Test stored functions
# Test INSERT
connection con1;
-select get_lock("lock27563",10);
+let $ID= `SELECT @id := CONNECTION_ID()`;
connection con2;
-let $ID= `select connection_id()`;
-send insert into t1 values (bug27563());
-real_sleep 2;
-connection con1;
-disable_query_log;
-eval kill query $ID;
-enable_query_log;
+let $ignore= `SELECT @id := $ID`;
+connection con1;
+send INSERT INTO t1 VALUES (bug27563());
connection con2;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+connection con1;
--error 1317
reap;
-select @a;
-connection con1;
-select * from t1;
+SELECT * FROM t1;
+connection default;
+SET DEBUG_SYNC = 'RESET';
# Test UPDATE
-insert into t1 values(0);
-connection con2;
-send update t1 set f1= bug27563();
-real_sleep 2;
+INSERT INTO t1 VALUES(0);
connection con1;
-disable_query_log;
-eval kill query $ID;
-enable_query_log;
+send UPDATE t1 SET f1= bug27563();
connection con2;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+connection con1;
--error 1317
reap;
-select @a;
-connection con1;
-select * from t1;
+SELECT * FROM t1;
+connection default;
+SET DEBUG_SYNC = 'RESET';
# Test DELETE
-insert into t1 values(1);
-connection con2;
-send delete from t1 where bug27563() is null;
-real_sleep 2;
+INSERT INTO t1 VALUES(1);
connection con1;
-disable_query_log;
-eval kill query $ID;
-enable_query_log;
+send DELETE FROM t1 WHERE bug27563() IS NULL;
connection con2;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+connection con1;
--error 1317
reap;
-select @a;
-connection con1;
-select * from t1;
+SELECT * FROM t1;
+connection default;
+SET DEBUG_SYNC = 'RESET';
# Test SELECT
-connection con2;
-send select * from t1 where f1= bug27563();
-real_sleep 2;
connection con1;
-disable_query_log;
-eval kill query $ID;
-enable_query_log;
+send SELECT * FROM t1 WHERE f1= bug27563();
connection con2;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+connection con1;
--error 1317
reap;
-select @a;
+SELECT * FROM t1;
+connection default;
+SET DEBUG_SYNC = 'RESET';
+DROP FUNCTION bug27563;
# Test PROCEDURE
-connection con2;
delimiter |;
-create procedure proc27563()
-begin
- declare continue handler for sqlstate '70100' set @a:= 'killed';
- declare continue handler for sqlexception set @a:= 'exception';
- select get_lock("lock27563",10);
- select "shouldn't be selected";
-end|
+CREATE PROCEDURE proc27563()
+BEGIN
+ DECLARE CONTINUE HANDLER FOR SQLSTATE '70100' SET @a:= 'killed';
+ DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+ SELECT "should be selected" AS procedure_activity_1;
+ SET DEBUG_SYNC= 'now SIGNAL in_sync WAIT_FOR kill';
+ SELECT "shouldn't be selected" AS procedure_activity_2;
+END|
delimiter ;|
-send call proc27563();
-real_sleep 2;
connection con1;
-disable_query_log;
-eval kill query $ID;
-enable_query_log;
+send CALL proc27563();
connection con2;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+connection con1;
--error 1317
reap;
-select @a;
+SELECT * FROM t1;
+connection default;
+SET DEBUG_SYNC = 'RESET';
+DROP PROCEDURE proc27563;
# Test TRIGGERS
-connection con2;
-create table t2 (f2 int);
+CREATE TABLE t2 (f2 INT);
delimiter |;
-create trigger trg27563 before insert on t1 for each row
-begin
- declare continue handler for sqlstate '70100' set @a:= 'killed';
- declare continue handler for sqlexception set @a:= 'exception';
- set @a:= get_lock("lock27563",10);
- insert into t2 values(1);
-end|
+CREATE TRIGGER trg27563 BEFORE INSERT ON t1 FOR EACH ROW
+BEGIN
+ DECLARE CONTINUE HANDLER FOR SQLSTATE '70100' SET @a:= 'killed';
+ DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
+ INSERT INTO t2 VALUES(0);
+ SET DEBUG_SYNC= 'now SIGNAL in_sync WAIT_FOR kill';
+ INSERT INTO t2 VALUES(1);
+END|
delimiter ;|
-send insert into t1 values(2),(3);
-real_sleep 2;
connection con1;
-disable_query_log;
-eval kill query $ID;
-enable_query_log;
+send INSERT INTO t1 VALUES(2),(3);
connection con2;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+connection con1;
--error 1317
reap;
-select @a;
-connection con1;
-select * from t1;
-select * from t2;
-
-# Cleanup
-select release_lock("lock27563");
-drop table t1, t2;
-drop function bug27563;
-drop procedure proc27563;
+SELECT * FROM t1;
+SELECT * FROM t2;
+connection default;
+SET DEBUG_SYNC = 'RESET';
+DROP TABLE t1, t2;
#
# Bug#28598: mysqld crash when killing a long-running explain query.
#
---disable_query_log
connection con1;
-let $ID= `select connection_id()`;
+let $ID= `SELECT @id := CONNECTION_ID()`;
+connection con2;
+let $ignore= `SELECT @id := $ID`;
+connection con1;
+--disable_query_log
let $tab_count= 40;
let $i= $tab_count;
while ($i)
{
- eval CREATE TABLE t$i (a$i int, KEY(a$i));
+ eval CREATE TABLE t$i (a$i INT, KEY(a$i));
eval INSERT INTO t$i VALUES (1),(2),(3),(4),(5),(6),(7);
dec $i ;
}
-set session optimizer_search_depth=0;
+SET SESSION optimizer_search_depth=0;
let $i=$tab_count;
while ($i)
{
- let $a= a$i;
- let $t= t$i;
- dec $i;
- if ($i)
- {
- let $comma=,;
- let $from=$comma$t$from;
- let $where=a$i=$a $and $where;
- }
- if (!$i)
- {
- let $from=FROM $t$from;
- let $where=WHERE $where;
- }
- let $and=AND;
+ let $a= a$i;
+ let $t= t$i;
+ dec $i;
+ if ($i)
+ {
+ let $comma=,;
+ let $from=$comma$t$from;
+ let $where=a$i=$a $and $where;
+ }
+ if (!$i)
+ {
+ let $from=FROM $t$from;
+ let $where=WHERE $where;
+ }
+ let $and=AND;
}
--enable_query_log
+SET DEBUG_SYNC= 'before_join_optimize SIGNAL in_sync';
eval PREPARE stmt FROM 'EXPLAIN SELECT * $from $where';
send EXECUTE stmt;
---disable_query_log
connection con2;
-real_sleep 2;
-eval kill query $ID;
+SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
+KILL QUERY @id;
+connection con1;
+--error 1317
+reap;
+--disable_query_log
let $i= $tab_count;
while ($i)
{
@@ -308,8 +316,8 @@ while ($i)
dec $i ;
}
--enable_query_log
-
-###########################################################################
+connection default;
+SET DEBUG_SYNC = 'RESET';
--echo #
--echo # Bug#19723: kill of active connection yields different error code
@@ -317,16 +325,26 @@ while ($i)
--echo #
--echo
---echo # Connection: con2.
---connection con2
-
-KILL CONNECTION_ID();
+--echo # Connection: con1.
+--connection con1
+let $ID= `SELECT @id := CONNECTION_ID()`;
+SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
+--disable_reconnect
+KILL @id;
---echo # CR_SERVER_LOST, CR_SERVER_GONE_ERROR, depending on the timing
---echo # of close of the connection socket
---error 2013, 2006
+connection con2;
+SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
+connection con1;
+--echo # ER_SERVER_SHUTDOWN, CR_SERVER_GONE_ERROR, CR_SERVER_LOST,
+--echo # depending on the timing of close of the connection socket
+--error 1053,2006,2013
+SELECT 1;
+--enable_reconnect
SELECT 1;
---connection default
+let $ignore= `SELECT @id := $ID`;
+SELECT @id != CONNECTION_ID();
+connection default;
+SET DEBUG_SYNC = 'RESET';
###########################################################################
#
@@ -571,5 +589,3 @@ SELECT 1;
#
###########################################################################
-# Restore global concurrent_insert value. Keep in the end of the test file.
-set @@global.concurrent_insert= @old_concurrent_insert;
=== modified file 'sql/event_queue.cc'
--- a/sql/event_queue.cc 2008-12-04 21:02:09 +0000
+++ b/sql/event_queue.cc 2009-05-13 13:22:15 +0000
@@ -742,11 +742,14 @@ Event_queue::cond_wait(THD *thd, struct
thd->enter_cond(&COND_queue_state, &LOCK_event_queue, msg);
- DBUG_PRINT("info", ("pthread_cond_%swait", abstime? "timed":""));
- if (!abstime)
- pthread_cond_wait(&COND_queue_state, &LOCK_event_queue);
- else
- pthread_cond_timedwait(&COND_queue_state, &LOCK_event_queue, abstime);
+ if (!thd->killed)
+ {
+ DBUG_PRINT("info", ("pthread_cond_%swait", abstime? "timed":""));
+ if (!abstime)
+ pthread_cond_wait(&COND_queue_state, &LOCK_event_queue);
+ else
+ pthread_cond_timedwait(&COND_queue_state, &LOCK_event_queue, abstime);
+ }
mutex_last_locked_in_func= func;
mutex_last_locked_at_line= line;
=== modified file 'sql/lock.cc'
--- a/sql/lock.cc 2009-03-18 21:22:12 +0000
+++ b/sql/lock.cc 2009-05-13 13:22:15 +0000
@@ -1128,6 +1128,14 @@ bool lock_global_read_lock(THD *thd)
const char *new_message= "Waiting to get readlock";
(void) pthread_mutex_lock(&LOCK_global_read_lock);
+ old_message= thd->enter_cond(&COND_global_read_lock,
+ &LOCK_global_read_lock, new_message);
+ DBUG_PRINT("info",
+ ("waiting_for: %d protect_against: %d",
+ waiting_for_read_lock, protect_against_global_read_lock));
+
+ waiting_for_read_lock++;
+
#if defined(ENABLED_DEBUG_SYNC)
/*
The below sync point fires if we have to wait for
@@ -1136,27 +1144,18 @@ bool lock_global_read_lock(THD *thd)
WARNING: Beware to use WAIT_FOR with this sync point. We hold
LOCK_global_read_lock here.
- Call the sync point before calling enter_cond() as it does use
- enter_cond() and exit_cond() itself if a WAIT_FOR action is
- executed in spite of the above warning.
+ The sync point is after enter_cond() so that proc_info is
+ available immediately after the sync point sends a SIGNAL. This
+ can make tests more reliable.
- Pre-set proc_info so that it is available immediately after the
- sync point sends a SIGNAL. This makes tests more reliable.
+ The sync point is before the loop so that it is executed once only.
*/
- if (protect_against_global_read_lock)
+ if (protect_against_global_read_lock && !thd->killed)
{
- thd_proc_info(thd, new_message);
DEBUG_SYNC(thd, "wait_lock_global_read_lock");
}
#endif /* defined(ENABLED_DEBUG_SYNC) */
- old_message=thd->enter_cond(&COND_global_read_lock, &LOCK_global_read_lock,
- new_message);
- DBUG_PRINT("info",
- ("waiting_for: %d protect_against: %d",
- waiting_for_read_lock, protect_against_global_read_lock));
-
- waiting_for_read_lock++;
while (protect_against_global_read_lock && !thd->killed)
pthread_cond_wait(&COND_global_read_lock, &LOCK_global_read_lock);
waiting_for_read_lock--;
@@ -1272,6 +1271,9 @@ bool wait_if_global_read_lock(THD *thd,
DBUG_RETURN(is_not_commit);
}
+ old_message= thd->enter_cond(&COND_global_read_lock,
+ &LOCK_global_read_lock, new_message);
+
#if defined(ENABLED_DEBUG_SYNC)
/*
The below sync point fires if we have to wait for
@@ -1280,22 +1282,19 @@ bool wait_if_global_read_lock(THD *thd,
WARNING: Beware to use WAIT_FOR with this sync point. We hold
LOCK_global_read_lock here.
- Call the sync point before calling enter_cond() as it does use
- enter_cond() and exit_cond() itself if a WAIT_FOR action is
- executed in spite of the above warning.
+ The sync point is after enter_cond() so that proc_info is
+ available immediately after the sync point sends a SIGNAL. This
+ can make tests more reliable.
- Pre-set proc_info so that it is available immediately after the
- sync point sends a SIGNAL. This makes tests more reliable.
+ The sync point is before the loop so that it is executed once only.
*/
- if (must_wait)
+ if (must_wait && ! thd->killed &&
+ (!abort_on_refresh || thd->version == refresh_version))
{
- thd_proc_info(thd, new_message);
DEBUG_SYNC(thd, "wait_if_global_read_lock");
}
#endif /* defined(ENABLED_DEBUG_SYNC) */
- old_message=thd->enter_cond(&COND_global_read_lock, &LOCK_global_read_lock,
- new_message);
while (must_wait && ! thd->killed &&
(!abort_on_refresh || thd->version == refresh_version))
{
=== modified file 'sql/mdl.cc'
--- a/sql/mdl.cc 2009-03-31 13:00:58 +0000
+++ b/sql/mdl.cc 2009-05-13 13:22:15 +0000
@@ -533,8 +533,6 @@ static inline void mdl_exit_cond(THD *th
mysys_var->current_cond= 0;
pthread_mutex_unlock(&mysys_var->mutex);
- DEBUG_SYNC(thd, "mdl_exit_cond");
-
(void) set_thd_proc_info(thd, old_msg, calling_func,
calling_file, calling_line);
}
=== modified file 'sql/slave.cc'
--- a/sql/slave.cc 2009-04-13 13:24:28 +0000
+++ b/sql/slave.cc 2009-05-13 13:22:15 +0000
@@ -718,9 +718,17 @@ int start_slave_thread(pthread_handler h
while (start_id == *slave_run_id)
{
DBUG_PRINT("sleep",("Waiting for slave thread to start"));
- const char* old_msg = thd->enter_cond(start_cond,cond_lock,
- "Waiting for slave thread to start");
- pthread_cond_wait(start_cond,cond_lock);
+ const char* old_msg= thd->enter_cond(start_cond, cond_lock,
+ "Waiting for slave thread to start");
+ /*
+ It is not sufficient to test this at loop bottom. We must test
+ it after registering the mutex in enter_cond(). If the kill
+ happens after testing of thd->killed and before the mutex is
+ registered, we could otherwise go waiting though thd->killed is
+ set.
+ */
+ if (!thd->killed)
+ pthread_cond_wait(start_cond, cond_lock);
thd->exit_cond(old_msg);
pthread_mutex_lock(cond_lock); // re-acquire it as exit_cond() released
if (thd->killed)
@@ -2418,9 +2426,7 @@ static int try_to_reconnect(THD *thd, MY
{
mi->slave_running= MYSQL_SLAVE_RUN_NOT_CONNECT;
thd->proc_info= messages[SLAVE_RECON_MSG_WAIT];
-#ifdef SIGNAL_WITH_VIO_CLOSE
thd->clear_active_vio();
-#endif
end_server(mysql);
if ((*retry_count)++)
{
@@ -2760,9 +2766,7 @@ err:
can be called in the middle of closing the VIO associated with
the 'mysql' object, causing a crash.
*/
-#ifdef SIGNAL_WITH_VIO_CLOSE
thd->clear_active_vio();
-#endif
mysql_close(mysql);
mi->mysql=0;
}
@@ -3884,9 +3888,7 @@ replication resumed in log '%s' at posit
general_log_print(thd, COM_CONNECT_OUT, "%s@%s:%d",
mi->user, mi->host, mi->port);
}
-#ifdef SIGNAL_WITH_VIO_CLOSE
thd->set_active_vio(mysql->net.vio);
-#endif
}
mysql->reconnect= 1;
DBUG_PRINT("exit",("slave_was_killed: %d", slave_was_killed));
=== modified file 'sql/sql_base.cc'
--- a/sql/sql_base.cc 2009-04-03 15:14:49 +0000
+++ b/sql/sql_base.cc 2009-05-13 13:22:15 +0000
@@ -1024,7 +1024,7 @@ bool close_cached_tables(THD *thd, TABLE
}
}
- if (found)
+ if (found && ! thd->killed)
{
DBUG_PRINT("signal", ("Waiting for COND_refresh"));
pthread_cond_wait(&COND_refresh,&LOCK_open);
@@ -7770,7 +7770,16 @@ static bool tdc_wait_for_old_versions(TH
break;
}
old_msg= thd->enter_cond(&COND_refresh, &LOCK_open, "Waiting for table");
- pthread_cond_wait(&COND_refresh, &LOCK_open);
+ if (!thd->killed)
+ {
+ /*
+ The sync point is after enter_cond() so that proc_info is
+ available immediately after the sync point sends a SIGNAL. This
+ can make tests more reliable.
+ */
+ DEBUG_SYNC(thd, "tdc_wait_for_table");
+ pthread_cond_wait(&COND_refresh, &LOCK_open);
+ }
/* LOCK_open mutex is unlocked by THD::exit_cond() as side-effect. */
thd->exit_cond(old_msg);
}
=== modified file 'sql/sql_class.cc'
--- a/sql/sql_class.cc 2009-04-03 15:14:49 +0000
+++ b/sql/sql_class.cc 2009-05-13 13:22:15 +0000
@@ -495,9 +495,7 @@ THD::THD()
&variables.wt_timeout_short,
&variables.wt_deadlock_search_depth_long,
&variables.wt_timeout_long);
-#ifdef SIGNAL_WITH_VIO_CLOSE
active_vio = 0;
-#endif
pthread_mutex_init(&LOCK_delete, MY_MUTEX_INIT_FAST);
/* Variables with default values */
@@ -1132,36 +1130,72 @@ void add_diff_to_status(STATUS_VAR *to_v
#endif
+/**
+ Awake a thread.
+
+ @param[in] state_to_set value for THD::killed
+
+ This is normally called from another thread's THD object.
+
+ @note Do always call this while holding LOCK_delete.
+*/
+
void THD::awake(THD::killed_state state_to_set)
{
DBUG_ENTER("THD::awake");
- DBUG_PRINT("enter", ("this: %p", this));
+ DBUG_PRINT("enter", ("this: %p current_thd: %p", this, current_thd));
THD_CHECK_SENTRY(this);
- safe_mutex_assert_owner(&LOCK_delete);
+ safe_mutex_assert_owner(&LOCK_delete);
+ /*
+ Set the 'killed' flag of 'this', which is the target THD object.
+ */
killed= state_to_set;
+
if (state_to_set != THD::KILL_QUERY)
{
- thr_alarm_kill(thread_id);
- if (!slave_thread)
- thread_scheduler.post_kill_notification(this);
-#ifdef SIGNAL_WITH_VIO_CLOSE
if (this != current_thd)
{
/*
- In addition to a signal, let's close the socket of the thread that
- is being killed. This is to make sure it does not block if the
- signal is lost. This needs to be done only on platforms where
- signals are not a reliable interruption mechanism.
-
- If we're killing ourselves, we know that we're not blocked, so this
- hack is not used.
+ Before sending a signal, let's close the socket of the thread
+ that is being killed ("this", which is not the current thread).
+ This is to make sure it does not block if the signal is lost.
+ Another reason is that the target thread might not wait on the
+ socket at the moment when we send the signal. It might come
+ later to the blocking point. The closed connection prevents it
+ from blocking.
+
+ If we are killing ourselves, we know that we are not blocked.
+ We also know that we will check thd->killed before we go for
+ reading the next statement.
*/
close_active_vio();
}
-#endif
+
+ /*
+ Mark the target thread's alarm request expired, and signal alarm.
+ This is done after closing the socket to avoid a possible race
+ condition. If the target thread did already pass the last check of
+ thd->killed but has not yet arrived in read(2), the signal would
+ not affect it. It could still run into read(2). But As we have
+ already closed the socket, read(2) will fail immediately.
+
+ If we reverse the two operations, the target thread could go into
+ read(2) after the alarm signal came in and before the socket is
+ closed. The closing operation itself might not awake the target
+ thread on all platforms.
+ */
+ thr_alarm_kill(thread_id);
+
+ /* Send an event to "libevent" that a thread should be killed. */
+ if (!slave_thread)
+ thread_scheduler.post_kill_notification(this);
}
+
+ /*
+ Broadcast a condition to kick the target if it is waiting on it.
+ */
if (mysys_var)
{
pthread_mutex_lock(&mysys_var->mutex);
@@ -1187,6 +1221,11 @@ void THD::awake(THD::killed_state state_
It's true that we have set its thd->killed but it may not
see it immediately and so may have time to reach the cond_wait().
+ However, where possible, we test for killed once again after
+ enter_cond(). This should make the signalling as safe as possible.
+ However, there is still a small chance of failure on platforms with
+ instuction or memory write reordering.
+
We have to do the loop with trylock, because if we would use
pthread_mutex_lock(), we can cause a deadlock as we are here locking
the mysys_var->mutex and mysys_var->current_mutex in a different order
@@ -1194,7 +1233,7 @@ void THD::awake(THD::killed_state state_
We only sleep for 2 seconds as we don't want to have LOCK_delete
locked too long time.
- There is a small change we may not succeed in aborting a thread that
+ There is a small chance we may not succeed in aborting a thread that
is not yet waiting for a mutex, but as this happens only for a
thread that was doing something else when the kill was issued and
which should detect the kill flag before it starts to wait, this
@@ -1576,7 +1615,7 @@ int THD::send_explain_fields(select_resu
Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF));
}
-#ifdef SIGNAL_WITH_VIO_CLOSE
+
void THD::close_active_vio()
{
DBUG_ENTER("close_active_vio");
@@ -1590,7 +1629,6 @@ void THD::close_active_vio()
#endif
DBUG_VOID_RETURN;
}
-#endif
struct Item_change_record: public ilink
=== modified file 'sql/sql_class.h'
--- a/sql/sql_class.h 2009-04-14 23:53:44 +0000
+++ b/sql/sql_class.h 2009-05-13 13:22:15 +0000
@@ -1485,9 +1485,7 @@ public:
#ifndef __WIN__
sigset_t signals;
#endif
-#ifdef SIGNAL_WITH_VIO_CLOSE
Vio* active_vio;
-#endif
/*
This is to track items changed during execution of a prepared
statement/stored procedure. It's created by
@@ -1715,6 +1713,12 @@ public:
DYNAMIC_ARRAY user_var_events; /* For user variables replication */
MEM_ROOT *user_var_events_alloc; /* Allocate above array elements here */
+ /*
+ If checking this in conjunction with a wait condition, please
+ include a check after enter_cond() if you want to avoid a race
+ condition. For details see the implementation of awake(),
+ especially the "broadcast" part.
+ */
enum killed_state
{
NOT_KILLED=0,
@@ -1903,7 +1907,6 @@ public:
void cleanup(void);
void cleanup_after_query();
bool store_globals();
-#ifdef SIGNAL_WITH_VIO_CLOSE
inline void set_active_vio(Vio* vio)
{
pthread_mutex_lock(&LOCK_delete);
@@ -1917,7 +1920,6 @@ public:
pthread_mutex_unlock(&LOCK_delete);
}
void close_active_vio();
-#endif
void awake(THD::killed_state state_to_set);
#ifndef MYSQL_CLIENT
=== modified file 'sql/sql_connect.cc'
--- a/sql/sql_connect.cc 2009-03-17 20:26:16 +0000
+++ b/sql/sql_connect.cc 2009-05-13 13:22:15 +0000
@@ -661,9 +661,7 @@ static int check_connection(THD *thd)
DBUG_PRINT("info",
("New connection received on %s", vio_description(net->vio)));
-#ifdef SIGNAL_WITH_VIO_CLOSE
thd->set_active_vio(net->vio);
-#endif
if (!thd->main_security_ctx.host) // If TCP/IP connection
{
=== modified file 'sql/sql_parse.cc'
--- a/sql/sql_parse.cc 2009-04-22 22:12:25 +0000
+++ b/sql/sql_parse.cc 2009-05-13 13:22:15 +0000
@@ -674,6 +674,22 @@ bool do_command(THD *thd)
net_new_transaction(net);
+ /*
+ Synchronization point for testing of KILL_CONNECTION.
+ This sync point can wait here, to simulate slow code execution
+ between the last test of thd->killed and blocking in read().
+
+ The goal of this test is to verify that a connection does not
+ hang, if it is killed at this point of execution.
+ (Bug#37780 - main.kill fails randomly)
+
+ Note that the sync point wait itself will be terminated by a
+ kill. In this case it consumes a condition broadcast, but does
+ not change anything else. The consumed broadcast should not
+ matter here, because the read/recv() below doesn't use it.
+ */
+ DEBUG_SYNC(thd, "before_do_command_net_read");
+
if ((packet_length= my_net_read(net)) == packet_error)
{
DBUG_PRINT("info",("Got error %d reading command from socket %s",
=== modified file 'sql/sql_select.cc'
--- a/sql/sql_select.cc 2009-04-13 09:51:24 +0000
+++ b/sql/sql_select.cc 2009-05-13 13:22:15 +0000
@@ -29,6 +29,7 @@
#endif
#include "mysql_priv.h"
+#include "debug_sync.h"
#include "sql_select.h"
#include "sql_cursor.h"
@@ -1416,6 +1417,7 @@ JOIN::optimize()
if (optimized)
DBUG_RETURN(0);
optimized= 1;
+ DEBUG_SYNC(thd, "before_join_optimize");
thd_proc_info(thd, "optimizing");
=== modified file 'vio/viosocket.c'
--- a/vio/viosocket.c 2009-03-17 20:07:27 +0000
+++ b/vio/viosocket.c 2009-05-13 13:22:15 +0000
@@ -277,8 +277,10 @@ int vio_close(Vio * vio)
DBUG_ASSERT(vio->sd >= 0);
if (shutdown(vio->sd, SHUT_RDWR))
r= -1;
+ DBUG_PRINT("vio", ("shut down socket: %d", vio->sd));
if (closesocket(vio->sd))
r= -1;
+ DBUG_PRINT("vio", ("closed socket: %d", vio->sd));
}
if (r)
{
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