mariadb/mysql-test/t/schema.test
Jon Olav Hauglid b4593605e0 Bug #54360 Deadlock DROP/ALTER/CREATE DATABASE with open HANDLER
This deadlock happened if DROP DATABASE was blocked due to an open
HANDLER table from a different connection. While DROP DATABASE
is blocked, it holds the LOCK_mysql_create_db mutex. This results
in a deadlock if the connection with the open HANDLER table tries
to execute a CREATE/ALTER/DROP DATABASE statement as they all
try to acquire LOCK_mysql_create_db.

This patch makes this deadlock scenario very unlikely by closing and
marking for re-open all HANDLER tables for which there are pending
conflicing locks, before LOCK_mysql_create_db is acquired.
However, there is still a very slight possibility that a connection
could access one of these HANDLER tables between closing/marking for
re-open and the acquisition of LOCK_mysql_create_db.

This patch is for 5.1 only, a separate and complete fix will be
made for 5.5+.

Test case added to schema.test.
2010-06-26 19:36:00 +02:00

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#
# Just a couple of tests to make sure that schema works.
#
# Drop mysqltest1 database, as it can left from the previous tests.
#
# Save the initial number of concurrent sessions.
--source include/count_sessions.inc
--disable_warnings
drop database if exists mysqltest1;
--enable_warnings
create schema foo;
show create schema foo;
show schemas;
drop schema foo;
--echo #
--echo # Bug#54360 Deadlock DROP/ALTER/CREATE DATABASE with open HANDLER
--echo #
CREATE DATABASE db1;
CREATE TABLE db1.t1 (a INT);
INSERT INTO db1.t1 VALUES (1), (2);
--echo # Connection con1
connect (con1, localhost, root);
HANDLER db1.t1 OPEN;
--echo # Connection default
connection default;
--echo # Sending:
--send DROP DATABASE db1
--echo # Connection con2
connect (con2, localhost, root);
--echo # Waiting for 'DROP DATABASE db1' to sync in.
let $wait_condition=SELECT COUNT(*)=1 FROM information_schema.processlist
WHERE state='Waiting for table' AND info='DROP DATABASE db1';
--source include/wait_condition.inc
--echo # Connection con1
connection con1;
# All these statements before resulted in deadlock.
CREATE DATABASE db2;
ALTER DATABASE db2 DEFAULT CHARACTER SET utf8;
DROP DATABASE db2;
--echo # Connection default
connection default;
--echo # Reaping: DROP DATABASE db1
--reap
disconnect con1;
disconnect con2;
# 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