mariadb/mysql-test/r/schema.result
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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drop database if exists mysqltest1;
create schema foo;
show create schema foo;
Database Create Database
foo CREATE DATABASE `foo` /*!40100 DEFAULT CHARACTER SET latin1 */
show schemas;
Database
information_schema
foo
mtr
mysql
test
drop schema foo;
#
# Bug#54360 Deadlock DROP/ALTER/CREATE DATABASE with open HANDLER
#
CREATE DATABASE db1;
CREATE TABLE db1.t1 (a INT);
INSERT INTO db1.t1 VALUES (1), (2);
# Connection con1
HANDLER db1.t1 OPEN;
# Connection default
# Sending:
DROP DATABASE db1;
# Connection con2
# Waiting for 'DROP DATABASE db1' to sync in.
# Connection con1
CREATE DATABASE db2;
ALTER DATABASE db2 DEFAULT CHARACTER SET utf8;
DROP DATABASE db2;
# Connection default
# Reaping: DROP DATABASE db1