mariadb/mysql-test/t/flush.test
unknown 719e64e4a5 Bug#32528 Global read lock with a low priority write lock causes a server crash
FLUSH TABLES WITH READ LOCK fails to properly detect write locked
tables when running under low priority updates.

The problem is that when trying to aspire a global read lock, the
reload_acl_and_cache() function fails to properly check if the thread
has a low priority write lock, which later my cause a server crash or
deadlock.

The solution is to simple check if the thread has any type of the
possible exclusive write locks.


mysql-test/r/flush.result:
  Add test case result for Bug#32528
mysql-test/t/flush.test:
  Add test case for Bug#32528
sql/sql_parse.cc:
  Although it should not matter under LOCK TABLES, use TL_WRITE_ALLOW_WRITE
  to emphasize that it should fail in case of any write lock.
2007-11-22 10:18:19 -02:00

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3.4 KiB
Text

connect (con1,localhost,root,,);
connect (con2,localhost,root,,);
connection con1;
--disable_warnings
drop table if exists t1,t2;
drop database if exists mysqltest;
--enable_warnings
create temporary table t1(n int not null primary key);
create table t2(n int);
insert into t2 values(3);
let $1=100;
disable_query_log;
while ($1)
{
connection con1;
send replace into t1 select n from t2;
connection con2;
send flush tables;
connection con1;
reap;
connection con2;
reap;
dec $1;
}
enable_query_log;
connection con1;
select * from t1;
connection con2;
flush tables with read lock;
--error 1223
drop table t2;
connection con1;
send drop table t2;
connection con2;
unlock tables;
connection con1;
reap;
#test if drop database will wait until we release the global read lock
connection con1;
create database mysqltest;
create table mysqltest.t1(n int);
insert into mysqltest.t1 values (23);
flush tables with read lock;
connection con2;
send drop database mysqltest;
connection con1;
select * from mysqltest.t1;
unlock tables;
connection con2;
reap;
# test if dirty close releases global read lock
connection con1;
create table t1 (n int);
flush tables with read lock;
dirty_close con1;
connection con2;
insert into t1 values (345);
select * from t1;
drop table t1;
#
# Bug#9459 - deadlock with flush with lock, and lock table write
#
create table t1 (c1 int);
lock table t1 write;
# Cannot get the global read lock with write locked tables.
--error 1192
flush tables with read lock;
lock table t1 read;
# Can get the global read lock with read locked tables.
flush tables with read lock;
--error 1223
lock table t1 write;
lock table t1 read;
--error 1223
lock table t1 write;
# Release all table locks and the global read lock.
unlock tables;
create table t2 (c1 int);
create table t3 (c1 int);
lock table t1 read, t2 read, t3 write;
# Cannot get the global read lock with write locked tables.
--error 1192
flush tables with read lock;
lock table t1 read, t2 read, t3 read;
# Can get the global read lock with read locked tables.
flush tables with read lock;
# Release all table locks and the global read lock.
unlock tables;
drop table t1, t2, t3;
# End of 4.1 tests
#
# Test of deadlock problem when doing FLUSH TABLE with read lock
# (Bug was in NTPL threads in Linux when using different mutex while
# waiting for a condtion variable)
create table t1 (c1 int);
create table t2 (c1 int);
connect (con1,localhost,root,,);
connect (con3,localhost,root,,);
connection con1;
lock table t1 write;
connection con2;
send flush tables with read lock;
--sleep 1
connection con3;
send insert into t2 values(1);
--sleep 1
connection con1;
unlock tables;
disconnect con1;
connection con2;
reap;
disconnect con2;
connection con3;
# It hangs here (insert into t2 does not end).
reap;
disconnect con3;
connection default;
drop table t1, t2;
#
# Bug#32528 Global read lock with a low priority write lock causes a server crash
#
--disable_warnings
drop table if exists t1, t2;
--enable_warnings
set session low_priority_updates=1;
create table t1 (a int);
create table t2 (b int);
lock tables t1 write;
--error ER_LOCK_OR_ACTIVE_TRANSACTION
flush tables with read lock;
unlock tables;
lock tables t1 read, t2 write;
--error ER_LOCK_OR_ACTIVE_TRANSACTION
flush tables with read lock;
unlock tables;
lock tables t1 read;
flush tables with read lock;
unlock tables;
drop table t1, t2;
set session low_priority_updates=default;
# End of 5.0 tests