Below is the list of changes that have just been committed into a local
5.1 repository of ram. When ram does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
For information on how to access the public repository
see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html
ChangeSet@stripped, 2007-06-15 19:11:10+05:00, ramil@stripped +5 -0
Fix for bug #26380: LOCK TABLES + FLUSH LOGS causes deadlock
Problem: flushing logs we may hit a deadlock if the GLOBAL READ LOCK was
accuired before, as the logger calls wait_if_global_read_lock() for the
logging thread that is not an owner of the GLOBAL READ LOCK.
Fix: the logger shouldn't honor the GLOBAL READ LOCK flushing its tables.
mysql-test/r/flush.result@stripped, 2007-06-15 19:11:07+05:00, ramil@stripped +16 -0
Fix for bug #26380: LOCK TABLES + FLUSH LOGS causes deadlock
- test result.
mysql-test/t/flush.test@stripped, 2007-06-15 19:11:07+05:00, ramil@stripped +25 -1
Fix for bug #26380: LOCK TABLES + FLUSH LOGS causes deadlock
- test case.
sql/lock.cc@stripped, 2007-06-15 19:11:07+05:00, ramil@stripped +1 -3
Fix for bug #26380: LOCK TABLES + FLUSH LOGS causes deadlock
- logger.is_privileged_thread() used.
sql/log.h@stripped, 2007-06-15 19:11:07+05:00, ramil@stripped +6 -0
Fix for bug #26380: LOCK TABLES + FLUSH LOGS causes deadlock
- LOGGER::is_privileged_thread() introduced that returns TRUE if a given thread
is either a general_log or a slow_log or a privileged thread.
sql/sql_base.cc@stripped, 2007-06-15 19:11:07+05:00, ramil@stripped +6 -2
Fix for bug #26380: LOCK TABLES + FLUSH LOGS causes deadlock
- pass MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK to the mysql_lock_tables() in case of
call from a logger in order not to honor the GLOBAL READ LOCK
and to avoid possible deadlocks.
# This is a BitKeeper patch. What follows are the unified diffs for the
# set of deltas contained in the patch. The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User: ramil
# Host: ramil.myoffice.izhnet.ru
# Root: /home/ram/work/b26380/b26380.5.1
--- 1.108/sql/lock.cc 2007-06-15 19:11:16 +05:00
+++ 1.109/sql/lock.cc 2007-06-15 19:11:16 +05:00
@@ -707,9 +707,7 @@ static MYSQL_LOCK *get_lock_data(THD *th
if (!table_ptr[i]-> file->
check_if_locking_is_allowed(thd->lex->sql_command, thd->lex->type,
table_ptr[i], count, i, &system_count,
- (thd == logger.get_general_log_thd()) ||
- (thd == logger.get_slow_log_thd()) ||
- (thd == logger.get_privileged_thread())))
+ logger.is_privileged_thread(thd)))
DBUG_RETURN(0);
}
--- 1.408/sql/sql_base.cc 2007-06-15 19:11:16 +05:00
+++ 1.409/sql/sql_base.cc 2007-06-15 19:11:16 +05:00
@@ -4018,6 +4018,11 @@ int lock_tables(THD *thd, TABLE_LIST *ta
{
DBUG_ASSERT(thd->lock == 0); // You must lock everything at once
TABLE **start,**ptr;
+ uint lock_flag= MYSQL_LOCK_NOTIFY_IF_NEED_REOPEN;
+
+ /* Don't honor the GLOBAL READ LOCK if called from a logger */
+ if (logger.is_privileged_thread(thd))
+ lock_flag|= MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK;
if (!(ptr=start=(TABLE**) thd->alloc(sizeof(TABLE*)*count)))
DBUG_RETURN(-1);
@@ -4046,8 +4051,7 @@ int lock_tables(THD *thd, TABLE_LIST *ta
}
if (! (thd->lock= mysql_lock_tables(thd, start, (uint) (ptr - start),
- MYSQL_LOCK_NOTIFY_IF_NEED_REOPEN,
- need_reopen)))
+ lock_flag, need_reopen)))
{
if (thd->lex->requires_prelocking())
{
--- 1.25/sql/log.h 2007-06-15 19:11:16 +05:00
+++ 1.26/sql/log.h 2007-06-15 19:11:16 +05:00
@@ -600,6 +600,12 @@ public:
else
return NULL;
}
+ bool is_privileged_thread(THD *thd)
+ {
+ return thd == get_general_log_thd() ||
+ thd == get_slow_log_thd() ||
+ thd == get_privileged_thread();
+ }
};
enum enum_binlog_format {
--- 1.16/mysql-test/r/flush.result 2007-06-15 19:11:16 +05:00
+++ 1.17/mysql-test/r/flush.result 2007-06-15 19:11:16 +05:00
@@ -55,3 +55,19 @@ flush tables with read lock;
insert into t2 values(1);
unlock tables;
drop table t1, t2;
+End of 5.0 tests
+set @old_general_log= @@general_log;
+set @old_read_only= @@read_only;
+set global general_log= on;
+flush tables with read lock;
+flush logs;
+unlock tables;
+set global read_only=1;
+flush logs;
+unlock tables;
+flush tables with read lock;
+flush logs;
+unlock tables;
+set global general_log= @old_general_log;
+set global read_only= @old_read_only;
+End of 5.1 tests
--- 1.23/mysql-test/t/flush.test 2007-06-15 19:11:16 +05:00
+++ 1.24/mysql-test/t/flush.test 2007-06-15 19:11:16 +05:00
@@ -133,4 +133,28 @@ disconnect con3;
connection default;
drop table t1, t2;
-# End of 5.0 tests
+--echo End of 5.0 tests
+
+#
+# Bug #26380: LOCK TABLES + FLUSH LOGS causes deadlock
+#
+set @old_general_log= @@general_log;
+set @old_read_only= @@read_only;
+set global general_log= on;
+
+flush tables with read lock;
+flush logs;
+unlock tables;
+
+set global read_only=1;
+flush logs;
+unlock tables;
+
+flush tables with read lock;
+flush logs;
+unlock tables;
+
+set global general_log= @old_general_log;
+set global read_only= @old_read_only;
+
+--echo End of 5.1 tests
