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Bug #57663 Concurrent statement using stored function and DROP DATABASE

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breaks SBR

This pre-requisite patch refactors the code for dropping tables, used
by DROP TABLE and DROP DATABASE. The patch moves the code for acquiring
metadata locks out of mysql_rm_table_part2() and makes it the
responsibility of the caller. This in preparation of changing the
DROP DATABASE implementation to acquire all metadata locks before any
changes are made. mysql_rm_table_part2() is renamed
mysql_rm_table_no_locks() to reflect the change.
This commit is contained in:
Jon Olav Hauglid
2010-11-16 11:00:12 +01:00
parent 0caa22b145
commit 0ef8d8e26c
5 changed files with 158 additions and 110 deletions
Download Patch File Download Diff File Expand all files Collapse all files

207
sql/sql_table.cc
View File

@ -1849,12 +1849,77 @@ bool mysql_rm_table(THD *thd,TABLE_LIST *tables, my_bool if_exists,
{
bool error;
Drop_table_error_handler err_handler;
TABLE_LIST *table;
DBUG_ENTER("mysql_rm_table");
/* Disable drop of enabled log tables, must be done before name locking */
for (table= tables; table; table= table->next_local)
{
if (check_if_log_table(table->db_length, table->db,
table->table_name_length, table->table_name, true))
{
my_error(ER_BAD_LOG_STATEMENT, MYF(0), "DROP");
DBUG_RETURN(true);
}
}
mysql_ha_rm_tables(thd, tables);
if (!drop_temporary)
{
if (!thd->locked_tables_mode)
{
if (lock_table_names(thd, tables, NULL, thd->variables.lock_wait_timeout,
MYSQL_OPEN_SKIP_TEMPORARY))
DBUG_RETURN(true);
for (table= tables; table; table= table->next_local)
tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table->db, table->table_name,
false);
}
else
{
for (table= tables; table; table= table->next_local)
if (table->open_type != OT_BASE_ONLY &&
find_temporary_table(thd, table))
{
/*
A temporary table.
Don't try to find a corresponding MDL lock or assign it
to table->mdl_request.ticket. There can't be metadata
locks for temporary tables: they are local to the session.
Later in this function we release the MDL lock only if
table->mdl_requeset.ticket is not NULL. Thus here we
ensure that we won't release the metadata lock on the base
table locked with LOCK TABLES as a side effect of temporary
table drop.
*/
DBUG_ASSERT(table->mdl_request.ticket == NULL);
}
else
{
/*
Not a temporary table.
Since 'tables' list can't contain duplicates (this is ensured
by parser) it is safe to cache pointer to the TABLE instances
in its elements.
*/
table->table= find_table_for_mdl_upgrade(thd->open_tables, table->db,
table->table_name, false);
if (!table->table)
DBUG_RETURN(true);
table->mdl_request.ticket= table->table->mdl_ticket;
}
}
}
/* mark for close and remove all cached entries */
thd->push_internal_handler(&err_handler);
error= mysql_rm_table_part2(thd, tables, if_exists, drop_temporary, 0, 0);
error= mysql_rm_table_no_locks(thd, tables, if_exists, drop_temporary,
false, false);
thd->pop_internal_handler();
if (error)
@ -1863,39 +1928,38 @@ bool mysql_rm_table(THD *thd,TABLE_LIST *tables, my_bool if_exists,
DBUG_RETURN(FALSE);
}
/*
Execute the drop of a normal or temporary table
SYNOPSIS
mysql_rm_table_part2()
thd Thread handler
tables Tables to drop
if_exists If set, don't give an error if table doesn't exists.
In this case we give an warning of level 'NOTE'
drop_temporary Only drop temporary tables
drop_view Allow to delete VIEW .frm
dont_log_query Don't write query to log files. This will also not
generate warnings if the handler files doesn't exists
/**
Execute the drop of a normal or temporary table.
TODO:
When logging to the binary log, we should log
tmp_tables and transactional tables as separate statements if we
are in a transaction; This is needed to get these tables into the
cached binary log that is only written on COMMIT.
@param thd Thread handler
@param tables Tables to drop
@param if_exists If set, don't give an error if table doesn't exists.
In this case we give an warning of level 'NOTE'
@param drop_temporary Only drop temporary tables
@param drop_view Allow to delete VIEW .frm
@param dont_log_query Don't write query to log files. This will also not
generate warnings if the handler files doesn't exists
The current code only writes DROP statements that only uses temporary
tables to the cache binary log. This should be ok on most cases, but
not all.
@retval 0 ok
@retval 1 Error
@retval -1 Thread was killed
RETURN
0 ok
1 Error
-1 Thread was killed
@note This function assumes that metadata locks have already been taken.
It is also assumed that the tables have been removed from TDC.
@todo When logging to the binary log, we should log
tmp_tables and transactional tables as separate statements if we
are in a transaction; This is needed to get these tables into the
cached binary log that is only written on COMMIT.
The current code only writes DROP statements that only uses temporary
tables to the cache binary log. This should be ok on most cases, but
not all.
*/
int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
bool drop_temporary, bool drop_view,
bool dont_log_query)
int mysql_rm_table_no_locks(THD *thd, TABLE_LIST *tables, bool if_exists,
bool drop_temporary, bool drop_view,
bool dont_log_query)
{
TABLE_LIST *table;
char path[FN_REFLEN + 1], *alias= NULL;
@ -1909,7 +1973,7 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
bool non_tmp_table_deleted= 0;
String built_query;
String built_trans_tmp_query, built_non_trans_tmp_query;
DBUG_ENTER("mysql_rm_table_part2");
DBUG_ENTER("mysql_rm_table_no_locks");
/*
Prepares the drop statements that will be written into the binary
@ -1963,71 +2027,6 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
}
}
mysql_ha_rm_tables(thd, tables);
/* Disable drop of enabled log tables, must be done before name locking */
for (table= tables; table; table= table->next_local)
{
if (check_if_log_table(table->db_length, table->db,
table->table_name_length, table->table_name, 1))
{
my_error(ER_BAD_LOG_STATEMENT, MYF(0), "DROP");
DBUG_RETURN(1);
}
}
if (!drop_temporary)
{
if (!thd->locked_tables_mode)
{
if (lock_table_names(thd, tables, NULL, thd->variables.lock_wait_timeout,
MYSQL_OPEN_SKIP_TEMPORARY))
DBUG_RETURN(1);
for (table= tables; table; table= table->next_local)
{
tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table->db, table->table_name,
FALSE);
}
}
else
{
for (table= tables; table; table= table->next_local)
if (table->open_type != OT_BASE_ONLY &&
find_temporary_table(thd, table))
{
/*
A temporary table.
Don't try to find a corresponding MDL lock or assign it
to table->mdl_request.ticket. There can't be metadata
locks for temporary tables: they are local to the session.
Later in this function we release the MDL lock only if
table->mdl_requeset.ticket is not NULL. Thus here we
ensure that we won't release the metadata lock on the base
table locked with LOCK TABLES as a side effect of temporary
table drop.
*/
DBUG_ASSERT(table->mdl_request.ticket == NULL);
}
else
{
/*
Not a temporary table.
Since 'tables' list can't contain duplicates (this is ensured
by parser) it is safe to cache pointer to the TABLE instances
in its elements.
*/
table->table= find_table_for_mdl_upgrade(thd->open_tables, table->db,
table->table_name, FALSE);
if (!table->table)
DBUG_RETURN(1);
table->mdl_request.ticket= table->table->mdl_ticket;
}
}
}
for (table= tables; table; table= table->next_local)
{
bool is_trans;
@ -2039,6 +2038,16 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
table->db, table->table_name, (long) table->table,
table->table ? (long) table->table->s : (long) -1));
/*
If we are in locked tables mode and are dropping a temporary table,
the ticket should be NULL to ensure that we don't release a lock
on a base table later.
*/
DBUG_ASSERT(!(thd->locked_tables_mode &&
table->open_type != OT_BASE_ONLY &&
find_temporary_table(thd, table) &&
table->mdl_request.ticket != NULL));
/*
drop_temporary_table may return one of the following error codes:
. 0 - a temporary table was successfully dropped.
@ -2114,6 +2123,10 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
table->table= 0;
}
/* Check that we have an exclusive lock on the table to be dropped. */
DBUG_ASSERT(thd->mdl_context.is_lock_owner(MDL_key::TABLE, table->db,
table->table_name,
MDL_EXCLUSIVE));
if (thd->killed)
{
error= -1;
@ -2156,8 +2169,8 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
built_query.append("`,");
}
}
DEBUG_SYNC(thd, "rm_table_part2_before_delete_table");
DBUG_EXECUTE_IF("sleep_before_part2_delete_table",
DEBUG_SYNC(thd, "rm_table_no_locks_before_delete_table");
DBUG_EXECUTE_IF("sleep_before_no_locks_delete_table",
my_sleep(100000););
error= 0;
if (drop_temporary ||
@ -2244,7 +2257,7 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
ER(ER_BAD_TABLE_ERROR), MYF(0),
table->table_name););
}
DEBUG_SYNC(thd, "rm_table_part2_before_binlog");
DEBUG_SYNC(thd, "rm_table_no_locks_before_binlog");
thd->thread_specific_used|= (trans_tmp_table_deleted ||
non_trans_tmp_table_deleted);
error= 0;