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- don't call JOIN::join_free(1) twice for every join in JOIN::cleanup().

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The reason it happened was that both, JOIN::cleanup() and JOIN::join_free(),
went over all nested joins and called cleanup/join_free for them.
For that:
- split recursive and non-recursive parts of JOIN::cleanup() and
JOIN::join_free()
- rename JOIN::cleanup to JOIN::destroy, as it actually destroys its
  argument
- move the recursive part of JOIN::cleanup to st_select_lex::cleanup
- move the non-recursive part of JOIN::join_free to the introduced
  method JOIN::cleanup().
This commit is contained in:
konstantin@mysql.com 2005-06-24 22:48:12 +04:00
parent c9de0b15f2
commit 56a37f8e07
4 changed files with 115 additions and 85 deletions
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5
sql/sql_lex.h
View File

@ -642,6 +642,11 @@ public:
static void print_order(String *str, ORDER *order);
void print_limit(THD *thd, String *str);
void fix_prepare_information(THD *thd, Item **conds);
/*
Destroy the used execution plan (JOIN) of this subtree (this
SELECT_LEX and all nested SELECT_LEXes and SELECT_LEX_UNITs).
*/
bool cleanup();
};
typedef class st_select_lex SELECT_LEX;

135
sql/sql_select.cc
View File

@ -87,10 +87,9 @@ static void update_depend_map(JOIN *join, ORDER *order);
static ORDER *remove_const(JOIN *join,ORDER *first_order,COND *cond,
bool change_list, bool *simple_order);
static int return_zero_rows(JOIN *join, select_result *res,TABLE_LIST *tables,
List<Item> &fields, bool send_row,
uint select_options, const char *info,
Item *having, Procedure *proc,
SELECT_LEX_UNIT *unit);
List<Item> &fields, bool send_row,
uint select_options, const char *info,
Item *having);
static COND *build_equal_items(THD *thd, COND *cond,
COND_EQUAL *inherited,
List<TABLE_LIST> *join_list,
@ -1227,8 +1226,7 @@ JOIN::exec()
send_row_on_empty_set(),
select_options,
zero_result_cause,
having, procedure,
unit);
having);
DBUG_VOID_RETURN;
}
@ -1437,7 +1435,7 @@ JOIN::exec()
DBUG_VOID_RETURN;
}
end_read_record(&curr_join->join_tab->read_record);
curr_join->const_tables= curr_join->tables; // Mark free for join_free()
curr_join->const_tables= curr_join->tables; // Mark free for cleanup()
curr_join->join_tab[0].table= 0; // Table is freed
// No sum funcs anymore
@ -1667,9 +1665,9 @@ JOIN::exec()
*/
int
JOIN::cleanup()
JOIN::destroy()
{
DBUG_ENTER("JOIN::cleanup");
DBUG_ENTER("JOIN::destroy");
select_lex->join= 0;
if (tmp_join)
@ -1684,12 +1682,11 @@ JOIN::cleanup()
}
tmp_join->tmp_join= 0;
tmp_table_param.copy_field=0;
DBUG_RETURN(tmp_join->cleanup());
DBUG_RETURN(tmp_join->destroy());
}
cond_equal= 0;
lock=0; // It's faster to unlock later
join_free(1);
cleanup(1);
if (exec_tmp_table1)
free_tmp_table(thd, exec_tmp_table1);
if (exec_tmp_table2)
@ -1697,12 +1694,6 @@ JOIN::cleanup()
delete select;
delete_dynamic(&keyuse);
delete procedure;
for (SELECT_LEX_UNIT *lex_unit= select_lex->first_inner_unit();
lex_unit != 0;
lex_unit= lex_unit->next_unit())
{
error|= lex_unit->cleanup();
}
DBUG_RETURN(error);
}
@ -1885,17 +1876,14 @@ Cursor::close()
THD *thd= join->thd;
DBUG_ENTER("Cursor::close");
join->join_free(0);
/*
In case of UNIONs JOIN is freed inside of unit->cleanup(),
otherwise in select_lex->cleanup().
*/
if (unit)
{
/* In case of UNIONs JOIN is freed inside unit->cleanup() */
unit->cleanup();
}
(void) unit->cleanup();
else
{
join->cleanup();
delete join;
}
(void) join->select_lex->cleanup();
{
/* XXX: Another hack: closing tables used in the cursor */
DBUG_ASSERT(lock || open_tables || derived_tables);
@ -2071,8 +2059,7 @@ err:
if (free_join)
{
thd->proc_info="end";
err= join->cleanup();
delete join;
err= select_lex->cleanup();
DBUG_RETURN(err || thd->net.report_error);
}
DBUG_RETURN(join->error);
@ -5905,29 +5892,75 @@ void JOIN_TAB::cleanup()
}
void JOIN::join_free(bool full)
{
SELECT_LEX_UNIT *unit;
SELECT_LEX *sl;
DBUG_ENTER("JOIN::join_free");
/*
Optimization: if not EXPLAIN and we are done with the JOIN,
free all tables.
*/
full= full || (!select_lex->uncacheable && !thd->lex->subqueries &&
!thd->lex->describe);
cleanup(full);
for (unit= select_lex->first_inner_unit(); unit; unit= unit->next_unit())
for (sl= unit->first_select_in_union(); sl; sl= sl->next_select())
{
JOIN *join= sl->join;
if (join)
{
/* Check that we don't occasionally clean up an uncacheable JOIN */
#if 0
DBUG_ASSERT(! (!select_lex->uncacheable && sl->uncacheable));
#endif
join->join_free(full);
}
}
/*
We are not using tables anymore
Unlock all tables. We may be in an INSERT .... SELECT statement.
*/
if (full && lock && thd->lock && !(select_options & SELECT_NO_UNLOCK) &&
!select_lex->subquery_in_having &&
(select_lex == (thd->lex->unit.fake_select_lex ?
thd->lex->unit.fake_select_lex : &thd->lex->select_lex)))
{
/*
TODO: unlock tables even if the join isn't top level select in the
tree.
*/
mysql_unlock_read_tables(thd, lock); // Don't free join->lock
lock= 0;
}
DBUG_VOID_RETURN;
}
/*
Free resources of given join
SYNOPSIS
JOIN::join_free()
JOIN::cleanup()
fill - true if we should free all resources, call with full==1 should be
last, before it this function can be called with full==0
NOTE: with subquery this function definitely will be called several times,
but even for simple query it can be called several times.
*/
void
JOIN::join_free(bool full)
{
JOIN_TAB *tab,*end;
DBUG_ENTER("JOIN::join_free");
full= full || (!select_lex->uncacheable &&
!thd->lex->subqueries &&
!thd->lex->describe); // do not cleanup too early on EXPLAIN
void JOIN::cleanup(bool full)
{
DBUG_ENTER("JOIN::cleanup");
if (table)
{
JOIN_TAB *tab,*end;
/*
Only a sorted table may be cached. This sorted table is always the
first non const table in join->table
@ -5938,16 +5971,6 @@ JOIN::join_free(bool full)
filesort_free_buffers(table[const_tables]);
}
for (SELECT_LEX_UNIT *unit= select_lex->first_inner_unit(); unit;
unit= unit->next_unit())
{
JOIN *join;
for (SELECT_LEX *sl= unit->first_select_in_union(); sl;
sl= sl->next_select())
if ((join= sl->join))
join->join_free(full);
}
if (full)
{
for (tab= join_tab, end= tab+tables; tab != end; tab++)
@ -5964,23 +5987,10 @@ JOIN::join_free(bool full)
}
}
}
/*
We are not using tables anymore
Unlock all tables. We may be in an INSERT .... SELECT statement.
*/
if (full && lock && thd->lock && !(select_options & SELECT_NO_UNLOCK) &&
!select_lex->subquery_in_having)
{
// TODO: unlock tables even if the join isn't top level select in the tree
if (select_lex == (thd->lex->unit.fake_select_lex ?
thd->lex->unit.fake_select_lex : &thd->lex->select_lex))
{
mysql_unlock_read_tables(thd, lock); // Don't free join->lock
lock=0;
}
}
if (full)
{
group_fields.delete_elements();
@ -6217,8 +6227,7 @@ remove_const(JOIN *join,ORDER *first_order, COND *cond,
static int
return_zero_rows(JOIN *join, select_result *result,TABLE_LIST *tables,
List<Item> &fields, bool send_row, uint select_options,
const char *info, Item *having, Procedure *procedure,
SELECT_LEX_UNIT *unit)
const char *info, Item *having)
{
DBUG_ENTER("return_zero_rows");

10
sql/sql_select.h
View File

@ -325,7 +325,7 @@ class JOIN :public Sql_alloc
int optimize();
int reinit();
void exec();
int cleanup();
int destroy();
void restore_tmp();
bool alloc_func_list();
bool make_sum_func_list(List<Item> &all_fields, List<Item> &send_fields,
@ -349,7 +349,15 @@ class JOIN :public Sql_alloc
int rollup_send_data(uint idx);
int rollup_write_data(uint idx, TABLE *table);
bool test_in_subselect(Item **where);
/*
Release memory and, if possible, the open tables held by this execution
plan (and nested plans). It's used to release some tables before
the end of execution in order to increase concurrency and reduce
memory consumption.
*/
void join_free(bool full);
/* Cleanup this JOIN, possibly for reuse */
void cleanup(bool full);
void clear();
bool save_join_tab();
bool send_row_on_empty_set()

50
sql/sql_union.cc
View File

@ -553,7 +553,6 @@ bool st_select_lex_unit::exec()
bool st_select_lex_unit::cleanup()
{
int error= 0;
JOIN *join;
DBUG_ENTER("st_select_lex_unit::cleanup");
if (cleaned)
@ -572,29 +571,17 @@ bool st_select_lex_unit::cleanup()
}
for (SELECT_LEX *sl= first_select_in_union(); sl; sl= sl->next_select())
error|= sl->cleanup();
if (fake_select_lex)
{
if ((join= sl->join))
JOIN *join;
if ((join= fake_select_lex->join))
{
error|= sl->join->cleanup();
delete join;
join->tables_list= 0;
join->tables= 0;
}
else
{
// it can be DO/SET with subqueries
for (SELECT_LEX_UNIT *lex_unit= sl->first_inner_unit();
lex_unit != 0;
lex_unit= lex_unit->next_unit())
{
error|= lex_unit->cleanup();
}
}
}
if (fake_select_lex && (join= fake_select_lex->join))
{
join->tables_list= 0;
join->tables= 0;
error|= join->cleanup();
delete join;
error|= fake_select_lex->cleanup();
}
DBUG_RETURN(error);
@ -650,3 +637,24 @@ bool st_select_lex_unit::change_result(select_subselect *result,
res= fake_select_lex->join->change_result(result);
return (res);
}
bool st_select_lex::cleanup()
{
bool error= FALSE;
DBUG_ENTER("st_select_lex::cleanup()");
if (join)
{
error|= join->destroy();
delete join;
join= 0;
}
for (SELECT_LEX_UNIT *lex_unit= first_inner_unit(); lex_unit ;
lex_unit= lex_unit->next_unit())
{
error|= lex_unit->cleanup();
}
DBUG_RETURN(error);
}