bk commit into 5.0 tree (gkodinov:1.2261) BUG#21798

[kgeorge]

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ChangeSet@stripped, 2006-09-14 11:20:41+03:00, gkodinov@stripped +8 -0
  Bug#21798: memory leak during query execution with subquery in column
              list using a function
  When executing dependent subqueries they are re-inited and re-exec() for 
  each row of the outer context.
  Care must be taken not to allocate anything into the thread's memory pool
  while reiniting that.
  All such items mush be cached and reused because the thread's memory pool
  is freed at the end of the whole query.
  Most of the stuff that is allocated in JOIN::exec is taken care of (e.g.
  JOIN::exec_tmp_table2), but there are some that remain.
  Note that they must be cached and reused even for queries that are not 
  otherwise cacheable. 
  So we provide a structure (initialized and maintained as an unit) to 
  store references to the items that need to be cached.

  mysql-test/r/subselect.result@stripped, 2006-09-14 11:20:24+03:00, gkodinov@stripped +26
-0
    Bug#21798: memory leak during query execution with subquery in column
                list using a function
     - test case

  mysql-test/t/subselect.test@stripped, 2006-09-14 11:20:26+03:00, gkodinov@stripped +26
-0
    Bug#21798: memory leak during query execution with subquery in column
                list using a function
     - test case

  sql/mysql_priv.h@stripped, 2006-09-14 11:20:27+03:00, gkodinov@stripped +2 -1
    Bug#21798: memory leak during query execution with subquery in column
                list using a function
     - need to cache the entities allocated in the threads memory pool by
       JOIN::exec ().

  sql/sql_delete.cc@stripped, 2006-09-14 11:20:28+03:00, gkodinov@stripped +1 -1
    Bug#21798: memory leak during query execution with subquery in column
                list using a function
     - need to cache the entities allocated in the threads memory pool by
       JOIN::exec ().

  sql/sql_select.cc@stripped, 2006-09-14 11:20:30+03:00, gkodinov@stripped +36 -9
    Bug#21798: memory leak during query execution with subquery in column
                list using a function
     - need to cache the entities allocated in the threads memory pool by
       JOIN::exec ().
       It is better to collect all such items in unified storage for cacheable
       items inside JOIN.

  sql/sql_select.h@stripped, 2006-09-14 11:20:31+03:00, gkodinov@stripped +13 -0
    Bug#21798: memory leak during query execution with subquery in column
                list using a function
     - need to cache the entities allocated in the threads memory pool by
       JOIN::exec ().
       It is better to collect all such items in unified storage for cacheable
       items inside JOIN.

  sql/sql_table.cc@stripped, 2006-09-14 11:20:32+03:00, gkodinov@stripped +1 -1
    Bug#21798: memory leak during query execution with subquery in column
                list using a function
     - need to cache the entities allocated in the threads memory pool by
       JOIN::exec ().

  sql/sql_update.cc@stripped, 2006-09-14 11:20:33+03:00, gkodinov@stripped +1 -1
    Bug#21798: memory leak during query execution with subquery in column
                list using a function
     - need to cache the entities allocated in the threads memory pool by
       JOIN::exec ().

# 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:	gkodinov
# Host:	macbook.gmz
# Root:	/Users/kgeorge/mysql/work/B21798-5.0-opt

--- 1.407/sql/mysql_priv.h	2006-09-14 11:21:02 +03:00
+++ 1.408/sql/mysql_priv.h	2006-09-14 11:21:02 +03:00
@@ -708,7 +708,8 @@ bool mysql_xa_recover(THD *thd);
 
 bool check_simple_select();
 
-SORT_FIELD * make_unireg_sortorder(ORDER *order, uint *length);
+SORT_FIELD *make_unireg_sortorder(ORDER *order, uint *length,
+                                  SORT_FIELD *cache, uint cached_len);
 int setup_order(THD *thd, Item **ref_pointer_array, TABLE_LIST *tables,
 		List<Item> &fields, List <Item> &all_fields, ORDER *order);
 int setup_group(THD *thd, Item **ref_pointer_array, TABLE_LIST *tables,

--- 1.178/sql/sql_delete.cc	2006-09-14 11:21:02 +03:00
+++ 1.179/sql/sql_delete.cc	2006-09-14 11:21:02 +03:00
@@ -167,7 +167,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *
                                                    MYF(MY_FAE | MY_ZEROFILL));
     
       if (!(sortorder= make_unireg_sortorder((ORDER*) order->first,
-                                             &length)) ||
+                                             &length, NULL, 0)) ||
 	  (table->sort.found_records = filesort(thd, table, sortorder, length,
                                                 select, HA_POS_ERROR,
                                                 &examined_rows))

--- 1.450/sql/sql_select.cc	2006-09-14 11:21:03 +03:00
+++ 1.451/sql/sql_select.cc	2006-09-14 11:21:03 +03:00
@@ -76,7 +76,9 @@ static store_key *get_store_key(THD *thd
 				KEYUSE *keyuse, table_map used_tables,
 				KEY_PART_INFO *key_part, char *key_buff,
 				uint maybe_null);
-static bool make_simple_join(JOIN *join,TABLE *tmp_table);
+static bool make_simple_join(JOIN *join,TABLE *tmp_table,
+                 TABLE ***simplejoin_tableptr_cache,
+                 JOIN_TAB **simplejoin_tab_cache);
 static void make_outerjoin_info(JOIN *join);
 static bool make_join_select(JOIN *join,SQL_SELECT *select,COND *item);
 static void make_join_readinfo(JOIN *join,uint options);
@@ -1273,7 +1275,10 @@ JOIN::reinit()
     memcpy(join_tab, join_tab_save, sizeof(JOIN_TAB) * tables);
 
   if (tmp_join)
+  {
+    memcpy(&subq_cache, &tmp_join->subq_cache, sizeof (subq_cache));
     restore_tmp();
+  }
 
   /* Reset of sum functions */
   if (sum_funcs)
@@ -1435,6 +1440,7 @@ JOIN::exec()
         (curr_join may have been modified during last exection and we need
         to reset it)
       */
+      tmp_join->subq_cache= curr_join->subq_cache;
       curr_join= tmp_join;
     }
     curr_tmp_table= exec_tmp_table1;
@@ -1523,7 +1529,9 @@ JOIN::exec()
       
       /* Free first data from old join */
       curr_join->join_free();
-      if (make_simple_join(curr_join, curr_tmp_table))
+      if (make_simple_join(curr_join, curr_tmp_table,
+                           &curr_join->subq_cache.simplejoin_table_ptr_cache1,
+                           &curr_join->subq_cache.simplejoin_tab_cache1))
 	DBUG_VOID_RETURN;
       calc_group_buffer(curr_join, group_list);
       count_field_types(&curr_join->tmp_table_param,
@@ -1642,7 +1650,9 @@ JOIN::exec()
       curr_join->select_distinct=0;
     }
     curr_tmp_table->reginfo.lock_type= TL_UNLOCK;
-    if (make_simple_join(curr_join, curr_tmp_table))
+    if (make_simple_join(curr_join, curr_tmp_table,
+                         &curr_join->subq_cache.simplejoin_table_ptr_cache2,
+                         &curr_join->subq_cache.simplejoin_tab_cache2))
       DBUG_VOID_RETURN;
     calc_group_buffer(curr_join, curr_join->group_list);
     count_field_types(&curr_join->tmp_table_param, *curr_all_fields, 0);
@@ -4943,15 +4953,25 @@ store_val_in_field(Field *field, Item *i
 
 
 static bool
-make_simple_join(JOIN *join,TABLE *tmp_table)
+make_simple_join(JOIN *join,TABLE *tmp_table,
+                 TABLE ***simplejoin_tableptr_cache,
+                 JOIN_TAB **simplejoin_tab_cache)
 {
   TABLE **tableptr;
   JOIN_TAB *join_tab;
   DBUG_ENTER("make_simple_join");
 
-  if (!(tableptr=(TABLE**) join->thd->alloc(sizeof(TABLE*))) ||
-      !(join_tab=(JOIN_TAB*) join->thd->alloc(sizeof(JOIN_TAB))))
+  if (*simplejoin_tableptr_cache)
+    tableptr= *simplejoin_tableptr_cache;
+  else if (!(*simplejoin_tableptr_cache= 
+             tableptr=(TABLE**) join->thd->alloc(sizeof(TABLE*))))
     DBUG_RETURN(TRUE);
+  if (*simplejoin_tab_cache)
+    join_tab= *simplejoin_tab_cache;
+  else if (!(*simplejoin_tab_cache= 
+             join_tab=(JOIN_TAB*) join->thd->alloc(sizeof(JOIN_TAB))))
+    DBUG_RETURN(TRUE);
+
   join->join_tab=join_tab;
   join->table=tableptr; tableptr[0]=tmp_table;
   join->tables=1;
@@ -11987,8 +12007,12 @@ create_sort_index(THD *thd, JOIN *join, 
 
   if (test_if_skip_sort_order(tab,order,select_limit,0))
     DBUG_RETURN(0);
-  if (!(sortorder=make_unireg_sortorder(order,&length)))
+  if (!(join->subq_cache.sortorder_cache= 
+        sortorder= make_unireg_sortorder(order,&length,
+                                         join->subq_cache.sortorder_cache,
+                                         join->subq_cache.sortorder_cache_len)))
     goto err;				/* purecov: inspected */
+  join->subq_cache.sortorder_cache_len= length;
   /* It's not fatal if the following alloc fails */
   table->sort.io_cache=(IO_CACHE*) my_malloc(sizeof(IO_CACHE),
                                              MYF(MY_WME | MY_ZEROFILL));
@@ -12381,7 +12405,8 @@ err:
 }
 
 
-SORT_FIELD *make_unireg_sortorder(ORDER *order, uint *length)
+SORT_FIELD *make_unireg_sortorder(ORDER *order, uint *length,
+                                  SORT_FIELD *cache, uint cached_len)
 {
   uint count;
   SORT_FIELD *sort,*pos;
@@ -12390,7 +12415,9 @@ SORT_FIELD *make_unireg_sortorder(ORDER 
   count=0;
   for (ORDER *tmp = order; tmp; tmp=tmp->next)
     count++;
-  pos=sort=(SORT_FIELD*) sql_alloc(sizeof(SORT_FIELD)*(count+1));
+  if (!cache || cached_len != count)
+    cache= (SORT_FIELD*) sql_alloc(sizeof(SORT_FIELD)*(count+1));
+  pos= sort= cache;
   if (!pos)
     return 0;
 

--- 1.109/sql/sql_select.h	2006-09-14 11:21:03 +03:00
+++ 1.110/sql/sql_select.h	2006-09-14 11:21:03 +03:00
@@ -282,6 +282,18 @@ public:
   bool union_part; // this subselect is part of union 
   bool optimized; // flag to avoid double optimization in EXPLAIN
 
+  /* 
+    cache for the the transformed JOIN elements used by make_simple_join 
+    We need to preserve these elements even if the join itself is not 
+    cacheable
+  */
+  struct {
+    TABLE **simplejoin_table_ptr_cache1, **simplejoin_table_ptr_cache2;
+    JOIN_TAB *simplejoin_tab_cache1, *simplejoin_tab_cache2; 
+    SORT_FIELD *sortorder_cache;
+    uint sortorder_cache_len;
+  } subq_cache;
+
   JOIN(THD *thd_arg, List<Item> &fields_arg, ulonglong select_options_arg,
        select_result *result_arg)
     :fields_list(fields_arg)
@@ -307,6 +319,7 @@ public:
     examined_rows= 0;
     exec_tmp_table1= 0;
     exec_tmp_table2= 0;
+    bzero (&subq_cache, sizeof (subq_cache));
     thd= thd_arg;
     sum_funcs= sum_funcs2= 0;
     procedure= 0;

--- 1.320/sql/sql_table.cc	2006-09-14 11:21:03 +03:00
+++ 1.321/sql/sql_table.cc	2006-09-14 11:21:03 +03:00
@@ -4044,7 +4044,7 @@ copy_data_between_tables(TABLE *from,TAB
     if (thd->lex->select_lex.setup_ref_array(thd, order_num) ||
 	setup_order(thd, thd->lex->select_lex.ref_pointer_array,
 		    &tables, fields, all_fields, order) ||
-	!(sortorder=make_unireg_sortorder(order, &length)) ||
+	!(sortorder=make_unireg_sortorder(order, &length, NULL, 0)) ||
 	(from->sort.found_records = filesort(thd, from, sortorder, length,
 					     (SQL_SELECT *) 0, HA_POS_ERROR,
 					     &examined_rows)) ==

--- 1.196/sql/sql_update.cc	2006-09-14 11:21:03 +03:00
+++ 1.197/sql/sql_update.cc	2006-09-14 11:21:03 +03:00
@@ -311,7 +311,7 @@ int mysql_update(THD *thd,
 
       table->sort.io_cache = (IO_CACHE *) my_malloc(sizeof(IO_CACHE),
 						    MYF(MY_FAE | MY_ZEROFILL));
-      if (!(sortorder=make_unireg_sortorder(order, &length)) ||
+      if (!(sortorder=make_unireg_sortorder(order, &length, NULL, 0)) ||
           (table->sort.found_records = filesort(thd, table, sortorder, length,
 						select, limit,
 						&examined_rows))

--- 1.156/mysql-test/r/subselect.result	2006-09-14 11:21:03 +03:00
+++ 1.157/mysql-test/r/subselect.result	2006-09-14 11:21:03 +03:00
@@ -3393,3 +3393,29 @@ id	select_type	table	type	possible_keys	
 4	UNION	t12	system	NULL	NULL	NULL	NULL	0	const row not found
 NULL	UNION RESULT	<union2,4>	ALL	NULL	NULL	NULL	NULL	NULL	
 DROP TABLE t1;
+CREATE TABLE t1 (a VARCHAR(250), b INT auto_increment, PRIMARY KEY (b));
+insert into t1 (a) values (FLOOR(rand() * 100));
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+SELECT a, 
+(SELECT REPEAT(' ',250) FROM t1 i1 
+WHERE i1.b=t1.a ORDER BY RAND() LIMIT 1) AS a 
+FROM t1 ORDER BY a LIMIT 5;
+a	a
+0	NULL
+0	NULL
+0	NULL
+0	NULL
+0	NULL
+DROP TABLE t1;

--- 1.126/mysql-test/t/subselect.test	2006-09-14 11:21:03 +03:00
+++ 1.127/mysql-test/t/subselect.test	2006-09-14 11:21:03 +03:00
@@ -2306,3 +2306,29 @@ explain select * from t1 where not exist
   ((select t11.i from t1 t11) union (select t12.i from t1 t12));
 
 DROP TABLE t1;
+
+#
+# Bug#21798: memory leak during query execution with subquery in column 
+#             list using a function
+#
+CREATE TABLE t1 (a VARCHAR(250), b INT auto_increment, PRIMARY KEY (b));
+insert into t1 (a) values (FLOOR(rand() * 100));
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+insert into t1 (a) select FLOOR(rand() * 100) from t1;
+
+SELECT a, 
+       (SELECT REPEAT(' ',250) FROM t1 i1 
+        WHERE i1.b=t1.a ORDER BY RAND() LIMIT 1) AS a 
+FROM t1 ORDER BY a LIMIT 5;
+DROP TABLE t1;