Commit 05001e75 authored by unknown's avatar unknown
Browse files

Fix cases where SLEEP() calls would get optimized away or cached. (Bug #12689) 


mysql-test/r/func_misc.result:
  Add new results
mysql-test/t/func_misc.test:
  Add new regression test.
sql/item_create.cc:
  When SLEEP() is used, mark the statement as uncacheable.
sql/item_func.h:
  Flag SLEEP() as not constant, and set RAND_TABLE_BIT so that it is
  always evaluated.
parent 0f556e8f

mysql-test/r/func_misc.result

+24 −0
Original line number Diff line number Diff line
@@ -70,3 +70,27 @@ select timediff(b, a) >= '00:00:03' from t1; 
timediff(b, a) >= '00:00:03'

1

drop table t1;

set global query_cache_size=1355776;

create table t1 (a int);

insert into t1 values (1),(1),(1);

create table t2 (a datetime default null, b datetime default null);

insert into t2 set a = now();

select a from t1 where sleep(1);

a

update t2 set b = now() where b is null;

insert into t2 set a = now();

select a from t1 where sleep(a);

a

update t2 set b = now() where b is null;

insert into t2 set a = now();

select a from t1 where sleep(1);

a

update t2 set b = now() where b is null;

select timediff(b, a) >= '00:00:03' from t2;

timediff(b, a) >= '00:00:03'

1

1

1

drop table t2;

drop table t1;

set global query_cache_size=default;

mysql-test/t/func_misc.test

+23 −0
Original line number Diff line number Diff line
@@ -55,3 +55,26 @@ select sleep(3); 
update t1 set b = now();

select timediff(b, a) >= '00:00:03' from t1;

drop table t1;



#

# Bug #12689: SLEEP() gets incorrectly cached/optimized-away

#

set global query_cache_size=1355776;

create table t1 (a int);

insert into t1 values (1),(1),(1);

create table t2 (a datetime default null, b datetime default null);

insert into t2 set a = now();

select a from t1 where sleep(1);

update t2 set b = now() where b is null;

insert into t2 set a = now();

select a from t1 where sleep(a);

update t2 set b = now() where b is null;

insert into t2 set a = now();

select a from t1 where sleep(1);

update t2 set b = now() where b is null;

select timediff(b, a) >= '00:00:03' from t2;

drop table t2;

drop table t1;

set global query_cache_size=default;



# End of 5.0 tests

sql/item_create.cc

+1 −0
Original line number Diff line number Diff line
@@ -356,6 +356,7 @@ Item *create_func_sha(Item* a) 


Item *create_func_sleep(Item* a)

{

  current_thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);

  return new Item_func_sleep(a);

}

sql/item_func.h

+6 −0
Original line number Diff line number Diff line
@@ -893,7 +893,13 @@ class Item_func_sleep :public Item_int_func 
{

public:

  Item_func_sleep(Item *a) :Item_int_func(a) {}

  bool const_item() const { return 0; }

  const char *func_name() const { return "sleep"; }

  void update_used_tables()

  {

    Item_int_func::update_used_tables();

    used_tables_cache|= RAND_TABLE_BIT;

  }

  longlong val_int();

};