Commit 49bd559e authored by unknown's avatar unknown

Fix for Bug#5034 "prepared "select 1 into @arg15", second

execute crashes server": we were deleting lex->result
after each execute, but prepared statements assumed that
it's left intact.
The fix adds cleanup() method to select_result hierarchy,
so that result objects can be reused.
Plus we now need to delete result objects more wisely.


mysql-test/r/ps.result:
  Test results fixed: test case for bug#5034
mysql-test/t/ps.test:
  A test case for bug#5034, few followups
sql/sql_class.cc:
  - fix warning in THD::THD
  - implementation of cleanup() for select_result hierarchy
  - select_export::send_eof was identical to 
    select_dump::send_eof: moved to the base class select_to_file.
  - Statement::end_statement() to end lex, free items, and
    delete possible select_result
sql/sql_class.h:
  - select_result::cleanup() declaration
  -
sql/sql_insert.cc:
  - implementation of select_insert::cleanup(): currently
    we always create a new instance of select_insert/
    select_create on each execute.
sql/sql_lex.cc:
  - with more complicated logic of freeing lex->result it's 
    easier to have it non-zero only if it points to a valid
    result.
sql/sql_lex.h:
  Now st_lex::st_lex is not empty.
sql/sql_parse.cc:
  mysql_execute_command():
  - delete select_result *result only if it was created in
    this function.
  - use end_statement() to cleanup lex and thd in the end of
    each statement.
  - no need to save THD::lock if this is explain. This save
    apparently left from times when derived tables were 
    materialized here, not in open_and_lock_tables.
sql/sql_prepare.cc:
  - call result->cleanup() in reset_stmt_for_execute
  - now Statement is responsible for freeing its lex->result.
sql/sql_select.cc:
  handle_select():
  - don't delete result, it might be needed
    for next executions
  - result is never null
parent 83e3d3f9
......@@ -226,3 +226,18 @@ a b
execute stmt1;
a b
deallocate prepare stmt1;
drop table t1;
prepare stmt1 from "select 1 into @var";
execute stmt1;
execute stmt1;
prepare stmt1 from "create table t1 select 1 as i";
execute stmt1;
drop table t1;
execute stmt1;
prepare stmt1 from "insert into t1 select i from t1";
execute stmt1;
execute stmt1;
prepare stmt1 from "select * from t1 into outfile 'f1.txt'";
execute stmt1;
deallocate prepare stmt1;
drop table t1;
......@@ -209,7 +209,7 @@ drop table t1;
#
# Bug#4912 "mysqld crashs in case a statement is executed a second time":
# negation elimination should and prepared statemens
# negation elimination should work once and not break prepared statements
#
create table t1(a varchar(2), b varchar(3));
......@@ -217,4 +217,26 @@ prepare stmt1 from "select a, b from t1 where (not (a='aa' and b < 'zzz'))";
execute stmt1;
execute stmt1;
deallocate prepare stmt1;
drop table t1;
#
# Bug#5034 "prepared "select 1 into @arg15", second execute crashes
# server".
# Check that descendands of select_result can be reused in prepared
# statements or are correctly created and deleted on each execute
#
prepare stmt1 from "select 1 into @var";
execute stmt1;
execute stmt1;
prepare stmt1 from "create table t1 select 1 as i";
execute stmt1;
drop table t1;
execute stmt1;
prepare stmt1 from "insert into t1 select i from t1";
execute stmt1;
execute stmt1;
prepare stmt1 from "select * from t1 into outfile 'f1.txt'";
execute stmt1;
deallocate prepare stmt1;
drop table t1;
......@@ -155,10 +155,10 @@ bool foreign_key_prefix(Key *a, Key *b)
** Thread specific functions
****************************************************************************/
THD::THD():user_time(0), current_arena(this), is_fatal_error(0),
last_insert_id_used(0),
THD::THD():user_time(0), current_arena(this), global_read_lock(0),
is_fatal_error(0), last_insert_id_used(0),
insert_id_used(0), rand_used(0), time_zone_used(0),
in_lock_tables(0), global_read_lock(0), bootstrap(0)
in_lock_tables(0), bootstrap(0)
{
host= user= priv_user= db= ip=0;
host_or_ip= "connecting host";
......@@ -703,6 +703,12 @@ void select_result::send_error(uint errcode,const char *err)
::send_error(thd, errcode, err);
}
void select_result::cleanup()
{
/* do nothing */
}
static String default_line_term("\n",default_charset_info);
static String default_escaped("\\",default_charset_info);
static String default_field_term("\t",default_charset_info);
......@@ -808,6 +814,32 @@ void select_to_file::send_error(uint errcode,const char *err)
}
bool select_to_file::send_eof()
{
int error= test(end_io_cache(&cache));
if (my_close(file,MYF(MY_WME)))
error= 1;
if (!error)
::send_ok(thd,row_count);
file= -1;
return error;
}
void select_to_file::cleanup()
{
/* In case of error send_eof() may be not called: close the file here. */
if (file >= 0)
{
(void) end_io_cache(&cache);
(void) my_close(file,MYF(0));
file= -1;
}
path[0]= '\0';
row_count= 0;
}
select_to_file::~select_to_file()
{
if (file >= 0)
......@@ -1058,18 +1090,6 @@ bool select_export::send_data(List<Item> &items)
}
bool select_export::send_eof()
{
int error=test(end_io_cache(&cache));
if (my_close(file,MYF(MY_WME)))
error=1;
if (!error)
::send_ok(thd,row_count);
file= -1;
return error;
}
/***************************************************************************
** Dump of select to a binary file
***************************************************************************/
......@@ -1123,18 +1143,6 @@ bool select_dump::send_data(List<Item> &items)
}
bool select_dump::send_eof()
{
int error=test(end_io_cache(&cache));
if (my_close(file,MYF(MY_WME)))
error=1;
if (!error)
::send_ok(thd,row_count);
file= -1;
return error;
}
select_subselect::select_subselect(Item_subselect *item_arg)
{
item= item_arg;
......@@ -1301,6 +1309,13 @@ int select_dumpvar::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
}
void select_dumpvar::cleanup()
{
vars.empty();
row_count=0;
}
Item_arena::Item_arena(THD* thd)
:free_list(0),
state(INITIALIZED)
......@@ -1405,6 +1420,21 @@ void Statement::restore_backup_statement(Statement *stmt, Statement *backup)
}
void Statement::end_statement()
{
/* Cleanup SQL processing state to resuse this statement in next query. */
lex_end(lex);
delete lex->result;
lex->result= 0;
free_items(free_list);
free_list= 0;
/*
Don't free mem_root, as mem_root is freed in the end of dispatch_command
(once for any command).
*/
}
void Item_arena::set_n_backup_item_arena(Item_arena *set, Item_arena *backup)
{
backup->set_item_arena(this);
......
......@@ -547,6 +547,12 @@ class Statement: public Item_arena
void restore_backup_statement(Statement *stmt, Statement *backup);
/* return class type */
virtual Type type() const;
/*
Cleanup statement parse state (parse tree, lex) after execution of
a non-prepared SQL statement.
*/
void end_statement();
};
......@@ -1029,10 +1035,13 @@ class Disable_binlog {
~Disable_binlog();
};
/*
Used to hold information about file and file structure in exchainge
via non-DB file (...INTO OUTFILE..., ...LOAD DATA...)
XXX: We never call destructor for objects of this class.
*/
class sql_exchange :public Sql_alloc
{
public:
......@@ -1042,7 +1051,6 @@ class sql_exchange :public Sql_alloc
bool dumpfile;
ulong skip_lines;
sql_exchange(char *name,bool dumpfile_flag);
~sql_exchange() {}
};
#include "log_event.h"
......@@ -1073,6 +1081,11 @@ class select_result :public Sql_alloc {
virtual void send_error(uint errcode,const char *err);
virtual bool send_eof()=0;
virtual void abort() {}
/*
Cleanup instance of this class for next execution of a prepared
statement/stored procedure.
*/
virtual void cleanup();
};
......@@ -1099,6 +1112,8 @@ class select_to_file :public select_result {
~select_to_file();
bool send_fields(List<Item> &list, uint flag) { return 0; }
void send_error(uint errcode,const char *err);
bool send_eof();
void cleanup();
};
......@@ -1111,7 +1126,6 @@ class select_export :public select_to_file {
~select_export();
int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
bool send_data(List<Item> &items);
bool send_eof();
};
......@@ -1120,7 +1134,6 @@ class select_dump :public select_to_file {
select_dump(sql_exchange *ex) :select_to_file(ex) {}
int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
bool send_data(List<Item> &items);
bool send_eof();
};
......@@ -1145,6 +1158,8 @@ class select_insert :public select_result {
bool send_data(List<Item> &items);
void send_error(uint errcode,const char *err);
bool send_eof();
/* not implemented: select_insert is never re-used in prepared statements */
void cleanup();
};
......@@ -1445,4 +1460,5 @@ class select_dumpvar :public select_result {
bool send_fields(List<Item> &list, uint flag) {return 0;}
bool send_data(List<Item> &items);
bool send_eof();
void cleanup();
};
......@@ -1465,6 +1465,13 @@ select_insert::prepare(List<Item> &values, SELECT_LEX_UNIT *u)
DBUG_RETURN(0);
}
void select_insert::cleanup()
{
/* select_insert/select_create are never re-used in prepared statement */
DBUG_ASSERT(0);
}
select_insert::~select_insert()
{
if (table)
......
......@@ -1653,6 +1653,11 @@ void st_select_lex::print_limit(THD *thd, String *str)
}
st_lex::st_lex()
:result(0)
{}
/*
Unlink first table from global table list and first table from outer select
list (lex->select_lex)
......
......@@ -639,7 +639,7 @@ typedef struct st_lex
list of those tables after they are opened.
*/
TABLE_LIST *time_zone_tables_used;
st_lex() {}
st_lex();
inline void uncacheable(uint8 cause)
{
safe_to_cache_query= 0;
......
......@@ -1967,8 +1967,6 @@ mysql_execute_command(THD *thd)
else
thd->send_explain_fields(result);
res= mysql_explain_union(thd, &thd->lex->unit, result);
MYSQL_LOCK *save_lock= thd->lock;
thd->lock= (MYSQL_LOCK *)0;
if (lex->describe & DESCRIBE_EXTENDED)
{
char buff[1024];
......@@ -1980,20 +1978,19 @@ mysql_execute_command(THD *thd)
ER_YES, str.ptr());
}
result->send_eof();
thd->lock= save_lock;
delete result;
}
else
{
if (!result)
if (!result && !(result= new select_send()))
{
if (!(result=new select_send()))
{
res= -1;
break;
}
res= -1;
break;
}
query_cache_store_query(thd, tables);
res=handle_select(thd, lex, result);
res= handle_select(thd, lex, result);
if (result != lex->result)
delete result;
}
}
break;
......@@ -2708,23 +2705,24 @@ mysql_execute_command(THD *thd)
}
if (!(res=open_and_lock_tables(thd, tables)))
if (!(res= open_and_lock_tables(thd, tables)) &&
(result= new select_insert(tables->table, &lex->field_list,
lex->duplicates)))
{
if ((result=new select_insert(tables->table,&lex->field_list,
lex->duplicates)))
/* Skip first table, which is the table we are inserting in */
lex->select_lex.table_list.first= (byte*) first_local_table->next;
/*
insert/replace from SELECT give its SELECT_LEX for SELECT,
and item_list belong to SELECT
*/
lex->select_lex.resolve_mode= SELECT_LEX::SELECT_MODE;
res=handle_select(thd,lex,result);
/* revert changes for SP */
lex->select_lex.table_list.first= (byte*) first_local_table;
lex->select_lex.resolve_mode= SELECT_LEX::INSERT_MODE;
/* Skip first table, which is the table we are inserting in */
lex->select_lex.table_list.first= (byte*) first_local_table->next;
/*
insert/replace from SELECT give its SELECT_LEX for SELECT,
and item_list belong to SELECT
*/
lex->select_lex.resolve_mode= SELECT_LEX::SELECT_MODE;
res= handle_select(thd, lex, result);
/* revert changes for SP */
lex->select_lex.table_list.first= (byte*) first_local_table;
lex->select_lex.resolve_mode= SELECT_LEX::INSERT_MODE;
delete result;
if (thd->net.report_error)
res= -1;
res= -1;
}
else
res= -1;
......@@ -3904,8 +3902,8 @@ mysql_init_select(LEX *lex)
select_lex->select_limit= HA_POS_ERROR;
if (select_lex == &lex->select_lex)
{
DBUG_ASSERT(lex->result == 0);
lex->exchange= 0;
lex->result= 0;
lex->proc_list.first= 0;
}
}
......@@ -4047,9 +4045,7 @@ void mysql_parse(THD *thd, char *inBuf, uint length)
query_cache_abort(&thd->net);
}
thd->proc_info="freeing items";
free_items(thd->free_list); /* Free strings used by items */
thd->free_list= 0;
lex_end(lex);
thd->end_statement();
}
DBUG_VOID_RETURN;
}
......@@ -4074,10 +4070,7 @@ bool mysql_test_parse_for_slave(THD *thd, char *inBuf, uint length)
if (!yyparse((void*) thd) && ! thd->is_fatal_error &&
all_tables_not_ok(thd,(TABLE_LIST*) lex->select_lex.table_list.first))
error= 1; /* Ignore question */
free_items(thd->free_list); /* Free strings used by items */
thd->free_list= 0;
lex_end(lex);
thd->end_statement();
return error;
}
#endif
......
......@@ -1630,7 +1630,8 @@ int mysql_stmt_prepare(THD *thd, char *packet, uint packet_length,
static void reset_stmt_for_execute(Prepared_statement *stmt)
{
THD *thd= stmt->thd;
SELECT_LEX *sl= stmt->lex->all_selects_list;
LEX *lex= stmt->lex;
SELECT_LEX *sl= lex->all_selects_list;
for (; sl; sl= sl->next_select_in_list())
{
......@@ -1678,7 +1679,9 @@ static void reset_stmt_for_execute(Prepared_statement *stmt)
unit->reinit_exec_mechanism();
}
}
stmt->lex->current_select= &stmt->lex->select_lex;
lex->current_select= &lex->select_lex;
if (lex->result)
lex->result->cleanup();
}
......@@ -2053,6 +2056,7 @@ void Prepared_statement::setup_set_params()
Prepared_statement::~Prepared_statement()
{
free_items(free_list);
delete lex->result;
}
......
......@@ -199,16 +199,10 @@ int handle_select(THD *thd, LEX *lex, select_result *result)
res= 1;
if (res)
{
if (result)
{
result->send_error(0, NullS);
result->abort();
}
else
send_error(thd, 0, NullS);
result->send_error(0, NullS);
result->abort();
res= 1; // Error sent to client
}
delete result;
DBUG_RETURN(res);
}
......
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