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Merge bk-internal.mysql.com:/home/bk/mysql-4.1

Browse source 
into  mysql.com:/opt/local/work/mysql-4.1-16365


sql/mysql_priv.h:
  Auto merged
sql/sql_class.h:
  Auto merged
mysql-test/r/ps.result:
  Manual merge
mysql-test/t/ps.test:
  Manual merge
This commit is contained in:
unknown 2006-04-07 23:50:45 +04:00
commit f37d610147
9 changed files with 464 additions and 60 deletions
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108
mysql-test/r/ps.result
View file

@ -107,6 +107,9 @@ set @fvar= 123.4567;
prepare stmt1 from @fvar;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '123.4567' at line 1
drop table t1,t2;
deallocate prepare stmt3;
deallocate prepare stmt4;
deallocate prepare stmt5;
PREPARE stmt1 FROM "select _utf8 'A' collate utf8_bin = ?";
set @var='A';
EXECUTE stmt1 USING @var;
@ -252,6 +255,7 @@ set names latin1;
execute `ü`;
1234
1234
deallocate prepare `ü`;
set names default;
create table t1 (a varchar(10)) charset=utf8;
insert into t1 (a) values ('yahoo');
@ -767,3 +771,107 @@ execute stmt using @a,@b;
col1 col2
deallocate prepare stmt;
drop table t1;
set @old_max_prepared_stmt_count= @@max_prepared_stmt_count;
show variables like 'max_prepared_stmt_count';
Variable_name Value
max_prepared_stmt_count 16382
show variables like 'prepared_stmt_count';
Variable_name Value
prepared_stmt_count 0
select @@max_prepared_stmt_count, @@prepared_stmt_count;
@@max_prepared_stmt_count @@prepared_stmt_count
16382 0
set global max_prepared_stmt_count=-1;
select @@max_prepared_stmt_count;
@@max_prepared_stmt_count
0
set global max_prepared_stmt_count=10000000000000000;
select @@max_prepared_stmt_count;
@@max_prepared_stmt_count
1048576
set global max_prepared_stmt_count=default;
select @@max_prepared_stmt_count;
@@max_prepared_stmt_count
16382
set @@max_prepared_stmt_count=1;
ERROR HY000: Variable 'max_prepared_stmt_count' is a GLOBAL variable and should be set with SET GLOBAL
set max_prepared_stmt_count=1;
ERROR HY000: Variable 'max_prepared_stmt_count' is a GLOBAL variable and should be set with SET GLOBAL
set local max_prepared_stmt_count=1;
ERROR HY000: Variable 'max_prepared_stmt_count' is a GLOBAL variable and should be set with SET GLOBAL
set local prepared_stmt_count=0;
ERROR HY000: Variable 'prepared_stmt_count' is a GLOBAL variable and should be set with SET GLOBAL
set @@prepared_stmt_count=0;
ERROR HY000: Variable 'prepared_stmt_count' is a GLOBAL variable and should be set with SET GLOBAL
set global prepared_stmt_count=1;
ERROR 42000: Incorrect argument type to variable 'prepared_stmt_count'
set global max_prepared_stmt_count=1;
select @@max_prepared_stmt_count;
@@max_prepared_stmt_count
1
set global max_prepared_stmt_count=0;
select @@max_prepared_stmt_count, @@prepared_stmt_count;
@@max_prepared_stmt_count @@prepared_stmt_count
0 0
prepare stmt from "select 1";
ERROR HY000: Unknown error
select @@prepared_stmt_count;
@@prepared_stmt_count
0
set global max_prepared_stmt_count=1;
prepare stmt from "select 1";
select @@prepared_stmt_count;
@@prepared_stmt_count
1
prepare stmt1 from "select 1";
ERROR HY000: Unknown error
select @@prepared_stmt_count;
@@prepared_stmt_count
1
deallocate prepare stmt;
select @@prepared_stmt_count;
@@prepared_stmt_count
0
prepare stmt from "select 1";
select @@prepared_stmt_count;
@@prepared_stmt_count
1
prepare stmt from "select 2";
select @@prepared_stmt_count;
@@prepared_stmt_count
1
select @@prepared_stmt_count, @@max_prepared_stmt_count;
@@prepared_stmt_count @@max_prepared_stmt_count
1 1
set global max_prepared_stmt_count=0;
prepare stmt from "select 1";
ERROR HY000: Unknown error
execute stmt;
ERROR HY000: Unknown prepared statement handler (stmt) given to EXECUTE
select @@prepared_stmt_count;
@@prepared_stmt_count
0
prepare stmt from "select 1";
ERROR HY000: Unknown error
select @@prepared_stmt_count;
@@prepared_stmt_count
0
set global max_prepared_stmt_count=3;
select @@max_prepared_stmt_count, @@prepared_stmt_count;
@@max_prepared_stmt_count @@prepared_stmt_count
3 0
prepare stmt from "select 1";
prepare stmt from "select 2";
prepare stmt1 from "select 3";
prepare stmt2 from "select 4";
ERROR HY000: Unknown error
prepare stmt2 from "select 4";
ERROR HY000: Unknown error
select @@max_prepared_stmt_count, @@prepared_stmt_count;
@@max_prepared_stmt_count @@prepared_stmt_count
3 3
deallocate prepare stmt;
select @@max_prepared_stmt_count, @@prepared_stmt_count;
@@max_prepared_stmt_count @@prepared_stmt_count
3 0
set global max_prepared_stmt_count= @old_max_prepared_stmt_count;

123
mysql-test/t/ps.test
View file

@ -111,6 +111,9 @@ set @fvar= 123.4567;
prepare stmt1 from @fvar;
drop table t1,t2;
deallocate prepare stmt3;
deallocate prepare stmt4;
deallocate prepare stmt5;
#
# Bug #4105: Server crash on attempt to prepare a statement with character
@ -254,6 +257,7 @@ prepare `ü` from 'select 1234';
execute `ü` ;
set names latin1;
execute `ü`;
deallocate prepare `ü`;
set names default;
@ -803,4 +807,123 @@ execute stmt using @a,@b;
deallocate prepare stmt;
drop table t1;
#
# Bug#16365 Prepared Statements: DoS with too many open statements
# Check that the limit @@max_prpeared_stmt_count works.
#
# Save the old value
set @old_max_prepared_stmt_count= @@max_prepared_stmt_count;
#
# Disable prepared statement protocol: in this test we set
# @@max_prepared_stmt_count to 0 or 1 and would like to test the limit
# manually.
#
--disable_ps_protocol
#
# A. Check that the new variables are present in SHOW VARIABLES list.
#
show variables like 'max_prepared_stmt_count';
show variables like 'prepared_stmt_count';
#
# B. Check that the new variables are selectable.
#
select @@max_prepared_stmt_count, @@prepared_stmt_count;
#
# C. Check that max_prepared_stmt_count is settable (global only),
# whereas prepared_stmt_count is readonly.
#
set global max_prepared_stmt_count=-1;
select @@max_prepared_stmt_count;
set global max_prepared_stmt_count=10000000000000000;
select @@max_prepared_stmt_count;
set global max_prepared_stmt_count=default;
select @@max_prepared_stmt_count;
--error 1229 # ER_GLOBAL_VARIABLE
set @@max_prepared_stmt_count=1;
--error 1229 # ER_GLOBAL_VARIABLE
set max_prepared_stmt_count=1;
--error 1229 # ER_GLOBAL_VARIABLE
set local max_prepared_stmt_count=1;
--error 1229 # ER_GLOBAL_VARIABLE
set local prepared_stmt_count=0;
--error 1229 # ER_GLOBAL_VARIABLE
set @@prepared_stmt_count=0;
--error 1232 # ER_WRONG_TYPE_FOR_VAR
set global prepared_stmt_count=1;
# set to a reasonable limit works
set global max_prepared_stmt_count=1;
select @@max_prepared_stmt_count;
#
# D. Check that the variables actually work.
#
set global max_prepared_stmt_count=0;
select @@max_prepared_stmt_count, @@prepared_stmt_count;
--error 1105 # ER_UNKNOWN_ERROR
prepare stmt from "select 1";
select @@prepared_stmt_count;
set global max_prepared_stmt_count=1;
prepare stmt from "select 1";
select @@prepared_stmt_count;
--error 1105 # ER_UNKNOWN_ERROR
prepare stmt1 from "select 1";
select @@prepared_stmt_count;
deallocate prepare stmt;
select @@prepared_stmt_count;
#
# E. Check that we can prepare a statement with the same name
# successfully, without hitting the limit.
#
prepare stmt from "select 1";
select @@prepared_stmt_count;
prepare stmt from "select 2";
select @@prepared_stmt_count;
#
# F. We can set the max below the current count. In this case no new
# statements should be allowed to prepare.
#
select @@prepared_stmt_count, @@max_prepared_stmt_count;
set global max_prepared_stmt_count=0;
--error 1105 # ER_UNKNOWN_ERROR
prepare stmt from "select 1";
# Result: the old statement is deallocated, the new is not created.
--error 1243 # ER_UNKNOWN_STMT_HANDLER
execute stmt;
select @@prepared_stmt_count;
--error 1105 # ER_UNKNOWN_ERROR
prepare stmt from "select 1";
select @@prepared_stmt_count;
#
# G. Show that the variables are up to date even after a connection with all
# statements in it was terminated.
#
set global max_prepared_stmt_count=3;
select @@max_prepared_stmt_count, @@prepared_stmt_count;
prepare stmt from "select 1";
connect (con1,localhost,root,,);
connection con1;
prepare stmt from "select 2";
prepare stmt1 from "select 3";
--error 1105 # ER_UNKNOWN_ERROR
prepare stmt2 from "select 4";
connection default;
--error 1105 # ER_UNKNOWN_ERROR
prepare stmt2 from "select 4";
select @@max_prepared_stmt_count, @@prepared_stmt_count;
disconnect con1;
connection default;
# Wait for the connection to die: deal with a possible race
deallocate prepare stmt;
let $count= `select @@prepared_stmt_count`;
if ($count)
{
--sleep 2
let $count= `select @@prepared_stmt_count`;
}
select @@max_prepared_stmt_count, @@prepared_stmt_count;
#
# Restore the old value.
#
set global max_prepared_stmt_count= @old_max_prepared_stmt_count;
--enable_ps_protocol
# End of 4.1 tests

4
sql/mysql_priv.h
View file

@ -918,6 +918,7 @@ extern ulong ha_commit_count, ha_rollback_count,table_cache_size;
extern ulong max_connections,max_connect_errors, connect_timeout;
extern ulong slave_net_timeout, slave_trans_retries;
extern ulong max_user_connections;
extern ulong max_prepared_stmt_count, prepared_stmt_count;
extern ulong long_query_count, what_to_log,flush_time;
extern ulong query_buff_size, thread_stack,thread_stack_min;
extern ulong binlog_cache_size, max_binlog_cache_size, open_files_limit;
@ -961,7 +962,8 @@ extern pthread_mutex_t LOCK_mysql_create_db,LOCK_Acl,LOCK_open,
LOCK_error_log, LOCK_delayed_insert, LOCK_uuid_generator,
LOCK_delayed_status, LOCK_delayed_create, LOCK_crypt, LOCK_timezone,
LOCK_slave_list, LOCK_active_mi, LOCK_manager,
LOCK_global_system_variables, LOCK_user_conn;
LOCK_global_system_variables, LOCK_user_conn,
LOCK_prepared_stmt_count;
#ifdef HAVE_OPENSSL
extern pthread_mutex_t LOCK_des_key_file;
#endif

33
sql/mysqld.cc
View file

@ -336,6 +336,22 @@ ulong specialflag=0,opened_tables=0,created_tmp_tables=0,
ulong binlog_cache_use= 0, binlog_cache_disk_use= 0;
ulong max_connections,max_used_connections,
max_connect_errors, max_user_connections = 0;
/*
Limit of the total number of prepared statements in the server.
Is necessary to protect the server against out-of-memory attacks.
*/
ulong max_prepared_stmt_count;
/*
Current total number of prepared statements in the server. This number
is exact, and therefore may not be equal to the difference between
`com_stmt_prepare' and `com_stmt_close' (global status variables), as
the latter ones account for all registered attempts to prepare
a statement (including unsuccessful ones). Prepared statements are
currently connection-local: if the same SQL query text is prepared in
two different connections, this counts as two distinct prepared
statements.
*/
ulong prepared_stmt_count=0;
ulong thread_id=1L,current_pid;
ulong slow_launch_threads = 0, sync_binlog_period;
ulong expire_logs_days = 0;
@ -421,6 +437,14 @@ pthread_mutex_t LOCK_mysql_create_db, LOCK_Acl, LOCK_open, LOCK_thread_count,
LOCK_crypt, LOCK_bytes_sent, LOCK_bytes_received,
LOCK_global_system_variables,
LOCK_user_conn, LOCK_slave_list, LOCK_active_mi;
/*
The below lock protects access to two global server variables:
max_prepared_stmt_count and prepared_stmt_count. These variables
set the limit and hold the current total number of prepared statements
in the server, respectively. As PREPARE/DEALLOCATE rate in a loaded
server may be fairly high, we need a dedicated lock.
*/
pthread_mutex_t LOCK_prepared_stmt_count;
#ifdef HAVE_OPENSSL
pthread_mutex_t LOCK_des_key_file;
#endif
@ -1118,6 +1142,7 @@ static void clean_up_mutexes()
(void) rwlock_destroy(&LOCK_sys_init_connect);
(void) rwlock_destroy(&LOCK_sys_init_slave);
(void) pthread_mutex_destroy(&LOCK_global_system_variables);
(void) pthread_mutex_destroy(&LOCK_prepared_stmt_count);
(void) pthread_cond_destroy(&COND_thread_count);
(void) pthread_cond_destroy(&COND_refresh);
(void) pthread_cond_destroy(&COND_thread_cache);
@ -2635,6 +2660,7 @@ static int init_thread_environment()
(void) pthread_mutex_init(&LOCK_user_conn, MY_MUTEX_INIT_FAST);
(void) pthread_mutex_init(&LOCK_active_mi, MY_MUTEX_INIT_FAST);
(void) pthread_mutex_init(&LOCK_global_system_variables, MY_MUTEX_INIT_FAST);
(void) pthread_mutex_init(&LOCK_prepared_stmt_count, MY_MUTEX_INIT_FAST);
(void) pthread_mutex_init(&LOCK_uuid_generator, MY_MUTEX_INIT_FAST);
#ifdef HAVE_OPENSSL
(void) pthread_mutex_init(&LOCK_des_key_file,MY_MUTEX_INIT_FAST);
@ -4238,7 +4264,8 @@ enum options_mysqld
OPT_MAX_BINLOG_CACHE_SIZE, OPT_MAX_BINLOG_SIZE,
OPT_MAX_CONNECTIONS, OPT_MAX_CONNECT_ERRORS,
OPT_MAX_DELAYED_THREADS, OPT_MAX_HEP_TABLE_SIZE,
OPT_MAX_JOIN_SIZE, OPT_MAX_RELAY_LOG_SIZE, OPT_MAX_SORT_LENGTH,
OPT_MAX_JOIN_SIZE, OPT_MAX_PREPARED_STMT_COUNT,
OPT_MAX_RELAY_LOG_SIZE, OPT_MAX_SORT_LENGTH,
OPT_MAX_SEEKS_FOR_KEY, OPT_MAX_TMP_TABLES, OPT_MAX_USER_CONNECTIONS,
OPT_MAX_LENGTH_FOR_SORT_DATA,
OPT_MAX_WRITE_LOCK_COUNT, OPT_BULK_INSERT_BUFFER_SIZE,
@ -5225,6 +5252,10 @@ The minimum value for this variable is 4096.",
(gptr*) &global_system_variables.max_length_for_sort_data,
(gptr*) &max_system_variables.max_length_for_sort_data, 0, GET_ULONG,
REQUIRED_ARG, 1024, 4, 8192*1024L, 0, 1, 0},
{"max_prepared_stmt_count", OPT_MAX_PREPARED_STMT_COUNT,
"Maximum numbrer of prepared statements in the server.",
(gptr*) &max_prepared_stmt_count, (gptr*) &max_prepared_stmt_count,
0, GET_ULONG, REQUIRED_ARG, 16382, 0, 1*1024*1024, 0, 1, 0},
{"max_relay_log_size", OPT_MAX_RELAY_LOG_SIZE,
"If non-zero: relay log will be rotated automatically when the size exceeds this value; if zero (the default): when the size exceeds max_binlog_size. 0 excepted, the minimum value for this variable is 4096.",
(gptr*) &max_relay_log_size, (gptr*) &max_relay_log_size, 0, GET_ULONG,

42
sql/set_var.cc
View file

@ -118,6 +118,7 @@ static KEY_CACHE *create_key_cache(const char *name, uint length);
void fix_sql_mode_var(THD *thd, enum_var_type type);
static byte *get_error_count(THD *thd);
static byte *get_warning_count(THD *thd);
static byte *get_prepared_stmt_count(THD *thd);
static byte *get_have_innodb(THD *thd);
/*
@ -239,6 +240,10 @@ sys_var_thd_ha_rows sys_sql_max_join_size("sql_max_join_size",
&SV::max_join_size,
fix_max_join_size);
#endif
static sys_var_long_ptr_global
sys_max_prepared_stmt_count("max_prepared_stmt_count",
&max_prepared_stmt_count,
&LOCK_prepared_stmt_count);
sys_var_long_ptr sys_max_relay_log_size("max_relay_log_size",
&max_relay_log_size,
fix_max_relay_log_size);
@ -472,6 +477,9 @@ static sys_var_readonly sys_warning_count("warning_count",
OPT_SESSION,
SHOW_LONG,
get_warning_count);
static sys_var_readonly sys_prepared_stmt_count("prepared_stmt_count",
OPT_GLOBAL, SHOW_LONG,
get_prepared_stmt_count);
/* alias for last_insert_id() to be compatible with Sybase */
#ifdef HAVE_REPLICATION
@ -569,6 +577,7 @@ sys_var *sys_variables[]=
&sys_max_heap_table_size,
&sys_max_join_size,
&sys_max_length_for_sort_data,
&sys_max_prepared_stmt_count,
&sys_max_relay_log_size,
&sys_max_seeks_for_key,
&sys_max_sort_length,
@ -589,6 +598,7 @@ sys_var *sys_variables[]=
&sys_new_mode,
&sys_old_passwords,
&sys_preload_buff_size,
&sys_prepared_stmt_count,
&sys_pseudo_thread_id,
&sys_query_alloc_block_size,
&sys_query_cache_size,
@ -801,6 +811,8 @@ struct show_var_st init_vars[]= {
{sys_max_join_size.name, (char*) &sys_max_join_size, SHOW_SYS},
{sys_max_length_for_sort_data.name, (char*) &sys_max_length_for_sort_data,
SHOW_SYS},
{sys_max_prepared_stmt_count.name, (char*) &sys_max_prepared_stmt_count,
SHOW_SYS},
{sys_max_relay_log_size.name, (char*) &sys_max_relay_log_size, SHOW_SYS},
{sys_max_seeks_for_key.name, (char*) &sys_max_seeks_for_key, SHOW_SYS},
{sys_max_sort_length.name, (char*) &sys_max_sort_length, SHOW_SYS},
@ -838,6 +850,7 @@ struct show_var_st init_vars[]= {
{sys_old_passwords.name, (char*) &sys_old_passwords, SHOW_SYS},
{"open_files_limit", (char*) &open_files_limit, SHOW_LONG},
{"pid_file", (char*) pidfile_name, SHOW_CHAR},
{sys_prepared_stmt_count.name, (char*) &sys_prepared_stmt_count, SHOW_SYS},
{"port", (char*) &mysqld_port, SHOW_INT},
{sys_preload_buff_size.name, (char*) &sys_preload_buff_size, SHOW_SYS},
{"protocol_version", (char*) &protocol_version, SHOW_INT},
@ -1251,29 +1264,40 @@ static void fix_server_id(THD *thd, enum_var_type type)
server_id_supplied = 1;
}
bool sys_var_long_ptr::check(THD *thd, set_var *var)
sys_var_long_ptr::
sys_var_long_ptr(const char *name_arg, ulong *value_ptr,
sys_after_update_func after_update_arg)
:sys_var_long_ptr_global(name_arg, value_ptr,
&LOCK_global_system_variables, after_update_arg)
{}
bool sys_var_long_ptr_global::check(THD *thd, set_var *var)
{
longlong v= var->value->val_int();
var->save_result.ulonglong_value= v < 0 ? 0 : v;
return 0;
}
bool sys_var_long_ptr::update(THD *thd, set_var *var)
bool sys_var_long_ptr_global::update(THD *thd, set_var *var)
{
ulonglong tmp= var->save_result.ulonglong_value;
pthread_mutex_lock(&LOCK_global_system_variables);
pthread_mutex_lock(guard);
if (option_limits)
*value= (ulong) getopt_ull_limit_value(tmp, option_limits);
else
*value= (ulong) tmp;
pthread_mutex_unlock(&LOCK_global_system_variables);
pthread_mutex_unlock(guard);
return 0;
}
void sys_var_long_ptr::set_default(THD *thd, enum_var_type type)
void sys_var_long_ptr_global::set_default(THD *thd, enum_var_type type)
{
pthread_mutex_lock(guard);
*value= (ulong) option_limits->def_value;
pthread_mutex_unlock(guard);
}
@ -2642,6 +2666,14 @@ static byte *get_have_innodb(THD *thd)
}
static byte *get_prepared_stmt_count(THD *thd)
{
pthread_mutex_lock(&LOCK_prepared_stmt_count);
thd->sys_var_tmp.ulong_value= prepared_stmt_count;
pthread_mutex_unlock(&LOCK_prepared_stmt_count);
return (byte*) &thd->sys_var_tmp.ulong_value;
}
/****************************************************************************
Main handling of variables:
- Initialisation

59
sql/set_var.h
View file

@ -47,13 +47,7 @@ public:
#if MYSQL_VERSION_ID < 50000
bool no_support_one_shot;
#endif
sys_var(const char *name_arg)
:name(name_arg), after_update(0)
#if MYSQL_VERSION_ID < 50000
, no_support_one_shot(1)
#endif
{}
sys_var(const char *name_arg,sys_after_update_func func)
sys_var(const char *name_arg, sys_after_update_func func= NULL)
:name(name_arg), after_update(func)
#if MYSQL_VERSION_ID < 50000
, no_support_one_shot(1)
@ -79,15 +73,35 @@ public:
};
class sys_var_long_ptr :public sys_var
/*
A base class for all variables that require its access to
be guarded with a mutex.
*/
class sys_var_global: public sys_var
{
protected:
pthread_mutex_t *guard;
public:
sys_var_global(const char *name_arg, sys_after_update_func after_update_arg,
pthread_mutex_t *guard_arg)
:sys_var(name_arg, after_update_arg), guard(guard_arg) {}
};
/*
A global-only ulong variable that requires its access to be
protected with a mutex.
*/
class sys_var_long_ptr_global: public sys_var_global
{
public:
ulong *value;
sys_var_long_ptr(const char *name_arg, ulong *value_ptr)
:sys_var(name_arg),value(value_ptr) {}
sys_var_long_ptr(const char *name_arg, ulong *value_ptr,
sys_after_update_func func)
:sys_var(name_arg,func), value(value_ptr) {}
sys_var_long_ptr_global(const char *name_arg, ulong *value_ptr,
pthread_mutex_t *guard_arg,
sys_after_update_func after_update_arg= NULL)
:sys_var_global(name_arg, after_update_arg, guard_arg), value(value_ptr) {}
bool check(THD *thd, set_var *var);
bool update(THD *thd, set_var *var);
void set_default(THD *thd, enum_var_type type);
@ -97,6 +111,18 @@ public:
};
/*
A global ulong variable that is protected by LOCK_global_system_variables
*/
class sys_var_long_ptr :public sys_var_long_ptr_global
{
public:
sys_var_long_ptr(const char *name_arg, ulong *value_ptr,
sys_after_update_func after_update_arg= NULL);
};
class sys_var_ulonglong_ptr :public sys_var
{
public:
@ -175,7 +201,7 @@ class sys_var_const_str :public sys_var
public:
char *value; // Pointer to const value
sys_var_const_str(const char *name_arg, const char *value_arg)
:sys_var(name_arg), value((char*) value_arg)
:sys_var(name_arg),value((char*) value_arg)
{}
bool check(THD *thd, set_var *var)
{
@ -221,10 +247,7 @@ public:
class sys_var_thd :public sys_var
{
public:
sys_var_thd(const char *name_arg)
:sys_var(name_arg)
{}
sys_var_thd(const char *name_arg, sys_after_update_func func)
sys_var_thd(const char *name_arg, sys_after_update_func func= NULL)
:sys_var(name_arg,func)
{}
bool check_type(enum_var_type type) { return 0; }

119
sql/sql_class.cc
View file

@ -1616,27 +1616,128 @@ Statement_map::Statement_map() :
NULL,MYF(0));
}
int Statement_map::insert(Statement *statement)
/*
Insert a new statement to the thread-local statement map.
DESCRIPTION
If there was an old statement with the same name, replace it with the
new one. Otherwise, check if max_prepared_stmt_count is not reached yet,
increase prepared_stmt_count, and insert the new statement. It's okay
to delete an old statement and fail to insert the new one.
POSTCONDITIONS
All named prepared statements are also present in names_hash.
Statement names in names_hash are unique.
The statement is added only if prepared_stmt_count < max_prepard_stmt_count
last_found_statement always points to a valid statement or is 0
RETURN VALUE
0 success
1 error: out of resources or max_prepared_stmt_count limit has been
reached. An error is sent to the client, the statement is deleted.
*/
int Statement_map::insert(THD *thd, Statement *statement)
{
int rc= my_hash_insert(&st_hash, (byte *) statement);
if (rc == 0)
last_found_statement= statement;
if (my_hash_insert(&st_hash, (byte*) statement))
{
/*
Delete is needed only in case of an insert failure. In all other
cases hash_delete will also delete the statement.
*/
delete statement;
my_error(ER_OUT_OF_RESOURCES, MYF(0));
goto err_st_hash;
}
if (statement->name.str)
{
/*
If there is a statement with the same name, remove it. It is ok to
If there is a statement with the same name, remove it. It is ok to
remove old and fail to insert new one at the same time.
*/
Statement *old_stmt;
if ((old_stmt= find_by_name(&statement->name)))
erase(old_stmt);
if ((rc= my_hash_insert(&names_hash, (byte*)statement)))
hash_delete(&st_hash, (byte*)statement);
erase(old_stmt);
if (my_hash_insert(&names_hash, (byte*) statement))
{
my_error(ER_OUT_OF_RESOURCES, MYF(0));
goto err_names_hash;
}
}
return rc;
pthread_mutex_lock(&LOCK_prepared_stmt_count);
/*
We don't check that prepared_stmt_count is <= max_prepared_stmt_count
because we would like to allow to lower the total limit
of prepared statements below the current count. In that case
no new statements can be added until prepared_stmt_count drops below
the limit.
*/
if (prepared_stmt_count >= max_prepared_stmt_count)
{
pthread_mutex_unlock(&LOCK_prepared_stmt_count);
my_error(ER_UNKNOWN_ERROR, MYF(0));
goto err_max;
}
prepared_stmt_count++;
pthread_mutex_unlock(&LOCK_prepared_stmt_count);
last_found_statement= statement;
return 0;
err_max:
if (statement->name.str)
hash_delete(&names_hash, (byte*) statement);
err_names_hash:
hash_delete(&st_hash, (byte*) statement);
err_st_hash:
send_error(thd);
return 1;
}
void Statement_map::erase(Statement *statement)
{
if (statement == last_found_statement)
last_found_statement= 0;
if (statement->name.str)
{
hash_delete(&names_hash, (byte *) statement);
}
hash_delete(&st_hash, (byte *) statement);
pthread_mutex_lock(&LOCK_prepared_stmt_count);
DBUG_ASSERT(prepared_stmt_count > 0);
prepared_stmt_count--;
pthread_mutex_unlock(&LOCK_prepared_stmt_count);
}
void Statement_map::reset()
{
/* Must be first, hash_free will reset st_hash.records */
pthread_mutex_lock(&LOCK_prepared_stmt_count);
DBUG_ASSERT(prepared_stmt_count >= st_hash.records);
prepared_stmt_count-= st_hash.records;
pthread_mutex_unlock(&LOCK_prepared_stmt_count);
my_hash_reset(&names_hash);
my_hash_reset(&st_hash);
last_found_statement= 0;
}
Statement_map::~Statement_map()
{
/* Must go first, hash_free will reset st_hash.records */
pthread_mutex_lock(&LOCK_prepared_stmt_count);
DBUG_ASSERT(prepared_stmt_count >= st_hash.records);
prepared_stmt_count-= st_hash.records;
pthread_mutex_unlock(&LOCK_prepared_stmt_count);
hash_free(&names_hash);
hash_free(&st_hash);
}
bool select_dumpvar::send_data(List<Item> &items)
{
List_iterator_fast<Item_func_set_user_var> li(vars);

28
sql/sql_class.h
View file

@ -620,7 +620,7 @@ class Statement_map
public:
Statement_map();
int insert(Statement *statement);
int insert(THD *thd, Statement *statement);
Statement *find_by_name(LEX_STRING *name)
{
@ -642,29 +642,10 @@ public:
}
return last_found_statement;
}
void erase(Statement *statement)
{
if (statement == last_found_statement)
last_found_statement= 0;
if (statement->name.str)
{
hash_delete(&names_hash, (byte *) statement);
}
hash_delete(&st_hash, (byte *) statement);
}
void erase(Statement *statement);
/* Erase all statements (calls Statement destructor) */
void reset()
{
my_hash_reset(&names_hash);
my_hash_reset(&st_hash);
last_found_statement= 0;
}
~Statement_map()
{
hash_free(&names_hash);
hash_free(&st_hash);
}
void reset();
~Statement_map();
private:
HASH st_hash;
HASH names_hash;
@ -932,6 +913,7 @@ public:
{
my_bool my_bool_value;
long long_value;
ulong ulong_value;
} sys_var_tmp;
THD();

8
sql/sql_prepare.cc
View file

@ -1593,10 +1593,12 @@ int mysql_stmt_prepare(THD *thd, char *packet, uint packet_length,
}
}
if (thd->stmt_map.insert(stmt))
if (thd->stmt_map.insert(thd, stmt))
{
delete stmt;
send_error(thd, ER_OUT_OF_RESOURCES);
/*
The error is sent in the insert. The statement itself
will be also deleted there (this is how the hash works).
*/
DBUG_RETURN(1);
}