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Commit d5dbdd98 authored by dlenev@mockturtle.local's avatar dlenev@mockturtle.local
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Merge bk-internal.mysql.com:/home/bk/mysql-5.0-runtime 

into  mockturtle.local:/home/dlenev/src/mysql-5.0-cts-3
parents ad609d6e 8b93e52e
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Showing with 919 additions and 184 deletions
mysql-test/r/create.result
View file @ d5dbdd98
......@@ -769,6 +769,100 @@ t1 CREATE TABLE `t1` (
`i` int(11) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1 MAX_ROWS=4294967295
drop table t1;
create table t1 select * from t2;
ERROR 42S02: Table 'test.t2' doesn't exist
create table t1 select * from t1;
ERROR HY000: You can't specify target table 't1' for update in FROM clause
create table t1 select coalesce('a' collate latin1_swedish_ci,'b' collate latin1_bin);
ERROR HY000: Illegal mix of collations (latin1_swedish_ci,EXPLICIT) and (latin1_bin,EXPLICIT) for operation 'coalesce'
create table t1 (primary key(a)) select "b" as b;
ERROR 42000: Key column 'a' doesn't exist in table
create table t1 (a int);
create table if not exists t1 select 1 as a, 2 as b;
ERROR 21S01: Column count doesn't match value count at row 1
drop table t1;
create table t1 (primary key (a)) (select 1 as a) union all (select 1 as a);
ERROR 23000: Duplicate entry '1' for key 1
create table t1 (i int);
create table t1 select 1 as i;
ERROR 42S01: Table 't1' already exists
create table if not exists t1 select 1 as i;
Warnings:
Note 1050 Table 't1' already exists
select * from t1;
i
1
create table t1 select coalesce('a' collate latin1_swedish_ci,'b' collate latin1_bin);
ERROR HY000: Illegal mix of collations (latin1_swedish_ci,EXPLICIT) and (latin1_bin,EXPLICIT) for operation 'coalesce'
select * from t1;
i
1
alter table t1 add primary key (i);
create table if not exists t1 (select 2 as i) union all (select 2 as i);
ERROR 23000: Duplicate entry '2' for key 1
select * from t1;
i
1
2
drop table t1;
create temporary table t1 (j int);
create table if not exists t1 select 1;
Warnings:
Note 1050 Table 't1' already exists
select * from t1;
j
1
drop temporary table t1;
select * from t1;
ERROR 42S02: Table 'test.t1' doesn't exist
drop table t1;
ERROR 42S02: Unknown table 't1'
create table t1 (i int);
insert into t1 values (1), (2);
lock tables t1 read;
create table t2 select * from t1;
ERROR HY000: Table 't2' was not locked with LOCK TABLES
create table if not exists t2 select * from t1;
ERROR HY000: Table 't2' was not locked with LOCK TABLES
unlock tables;
create table t2 (j int);
lock tables t1 read;
create table t2 select * from t1;
ERROR HY000: Table 't2' was not locked with LOCK TABLES
create table if not exists t2 select * from t1;
ERROR HY000: Table 't2' was not locked with LOCK TABLES
unlock tables;
lock table t1 read, t2 read;
create table t2 select * from t1;
ERROR HY000: Table 't2' was locked with a READ lock and can't be updated
create table if not exists t2 select * from t1;
ERROR HY000: Table 't2' was locked with a READ lock and can't be updated
unlock tables;
lock table t1 read, t2 write;
create table t2 select * from t1;
ERROR 42S01: Table 't2' already exists
create table if not exists t2 select * from t1;
Warnings:
Note 1050 Table 't2' already exists
select * from t1;
i
1
2
unlock tables;
drop table t2;
lock tables t1 read;
create temporary table t2 select * from t1;
create temporary table if not exists t2 select * from t1;
Warnings:
Note 1050 Table 't2' already exists
select * from t2;
i
1
2
1
2
unlock tables;
drop table t1, t2;
create table t1 (upgrade int);
drop table t1;
End of 5.0 tests
mysql-test/r/trigger.result
View file @ d5dbdd98
......@@ -1414,4 +1414,39 @@ id val
DROP TRIGGER trg27006_a_insert;
DROP TRIGGER trg27006_a_update;
drop table t1,t2;
drop table if exists t1, t2, t3;
create table t1 (i int);
create trigger t1_bi before insert on t1 for each row set new.i = 7;
create trigger t1_ai after insert on t1 for each row set @a := 7;
create table t2 (j int);
insert into t2 values (1), (2);
set @a:="";
create table if not exists t1 select * from t2;
Warnings:
Note 1050 Table 't1' already exists
select * from t1;
i
7
7
select @a;
@a
7
drop trigger t1_bi;
drop trigger t1_ai;
create table t3 (isave int);
create trigger t1_bi before insert on t1 for each row insert into t3 values (new.i);
create table if not exists t1 select * from t2;
Warnings:
Note 1050 Table 't1' already exists
select * from t1;
i
7
7
1
2
select * from t3;
isave
1
2
drop table t1, t2, t3;
End of 5.0 tests
mysql-test/t/create.test
View file @ d5dbdd98
......@@ -669,6 +669,117 @@ alter table t1 max_rows=100000000000;
show create table t1;
drop table t1;
#
# Tests for errors happening at various stages of CREATE TABLES ... SELECT
#
# (Also checks that it behaves atomically in the sense that in case
# of error it is automatically dropped if it has not existed before.)
#
# Error during open_and_lock_tables() of tables
--error ER_NO_SUCH_TABLE
create table t1 select * from t2;
# Rather special error which also caught during open tables pahse
--error ER_UPDATE_TABLE_USED
create table t1 select * from t1;
# Error which happens before select_create::prepare()
--error ER_CANT_AGGREGATE_2COLLATIONS
create table t1 select coalesce('a' collate latin1_swedish_ci,'b' collate latin1_bin);
# Error during table creation
--error ER_KEY_COLUMN_DOES_NOT_EXITS
create table t1 (primary key(a)) select "b" as b;
# Error in select_create::prepare() which is not related to table creation
create table t1 (a int);
--error ER_WRONG_VALUE_COUNT_ON_ROW
create table if not exists t1 select 1 as a, 2 as b;
drop table t1;
# Finally error which happens during insert
--error ER_DUP_ENTRY
create table t1 (primary key (a)) (select 1 as a) union all (select 1 as a);
# What happens if table already exists ?
create table t1 (i int);
--error ER_TABLE_EXISTS_ERROR
create table t1 select 1 as i;
create table if not exists t1 select 1 as i;
select * from t1;
# Error before select_create::prepare()
--error ER_CANT_AGGREGATE_2COLLATIONS
create table t1 select coalesce('a' collate latin1_swedish_ci,'b' collate latin1_bin);
select * from t1;
# Error which happens during insertion of rows
alter table t1 add primary key (i);
--error ER_DUP_ENTRY
create table if not exists t1 (select 2 as i) union all (select 2 as i);
select * from t1;
drop table t1;
# Base vs temporary tables dillema (a.k.a. bug#24508 "Inconsistent
# results of CREATE TABLE ... SELECT when temporary table exists").
# In this situation we either have to create non-temporary table and
# insert data in it or insert data in temporary table without creation
# of permanent table. Since currently temporary tables always shadow
# permanent tables we adopt second approach.
create temporary table t1 (j int);
create table if not exists t1 select 1;
select * from t1;
drop temporary table t1;
--error ER_NO_SUCH_TABLE
select * from t1;
--error ER_BAD_TABLE_ERROR
drop table t1;
#
# CREATE TABLE ... SELECT and LOCK TABLES
#
# There is little sense in using CREATE TABLE ... SELECT under
# LOCK TABLES as it mostly does not work. At least we check that
# the server doesn't crash, hang and produces sensible errors.
# Includes test for bug #20662 "Infinite loop in CREATE TABLE
# IF NOT EXISTS ... SELECT with locked tables".
create table t1 (i int);
insert into t1 values (1), (2);
lock tables t1 read;
--error ER_TABLE_NOT_LOCKED
create table t2 select * from t1;
--error ER_TABLE_NOT_LOCKED
create table if not exists t2 select * from t1;
unlock tables;
create table t2 (j int);
lock tables t1 read;
--error ER_TABLE_NOT_LOCKED
create table t2 select * from t1;
# This should not be ever allowed as it will undermine
# lock-all-at-once approach
--error ER_TABLE_NOT_LOCKED
create table if not exists t2 select * from t1;
unlock tables;
lock table t1 read, t2 read;
--error ER_TABLE_NOT_LOCKED_FOR_WRITE
create table t2 select * from t1;
--error ER_TABLE_NOT_LOCKED_FOR_WRITE
create table if not exists t2 select * from t1;
unlock tables;
lock table t1 read, t2 write;
--error ER_TABLE_EXISTS_ERROR
create table t2 select * from t1;
# This is the only case which really works.
create table if not exists t2 select * from t1;
select * from t1;
unlock tables;
drop table t2;
# OTOH CREATE TEMPORARY TABLE ... SELECT should work
# well under LOCK TABLES.
lock tables t1 read;
create temporary table t2 select * from t1;
create temporary table if not exists t2 select * from t1;
select * from t2;
unlock tables;
drop table t1, t2;
#
# Bug#21772: can not name a column 'upgrade' when create a table
#
......
mysql-test/t/trigger.test
View file @ d5dbdd98
......@@ -1737,4 +1737,30 @@ DROP TRIGGER trg27006_a_insert;
DROP TRIGGER trg27006_a_update;
drop table t1,t2;
#
# Bug #20903 "Crash when using CREATE TABLE .. SELECT and triggers"
#
--disable_warnings
drop table if exists t1, t2, t3;
--enable_warnings
create table t1 (i int);
create trigger t1_bi before insert on t1 for each row set new.i = 7;
create trigger t1_ai after insert on t1 for each row set @a := 7;
create table t2 (j int);
insert into t2 values (1), (2);
set @a:="";
create table if not exists t1 select * from t2;
select * from t1;
select @a;
# Let us check that trigger that involves table also works ok.
drop trigger t1_bi;
drop trigger t1_ai;
create table t3 (isave int);
create trigger t1_bi before insert on t1 for each row insert into t3 values (new.i);
create table if not exists t1 select * from t2;
select * from t1;
select * from t3;
drop table t1, t2, t3;
--echo End of 5.0 tests
sql/lock.cc
View file @ d5dbdd98
......@@ -853,7 +853,6 @@ int lock_table_name(THD *thd, TABLE_LIST *table_list)
TABLE *table;
char key[MAX_DBKEY_LENGTH];
char *db= table_list->db;
int table_in_key_offset;
uint key_length;
HASH_SEARCH_STATE state;
DBUG_ENTER("lock_table_name");
......@@ -861,10 +860,8 @@ int lock_table_name(THD *thd, TABLE_LIST *table_list)
safe_mutex_assert_owner(&LOCK_open);
table_in_key_offset= strmov(key, db) - key + 1;
key_length= (uint)(strmov(key + table_in_key_offset, table_list->table_name)
- key) + 1;
key_length= (uint)(strmov(strmov(key, db) + 1, table_list->table_name) -
key) + 1;
/* Only insert the table if we haven't insert it already */
for (table=(TABLE*) hash_first(&open_cache, (byte*)key, key_length, &state);
......@@ -873,29 +870,11 @@ int lock_table_name(THD *thd, TABLE_LIST *table_list)
if (table->in_use == thd)
DBUG_RETURN(0);
/*
Create a table entry with the right key and with an old refresh version
Note that we must use my_malloc() here as this is freed by the table
cache
*/
if (!(table= (TABLE*) my_malloc(sizeof(*table)+key_length,
MYF(MY_WME | MY_ZEROFILL))))
DBUG_RETURN(-1);
table->s= &table->share_not_to_be_used;
memcpy((table->s->table_cache_key= (char*) (table+1)), key, key_length);
table->s->db= table->s->table_cache_key;
table->s->table_name= table->s->table_cache_key + table_in_key_offset;
table->s->key_length=key_length;
table->in_use=thd;
table->locked_by_name=1;
table_list->table=table;
if (my_hash_insert(&open_cache, (byte*) table))
{
my_free((gptr) table,MYF(0));
if (!(table= table_cache_insert_placeholder(thd, key, key_length)))
DBUG_RETURN(-1);
}
table_list->table= table;
/* Return 1 if table is in use */
DBUG_RETURN(test(remove_table_from_cache(thd, db, table_list->table_name,
RTFC_NO_FLAG)));
......
sql/mysql_priv.h
View file @ d5dbdd98
......@@ -676,6 +676,8 @@ struct Query_cache_query_flags
#define query_cache_invalidate_by_MyISAM_filename_ref NULL
#endif /*HAVE_QUERY_CACHE*/
uint build_table_path(char *buff, size_t bufflen, const char *db,
const char *table, const char *ext);
bool mysql_create_db(THD *thd, char *db, HA_CREATE_INFO *create, bool silent);
bool mysql_alter_db(THD *thd, const char *db, HA_CREATE_INFO *create);
bool mysql_rm_db(THD *thd,char *db,bool if_exists, bool silent);
......@@ -858,12 +860,14 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create);
TABLE *open_ltable(THD *thd, TABLE_LIST *table_list, thr_lock_type update);
TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT* mem,
bool *refresh, uint flags);
bool reopen_name_locked_table(THD* thd, TABLE_LIST* table);
bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list, bool link_in);
TABLE *table_cache_insert_placeholder(THD *thd, const char *key,
uint key_length);
bool table_cache_has_open_placeholder(THD *thd, const char *db,
const char *table_name);
TABLE *find_locked_table(THD *thd, const char *db,const char *table_name);
bool reopen_table(TABLE *table,bool locked);
bool reopen_tables(THD *thd,bool get_locks,bool in_refresh);
void close_old_data_files(THD *thd, TABLE *table, bool abort_locks,
bool send_refresh);
bool close_data_tables(THD *thd,const char *db, const char *table_name);
bool wait_for_tables(THD *thd);
bool table_is_used(TABLE *table, bool wait_for_name_lock);
......@@ -1019,6 +1023,8 @@ void add_join_natural(TABLE_LIST *a,TABLE_LIST *b,List<String> *using_fields,
SELECT_LEX *lex);
bool add_proc_to_list(THD *thd, Item *item);
TABLE *unlink_open_table(THD *thd,TABLE *list,TABLE *find);
void drop_open_table(THD *thd, TABLE *table, const char *db_name,
const char *table_name);
void update_non_unique_table_error(TABLE_LIST *update,
const char *operation,
TABLE_LIST *duplicate);
......@@ -1271,7 +1277,7 @@ extern double log_01[32];
extern ulonglong log_10_int[20];
extern ulonglong keybuff_size;
extern ulonglong thd_startup_options;
extern ulong refresh_version,flush_version, thread_id;
extern ulong flush_version, thread_id;
extern ulong binlog_cache_use, binlog_cache_disk_use;
extern ulong aborted_threads,aborted_connects;
extern ulong delayed_insert_timeout;
......@@ -1445,7 +1451,7 @@ MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **table, uint count,
#define MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK 0x0001
#define MYSQL_LOCK_IGNORE_FLUSH 0x0002
#define MYSQL_LOCK_NOTIFY_IF_NEED_REOPEN 0x0004
#define MYSQL_OPEN_IGNORE_LOCKED_TABLES 0x0008
#define MYSQL_OPEN_TEMPORARY_ONLY 0x0008
void mysql_unlock_tables(THD *thd, MYSQL_LOCK *sql_lock);
void mysql_unlock_read_tables(THD *thd, MYSQL_LOCK *sql_lock);
......
sql/sql_base.cc
View file @ d5dbdd98
......@@ -94,6 +94,8 @@ static bool open_new_frm(THD *thd, const char *path, const char *alias,
uint db_stat, uint prgflag,
uint ha_open_flags, TABLE *outparam,
TABLE_LIST *table_desc, MEM_ROOT *mem_root);
static void close_old_data_files(THD *thd, TABLE *table, bool morph_locks,
bool send_refresh);
extern "C" byte *table_cache_key(const byte *record,uint *length,
my_bool not_used __attribute__((unused)))
......@@ -374,7 +376,21 @@ bool close_cached_tables(THD *thd, bool if_wait_for_refresh,
for (uint idx=0 ; idx < open_cache.records ; idx++)
{
TABLE *table=(TABLE*) hash_element(&open_cache,idx);
if ((table->s->version) < refresh_version && table->db_stat)
/*
Note that we wait here only for tables which are actually open, and
not for placeholders with TABLE::open_placeholder set. Waiting for
latter will cause deadlock in the following scenario, for example:
conn1: lock table t1 write;
conn2: lock table t2 write;
conn1: flush tables;
conn2: flush tables;
It also does not make sense to wait for those of placeholders that
are employed by CREATE TABLE as in this case table simply does not
exist yet.
*/
if (table->needs_reopen_or_name_lock() && table->db_stat)
{
found=1;
DBUG_PRINT("signal", ("Waiting for COND_refresh"));
......@@ -616,10 +632,10 @@ bool close_thread_table(THD *thd, TABLE **table_ptr)
TABLE *table= *table_ptr;
DBUG_ENTER("close_thread_table");
DBUG_ASSERT(table->key_read == 0);
DBUG_ASSERT(table->file->inited == handler::NONE);
DBUG_ASSERT(!table->file || table->file->inited == handler::NONE);
*table_ptr=table->next;
if (table->s->version != refresh_version ||
if (table->needs_reopen_or_name_lock() ||
thd->version != refresh_version || !table->db_stat)
{
VOID(hash_delete(&open_cache,(byte*) table));
......@@ -627,6 +643,12 @@ bool close_thread_table(THD *thd, TABLE **table_ptr)
}
else
{
/*
Open placeholders have TABLE::db_stat set to 0, so they should be
handled by the first alternative.
*/
DBUG_ASSERT(!table->open_placeholder);
if (table->s->flush_version != flush_version)
{
table->s->flush_version= flush_version;
......@@ -1114,6 +1136,43 @@ TABLE *unlink_open_table(THD *thd, TABLE *list, TABLE *find)
}
/**
@brief Auxiliary routine which closes and drops open table.
@param thd Thread handle
@param table TABLE object for table to be dropped
@param db_name Name of database for this table
@param table_name Name of this table
@note This routine assumes that table to be closed is open only
by calling thread so we needn't wait until other threads
will close the table. Also unless called under implicit or
explicit LOCK TABLES mode it assumes that table to be
dropped is already unlocked. In the former case it will
also remove lock on the table. But one should not rely on
this behaviour as it may change in future.
*/
void drop_open_table(THD *thd, TABLE *table, const char *db_name,
const char *table_name)
{
if (table->s->tmp_table)
close_temporary_table(thd, db_name, table_name);
else
{
enum db_type table_type= table->s->db_type;
VOID(pthread_mutex_lock(&LOCK_open));
/*
unlink_open_table() also tells threads waiting for refresh or close
that something has happened.
*/
thd->open_tables= unlink_open_table(thd, thd->open_tables, table);
quick_rm_table(table_type, db_name, table_name);
VOID(pthread_mutex_unlock(&LOCK_open));
}
}
/*
When we call the following function we must have a lock on
LOCK_open ; This lock will be unlocked on return.
......@@ -1152,6 +1211,11 @@ void wait_for_refresh(THD *thd)
table_list TABLE_LIST object for table to be open, TABLE_LIST::table
member should point to TABLE object which was used for
name-locking.
link_in TRUE - if TABLE object for table to be opened should be
linked into THD::open_tables list.
FALSE - placeholder used for name-locking is already in
this list so we only need to preserve TABLE::next
pointer.
NOTE
This function assumes that its caller already acquired LOCK_open mutex.
......@@ -1161,7 +1225,7 @@ void wait_for_refresh(THD *thd)
TRUE - Error
*/
bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list)
bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list, bool link_in)
{
TABLE *table= table_list->table;
TABLE_SHARE *share;
......@@ -1199,12 +1263,33 @@ bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list)
share= table->s;
share->db= share->table_cache_key;
share->key_length=key_length;
/*
We want to prevent other connections from opening this table until end
of statement as it is likely that modifications of table's metadata are
not yet finished (for example CREATE TRIGGER have to change .TRG file,
or we might want to drop table if CREATE TABLE ... SELECT fails).
This also allows us to assume that no other connection will sneak in
before we will get table-level lock on this table.
*/
share->version=0;
share->flush_version=0;
table->in_use = thd;
check_unused();
table->next = thd->open_tables;
thd->open_tables = table;
if (link_in)
{
table->next= thd->open_tables;
thd->open_tables= table;
}
else
{
/*
TABLE object should be already in THD::open_tables list so we just
need to set TABLE::next correctly.
*/
table->next= orig_table.next;
}
table->tablenr=thd->current_tablenr++;
table->used_fields=0;
table->const_table=0;
......@@ -1216,6 +1301,167 @@ bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list)
}
/**
@brief Create and insert into table cache placeholder for table
which will prevent its opening (or creation) (a.k.a lock
table name).
@param thd Thread context
@param key Table cache key for name to be locked
@param key_length Table cache key length
@return Pointer to TABLE object used for name locking or 0 in
case of failure.
*/
TABLE *table_cache_insert_placeholder(THD *thd, const char *key,
uint key_length)
{
TABLE *table;
char *key_buff;
DBUG_ENTER("table_cache_insert_placeholder");
safe_mutex_assert_owner(&LOCK_open);
/*
Create a table entry with the right key and with an old refresh version
Note that we must use my_multi_malloc() here as this is freed by the
table cache
*/
if (!my_multi_malloc(MYF(MY_WME | MY_ZEROFILL),
&table, sizeof(*table),
&key_buff, key_length,
NULL))
DBUG_RETURN(NULL);
table->s= &table->share_not_to_be_used;
memcpy(key_buff, key, key_length);
table->s->table_cache_key= key_buff;
table->s->db= table->s->table_cache_key;
table->s->table_name= table->s->table_cache_key + strlen(table->s->db) + 1;
table->s->key_length= key_length;
table->in_use= thd;
table->locked_by_name= 1;
if (my_hash_insert(&open_cache, (byte*)table))
{
my_free((gptr) table, MYF(0));
DBUG_RETURN(NULL);
}
DBUG_RETURN(table);
}
/**
@brief Check if table cache contains an open placeholder for the
table and if this placeholder was created by another thread.
@param thd Thread context
@param db Name of database for table in question
@param table_name Table name
@note The presence of open placeholder indicates that either some
other thread is trying to create table in question and obtained
an exclusive name-lock on it or that this table already exists
and is being flushed at the moment.
@note One should acquire LOCK_open mutex before calling this function.
@note This function is a hack which was introduced in 5.0 only to
minimize code changes. It doesn't present in 5.1.
@retval TRUE Table cache contains open placeholder for the table
which was created by some other thread.
@retval FALSE Otherwise.
*/
bool table_cache_has_open_placeholder(THD *thd, const char *db,
const char *table_name)
{
char key[MAX_DBKEY_LENGTH];
uint key_length;
HASH_SEARCH_STATE state;
TABLE *search;
DBUG_ENTER("table_cache_has_open_placeholder");
safe_mutex_assert_owner(&LOCK_open);
key_length=(uint) (strmov(strmov(key,db)+1,table_name)-key)+1;
for (search= (TABLE*) hash_first(&open_cache, (byte*) key, key_length,
&state);
search ;
search= (TABLE*) hash_next(&open_cache, (byte*) key, key_length,
&state))
{
if (search->in_use == thd)
continue;
if (search->open_placeholder)
DBUG_RETURN(1);
}
DBUG_RETURN(0);
}
/**
@brief Check that table exists on disk or in some storage engine.
@param thd Thread context
@param table Table list element
@param exists[out] Out parameter which is set to TRUE if table
exists and to FALSE otherwise.
@note This function assumes that caller owns LOCK_open mutex.
It also assumes that the fact that there are no name-locks
on the table was checked beforehand.
@note If there is no .FRM file for the table but it exists in one
of engines (e.g. it was created on another node of NDB cluster)
this function will fetch and create proper .FRM file for it.
@retval TRUE Some error occured
@retval FALSE No error. 'exists' out parameter set accordingly.
*/
bool check_if_table_exists(THD *thd, TABLE_LIST *table, bool *exists)
{
char path[FN_REFLEN];
int rc;
DBUG_ENTER("check_if_table_exists");
safe_mutex_assert_owner(&LOCK_open);
*exists= TRUE;
build_table_path(path, sizeof(path), table->db, table->table_name, reg_ext);
if (!access(path, F_OK))
DBUG_RETURN(FALSE);
/* .FRM file doesn't exist. Check if some engine can provide it. */
rc= ha_create_table_from_engine(thd, table->db, table->table_name);
if (rc < 0)
{
/* Table does not exists in engines as well. */
*exists= FALSE;
DBUG_RETURN(FALSE);
}
else if (!rc)
{
/* Table exists in some engine and .FRM for it was created. */
DBUG_RETURN(FALSE);
}
else /* (rc > 0) */
{
my_printf_error(ER_UNKNOWN_ERROR, "Failed to open '%-.64s', error while "
"unpacking from engine", MYF(0), table->table_name);
DBUG_RETURN(TRUE);
}
}
/*
Open a table.
......@@ -1231,12 +1477,17 @@ bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list)
MYSQL_LOCK_IGNORE_FLUSH - Open table even if
someone has done a flush or namelock on it.
No version number checking is done.
MYSQL_OPEN_IGNORE_LOCKED_TABLES - Open table
ignoring set of locked tables and prelocked mode.
MYSQL_OPEN_TEMPORARY_ONLY - Open only temporary
table not the base table or view.
IMPLEMENTATION
Uses a cache of open tables to find a table not in use.
If table list element for the table to be opened has "create" flag
set and table does not exist, this function will automatically insert
a placeholder for exclusive name lock into the open tables cache and
will return the TABLE instance that corresponds to this placeholder.
RETURN
NULL Open failed. If refresh is set then one should close
all other tables and retry the open.
......@@ -1305,6 +1556,12 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
}
}
if (flags & MYSQL_OPEN_TEMPORARY_ONLY)
{
my_error(ER_NO_SUCH_TABLE, MYF(0), table_list->db, table_list->table_name);
DBUG_RETURN(0);
}
/*
The table is not temporary - if we're in pre-locked or LOCK TABLES
mode, let's try to find the requested table in the list of pre-opened
......@@ -1312,8 +1569,7 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
open not pre-opened tables in pre-locked/LOCK TABLES mode.
TODO: move this block into a separate function.
*/
if (!(flags & MYSQL_OPEN_IGNORE_LOCKED_TABLES) &&
(thd->locked_tables || thd->prelocked_mode))
if (thd->locked_tables || thd->prelocked_mode)
{ // Using table locks
TABLE *best_table= 0;
int best_distance= INT_MIN;
......@@ -1495,7 +1751,7 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
c1: name lock t2; -- blocks
c2: open t1; -- blocks
*/
if (table->s->version != refresh_version)
if (table->needs_reopen_or_name_lock())
{
DBUG_PRINT("note",
("Found table '%s.%s' with different refresh version",
......@@ -1507,6 +1763,14 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
continue;
}
/* Avoid self-deadlocks by detecting self-dependencies. */
if (table->open_placeholder && table->in_use == thd)
{
VOID(pthread_mutex_unlock(&LOCK_open));
my_error(ER_UPDATE_TABLE_USED, MYF(0), table->s->table_name);
DBUG_RETURN(0);
}
/*
Back off, part 1: mark the table as "unused" for the
purpose of name-locking by setting table->db_stat to 0. Do
......@@ -1523,6 +1787,14 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
and wait till the operation is complete: when any
operation that juggles with table->s->version completes,
it broadcasts COND_refresh condition variable.
If 'old' table we met is in use by current thread we return
without waiting since in this situation it's this thread
which is responsible for broadcasting on COND_refresh
(and this was done already in close_old_data_files()).
Good example of such situation is when we have statement
that needs two instances of table and FLUSH TABLES comes
after we open first instance but before we open second
instance.
*/
if (table->in_use != thd)
{
......@@ -1564,6 +1836,40 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
while (open_cache.records > table_cache_size && unused_tables)
VOID(hash_delete(&open_cache,(byte*) unused_tables)); /* purecov: tested */
if (table_list->create)
{
bool exists;
if (check_if_table_exists(thd, table_list, &exists))
{
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(NULL);
}
if (!exists)
{
/*
Table to be created, so we need to create placeholder in table-cache.
*/
if (!(table= table_cache_insert_placeholder(thd, key, key_length)))
{
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(NULL);
}
/*
Link placeholder to the open tables list so it will be automatically
removed once tables are closed. Also mark it so it won't be ignored
by other trying to take name-lock.
*/
table->open_placeholder= 1;
table->next= thd->open_tables;
thd->open_tables= table;
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(table);
}
/* Table exists. Let us try to open it. */
}
/* make a new table */
if (!(table=(TABLE*) my_malloc(sizeof(*table),MYF(MY_WME))))
{
......@@ -1794,9 +2100,24 @@ bool close_data_tables(THD *thd,const char *db, const char *table_name)
}
/*
Reopen all tables with closed data files
One should have lock on LOCK_open when calling this
/**
@brief Reopen all tables with closed data files.
@param thd Thread context
@param get_locks Should we get locks after reopening tables ?
@param in_refresh Are we in FLUSH TABLES ? TODO: It seems that
we can remove this parameter.
@note Since this function can't properly handle prelocking and
create placeholders it should be used in very special
situations like FLUSH TABLES or ALTER TABLE. In general
case one should just repeat open_tables()/lock_tables()
combination when one needs tables to be reopened (for
example see open_and_lock_tables()).
@note One should have lock on LOCK_open when calling this.
@return FALSE in case of success, TRUE - otherwise.
*/
bool reopen_tables(THD *thd,bool get_locks,bool in_refresh)
......@@ -1841,7 +2162,7 @@ bool reopen_tables(THD *thd,bool get_locks,bool in_refresh)
if (in_refresh)
{
table->s->version=0;
table->locked_by_flush=0;
table->open_placeholder= 0;
}
}
}
......@@ -1867,35 +2188,71 @@ bool reopen_tables(THD *thd,bool get_locks,bool in_refresh)
DBUG_RETURN(error);
}
/*
Close handlers for tables in list, but leave the TABLE structure
intact so that we can re-open these quickly
abort_locks is set if called from flush_tables.
/**
@brief Close handlers for tables in list, but leave the TABLE structure
intact so that we can re-open these quickly.
@param thd Thread context
@param table Head of the list of TABLE objects
@param morph_locks TRUE - remove locks which we have on tables being closed
but ensure that no DML or DDL will sneak in before
we will re-open the table (i.e. temporarily morph
our table-level locks into name-locks).
FALSE - otherwise
@param send_refresh Should we awake waiters even if we didn't close any tables?
*/
void close_old_data_files(THD *thd, TABLE *table, bool abort_locks,
void close_old_data_files(THD *thd, TABLE *table, bool morph_locks,
bool send_refresh)
{
DBUG_ENTER("close_old_data_files");
bool found=send_refresh;
for (; table ; table=table->next)
{
if (table->s->version != refresh_version)
if (table->needs_reopen_or_name_lock())
{
found=1;
if (!abort_locks) // If not from flush tables
/*
Note that it is safe to update version even for open placeholders
as later in this function we reset TABLE::open_placeholder and thus
effectively remove them from the table cache.
*/
if (!morph_locks) // If not from flush tables
table->s->version= refresh_version; // Let other threads use table
if (table->db_stat)
{
if (abort_locks)
{
mysql_lock_abort(thd,table); // Close waiting threads
mysql_lock_remove(thd, thd->locked_tables,table);
table->locked_by_flush=1; // Will be reopened with locks
}
if (morph_locks)
{
/*
Wake up threads waiting for table-level lock on this table
so they won't sneak in when we will temporarily remove our
lock on it. This will also give them a chance to close their
instances of this table.
*/
mysql_lock_abort(thd, table);
mysql_lock_remove(thd, thd->locked_tables, table);
/*
We want to protect the table from concurrent DDL operations
(like RENAME TABLE) until we will re-open and re-lock it.
*/
table->open_placeholder= 1;
}
table->file->close();
table->db_stat=0;
}
else if (table->open_placeholder)
{
/*
We come here only in close-for-back-off scenario. So we have to
"close" create placeholder here to avoid deadlocks (for example,
in case of concurrent execution of CREATE TABLE t1 SELECT * FROM t2
and RENAME TABLE t2 TO t1). In close-for-re-open scenario we will
probably want to let it stay.
*/
DBUG_ASSERT(!morph_locks);
table->open_placeholder= 0;
}
}
}
if (found)
......@@ -1923,9 +2280,8 @@ bool table_is_used(TABLE *table, bool wait_for_name_lock)
search= (TABLE*) hash_next(&open_cache, (byte*) key,
key_length, &state))
{
if (search->locked_by_flush ||
search->locked_by_name && wait_for_name_lock ||
search->db_stat && search->s->version < refresh_version)
if (search->locked_by_name && wait_for_name_lock ||
search->is_name_opened() && search->needs_reopen_or_name_lock())
return 1; // Table is used
}
} while ((table=table->next));
......@@ -5661,7 +6017,7 @@ bool remove_table_from_cache(THD *thd, const char *db, const char *table_name,
else if (in_use != thd)
{
in_use->some_tables_deleted=1;
if (table->db_stat)
if (table->is_name_opened())
{
DBUG_PRINT("info", ("Found another active instance of the table"));
result=1;
......
sql/sql_handler.cc
View file @ d5dbdd98
......@@ -670,7 +670,7 @@ int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags,
while (*table_ptr)
{
if ((mode_flags & MYSQL_HA_FLUSH_ALL) ||
((*table_ptr)->s->version != refresh_version))
(*table_ptr)->needs_reopen_or_name_lock())
{
/* The first time it is required, lock for close_thread_table(). */
if (! did_lock && ! is_locked)
......@@ -771,15 +771,22 @@ void mysql_ha_mark_tables_for_reopen(THD *thd, TABLE *table)
safe_mutex_assert_owner(&LOCK_open);
for (; table; table= table->next)
{
TABLE_LIST *hash_tables;
if ((hash_tables= (TABLE_LIST*) hash_search(&thd->handler_tables_hash,
(byte*) table->alias,
strlen(table->alias) + 1)))
/*
Some elements in open table list, for example placeholders used for
name-locking, can have alias set to 0.
*/
if (table->alias)
{
/* Mark table as ready for reopen. */
hash_tables->table= NULL;
/* End open index/table scans. */
table->file->ha_index_or_rnd_end();
TABLE_LIST *hash_tables;
if ((hash_tables= (TABLE_LIST*) hash_search(&thd->handler_tables_hash,
(byte*) table->alias,
strlen(table->alias) + 1)))
{
/* Mark table as ready for reopen. */
hash_tables->table= NULL;
/* End open index/table scans. */
table->file->ha_index_or_rnd_end();
}
}
}
DBUG_VOID_RETURN;
......
sql/sql_insert.cc
View file @ d5dbdd98
......@@ -2255,7 +2255,7 @@ bool Delayed_insert::handle_inserts(void)
thd.proc_info="insert";
max_rows= delayed_insert_limit;
if (thd.killed || table->s->version != refresh_version)
if (thd.killed || table->needs_reopen_or_name_lock())
{
thd.killed= THD::KILL_CONNECTION;
max_rows= ~(ulong)0; // Do as much as possible
......@@ -2867,8 +2867,8 @@ bool select_insert::send_eof()
***************************************************************************/
/*
Create table from lists of fields and items (or open existing table
with same name).
Create table from lists of fields and items (or just return TABLE
object for pre-opened existing table).
SYNOPSIS
create_table_from_items()
......@@ -2883,18 +2883,24 @@ bool select_insert::send_eof()
of fields for the table (corresponding fields will
be added to the end of alter_info->create_list)
lock out Pointer to the MYSQL_LOCK object for table created
(open) will be returned in this parameter. Since
this table is not included in THD::lock caller is
responsible for explicitly unlocking this table.
(or open temporary table) will be returned in this
parameter. Since this table is not included in
THD::lock caller is responsible for explicitly
unlocking this table.
NOTES
If 'create_info->options' bitmask has HA_LEX_CREATE_IF_NOT_EXISTS
flag and table with name provided already exists then this function will
simply open existing table.
Also note that create, open and lock sequence in this function is not
atomic and thus contains gap for deadlock and can cause other troubles.
Since this function contains some logic specific to CREATE TABLE ... SELECT
it should be changed before it can be used in other contexts.
This function behaves differently for base and temporary tables:
- For base table we assume that either table exists and was pre-opened
and locked at open_and_lock_tables() stage (and in this case we just
emit error or warning and return pre-opened TABLE object) or special
placeholder was put in table cache that guarantees that this table
won't be created or opened until the placeholder will be removed
(so there is an exclusive lock on this table).
- We don't pre-open existing temporary table, instead we either open
or create and then open table in this function.
Since this function contains some logic specific to CREATE TABLE ...
SELECT it should be changed before it can be used in other contexts.
RETURN VALUES
non-zero Pointer to TABLE object for table created or opened
......@@ -2917,6 +2923,25 @@ static TABLE *create_table_from_items(THD *thd, HA_CREATE_INFO *create_info,
bool not_used;
DBUG_ENTER("create_table_from_items");
DBUG_EXECUTE_IF("sleep_create_select_before_check_if_exists", my_sleep(6000000););
if (!(create_info->options & HA_LEX_CREATE_TMP_TABLE) &&
create_table->table->db_stat)
{
/* Table already exists and was open at open_and_lock_tables() stage. */
if (create_info->options & HA_LEX_CREATE_IF_NOT_EXISTS)
{
create_info->table_existed= 1; // Mark that table existed
push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
ER_TABLE_EXISTS_ERROR, ER(ER_TABLE_EXISTS_ERROR),
create_table->table_name);
DBUG_RETURN(create_table->table);
}
my_error(ER_TABLE_EXISTS_ERROR, MYF(0), create_table->table_name);
DBUG_RETURN(0);
}
tmp_table.alias= 0;
tmp_table.timestamp_field= 0;
tmp_table.s= &tmp_table.share_not_to_be_used;
......@@ -2945,8 +2970,15 @@ static TABLE *create_table_from_items(THD *thd, HA_CREATE_INFO *create_info,
cr_field->flags &= ~NOT_NULL_FLAG;
alter_info->create_list.push_back(cr_field);
}
DBUG_EXECUTE_IF("sleep_create_select_before_create", my_sleep(6000000););
/*
create and lock table
Create and lock table.
Note that we either creating (or opening existing) temporary table or
creating base table on which name we have exclusive lock. So code below
should not cause deadlocks or races.
We don't log the statement, it will be logged later.
......@@ -2956,59 +2988,70 @@ static TABLE *create_table_from_items(THD *thd, HA_CREATE_INFO *create_info,
don't want to delete from it) 2) it would be written before the CREATE
TABLE, which is a wrong order. So we keep binary logging disabled when we
open_table().
NOTE: By locking table which we just have created (or for which we just have
have found that it already exists) separately from other tables used by the
statement we create potential window for deadlock.
TODO: create and open should be done atomic !
*/
{
tmp_disable_binlog(thd);
if (!mysql_create_table(thd, create_table->db, create_table->table_name,
create_info, alter_info, 0, select_field_count))
{
/*
If we are here in prelocked mode we either create temporary table
or prelocked mode is caused by the SELECT part of this statement.
*/
DBUG_ASSERT(!thd->prelocked_mode ||
create_info->options & HA_LEX_CREATE_TMP_TABLE ||
thd->lex->requires_prelocking());
/*
NOTE: We don't want to ignore set of locked tables here if we are
under explicit LOCK TABLES since it will open gap for deadlock
too wide (and also is not backward compatible).
*/
if (! (table= open_table(thd, create_table, thd->mem_root, (bool*) 0,
(MYSQL_LOCK_IGNORE_FLUSH |
((thd->prelocked_mode == PRELOCKED) ?
MYSQL_OPEN_IGNORE_LOCKED_TABLES:0)))))
quick_rm_table(create_info->db_type, create_table->db,
table_case_name(create_info, create_table->table_name));
if (create_info->table_existed &&
!(create_info->options & HA_LEX_CREATE_TMP_TABLE))
{
/*
This means that someone created table underneath server
or it was created via different mysqld front-end to the
cluster. We don't have much options but throw an error.
*/
my_error(ER_TABLE_EXISTS_ERROR, MYF(0), create_table->table_name);
DBUG_RETURN(0);
}
DBUG_EXECUTE_IF("sleep_create_select_before_open", my_sleep(6000000););
if (!(create_info->options & HA_LEX_CREATE_TMP_TABLE))
{
VOID(pthread_mutex_lock(&LOCK_open));
if (reopen_name_locked_table(thd, create_table, FALSE))
{
quick_rm_table(create_info->db_type, create_table->db,
table_case_name(create_info,
create_table->table_name));
}
else
table= create_table->table;
VOID(pthread_mutex_unlock(&LOCK_open));
}
else
{
if (!(table= open_table(thd, create_table, thd->mem_root, (bool*) 0,
MYSQL_OPEN_TEMPORARY_ONLY)) &&
!create_info->table_existed)
{
/*
This shouldn't happen as creation of temporary table should make
it preparable for open. But let us do close_temporary_table() here
just in case.
*/
close_temporary_table(thd, create_table->db, create_table->table_name);
}
}
}
reenable_binlog(thd);
if (!table) // open failed
DBUG_RETURN(0);
}
/*
FIXME: What happens if trigger manages to be created while we are
obtaining this lock ? May be it is sensible just to disable
trigger execution in this case ? Or will MYSQL_LOCK_IGNORE_FLUSH
save us from that ?
*/
DBUG_EXECUTE_IF("sleep_create_select_before_lock", my_sleep(6000000););
table->reginfo.lock_type=TL_WRITE;
if (! ((*lock)= mysql_lock_tables(thd, &table, 1,
MYSQL_LOCK_IGNORE_FLUSH, &not_used)))
{
VOID(pthread_mutex_lock(&LOCK_open));
hash_delete(&open_cache,(byte*) table);
VOID(pthread_mutex_unlock(&LOCK_open));
quick_rm_table(create_info->db_type, create_table->db,
table_case_name(create_info, create_table->table_name));
if (!create_info->table_existed)
drop_open_table(thd, table, create_table->db, create_table->table_name);
DBUG_RETURN(0);
}
table->file->extra(HA_EXTRA_WRITE_CACHE);
DBUG_RETURN(table);
}
......@@ -3059,8 +3102,10 @@ select_create::prepare(List<Item> &values, SELECT_LEX_UNIT *u)
(thd->variables.sql_mode &
(MODE_STRICT_TRANS_TABLES |
MODE_STRICT_ALL_TABLES)));
DBUG_RETURN(check_that_all_fields_are_given_values(thd, table,
table_list));
if (check_that_all_fields_are_given_values(thd, table, table_list))
DBUG_RETURN(1);
table->file->extra(HA_EXTRA_WRITE_CACHE);
DBUG_RETURN(0);
}
......@@ -3092,31 +3137,18 @@ bool select_create::send_eof()
{
table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY);
table->file->extra(HA_EXTRA_WRITE_CANNOT_REPLACE);
VOID(pthread_mutex_lock(&LOCK_open));
mysql_unlock_tables(thd, lock);
/*
TODO:
Check if we can remove the following two rows.
We should be able to just keep the table in the table cache.
*/
if (!table->s->tmp_table)
if (lock)
{
ulong version= table->s->version;
hash_delete(&open_cache,(byte*) table);
/* Tell threads waiting for refresh that something has happened */
if (version != refresh_version)
broadcast_refresh();
mysql_unlock_tables(thd, lock);
lock= 0;
}
lock=0;
table=0;
VOID(pthread_mutex_unlock(&LOCK_open));
}
return tmp;
}
void select_create::abort()
{
VOID(pthread_mutex_lock(&LOCK_open));
if (lock)
{
mysql_unlock_tables(thd, lock);
......@@ -3126,22 +3158,10 @@ void select_create::abort()
{
table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY);
table->file->extra(HA_EXTRA_WRITE_CANNOT_REPLACE);
enum db_type table_type=table->s->db_type;
if (!table->s->tmp_table)
{
ulong version= table->s->version;
hash_delete(&open_cache,(byte*) table);
if (!create_info->table_existed)
quick_rm_table(table_type, create_table->db, create_table->table_name);
/* Tell threads waiting for refresh that something has happened */
if (version != refresh_version)
broadcast_refresh();
}
else if (!create_info->table_existed)
close_temporary_table(thd, create_table->db, create_table->table_name);
if (!create_info->table_existed)
drop_open_table(thd, table, create_table->db, create_table->table_name);
table=0;
}
VOID(pthread_mutex_unlock(&LOCK_open));
}
......
sql/sql_parse.cc
View file @ d5dbdd98
......@@ -3014,7 +3014,13 @@ mysql_execute_command(THD *thd)
select_lex->options|= SELECT_NO_UNLOCK;
unit->set_limit(select_lex);
if (!(res= open_and_lock_tables(thd, select_tables)))
if (!(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE))
{
lex->link_first_table_back(create_table, link_to_local);
create_table->create= TRUE;
}
if (!(res= open_and_lock_tables(thd, lex->query_tables)))
{
/*
Is table which we are changing used somewhere in other parts
......@@ -3023,6 +3029,7 @@ mysql_execute_command(THD *thd)
if (!(create_info.options & HA_LEX_CREATE_TMP_TABLE))
{
TABLE_LIST *duplicate;
create_table= lex->unlink_first_table(&link_to_local);
if ((duplicate= unique_table(thd, create_table, select_tables, 0)))
{
update_non_unique_table_error(create_table, "CREATE", duplicate);
......@@ -3066,6 +3073,9 @@ mysql_execute_command(THD *thd)
delete sel_result;
}
}
else if (!(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE))
create_table= lex->unlink_first_table(&link_to_local);
}
else
{
......
sql/sql_prepare.cc
View file @ d5dbdd98
......@@ -1491,8 +1491,21 @@ static bool mysql_test_create_table(Prepared_statement *stmt)
if (select_lex->item_list.elements)
{
if (!(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE))
{
lex->link_first_table_back(create_table, link_to_local);
create_table->create= TRUE;
}
if (open_and_lock_tables(stmt->thd, lex->query_tables))
DBUG_RETURN(TRUE);
if (!(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE))
create_table= lex->unlink_first_table(&link_to_local);
select_lex->context.resolve_in_select_list= TRUE;
res= select_like_stmt_test_with_open_n_lock(stmt, tables, 0, 0);
res= select_like_stmt_test(stmt, 0, 0);
}
/* put tables back for PS rexecuting */
......
sql/sql_table.cc
View file @ d5dbdd98
......@@ -62,8 +62,8 @@ static void set_tmp_file_path(char *buf, size_t bufsize, THD *thd);
# Size of path
*/
static uint build_table_path(char *buff, size_t bufflen, const char *db,
const char *table, const char *ext)
uint build_table_path(char *buff, size_t bufflen, const char *db,
const char *table, const char *ext)
{
strxnmov(buff, bufflen-1, mysql_data_home, "/", db, "/", table, ext,
NullS);
......@@ -1722,7 +1722,14 @@ bool mysql_create_table(THD *thd,const char *db, const char *table_name,
VOID(pthread_mutex_lock(&LOCK_open));
if (!internal_tmp_table && !(create_info->options & HA_LEX_CREATE_TMP_TABLE))
{
if (!access(path,F_OK))
/*
Inspecting table cache for placeholders created by concurrent
CREATE TABLE ... SELECT statements to avoid interfering with them
is 5.0-only solution. Starting from 5.1 we solve this problem by
obtaining name-lock on the table to be created first.
*/
if (table_cache_has_open_placeholder(thd, db, table_name) ||
!access(path, F_OK))
{
if (create_info->options & HA_LEX_CREATE_IF_NOT_EXISTS)
goto warn;
......@@ -2051,7 +2058,7 @@ static int prepare_for_restore(THD* thd, TABLE_LIST* table,
to finish the restore in the handler later on
*/
pthread_mutex_lock(&LOCK_open);
if (reopen_name_locked_table(thd, table))
if (reopen_name_locked_table(thd, table, TRUE))
{
unlock_table_name(thd, table);
pthread_mutex_unlock(&LOCK_open);
......@@ -2158,7 +2165,7 @@ static int prepare_for_repair(THD* thd, TABLE_LIST *table_list,
to finish the repair in the handler later on.
*/
pthread_mutex_lock(&LOCK_open);
if (reopen_name_locked_table(thd, table_list))
if (reopen_name_locked_table(thd, table_list, TRUE))
{
unlock_table_name(thd, table_list);
pthread_mutex_unlock(&LOCK_open);
......@@ -2803,10 +2810,24 @@ bool mysql_create_like_table(THD* thd, TABLE_LIST* table,
}
else
{
bool exists;
strxmov(dst_path, mysql_data_home, "/", db, "/", table_name,
reg_ext, NullS);
fn_format(dst_path, dst_path, "", "", MYF(MY_UNPACK_FILENAME));
if (!access(dst_path, F_OK))
/*
Note that this critical section should actually cover most
of mysql_create_like_table() function. See bugs #18950 and
#23667 for more information.
Also note that starting from 5.1 we obtain name-lock on
target table instead of inspecting table cache for presence
of open placeholders (see comment in mysql_create_table()).
*/
pthread_mutex_lock(&LOCK_open);
exists= (table_cache_has_open_placeholder(thd, db, table_name) ||
!access(dst_path, F_OK));
pthread_mutex_unlock(&LOCK_open);
if (exists)
goto table_exists;
}
......@@ -3160,9 +3181,14 @@ view_err:
else
{
char dir_buff[FN_REFLEN];
bool exists;
strxnmov(dir_buff, FN_REFLEN, mysql_real_data_home, new_db, NullS);
if (!access(fn_format(new_name_buff,new_name_buff,dir_buff,reg_ext,0),
F_OK))
VOID(pthread_mutex_lock(&LOCK_open));
exists= (table_cache_has_open_placeholder(thd, new_db, new_name) ||
!access(fn_format(new_name_buff, new_name_buff, dir_buff,
reg_ext, 0), F_OK));
VOID(pthread_mutex_unlock(&LOCK_open));
if (exists)
{
/* Table will be closed in do_command() */
my_error(ER_TABLE_EXISTS_ERROR, MYF(0), new_alias);
......@@ -3247,8 +3273,22 @@ view_err:
if (!error && (new_name != table_name || new_db != db))
{
thd->proc_info="rename";
/* Then do a 'simple' rename of the table */
if (!access(new_name_buff,F_OK))
/*
Then do a 'simple' rename of the table. First we need to close all
instances of 'source' table.
*/
close_cached_table(thd, table);
/*
Then, we want check once again that target table does not exist.
Note that we can't fully rely on results of previous check since
no lock was taken on target table during it. We also can't do this
before calling close_cached_table() as the latter temporarily
releases LOCK_open mutex.
Also note that starting from 5.1 we use approach with obtaining
of name-lock on target table.
*/
if (table_cache_has_open_placeholder(thd, new_db, new_name) ||
!access(new_name_buff,F_OK))
{
my_error(ER_TABLE_EXISTS_ERROR, MYF(0), new_name);
error= -1;
......@@ -3256,7 +3296,6 @@ view_err:
else
{
*fn_ext(new_name)=0;
close_cached_table(thd, table);
if (mysql_rename_table(old_db_type,db,table_name,new_db,new_alias))
error= -1;
else if (Table_triggers_list::change_table_name(thd, db, table_name,
......@@ -3806,17 +3845,6 @@ view_err:
current_pid, thd->thread_id);
if (lower_case_table_names)
my_casedn_str(files_charset_info, old_name);
if (new_name != table_name || new_db != db)
{
if (!access(new_name_buff,F_OK))
{
error=1;
my_error(ER_TABLE_EXISTS_ERROR, MYF(0), new_name_buff);
VOID(quick_rm_table(new_db_type,new_db,tmp_name));
VOID(pthread_mutex_unlock(&LOCK_open));
goto err;
}
}
#if (!defined( __WIN__) && !defined( __EMX__) && !defined( OS2))
if (table->file->has_transactions())
......@@ -3835,6 +3863,22 @@ view_err:
table->file->extra(HA_EXTRA_FORCE_REOPEN); // Don't use this file anymore
#endif
if (new_name != table_name || new_db != db)
{
/*
Check that there is no table with target name. See the
comment describing code for 'simple' ALTER TABLE ... RENAME.
*/
if (table_cache_has_open_placeholder(thd, new_db, new_name) ||
!access(new_name_buff,F_OK))
{
error=1;
my_error(ER_TABLE_EXISTS_ERROR, MYF(0), new_name_buff);
VOID(quick_rm_table(new_db_type,new_db,tmp_name));
VOID(pthread_mutex_unlock(&LOCK_open));
goto err;
}
}
error=0;
if (!need_copy_table)
......
sql/sql_trigger.cc
View file @ d5dbdd98
......@@ -271,7 +271,7 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create)
/* We also don't allow creation of triggers on views. */
tables->required_type= FRMTYPE_TABLE;
if (reopen_name_locked_table(thd, tables))
if (reopen_name_locked_table(thd, tables, TRUE))
{
unlock_table_name(thd, tables);
goto end;
......
sql/sql_yacc.yy
View file @ d5dbdd98
......@@ -1474,9 +1474,7 @@ create:
lex->sql_command= SQLCOM_CREATE_TABLE;
if (!lex->select_lex.add_table_to_list(thd, $5, NULL,
TL_OPTION_UPDATING,
(using_update_log ?
TL_READ_NO_INSERT:
TL_READ)))
TL_WRITE))
MYSQL_YYABORT;
lex->alter_info.reset();
lex->col_list.empty();
......
sql/table.h
View file @ d5dbdd98
......@@ -188,6 +188,8 @@ typedef struct st_table_share
} TABLE_SHARE;
extern ulong refresh_version;
/* Information for one open table */
struct st_table {
......@@ -268,7 +270,24 @@ struct st_table {
my_bool force_index;
my_bool distinct,const_table,no_rows;
my_bool key_read, no_keyread;
my_bool locked_by_flush;
/*
Placeholder for an open table which prevents other connections
from taking name-locks on this table. Typically used with
TABLE_SHARE::version member to take an exclusive name-lock on
this table name -- a name lock that not only prevents other
threads from opening the table, but also blocks other name
locks. This is achieved by:
- setting open_placeholder to 1 - this will block other name
locks, as wait_for_locked_table_name will be forced to wait,
see table_is_used for details.
- setting version to 0 - this will force other threads to close
the instance of this table and wait (this is the same approach
as used for usual name locks).
An exclusively name-locked table currently can have no handler
object associated with it (db_stat is always 0), but please do
not rely on that.
*/
my_bool open_placeholder;
my_bool locked_by_name;
my_bool fulltext_searched;
my_bool no_cache;
......@@ -291,6 +310,13 @@ struct st_table {
bool fill_item_list(List<Item> *item_list) const;
void reset_item_list(List<Item> *item_list) const;
/* Is table open or should be treated as such by name-locking? */
inline bool is_name_opened() { return db_stat || open_placeholder; }
/*
Is this instance of the table should be reopen or represents a name-lock?
*/
inline bool needs_reopen_or_name_lock()
{ return s->version != refresh_version; }
};
enum enum_schema_table_state
......@@ -648,6 +674,12 @@ typedef struct st_table_list
used for implicit LOCK TABLES only and won't be used in real statement.
*/
bool prelocking_placeholder;
/*
This TABLE_LIST object corresponds to the table to be created
so it is possible that it does not exist (used in CREATE TABLE
... SELECT implementation).
*/
bool create;
enum enum_schema_table_state schema_table_state;
void calc_md5(char *buffer);
......@@ -655,7 +687,11 @@ typedef struct st_table_list
int view_check_option(THD *thd, bool ignore_failure);
bool setup_underlying(THD *thd);
void cleanup_items();
bool placeholder() {return derived || view || schema_table || !table; }
bool placeholder()
{
return derived || view || schema_table || create && !table->db_stat ||
!table;
}
void print(THD *thd, String *str);
bool check_single_table(st_table_list **table, table_map map,
st_table_list *view);
......
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