diff options
Diffstat (limited to 'sql/sql_handler.cc')
| -rw-r--r-- | sql/sql_handler.cc | 68 |
1 files changed, 56 insertions, 12 deletions
diff --git a/sql/sql_handler.cc b/sql/sql_handler.cc index 9aefa71647e..822f2b2c419 100644 --- a/sql/sql_handler.cc +++ b/sql/sql_handler.cc @@ -65,11 +65,6 @@ static enum enum_ha_read_modes rkey_to_rnext[]= { RNEXT_SAME, RNEXT, RPREV, RNEXT, RPREV, RNEXT, RPREV, RPREV }; -#define HANDLER_TABLES_HACK(thd) { \ - TABLE *tmp=thd->open_tables; \ - thd->open_tables=thd->handler_tables; \ - thd->handler_tables=tmp; } - static int mysql_ha_flush_table(THD *thd, TABLE **table_ptr, uint mode_flags); @@ -187,6 +182,7 @@ bool mysql_ha_open(THD *thd, TABLE_LIST *tables, bool reopen) char *db, *name, *alias; uint dblen, namelen, aliaslen, counter; int error; + TABLE *backup_open_tables; DBUG_ENTER("mysql_ha_open"); DBUG_PRINT("enter",("'%s'.'%s' as '%s' reopen: %d", tables->db, tables->table_name, tables->alias, @@ -216,17 +212,39 @@ bool mysql_ha_open(THD *thd, TABLE_LIST *tables, bool reopen) } /* + Save and reset the open_tables list so that open_tables() won't + be able to access (or know about) the previous list. And on return + from open_tables(), thd->open_tables will contain only the opened + table. + + The thd->handler_tables list is kept as-is to avoid deadlocks if + open_table(), called by open_tables(), needs to back-off because + of a pending name-lock on the table being opened. + + See open_table() back-off comments for more details. + */ + backup_open_tables= thd->open_tables; + thd->open_tables= NULL; + + /* open_tables() will set 'tables->table' if successful. It must be NULL for a real open when calling open_tables(). */ DBUG_ASSERT(! tables->table); - HANDLER_TABLES_HACK(thd); /* for now HANDLER can be used only for real TABLES */ tables->required_type= FRMTYPE_TABLE; error= open_tables(thd, &tables, &counter, 0); - HANDLER_TABLES_HACK(thd); + /* restore the state and merge the opened table into handler_tables list */ + if (thd->open_tables) + { + thd->open_tables->next= thd->handler_tables; + thd->handler_tables= thd->open_tables; + } + + thd->open_tables= backup_open_tables; + if (error) goto err; @@ -351,7 +369,7 @@ bool mysql_ha_read(THD *thd, TABLE_LIST *tables, ha_rows select_limit_cnt, ha_rows offset_limit_cnt) { TABLE_LIST *hash_tables; - TABLE *table; + TABLE *table, *backup_open_tables; MYSQL_LOCK *lock; List<Item> list; Protocol *protocol= thd->protocol; @@ -361,7 +379,7 @@ bool mysql_ha_read(THD *thd, TABLE_LIST *tables, uint num_rows; byte *key; uint key_len; - bool not_used; + bool need_reopen; DBUG_ENTER("mysql_ha_read"); DBUG_PRINT("enter",("'%s'.'%s' as '%s'", tables->db, tables->table_name, tables->alias)); @@ -375,6 +393,7 @@ bool mysql_ha_read(THD *thd, TABLE_LIST *tables, List_iterator<Item> it(list); it++; +retry: if ((hash_tables= (TABLE_LIST*) hash_search(&thd->handler_tables_hash, (byte*) tables->alias, strlen(tables->alias) + 1))) @@ -427,9 +446,34 @@ bool mysql_ha_read(THD *thd, TABLE_LIST *tables, } tables->table=table; - HANDLER_TABLES_HACK(thd); - lock= mysql_lock_tables(thd, &tables->table, 1, 0, ¬_used); - HANDLER_TABLES_HACK(thd); + /* save open_tables state */ + backup_open_tables= thd->open_tables; + /* + mysql_lock_tables() needs thd->open_tables to be set correctly to + be able to handle aborts properly. When the abort happens, it's + safe to not protect thd->handler_tables because it won't close any + tables. + */ + thd->open_tables= thd->handler_tables; + + lock= mysql_lock_tables(thd, &tables->table, 1, + MYSQL_LOCK_NOTIFY_IF_NEED_REOPEN, &need_reopen); + + /* restore previous context */ + thd->open_tables= backup_open_tables; + + if (need_reopen) + { + mysql_ha_close_table(thd, tables); + hash_tables->table= NULL; + /* + The lock might have been aborted, we need to manually reset + thd->some_tables_deleted because handler's tables are closed + in a non-standard way. Otherwise we might loop indefinitely. + */ + thd->some_tables_deleted= 0; + goto retry; + } if (!lock) goto err0; // mysql_lock_tables() printed error message already |