diff options
Diffstat (limited to 'sql/sql_class.h')
| -rw-r--r-- | sql/sql_class.h | 199 |
1 files changed, 31 insertions, 168 deletions
diff --git a/sql/sql_class.h b/sql/sql_class.h index 25b136bc4ca..c11c15571f2 100644 --- a/sql/sql_class.h +++ b/sql/sql_class.h @@ -1006,7 +1006,6 @@ public: of the main statement is called. */ enum enum_locked_tables_mode locked_tables_mode; - ulong version; uint current_tablenr; enum enum_flags { @@ -1025,15 +1024,6 @@ public: */ Open_tables_state() : state_flags(0U) { } - /** - Prepare Open_tables_state instance for operations dealing with tables. - */ - void init_open_tables_state(THD *thd, ulong version_arg) - { - reset_open_tables_state(thd); - version= version_arg; - } - void set_open_tables_state(Open_tables_state *state) { *this= *state; @@ -1229,162 +1219,6 @@ private: /** - An abstract class for a strategy specifying how the prelocking - algorithm should extend the prelocking set while processing - already existing elements in the set. -*/ - -class Prelocking_strategy -{ -public: - virtual ~Prelocking_strategy() { } - - virtual bool handle_routine(THD *thd, Query_tables_list *prelocking_ctx, - Sroutine_hash_entry *rt, sp_head *sp, - bool *need_prelocking) = 0; - virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx, - TABLE_LIST *table_list, bool *need_prelocking) = 0; - virtual bool handle_view(THD *thd, Query_tables_list *prelocking_ctx, - TABLE_LIST *table_list, bool *need_prelocking)= 0; -}; - - -/** - A Strategy for prelocking algorithm suitable for DML statements. - - Ensures that all tables used by all statement's SF/SP/triggers and - required for foreign key checks are prelocked and SF/SPs used are - cached. -*/ - -class DML_prelocking_strategy : public Prelocking_strategy -{ -public: - virtual bool handle_routine(THD *thd, Query_tables_list *prelocking_ctx, - Sroutine_hash_entry *rt, sp_head *sp, - bool *need_prelocking); - virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx, - TABLE_LIST *table_list, bool *need_prelocking); - virtual bool handle_view(THD *thd, Query_tables_list *prelocking_ctx, - TABLE_LIST *table_list, bool *need_prelocking); -}; - - -/** - A strategy for prelocking algorithm to be used for LOCK TABLES - statement. -*/ - -class Lock_tables_prelocking_strategy : public DML_prelocking_strategy -{ - virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx, - TABLE_LIST *table_list, bool *need_prelocking); -}; - - -/** - Strategy for prelocking algorithm to be used for ALTER TABLE statements. - - Unlike DML or LOCK TABLES strategy, it doesn't - prelock triggers, views or stored routines, since they are not - used during ALTER. -*/ - -class Alter_table_prelocking_strategy : public Prelocking_strategy -{ -public: - - Alter_table_prelocking_strategy(Alter_info *alter_info) - : m_alter_info(alter_info) - {} - - virtual bool handle_routine(THD *thd, Query_tables_list *prelocking_ctx, - Sroutine_hash_entry *rt, sp_head *sp, - bool *need_prelocking); - virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx, - TABLE_LIST *table_list, bool *need_prelocking); - virtual bool handle_view(THD *thd, Query_tables_list *prelocking_ctx, - TABLE_LIST *table_list, bool *need_prelocking); - -private: - Alter_info *m_alter_info; -}; - - -/** - A context of open_tables() function, used to recover - from a failed open_table() or open_routine() attempt. - - Implemented in sql_base.cc. -*/ - -class Open_table_context -{ -public: - enum enum_open_table_action - { - OT_NO_ACTION= 0, - OT_WAIT_MDL_LOCK, - OT_WAIT_TDC, - OT_DISCOVER, - OT_REPAIR - }; - Open_table_context(THD *thd, ulong timeout); - - bool recover_from_failed_open(THD *thd, MDL_request *mdl_request, - TABLE_LIST *table); - bool request_backoff_action(enum_open_table_action action_arg); - - void add_request(MDL_request *request) - { m_mdl_requests.push_front(request); } - - bool can_recover_from_failed_open() const - { return m_action != OT_NO_ACTION; } - - /** - When doing a back-off, we close all tables acquired by this - statement. Return an MDL savepoint taken at the beginning of - the statement, so that we can rollback to it before waiting on - locks. - */ - MDL_ticket *start_of_statement_svp() const - { - return m_start_of_statement_svp; - } - - MDL_request *get_global_mdl_request(THD *thd); - - inline ulong get_timeout() const - { - return m_timeout; - } - -private: - /** List of requests for all locks taken so far. Used for waiting on locks. */ - MDL_request_list m_mdl_requests; - /** Back off action. */ - enum enum_open_table_action m_action; - MDL_ticket *m_start_of_statement_svp; - /** - Whether we had any locks when this context was created. - If we did, they are from the previous statement of a transaction, - and we can't safely do back-off (and release them). - */ - bool m_has_locks; - /** - Request object for global intention exclusive lock which is acquired during - opening tables for statements which take upgradable shared metadata locks. - */ - MDL_request *m_global_mdl_request; - /** - Lock timeout in seconds. Initialized to LONG_TIMEOUT when opening system - tables or to the "lock_wait_timeout" system variable for regular tables. - */ - uint m_timeout; -}; - - -/** Tables that were locked with LOCK TABLES statement. Encapsulates a list of TABLE_LIST instances for tables @@ -2097,8 +1931,31 @@ public: uint server_status,open_options; enum enum_thread_type system_thread; uint select_number; //number of select (used for EXPLAIN) - /* variables.transaction_isolation is reset to this after each commit */ - enum_tx_isolation session_tx_isolation; + /* + Current or next transaction isolation level. + When a connection is established, the value is taken from + @@session.tx_isolation (default transaction isolation for + the session), which is in turn taken from @@global.tx_isolation + (the global value). + If there is no transaction started, this variable + holds the value of the next transaction's isolation level. + When a transaction starts, the value stored in this variable + becomes "actual". + At transaction commit or rollback, we assign this variable + again from @@session.tx_isolation. + The only statement that can otherwise change the value + of this variable is SET TRANSACTION ISOLATION LEVEL. + Its purpose is to effect the isolation level of the next + transaction in this session. When this statement is executed, + the value in this variable is changed. However, since + this statement is only allowed when there is no active + transaction, this assignment (naturally) only affects the + upcoming transaction. + At the end of the current active transaction the value is + be reset again from @@session.tx_isolation, as described + above. + */ + enum_tx_isolation tx_isolation; enum_check_fields count_cuted_fields; DYNAMIC_ARRAY user_var_events; /* For user variables replication */ @@ -2843,6 +2700,12 @@ public: void set_query_and_id(char *query_arg, uint32 query_length_arg, query_id_t new_query_id); void set_query_id(query_id_t new_query_id); + void set_open_tables(TABLE *open_tables_arg) + { + mysql_mutex_lock(&LOCK_thd_data); + open_tables= open_tables_arg; + mysql_mutex_unlock(&LOCK_thd_data); + } void enter_locked_tables_mode(enum_locked_tables_mode mode_arg) { DBUG_ASSERT(locked_tables_mode == LTM_NONE); |