/***************************************************************************** Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA *****************************************************************************/ /**************************************************//** @file include/lock0lock.h The transaction lock system Created 5/7/1996 Heikki Tuuri *******************************************************/ #ifndef lock0lock_h #define lock0lock_h #include "univ.i" #include "buf0types.h" #include "trx0types.h" #include "mtr0types.h" #include "rem0types.h" #include "dict0types.h" #include "que0types.h" #include "lock0types.h" #include "hash0hash.h" #include "srv0srv.h" #include "ut0vec.h" #include "gis0rtree.h" #include "lock0prdt.h" /** Alternatives for innodb_lock_schedule_algorithm, which can be changed by setting innodb_lock_schedule_algorithm. */ enum innodb_lock_schedule_algorithm_t { /*!< First Come First Served */ INNODB_LOCK_SCHEDULE_ALGORITHM_FCFS, /*!< Variance-Aware-Transaction-Scheduling */ INNODB_LOCK_SCHEDULE_ALGORITHM_VATS }; extern ulong innodb_lock_schedule_algorithm; // Forward declaration class ReadView; /*********************************************************************//** Gets the size of a lock struct. @return size in bytes */ ulint lock_get_size(void); /*===============*/ /*********************************************************************//** Creates the lock system at database start. */ void lock_sys_create( /*============*/ ulint n_cells); /*!< in: number of slots in lock hash table */ /** Resize the lock hash table. @param[in] n_cells number of slots in lock hash table */ void lock_sys_resize( ulint n_cells); /*********************************************************************//** Closes the lock system at database shutdown. */ void lock_sys_close(void); /*================*/ /*********************************************************************//** Gets the heap_no of the smallest user record on a page. @return heap_no of smallest user record, or PAGE_HEAP_NO_SUPREMUM */ UNIV_INLINE ulint lock_get_min_heap_no( /*=================*/ const buf_block_t* block); /*!< in: buffer block */ /*************************************************************//** Updates the lock table when we have reorganized a page. NOTE: we copy also the locks set on the infimum of the page; the infimum may carry locks if an update of a record is occurring on the page, and its locks were temporarily stored on the infimum. */ void lock_move_reorganize_page( /*======================*/ const buf_block_t* block, /*!< in: old index page, now reorganized */ const buf_block_t* oblock);/*!< in: copy of the old, not reorganized page */ /*************************************************************//** Moves the explicit locks on user records to another page if a record list end is moved to another page. */ void lock_move_rec_list_end( /*===================*/ const buf_block_t* new_block, /*!< in: index page to move to */ const buf_block_t* block, /*!< in: index page */ const rec_t* rec); /*!< in: record on page: this is the first record moved */ /*************************************************************//** Moves the explicit locks on user records to another page if a record list start is moved to another page. */ void lock_move_rec_list_start( /*=====================*/ const buf_block_t* new_block, /*!< in: index page to move to */ const buf_block_t* block, /*!< in: index page */ const rec_t* rec, /*!< in: record on page: this is the first record NOT copied */ const rec_t* old_end); /*!< in: old previous-to-last record on new_page before the records were copied */ /*************************************************************//** Updates the lock table when a page is split to the right. */ void lock_update_split_right( /*====================*/ const buf_block_t* right_block, /*!< in: right page */ const buf_block_t* left_block); /*!< in: left page */ /*************************************************************//** Updates the lock table when a page is merged to the right. */ void lock_update_merge_right( /*====================*/ const buf_block_t* right_block, /*!< in: right page to which merged */ const rec_t* orig_succ, /*!< in: original successor of infimum on the right page before merge */ const buf_block_t* left_block); /*!< in: merged index page which will be discarded */ /*************************************************************//** Updates the lock table when the root page is copied to another in btr_root_raise_and_insert. Note that we leave lock structs on the root page, even though they do not make sense on other than leaf pages: the reason is that in a pessimistic update the infimum record of the root page will act as a dummy carrier of the locks of the record to be updated. */ void lock_update_root_raise( /*===================*/ const buf_block_t* block, /*!< in: index page to which copied */ const buf_block_t* root); /*!< in: root page */ /*************************************************************//** Updates the lock table when a page is copied to another and the original page is removed from the chain of leaf pages, except if page is the root! */ void lock_update_copy_and_discard( /*=========================*/ const buf_block_t* new_block, /*!< in: index page to which copied */ const buf_block_t* block); /*!< in: index page; NOT the root! */ /*************************************************************//** Updates the lock table when a page is split to the left. */ void lock_update_split_left( /*===================*/ const buf_block_t* right_block, /*!< in: right page */ const buf_block_t* left_block); /*!< in: left page */ /*************************************************************//** Updates the lock table when a page is merged to the left. */ void lock_update_merge_left( /*===================*/ const buf_block_t* left_block, /*!< in: left page to which merged */ const rec_t* orig_pred, /*!< in: original predecessor of supremum on the left page before merge */ const buf_block_t* right_block); /*!< in: merged index page which will be discarded */ /*************************************************************//** Updates the lock table when a page is splited and merged to two pages. */ UNIV_INTERN void lock_update_split_and_merge( const buf_block_t* left_block, /*!< in: left page to which merged */ const rec_t* orig_pred, /*!< in: original predecessor of supremum on the left page before merge*/ const buf_block_t* right_block);/*!< in: right page from which merged */ /*************************************************************//** Resets the original locks on heir and replaces them with gap type locks inherited from rec. */ void lock_rec_reset_and_inherit_gap_locks( /*=================================*/ const buf_block_t* heir_block, /*!< in: block containing the record which inherits */ const buf_block_t* block, /*!< in: block containing the record from which inherited; does NOT reset the locks on this record */ ulint heir_heap_no, /*!< in: heap_no of the inheriting record */ ulint heap_no); /*!< in: heap_no of the donating record */ /*************************************************************//** Updates the lock table when a page is discarded. */ void lock_update_discard( /*================*/ const buf_block_t* heir_block, /*!< in: index page which will inherit the locks */ ulint heir_heap_no, /*!< in: heap_no of the record which will inherit the locks */ const buf_block_t* block); /*!< in: index page which will be discarded */ /*************************************************************//** Updates the lock table when a new user record is inserted. */ void lock_update_insert( /*===============*/ const buf_block_t* block, /*!< in: buffer block containing rec */ const rec_t* rec); /*!< in: the inserted record */ /*************************************************************//** Updates the lock table when a record is removed. */ void lock_update_delete( /*===============*/ const buf_block_t* block, /*!< in: buffer block containing rec */ const rec_t* rec); /*!< in: the record to be removed */ /*********************************************************************//** Stores on the page infimum record the explicit locks of another record. This function is used to store the lock state of a record when it is updated and the size of the record changes in the update. The record is in such an update moved, perhaps to another page. The infimum record acts as a dummy carrier record, taking care of lock releases while the actual record is being moved. */ void lock_rec_store_on_page_infimum( /*===========================*/ const buf_block_t* block, /*!< in: buffer block containing rec */ const rec_t* rec); /*!< in: record whose lock state is stored on the infimum record of the same page; lock bits are reset on the record */ /*********************************************************************//** Restores the state of explicit lock requests on a single record, where the state was stored on the infimum of the page. */ void lock_rec_restore_from_page_infimum( /*===============================*/ const buf_block_t* block, /*!< in: buffer block containing rec */ const rec_t* rec, /*!< in: record whose lock state is restored */ const buf_block_t* donator);/*!< in: page (rec is not necessarily on this page) whose infimum stored the lock state; lock bits are reset on the infimum */ /*********************************************************************//** Determines if there are explicit record locks on a page. @return an explicit record lock on the page, or NULL if there are none */ lock_t* lock_rec_expl_exist_on_page( /*========================*/ ulint space, /*!< in: space id */ ulint page_no)/*!< in: page number */ MY_ATTRIBUTE((warn_unused_result)); /*********************************************************************//** Checks if locks of other transactions prevent an immediate insert of a record. If they do, first tests if the query thread should anyway be suspended for some reason; if not, then puts the transaction and the query thread to the lock wait state and inserts a waiting request for a gap x-lock to the lock queue. @return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */ dberr_t lock_rec_insert_check_and_lock( /*===========================*/ ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG bit is set, does nothing */ const rec_t* rec, /*!< in: record after which to insert */ buf_block_t* block, /*!< in/out: buffer block of rec */ dict_index_t* index, /*!< in: index */ que_thr_t* thr, /*!< in: query thread */ mtr_t* mtr, /*!< in/out: mini-transaction */ ibool* inherit)/*!< out: set to TRUE if the new inserted record maybe should inherit LOCK_GAP type locks from the successor record */ MY_ATTRIBUTE((warn_unused_result)); /*********************************************************************//** Enqueues a waiting request for a lock which cannot be granted immediately. Checks for deadlocks. @return DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED, or DB_SUCCESS_LOCKED_REC; DB_SUCCESS_LOCKED_REC means that there was a deadlock, but another transaction was chosen as a victim, and we got the lock immediately: no need to wait then */ dberr_t lock_rec_enqueue_waiting( /*=====================*/ ulint type_mode,/*!< in: lock mode this transaction is requesting: LOCK_S or LOCK_X, possibly ORed with LOCK_GAP or LOCK_REC_NOT_GAP, ORed with LOCK_INSERT_INTENTION if this waiting lock request is set when performing an insert of an index record */ const buf_block_t* block, /*!< in: buffer block containing the record */ ulint heap_no,/*!< in: heap number of the record */ dict_index_t* index, /*!< in: index of record */ que_thr_t* thr, /*!< in: query thread */ lock_prdt_t* prdt); /*!< in: Minimum Bounding Box */ /*************************************************************//** Removes a record lock request, waiting or granted, from the queue and grants locks to other transactions in the queue if they now are entitled to a lock. NOTE: all record locks contained in in_lock are removed. */ void lock_rec_dequeue_from_page( /*=======================*/ lock_t* in_lock); /*!< in: record lock object: all record locks which are contained in this lock object are removed; transactions waiting behind will get their lock requests granted, if they are now qualified to it */ /*************************************************************//** Moves the locks of a record to another record and resets the lock bits of the donating record. */ UNIV_INLINE void lock_rec_move( /*==========*/ const buf_block_t* receiver, /*!< in: buffer block containing the receiving record */ const buf_block_t* donator, /*!< in: buffer block containing the donating record */ ulint receiver_heap_no,/*!< in: heap_no of the record which gets the locks; there must be no lock requests on it! */ ulint donator_heap_no);/*!< in: heap_no of the record which gives the locks */ /*************************************************************//** Moves the locks of a record to another record and resets the lock bits of the donating record. */ void lock_rec_move_low( /*==============*/ hash_table_t* lock_hash, /*!< in: hash table to use */ const buf_block_t* receiver, /*!< in: buffer block containing the receiving record */ const buf_block_t* donator, /*!< in: buffer block containing the donating record */ ulint receiver_heap_no,/*!< in: heap_no of the record which gets the locks; there must be no lock requests on it! */ ulint donator_heap_no);/*!< in: heap_no of the record which gives the locks */ /*********************************************************************//** Checks if locks of other transactions prevent an immediate modify (update, delete mark, or delete unmark) of a clustered index record. If they do, first tests if the query thread should anyway be suspended for some reason; if not, then puts the transaction and the query thread to the lock wait state and inserts a waiting request for a record x-lock to the lock queue. @return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */ dberr_t lock_clust_rec_modify_check_and_lock( /*=================================*/ ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG bit is set, does nothing */ const buf_block_t* block, /*!< in: buffer block of rec */ const rec_t* rec, /*!< in: record which should be modified */ dict_index_t* index, /*!< in: clustered index */ const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */ que_thr_t* thr) /*!< in: query thread */ MY_ATTRIBUTE((warn_unused_result)); /*********************************************************************//** Checks if locks of other transactions prevent an immediate modify (delete mark or delete unmark) of a secondary index record. @return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */ dberr_t lock_sec_rec_modify_check_and_lock( /*===============================*/ ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG bit is set, does nothing */ buf_block_t* block, /*!< in/out: buffer block of rec */ const rec_t* rec, /*!< in: record which should be modified; NOTE: as this is a secondary index, we always have to modify the clustered index record first: see the comment below */ dict_index_t* index, /*!< in: secondary index */ que_thr_t* thr, /*!< in: query thread (can be NULL if BTR_NO_LOCKING_FLAG) */ mtr_t* mtr) /*!< in/out: mini-transaction */ MY_ATTRIBUTE((warn_unused_result)); /*********************************************************************//** Like lock_clust_rec_read_check_and_lock(), but reads a secondary index record. @return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */ dberr_t lock_sec_rec_read_check_and_lock( /*=============================*/ ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG bit is set, does nothing */ const buf_block_t* block, /*!< in: buffer block of rec */ const rec_t* rec, /*!< in: user record or page supremum record which should be read or passed over by a read cursor */ dict_index_t* index, /*!< in: secondary index */ const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */ lock_mode mode, /*!< in: mode of the lock which the read cursor should set on records: LOCK_S or LOCK_X; the latter is possible in SELECT FOR UPDATE */ ulint gap_mode,/*!< in: LOCK_ORDINARY, LOCK_GAP, or LOCK_REC_NOT_GAP */ que_thr_t* thr); /*!< in: query thread */ /*********************************************************************//** Checks if locks of other transactions prevent an immediate read, or passing over by a read cursor, of a clustered index record. If they do, first tests if the query thread should anyway be suspended for some reason; if not, then puts the transaction and the query thread to the lock wait state and inserts a waiting request for a record lock to the lock queue. Sets the requested mode lock on the record. @return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */ dberr_t lock_clust_rec_read_check_and_lock( /*===============================*/ ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG bit is set, does nothing */ const buf_block_t* block, /*!< in: buffer block of rec */ const rec_t* rec, /*!< in: user record or page supremum record which should be read or passed over by a read cursor */ dict_index_t* index, /*!< in: clustered index */ const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */ lock_mode mode, /*!< in: mode of the lock which the read cursor should set on records: LOCK_S or LOCK_X; the latter is possible in SELECT FOR UPDATE */ ulint gap_mode,/*!< in: LOCK_ORDINARY, LOCK_GAP, or LOCK_REC_NOT_GAP */ que_thr_t* thr); /*!< in: query thread */ /*********************************************************************//** Checks if locks of other transactions prevent an immediate read, or passing over by a read cursor, of a clustered index record. If they do, first tests if the query thread should anyway be suspended for some reason; if not, then puts the transaction and the query thread to the lock wait state and inserts a waiting request for a record lock to the lock queue. Sets the requested mode lock on the record. This is an alternative version of lock_clust_rec_read_check_and_lock() that does not require the parameter "offsets". @return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */ dberr_t lock_clust_rec_read_check_and_lock_alt( /*===================================*/ ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG bit is set, does nothing */ const buf_block_t* block, /*!< in: buffer block of rec */ const rec_t* rec, /*!< in: user record or page supremum record which should be read or passed over by a read cursor */ dict_index_t* index, /*!< in: clustered index */ lock_mode mode, /*!< in: mode of the lock which the read cursor should set on records: LOCK_S or LOCK_X; the latter is possible in SELECT FOR UPDATE */ ulint gap_mode,/*!< in: LOCK_ORDINARY, LOCK_GAP, or LOCK_REC_NOT_GAP */ que_thr_t* thr) /*!< in: query thread */ MY_ATTRIBUTE((warn_unused_result)); /*********************************************************************//** Checks that a record is seen in a consistent read. @return true if sees, or false if an earlier version of the record should be retrieved */ bool lock_clust_rec_cons_read_sees( /*==========================*/ const rec_t* rec, /*!< in: user record which should be read or passed over by a read cursor */ dict_index_t* index, /*!< in: clustered index */ const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */ ReadView* view); /*!< in: consistent read view */ /*********************************************************************//** Checks that a non-clustered index record is seen in a consistent read. NOTE that a non-clustered index page contains so little information on its modifications that also in the case false, the present version of rec may be the right, but we must check this from the clustered index record. @return true if certainly sees, or false if an earlier version of the clustered index record might be needed */ bool lock_sec_rec_cons_read_sees( /*========================*/ const rec_t* rec, /*!< in: user record which should be read or passed over by a read cursor */ const dict_index_t* index, /*!< in: index */ const ReadView* view) /*!< in: consistent read view */ MY_ATTRIBUTE((warn_unused_result)); /*********************************************************************//** Locks the specified database table in the mode given. If the lock cannot be granted immediately, the query thread is put to wait. @return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */ dberr_t lock_table( /*=======*/ ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG bit is set, does nothing */ dict_table_t* table, /*!< in/out: database table in dictionary cache */ lock_mode mode, /*!< in: lock mode */ que_thr_t* thr) /*!< in: query thread */ MY_ATTRIBUTE((warn_unused_result)); /*********************************************************************//** Creates a table IX lock object for a resurrected transaction. */ void lock_table_ix_resurrect( /*====================*/ dict_table_t* table, /*!< in/out: table */ trx_t* trx); /*!< in/out: transaction */ /** Sets a lock on a table based on the given mode. @param[in] table table to lock @param[in,out] trx transaction @param[in] mode LOCK_X or LOCK_S @return error code or DB_SUCCESS. */ dberr_t lock_table_for_trx( dict_table_t* table, trx_t* trx, enum lock_mode mode) MY_ATTRIBUTE((nonnull, warn_unused_result)); /*************************************************************//** Removes a granted record lock of a transaction from the queue and grants locks to other transactions waiting in the queue if they now are entitled to a lock. */ void lock_rec_unlock( /*============*/ trx_t* trx, /*!< in/out: transaction that has set a record lock */ const buf_block_t* block, /*!< in: buffer block containing rec */ const rec_t* rec, /*!< in: record */ lock_mode lock_mode);/*!< in: LOCK_S or LOCK_X */ /*********************************************************************//** Releases a transaction's locks, and releases possible other transactions waiting because of these locks. Change the state of the transaction to TRX_STATE_COMMITTED_IN_MEMORY. */ void lock_trx_release_locks( /*===================*/ trx_t* trx); /*!< in/out: transaction */ /*********************************************************************//** Removes locks on a table to be dropped or truncated. If remove_also_table_sx_locks is TRUE then table-level S and X locks are also removed in addition to other table-level and record-level locks. No lock, that is going to be removed, is allowed to be a wait lock. */ void lock_remove_all_on_table( /*=====================*/ dict_table_t* table, /*!< in: table to be dropped or truncated */ ibool remove_also_table_sx_locks);/*!< in: also removes table S and X locks */ /*********************************************************************//** Calculates the fold value of a page file address: used in inserting or searching for a lock in the hash table. @return folded value */ UNIV_INLINE ulint lock_rec_fold( /*==========*/ ulint space, /*!< in: space */ ulint page_no)/*!< in: page number */ MY_ATTRIBUTE((const)); /*********************************************************************//** Calculates the hash value of a page file address: used in inserting or searching for a lock in the hash table. @return hashed value */ UNIV_INLINE ulint lock_rec_hash( /*==========*/ ulint space, /*!< in: space */ ulint page_no);/*!< in: page number */ /*************************************************************//** Get the lock hash table */ UNIV_INLINE hash_table_t* lock_hash_get( /*==========*/ ulint mode); /*!< in: lock mode */ /**********************************************************************//** Looks for a set bit in a record lock bitmap. Returns ULINT_UNDEFINED, if none found. @return bit index == heap number of the record, or ULINT_UNDEFINED if none found */ ulint lock_rec_find_set_bit( /*==================*/ const lock_t* lock); /*!< in: record lock with at least one bit set */ /*********************************************************************//** Gets the source table of an ALTER TABLE transaction. The table must be covered by an IX or IS table lock. @return the source table of transaction, if it is covered by an IX or IS table lock; dest if there is no source table, and NULL if the transaction is locking more than two tables or an inconsistency is found */ dict_table_t* lock_get_src_table( /*===============*/ trx_t* trx, /*!< in: transaction */ dict_table_t* dest, /*!< in: destination of ALTER TABLE */ lock_mode* mode); /*!< out: lock mode of the source table */ /*********************************************************************//** Determine if the given table is exclusively "owned" by the given transaction, i.e., transaction holds LOCK_IX and possibly LOCK_AUTO_INC on the table. @return TRUE if table is only locked by trx, with LOCK_IX, and possibly LOCK_AUTO_INC */ ibool lock_is_table_exclusive( /*====================*/ const dict_table_t* table, /*!< in: table */ const trx_t* trx); /*!< in: transaction */ /*********************************************************************//** Checks if a lock request lock1 has to wait for request lock2. @return TRUE if lock1 has to wait for lock2 to be removed */ ibool lock_has_to_wait( /*=============*/ const lock_t* lock1, /*!< in: waiting lock */ const lock_t* lock2); /*!< in: another lock; NOTE that it is assumed that this has a lock bit set on the same record as in lock1 if the locks are record locks */ /*********************************************************************//** Reports that a transaction id is insensible, i.e., in the future. */ void lock_report_trx_id_insanity( /*========================*/ trx_id_t trx_id, /*!< in: trx id */ const rec_t* rec, /*!< in: user record */ dict_index_t* index, /*!< in: index */ const ulint* offsets, /*!< in: rec_get_offsets(rec, index) */ trx_id_t max_trx_id); /*!< in: trx_sys_get_max_trx_id() */ /*********************************************************************//** Prints info of a table lock. */ void lock_table_print( /*=============*/ FILE* file, /*!< in: file where to print */ const lock_t* lock); /*!< in: table type lock */ /*********************************************************************//** Prints info of a record lock. */ void lock_rec_print( /*===========*/ FILE* file, /*!< in: file where to print */ const lock_t* lock); /*!< in: record type lock */ /*********************************************************************//** Prints info of locks for all transactions. @return FALSE if not able to obtain lock mutex and exits without printing info */ ibool lock_print_info_summary( /*====================*/ FILE* file, /*!< in: file where to print */ ibool nowait) /*!< in: whether to wait for the lock mutex */ MY_ATTRIBUTE((warn_unused_result)); /** Prints transaction lock wait and MVCC state. @param[in,out] file file where to print @param[in] trx transaction */ void lock_trx_print_wait_and_mvcc_state( FILE* file, const trx_t* trx); /*********************************************************************//** Prints info of locks for each transaction. This function assumes that the caller holds the lock mutex and more importantly it will release the lock mutex on behalf of the caller. (This should be fixed in the future). */ void lock_print_info_all_transactions( /*=============================*/ FILE* file); /*!< in: file where to print */ /*********************************************************************//** Return approximate number or record locks (bits set in the bitmap) for this transaction. Since delete-marked records may be removed, the record count will not be precise. The caller must be holding lock_sys->mutex. */ ulint lock_number_of_rows_locked( /*=======================*/ const trx_lock_t* trx_lock) /*!< in: transaction locks */ MY_ATTRIBUTE((warn_unused_result)); /*********************************************************************//** Return the number of table locks for a transaction. The caller must be holding lock_sys->mutex. */ ulint lock_number_of_tables_locked( /*=========================*/ const trx_lock_t* trx_lock) /*!< in: transaction locks */ MY_ATTRIBUTE((warn_unused_result)); /*******************************************************************//** Gets the type of a lock. Non-inline version for using outside of the lock module. @return LOCK_TABLE or LOCK_REC */ ulint lock_get_type( /*==========*/ const lock_t* lock); /*!< in: lock */ /*******************************************************************//** Gets the trx of the lock. Non-inline version for using outside of the lock module. @return trx_t* */ UNIV_INTERN trx_t* lock_get_trx( /*=========*/ const lock_t* lock); /*!< in: lock */ /*******************************************************************//** Gets the id of the transaction owning a lock. @return transaction id */ trx_id_t lock_get_trx_id( /*============*/ const lock_t* lock); /*!< in: lock */ /*******************************************************************//** Gets the mode of a lock in a human readable string. The string should not be free()'d or modified. @return lock mode */ const char* lock_get_mode_str( /*==============*/ const lock_t* lock); /*!< in: lock */ /*******************************************************************//** Gets the type of a lock in a human readable string. The string should not be free()'d or modified. @return lock type */ const char* lock_get_type_str( /*==============*/ const lock_t* lock); /*!< in: lock */ /*******************************************************************//** Gets the id of the table on which the lock is. @return id of the table */ table_id_t lock_get_table_id( /*==============*/ const lock_t* lock); /*!< in: lock */ /** Determine which table a lock is associated with. @param[in] lock the lock @return name of the table */ const table_name_t& lock_get_table_name( const lock_t* lock); /*******************************************************************//** For a record lock, gets the index on which the lock is. @return index */ const dict_index_t* lock_rec_get_index( /*===============*/ const lock_t* lock); /*!< in: lock */ /*******************************************************************//** For a record lock, gets the name of the index on which the lock is. The string should not be free()'d or modified. @return name of the index */ const char* lock_rec_get_index_name( /*====================*/ const lock_t* lock); /*!< in: lock */ /*******************************************************************//** For a record lock, gets the tablespace number on which the lock is. @return tablespace number */ ulint lock_rec_get_space_id( /*==================*/ const lock_t* lock); /*!< in: lock */ /*******************************************************************//** For a record lock, gets the page number on which the lock is. @return page number */ ulint lock_rec_get_page_no( /*=================*/ const lock_t* lock); /*!< in: lock */ /*******************************************************************//** Check if there are any locks (table or rec) against table. @return TRUE if locks exist */ bool lock_table_has_locks( /*=================*/ const dict_table_t* table); /*!< in: check if there are any locks held on records in this table or on the table itself */ /*********************************************************************//** A thread which wakes up threads whose lock wait may have lasted too long. @return a dummy parameter */ extern "C" os_thread_ret_t DECLARE_THREAD(lock_wait_timeout_thread)( /*=====================================*/ void* arg); /*!< in: a dummy parameter required by os_thread_create */ /********************************************************************//** Releases a user OS thread waiting for a lock to be released, if the thread is already suspended. */ void lock_wait_release_thread_if_suspended( /*==================================*/ que_thr_t* thr); /*!< in: query thread associated with the user OS thread */ /***************************************************************//** Puts a user OS thread to wait for a lock to be released. If an error occurs during the wait trx->error_state associated with thr is != DB_SUCCESS when we return. DB_LOCK_WAIT_TIMEOUT and DB_DEADLOCK are possible errors. DB_DEADLOCK is returned if selective deadlock resolution chose this transaction as a victim. */ void lock_wait_suspend_thread( /*=====================*/ que_thr_t* thr); /*!< in: query thread associated with the user OS thread */ /*********************************************************************//** Unlocks AUTO_INC type locks that were possibly reserved by a trx. This function should be called at the the end of an SQL statement, by the connection thread that owns the transaction (trx->mysql_thd). */ void lock_unlock_table_autoinc( /*======================*/ trx_t* trx); /*!< in/out: transaction */ /*********************************************************************//** Check whether the transaction has already been rolled back because it was selected as a deadlock victim, or if it has to wait then cancel the wait lock. @return DB_DEADLOCK, DB_LOCK_WAIT or DB_SUCCESS */ dberr_t lock_trx_handle_wait( /*=================*/ trx_t* trx, /*!< in/out: trx lock state */ bool lock_mutex_taken, bool trx_mutex_taken) MY_ATTRIBUTE((nonnull(1), warn_unused_result)); /*********************************************************************//** Get the number of locks on a table. @return number of locks */ ulint lock_table_get_n_locks( /*===================*/ const dict_table_t* table); /*!< in: table */ /*******************************************************************//** Initialise the trx lock list. */ void lock_trx_lock_list_init( /*====================*/ trx_lock_list_t* lock_list); /*!< List to initialise */ /*******************************************************************//** Set the lock system timeout event. */ void lock_set_timeout_event(); /*====================*/ #ifdef UNIV_DEBUG /*********************************************************************//** Checks that a transaction id is sensible, i.e., not in the future. @return true if ok */ bool lock_check_trx_id_sanity( /*=====================*/ trx_id_t trx_id, /*!< in: trx id */ const rec_t* rec, /*!< in: user record */ dict_index_t* index, /*!< in: index */ const ulint* offsets) /*!< in: rec_get_offsets(rec, index) */ MY_ATTRIBUTE((warn_unused_result)); /*******************************************************************//** Check if the transaction holds any locks on the sys tables or its records. @return the strongest lock found on any sys table or 0 for none */ const lock_t* lock_trx_has_sys_table_locks( /*=========================*/ const trx_t* trx) /*!< in: transaction to check */ MY_ATTRIBUTE((warn_unused_result)); /*******************************************************************//** Check if the transaction holds an exclusive lock on a record. @return whether the locks are held */ bool lock_trx_has_rec_x_lock( /*====================*/ const trx_t* trx, /*!< in: transaction to check */ const dict_table_t* table, /*!< in: table to check */ const buf_block_t* block, /*!< in: buffer block of the record */ ulint heap_no)/*!< in: record heap number */ MY_ATTRIBUTE((warn_unused_result)); #endif /* UNIV_DEBUG */ /** Allocate cached locks for the transaction. @param trx allocate cached record locks for this transaction */ void lock_trx_alloc_locks(trx_t* trx); /** Lock modes and types */ /* @{ */ #define LOCK_MODE_MASK 0xFUL /*!< mask used to extract mode from the type_mode field in a lock */ /** Lock types */ /* @{ */ #define LOCK_TABLE 16 /*!< table lock */ #define LOCK_REC 32 /*!< record lock */ #define LOCK_TYPE_MASK 0xF0UL /*!< mask used to extract lock type from the type_mode field in a lock */ #if LOCK_MODE_MASK & LOCK_TYPE_MASK # error "LOCK_MODE_MASK & LOCK_TYPE_MASK" #endif #define LOCK_WAIT 256 /*!< Waiting lock flag; when set, it means that the lock has not yet been granted, it is just waiting for its turn in the wait queue */ /* Precise modes */ #define LOCK_ORDINARY 0 /*!< this flag denotes an ordinary next-key lock in contrast to LOCK_GAP or LOCK_REC_NOT_GAP */ #define LOCK_GAP 512 /*!< when this bit is set, it means that the lock holds only on the gap before the record; for instance, an x-lock on the gap does not give permission to modify the record on which the bit is set; locks of this type are created when records are removed from the index chain of records */ #define LOCK_REC_NOT_GAP 1024 /*!< this bit means that the lock is only on the index record and does NOT block inserts to the gap before the index record; this is used in the case when we retrieve a record with a unique key, and is also used in locking plain SELECTs (not part of UPDATE or DELETE) when the user has set the READ COMMITTED isolation level */ #define LOCK_INSERT_INTENTION 2048 /*!< this bit is set when we place a waiting gap type record lock request in order to let an insert of an index record to wait until there are no conflicting locks by other transactions on the gap; note that this flag remains set when the waiting lock is granted, or if the lock is inherited to a neighboring record */ #define LOCK_PREDICATE 8192 /*!< Predicate lock */ #define LOCK_PRDT_PAGE 16384 /*!< Page lock */ #if (LOCK_WAIT|LOCK_GAP|LOCK_REC_NOT_GAP|LOCK_INSERT_INTENTION|LOCK_PREDICATE|LOCK_PRDT_PAGE)&LOCK_MODE_MASK # error #endif #if (LOCK_WAIT|LOCK_GAP|LOCK_REC_NOT_GAP|LOCK_INSERT_INTENTION|LOCK_PREDICATE|LOCK_PRDT_PAGE)&LOCK_TYPE_MASK # error #endif /* @} */ /** Lock operation struct */ struct lock_op_t{ dict_table_t* table; /*!< table to be locked */ lock_mode mode; /*!< lock mode */ }; typedef ib_mutex_t LockMutex; /** The lock system struct */ struct lock_sys_t{ char pad1[CACHE_LINE_SIZE]; /*!< padding to prevent other memory update hotspots from residing on the same memory cache line */ LockMutex mutex; /*!< Mutex protecting the locks */ hash_table_t* rec_hash; /*!< hash table of the record locks */ hash_table_t* prdt_hash; /*!< hash table of the predicate lock */ hash_table_t* prdt_page_hash; /*!< hash table of the page lock */ char pad2[CACHE_LINE_SIZE]; /*!< Padding */ LockMutex wait_mutex; /*!< Mutex protecting the next two fields */ srv_slot_t* waiting_threads; /*!< Array of user threads suspended while waiting for locks within InnoDB, protected by the lock_sys->wait_mutex */ srv_slot_t* last_slot; /*!< highest slot ever used in the waiting_threads array, protected by lock_sys->wait_mutex */ ibool rollback_complete; /*!< TRUE if rollback of all recovered transactions is complete. Protected by lock_sys->mutex */ ulint n_lock_max_wait_time; /*!< Max wait time */ os_event_t timeout_event; /*!< Set to the event that is created in the lock wait monitor thread. A value of 0 means the thread is not active */ bool timeout_thread_active; /*!< True if the timeout thread is running */ }; /*************************************************************//** Removes a record lock request, waiting or granted, from the queue. */ void lock_rec_discard( /*=============*/ lock_t* in_lock); /*!< in: record lock object: all record locks which are contained in this lock object are removed */ /*************************************************************//** Moves the explicit locks on user records to another page if a record list start is moved to another page. */ void lock_rtr_move_rec_list( /*===================*/ const buf_block_t* new_block, /*!< in: index page to move to */ const buf_block_t* block, /*!< in: index page */ rtr_rec_move_t* rec_move, /*!< in: recording records moved */ ulint num_move); /*!< in: num of rec to move */ /*************************************************************//** Removes record lock objects set on an index page which is discarded. This function does not move locks, or check for waiting locks, therefore the lock bitmaps must already be reset when this function is called. */ void lock_rec_free_all_from_discard_page( /*================================*/ const buf_block_t* block); /*!< in: page to be discarded */ /** Reset the nth bit of a record lock. @param[in,out] lock record lock @param[in] i index of the bit that will be reset @param[in] type whether the lock is in wait mode */ void lock_rec_trx_wait( lock_t* lock, ulint i, ulint type); /** The lock system */ extern lock_sys_t* lock_sys; /** Test if lock_sys->mutex can be acquired without waiting. */ #define lock_mutex_enter_nowait() \ (lock_sys->mutex.trylock(__FILE__, __LINE__)) /** Test if lock_sys->mutex is owned. */ #define lock_mutex_own() (lock_sys->mutex.is_owned()) /** Acquire the lock_sys->mutex. */ #define lock_mutex_enter() do { \ mutex_enter(&lock_sys->mutex); \ } while (0) /** Release the lock_sys->mutex. */ #define lock_mutex_exit() do { \ lock_sys->mutex.exit(); \ } while (0) /** Test if lock_sys->wait_mutex is owned. */ #define lock_wait_mutex_own() (lock_sys->wait_mutex.is_owned()) /** Acquire the lock_sys->wait_mutex. */ #define lock_wait_mutex_enter() do { \ mutex_enter(&lock_sys->wait_mutex); \ } while (0) /** Release the lock_sys->wait_mutex. */ #define lock_wait_mutex_exit() do { \ lock_sys->wait_mutex.exit(); \ } while (0) #ifdef WITH_WSREP /*********************************************************************//** Cancels a waiting lock request and releases possible other transactions waiting behind it. */ UNIV_INTERN void lock_cancel_waiting_and_release( /*============================*/ lock_t* lock); /*!< in/out: waiting lock request */ /*******************************************************************//** Get lock mode and table/index name @return string containing lock info */ std::string lock_get_info( const lock_t*); /*************************************************************//** Updates the lock table when a page is split and merged to two pages. */ UNIV_INTERN void lock_update_split_and_merge( const buf_block_t* left_block, /*!< in: left page to which merged */ const rec_t* orig_pred, /*!< in: original predecessor of supremum on the left page before merge*/ const buf_block_t* right_block);/*!< in: right page from which merged */ #endif /* WITH_WSREP */ #ifndef UNIV_NONINL #include "lock0lock.ic" #endif #endif