mariadb/storage/innobase/include/lock0lock.h
aivanov@mysql.com d33b523271 Applied innodb-5.1-ss269 snapshot.
Fixed BUGS:
  #3300: "UPDATE statement with no index column in where condition locks
    all rows"
    Implement semi-consistent read to reduce lock conflicts at the cost
    of breaking serializability.
    ha_innobase::unlock_row(): reset the "did semi consistent read" flag
    ha_innobase::was_semi_consistent_read(),
    ha_innobase::try_semi_consistent_read(): new methods
    row_prebuilt_t, row_create_prebuilt(): add field row_read_type for
    keeping track of semi-consistent reads
    row_vers_build_for_semi_consistent_read(),
    row_sel_build_committed_vers_for_mysql(): new functions
    row_search_for_mysql(): implement semi-consistent reads

  #9802: "Foreign key checks disallow alter table".
    Added test cases.

  #12456: "Cursor shows incorrect data - DML does not affect,
    probably caching"
    This patch implements a high-granularity read view to be used with
    cursors. In this high-granularity consistent read view modifications 
    done by the creating transaction after the cursor is created or 
   future transactions are not visible. But those modifications that 
   transaction did before the cursor was created are visible.

  #12701: "Support >4GB buffer pool and log files on 64-bit Windows"
    Do not call os_file_create_tmpfile() at runtime. Instead, create all
    tempfiles at startup and guard access to them with mutexes.

  #13778: "If FOREIGN_KEY_CHECKS=0, one can create inconsistent FOREIGN KEYs".
    When FOREIGN_KEY_CHECKS=0 we still need to check that datatypes between
    foreign key references are compatible.

  #14189: "VARBINARY and BINARY variables: trailing space ignored with InnoDB"
    innobase_init(): Assert that
    DATA_MYSQL_BINARY_CHARSET_COLL == my_charset_bin.number.
    dtype_get_pad_char(): Do not pad VARBINARY or BINARY columns.
    row_ins_cascade_calc_update_vec(): Refuse ON UPDATE CASCADE when trying
    to change the length of a VARBINARY column that refers to or is referenced
    by a BINARY column. BINARY columns are no longer padded on comparison,
    and thus they cannot be padded on storage either.

  #14747: "Race condition can cause btr_search_drop_page_hash_index() to crash"
    Note that buf_block_t::index should be protected by btr_search_latch
    or an s-latch or x-latch on the index page.
    btr_search_drop_page_hash_index(): Read block->index while holding
    btr_search_latch and use the cached value in the loop.  Remove some
    redundant assertions.

  #15108: "mysqld crashes when innodb_log_file_size is set > 4G"

  #15308: "Problem of Order with Enum Column in Primary Key"

  #15550: "mysqld crashes in printing a FOREIGN KEY error in InnoDB"
    row_ins_foreign_report_add_err(): When printing the parent record,
    use the index in the parent table rather than the index in the child table.

  #15653: "Slow inserts to InnoDB if many thousands of .ibd files"
    Keep track on unflushed modifications to file spaces.  When there are tens
    of thousands of file spaces, flushing all files in fil_flush_file_spaces()
    would be very slow.
    fil_flush_file_spaces(): Only flush unflushed file spaces.
    fil_space_t, fil_system_t: Add a list of unflushed spaces.

  #15991: "innodb-file-per-table + symlink database + rename = cr"
   os_file_handle_error(): Map the error codes EXDEV, ENOTDIR, and EISDIR
   to the new code OS_FILE_PATH_ERROR. Treat this code as OS_FILE_PATH_ERROR.
   This fixes the crash on RENAME TABLE when the .ibd file is a symbolic link
   to a different file system.

  #16157: "InnoDB crashes when main location settings are empty"
    This patch is from Heikki.

  #16298: "InnoDB segfaults in INSERTs in upgrade of 4.0 -> 5.0 tables
    with VARCHAR BINARY"
    dict_load_columns(): Set the charset-collation code
    DATA_MYSQL_BINARY_CHARSET_COLL for those binary string columns
    that lack a charset-collation code, i.e., the tables were created
    with an older version of MySQL/InnoDB than 4.1.2.

  #16229: "MySQL/InnoDB uses full explicit table locks in trigger processing"
    Take a InnoDB table lock only if user has explicitly requested a table
    lock. Added some additional comments to store_lock() and external_lock().

  #16387: "InnoDB crash when dropping a foreign key <table>_ibfk_0"
    Do not mistake TABLENAME_ibfk_0 for auto-generated id.
    dict_table_get_highest_foreign_id(): Ignore foreign constraint
    identifiers starting with the pattern TABLENAME_ibfk_0.

  #16582: "InnoDB: Error in an adaptive hash index pointer to page"
    Account for a race condition when dropping the adaptive hash index
    for a B-tree page.
    btr_search_drop_page_hash_index(): Retry the operation if a hash index
    with different parameters was built meanwhile.  Add diagnostics for the
    case that hash node pointers to the page remain.
    btr_search_info_update_hash(), btr_search_info_update_slow():
    Document the parameter "info" as in/out.

  #16814: "SHOW INNODB STATUS format error in LATEST FOREIGN KEY ERROR
    section"
    Add a missing newline to the LAST FOREIGN KEY ERROR section in SHOW
    INNODB STATUS output.
    dict_foreign_error_report(): Always print a newline after invoking
    dict_print_info_on_foreign_key_in_create_format().

  #16827: "Better InnoDB error message if ibdata files omitted from my.cnf"

  #17126: "CHECK TABLE on InnoDB causes a short hang during check of adaptive
    hash"
    CHECK TABLE blocking other queries, by releasing the btr_search_latch
    periodically during the adaptive hash table validation.

  #17405: "Valgrind: conditional jump or move depends on unititialised values"
    buf_block_init(): Reset magic_n, buf_fix_count and io_fix to avoid
    testing uninitialized variables.
2006-03-10 19:22:21 +03:00

681 lines
25 KiB
C

/******************************************************
The transaction lock system
(c) 1996 Innobase Oy
Created 5/7/1996 Heikki Tuuri
*******************************************************/
#ifndef lock0lock_h
#define lock0lock_h
#include "univ.i"
#include "trx0types.h"
#include "rem0types.h"
#include "dict0types.h"
#include "que0types.h"
#include "page0types.h"
#include "lock0types.h"
#include "read0types.h"
#include "hash0hash.h"
#ifdef UNIV_DEBUG
extern ibool lock_print_waits;
#endif /* UNIV_DEBUG */
/* Buffer for storing information about the most recent deadlock error */
extern FILE* lock_latest_err_file;
/*************************************************************************
Gets the size of a lock struct. */
ulint
lock_get_size(void);
/*===============*/
/* out: size in bytes */
/*************************************************************************
Creates the lock system at database start. */
void
lock_sys_create(
/*============*/
ulint n_cells); /* in: number of slots in lock hash table */
/*************************************************************************
Checks if some transaction has an implicit x-lock on a record in a secondary
index. */
trx_t*
lock_sec_rec_some_has_impl_off_kernel(
/*==================================*/
/* out: transaction which has the x-lock, or
NULL */
rec_t* rec, /* in: user record */
dict_index_t* index, /* in: secondary index */
const ulint* offsets);/* in: rec_get_offsets(rec, index) */
/*************************************************************************
Checks if some transaction has an implicit x-lock on a record in a clustered
index. */
UNIV_INLINE
trx_t*
lock_clust_rec_some_has_impl(
/*=========================*/
/* out: transaction which has the x-lock, or
NULL */
rec_t* rec, /* in: user record */
dict_index_t* index, /* in: clustered index */
const ulint* offsets);/* in: rec_get_offsets(rec, index) */
/*****************************************************************
Makes a record to inherit the locks of another record as gap type
locks, but does not reset the lock bits of the other record. Also
waiting lock requests on rec are inherited as GRANTED gap locks. */
void
lock_rec_inherit_to_gap(
/*====================*/
rec_t* heir, /* in: record which inherits */
rec_t* rec); /* in: record from which inherited; does NOT reset
the locks on this record */
/*****************************************************************
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(
/*======================*/
page_t* page, /* in: old index page */
page_t* new_page); /* in: 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(
/*===================*/
page_t* new_page, /* in: index page to move to */
page_t* page, /* in: index page */
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(
/*=====================*/
page_t* new_page, /* in: index page to move to */
page_t* page, /* in: index page */
rec_t* rec, /* in: record on page: this is the
first record NOT copied */
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(
/*====================*/
page_t* right_page, /* in: right page */
page_t* left_page); /* in: left page */
/*****************************************************************
Updates the lock table when a page is merged to the right. */
void
lock_update_merge_right(
/*====================*/
rec_t* orig_succ, /* in: original successor of infimum
on the right page before merge */
page_t* left_page); /* 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(
/*===================*/
page_t* new_page, /* in: index page to which copied */
page_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(
/*=========================*/
page_t* new_page, /* in: index page to which copied */
page_t* page); /* in: index page; NOT the root! */
/*****************************************************************
Updates the lock table when a page is split to the left. */
void
lock_update_split_left(
/*===================*/
page_t* right_page, /* in: right page */
page_t* left_page); /* in: left page */
/*****************************************************************
Updates the lock table when a page is merged to the left. */
void
lock_update_merge_left(
/*===================*/
page_t* left_page, /* in: left page to which merged */
rec_t* orig_pred, /* in: original predecessor of supremum
on the left page before merge */
page_t* right_page); /* in: merged index page which will be
discarded */
/*****************************************************************
Resets the original locks on heir and replaces them with gap type locks
inherited from rec. */
void
lock_rec_reset_and_inherit_gap_locks(
/*=================================*/
rec_t* heir, /* in: heir record */
rec_t* rec); /* in: record */
/*****************************************************************
Updates the lock table when a page is discarded. */
void
lock_update_discard(
/*================*/
rec_t* heir, /* in: record which will inherit the locks */
page_t* page); /* in: index page which will be discarded */
/*****************************************************************
Updates the lock table when a new user record is inserted. */
void
lock_update_insert(
/*===============*/
rec_t* rec); /* in: the inserted record */
/*****************************************************************
Updates the lock table when a record is removed. */
void
lock_update_delete(
/*===============*/
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(
/*===========================*/
page_t* page, /* in: page containing the record */
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(
/*===============================*/
rec_t* rec, /* in: record whose lock state is restored */
page_t* page); /* in: page (rec is not necessarily on this page)
whose infimum stored the lock state; lock bits are
reset on the infimum */
/*************************************************************************
Returns TRUE if there are explicit record locks on a page. */
ibool
lock_rec_expl_exist_on_page(
/*========================*/
/* out: TRUE if there are explicit record locks on
the page */
ulint space, /* in: space id */
ulint page_no);/* in: page number */
/*************************************************************************
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. */
ulint
lock_rec_insert_check_and_lock(
/*===========================*/
/* out: DB_SUCCESS, DB_LOCK_WAIT,
DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
ulint flags, /* in: if BTR_NO_LOCKING_FLAG bit is set,
does nothing */
rec_t* rec, /* in: record after which to insert */
dict_index_t* index, /* in: index */
que_thr_t* thr, /* in: query thread */
ibool* inherit);/* out: set to TRUE if the new inserted
record maybe should inherit LOCK_GAP type
locks from the successor record */
/*************************************************************************
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. */
ulint
lock_clust_rec_modify_check_and_lock(
/*=================================*/
/* out: DB_SUCCESS, DB_LOCK_WAIT,
DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
ulint flags, /* in: if BTR_NO_LOCKING_FLAG bit is set,
does nothing */
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 */
/*************************************************************************
Checks if locks of other transactions prevent an immediate modify
(delete mark or delete unmark) of a secondary index record. */
ulint
lock_sec_rec_modify_check_and_lock(
/*===============================*/
/* out: DB_SUCCESS, DB_LOCK_WAIT,
DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
ulint flags, /* in: if BTR_NO_LOCKING_FLAG bit is set,
does nothing */
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 */
/*************************************************************************
Like the counterpart for a clustered index below, but now we read a
secondary index record. */
ulint
lock_sec_rec_read_check_and_lock(
/*=============================*/
/* out: DB_SUCCESS, DB_LOCK_WAIT,
DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
ulint flags, /* in: if BTR_NO_LOCKING_FLAG bit is set,
does nothing */
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) */
ulint 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. */
ulint
lock_clust_rec_read_check_and_lock(
/*===============================*/
/* out: DB_SUCCESS, DB_LOCK_WAIT,
DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
ulint flags, /* in: if BTR_NO_LOCKING_FLAG bit is set,
does nothing */
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) */
ulint 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". */
ulint
lock_clust_rec_read_check_and_lock_alt(
/*===================================*/
/* out: DB_SUCCESS, DB_LOCK_WAIT,
DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
ulint flags, /* in: if BTR_NO_LOCKING_FLAG bit is set,
does nothing */
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 */
ulint 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 that a record is seen in a consistent read. */
ibool
lock_clust_rec_cons_read_sees(
/*==========================*/
/* out: TRUE if sees, or FALSE if an earlier
version of the record should be retrieved */
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) */
read_view_t* view); /* in: consistent read view */
/*************************************************************************
Checks that a non-clustered index record is seen in a consistent read. */
ulint
lock_sec_rec_cons_read_sees(
/*========================*/
/* out: TRUE if certainly sees, or FALSE if an
earlier version of the clustered index record
might be needed: 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 */
rec_t* rec, /* in: user record which should be read or
passed over by a read cursor */
dict_index_t* index, /* in: non-clustered index */
read_view_t* view); /* in: consistent read view */
/*************************************************************************
Locks the specified database table in the mode given. If the lock cannot
be granted immediately, the query thread is put to wait. */
ulint
lock_table(
/*=======*/
/* out: DB_SUCCESS, DB_LOCK_WAIT,
DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
ulint flags, /* in: if BTR_NO_LOCKING_FLAG bit is set,
does nothing */
dict_table_t* table, /* in: database table in dictionary cache */
ulint mode, /* in: lock mode */
que_thr_t* thr); /* in: query thread */
/*************************************************************************
Checks if there are any locks set on the table. */
ibool
lock_is_on_table(
/*=============*/
/* out: TRUE if there are lock(s) */
dict_table_t* table); /* in: database table in dictionary cache */
/*****************************************************************
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: transaction that has set a record
lock */
rec_t* rec, /* in: record */
ulint lock_mode); /* in: LOCK_S or LOCK_X */
/*************************************************************************
Releases a table lock.
Releases possible other transactions waiting for this lock. */
void
lock_table_unlock(
/*==============*/
lock_t* lock); /* in: lock */
/*************************************************************************
Releases an auto-inc lock a transaction possibly has on a table.
Releases possible other transactions waiting for this lock. */
void
lock_table_unlock_auto_inc(
/*=======================*/
trx_t* trx); /* in: transaction */
/*************************************************************************
Releases transaction locks, and releases possible other transactions waiting
because of these locks. */
void
lock_release_off_kernel(
/*====================*/
trx_t* trx); /* in: transaction */
/*************************************************************************
Cancels a waiting lock request and releases possible other transactions
waiting behind it. */
void
lock_cancel_waiting_and_release(
/*============================*/
lock_t* lock); /* in: waiting lock request */
/*************************************************************************
Resets all locks, both table and record locks, on a table to be dropped.
No lock is allowed to be a wait lock. */
void
lock_reset_all_on_table(
/*====================*/
dict_table_t* table); /* in: table to be dropped */
/*************************************************************************
Calculates the fold value of a page file address: used in inserting or
searching for a lock in the hash table. */
UNIV_INLINE
ulint
lock_rec_fold(
/*==========*/
/* out: folded value */
ulint space, /* in: space */
ulint page_no);/* in: page number */
/*************************************************************************
Calculates the hash value of a page file address: used in inserting or
searching for a lock in the hash table. */
UNIV_INLINE
ulint
lock_rec_hash(
/*==========*/
/* out: hashed value */
ulint space, /* in: space */
ulint page_no);/* in: page number */
/*************************************************************************
Gets the source table of an ALTER TABLE transaction. The table must be
covered by an IX or IS table lock. */
dict_table_t*
lock_get_src_table(
/*===============*/
/* out: 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 */
trx_t* trx, /* in: transaction */
dict_table_t* dest, /* in: destination of ALTER TABLE */
ulint* 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. */
ibool
lock_is_table_exclusive(
/*====================*/
/* out: TRUE if table is only locked by trx,
with LOCK_IX, and possibly LOCK_AUTO_INC */
dict_table_t* table, /* in: table */
trx_t* trx); /* in: transaction */
/*************************************************************************
Checks that a transaction id is sensible, i.e., not in the future. */
ibool
lock_check_trx_id_sanity(
/*=====================*/
/* out: TRUE if ok */
dulint trx_id, /* in: trx id */
rec_t* rec, /* in: user record */
dict_index_t* index, /* in: clustered index */
const ulint* offsets, /* in: rec_get_offsets(rec, index) */
ibool has_kernel_mutex);/* in: TRUE if the caller owns the
kernel mutex */
/*************************************************************************
Validates the lock queue on a single record. */
ibool
lock_rec_queue_validate(
/*====================*/
/* out: TRUE if ok */
rec_t* rec, /* in: record to look at */
dict_index_t* index, /* in: index, or NULL if not known */
const ulint* offsets);/* in: rec_get_offsets(rec, index) */
/*************************************************************************
Prints info of a table lock. */
void
lock_table_print(
/*=============*/
FILE* file, /* in: file where to print */
lock_t* lock); /* in: table type lock */
/*************************************************************************
Prints info of a record lock. */
void
lock_rec_print(
/*===========*/
FILE* file, /* in: file where to print */
lock_t* lock); /* in: record type lock */
/*************************************************************************
Prints info of locks for all transactions. */
void
lock_print_info_summary(
/*====================*/
FILE* file); /* in: file where to print */
/*************************************************************************
Prints info of locks for each transaction. */
void
lock_print_info_all_transactions(
/*=============================*/
FILE* file); /* in: file where to print */
/*************************************************************************
Validates the lock queue on a table. */
ibool
lock_table_queue_validate(
/*======================*/
/* out: TRUE if ok */
dict_table_t* table); /* in: table */
/*************************************************************************
Validates the record lock queues on a page. */
ibool
lock_rec_validate_page(
/*===================*/
/* out: TRUE if ok */
ulint space, /* in: space id */
ulint page_no);/* in: page number */
/*************************************************************************
Validates the lock system. */
ibool
lock_validate(void);
/*===============*/
/* out: TRUE if ok */
/* The lock system */
extern lock_sys_t* lock_sys;
/* Lock modes and types */
/* Basic modes */
#define LOCK_NONE 0 /* this flag is used elsewhere to note
consistent read */
#define LOCK_IS 2 /* intention shared */
#define LOCK_IX 3 /* intention exclusive */
#define LOCK_S 4 /* shared */
#define LOCK_X 5 /* exclusive */
#define LOCK_AUTO_INC 6 /* locks the auto-inc counter of a table
in an exclusive mode */
#define LOCK_MODE_MASK 0xFUL /* mask used to extract mode from the
type_mode field in a lock */
/* Lock types */
#define LOCK_TABLE 16 /* these type values should be so high that */
#define LOCK_REC 32 /* they can be ORed to the lock mode */
#define LOCK_TYPE_MASK 0xF0UL /* mask used to extract lock type from the
type_mode field in a lock */
/* Waiting lock flag */
#define LOCK_WAIT 256 /* this wait bit should be so high that
it can be ORed to the lock mode and type;
when this bit is 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 /* this gap bit should be so high that
it can be ORed to the other flags;
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 */
/* When lock bits are reset, the following flags are available: */
#define LOCK_RELEASE_WAIT 1
#define LOCK_NOT_RELEASE_WAIT 2
/* Lock operation struct */
typedef struct lock_op_struct lock_op_t;
struct lock_op_struct{
dict_table_t* table; /* table to be locked */
ulint mode; /* lock mode */
};
#define LOCK_OP_START 1
#define LOCK_OP_COMPLETE 2
/* The lock system struct */
struct lock_sys_struct{
hash_table_t* rec_hash; /* hash table of the record locks */
};
/* The lock system */
extern lock_sys_t* lock_sys;
#ifndef UNIV_NONINL
#include "lock0lock.ic"
#endif
#endif