lock0lock.h

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

/*************************************************************************
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