trx0sys.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

trx_t*
trx_get_on_id(
/*==========*/
			/* out: the trx handle or NULL if not found */
	dulint	trx_id);	/* in: trx id to search for */
/********************************************************************
Returns the minumum trx id in trx list. This is the smallest id for which
the trx can possibly be active. (But, you must look at the trx->conc_state to
find out if the minimum trx id transaction itself is active, or already
committed.) */
UNIV_INLINE
dulint
trx_list_get_min_trx_id(void);
/*=========================*/
			/* out: the minimum trx id, or trx_sys->max_trx_id
			if the trx list is empty */
/********************************************************************
Checks if a transaction with the given id is active. */
UNIV_INLINE
ibool
trx_is_active(
/*==========*/
			/* out: TRUE if active */
	dulint	trx_id);/* in: trx id of the transaction */
/********************************************************************
Checks that trx is in the trx list. */

ibool
trx_in_trx_list(
/*============*/
			/* out: TRUE if is in */
	trx_t*	in_trx);/* in: trx */
/*********************************************************************
Updates the offset information about the end of the MySQL binlog entry
which corresponds to the transaction just being committed. In a MySQL
replication slave updates the latest master binlog position up to which
replication has proceeded. */

void
trx_sys_update_mysql_binlog_offset(
/*===============================*/
	const char*	file_name,/* in: MySQL log file name */
	ib_longlong	offset,	/* in: position in that log file */
	ulint		field,	/* in: offset of the MySQL log info field in
				the trx sys header */
	mtr_t*		mtr);	/* in: mtr */
/*********************************************************************
Prints to stderr the MySQL binlog offset info in the trx system header if
the magic number shows it valid. */

void
trx_sys_print_mysql_binlog_offset(void);
/*===================================*/
#ifdef UNIV_HOTBACKUP
/*********************************************************************
Prints to stderr the MySQL binlog info in the system header if the
magic number shows it valid. */

void
trx_sys_print_mysql_binlog_offset_from_page(
/*========================================*/
	byte*	page);	/* in: buffer containing the trx system header page,
			i.e., page number TRX_SYS_PAGE_NO in the tablespace */
#endif /* UNIV_HOTBACKUP */
/*********************************************************************
Prints to stderr the MySQL master log offset info in the trx system header if
the magic number shows it valid. */

void
trx_sys_print_mysql_master_log_pos(void);
/*====================================*/

/* The automatically created system rollback segment has this id */
#define TRX_SYS_SYSTEM_RSEG_ID	0

/* Space id and page no where the trx system file copy resides */
#define	TRX_SYS_SPACE	0	/* the SYSTEM tablespace */
#define	TRX_SYS_PAGE_NO	FSP_TRX_SYS_PAGE_NO

/* The offset of the transaction system header on the page */
#define	TRX_SYS		FSEG_PAGE_DATA

/* Transaction system header */
/*-------------------------------------------------------------*/
#define	TRX_SYS_TRX_ID_STORE	0	/* the maximum trx id or trx number
					modulo TRX_SYS_TRX_ID_UPDATE_MARGIN
					written to a file page by any
					transaction; the assignment of
					transaction ids continues from this
					number rounded up by .._MARGIN plus
					.._MARGIN when the database is
					started */
#define TRX_SYS_FSEG_HEADER	8	/* segment header for the tablespace
					segment the trx system is created
					into */
#define	TRX_SYS_RSEGS		(8 + FSEG_HEADER_SIZE)	
					/* the start of the array of rollback
					segment specification slots */
/*-------------------------------------------------------------*/

/* Max number of rollback segments: the number of segment specification slots
in the transaction system array; rollback segment id must fit in one byte,
therefore 256; each slot is currently 8 bytes in size */
#define	TRX_SYS_N_RSEGS		256

#define TRX_SYS_MYSQL_LOG_NAME_LEN	512
#define TRX_SYS_MYSQL_LOG_MAGIC_N	873422344

/* The offset of the MySQL replication info in the trx system header;
this contains the same fields as TRX_SYS_MYSQL_LOG_INFO below */
#define TRX_SYS_MYSQL_MASTER_LOG_INFO	(UNIV_PAGE_SIZE - 2000)

/* The offset of the MySQL binlog offset info in the trx system header */
#define TRX_SYS_MYSQL_LOG_INFO		(UNIV_PAGE_SIZE - 1000)
#define	TRX_SYS_MYSQL_LOG_MAGIC_N_FLD	0	/* magic number which shows
						if we have valid data in the
						MySQL binlog info; the value
						is ..._MAGIC_N if yes */
#define TRX_SYS_MYSQL_LOG_OFFSET_HIGH	4	/* high 4 bytes of the offset
						within that file */
#define TRX_SYS_MYSQL_LOG_OFFSET_LOW	8	/* low 4 bytes of the offset
						within that file */
#define TRX_SYS_MYSQL_LOG_NAME		12	/* MySQL log file name */

/* The offset of the doublewrite buffer header on the trx system header page */
#define TRX_SYS_DOUBLEWRITE		(UNIV_PAGE_SIZE - 200)
/*-------------------------------------------------------------*/
#define TRX_SYS_DOUBLEWRITE_FSEG 	0	/* fseg header of the fseg
						containing the doublewrite
						buffer */
#define TRX_SYS_DOUBLEWRITE_MAGIC 	FSEG_HEADER_SIZE
						/* 4-byte magic number which
						shows if we already have
						created the doublewrite
						buffer */
#define TRX_SYS_DOUBLEWRITE_BLOCK1	(4 + FSEG_HEADER_SIZE)
						/* page number of the
						first page in the first
						sequence of 64
						(= FSP_EXTENT_SIZE) consecutive
						pages in the doublewrite
						buffer */
#define TRX_SYS_DOUBLEWRITE_BLOCK2	(8 + FSEG_HEADER_SIZE)
						/* page number of the
						first page in the second
						sequence of 64 consecutive
						pages in the doublewrite
						buffer */
#define TRX_SYS_DOUBLEWRITE_REPEAT	12	/* we repeat the above 3
						numbers so that if the trx
						sys header is half-written
						to disk, we still may be able
						to recover the information */
#define TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED (24 + FSEG_HEADER_SIZE)
						/* If this is not yet set to
						.._N, we must reset the
						doublewrite buffer, because
						starting from 4.1.x the space
						id of a data page is stored to
					FIL_PAGE_ARCH_LOG_NO_OR_SPACE_NO */
/*-------------------------------------------------------------*/
#define TRX_SYS_DOUBLEWRITE_MAGIC_N	536853855
#define TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED_N 1783657386


#define TRX_SYS_DOUBLEWRITE_BLOCK_SIZE	FSP_EXTENT_SIZE	

/* Doublewrite control struct */
struct trx_doublewrite_struct{
	mutex_t	mutex;		/* mutex protecting the first_free field and
				write_buf */
	ulint	block1;		/* the page number of the first
				doublewrite block (64 pages) */
	ulint	block2;		/* page number of the second block */
	ulint	first_free;	/* first free position in write_buf measured
				in units of UNIV_PAGE_SIZE */
	byte*	write_buf; 	/* write buffer used in writing to the
				doublewrite buffer, aligned to an
				address divisible by UNIV_PAGE_SIZE
				(which is required by Windows aio) */
	byte*	write_buf_unaligned; /* pointer to write_buf, but unaligned */
	buf_block_t**
		buf_block_arr;	/* array to store pointers to the buffer
				blocks which have been cached to write_buf */
};

/* The transaction system central memory data structure; protected by the
kernel mutex */
struct trx_sys_struct{
	dulint		max_trx_id;	/* The smallest number not yet
					assigned as a transaction id or
					transaction number */
	UT_LIST_BASE_NODE_T(trx_t) trx_list;
					/* List of active and committed in
					memory transactions, sorted on trx id,
					biggest first */
	UT_LIST_BASE_NODE_T(trx_t) mysql_trx_list;
					/* List of transactions created
					for MySQL */
	UT_LIST_BASE_NODE_T(trx_rseg_t) rseg_list;
					/* List of rollback segment objects */
	trx_rseg_t*	latest_rseg;	/* Latest rollback segment in the
					round-robin assignment of rollback
					segments to transactions */
	trx_rseg_t*	rseg_array[TRX_SYS_N_RSEGS];
					/* Pointer array to rollback segments;
					NULL if slot not in use */
	ulint		rseg_history_len;/* Length of the TRX_RSEG_HISTORY
					list (update undo logs for committed
					transactions), protected by
					rseg->mutex */
	UT_LIST_BASE_NODE_T(read_view_t) view_list;
					/* List of read views sorted on trx no,
					biggest first */
};

/* When a trx id which is zero modulo this number (which must be a power of
two) is assigned, the field TRX_SYS_TRX_ID_STORE on the transaction system
page is updated */
#define TRX_SYS_TRX_ID_WRITE_MARGIN	256

#ifndef UNIV_NONINL
#include "trx0sys.ic"
#endif

#endif