trx0sys.h
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- /******************************************************
- Transaction system
- (c) 1996 Innobase Oy
- Created 3/26/1996 Heikki Tuuri
- *******************************************************/
- #ifndef trx0sys_h
- #define trx0sys_h
- #include "univ.i"
- #include "trx0types.h"
- #include "mtr0mtr.h"
- #include "mtr0log.h"
- #include "ut0byte.h"
- #include "mem0mem.h"
- #include "sync0sync.h"
- #include "ut0lst.h"
- #include "buf0buf.h"
- #include "fil0fil.h"
- #include "fut0lst.h"
- #include "fsp0fsp.h"
- #include "read0types.h"
- /* In a MySQL replication slave, in crash recovery we store the master log
- file name and position here. We have successfully got the updates to InnoDB
- up to this position. If .._pos is -1, it means no crash recovery was needed,
- or there was no master log position info inside InnoDB. */
- extern char trx_sys_mysql_master_log_name[];
- extern ib_longlong trx_sys_mysql_master_log_pos;
- /* If this MySQL server uses binary logging, after InnoDB has been inited
- and if it has done a crash recovery, we store the binlog file name and position
- here. If .._pos is -1, it means there was no binlog position info inside
- InnoDB. */
- extern char trx_sys_mysql_bin_log_name[];
- extern ib_longlong trx_sys_mysql_bin_log_pos;
- /* The transaction system */
- extern trx_sys_t* trx_sys;
- /* Doublewrite system */
- extern trx_doublewrite_t* trx_doublewrite;
- extern ibool trx_doublewrite_must_reset_space_ids;
- extern ibool trx_sys_multiple_tablespace_format;
- /********************************************************************
- Creates the doublewrite buffer to a new InnoDB installation. The header of the
- doublewrite buffer is placed on the trx system header page. */
- void
- trx_sys_create_doublewrite_buf(void);
- /*================================*/
- /********************************************************************
- At a database startup initializes the doublewrite buffer memory structure if
- we already have a doublewrite buffer created in the data files. If we are
- upgrading to an InnoDB version which supports multiple tablespaces, then this
- function performs the necessary update operations. If we are in a crash
- recovery, this function uses a possible doublewrite buffer to restore
- half-written pages in the data files. */
- void
- trx_sys_doublewrite_init_or_restore_pages(
- /*======================================*/
- ibool restore_corrupt_pages);
- /********************************************************************
- Marks the trx sys header when we have successfully upgraded to the >= 4.1.x
- multiple tablespace format. */
- void
- trx_sys_mark_upgraded_to_multiple_tablespaces(void);
- /*===============================================*/
- /********************************************************************
- Determines if a page number is located inside the doublewrite buffer. */
- ibool
- trx_doublewrite_page_inside(
- /*========================*/
- /* out: TRUE if the location is inside
- the two blocks of the doublewrite buffer */
- ulint page_no); /* in: page number */
- /*******************************************************************
- Checks if a page address is the trx sys header page. */
- UNIV_INLINE
- ibool
- trx_sys_hdr_page(
- /*=============*/
- /* out: TRUE if trx sys header page */
- ulint space, /* in: space */
- ulint page_no);/* in: page number */
- /*********************************************************************
- Creates and initializes the central memory structures for the transaction
- system. This is called when the database is started. */
- void
- trx_sys_init_at_db_start(void);
- /*==========================*/
- /*********************************************************************
- Creates and initializes the transaction system at the database creation. */
- void
- trx_sys_create(void);
- /*================*/
- /********************************************************************
- Looks for a free slot for a rollback segment in the trx system file copy. */
- ulint
- trx_sysf_rseg_find_free(
- /*====================*/
- /* out: slot index or ULINT_UNDEFINED
- if not found */
- mtr_t* mtr); /* in: mtr */
- /*******************************************************************
- Gets the pointer in the nth slot of the rseg array. */
- UNIV_INLINE
- trx_rseg_t*
- trx_sys_get_nth_rseg(
- /*=================*/
- /* out: pointer to rseg object, NULL if slot
- not in use */
- trx_sys_t* sys, /* in: trx system */
- ulint n); /* in: index of slot */
- /*******************************************************************
- Sets the pointer in the nth slot of the rseg array. */
- UNIV_INLINE
- void
- trx_sys_set_nth_rseg(
- /*=================*/
- trx_sys_t* sys, /* in: trx system */
- ulint n, /* in: index of slot */
- trx_rseg_t* rseg); /* in: pointer to rseg object, NULL if slot
- not in use */
- /**************************************************************************
- Gets a pointer to the transaction system file copy and x-locks its page. */
- UNIV_INLINE
- trx_sysf_t*
- trx_sysf_get(
- /*=========*/
- /* out: pointer to system file copy, page x-locked */
- mtr_t* mtr); /* in: mtr */
- /*********************************************************************
- Gets the space of the nth rollback segment slot in the trx system
- file copy. */
- UNIV_INLINE
- ulint
- trx_sysf_rseg_get_space(
- /*====================*/
- /* out: space id */
- trx_sysf_t* sys_header, /* in: trx sys file copy */
- ulint i, /* in: slot index == rseg id */
- mtr_t* mtr); /* in: mtr */
- /*********************************************************************
- Gets the page number of the nth rollback segment slot in the trx system
- file copy. */
- UNIV_INLINE
- ulint
- trx_sysf_rseg_get_page_no(
- /*======================*/
- /* out: page number, FIL_NULL
- if slot unused */
- trx_sysf_t* sys_header, /* in: trx sys file copy */
- ulint i, /* in: slot index == rseg id */
- mtr_t* mtr); /* in: mtr */
- /*********************************************************************
- Sets the space id of the nth rollback segment slot in the trx system
- file copy. */
- UNIV_INLINE
- void
- trx_sysf_rseg_set_space(
- /*====================*/
- trx_sysf_t* sys_header, /* in: trx sys file copy */
- ulint i, /* in: slot index == rseg id */
- ulint space, /* in: space id */
- mtr_t* mtr); /* in: mtr */
- /*********************************************************************
- Sets the page number of the nth rollback segment slot in the trx system
- file copy. */
- UNIV_INLINE
- void
- trx_sysf_rseg_set_page_no(
- /*======================*/
- trx_sysf_t* sys_header, /* in: trx sys file copy */
- ulint i, /* in: slot index == rseg id */
- ulint page_no, /* in: page number, FIL_NULL if
- the slot is reset to unused */
- mtr_t* mtr); /* in: mtr */
- /*********************************************************************
- Allocates a new transaction id. */
- UNIV_INLINE
- dulint
- trx_sys_get_new_trx_id(void);
- /*========================*/
- /* out: new, allocated trx id */
- /*********************************************************************
- Allocates a new transaction number. */
- UNIV_INLINE
- dulint
- trx_sys_get_new_trx_no(void);
- /*========================*/
- /* out: new, allocated trx number */
- /*********************************************************************
- Writes a trx id to an index page. In case that the id size changes in
- some future version, this function should be used instead of
- mach_write_... */
- UNIV_INLINE
- void
- trx_write_trx_id(
- /*=============*/
- byte* ptr, /* in: pointer to memory where written */
- dulint id); /* in: id */
- /*********************************************************************
- Reads a trx id from an index page. In case that the id size changes in
- some future version, this function should be used instead of
- mach_read_... */
- UNIV_INLINE
- dulint
- trx_read_trx_id(
- /*============*/
- /* out: id */
- byte* ptr); /* in: pointer to memory from where to read */
- /********************************************************************
- Looks for the trx handle with the given id in trx_list. */
- UNIV_INLINE
- 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