344
344
mtr_t* mtr); /*!< in: mtr */
345
345
/********************************************************************//**
346
346
Moves a page to the start of the buffer pool LRU list. This high-level
347
function can be used to prevent an important page from slipping out of
347
function can be used to prevent an important page from from slipping out of
348
348
the buffer pool. */
705
705
/*==========================*/
706
706
const buf_page_t* bpage) /*!< in: pointer to control block */
707
707
__attribute__((pure));
708
/*********************************************************************//**
709
Determine the approximate LRU list position of a block.
710
@return LRU list position */
713
buf_page_get_LRU_position(
714
/*======================*/
715
const buf_page_t* bpage) /*!< in: control block */
716
__attribute__((pure));
709
718
/*********************************************************************//**
710
719
Gets the mutex of a block.
805
814
buf_page_t* bpage, /*!< in/out: control block */
806
815
ibool old); /*!< in: old */
807
816
/*********************************************************************//**
808
Determine the time of first access of a block in the buffer pool.
809
@return ut_time_ms() at the time of first access, 0 if not accessed */
817
Determine if a block has been accessed in the buffer pool.
818
@return TRUE if accessed */
812
821
buf_page_is_accessed(
813
822
/*=================*/
814
823
const buf_page_t* bpage) /*!< in: control block */
815
__attribute__((nonnull, pure));
824
__attribute__((pure));
816
825
/*********************************************************************//**
817
826
Flag a block accessed. */
820
829
buf_page_set_accessed(
821
830
/*==================*/
822
831
buf_page_t* bpage, /*!< in/out: control block */
823
ulint time_ms) /*!< in: ut_time_ms() */
824
__attribute__((nonnull));
832
ibool accessed); /*!< in: accessed */
825
833
/*********************************************************************//**
826
834
Gets the buf_block_t handle of a buffered file block if an uncompressed
827
835
page frame exists, or NULL.
1007
1015
/*===============*/
1008
1016
ulint space, /*!< in: space id */
1009
1017
ulint offset);/*!< in: offset of the page within space */
1018
/*******************************************************************//**
1019
Increments the pool clock by one and returns its new value. Remember that
1020
in the 32 bit version the clock wraps around at 4 billion!
1021
@return new clock value */
1024
buf_pool_clock_tic(void);
1025
/*====================*/
1010
1026
/*********************************************************************//**
1011
1027
Gets the current length of the free list of buffer blocks.
1012
1028
@return length of the free list */
1046
1062
flushed to disk, this tells the
1048
1064
@see enum buf_flush */
1065
unsigned accessed:1; /*!< TRUE if the page has been accessed
1066
while in the buffer pool: read-ahead
1067
may read in pages which have not been
1068
accessed yet; a thread is allowed to
1069
read this for heuristic purposes
1070
without holding any mutex or latch */
1049
1071
unsigned io_fix:2; /*!< type of pending I/O operation;
1050
1072
also protected by buf_pool_mutex
1051
1073
@see enum buf_io_fix */
1052
unsigned buf_fix_count:25;/*!< count of how manyfold this block
1074
unsigned buf_fix_count:24;/*!< count of how manyfold this block
1053
1075
is currently bufferfixed */
1055
1077
#endif /* !UNIV_HOTBACKUP */
1079
1101
- BUF_BLOCK_FILE_PAGE: flush_list
1080
1102
- BUF_BLOCK_ZIP_DIRTY: flush_list
1081
1103
- BUF_BLOCK_ZIP_PAGE: zip_clean
1082
- BUF_BLOCK_ZIP_FREE: zip_free[]
1084
The contents of the list node
1085
is undefined if !in_flush_list
1086
&& state == BUF_BLOCK_FILE_PAGE,
1087
or if state is one of
1089
BUF_BLOCK_REMOVE_HASH or
1090
BUF_BLOCK_READY_IN_USE. */
1104
- BUF_BLOCK_ZIP_FREE: zip_free[] */
1092
1105
#ifdef UNIV_DEBUG
1093
1106
ibool in_flush_list; /*!< TRUE if in buf_pool->flush_list;
1094
1107
when buf_pool_mutex is free, the
1128
1141
#endif /* UNIV_DEBUG */
1129
1142
unsigned old:1; /*!< TRUE if the block is in the old
1130
blocks in buf_pool->LRU_old */
1131
unsigned freed_page_clock:31;/*!< the value of
1143
blocks in the LRU list */
1144
unsigned LRU_position:31;/*!< value which monotonically
1145
decreases (or may stay
1146
constant if old==TRUE) toward
1147
the end of the LRU list, if
1148
buf_pool->ulint_clock has not
1149
wrapped around: NOTE that this
1150
value can only be used in
1151
heuristic algorithms, because
1152
of the possibility of a
1154
unsigned freed_page_clock:32;/*!< the value of
1132
1155
buf_pool->freed_page_clock
1133
1156
when this block was the last
1134
1157
time put to the head of the
1136
1159
to read this for heuristic
1137
1160
purposes without holding any
1138
1161
mutex or latch */
1139
unsigned access_time:32; /*!< time of first access, or
1140
0 if the block was never accessed
1141
in the buffer pool */
1143
1163
# ifdef UNIV_DEBUG_FILE_ACCESSES
1144
1164
ibool file_page_was_freed;
1283
1303
#define BUF_POOL_ZIP_FOLD_BPAGE(b) BUF_POOL_ZIP_FOLD((buf_block_t*) (b))
1286
/** @brief The buffer pool statistics structure. */
1287
struct buf_pool_stat_struct{
1288
ulint n_page_gets; /*!< number of page gets performed;
1289
also successful searches through
1290
the adaptive hash index are
1291
counted as page gets; this field
1292
is NOT protected by the buffer
1294
ulint n_pages_read; /*!< number read operations */
1295
ulint n_pages_written;/*!< number write operations */
1296
ulint n_pages_created;/*!< number of pages created
1297
in the pool with no read */
1298
ulint n_ra_pages_read;/*!< number of pages read in
1299
as part of read ahead */
1300
ulint n_ra_pages_evicted;/*!< number of read ahead
1301
pages that are evicted without
1303
ulint n_pages_made_young; /*!< number of pages made young, in
1304
calls to buf_LRU_make_block_young() */
1305
ulint n_pages_not_made_young; /*!< number of pages not made
1306
young because the first access
1307
was not long enough ago, in
1308
buf_page_peek_if_too_old() */
1311
1306
/** @brief The buffer pool structure.
1313
1308
NOTE! The definition appears here only for other modules of this
1332
1327
ulint n_pend_reads; /*!< number of pending read operations */
1333
1328
ulint n_pend_unzip; /*!< number of pending decompressions */
1335
time_t last_printout_time;
1336
/*!< when buf_print_io was last time
1330
time_t last_printout_time; /*!< when buf_print was last time
1338
buf_pool_stat_t stat; /*!< current statistics */
1339
buf_pool_stat_t old_stat; /*!< old statistics */
1332
ulint n_pages_read; /*!< number read operations */
1333
ulint n_pages_written;/*!< number write operations */
1334
ulint n_pages_created;/*!< number of pages created
1335
in the pool with no read */
1336
ulint n_page_gets; /*!< number of page gets performed;
1337
also successful searches through
1338
the adaptive hash index are
1339
counted as page gets; this field
1340
is NOT protected by the buffer
1342
ulint n_page_gets_old;/*!< n_page_gets when buf_print was
1343
last time called: used to calculate
1345
ulint n_pages_read_old;/*!< n_pages_read when buf_print was
1347
ulint n_pages_written_old;/*!< number write operations */
1348
ulint n_pages_created_old;/*!< number of pages created in
1349
the pool with no read */
1343
1351
/** @name Page flushing algorithm fields */
1347
1354
UT_LIST_BASE_NODE_T(buf_page_t) flush_list;
1357
1364
/*!< this is in the set state
1358
1365
when there is no flush batch
1359
1366
of the given type running */
1367
ulint ulint_clock; /*!< a sequence number used to count
1368
time. NOTE! This counter wraps
1369
around at 4 billion (if ulint ==
1360
1371
ulint freed_page_clock;/*!< a sequence number used
1361
1372
to count the number of buffer
1362
1373
blocks removed from the end of
1381
1392
UT_LIST_BASE_NODE_T(buf_page_t) LRU;
1382
1393
/*!< base node of the LRU list */
1383
buf_page_t* LRU_old; /*!< pointer to the about
1384
buf_LRU_old_ratio/BUF_LRU_OLD_RATIO_DIV
1385
oldest blocks in the LRU list;
1386
NULL if LRU length less than
1387
BUF_LRU_OLD_MIN_LEN;
1394
buf_page_t* LRU_old; /*!< pointer to the about 3/8 oldest
1395
blocks in the LRU list; NULL if LRU
1396
length less than BUF_LRU_OLD_MIN_LEN;
1388
1397
NOTE: when LRU_old != NULL, its length
1389
1398
should always equal LRU_old_len */
1390
1399
ulint LRU_old_len; /*!< length of the LRU list from
1391
1400
the block to which LRU_old points
1392
1401
onward, including that block;
1393
1402
see buf0lru.c for the restrictions
1394
on this value; 0 if LRU_old == NULL;
1403
on this value; not defined if
1395
1405
NOTE: LRU_old_len must be adjusted
1396
1406
whenever LRU_old shrinks or grows! */
added
removed
plugin/innobase/include/buf0buf.h
