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|
/*****************************************************************************
Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2017, MariaDB Corporation. All Rights Reserved.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file include/buf0buf.h
The database buffer pool high-level routines
Created 11/5/1995 Heikki Tuuri
*******************************************************/
#ifndef buf0buf_h
#define buf0buf_h
#include "univ.i"
#include "fil0fil.h"
#include "mtr0types.h"
#include "buf0types.h"
#include "hash0hash.h"
#include "ut0byte.h"
#include "page0types.h"
#ifndef UNIV_HOTBACKUP
#include "ut0rbt.h"
#include "os0proc.h"
#include "log0log.h"
/** @name Modes for buf_page_get_gen */
/* @{ */
#define BUF_GET 10 /*!< get always */
#define BUF_GET_IF_IN_POOL 11 /*!< get if in pool */
#define BUF_PEEK_IF_IN_POOL 12 /*!< get if in pool, do not make
the block young in the LRU list */
#define BUF_GET_NO_LATCH 14 /*!< get and bufferfix, but
set no latch; we have
separated this case, because
it is error-prone programming
not to set a latch, and it
should be used with care */
#define BUF_GET_IF_IN_POOL_OR_WATCH 15
/*!< Get the page only if it's in the
buffer pool, if not then set a watch
on the page. */
#define BUF_GET_POSSIBLY_FREED 16
/*!< Like BUF_GET, but do not mind
if the file page has been freed. */
/* @} */
/** @name Modes for buf_page_get_known_nowait */
/* @{ */
#define BUF_MAKE_YOUNG 51 /*!< Move the block to the
start of the LRU list if there
is a danger that the block
would drift out of the buffer
pool*/
#define BUF_KEEP_OLD 52 /*!< Preserve the current LRU
position of the block. */
/* @} */
#define MAX_BUFFER_POOLS_BITS 6 /*!< Number of bits to representing
a buffer pool ID */
#define MAX_BUFFER_POOLS (1 << MAX_BUFFER_POOLS_BITS)
/*!< The maximum number of buffer
pools that can be defined */
#define BUF_POOL_WATCH_SIZE (srv_n_purge_threads + 1)
/*!< Maximum number of concurrent
buffer pool watches */
#define MAX_PAGE_HASH_LOCKS 1024 /*!< The maximum number of
page_hash locks */
extern buf_pool_t* buf_pool_ptr; /*!< The buffer pools
of the database */
#ifdef UNIV_DEBUG
extern ibool buf_debug_prints;/*!< If this is set TRUE, the program
prints info whenever read or flush
occurs */
#endif /* UNIV_DEBUG */
extern ulint srv_buf_pool_instances;
extern ulint srv_buf_pool_curr_size;
#else /* !UNIV_HOTBACKUP */
extern buf_block_t* back_block1; /*!< first block, for --apply-log */
extern buf_block_t* back_block2; /*!< second block, for page reorganize */
#endif /* !UNIV_HOTBACKUP */
/** @brief States of a control block
@see buf_page_t
The enumeration values must be 0..7. */
enum buf_page_state {
BUF_BLOCK_POOL_WATCH, /*!< a sentinel for the buffer pool
watch, element of buf_pool->watch[] */
BUF_BLOCK_ZIP_PAGE, /*!< contains a clean
compressed page */
BUF_BLOCK_ZIP_DIRTY, /*!< contains a compressed
page that is in the
buf_pool->flush_list */
BUF_BLOCK_NOT_USED, /*!< is in the free list;
must be after the BUF_BLOCK_ZIP_
constants for compressed-only pages
@see buf_block_state_valid() */
BUF_BLOCK_READY_FOR_USE, /*!< when buf_LRU_get_free_block
returns a block, it is in this state */
BUF_BLOCK_FILE_PAGE, /*!< contains a buffered file page */
BUF_BLOCK_MEMORY, /*!< contains some main memory
object */
BUF_BLOCK_REMOVE_HASH /*!< hash index should be removed
before putting to the free list */
};
/** This structure defines information we will fetch from each buffer pool. It
will be used to print table IO stats */
struct buf_pool_info_t{
/* General buffer pool info */
ulint pool_unique_id; /*!< Buffer Pool ID */
ulint pool_size; /*!< Buffer Pool size in pages */
ulint pool_size_bytes;
ulint lru_len; /*!< Length of buf_pool->LRU */
ulint old_lru_len; /*!< buf_pool->LRU_old_len */
ulint free_list_len; /*!< Length of buf_pool->free list */
ulint flush_list_len; /*!< Length of buf_pool->flush_list */
ulint n_pend_unzip; /*!< buf_pool->n_pend_unzip, pages
pending decompress */
ulint n_pend_reads; /*!< buf_pool->n_pend_reads, pages
pending read */
ulint n_pending_flush_lru; /*!< Pages pending flush in LRU */
ulint n_pending_flush_single_page;/*!< Pages pending to be
flushed as part of single page
flushes issued by various user
threads */
ulint n_pending_flush_list; /*!< Pages pending flush in FLUSH
LIST */
ulint n_pages_made_young; /*!< number of pages made young */
ulint n_pages_not_made_young; /*!< number of pages not made young */
ulint n_pages_read; /*!< buf_pool->n_pages_read */
ulint n_pages_created; /*!< buf_pool->n_pages_created */
ulint n_pages_written; /*!< buf_pool->n_pages_written */
ulint n_page_gets; /*!< buf_pool->n_page_gets */
ulint n_ra_pages_read_rnd; /*!< buf_pool->n_ra_pages_read_rnd,
number of pages readahead */
ulint n_ra_pages_read; /*!< buf_pool->n_ra_pages_read, number
of pages readahead */
ulint n_ra_pages_evicted; /*!< buf_pool->n_ra_pages_evicted,
number of readahead pages evicted
without access */
ulint n_page_get_delta; /*!< num of buffer pool page gets since
last printout */
/* Buffer pool access stats */
double page_made_young_rate; /*!< page made young rate in pages
per second */
double page_not_made_young_rate;/*!< page not made young rate
in pages per second */
double pages_read_rate; /*!< num of pages read per second */
double pages_created_rate; /*!< num of pages create per second */
double pages_written_rate; /*!< num of pages written per second */
ulint page_read_delta; /*!< num of pages read since last
printout */
ulint young_making_delta; /*!< num of pages made young since
last printout */
ulint not_young_making_delta; /*!< num of pages not make young since
last printout */
/* Statistics about read ahead algorithm. */
double pages_readahead_rnd_rate;/*!< random readahead rate in pages per
second */
double pages_readahead_rate; /*!< readahead rate in pages per
second */
double pages_evicted_rate; /*!< rate of readahead page evicted
without access, in pages per second */
/* Stats about LRU eviction */
ulint unzip_lru_len; /*!< length of buf_pool->unzip_LRU
list */
/* Counters for LRU policy */
ulint io_sum; /*!< buf_LRU_stat_sum.io */
ulint io_cur; /*!< buf_LRU_stat_cur.io, num of IO
for current interval */
ulint unzip_sum; /*!< buf_LRU_stat_sum.unzip */
ulint unzip_cur; /*!< buf_LRU_stat_cur.unzip, num
pages decompressed in current
interval */
};
/** The occupied bytes of lists in all buffer pools */
struct buf_pools_list_size_t {
ulint LRU_bytes; /*!< LRU size in bytes */
ulint unzip_LRU_bytes; /*!< unzip_LRU size in bytes */
ulint flush_list_bytes; /*!< flush_list size in bytes */
};
#ifndef UNIV_HOTBACKUP
/********************************************************************//**
Creates the buffer pool.
@return DB_SUCCESS if success, DB_ERROR if not enough memory or error */
UNIV_INTERN
dberr_t
buf_pool_init(
/*=========*/
ulint size, /*!< in: Size of the total pool in bytes */
ulint n_instances); /*!< in: Number of instances */
/********************************************************************//**
Frees the buffer pool at shutdown. This must not be invoked before
freeing all mutexes. */
UNIV_INTERN
void
buf_pool_free(
/*==========*/
ulint n_instances); /*!< in: numbere of instances to free */
/********************************************************************//**
Clears the adaptive hash index on all pages in the buffer pool. */
UNIV_INTERN
void
buf_pool_clear_hash_index(void);
/*===========================*/
/********************************************************************//**
Relocate a buffer control block. Relocates the block on the LRU list
and in buf_pool->page_hash. Does not relocate bpage->list.
The caller must take care of relocating bpage->list. */
UNIV_INTERN
void
buf_relocate(
/*=========*/
buf_page_t* bpage, /*!< in/out: control block being relocated;
buf_page_get_state(bpage) must be
BUF_BLOCK_ZIP_DIRTY or BUF_BLOCK_ZIP_PAGE */
buf_page_t* dpage); /*!< in/out: destination control block */
/*********************************************************************//**
Gets the current size of buffer buf_pool in bytes.
@return size in bytes */
UNIV_INLINE
ulint
buf_pool_get_curr_size(void);
/*========================*/
/*********************************************************************//**
Gets the current size of buffer buf_pool in frames.
@return size in pages */
UNIV_INLINE
ulint
buf_pool_get_n_pages(void);
/*=======================*/
/********************************************************************//**
Gets the smallest oldest_modification lsn for any page in the pool. Returns
zero if all modified pages have been flushed to disk.
@return oldest modification in pool, zero if none */
UNIV_INTERN
lsn_t
buf_pool_get_oldest_modification(void);
/*==================================*/
/********************************************************************//**
Gets the smallest oldest_modification lsn for any page in the pool. Returns
zero if all modified pages have been flushed to disk.
@return oldest modification in pool, zero if none */
UNIV_INTERN
lsn_t
buf_pool_get_oldest_modification_peek(void);
/*=======================================*/
/********************************************************************//**
Allocates a buf_page_t descriptor. This function must succeed. In case
of failure we assert in this function. */
UNIV_INLINE
buf_page_t*
buf_page_alloc_descriptor(void)
/*===========================*/
MY_ATTRIBUTE((malloc));
/********************************************************************//**
Free a buf_page_t descriptor. */
UNIV_INLINE
void
buf_page_free_descriptor(
/*=====================*/
buf_page_t* bpage) /*!< in: bpage descriptor to free. */
MY_ATTRIBUTE((nonnull));
/********************************************************************//**
Allocates a buffer block.
@return own: the allocated block, in state BUF_BLOCK_MEMORY */
UNIV_INTERN
buf_block_t*
buf_block_alloc(
/*============*/
buf_pool_t* buf_pool); /*!< in: buffer pool instance,
or NULL for round-robin selection
of the buffer pool */
/********************************************************************//**
Frees a buffer block which does not contain a file page. */
UNIV_INLINE
void
buf_block_free(
/*===========*/
buf_block_t* block); /*!< in, own: block to be freed */
#endif /* !UNIV_HOTBACKUP */
/*********************************************************************//**
Copies contents of a buffer frame to a given buffer.
@return buf */
UNIV_INLINE
byte*
buf_frame_copy(
/*===========*/
byte* buf, /*!< in: buffer to copy to */
const buf_frame_t* frame); /*!< in: buffer frame */
#ifndef UNIV_HOTBACKUP
/**************************************************************//**
NOTE! The following macros should be used instead of buf_page_get_gen,
to improve debugging. Only values RW_S_LATCH and RW_X_LATCH are allowed
in LA! */
#define buf_page_get(SP, ZS, OF, LA, MTR) buf_page_get_gen(\
SP, ZS, OF, LA, NULL,\
BUF_GET, __FILE__, __LINE__, MTR)
/**************************************************************//**
Use these macros to bufferfix a page with no latching. Remember not to
read the contents of the page unless you know it is safe. Do not modify
the contents of the page! We have separated this case, because it is
error-prone programming not to set a latch, and it should be used
with care. */
#define buf_page_get_with_no_latch(SP, ZS, OF, MTR) buf_page_get_gen(\
SP, ZS, OF, RW_NO_LATCH, NULL,\
BUF_GET_NO_LATCH, __FILE__, __LINE__, MTR)
/********************************************************************//**
This is the general function used to get optimistic access to a database
page.
@return TRUE if success */
UNIV_INTERN
ibool
buf_page_optimistic_get(
/*====================*/
ulint rw_latch,/*!< in: RW_S_LATCH, RW_X_LATCH */
buf_block_t* block, /*!< in: guessed block */
ib_uint64_t modify_clock,/*!< in: modify clock value */
const char* file, /*!< in: file name */
ulint line, /*!< in: line where called */
mtr_t* mtr); /*!< in: mini-transaction */
/********************************************************************//**
This is used to get access to a known database page, when no waiting can be
done.
@return TRUE if success */
UNIV_INTERN
ibool
buf_page_get_known_nowait(
/*======================*/
ulint rw_latch,/*!< in: RW_S_LATCH, RW_X_LATCH */
buf_block_t* block, /*!< in: the known page */
ulint mode, /*!< in: BUF_MAKE_YOUNG or BUF_KEEP_OLD */
const char* file, /*!< in: file name */
ulint line, /*!< in: line where called */
mtr_t* mtr); /*!< in: mini-transaction */
/*******************************************************************//**
Given a tablespace id and page number tries to get that page. If the
page is not in the buffer pool it is not loaded and NULL is returned.
Suitable for using when holding the lock_sys_t::mutex. */
UNIV_INTERN
const buf_block_t*
buf_page_try_get_func(
/*==================*/
ulint space_id,/*!< in: tablespace id */
ulint page_no,/*!< in: page number */
const char* file, /*!< in: file name */
ulint line, /*!< in: line where called */
mtr_t* mtr); /*!< in: mini-transaction */
/** Tries to get a page. If the page is not in the buffer pool it is
not loaded. Suitable for using when holding the lock_sys_t::mutex.
@param space_id in: tablespace id
@param page_no in: page number
@param mtr in: mini-transaction
@return the page if in buffer pool, NULL if not */
#define buf_page_try_get(space_id, page_no, mtr) \
buf_page_try_get_func(space_id, page_no, __FILE__, __LINE__, mtr);
/********************************************************************//**
Get read access to a compressed page (usually of type
FIL_PAGE_TYPE_ZBLOB or FIL_PAGE_TYPE_ZBLOB2).
The page must be released with buf_page_release_zip().
NOTE: the page is not protected by any latch. Mutual exclusion has to
be implemented at a higher level. In other words, all possible
accesses to a given page through this function must be protected by
the same set of mutexes or latches.
@return pointer to the block, or NULL if not compressed */
UNIV_INTERN
buf_page_t*
buf_page_get_zip(
/*=============*/
ulint space, /*!< in: space id */
ulint zip_size,/*!< in: compressed page size */
ulint offset);/*!< in: page number */
/********************************************************************//**
This is the general function used to get access to a database page.
@return pointer to the block or NULL */
UNIV_INTERN
buf_block_t*
buf_page_get_gen(
/*=============*/
ulint space, /*!< in: space id */
ulint zip_size,/*!< in: compressed page size in bytes
or 0 for uncompressed pages */
ulint offset, /*!< in: page number */
ulint rw_latch,/*!< in: RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH */
buf_block_t* guess, /*!< in: guessed block or NULL */
ulint mode, /*!< in: BUF_GET, BUF_GET_IF_IN_POOL,
BUF_PEEK_IF_IN_POOL, BUF_GET_NO_LATCH or
BUF_GET_IF_IN_POOL_OR_WATCH */
const char* file, /*!< in: file name */
ulint line, /*!< in: line where called */
mtr_t* mtr); /*!< in: mini-transaction */
/********************************************************************//**
Initializes a page to the buffer buf_pool. The page is usually not read
from a file even if it cannot be found in the buffer buf_pool. This is one
of the functions which perform to a block a state transition NOT_USED =>
FILE_PAGE (the other is buf_page_get_gen).
@return pointer to the block, page bufferfixed */
UNIV_INTERN
buf_block_t*
buf_page_create(
/*============*/
ulint space, /*!< in: space id */
ulint offset, /*!< in: offset of the page within space in units of
a page */
ulint zip_size,/*!< in: compressed page size, or 0 */
mtr_t* mtr); /*!< in: mini-transaction handle */
#else /* !UNIV_HOTBACKUP */
/********************************************************************//**
Inits a page to the buffer buf_pool, for use in mysqlbackup --restore. */
UNIV_INTERN
void
buf_page_init_for_backup_restore(
/*=============================*/
ulint space, /*!< in: space id */
ulint offset, /*!< in: offset of the page within space
in units of a page */
ulint zip_size,/*!< in: compressed page size in bytes
or 0 for uncompressed pages */
buf_block_t* block); /*!< in: block to init */
#endif /* !UNIV_HOTBACKUP */
#ifndef UNIV_HOTBACKUP
/********************************************************************//**
Releases a compressed-only page acquired with buf_page_get_zip(). */
UNIV_INLINE
void
buf_page_release_zip(
/*=================*/
buf_page_t* bpage); /*!< in: buffer block */
/********************************************************************//**
Decrements the bufferfix count of a buffer control block and releases
a latch, if specified. */
UNIV_INLINE
void
buf_page_release(
/*=============*/
buf_block_t* block, /*!< in: buffer block */
ulint rw_latch); /*!< in: RW_S_LATCH, RW_X_LATCH,
RW_NO_LATCH */
/********************************************************************//**
Moves a page to the start of the buffer pool LRU list. This high-level
function can be used to prevent an important page from slipping out of
the buffer pool. */
UNIV_INTERN
void
buf_page_make_young(
/*================*/
buf_page_t* bpage); /*!< in: buffer block of a file page */
/********************************************************************//**
Returns TRUE if the page can be found in the buffer pool hash table.
NOTE that it is possible that the page is not yet read from disk,
though.
@return TRUE if found in the page hash table */
UNIV_INLINE
ibool
buf_page_peek(
/*==========*/
ulint space, /*!< in: space id */
ulint offset);/*!< in: page number */
#if defined UNIV_DEBUG_FILE_ACCESSES || defined UNIV_DEBUG
/********************************************************************//**
Sets file_page_was_freed TRUE if the page is found in the buffer pool.
This function should be called when we free a file page and want the
debug version to check that it is not accessed any more unless
reallocated.
@return control block if found in page hash table, otherwise NULL */
UNIV_INTERN
buf_page_t*
buf_page_set_file_page_was_freed(
/*=============================*/
ulint space, /*!< in: space id */
ulint offset);/*!< in: page number */
/********************************************************************//**
Sets file_page_was_freed FALSE if the page is found in the buffer pool.
This function should be called when we free a file page and want the
debug version to check that it is not accessed any more unless
reallocated.
@return control block if found in page hash table, otherwise NULL */
UNIV_INTERN
buf_page_t*
buf_page_reset_file_page_was_freed(
/*===============================*/
ulint space, /*!< in: space id */
ulint offset); /*!< in: page number */
#endif /* UNIV_DEBUG_FILE_ACCESSES || UNIV_DEBUG */
/********************************************************************//**
Reads the freed_page_clock of a buffer block.
@return freed_page_clock */
UNIV_INLINE
ulint
buf_page_get_freed_page_clock(
/*==========================*/
const buf_page_t* bpage) /*!< in: block */
MY_ATTRIBUTE((pure));
/********************************************************************//**
Reads the freed_page_clock of a buffer block.
@return freed_page_clock */
UNIV_INLINE
ulint
buf_block_get_freed_page_clock(
/*===========================*/
const buf_block_t* block) /*!< in: block */
MY_ATTRIBUTE((pure));
/********************************************************************//**
Tells if a block is still close enough to the MRU end of the LRU list
meaning that it is not in danger of getting evicted and also implying
that it has been accessed recently.
Note that this is for heuristics only and does not reserve buffer pool
mutex.
@return TRUE if block is close to MRU end of LRU */
UNIV_INLINE
ibool
buf_page_peek_if_young(
/*===================*/
const buf_page_t* bpage); /*!< in: block */
/********************************************************************//**
Recommends a move of a block to the start of the LRU list if there is danger
of dropping from the buffer pool. NOTE: does not reserve the buffer pool
mutex.
@return TRUE if should be made younger */
UNIV_INLINE
ibool
buf_page_peek_if_too_old(
/*=====================*/
const buf_page_t* bpage); /*!< in: block to make younger */
/********************************************************************//**
Gets the youngest modification log sequence number for a frame.
Returns zero if not file page or no modification occurred yet.
@return newest modification to page */
UNIV_INLINE
lsn_t
buf_page_get_newest_modification(
/*=============================*/
const buf_page_t* bpage); /*!< in: block containing the
page frame */
/********************************************************************//**
Increments the modify clock of a frame by 1. The caller must (1) own the
LRU list mutex and block bufferfix count has to be zero, (2) or own an x-lock
on the block. */
UNIV_INLINE
void
buf_block_modify_clock_inc(
/*=======================*/
buf_block_t* block); /*!< in: block */
/********************************************************************//**
Returns the value of the modify clock. The caller must have an s-lock
or x-lock on the block.
@return value */
UNIV_INLINE
ib_uint64_t
buf_block_get_modify_clock(
/*=======================*/
buf_block_t* block); /*!< in: block */
/*******************************************************************//**
Increments the bufferfix count. */
UNIV_INLINE
void
buf_block_buf_fix_inc_func(
/*=======================*/
# ifdef UNIV_SYNC_DEBUG
const char* file, /*!< in: file name */
ulint line, /*!< in: line */
# endif /* UNIV_SYNC_DEBUG */
buf_block_t* block) /*!< in/out: block to bufferfix */
MY_ATTRIBUTE((nonnull));
/*******************************************************************//**
Increments the bufferfix count. */
UNIV_INLINE
void
buf_block_fix(
/*===========*/
buf_block_t* block); /*!< in/out: block to bufferfix */
/*******************************************************************//**
Increments the bufferfix count. */
UNIV_INLINE
void
buf_block_unfix(
/*===========*/
buf_block_t* block); /*!< in/out: block to bufferfix */
# ifdef UNIV_SYNC_DEBUG
/** Increments the bufferfix count.
@param b in/out: block to bufferfix
@param f in: file name where requested
@param l in: line number where requested */
# define buf_block_buf_fix_inc(b,f,l) buf_block_buf_fix_inc_func(f,l,b)
# else /* UNIV_SYNC_DEBUG */
/** Increments the bufferfix count.
@param b in/out: block to bufferfix
@param f in: file name where requested
@param l in: line number where requested */
# define buf_block_buf_fix_inc(b,f,l) buf_block_buf_fix_inc_func(b)
# endif /* UNIV_SYNC_DEBUG */
#else /* !UNIV_HOTBACKUP */
# define buf_block_modify_clock_inc(block) ((void) 0)
#endif /* !UNIV_HOTBACKUP */
/********************************************************************//**
Checks if a page is corrupt.
@return TRUE if corrupted */
UNIV_INTERN
ibool
buf_page_is_corrupted(
/*==================*/
bool check_lsn, /*!< in: true if we need to check the
and complain about the LSN */
const byte* read_buf, /*!< in: a database page */
ulint zip_size) /*!< in: size of compressed page;
0 for uncompressed pages */
MY_ATTRIBUTE((nonnull, warn_unused_result));
/********************************************************************//**
Checks if a page is all zeroes.
@return TRUE if the page is all zeroes */
bool
buf_page_is_zeroes(
/*===============*/
const byte* read_buf, /*!< in: a database page */
const ulint zip_size); /*!< in: size of compressed page;
0 for uncompressed pages */
#ifndef UNIV_HOTBACKUP
/**********************************************************************//**
Gets the space id, page offset, and byte offset within page of a
pointer pointing to a buffer frame containing a file page. */
UNIV_INLINE
void
buf_ptr_get_fsp_addr(
/*=================*/
const void* ptr, /*!< in: pointer to a buffer frame */
ulint* space, /*!< out: space id */
fil_addr_t* addr); /*!< out: page offset and byte offset */
/**********************************************************************//**
Gets the hash value of a block. This can be used in searches in the
lock hash table.
@return lock hash value */
UNIV_INLINE
ulint
buf_block_get_lock_hash_val(
/*========================*/
const buf_block_t* block) /*!< in: block */
MY_ATTRIBUTE((pure));
#ifdef UNIV_DEBUG
/*********************************************************************//**
Finds a block in the buffer pool that points to a
given compressed page.
@return buffer block pointing to the compressed page, or NULL */
UNIV_INTERN
buf_block_t*
buf_pool_contains_zip(
/*==================*/
buf_pool_t* buf_pool, /*!< in: buffer pool instance */
const void* data); /*!< in: pointer to compressed page */
#endif /* UNIV_DEBUG */
/***********************************************************************
FIXME_FTS: Gets the frame the pointer is pointing to. */
UNIV_INLINE
buf_frame_t*
buf_frame_align(
/*============*/
/* out: pointer to frame */
byte* ptr); /* in: pointer to a frame */
#if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
/*********************************************************************//**
Validates the buffer pool data structure.
@return TRUE */
UNIV_INTERN
ibool
buf_validate(void);
/*==============*/
#endif /* UNIV_DEBUG || UNIV_BUF_DEBUG */
#if defined UNIV_DEBUG_PRINT || defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
/*********************************************************************//**
Prints info of the buffer pool data structure. */
UNIV_INTERN
void
buf_print(void);
/*============*/
#endif /* UNIV_DEBUG_PRINT || UNIV_DEBUG || UNIV_BUF_DEBUG */
#endif /* !UNIV_HOTBACKUP */
enum buf_page_print_flags {
/** Do not crash at the end of buf_page_print(). */
BUF_PAGE_PRINT_NO_CRASH = 1,
/** Do not print the full page dump. */
BUF_PAGE_PRINT_NO_FULL = 2
};
/********************************************************************//**
Prints a page to stderr. */
UNIV_INTERN
void
buf_page_print(
/*===========*/
const byte* read_buf, /*!< in: a database page */
ulint zip_size, /*!< in: compressed page size, or
0 for uncompressed pages */
ulint flags) /*!< in: 0 or
BUF_PAGE_PRINT_NO_CRASH or
BUF_PAGE_PRINT_NO_FULL */
UNIV_COLD;
/********************************************************************//**
Decompress a block.
@return TRUE if successful */
UNIV_INTERN
ibool
buf_zip_decompress(
/*===============*/
buf_block_t* block, /*!< in/out: block */
ibool check); /*!< in: TRUE=verify the page checksum */
#ifndef UNIV_HOTBACKUP
#ifdef UNIV_DEBUG
/*********************************************************************//**
Returns the number of latched pages in the buffer pool.
@return number of latched pages */
UNIV_INTERN
ulint
buf_get_latched_pages_number(void);
/*==============================*/
#endif /* UNIV_DEBUG */
/*********************************************************************//**
Returns the number of pending buf pool read ios.
@return number of pending read I/O operations */
UNIV_INTERN
ulint
buf_get_n_pending_read_ios(void);
/*============================*/
/*********************************************************************//**
Prints info of the buffer i/o. */
UNIV_INTERN
void
buf_print_io(
/*=========*/
FILE* file); /*!< in: file where to print */
/*******************************************************************//**
Collect buffer pool stats information for a buffer pool. Also
record aggregated stats if there are more than one buffer pool
in the server */
UNIV_INTERN
void
buf_stats_get_pool_info(
/*====================*/
buf_pool_t* buf_pool, /*!< in: buffer pool */
ulint pool_id, /*!< in: buffer pool ID */
buf_pool_info_t* all_pool_info); /*!< in/out: buffer pool info
to fill */
/*********************************************************************//**
Returns the ratio in percents of modified pages in the buffer pool /
database pages in the buffer pool.
@return modified page percentage ratio */
UNIV_INTERN
double
buf_get_modified_ratio_pct(void);
/*============================*/
/**********************************************************************//**
Refreshes the statistics used to print per-second averages. */
UNIV_INTERN
void
buf_refresh_io_stats(
/*=================*/
buf_pool_t* buf_pool); /*!< buffer pool instance */
/**********************************************************************//**
Refreshes the statistics used to print per-second averages. */
UNIV_INTERN
void
buf_refresh_io_stats_all(void);
/*=================*/
/*********************************************************************//**
Asserts that all file pages in the buffer are in a replaceable state.
@return TRUE */
UNIV_INTERN
ibool
buf_all_freed(void);
/*===============*/
/*********************************************************************//**
Checks that there currently are no pending i/o-operations for the buffer
pool.
@return number of pending i/o operations */
UNIV_INTERN
ulint
buf_pool_check_no_pending_io(void);
/*==============================*/
/*********************************************************************//**
Invalidates the file pages in the buffer pool when an archive recovery is
completed. All the file pages buffered must be in a replaceable state when
this function is called: not latched and not modified. */
UNIV_INTERN
void
buf_pool_invalidate(void);
/*=====================*/
#endif /* !UNIV_HOTBACKUP */
/*========================================================================
--------------------------- LOWER LEVEL ROUTINES -------------------------
=========================================================================*/
#ifdef UNIV_SYNC_DEBUG
/*********************************************************************//**
Adds latch level info for the rw-lock protecting the buffer frame. This
should be called in the debug version after a successful latching of a
page if we know the latching order level of the acquired latch. */
UNIV_INLINE
void
buf_block_dbg_add_level(
/*====================*/
buf_block_t* block, /*!< in: buffer page
where we have acquired latch */
ulint level); /*!< in: latching order level */
#else /* UNIV_SYNC_DEBUG */
# define buf_block_dbg_add_level(block, level) /* nothing */
#endif /* UNIV_SYNC_DEBUG */
/*********************************************************************//**
Gets the state of a block.
@return state */
UNIV_INLINE
enum buf_page_state
buf_page_get_state(
/*===============*/
const buf_page_t* bpage); /*!< in: pointer to the control block */
/*********************************************************************//**
Gets the state of a block.
@return state */
UNIV_INLINE
enum buf_page_state
buf_block_get_state(
/*================*/
const buf_block_t* block) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Sets the state of a block. */
UNIV_INLINE
void
buf_page_set_state(
/*===============*/
buf_page_t* bpage, /*!< in/out: pointer to control block */
enum buf_page_state state); /*!< in: state */
/*********************************************************************//**
Sets the state of a block. */
UNIV_INLINE
void
buf_block_set_state(
/*================*/
buf_block_t* block, /*!< in/out: pointer to control block */
enum buf_page_state state); /*!< in: state */
/*********************************************************************//**
Determines if a block is mapped to a tablespace.
@return TRUE if mapped */
UNIV_INLINE
ibool
buf_page_in_file(
/*=============*/
const buf_page_t* bpage) /*!< in: pointer to control block */
MY_ATTRIBUTE((pure));
#ifndef UNIV_HOTBACKUP
/*********************************************************************//**
Determines if a block should be on unzip_LRU list.
@return TRUE if block belongs to unzip_LRU */
UNIV_INLINE
ibool
buf_page_belongs_to_unzip_LRU(
/*==========================*/
const buf_page_t* bpage) /*!< in: pointer to control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets the mutex of a block.
@return pointer to mutex protecting bpage */
UNIV_INLINE
ib_mutex_t*
buf_page_get_mutex(
/*===============*/
const buf_page_t* bpage) /*!< in: pointer to control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Get the flush type of a page.
@return flush type */
UNIV_INLINE
buf_flush_t
buf_page_get_flush_type(
/*====================*/
const buf_page_t* bpage) /*!< in: buffer page */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Set the flush type of a page. */
UNIV_INLINE
void
buf_page_set_flush_type(
/*====================*/
buf_page_t* bpage, /*!< in: buffer page */
buf_flush_t flush_type); /*!< in: flush type */
/*********************************************************************//**
Map a block to a file page. */
UNIV_INLINE
void
buf_block_set_file_page(
/*====================*/
buf_block_t* block, /*!< in/out: pointer to control block */
ulint space, /*!< in: tablespace id */
ulint page_no);/*!< in: page number */
/*********************************************************************//**
Gets the io_fix state of a block.
@return io_fix state */
UNIV_INLINE
enum buf_io_fix
buf_page_get_io_fix(
/*================*/
const buf_page_t* bpage) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets the io_fix state of a block.
@return io_fix state */
UNIV_INLINE
enum buf_io_fix
buf_block_get_io_fix(
/*================*/
const buf_block_t* block) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets the io_fix state of a block. Does not assert that the
buf_page_get_mutex() mutex is held, to be used in the cases where it is safe
not to hold it.
@return io_fix state */
UNIV_INLINE
enum buf_io_fix
buf_page_get_io_fix_unlocked(
/*=========================*/
const buf_page_t* bpage) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Sets the io_fix state of a block. */
UNIV_INLINE
void
buf_page_set_io_fix(
/*================*/
buf_page_t* bpage, /*!< in/out: control block */
enum buf_io_fix io_fix);/*!< in: io_fix state */
/*********************************************************************//**
Sets the io_fix state of a block. */
UNIV_INLINE
void
buf_block_set_io_fix(
/*=================*/
buf_block_t* block, /*!< in/out: control block */
enum buf_io_fix io_fix);/*!< in: io_fix state */
/*********************************************************************//**
Makes a block sticky. A sticky block implies that even after we release
the buf_pool->LRU_list_mutex and the block->mutex:
* it cannot be removed from the flush_list
* the block descriptor cannot be relocated
* it cannot be removed from the LRU list
Note that:
* the block can still change its position in the LRU list
* the next and previous pointers can change. */
UNIV_INLINE
void
buf_page_set_sticky(
/*================*/
buf_page_t* bpage); /*!< in/out: control block */
/*********************************************************************//**
Removes stickiness of a block. */
UNIV_INLINE
void
buf_page_unset_sticky(
/*==================*/
buf_page_t* bpage); /*!< in/out: control block */
/********************************************************************//**
Determine if a buffer block can be relocated in memory. The block
can be dirty, but it must not be I/O-fixed or bufferfixed. */
UNIV_INLINE
ibool
buf_page_can_relocate(
/*==================*/
const buf_page_t* bpage) /*!< control block being relocated */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Determine if a block has been flagged old.
@return TRUE if old */
UNIV_INLINE
ibool
buf_page_is_old(
/*============*/
const buf_page_t* bpage) /*!< in: control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Flag a block old. */
UNIV_INLINE
void
buf_page_set_old(
/*=============*/
buf_page_t* bpage, /*!< in/out: control block */
ibool old); /*!< in: old */
/*********************************************************************//**
Determine the time of first access of a block in the buffer pool.
@return ut_time_ms() at the time of first access, 0 if not accessed */
UNIV_INLINE
unsigned
buf_page_is_accessed(
/*=================*/
const buf_page_t* bpage) /*!< in: control block */
MY_ATTRIBUTE((nonnull, pure));
/*********************************************************************//**
Flag a block accessed. */
UNIV_INLINE
void
buf_page_set_accessed(
/*==================*/
buf_page_t* bpage) /*!< in/out: control block */
MY_ATTRIBUTE((nonnull));
/*********************************************************************//**
Gets the buf_block_t handle of a buffered file block if an uncompressed
page frame exists, or NULL. Note: even though bpage is not declared a
const we don't update its value. It is safe to make this pure.
@return control block, or NULL */
UNIV_INLINE
buf_block_t*
buf_page_get_block(
/*===============*/
buf_page_t* bpage) /*!< in: control block, or NULL */
MY_ATTRIBUTE((pure));
#endif /* !UNIV_HOTBACKUP */
#ifdef UNIV_DEBUG
/*********************************************************************//**
Gets a pointer to the memory frame of a block.
@return pointer to the frame */
UNIV_INLINE
buf_frame_t*
buf_block_get_frame(
/*================*/
const buf_block_t* block) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets a pointer to the memory frame of a block, where block is known not to be
NULL.
@return pointer to the frame */
UNIV_INLINE
buf_frame_t*
buf_nonnull_block_get_frame(
const buf_block_t* block) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
#else /* UNIV_DEBUG */
# define buf_block_get_frame(block) (block ? (block)->frame : 0)
# define buf_nonnull_block_get_frame(block) ((block)->frame)
#endif /* UNIV_DEBUG */
/*********************************************************************//**
Gets the space id of a block.
@return space id */
UNIV_INLINE
ulint
buf_page_get_space(
/*===============*/
const buf_page_t* bpage) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets the space id of a block.
@return space id */
UNIV_INLINE
ulint
buf_block_get_space(
/*================*/
const buf_block_t* block) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets the page number of a block.
@return page number */
UNIV_INLINE
ulint
buf_page_get_page_no(
/*=================*/
const buf_page_t* bpage) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets the page number of a block.
@return page number */
UNIV_INLINE
ulint
buf_block_get_page_no(
/*==================*/
const buf_block_t* block) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets the compressed page size of a block.
@return compressed page size, or 0 */
UNIV_INLINE
ulint
buf_page_get_zip_size(
/*==================*/
const buf_page_t* bpage) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets the compressed page size of a block.
@return compressed page size, or 0 */
UNIV_INLINE
ulint
buf_block_get_zip_size(
/*===================*/
const buf_block_t* block) /*!< in: pointer to the control block */
MY_ATTRIBUTE((pure));
/*********************************************************************//**
Gets the compressed page descriptor corresponding to an uncompressed page
if applicable. */
#define buf_block_get_page_zip(block) \
((block)->page.zip.data ? &(block)->page.zip : NULL)
#ifndef UNIV_HOTBACKUP
/*******************************************************************//**
Gets the block to whose frame the pointer is pointing to.
@return pointer to block, never NULL */
UNIV_INTERN
buf_block_t*
buf_block_align(
/*============*/
const byte* ptr); /*!< in: pointer to a frame */
/********************************************************************//**
Find out if a pointer belongs to a buf_block_t. It can be a pointer to
the buf_block_t itself or a member of it
@return TRUE if ptr belongs to a buf_block_t struct */
UNIV_INTERN
ibool
buf_pointer_is_block_field(
/*=======================*/
const void* ptr); /*!< in: pointer not
dereferenced */
/** Find out if a pointer corresponds to a buf_block_t::mutex.
@param m in: mutex candidate
@return TRUE if m is a buf_block_t::mutex */
#define buf_pool_is_block_mutex(m) \
buf_pointer_is_block_field((const void*)(m))
/** Find out if a pointer corresponds to a buf_block_t::lock.
@param l in: rw-lock candidate
@return TRUE if l is a buf_block_t::lock */
#define buf_pool_is_block_lock(l) \
buf_pointer_is_block_field((const void*)(l))
#if defined UNIV_DEBUG || defined UNIV_ZIP_DEBUG
/*********************************************************************//**
Gets the compressed page descriptor corresponding to an uncompressed page
if applicable.
@return compressed page descriptor, or NULL */
UNIV_INLINE
const page_zip_des_t*
buf_frame_get_page_zip(
/*===================*/
const byte* ptr); /*!< in: pointer to the page */
#endif /* UNIV_DEBUG || UNIV_ZIP_DEBUG */
/********************************************************************//**
Function which inits a page for read to the buffer buf_pool. If the page is
(1) already in buf_pool, or
(2) if we specify to read only ibuf pages and the page is not an ibuf page, or
(3) if the space is deleted or being deleted,
then this function does nothing.
Sets the io_fix flag to BUF_IO_READ and sets a non-recursive exclusive lock
on the buffer frame. The io-handler must take care that the flag is cleared
and the lock released later.
@return pointer to the block or NULL */
UNIV_INTERN
buf_page_t*
buf_page_init_for_read(
/*===================*/
dberr_t* err, /*!< out: DB_SUCCESS or DB_TABLESPACE_DELETED */
ulint mode, /*!< in: BUF_READ_IBUF_PAGES_ONLY, ... */
ulint space, /*!< in: space id */
ulint zip_size,/*!< in: compressed page size, or 0 */
ibool unzip, /*!< in: TRUE=request uncompressed page */
ib_int64_t tablespace_version,/*!< in: prevents reading from a wrong
version of the tablespace in case we have done
DISCARD + IMPORT */
ulint offset);/*!< in: page number */
/********************************************************************//**
Completes an asynchronous read or write request of a file page to or from
the buffer pool.
@return true if successful */
UNIV_INTERN
bool
buf_page_io_complete(
/*=================*/
buf_page_t* bpage); /*!< in: pointer to the block in question */
/********************************************************************//**
Calculates a folded value of a file page address to use in the page hash
table.
@return the folded value */
UNIV_INLINE
ulint
buf_page_address_fold(
/*==================*/
ulint space, /*!< in: space id */
ulint offset) /*!< in: offset of the page within space */
MY_ATTRIBUTE((const));
/********************************************************************//**
Calculates the index of a buffer pool to the buf_pool[] array.
@return the position of the buffer pool in buf_pool[] */
UNIV_INLINE
ulint
buf_pool_index(
/*===========*/
const buf_pool_t* buf_pool) /*!< in: buffer pool */
MY_ATTRIBUTE((nonnull, const));
/******************************************************************//**
Returns the buffer pool instance given a page instance
@return buf_pool */
UNIV_INLINE
buf_pool_t*
buf_pool_from_bpage(
/*================*/
const buf_page_t* bpage); /*!< in: buffer pool page */
/******************************************************************//**
Returns the buffer pool instance given a block instance
@return buf_pool */
UNIV_INLINE
buf_pool_t*
buf_pool_from_block(
/*================*/
const buf_block_t* block); /*!< in: block */
/******************************************************************//**
Returns the buffer pool instance given space and offset of page
@return buffer pool */
UNIV_INLINE
buf_pool_t*
buf_pool_get(
/*==========*/
ulint space, /*!< in: space id */
ulint offset);/*!< in: offset of the page within space */
/******************************************************************//**
Returns the buffer pool instance given its array index
@return buffer pool */
UNIV_INLINE
buf_pool_t*
buf_pool_from_array(
/*================*/
ulint index); /*!< in: array index to get
buffer pool instance from */
/******************************************************************//**
Returns the control block of a file page, NULL if not found.
@return block, NULL if not found */
UNIV_INLINE
buf_page_t*
buf_page_hash_get_low(
/*==================*/
buf_pool_t* buf_pool,/*!< buffer pool instance */
ulint space, /*!< in: space id */
ulint offset, /*!< in: offset of the page within space */
ulint fold); /*!< in: buf_page_address_fold(space, offset) */
/******************************************************************//**
Returns the control block of a file page, NULL if not found.
If the block is found and lock is not NULL then the appropriate
page_hash lock is acquired in the specified lock mode. Otherwise,
mode value is ignored. It is up to the caller to release the
lock. If the block is found and the lock is NULL then the page_hash
lock is released by this function.
@return block, NULL if not found, or watch sentinel (if watch is true) */
UNIV_INLINE
buf_page_t*
buf_page_hash_get_locked(
/*=====================*/
/*!< out: pointer to the bpage,
or NULL; if NULL, hash_lock
is also NULL. */
buf_pool_t* buf_pool, /*!< buffer pool instance */
ulint space, /*!< in: space id */
ulint offset, /*!< in: page number */
prio_rw_lock_t** lock, /*!< in/out: lock of the page
hash acquired if bpage is
found. NULL otherwise. If NULL
is passed then the hash_lock
is released by this function */
ulint lock_mode, /*!< in: RW_LOCK_EX or
RW_LOCK_SHARED. Ignored if
lock == NULL */
bool watch = false); /*!< in: if true, return watch
sentinel also. */
/******************************************************************//**
Returns the control block of a file page, NULL if not found.
If the block is found and lock is not NULL then the appropriate
page_hash lock is acquired in the specified lock mode. Otherwise,
mode value is ignored. It is up to the caller to release the
lock. If the block is found and the lock is NULL then the page_hash
lock is released by this function.
@return block, NULL if not found */
UNIV_INLINE
buf_block_t*
buf_block_hash_get_locked(
/*=====================*/
/*!< out: pointer to the bpage,
or NULL; if NULL, hash_lock
is also NULL. */
buf_pool_t* buf_pool, /*!< buffer pool instance */
ulint space, /*!< in: space id */
ulint offset, /*!< in: page number */
prio_rw_lock_t** lock, /*!< in/out: lock of the page
hash acquired if bpage is
found. NULL otherwise. If NULL
is passed then the hash_lock
is released by this function */
ulint lock_mode); /*!< in: RW_LOCK_EX or
RW_LOCK_SHARED. Ignored if
lock == NULL */
/* There are four different ways we can try to get a bpage or block
from the page hash:
1) Caller already holds the appropriate page hash lock: in the case call
buf_page_hash_get_low() function.
2) Caller wants to hold page hash lock in x-mode
3) Caller wants to hold page hash lock in s-mode
4) Caller doesn't want to hold page hash lock */
#define buf_page_hash_get_s_locked(b, s, o, l) \
buf_page_hash_get_locked(b, s, o, l, RW_LOCK_SHARED)
#define buf_page_hash_get_x_locked(b, s, o, l) \
buf_page_hash_get_locked(b, s, o, l, RW_LOCK_EX)
#define buf_page_hash_get(b, s, o) \
buf_page_hash_get_locked(b, s, o, NULL, 0)
#define buf_page_get_also_watch(b, s, o) \
buf_page_hash_get_locked(b, s, o, NULL, 0, true)
#define buf_block_hash_get_s_locked(b, s, o, l) \
buf_block_hash_get_locked(b, s, o, l, RW_LOCK_SHARED)
#define buf_block_hash_get_x_locked(b, s, o, l) \
buf_block_hash_get_locked(b, s, o, l, RW_LOCK_EX)
#define buf_block_hash_get(b, s, o) \
buf_block_hash_get_locked(b, s, o, NULL, 0)
/*********************************************************************//**
Gets the current length of the free list of buffer blocks.
@return length of the free list */
UNIV_INTERN
ulint
buf_get_free_list_len(void);
/*=======================*/
/********************************************************************//**
Determine if a block is a sentinel for a buffer pool watch.
@return TRUE if a sentinel for a buffer pool watch, FALSE if not */
UNIV_INTERN
ibool
buf_pool_watch_is_sentinel(
/*=======================*/
buf_pool_t* buf_pool, /*!< buffer pool instance */
const buf_page_t* bpage) /*!< in: block */
MY_ATTRIBUTE((nonnull, warn_unused_result));
/****************************************************************//**
Add watch for the given page to be read in. Caller must have
appropriate hash_lock for the bpage and hold the LRU list mutex to avoid a race
condition with buf_LRU_free_page inserting the same page into the page hash.
This function may release the hash_lock and reacquire it.
@return NULL if watch set, block if the page is in the buffer pool */
UNIV_INTERN
buf_page_t*
buf_pool_watch_set(
/*===============*/
ulint space, /*!< in: space id */
ulint offset, /*!< in: page number */
ulint fold) /*!< in: buf_page_address_fold(space, offset) */
MY_ATTRIBUTE((warn_unused_result));
/****************************************************************//**
Stop watching if the page has been read in.
buf_pool_watch_set(space,offset) must have returned NULL before. */
UNIV_INTERN
void
buf_pool_watch_unset(
/*=================*/
ulint space, /*!< in: space id */
ulint offset);/*!< in: page number */
/****************************************************************//**
Check if the page has been read in.
This may only be called after buf_pool_watch_set(space,offset)
has returned NULL and before invoking buf_pool_watch_unset(space,offset).
@return FALSE if the given page was not read in, TRUE if it was */
UNIV_INTERN
ibool
buf_pool_watch_occurred(
/*====================*/
ulint space, /*!< in: space id */
ulint offset) /*!< in: page number */
MY_ATTRIBUTE((warn_unused_result));
/********************************************************************//**
Get total buffer pool statistics. */
UNIV_INTERN
void
buf_get_total_list_len(
/*===================*/
ulint* LRU_len, /*!< out: length of all LRU lists */
ulint* free_len, /*!< out: length of all free lists */
ulint* flush_list_len);/*!< out: length of all flush lists */
/********************************************************************//**
Get total list size in bytes from all buffer pools. */
UNIV_INTERN
void
buf_get_total_list_size_in_bytes(
/*=============================*/
buf_pools_list_size_t* buf_pools_list_size); /*!< out: list sizes
in all buffer pools */
/********************************************************************//**
Get total buffer pool statistics. */
UNIV_INTERN
void
buf_get_total_stat(
/*===============*/
buf_pool_stat_t*tot_stat); /*!< out: buffer pool stats */
/*********************************************************************//**
Get the nth chunk's buffer block in the specified buffer pool.
@return the nth chunk's buffer block. */
UNIV_INLINE
buf_block_t*
buf_get_nth_chunk_block(
/*====================*/
const buf_pool_t* buf_pool, /*!< in: buffer pool instance */
ulint n, /*!< in: nth chunk in the buffer pool */
ulint* chunk_size); /*!< in: chunk size */
/********************************************************************//**
Calculate the checksum of a page from compressed table and update the page. */
UNIV_INTERN
void
buf_flush_update_zip_checksum(
/*==========================*/
buf_frame_t* page, /*!< in/out: Page to update */
ulint zip_size, /*!< in: Compressed page size */
lsn_t lsn); /*!< in: Lsn to stamp on the page */
#endif /* !UNIV_HOTBACKUP */
#ifdef UNIV_DEBUG
/********************************************************************//**
Checks if buf_pool->zip_mutex is owned and is serving for a given page as its
block mutex.
@return true if buf_pool->zip_mutex is owned. */
UNIV_INLINE
bool
buf_own_zip_mutex_for_page(
/*=======================*/
const buf_page_t* bpage)
MY_ATTRIBUTE((nonnull,warn_unused_result));
#endif /* UNIV_DEBUG */
/** The common buffer control block structure
for compressed and uncompressed frames */
/** Number of bits used for buffer page states. */
#define BUF_PAGE_STATE_BITS 3
struct buf_page_t{
/** @name General fields
None of these bit-fields must be modified without holding
buf_page_get_mutex() [buf_block_t::mutex or
buf_pool->zip_mutex], since they can be stored in the same
machine word. */
/* @{ */
ib_uint32_t space; /*!< tablespace id. */
ib_uint32_t offset; /*!< page number. */
/** count of how manyfold this block is currently bufferfixed */
#ifdef PAGE_ATOMIC_REF_COUNT
ib_uint32_t buf_fix_count;
/** type of pending I/O operation; Transitions from BUF_IO_NONE to
BUF_IO_WRITE and back are protected by the buf_page_get_mutex() mutex
and the corresponding flush state mutex. The flush state mutex
protection for io_fix and flush_type is not strictly required, but it
ensures consistent buffer pool instance state snapshots in
buf_pool_validate_instance(). @see enum buf_io_fix */
byte io_fix;
byte state;
#else
unsigned buf_fix_count:19;
/** type of pending I/O operation; also protected by
buf_pool->mutex for writes only @see enum buf_io_fix */
unsigned io_fix:2;
/*!< state of the control block.
State transitions from BUF_BLOCK_READY_FOR_USE to BUF_BLOCK_MEMORY
need not be protected by buf_page_get_mutex(). @see enum buf_page_state.
State changes that are relevant to page_hash are additionally protected
by the appropriate page_hash mutex i.e.: if a page is in page_hash or
is being added to/removed from page_hash then the corresponding changes
must also be protected by page_hash mutex. */
unsigned state:BUF_PAGE_STATE_BITS;
#endif /* PAGE_ATOMIC_REF_COUNT */
#ifndef UNIV_HOTBACKUP
unsigned flush_type:2; /*!< if this block is currently being
flushed to disk, this tells the
flush_type. Writes during flushing
protected by buf_page_get_mutex_enter()
mutex and the corresponding flush state
mutex.
@see buf_flush_t */
unsigned buf_pool_index:6;/*!< index number of the buffer pool
that this block belongs to */
# if MAX_BUFFER_POOLS > 64
# error "MAX_BUFFER_POOLS > 64; redefine buf_pool_index:6"
# endif
/* @} */
#endif /* !UNIV_HOTBACKUP */
page_zip_des_t zip; /*!< compressed page; zip.data
(but not the data it points to) is
protected by buf_pool->zip_mutex;
state == BUF_BLOCK_ZIP_PAGE and
zip.data == NULL means an active
buf_pool->watch */
#ifndef UNIV_HOTBACKUP
buf_page_t* hash; /*!< node used in chaining to
buf_pool->page_hash or
buf_pool->zip_hash */
#ifdef UNIV_DEBUG
ibool in_page_hash; /*!< TRUE if in buf_pool->page_hash */
ibool in_zip_hash; /*!< TRUE if in buf_pool->zip_hash */
#endif /* UNIV_DEBUG */
/** @name Page flushing fields */
/* @{ */
UT_LIST_NODE_T(buf_page_t) list;
/*!< based on state, this is a
list node, protected either by
a corresponding list mutex,
in one of the following lists in
buf_pool:
- BUF_BLOCK_NOT_USED: free
- BUF_BLOCK_FILE_PAGE: flush_list
- BUF_BLOCK_ZIP_DIRTY: flush_list
- BUF_BLOCK_ZIP_PAGE: zip_clean
If bpage is part of flush_list
then the node pointers are
covered by buf_pool->flush_list_mutex.
Otherwise these pointers are
protected by a corresponding list
mutex.
The contents of the list node
is undefined if !in_flush_list
&& state == BUF_BLOCK_FILE_PAGE,
or if state is one of
BUF_BLOCK_MEMORY,
BUF_BLOCK_REMOVE_HASH or
BUF_BLOCK_READY_IN_USE. */
#ifdef UNIV_DEBUG
ibool in_flush_list; /*!< TRUE if in buf_pool->flush_list;
when buf_pool->flush_list_mutex is
free, the following should hold:
in_flush_list
== (state == BUF_BLOCK_FILE_PAGE
|| state == BUF_BLOCK_ZIP_DIRTY)
Writes to this field must be
covered by both block->mutex
and buf_pool->flush_list_mutex. Hence
reads can happen while holding
any one of the two mutexes */
ibool in_free_list; /*!< TRUE if in buf_pool->free; when
buf_pool->free_list_mutex is free, the
following should hold: in_free_list
== (state == BUF_BLOCK_NOT_USED) */
#endif /* UNIV_DEBUG */
lsn_t newest_modification;
/*!< log sequence number of
the youngest modification to
this block, zero if not
modified. Protected by block
mutex */
lsn_t oldest_modification;
/*!< log sequence number of
the START of the log entry
written of the oldest
modification to this block
which has not yet been flushed
on disk; zero if all
modifications are on disk.
Writes to this field must be
covered by both block->mutex
and buf_pool->flush_list_mutex. Hence
reads can happen while holding
any one of the two mutexes */
/* @} */
/** @name LRU replacement algorithm fields */
/* @{ */
UT_LIST_NODE_T(buf_page_t) LRU;
/*!< node of the LRU list */
#ifdef UNIV_DEBUG
ibool in_LRU_list; /*!< TRUE if the page is in
the LRU list; used in
debugging */
#endif /* UNIV_DEBUG */
unsigned old:1; /*!< TRUE if the block is in the old
blocks in buf_pool->LRU_old. Protected
by the LRU list mutex. May be read for
heuristics purposes under the block
mutex instead. */
unsigned freed_page_clock:31;/*!< the value of
buf_pool->freed_page_clock
when this block was the last
time put to the head of the
LRU list; a thread is allowed
to read this for heuristic
purposes without holding any
mutex or latch */
/* @} */
unsigned access_time; /*!< time of first access, or
0 if the block was never accessed
in the buffer pool. Protected by
block mutex */
ibool is_corrupt;
# if defined UNIV_DEBUG_FILE_ACCESSES || defined UNIV_DEBUG
ibool file_page_was_freed;
/*!< this is set to TRUE when
fsp frees a page in buffer pool;
protected by buf_pool->zip_mutex
or buf_block_t::mutex. */
# endif /* UNIV_DEBUG_FILE_ACCESSES || UNIV_DEBUG */
#endif /* !UNIV_HOTBACKUP */
};
/** The buffer control block structure */
struct buf_block_t{
/** @name General fields */
/* @{ */
buf_page_t page; /*!< page information; this must
be the first field, so that
buf_pool->page_hash can point
to buf_page_t or buf_block_t */
byte* frame; /*!< pointer to buffer frame which
is of size UNIV_PAGE_SIZE, and
aligned to an address divisible by
UNIV_PAGE_SIZE */
#ifndef UNIV_HOTBACKUP
UT_LIST_NODE_T(buf_block_t) unzip_LRU;
/*!< node of the decompressed LRU list;
a block is in the unzip_LRU list
if page.state == BUF_BLOCK_FILE_PAGE
and page.zip.data != NULL */
#ifdef UNIV_DEBUG
ibool in_unzip_LRU_list;/*!< TRUE if the page is in the
decompressed LRU list;
used in debugging */
#endif /* UNIV_DEBUG */
ib_mutex_t mutex; /*!< mutex protecting this block:
state, io_fix, buf_fix_count,
and accessed; we introduce this new
mutex in InnoDB-5.1 to relieve
contention on the buffer pool mutex */
rw_lock_t lock; /*!< read-write lock of the buffer
frame */
unsigned lock_hash_val:32;/*!< hashed value of the page address
in the record lock hash table;
protected by buf_block_t::lock
(or buf_block_t::mutex in
buf_page_get_gen(),
buf_page_init_for_read()
and buf_page_create()) */
ibool check_index_page_at_flush;
/*!< TRUE if we know that this is
an index page, and want the database
to check its consistency before flush;
note that there may be pages in the
buffer pool which are index pages,
but this flag is not set because
we do not keep track of all pages;
NOT protected by any mutex */
/* @} */
/** @name Optimistic search field */
/* @{ */
ib_uint64_t modify_clock; /*!< this clock is incremented every
time a pointer to a record on the
page may become obsolete; this is
used in the optimistic cursor
positioning: if the modify clock has
not changed, we know that the pointer
is still valid; this field may be
changed if the thread (1) owns the LRU
list mutex and the page is not
bufferfixed, or (2) the thread has an
x-latch on the block */
/* @} */
/** @name Hash search fields (unprotected)
NOTE that these fields are NOT protected by any semaphore! */
/* @{ */
ulint n_hash_helps; /*!< counter which controls building
of a new hash index for the page */
ulint n_fields; /*!< recommended prefix length for hash
search: number of full fields */
ulint n_bytes; /*!< recommended prefix: number of bytes
in an incomplete field */
ibool left_side; /*!< TRUE or FALSE, depending on
whether the leftmost record of several
records with the same prefix should be
indexed in the hash index */
/* @} */
/** @name Hash search fields
These 5 fields may only be modified when we have
an x-latch on btr_search_latch AND
- we are holding an s-latch or x-latch on buf_block_t::lock or
- we know that buf_block_t::buf_fix_count == 0.
An exception to this is when we init or create a page
in the buffer pool in buf0buf.cc.
Another exception is that assigning block->index = NULL
is allowed whenever holding an x-latch on btr_search_latch. */
/* @{ */
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
ulint n_pointers; /*!< used in debugging: the number of
pointers in the adaptive hash index
pointing to this frame */
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
unsigned curr_n_fields:10;/*!< prefix length for hash indexing:
number of full fields */
unsigned curr_n_bytes:15;/*!< number of bytes in hash
indexing */
unsigned curr_left_side:1;/*!< TRUE or FALSE in hash indexing */
dict_index_t* index; /*!< Index for which the
adaptive hash index has been
created, or NULL if the page
does not exist in the
index. Note that it does not
guarantee that the index is
complete, though: there may
have been hash collisions,
record deletions, etc. */
/* @} */
# ifdef UNIV_SYNC_DEBUG
/** @name Debug fields */
/* @{ */
rw_lock_t debug_latch; /*!< in the debug version, each thread
which bufferfixes the block acquires
an s-latch here; so we can use the
debug utilities in sync0rw */
/* @} */
# endif
#endif /* !UNIV_HOTBACKUP */
};
/** Check if a buf_block_t object is in a valid state
@param block buffer block
@return TRUE if valid */
#define buf_block_state_valid(block) \
(buf_block_get_state(block) >= BUF_BLOCK_NOT_USED \
&& (buf_block_get_state(block) <= BUF_BLOCK_REMOVE_HASH))
#ifndef UNIV_HOTBACKUP
/**********************************************************************//**
Compute the hash fold value for blocks in buf_pool->zip_hash. */
/* @{ */
#define BUF_POOL_ZIP_FOLD_PTR(ptr) ((ulint) (ptr) / UNIV_PAGE_SIZE)
#define BUF_POOL_ZIP_FOLD(b) BUF_POOL_ZIP_FOLD_PTR((b)->frame)
#define BUF_POOL_ZIP_FOLD_BPAGE(b) BUF_POOL_ZIP_FOLD((buf_block_t*) (b))
/* @} */
/** Struct that is embedded in the free zip blocks */
struct buf_buddy_free_t {
union {
ulint size; /*!< size of the block */
byte bytes[FIL_PAGE_DATA];
/*!< stamp[FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID]
== BUF_BUDDY_FREE_STAMP denotes a free
block. If the space_id field of buddy
block != BUF_BUDDY_FREE_STAMP, the block
is not in any zip_free list. If the
space_id is BUF_BUDDY_FREE_STAMP then
stamp[0] will contain the
buddy block size. */
} stamp;
buf_page_t bpage; /*!< Embedded bpage descriptor */
UT_LIST_NODE_T(buf_buddy_free_t) list;
/*!< Node of zip_free list */
};
/** @brief The buffer pool statistics structure. */
struct buf_pool_stat_t{
ulint n_page_gets; /*!< number of page gets performed;
also successful searches through
the adaptive hash index are
counted as page gets. */
ulint n_pages_read; /*!< number read operations. Accessed
atomically. */
ulint n_pages_written;/*!< number write operations. Accessed
atomically.*/
ulint n_pages_created;/*!< number of pages created
in the pool with no read */
ulint n_ra_pages_read_rnd;/*!< number of pages read in
as part of random read ahead */
ulint n_ra_pages_read;/*!< number of pages read in
as part of read ahead */
ulint n_ra_pages_evicted;/*!< number of read ahead
pages that are evicted without
being accessed */
ulint n_pages_made_young; /*!< number of pages made young, in
calls to buf_LRU_make_block_young() */
ulint n_pages_not_made_young; /*!< number of pages not made
young because the first access
was not long enough ago, in
buf_page_peek_if_too_old() */
ulint LRU_bytes; /*!< LRU size in bytes */
ulint flush_list_bytes;/*!< flush_list size in bytes */
ulint buf_lru_flush_page_count;
};
/** Statistics of buddy blocks of a given size. */
struct buf_buddy_stat_t {
/** Number of blocks allocated from the buddy system. */
ulint used;
/** Number of blocks relocated by the buddy system. */
ib_uint64_t relocated;
/** Total duration of block relocations, in microseconds. */
ib_uint64_t relocated_usec;
};
/** @brief The buffer pool structure.
NOTE! The definition appears here only for other modules of this
directory (buf) to see it. Do not use from outside! */
struct buf_pool_t{
/** @name General fields */
/* @{ */
ib_mutex_t zip_mutex; /*!< Zip mutex of this buffer
pool instance, protects compressed
only pages (of type buf_page_t, not
buf_block_t */
ib_prio_mutex_t LRU_list_mutex;
ib_prio_mutex_t free_list_mutex;
ib_mutex_t zip_free_mutex;
ib_mutex_t zip_hash_mutex;
ib_mutex_t flush_state_mutex; /*!< Flush state protection
mutex */
ulint instance_no; /*!< Array index of this buffer
pool instance */
ulint old_pool_size; /*!< Old pool size in bytes */
ulint curr_pool_size; /*!< Current pool size in bytes */
ulint LRU_old_ratio; /*!< Reserve this much of the buffer
pool for "old" blocks */
#ifdef UNIV_DEBUG
ulint buddy_n_frames; /*!< Number of frames allocated from
the buffer pool to the buddy system */
#endif
ulint n_chunks; /*!< number of buffer pool chunks */
buf_chunk_t* chunks; /*!< buffer pool chunks */
ulint curr_size; /*!< current pool size in pages */
ulint read_ahead_area;/*!< size in pages of the area which
the read-ahead algorithms read if
invoked */
hash_table_t* page_hash; /*!< hash table of buf_page_t or
buf_block_t file pages,
buf_page_in_file() == TRUE,
indexed by (space_id, offset).
page_hash is protected by an
array of mutexes. */
hash_table_t* zip_hash; /*!< hash table of buf_block_t blocks
whose frames are allocated to the
zip buddy system,
indexed by block->frame */
ulint n_pend_reads; /*!< number of pending read
operations. Accessed atomically */
ulint n_pend_unzip; /*!< number of pending decompressions.
Accesssed atomically */
time_t last_printout_time;
/*!< when buf_print_io was last time
called. Accesses not protected */
buf_buddy_stat_t buddy_stat[BUF_BUDDY_SIZES_MAX + 1];
/*!< Statistics of buddy system,
indexed by block size. Protected by
zip_free_mutex. */
buf_pool_stat_t stat; /*!< current statistics */
buf_pool_stat_t old_stat; /*!< old statistics */
/* @} */
/** @name Page flushing algorithm fields */
/* @{ */
ib_mutex_t flush_list_mutex;/*!< mutex protecting the
flush list access. This mutex
protects flush_list, flush_rbt
and bpage::list pointers when
the bpage is on flush_list. It
also protects writes to
bpage::oldest_modification and
flush_list_hp */
const buf_page_t* flush_list_hp;/*!< "hazard pointer"
used during scan of flush_list
while doing flush list batch.
Protected by flush_list_mutex */
UT_LIST_BASE_NODE_T(buf_page_t) flush_list;
/*!< base node of the modified block
list */
ibool init_flush[BUF_FLUSH_N_TYPES];
/*!< this is TRUE when a flush of the
given type is being initialized.
Protected by flush_state_mutex. */
ulint n_flush[BUF_FLUSH_N_TYPES];
/*!< this is the number of pending
writes in the given flush type.
Protected by flush_state_mutex. */
os_event_t no_flush[BUF_FLUSH_N_TYPES];
/*!< this is in the set state
when there is no flush batch
of the given type running;
os_event_set() and os_event_reset()
are protected by
buf_pool_t::flush_state_mutex */
ib_rbt_t* flush_rbt; /*!< a red-black tree is used
exclusively during recovery to
speed up insertions in the
flush_list. This tree contains
blocks in order of
oldest_modification LSN and is
kept in sync with the
flush_list.
Each member of the tree MUST
also be on the flush_list.
This tree is relevant only in
recovery and is set to NULL
once the recovery is over.
Protected by flush_list_mutex */
ulint freed_page_clock;/*!< a sequence number used
to count the number of buffer
blocks removed from the end of
the LRU list; NOTE that this
counter may wrap around at 4
billion! A thread is allowed
to read this for heuristic
purposes without holding any
mutex or latch. For non-heuristic
purposes protected by LRU_list_mutex */
ibool try_LRU_scan; /*!< Set to FALSE when an LRU
scan for free block fails. This
flag is used to avoid repeated
scans of LRU list when we know
that there is no free block
available in the scan depth for
eviction. Set to TRUE whenever
we flush a batch from the
buffer pool. Accessed atomically. */
/* @} */
/** @name LRU replacement algorithm fields */
/* @{ */
UT_LIST_BASE_NODE_T(buf_page_t) free;
/*!< base node of the free
block list */
UT_LIST_BASE_NODE_T(buf_page_t) LRU;
/*!< base node of the LRU list */
buf_page_t* LRU_old; /*!< pointer to the about
LRU_old_ratio/BUF_LRU_OLD_RATIO_DIV
oldest blocks in the LRU list;
NULL if LRU length less than
BUF_LRU_OLD_MIN_LEN;
NOTE: when LRU_old != NULL, its length
should always equal LRU_old_len */
ulint LRU_old_len; /*!< length of the LRU list from
the block to which LRU_old points
onward, including that block;
see buf0lru.cc for the restrictions
on this value; 0 if LRU_old == NULL;
NOTE: LRU_old_len must be adjusted
whenever LRU_old shrinks or grows! */
UT_LIST_BASE_NODE_T(buf_block_t) unzip_LRU;
/*!< base node of the
unzip_LRU list. The list is protected
by LRU list mutex. */
/* @} */
/** @name Buddy allocator fields
The buddy allocator is used for allocating compressed page
frames and buf_page_t descriptors of blocks that exist
in the buffer pool only in compressed form. */
/* @{ */
#if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
UT_LIST_BASE_NODE_T(buf_page_t) zip_clean;
/*!< unmodified compressed pages */
#endif /* UNIV_DEBUG || UNIV_BUF_DEBUG */
UT_LIST_BASE_NODE_T(buf_buddy_free_t) zip_free[BUF_BUDDY_SIZES_MAX];
/*!< buddy free lists */
buf_page_t* watch;
/*!< Sentinel records for buffer
pool watches. */
#if BUF_BUDDY_LOW > UNIV_ZIP_SIZE_MIN
# error "BUF_BUDDY_LOW > UNIV_ZIP_SIZE_MIN"
#endif
/* @} */
};
/** @name Accessors for buffer pool mutexes
Use these instead of accessing buffer pool mutexes directly. */
/* @{ */
/** Test if flush list mutex is owned. */
#define buf_flush_list_mutex_own(b) mutex_own(&b->flush_list_mutex)
/** Acquire the flush list mutex. */
#define buf_flush_list_mutex_enter(b) do { \
mutex_enter(&b->flush_list_mutex); \
} while (0)
/** Release the flush list mutex. */
# define buf_flush_list_mutex_exit(b) do { \
mutex_exit(&b->flush_list_mutex); \
} while (0)
/** Test if block->mutex is owned. */
#define buf_block_mutex_own(b) mutex_own(&(b)->mutex)
/** Acquire the block->mutex. */
#define buf_block_mutex_enter(b) do { \
mutex_enter(&(b)->mutex); \
} while (0)
/** Release the trx->mutex. */
#define buf_block_mutex_exit(b) do { \
mutex_exit(&(b)->mutex); \
} while (0)
/** Get appropriate page_hash_lock. */
# define buf_page_hash_lock_get(b, f) \
hash_get_lock(b->page_hash, f)
#ifdef UNIV_SYNC_DEBUG
/** Test if page_hash lock is held in s-mode. */
# define buf_page_hash_lock_held_s(b, p) \
rw_lock_own(buf_page_hash_lock_get(b, \
buf_page_address_fold(p->space, \
p->offset)), \
RW_LOCK_SHARED)
/** Test if page_hash lock is held in x-mode. */
# define buf_page_hash_lock_held_x(b, p) \
rw_lock_own(buf_page_hash_lock_get(b, \
buf_page_address_fold(p->space, \
p->offset)), \
RW_LOCK_EX)
/** Test if page_hash lock is held in x or s-mode. */
# define buf_page_hash_lock_held_s_or_x(b, p) \
(buf_page_hash_lock_held_s(b, p) \
|| buf_page_hash_lock_held_x(b, p))
# define buf_block_hash_lock_held_s(b, p) \
buf_page_hash_lock_held_s(b, &(p->page))
# define buf_block_hash_lock_held_x(b, p) \
buf_page_hash_lock_held_x(b, &(p->page))
# define buf_block_hash_lock_held_s_or_x(b, p) \
buf_page_hash_lock_held_s_or_x(b, &(p->page))
#else /* UNIV_SYNC_DEBUG */
# define buf_page_hash_lock_held_s(b, p) (TRUE)
# define buf_page_hash_lock_held_x(b, p) (TRUE)
# define buf_page_hash_lock_held_s_or_x(b, p) (TRUE)
# define buf_block_hash_lock_held_s(b, p) (TRUE)
# define buf_block_hash_lock_held_x(b, p) (TRUE)
# define buf_block_hash_lock_held_s_or_x(b, p) (TRUE)
#endif /* UNIV_SYNC_DEBUG */
#endif /* !UNIV_HOTBACKUP */
/* @} */
/**********************************************************************
Let us list the consistency conditions for different control block states.
NOT_USED: is in free list, not in LRU list, not in flush list, nor
page hash table
READY_FOR_USE: is not in free list, LRU list, or flush list, nor page
hash table
MEMORY: is not in free list, LRU list, or flush list, nor page
hash table
FILE_PAGE: space and offset are defined, is in page hash table
if io_fix == BUF_IO_WRITE,
pool: no_flush[flush_type] is in reset state,
pool: n_flush[flush_type] > 0
(1) if buf_fix_count == 0, then
is in LRU list, not in free list
is in flush list,
if and only if oldest_modification > 0
is x-locked,
if and only if io_fix == BUF_IO_READ
is s-locked,
if and only if io_fix == BUF_IO_WRITE
(2) if buf_fix_count > 0, then
is not in LRU list, not in free list
is in flush list,
if and only if oldest_modification > 0
if io_fix == BUF_IO_READ,
is x-locked
if io_fix == BUF_IO_WRITE,
is s-locked
State transitions:
NOT_USED => READY_FOR_USE
READY_FOR_USE => MEMORY
READY_FOR_USE => FILE_PAGE
MEMORY => NOT_USED
FILE_PAGE => NOT_USED NOTE: This transition is allowed if and only if
(1) buf_fix_count == 0,
(2) oldest_modification == 0, and
(3) io_fix == 0.
*/
#if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
/** Functor to validate the LRU list. */
struct CheckInLRUList {
void operator()(const buf_page_t* elem) const
{
ut_a(elem->in_LRU_list);
}
};
/** Functor to validate the LRU list. */
struct CheckInFreeList {
void operator()(const buf_page_t* elem) const
{
ut_a(elem->in_free_list);
}
};
struct CheckUnzipLRUAndLRUList {
void operator()(const buf_block_t* elem) const
{
ut_a(elem->page.in_LRU_list);
ut_a(elem->in_unzip_LRU_list);
}
};
#endif /* UNIV_DEBUG || defined UNIV_BUF_DEBUG */
#ifndef UNIV_NONINL
#include "buf0buf.ic"
#endif
#endif
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