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/*****************************************************************************
Copyright (c) 1995, 2019, Oracle and/or its affiliates. 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, version 2.0, as published by the
Free Software Foundation.
This program is also distributed with certain software (including but not
limited to OpenSSL) that is licensed under separate terms, as designated in a
particular file or component or in included license documentation. The authors
of MySQL hereby grant you an additional permission to link the program and
your derivative works with the separately licensed software that they have
included with MySQL.
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, version 2.0,
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 St, Fifth Floor, Boston, MA 02110-1301 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 "buf0types.h"
#include "fil0fil.h"
#include "hash0hash.h"
#include "log0log.h"
#include "mtr0types.h"
#include "os0proc.h"
#include "page0types.h"
#include "srv0srv.h"
#include "univ.i"
#include "ut0byte.h"
#include "ut0rbt.h"
#include "buf/buf.h"
#include <ostream>
#include "lizard0tcn.h"
// Forward declaration
struct fil_addr_t;
/** @name Modes for buf_page_get_gen */
/* @{ */
enum class Page_fetch {
/** Get always */
NORMAL,
/** Same as NORMAL, but hint that the fetch is part of a large scan.
Try not to flood the buffer pool with pages that may not be accessed again
any time soon. */
SCAN,
/** get if in pool */
IF_IN_POOL,
/** get if in pool, do not make the block young in the LRU list */
PEEK_IF_IN_POOL,
/** 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 */
NO_LATCH,
/** Get the page only if it's in the buffer pool, if not then set a watch on
the page. */
IF_IN_POOL_OR_WATCH,
/** Like Page_fetch::NORMAL, but do not mind if the file page has been
freed. */
POSSIBLY_FREED
};
/* @} */
/** @name Modes for buf_page_get_known_nowait */
/* @{ */
enum class Cache_hint {
/** 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*/
MAKE_YOUNG = 51,
/** Preserve the current LRU position of the block. */
KEEP_OLD = 52
};
/* @} */
/** Number of bits to representing a buffer pool ID */
constexpr ulint MAX_BUFFER_POOLS_BITS = 6;
/** The maximum number of buffer pools that can be defined */
constexpr ulint MAX_BUFFER_POOLS = (1 << MAX_BUFFER_POOLS_BITS);
/** Maximum number of concurrent buffer pool watches */
#define BUF_POOL_WATCH_SIZE (srv_n_purge_threads + 1)
/** The maximum number of page_hash locks */
constexpr ulint MAX_PAGE_HASH_LOCKS = 1024;
/** The buffer pools of the database */
extern buf_pool_t *buf_pool_ptr;
/** true when withdrawing buffer pool pages might cause page relocation */
extern volatile bool buf_pool_withdrawing;
/** the clock is incremented every time a pointer to a page may become
obsolete */
extern volatile ulint buf_withdraw_clock;
#ifdef UNIV_HOTBACKUP
/** first block, for --apply-log */
extern buf_block_t *back_block1;
/** second block, for page reorganize */
extern buf_block_t *back_block2;
#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 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.
@param[in] total_size Size of the total pool in bytes.
@param[in] n_instances Number of buffer pool instances to create.
@return DB_SUCCESS if success, DB_ERROR if not enough memory or error */
dberr_t buf_pool_init(ulint total_size, ulint n_instances);
/** Frees the buffer pool at shutdown. This must not be invoked before
freeing all mutexes. */
void buf_pool_free_all();
/** Determines if a block is intended to be withdrawn.
@param[in] buf_pool buffer pool instance
@param[in] block pointer to control block
@retval true if will be withdrawn */
bool buf_block_will_withdrawn(buf_pool_t *buf_pool, const buf_block_t *block);
/** Determines if a frame is intended to be withdrawn.
@param[in] buf_pool buffer pool instance
@param[in] ptr pointer to a frame
@retval true if will be withdrawn */
bool buf_frame_will_withdrawn(buf_pool_t *buf_pool, const byte *ptr);
/** This is the thread for resizing buffer pool. It waits for an event and
when waked up either performs a resizing and sleeps again. */
void buf_resize_thread();
/** Checks if innobase_should_madvise_buf_pool() value has changed since we've
last check and if so, then updates buf_pool_should_madvise and calls madvise
for all chunks in all srv_buf_pool_instances.
@see buf_pool_should_madvise comment for a longer explanation. */
void buf_pool_update_madvise();
/** Clears the adaptive hash index on all pages in the buffer pool. */
void buf_pool_clear_hash_index(void);
/** 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);
#endif /* !UNIV_HOTBACKUP */
/** Gets the smallest oldest_modification lsn among all of the earliest
added pages in flush lists. In other words - takes the last dirty page
from each flush list, and calculates minimum oldest_modification among
all of them. Does not acquire global lock for the whole process, so the
result might come from inconsistent view on flush lists.
@note Note that because of the relaxed order in each flush list, this
functions no longer returns the smallest oldest_modification among all
of the dirty pages. If you wanted to have a safe lsn, which is smaller
than every oldest_modification, you would need to use another function:
buf_pool_get_oldest_modification_lwm().
Returns zero if there were no dirty pages (flush lists were empty).
@return minimum oldest_modification of last pages from flush lists,
zero if flush lists were empty */
lsn_t buf_pool_get_oldest_modification_approx(void);
/** Gets a safe low watermark for oldest_modification. It's guaranteed
that there were no dirty pages with smaller oldest_modification in the
whole flush lists.
Returns zero if flush lists were empty, be careful in such case, because
taking the newest lsn is probably not a good idea. If you wanted to rely
on some lsn in such case, you would need to follow pattern:
dpa_lsn = log_buffer_dirty_pages_added_up_to_lsn(*log_sys);
lwm_lsn = buf_pool_get_oldest_modification_lwm();
if (lwm_lsn == 0) lwm_lsn = dpa_lsn;
The order is important to avoid race conditions.
@remarks
It's guaranteed that the returned value will not be smaller than the
last checkpoint lsn. It's not guaranteed that the returned value is
the maximum possible. It's just the best effort for the low cost.
It basically takes result of buf_pool_get_oldest_modification_approx()
and subtracts maximum possible lag introduced by relaxed order in
flush lists (srv_log_recent_closed_size).
@return safe low watermark for oldest_modification of dirty pages,
or zero if flush lists were empty; if non-zero, it is then
guaranteed not to be at block boundary (and it points to lsn
inside data fragment of block) */
lsn_t buf_pool_get_oldest_modification_lwm(void);
#ifndef UNIV_HOTBACKUP
/** 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. */
/** Allocates a buffer block.
@return own: the allocated block, in state BUF_BLOCK_MEMORY */
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.
@param[in] buf buffer to copy to
@param[in] frame buffer frame
@return buf */
UNIV_INLINE
byte *buf_frame_copy(byte *buf, const buf_frame_t *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(ID, SIZE, LA, MTR) \
buf_page_get_gen(ID, SIZE, LA, NULL, Page_fetch::NORMAL, __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(ID, SIZE, MTR) \
buf_page_get_gen(ID, SIZE, RW_NO_LATCH, NULL, Page_fetch::NO_LATCH, \
__FILE__, __LINE__, MTR)
/** This is the general function used to get optimistic access to a database
page.
@param[in] rw_latch RW_S_LATCH, RW_X_LATCH
@param[in,out] block guessed block
@param[in] modify_clock modify clock value
@param[in] fetch_mode Fetch mode
@param[in] file file name
@param[in] line line where called
@param[in,out] mtr mini-transaction
@return true if success */
bool buf_page_optimistic_get(ulint rw_latch, buf_block_t *block,
uint64_t modify_clock, Page_fetch fetch_mode,
const char *file, ulint line, mtr_t *mtr);
/** This is used to get access to a known database page, when no waiting can be
done.
@param[in] rw_latch RW_S_LATCH or RW_X_LATCH.
@param[in] block The known page.
@param[in] hint Cache_hint::MAKE_YOUNG or Cache_hint::KEEP_OLD
@param[in] file File name from where it was called.
@param[in] line Line from where it was called.
@param[in,out] mtr Mini-transaction covering the fetch
@return true if success */
bool buf_page_get_known_nowait(ulint rw_latch, buf_block_t *block,
Cache_hint hint, const char *file, ulint line,
mtr_t *mtr);
/** 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.
@param[in] page_id page id
@param[in] file file name
@param[in] line line where called
@param[in] mtr mini-transaction
@return pointer to a page or NULL */
const buf_block_t *buf_page_try_get_func(const page_id_t &page_id,
const char *file, ulint line,
mtr_t *mtr);
/** 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[in] page_id page identifier
@param[in] mtr mini-transaction
@return the page if in buffer pool, NULL if not */
#define buf_page_try_get(page_id, mtr) \
buf_page_try_get_func((page_id), __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.
@param[in] page_id page id
@param[in] page_size page size
@return pointer to the block */
buf_page_t *buf_page_get_zip(const page_id_t &page_id,
const page_size_t &page_size);
/** This is the general function used to get access to a database page.
@param[in] page_id page id
@param[in] page_size page size
@param[in] rw_latch RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH
@param[in] guess guessed block or NULL
@param[in] mode Fetch mode.
@param[in] file file name
@param[in] line line where called
@param[in] mtr mini-transaction
@param[in] dirty_with_no_latch mark page as dirty even if page is being
pinned without any latch
@return pointer to the block or NULL */
buf_block_t *buf_page_get_gen(const page_id_t &page_id,
const page_size_t &page_size, ulint rw_latch,
buf_block_t *guess, Page_fetch mode,
const char *file, ulint line, mtr_t *mtr,
bool dirty_with_no_latch = false);
/** 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). The page is latched by passed mtr.
@param[in] page_id page id
@param[in] page_size page size
@param[in] rw_latch RW_SX_LATCH, RW_X_LATCH
@param[in] mtr mini-transaction
@return pointer to the block, page bufferfixed */
buf_block_t *buf_page_create(const page_id_t &page_id,
const page_size_t &page_size,
rw_lock_type_t rw_latch, mtr_t *mtr);
#else /* !UNIV_HOTBACKUP */
/** Inits a page to the buffer buf_pool, for use in mysqlbackup --restore.
@param[in] page_id page id
@param[in] page_size page size
@param[in,out] block block to init */
void meb_page_init(const page_id_t &page_id, const page_size_t &page_size,
buf_block_t *block);
#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 */
/** Releases a latch, if specified.
@param[in] block buffer block
@param[in] rw_latch RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH */
UNIV_INLINE
void buf_page_release_latch(buf_block_t *block, ulint rw_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.
@param[in,out] bpage buffer block of a file page */
void buf_page_make_young(buf_page_t *bpage);
/** 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.
@param[in] page_id page id
@return true if found in the page hash table */
UNIV_INLINE
ibool buf_page_peek(const page_id_t &page_id);
#ifdef 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.
@param[in] page_id page id
@return control block if found in page hash table, otherwise NULL */
buf_page_t *buf_page_set_file_page_was_freed(const page_id_t &page_id);
/** 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.
@param[in] page_id page id
@return control block if found in page hash table, otherwise NULL */
buf_page_t *buf_page_reset_file_page_was_freed(const page_id_t &page_id);
#endif /* 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((warn_unused_result));
/** 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((warn_unused_result));
/** Tells, for heuristics, 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.
The page must be either buffer-fixed, either its page hash must be locked.
@param[in] bpage block
@return true if block is close to MRU end of LRU */
UNIV_INLINE
ibool buf_page_peek_if_young(const buf_page_t *bpage);
/** 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 LRU list mutex.
@param[in] bpage block to make younger
@return true if should be made younger */
UNIV_INLINE
ibool buf_page_peek_if_too_old(const buf_page_t *bpage);
/** 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 */
/** Increment the modify clock.
The caller must
(1) own the buf_pool->mutex and block bufferfix count has to be zero,
(2) own X or SX latch on the block->lock, or
(3) operate on a thread-private temporary table
@param[in,out] block buffer block */
UNIV_INLINE
void buf_block_modify_clock_inc(buf_block_t *block);
/** Read the modify clock.
@param[in] block buffer block
@return modify_clock value */
UNIV_INLINE
uint64_t buf_block_get_modify_clock(const buf_block_t *block);
/** Increments the bufferfix count.
@param[in] file file name
@param[in] line line
@param[in,out] block block to bufferfix */
UNIV_INLINE
void buf_block_buf_fix_inc_func(
#ifdef UNIV_DEBUG
const char *file, ulint line,
#endif /* UNIV_DEBUG */
buf_block_t *block);
/** Increments the bufferfix count.
@param[in,out] bpage block to bufferfix
@return the count */
UNIV_INLINE
ulint buf_block_fix(buf_page_t *bpage);
/** Increments the bufferfix count.
@param[in,out] block block to bufferfix
@return the count */
UNIV_INLINE
ulint buf_block_fix(buf_block_t *block);
/** Decrements the bufferfix count.
@param[in,out] bpage block to bufferunfix
@return the remaining buffer-fix count */
UNIV_INLINE
ulint buf_block_unfix(buf_page_t *bpage);
#endif /* !UNIV_HOTBACKUP */
/** Decrements the bufferfix count.
@param[in,out] block block to bufferunfix
@return the remaining buffer-fix count */
UNIV_INLINE
ulint buf_block_unfix(buf_block_t *block);
#ifndef UNIV_HOTBACKUP
/** Unfixes the page, unlatches the page,
removes it from page_hash and removes it from LRU.
@param[in,out] bpage pointer to the block */
void buf_read_page_handle_error(buf_page_t *bpage);
#ifdef UNIV_DEBUG
/** Increments the bufferfix count.
@param[in,out] b block to bufferfix
@param[in] f file name where requested
@param[in] l line number where requested */
#define buf_block_buf_fix_inc(b, f, l) buf_block_buf_fix_inc_func(f, l, b)
#else /* UNIV_DEBUG */
/** Increments the bufferfix count.
@param[in,out] b block to bufferfix
@param[in] f file name where requested
@param[in] l line number where requested */
#define buf_block_buf_fix_inc(b, f, l) buf_block_buf_fix_inc_func(b)
#endif /* UNIV_DEBUG */
#else /* !UNIV_HOTBACKUP */
#define buf_block_modify_clock_inc(block) ((void)0)
#endif /* !UNIV_HOTBACKUP */
#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.
@param[in] ptr pointer to a buffer frame
@param[out] space space id
@param[out] addr page offset and byte offset */
UNIV_INLINE
void buf_ptr_get_fsp_addr(const void *ptr, space_id_t *space, fil_addr_t *addr);
/** 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((warn_unused_result));
#ifdef UNIV_DEBUG
/** Finds a block in the buffer pool that points to a
given compressed page. Used only to confirm that buffer pool does not contain a
given pointer, thus protected by zip_free_mutex.
@param[in] buf_pool buffer pool instance
@param[in] data pointer to compressed page
@return buffer block pointing to the compressed page, or NULL */
buf_block_t *buf_pool_contains_zip(buf_pool_t *buf_pool, const void *data);
#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 */
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. */
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.
@param[in] read_buf a database page
@param[in] page_size page size
@param[in] flags 0 or BUF_PAGE_PRINT_NO_CRASH or
BUF_PAGE_PRINT_NO_FULL */
void buf_page_print(const byte *read_buf, const page_size_t &page_size,
ulint flags);
/** Decompress a block.
@return true if successful */
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 */
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 */
ulint buf_get_n_pending_read_ios(void);
/** Prints info of the buffer i/o. */
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 */
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 */
/** Return the ratio in percents of modified pages in the buffer pool /
database pages in the buffer pool.
@return modified page percentage ratio */
double buf_get_modified_ratio_pct(void);
/** Refresh the statistics used to print per-second averages. */
void buf_refresh_io_stats_all();
/** Assert that all file pages in the buffer are in a replaceable state. */
void buf_must_be_all_freed(void);
/** Checks that there currently are no pending i/o-operations for the buffer
pool.
@return number of pending i/o */
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. */
void buf_pool_invalidate(void);
#endif /* !UNIV_HOTBACKUP */
/*========================================================================
--------------------------- LOWER LEVEL ROUTINES -------------------------
=========================================================================*/
#ifdef UNIV_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.
@param[in] block buffer page where we have acquired latch
@param[in] level latching order level */
UNIV_INLINE
void buf_block_dbg_add_level(buf_block_t *block, latch_level_t level);
#else /* UNIV_DEBUG */
#define buf_block_dbg_add_level(block, level) /* nothing */
#endif /* UNIV_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((warn_unused_result));
/** Sets the state of a block.
@param[in,out] bpage pointer to control block
@param[in] state state */
UNIV_INLINE
void buf_page_set_state(buf_page_t *bpage, enum buf_page_state state);
/** Sets the state of a block.
@param[in,out] block pointer to control block
@param[in] state state */
UNIV_INLINE
void buf_block_set_state(buf_block_t *block, enum buf_page_state 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((warn_unused_result));
#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((warn_unused_result));
/** Gets the mutex of a block.
@return pointer to mutex protecting bpage */
UNIV_INLINE
BPageMutex *buf_page_get_mutex(
const buf_page_t *bpage) /*!< in: pointer to control block */
MY_ATTRIBUTE((warn_unused_result));
/** 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((warn_unused_result));
/** Set the flush type of a page.
@param[in] bpage buffer page
@param[in] flush_type flush type */
UNIV_INLINE
void buf_page_set_flush_type(buf_page_t *bpage, buf_flush_t flush_type);
/** Map a block to a file page.
@param[in,out] block pointer to control block
@param[in] page_id page id */
UNIV_INLINE
void buf_block_set_file_page(buf_block_t *block, const page_id_t &page_id);
/** 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((warn_unused_result));
/** 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((warn_unused_result));
/** Sets the io_fix state of a block.
@param[in,out] bpage control block
@param[in] io_fix io_fix state */
UNIV_INLINE
void buf_page_set_io_fix(buf_page_t *bpage, enum buf_io_fix io_fix);
/** Sets the io_fix state of a block.
@param[in,out] block control block
@param[in] io_fix io_fix state */
UNIV_INLINE
void buf_block_set_io_fix(buf_block_t *block, enum buf_io_fix io_fix);
/** 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.
@param[in,out] bpage control block */
UNIV_INLINE
void buf_page_set_sticky(buf_page_t *bpage);
/** 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((warn_unused_result));
/** Determine if a block has been flagged old.
@param[in] bpage control block
@return true if old */
UNIV_INLINE
ibool buf_page_is_old(const buf_page_t *bpage)
MY_ATTRIBUTE((warn_unused_result));
/** Flag a block old.
@param[in,out] bpage control block
@param[in] old old */
UNIV_INLINE
void buf_page_set_old(buf_page_t *bpage, ibool old);
/** Determine the time of first access of a block in the buffer pool.
@return ut_time_monotonic_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((warn_unused_result));
/** Flag a block accessed. */
UNIV_INLINE
void buf_page_set_accessed(buf_page_t *bpage); /*!< in/out: control block */
/** Gets the buf_block_t handle of a buffered file block if an uncompressed
page frame exists, or NULL. page frame exists, or NULL. The caller must hold
either the appropriate hash lock in any mode, either the LRU list mutex. Note:
even though bpage is not declared a const we don't update its value. It is safe
to make this pure.
@param[in] bpage control block, or NULL
@return control block, or NULL */
UNIV_INLINE
buf_block_t *buf_page_get_block(buf_page_t *bpage)
MY_ATTRIBUTE((warn_unused_result));
#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((warn_unused_result));
#else /* UNIV_DEBUG */
#define buf_block_get_frame(block) (block)->frame
#endif /* UNIV_DEBUG */
#else /* !UNIV_HOTBACKUP */
#define buf_block_get_frame(block) (block)->frame
#endif /* !UNIV_HOTBACKUP */
/** 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)
/** Get a buffer block from an adaptive hash index pointer.
This function does not return if the block is not identified.
@param[in] ptr pointer to within a page frame
@return pointer to block, never NULL */
buf_block_t *buf_block_from_ahi(const byte *ptr);
#ifndef UNIV_HOTBACKUP
/** 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 */
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))
/** 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.
@param[out] err DB_SUCCESS or DB_TABLESPACE_DELETED
@param[in] mode BUF_READ_IBUF_PAGES_ONLY, ...
@param[in] page_id page id
@param[in] page_size page size
@param[in] unzip TRUE=request uncompressed page
@return pointer to the block or NULL */
buf_page_t *buf_page_init_for_read(dberr_t *err, ulint mode,
const page_id_t &page_id,
const page_size_t &page_size, ibool unzip);
/** Completes an asynchronous read or write request of a file page to or from
the buffer pool.
@param[in] bpage pointer to the block in question
@param[in] evict whether or not to evict the page from LRU list
@return true if successful */
bool buf_page_io_complete(buf_page_t *bpage, bool evict = false);
/** 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((warn_unused_result));
/** 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 a page id.
@param[in] page_id page id
@return buffer pool */
UNIV_INLINE
buf_pool_t *buf_pool_get(const page_id_t &page_id);
/** 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.
@param[in] buf_pool buffer pool instance
@param[in] page_id page id
@return block, NULL if not found */
UNIV_INLINE
buf_page_t *buf_page_hash_get_low(buf_pool_t *buf_pool,
const page_id_t &page_id);
/** 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.
@param[in] buf_pool buffer pool instance
@param[in] page_id page id
@param[in,out] lock 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.
@param[in] lock_mode RW_LOCK_X or RW_LOCK_S. Ignored if
lock == NULL
@param[in] watch if true, return watch sentinel also.
@return pointer to the bpage or NULL; if NULL, lock is also NULL or
a watch sentinel. */
UNIV_INLINE
buf_page_t *buf_page_hash_get_locked(buf_pool_t *buf_pool,
const page_id_t &page_id, rw_lock_t **lock,
ulint lock_mode, bool watch = false);
/** 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.
@param[in] buf_pool buffer pool instance
@param[in] page_id page id
@param[in,out] lock 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.
@param[in] lock_mode RW_LOCK_X or RW_LOCK_S. Ignored if
lock == NULL
@return pointer to the block or NULL; if NULL, lock is also NULL. */
UNIV_INLINE
buf_block_t *buf_block_hash_get_locked(buf_pool_t *buf_pool,
const page_id_t &page_id,
rw_lock_t **lock, ulint lock_mode);
/* 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, page_id, l) \
buf_page_hash_get_locked(b, page_id, l, RW_LOCK_S)
#define buf_page_hash_get_x_locked(b, page_id, l) \
buf_page_hash_get_locked(b, page_id, l, RW_LOCK_X)
#define buf_page_hash_get(b, page_id) \
buf_page_hash_get_locked(b, page_id, NULL, 0)
#define buf_page_get_also_watch(b, page_id) \
buf_page_hash_get_locked(b, page_id, NULL, 0, true)
#define buf_block_hash_get_s_locked(b, page_id, l) \
buf_block_hash_get_locked(b, page_id, l, RW_LOCK_S)
#define buf_block_hash_get_x_locked(b, page_id, l) \
buf_block_hash_get_locked(b, page_id, l, RW_LOCK_X)
#define buf_block_hash_get(b, page_id) \
buf_block_hash_get_locked(b, page_id, NULL, 0)
/** Gets the current length of the free list of buffer blocks.
@return length of the free list */
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 */
ibool buf_pool_watch_is_sentinel(
const buf_pool_t *buf_pool, /*!< buffer pool instance */
const buf_page_t *bpage) /*!< in: block */
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.
@param[in] page_id page id */
void buf_pool_watch_unset(const page_id_t &page_id);
/** 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).
@param[in] page_id page id
@return false if the given page was not read in, true if it was */
ibool buf_pool_watch_occurred(const page_id_t &page_id)
MY_ATTRIBUTE((warn_unused_result));
/** Get total buffer pool statistics. */
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. */
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. */
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.
@param[in] buf_pool buffer pool instance
@param[in] n nth chunk in the buffer pool
@param[in] chunk_size chunk_size
@return the nth chunk's buffer block. */
UNIV_INLINE
buf_block_t *buf_get_nth_chunk_block(const buf_pool_t *buf_pool, ulint n,
ulint *chunk_size);
/** Verify the possibility that a stored page is not in buffer pool.
@param[in] withdraw_clock withdraw clock when stored the page
@retval true if the page might be relocated */
UNIV_INLINE
bool buf_pool_is_obsolete(ulint withdraw_clock);
/** Calculate aligned buffer pool size based on srv_buf_pool_chunk_unit,
if needed.
@param[in] size size in bytes
@return aligned size */
UNIV_INLINE
ulint buf_pool_size_align(ulint size);
/** Adjust the proposed chunk unit size so that it satisfies all invariants
@param[in] size proposed size of buffer pool chunk unit in bytes
@return adjusted size which meets invariants */
ulonglong buf_pool_adjust_chunk_unit(ulonglong size);
/** Calculate the checksum of a page from compressed table and update the
page.
@param[in,out] page page to update
@param[in] size compressed page size
@param[in] lsn LSN to stamp on the page
@param[in] skip_lsn_check true to skip check for lsn (in DEBUG) */
void buf_flush_update_zip_checksum(buf_frame_t *page, ulint size, lsn_t lsn,
bool skip_lsn_check);
#endif /* !UNIV_HOTBACKUP */
/** Return how many more pages must be added to the withdraw list to reach the
withdraw target of the currently ongoing buffer pool resize.
@param[in] buf_pool buffer pool instance
@return page count to be withdrawn or zero if the target is already achieved or
if the buffer pool is not currently being resized. */
UNIV_INLINE
ulint buf_get_withdraw_depth(buf_pool_t *buf_pool);
/** Gets the io_fix state of a buffer 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.
@param[in] block pointer to the buffer block
@return page io_fix state */
UNIV_INLINE
buf_io_fix buf_block_get_io_fix_unlocked(const buf_block_t *block)
MY_ATTRIBUTE((warn_unused_result));
/** Gets the io_fix state of a buffer page. 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.
@param[in] bpage pointer to the buffer page
@return page io_fix state */
UNIV_INLINE
enum buf_io_fix buf_page_get_io_fix_unlocked(const buf_page_t *bpage)
MY_ATTRIBUTE((warn_unused_result));
/** 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
class buf_page_t {
public:
/** @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. */
/* @{ */
/** Page id. */
page_id_t id;
/** Page size. */
page_size_t size;
/** Count of how manyfold this block is currently bufferfixed. */
uint32_t buf_fix_count;
/** type of pending I/O operation. */
buf_io_fix io_fix;
/** Block state. @see buf_page_in_file */
buf_page_state state;
/** if this block is currently being flushed to disk, this tells
the flush_type. @see buf_flush_t */
unsigned flush_type : 2;
/** index number of the buffer pool that this block belongs to */
unsigned buf_pool_index : 6;
static_assert(MAX_BUFFER_POOLS <= 64,
"MAX_BUFFER_POOLS > 64; redefine buf_pool_index");
/* @} */
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 */
#endif /* !UNIV_HOTBACKUP */
#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
All these are protected by buf_pool->mutex. */
/* @{ */
UT_LIST_NODE_T(buf_page_t) list;
/*!< based on state, this is a
list node, protected by the
corresponding list mutex, in one of the
following lists in buf_pool:
- BUF_BLOCK_NOT_USED: free, withdraw
- BUF_BLOCK_FILE_PAGE: flush_list
- BUF_BLOCK_ZIP_DIRTY: flush_list
- BUF_BLOCK_ZIP_PAGE: zip_clean
The node pointers are protected by the
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 */
FlushObserver *flush_observer; /*!< flush observer */
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
These fields are protected by both buf_pool->LRU_list_mutex and the
block mutex. */
/* @{ */
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 */
#ifndef UNIV_HOTBACKUP
unsigned old : 1; /*!< TRUE if the block is in the old
blocks in buf_pool->LRU_old */
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 */
#ifdef 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 */
#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
BPageLock lock; /*!< read-write lock of the buffer
frame */
#endif /* 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. Protected by
both LRU_list_mutex and the block
mutex. */
#ifdef UNIV_DEBUG
ibool in_unzip_LRU_list; /*!< TRUE if the page is in the
decompressed LRU list;
used in debugging */
ibool in_withdraw_list;
#endif /* UNIV_DEBUG */
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()) */
/* @} */
/** @name Optimistic search field */
/* @{ */
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, or (3) the block
must belong to an intrinsic table */
/* @} */
/** @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 */
volatile ulint n_bytes; /*!< recommended prefix length for hash
search: number of bytes in
an incomplete last field */
volatile ulint n_fields; /*!< recommended prefix length for hash
search: number of full fields */
volatile bool 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 are holding the appropriate x-latch in btr_search_latches[], and
one of the following holds:
(1) the block state is BUF_BLOCK_FILE_PAGE, and
we are holding an s-latch or x-latch on buf_block_t::lock, or
(2) buf_block_t::buf_fix_count == 0, or
(3) the block state is BUF_BLOCK_REMOVE_HASH.
An exception to this is when we init or create a page
in the buffer pool in buf0buf.cc.
Another exception for buf_pool_clear_hash_index() is that
assigning block->index = NULL (and block->n_pointers = 0)
is allowed whenever btr_search_own_all(RW_LOCK_X).
Another exception is that ha_insert_for_fold_func() may
decrement n_pointers without holding the appropriate latch
in btr_search_latches[]. Thus, n_pointers must be
protected by atomic memory access.
This implies that the fields may be read without race
condition whenever any of the following hold:
- the btr_search_latches[] s-latch or x-latch is being held, or
- the block state is not BUF_BLOCK_FILE_PAGE or BUF_BLOCK_REMOVE_HASH,
and holding some latch prevents the state from changing to that.
Some use of assert_block_ahi_empty() or assert_block_ahi_valid()
is prone to race conditions while buf_pool_clear_hash_index() is
executing (the adaptive hash index is being disabled). Such use
is explicitly commented. */
/* @{ */
#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;
protected by atomic memory access
or btr_search_own_all(). */
#define assert_block_ahi_empty(block) \
ut_a(os_atomic_increment_ulint(&(block)->n_pointers, 0) == 0)
#define assert_block_ahi_empty_on_init(block) \
do { \
UNIV_MEM_VALID(&(block)->n_pointers, sizeof(block)->n_pointers); \
assert_block_ahi_empty(block); \
} while (0)
#define assert_block_ahi_valid(block) \
ut_a((block)->index || \
os_atomic_increment_ulint(&(block)->n_pointers, 0) == 0)
#else /* UNIV_AHI_DEBUG || UNIV_DEBUG */
#define assert_block_ahi_empty(block) /* nothing */
#define assert_block_ahi_empty_on_init(block) /* nothing */
#define assert_block_ahi_valid(block) /* nothing */
#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. */
/* @} */
bool made_dirty_with_no_latch;
/*!< true if block has been made dirty
without acquiring X/SX latch as the
block belongs to temporary tablespace
and block is always accessed by a
single thread. */
#ifndef UNIV_HOTBACKUP
#ifdef UNIV_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 /* UNIV_DEBUG */
#endif /* !UNIV_HOTBACKUP */
BPageMutex mutex; /*!< mutex protecting this block:
state (also protected by the buffer
pool mutex), io_fix, buf_fix_count,
and accessed; we introduce this new
mutex in InnoDB-5.1 to relieve
contention on the buffer pool mutex */
/** Get the page number of the current buffer block.
@return page number of the current buffer block. */
page_no_t get_page_no() const { return (page.id.page_no()); }
/** Get the next page number of the current buffer block.
@return next page number of the current buffer block. */
page_no_t get_next_page_no() const {
return (mach_read_from_4(frame + FIL_PAGE_NEXT));
}
/** Get the page type of the current buffer block.
@return page type of the current buffer block. */
page_type_t get_page_type() const {
return (mach_read_from_2(frame + FIL_PAGE_TYPE));
}
/** Get the page type of the current buffer block as string.
@return page type of the current buffer block as string. */
const char *get_page_type_str() const;
lizard::Cache_tcn *cache_tcn;
};
/** 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))
/** 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))
/* @} */
/** A "Hazard Pointer" class used to iterate over page lists
inside the buffer pool. A hazard pointer is a buf_page_t pointer
which we intend to iterate over next and we want it remain valid
even after we release the buffer pool mutex. */
class HazardPointer {
public:
/** Constructor
@param buf_pool buffer pool instance
@param mutex mutex that is protecting the hp. */
HazardPointer(const buf_pool_t *buf_pool, const ib_mutex_t *mutex)
: m_buf_pool(buf_pool)
#ifdef UNIV_DEBUG
,
m_mutex(mutex)
#endif /* UNIV_DEBUG */
,
m_hp() {
}
/** Destructor */
virtual ~HazardPointer() {}
/** Get current value */
buf_page_t *get() const {
ut_ad(mutex_own(m_mutex));
return (m_hp);
}
/** Set current value
@param bpage buffer block to be set as hp */
void set(buf_page_t *bpage);
/** Checks if a bpage is the hp
@param bpage buffer block to be compared
@return true if it is hp */
bool is_hp(const buf_page_t *bpage);
/** Adjust the value of hp. This happens when some
other thread working on the same list attempts to
remove the hp from the list. Must be implemented
by the derived classes.
@param bpage buffer block to be compared */
virtual void adjust(const buf_page_t *bpage) = 0;
protected:
/** Disable copying */
HazardPointer(const HazardPointer &);
HazardPointer &operator=(const HazardPointer &);
/** Buffer pool instance */
const buf_pool_t *m_buf_pool;
#ifdef UNIV_DEBUG
/** mutex that protects access to the m_hp. */
const ib_mutex_t *m_mutex;
#endif /* UNIV_DEBUG */
/** hazard pointer. */
buf_page_t *m_hp;
};
/** Class implementing buf_pool->flush_list hazard pointer */
class FlushHp : public HazardPointer {
public:
/** Constructor
@param buf_pool buffer pool instance
@param mutex mutex that is protecting the hp. */
FlushHp(const buf_pool_t *buf_pool, const ib_mutex_t *mutex)
: HazardPointer(buf_pool, mutex) {}
/** Destructor */
virtual ~FlushHp() {}
/** Adjust the value of hp. This happens when some
other thread working on the same list attempts to
remove the hp from the list.
@param bpage buffer block to be compared */
void adjust(const buf_page_t *bpage);
};
/** Class implementing buf_pool->LRU hazard pointer */
class LRUHp : public HazardPointer {
public:
/** Constructor
@param buf_pool buffer pool instance
@param mutex mutex that is protecting the hp. */
LRUHp(const buf_pool_t *buf_pool, const ib_mutex_t *mutex)
: HazardPointer(buf_pool, mutex) {}
/** Destructor */
virtual ~LRUHp() {}
/** Adjust the value of hp. This happens when some
other thread working on the same list attempts to
remove the hp from the list.
@param bpage buffer block to be compared */
void adjust(const buf_page_t *bpage);
};
/** Special purpose iterators to be used when scanning the LRU list.
The idea is that when one thread finishes the scan it leaves the
itr in that position and the other thread can start scan from
there */
class LRUItr : public LRUHp {
public:
/** Constructor
@param buf_pool buffer pool instance
@param mutex mutex that is protecting the hp. */
LRUItr(const buf_pool_t *buf_pool, const ib_mutex_t *mutex)
: LRUHp(buf_pool, mutex) {}
/** Destructor */
virtual ~LRUItr() {}
/** Selects from where to start a scan. If we have scanned
too deep into the LRU list it resets the value to the tail
of the LRU list.
@return buf_page_t from where to start scan. */
buf_page_t *start();
};
/** 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; this field
is NOT protected by the buffer
pool mutex */
ulint n_pages_read; /*!< number of read operations. Accessed
atomically. */
ulint n_pages_written; /*!< number of write operations. Accessed
atomically. */
ulint n_pages_created; /*!< number of pages created
in the pool with no read. Accessed
atomically. */
ulint n_ra_pages_read_rnd; /*!< number of pages read in
as part of random read ahead. Not protected. */
ulint n_ra_pages_read; /*!< number of pages read in
as part of read ahead. Not protected. */
ulint n_ra_pages_evicted; /*!< number of read ahead
pages that are evicted without
being accessed. Protected by LRU_list_mutex. */
ulint n_pages_made_young; /*!< number of pages made young, in
calls to buf_LRU_make_block_young(). Protected
by LRU_list_mutex. */
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(). Not protected. */
ulint LRU_bytes; /*!< LRU size in bytes. Protected by
LRU_list_mutex. */
ulint flush_list_bytes; /*!< flush_list size in bytes.
Protected by flush_list_mutex */
};
/** 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. */
uint64_t relocated;
/** Total duration of block relocations, in microseconds. */
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 */
/* @{ */
BufListMutex chunks_mutex; /*!< protects (de)allocation of chunks:
- changes to chunks, n_chunks are performed
while holding this latch,
- reading buf_pool_should_madvise requires
holding this latch for any buf_pool_t
- writing to buf_pool_should_madvise requires
holding these latches for all buf_pool_t-s
*/
BufListMutex LRU_list_mutex; /*!< LRU list mutex */
BufListMutex free_list_mutex; /*!< free and withdraw list mutex */
BufListMutex zip_free_mutex; /*!< buddy allocator mutex */
BufListMutex zip_hash_mutex; /*!< zip_hash mutex */
ib_mutex_t flush_state_mutex; /*!< Flush state protection
mutex */
BufPoolZipMutex zip_mutex; /*!< Zip mutex of this buffer
pool instance, protects compressed
only pages (of type buf_page_t, not
buf_block_t */
ulint instance_no; /*!< Array index of this buffer
pool instance */
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.
Protected by zip_hash_mutex. */
#endif
ut_allocator<unsigned char> allocator; /*!< Allocator used for
allocating memory for the the "chunks"
member. */
volatile ulint n_chunks; /*!< number of buffer pool chunks */
volatile ulint n_chunks_new; /*!< new number of buffer pool chunks */
buf_chunk_t *chunks; /*!< buffer pool chunks */
buf_chunk_t *chunks_old; /*!< old buffer pool chunks to be freed
after resizing buffer pool */
ulint curr_size; /*!< current pool size in pages */
ulint old_size; /*!< previous pool size in pages */
page_no_t 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 *page_hash_old; /*!< old pointer to page_hash to be
freed after resizing buffer pool */
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.
Accessed atomically. */
ib_time_monotonic_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, except for the used
field, which is also accessed
atomically */
buf_pool_stat_t stat; /*!< current statistics */
buf_pool_stat_t old_stat; /*!< old statistics */
/* @} */
/** @name Page flushing algorithm fields */
/* @{ */
BufListMutex 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 */
FlushHp flush_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. Protected by
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 protected by
memory barriers. */
lsn_t track_page_lsn; /* Pagge Tracking start LSN. */
lsn_t max_lsn_io; /* Maximum LSN for which write io
has already started. */
/* @} */
/** @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) withdraw;
/*!< base node of the withdraw
block list. It is only used during
shrinking buffer pool size, not to
reuse the blocks will be removed.
Protected by free_list_mutex */
ulint withdraw_target; /*!< target length of withdraw
block list, when withdrawing */
/** "hazard pointer" used during scan of LRU while doing
LRU list batch. Protected by buf_pool::LRU_list_mutex */
LRUHp lru_hp;
/** Iterator used to scan the LRU list when searching for
replacable victim. Protected by buf_pool::LRU_list_mutex. */
LRUItr lru_scan_itr;
/** Iterator used to scan the LRU list when searching for
single page flushing victim. Protected by buf_pool::LRU_list_mutex. */
LRUItr single_scan_itr;
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. Scanning the array is
protected by taking all page_hash
latches in X. Updating or reading an
individual watch page is protected by
a corresponding individual page_hash
latch. */
/** A wrapper for buf_pool_t::allocator.alocate_large which also advices the
OS that this chunk should not be dumped to a core file if that was requested.
Emits a warning to the log and disables @@global.core_file if advising was
requested but could not be performed, but still return true as the allocation
itself succeeded.
@param[in] mem_size number of bytes to allocate
@param[in,out] chunk mem and mem_pfx fields of this chunk will be updated
to contain information about allocated memory region
@return true iff allocated successfully */
bool allocate_chunk(ulonglong mem_size, buf_chunk_t *chunk);
/** A wrapper for buf_pool_t::allocator.deallocate_large which also advices
the OS that this chunk can be dumped to a core file.
Emits a warning to the log and disables @@global.core_file if advising was
requested but could not be performed.
@param[in] chunk mem and mem_pfx fields of this chunk will be used to
locate the memory region to free */
void deallocate_chunk(buf_chunk_t *chunk);
/** Advices the OS that all chunks in this buffer pool instance can be dumped
to a core file.
Emits a warning to the log if could not succeed.
@return true iff succeeded, false if no OS support or failed */
bool madvise_dump();
/** Advices the OS that all chunks in this buffer pool instance should not
be dumped to a core file.
Emits a warning to the log if could not succeed.
@return true iff succeeded, false if no OS support or failed */
bool madvise_dont_dump();
#if BUF_BUDDY_LOW > UNIV_ZIP_SIZE_MIN
#error "BUF_BUDDY_LOW > UNIV_ZIP_SIZE_MIN"
#endif
/* @} */
};
/** Print the given buf_pool_t object.
@param[in,out] out the output stream
@param[in] buf_pool the buf_pool_t object to be printed
@return the output stream */
std::ostream &operator<<(std::ostream &out, const buf_pool_t &buf_pool);
/** @name Accessors for buffer pool mutexes
Use these instead of accessing buffer pool mutexes directly. */
/* @{ */
#ifndef UNIV_HOTBACKUP
/** 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_page_mutex_own(b) (b)->mutex.is_owned()
/** Acquire the block->mutex. */
#define buf_page_mutex_enter(b) \
do { \
mutex_enter(&(b)->mutex); \
} while (0)
/** Release the block->mutex. */
#define buf_page_mutex_exit(b) \
do { \
(b)->mutex.exit(); \
} while (0)
/** Get appropriate page_hash_lock. */
#define buf_page_hash_lock_get(buf_pool, page_id) \
hash_get_lock((buf_pool)->page_hash, (page_id).fold())
/** If not appropriate page_hash_lock, relock until appropriate. */
#define buf_page_hash_lock_s_confirm(hash_lock, buf_pool, page_id) \
hash_lock_s_confirm(hash_lock, (buf_pool)->page_hash, (page_id).fold())
#define buf_page_hash_lock_x_confirm(hash_lock, buf_pool, page_id) \
hash_lock_x_confirm(hash_lock, (buf_pool)->page_hash, (page_id).fold())
#endif /* !UNIV_HOTBACKUP */
#if defined(UNIV_DEBUG) && !defined(UNIV_HOTBACKUP)
/** Test if page_hash lock is held in s-mode. */
#define buf_page_hash_lock_held_s(buf_pool, bpage) \
rw_lock_own(buf_page_hash_lock_get((buf_pool), (bpage)->id), RW_LOCK_S)
/** Test if page_hash lock is held in x-mode. */
#define buf_page_hash_lock_held_x(buf_pool, bpage) \
rw_lock_own(buf_page_hash_lock_get((buf_pool), (bpage)->id), RW_LOCK_X)
/** Test if page_hash lock is held in x or s-mode. */
#define buf_page_hash_lock_held_s_or_x(buf_pool, bpage) \
(buf_page_hash_lock_held_s((buf_pool), (bpage)) || \
buf_page_hash_lock_held_x((buf_pool), (bpage)))
#define buf_block_hash_lock_held_s(buf_pool, block) \
buf_page_hash_lock_held_s((buf_pool), &(block)->page)
#define buf_block_hash_lock_held_x(buf_pool, block) \
buf_page_hash_lock_held_x((buf_pool), &(block)->page)
#define buf_block_hash_lock_held_s_or_x(buf_pool, block) \
buf_page_hash_lock_held_s_or_x((buf_pool), &(block)->page)
#else /* UNIV_DEBUG && !UNIV_HOTBACKUP */
#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_DEBUG && !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
#ifndef UNIV_HOTBACKUP
/** Functor to validate the LRU list. */
struct CheckInLRUList {
void operator()(const buf_page_t *elem) const { ut_a(elem->in_LRU_list); }
static void validate(const buf_pool_t *buf_pool) {
CheckInLRUList check;
ut_list_validate(buf_pool->LRU, check);
}
};
/** Functor to validate the LRU list. */
struct CheckInFreeList {
void operator()(const buf_page_t *elem) const { ut_a(elem->in_free_list); }
static void validate(const buf_pool_t *buf_pool) {
CheckInFreeList check;
ut_list_validate(buf_pool->free, check);
}
};
struct CheckUnzipLRUAndLRUList {
void operator()(const buf_block_t *elem) const {
ut_a(elem->page.in_LRU_list);
ut_a(elem->in_unzip_LRU_list);
}
static void validate(const buf_pool_t *buf_pool) {
CheckUnzipLRUAndLRUList check;
ut_list_validate(buf_pool->unzip_LRU, check);
}
};
#endif /* !UNIV_HOTBACKUP */
#endif /* UNIV_DEBUG || defined UNIV_BUF_DEBUG */
#include "buf0buf.ic"
namespace lizard {
void allocate_block_tcn(buf_block_t *block);
void deallocate_block_tcn(buf_block_t *block);
} // namespace lizard
#endif /* !buf0buf_h */
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