mariadb/storage/innobase/include/buf0flu.h

247 lines
9.2 KiB
C

/*****************************************************************************
Copyright (c) 1995, 2011, 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 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/buf0flu.h
The database buffer pool flush algorithm
Created 11/5/1995 Heikki Tuuri
*******************************************************/
#ifndef buf0flu_h
#define buf0flu_h
#include "univ.i"
#include "ut0byte.h"
#include "log0log.h"
#ifndef UNIV_HOTBACKUP
#include "mtr0types.h"
#include "buf0types.h"
/** Flag indicating if the page_cleaner is in active state. */
extern ibool buf_page_cleaner_is_active;
/********************************************************************//**
Remove a block from the flush list of modified blocks. */
UNIV_INTERN
void
buf_flush_remove(
/*=============*/
buf_page_t* bpage); /*!< in: pointer to the block in question */
/*******************************************************************//**
Relocates a buffer control block on the flush_list.
Note that it is assumed that the contents of bpage has already been
copied to dpage. */
UNIV_INTERN
void
buf_flush_relocate_on_flush_list(
/*=============================*/
buf_page_t* bpage, /*!< in/out: control block being moved */
buf_page_t* dpage); /*!< in/out: destination block */
/********************************************************************//**
Updates the flush system data structures when a write is completed. */
UNIV_INTERN
void
buf_flush_write_complete(
/*=====================*/
buf_page_t* bpage); /*!< in: pointer to the block in question */
#endif /* !UNIV_HOTBACKUP */
/********************************************************************//**
Initializes a page for writing to the tablespace. */
UNIV_INTERN
void
buf_flush_init_for_writing(
/*=======================*/
byte* page, /*!< in/out: page */
void* page_zip_, /*!< in/out: compressed page, or NULL */
lsn_t newest_lsn); /*!< in: newest modification lsn
to the page */
#ifndef UNIV_HOTBACKUP
# if defined UNIV_DEBUG || defined UNIV_IBUF_DEBUG
/********************************************************************//**
Writes a flushable page asynchronously from the buffer pool to a file.
NOTE: buf_pool->mutex and block->mutex must be held upon entering this
function, and they will be released by this function after flushing.
This is loosely based on buf_flush_batch() and buf_flush_page().
@return TRUE if the page was flushed and the mutexes released */
UNIV_INTERN
ibool
buf_flush_page_try(
/*===============*/
buf_pool_t* buf_pool, /*!< in/out: buffer pool instance */
buf_block_t* block) /*!< in/out: buffer control block */
__attribute__((nonnull, warn_unused_result));
# endif /* UNIV_DEBUG || UNIV_IBUF_DEBUG */
/********************************************************************//**
Flush a batch of writes to the datafiles that have already been
written by the OS. */
UNIV_INTERN
void
buf_flush_sync_datafiles(void);
/*==========================*/
/*******************************************************************//**
This utility flushes dirty blocks from the end of the flush_list of
all buffer pool instances.
NOTE: The calling thread is not allowed to own any latches on pages!
@return number of blocks for which the write request was queued;
ULINT_UNDEFINED if there was a flush of the same type already running */
UNIV_INTERN
ulint
buf_flush_list(
/*============*/
ulint min_n, /*!< in: wished minimum mumber of blocks
flushed (it is not guaranteed that the
actual number is that big, though) */
lsn_t lsn_limit); /*!< in the case BUF_FLUSH_LIST all
blocks whose oldest_modification is
smaller than this should be flushed
(if their number does not exceed
min_n), otherwise ignored */
/******************************************************************//**
This function picks up a single dirty page from the tail of the LRU
list, flushes it, removes it from page_hash and LRU list and puts
it on the free list. It is called from user threads when they are
unable to find a replacable page at the tail of the LRU list i.e.:
when the background LRU flushing in the page_cleaner thread is not
fast enough to keep pace with the workload.
@return TRUE if success. */
UNIV_INTERN
ibool
buf_flush_single_page_from_LRU(
/*===========================*/
buf_pool_t* buf_pool); /*!< in/out: buffer pool instance */
/******************************************************************//**
Waits until a flush batch of the given type ends */
UNIV_INTERN
void
buf_flush_wait_batch_end(
/*=====================*/
buf_pool_t* buf_pool, /*!< in: buffer pool instance */
enum buf_flush type); /*!< in: BUF_FLUSH_LRU
or BUF_FLUSH_LIST */
/******************************************************************//**
Waits until a flush batch of the given type ends. This is called by
a thread that only wants to wait for a flush to end but doesn't do
any flushing itself. */
UNIV_INTERN
void
buf_flush_wait_batch_end_wait_only(
/*===============================*/
buf_pool_t* buf_pool, /*!< in: buffer pool instance */
enum buf_flush type); /*!< in: BUF_FLUSH_LRU
or BUF_FLUSH_LIST */
/********************************************************************//**
This function should be called at a mini-transaction commit, if a page was
modified in it. Puts the block to the list of modified blocks, if it not
already in it. */
UNIV_INLINE
void
buf_flush_note_modification(
/*========================*/
buf_block_t* block, /*!< in: block which is modified */
mtr_t* mtr); /*!< in: mtr */
/********************************************************************//**
This function should be called when recovery has modified a buffer page. */
UNIV_INLINE
void
buf_flush_recv_note_modification(
/*=============================*/
buf_block_t* block, /*!< in: block which is modified */
lsn_t start_lsn, /*!< in: start lsn of the first mtr in a
set of mtr's */
lsn_t end_lsn); /*!< in: end lsn of the last mtr in the
set of mtr's */
/********************************************************************//**
Returns TRUE if the file page block is immediately suitable for replacement,
i.e., transition FILE_PAGE => NOT_USED allowed.
@return TRUE if can replace immediately */
UNIV_INTERN
ibool
buf_flush_ready_for_replace(
/*========================*/
buf_page_t* bpage); /*!< in: buffer control block, must be
buf_page_in_file(bpage) and in the LRU list */
/** @brief Statistics for selecting flush rate based on redo log
generation speed.
These statistics are generated for heuristics used in estimating the
rate at which we should flush the dirty blocks to avoid bursty IO
activity. Note that the rate of flushing not only depends on how many
dirty pages we have in the buffer pool but it is also a fucntion of
how much redo the workload is generating and at what rate. */
struct buf_flush_stat_struct
{
lsn_t redo; /**< amount of redo generated. */
ulint n_flushed; /**< number of pages flushed. */
};
/** Statistics for selecting flush rate of dirty pages. */
typedef struct buf_flush_stat_struct buf_flush_stat_t;
/*********************************************************************
Update the historical stats that we are collecting for flush rate
heuristics at the end of each interval. */
UNIV_INTERN
void
buf_flush_stat_update(void);
/*=======================*/
/******************************************************************//**
page_cleaner thread tasked with flushing dirty pages from the buffer
pools. As of now we'll have only one instance of this thread.
@return a dummy parameter */
extern "C" UNIV_INTERN
os_thread_ret_t
DECLARE_THREAD(buf_flush_page_cleaner_thread)(
/*==========================================*/
void* arg); /*!< in: a dummy parameter required by
os_thread_create */
#if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
/******************************************************************//**
Validates the flush list.
@return TRUE if ok */
UNIV_INTERN
ibool
buf_flush_validate(
/*===============*/
buf_pool_t* buf_pool);
#endif /* UNIV_DEBUG || UNIV_BUF_DEBUG */
/********************************************************************//**
Initialize the red-black tree to speed up insertions into the flush_list
during recovery process. Should be called at the start of recovery
process before any page has been read/written. */
UNIV_INTERN
void
buf_flush_init_flush_rbt(void);
/*==========================*/
/********************************************************************//**
Frees up the red-black tree. */
UNIV_INTERN
void
buf_flush_free_flush_rbt(void);
/*==========================*/
#endif /* !UNIV_HOTBACKUP */
#ifndef UNIV_NONINL
#include "buf0flu.ic"
#endif
#endif