~drizzle-trunk/drizzle/development

/*****************************************************************************

Copyright (c) 1995, 2010, Innobase Oy. 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

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 "univ.i"

#include "fil0fil.h"

#include "mtr0types.h"

#include "buf0types.h"

#include "hash0hash.h"

#include "ut0byte.h"

#include "page0types.h"

#include "ut0rbt.h"

#ifndef UNIV_HOTBACKUP

#include "os0proc.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_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 */

/* @} */

/** @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. */

/* @} */

extern buf_pool_t*	buf_pool;	/*!< The buffer pool 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 */

#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 */

/** Magic value to use instead of checksums when they are disabled */

#define BUF_NO_CHECKSUM_MAGIC 0xDEADBEEFUL

/** @brief States of a control block

@see buf_page_struct

The enumeration values must be 0..7. */

enum buf_page_state {

	BUF_BLOCK_ZIP_FREE = 0,		/*!< contains a free

					compressed page */

	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 */

};

#ifndef UNIV_HOTBACKUP

/********************************************************************//**

Creates the buffer pool.

@return	own: buf_pool object, NULL if not enough memory or error */

UNIV_INTERN

buf_pool_t*

buf_pool_init(void);

/*===============*/

/********************************************************************//**

Frees the buffer pool at shutdown.  This must not be invoked before

freeing all mutexes. */

UNIV_INTERN

void

buf_pool_free(void);

/*===============*/

/********************************************************************//**

Drops the adaptive hash index.  To prevent a livelock, this function

is only to be called while holding btr_search_latch and while

btr_search_enabled == FALSE. */

UNIV_INTERN

void

buf_pool_drop_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 */

	__attribute__((nonnull));

/********************************************************************//**

Resizes the buffer pool. */

UNIV_INTERN

void

buf_pool_resize(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 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_INLINE

ib_uint64_t

buf_pool_get_oldest_modification(void);

/*==================================*/

/********************************************************************//**

Allocates a buffer block.

@return	own: the allocated block, in state BUF_BLOCK_MEMORY */

UNIV_INLINE

buf_block_t*

buf_block_alloc(

/*============*/

	ulint	zip_size);	/*!< in: compressed page size in bytes,

				or 0 if uncompressed tablespace */

/********************************************************************//**

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 if mode is

				..._GUESS_ON_CLOCK */

	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 kernel 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 kernel 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_GET_NO_LATCH */

	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 ibbackup --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 */

	mtr_t*		mtr);		/*!< in: mtr */

/********************************************************************//**

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 */

/********************************************************************//**

Resets the check_index_page_at_flush field of a page if found in the buffer

pool. */

UNIV_INTERN

void

buf_reset_check_index_page_at_flush(

/*================================*/

	ulint	space,	/*!< in: space id */

	ulint	offset);/*!< in: page number */

#ifdef UNIV_DEBUG_FILE_ACCESSES

/********************************************************************//**

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 */

/********************************************************************//**

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 */

	__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 */

	__attribute__((pure));

/********************************************************************//**

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 */

/********************************************************************//**

Returns the current state of is_hashed of a page. FALSE if the page is

not in the pool. NOTE that this operation does not fix the page in the

pool if it is found there.

@return	TRUE if page hash index is built in search system */

UNIV_INTERN

ibool

buf_page_peek_if_search_hashed(

/*===========================*/

	ulint	space,	/*!< in: space id */

	ulint	offset);/*!< in: page number */

/********************************************************************//**

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

ib_uint64_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

buf_pool 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 */

#else /* !UNIV_HOTBACKUP */

# define buf_block_modify_clock_inc(block) ((void) 0)

#endif /* !UNIV_HOTBACKUP */

/********************************************************************//**

Calculates a page checksum which is stored to the page when it is written

to a file. Note that we must be careful to calculate the same value

on 32-bit and 64-bit architectures.

@return	checksum */

UNIV_INTERN

ulint

buf_calc_page_new_checksum(

/*=======================*/

	const byte*	page);	/*!< in: buffer page */

/********************************************************************//**

In versions < 4.0.14 and < 4.1.1 there was a bug that the checksum only

looked at the first few bytes of the page. This calculates that old

checksum.

NOTE: we must first store the new formula checksum to

FIL_PAGE_SPACE_OR_CHKSUM before calculating and storing this old checksum

because this takes that field as an input!

@return	checksum */

UNIV_INTERN

ulint

buf_calc_page_old_checksum(

/*=======================*/

	const byte*	 page);	/*!< in: buffer page */

/********************************************************************//**

Checks if a page is corrupt.

@return	TRUE if corrupted */

UNIV_INTERN

ibool

buf_page_is_corrupted(

/*==================*/

	const byte*	read_buf,	/*!< in: a database page */

	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 */

	__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(

/*==================*/

	const void*	data);	/*!< in: pointer to compressed page */

#endif /* UNIV_DEBUG */

#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 */

/********************************************************************//**

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 */

/********************************************************************//**

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 ios.

@return	number of pending I/O operations */

UNIV_INTERN

ulint

buf_get_n_pending_ios(void);

/*=======================*/

/*********************************************************************//**

Prints info of the buffer i/o. */

UNIV_INTERN

void

buf_print_io(

/*=========*/

	FILE*	file);	/*!< in: file where to print */

/*********************************************************************//**

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

ulint

buf_get_modified_ratio_pct(void);

/*============================*/

/**********************************************************************//**

Refreshes the statistics used to print per-second averages. */

UNIV_INTERN

void

buf_refresh_io_stats(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	TRUE if there is no pending i/o */

UNIV_INTERN

ibool

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 */

	__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 */

	__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 */

	__attribute__((pure));

/*********************************************************************//**

Gets the mutex of a block.

@return	pointer to mutex protecting bpage */

UNIV_INLINE

mutex_t*

buf_page_get_mutex(

/*===============*/

	const buf_page_t*	bpage)	/*!< in: pointer to control block */

	__attribute__((pure));

/*********************************************************************//**

Get the flush type of a page.

@return	flush type */

UNIV_INLINE

enum buf_flush

buf_page_get_flush_type(

/*====================*/

	const buf_page_t*	bpage)	/*!< in: buffer page */

	__attribute__((pure));

/*********************************************************************//**

Set the flush type of a page. */

UNIV_INLINE

void

buf_page_set_flush_type(

/*====================*/

	buf_page_t*	bpage,		/*!< in: buffer page */

	enum buf_flush	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 */

	__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 */

	__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 */

/********************************************************************//**

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 */

	__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 */

	__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 */

	__attribute__((nonnull, pure));

/*********************************************************************//**

Flag a block accessed. */

UNIV_INLINE

void

buf_page_set_accessed(

/*==================*/

	buf_page_t*	bpage,		/*!< in/out: control block */

	ulint		time_ms)	/*!< in: ut_time_ms() */

	__attribute__((nonnull));

/*********************************************************************//**

Gets the buf_block_t handle of a buffered file block if an uncompressed

page frame exists, or NULL.

@return	control block, or NULL */

UNIV_INLINE

buf_block_t*

buf_page_get_block(

/*===============*/

	buf_page_t*	bpage)	/*!< in: control block, or NULL */

	__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(