#include "univ.i"
#include "ut0byte.h"
#include "log0log.h"
#include "mtr0types.h"
#include "buf0types.h"
#include "buf0flu.ic"

Include dependency graph for buf0flu.h:

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Functions
UNIV_INTERN void	buf_flush_remove (buf_page_t *bpage)
UNIV_INTERN void	buf_flush_relocate_on_flush_list (buf_page_t bpage, buf_page_t dpage)
UNIV_INTERN void	buf_flush_write_complete (buf_page_t *bpage)
UNIV_INTERN void	buf_flush_init_for_writing (byte page, void page_zip_, lsn_t newest_lsn)
UNIV_INTERN ibool	buf_flush_page_try (buf_pool_t buf_pool, buf_block_t block))
UNIV_INTERN bool	buf_flush_list (ulint min_n, lsn_t lsn_limit, ulint *n_processed)
UNIV_INTERN ibool	buf_flush_single_page_from_LRU (buf_pool_t *buf_pool)
UNIV_INTERN void	buf_flush_wait_batch_end (buf_pool_t *buf_pool, buf_flush_t type)
UNIV_INTERN void	buf_flush_wait_batch_end_wait_only (buf_pool_t *buf_pool, buf_flush_t type)
UNIV_INLINE void	buf_flush_note_modification (buf_block_t block, mtr_t mtr)
UNIV_INLINE void	buf_flush_recv_note_modification (buf_block_t *block, lsn_t start_lsn, lsn_t end_lsn)
UNIV_INTERN ibool	buf_flush_ready_for_replace (buf_page_t *bpage)
UNIV_INTERN os_thread_ret_t DECLARE_THREAD()	buf_flush_page_cleaner_thread (void *arg)
UNIV_INTERN ulint	buf_flush_LRU_tail (void)
UNIV_INTERN void	buf_flush_wait_LRU_batch_end (void)
UNIV_INTERN ibool	buf_flush_validate (buf_pool_t *buf_pool)
UNIV_INTERN void	buf_flush_init_flush_rbt (void)
UNIV_INTERN void	buf_flush_free_flush_rbt (void)
UNIV_INTERN bool	buf_flush_page (buf_pool_t buf_pool, buf_page_t bpage, buf_flush_t flush_type, bool sync)
UNIV_INTERN bool	buf_flush_ready_for_flush (buf_page_t *bpage, buf_flush_t flush_type))
UNIV_INTERN ulint	buf_pool_get_dirty_pages_count (buf_pool_t *buf_pool, ulint id)
UNIV_INTERN ulint	buf_flush_get_dirty_pages_count (ulint id)

Variables
ibool	buf_page_cleaner_is_active

Detailed Description

The database buffer pool flush algorithm

Created 11/5/1995 Heikki Tuuri

Function Documentation

UNIV_INTERN void buf_flush_free_flush_rbt ( void )

Frees up the red-black tree.

UNIV_INTERN ulint buf_flush_get_dirty_pages_count ( ulint id )

Check if there are any dirty pages that belong to a space id in the flush list.

Returns: count of dirty pages present in all the buffer pools in: space id to check

UNIV_INTERN void buf_flush_init_flush_rbt ( void )

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_for_writing	(	byte *	page,
		void *	page_zip_,
		lsn_t	newest_lsn
	)

Initializes a page for writing to the tablespace. in: newest modification lsn to the page

Parameters

page	in/out: page
page_zip_	in/out: compressed page, or NULL

UNIV_INTERN bool buf_flush_list	(	ulint	min_n,
		lsn_t	lsn_limit,
		ulint *	n_processed
	)

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!

Returns: true if a batch was queued successfully for each buffer pool instance. false if another batch of same type was already running in at least one of the buffer pool instance out: the number of pages which were processed is passed back to caller. Ignored if NULL

Parameters

min_n	in: wished minimum mumber of blocks flushed (it is not guaranteed that the actual number is that big, though)
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

UNIV_INTERN ulint buf_flush_LRU_tail ( void )

Clears up tail of the LRU lists: Put replaceable pages at the tail of LRU to the free list Flush dirty pages at the tail of LRU to the disk The depth to which we scan each buffer pool is controlled by dynamic config parameter innodb_LRU_scan_depth.

Returns: total pages flushed

UNIV_INLINE void buf_flush_note_modification	(	buf_block_t *	block,
		mtr_t *	mtr
	)

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. in: mtr

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 is not already in it.

Parameters

block	in: block which is modified
mtr	in: mtr

UNIV_INTERN bool buf_flush_page	(	buf_pool_t *	buf_pool,
		buf_page_t *	bpage,
		buf_flush_t	flush_type,
		bool	sync
	)

Writes a flushable page asynchronously from the buffer pool to a file. NOTE: in simulated aio we must call os_aio_simulated_wake_handler_threads after we have posted a batch of writes! NOTE: buf_pool->mutex and buf_page_get_mutex(bpage) must be held upon entering this function, and they will be released by this function if it returns true.

Returns: TRUE if the page was flushed in: true if sync IO request

Parameters

buf_pool	in: buffer pool instance
bpage	in: buffer control block
flush_type	in: type of flush

UNIV_INTERN os_thread_ret_t DECLARE_THREAD() buf_flush_page_cleaner_thread ( void * arg )

page_cleaner thread tasked with flushing dirty pages from the buffer pools. As of now we'll have only one instance of this thread.

Returns: a dummy parameter in: a dummy parameter required by os_thread_create

UNIV_INTERN ibool buf_flush_page_try	(	buf_pool_t *	buf_pool,
		buf_block_t *	block
	)

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().

Returns: TRUE if the page was flushed and the mutexes released

Parameters

buf_pool	in/out: buffer pool instance
block	in/out: buffer control block

UNIV_INTERN bool buf_flush_ready_for_flush	(	buf_page_t *	bpage,
		buf_flush_t	flush_type
	)

Returns true if the block is modified and ready for flushing.

Returns: true if can flush immediately

Parameters

bpage	in: buffer control block, must be buf_page_in_file(bpage)
flush_type	in: type of flush

UNIV_INTERN ibool buf_flush_ready_for_replace ( buf_page_t * bpage )

Returns TRUE if the file page block is immediately suitable for replacement, i.e., transition FILE_PAGE => NOT_USED allowed.

Returns: TRUE if can replace immediately in: buffer control block, must be buf_page_in_file(bpage) and in the LRU list

UNIV_INLINE void buf_flush_recv_note_modification	(	buf_block_t *	block,
		lsn_t	start_lsn,
		lsn_t	end_lsn
	)

This function should be called when recovery has modified a buffer page. in: end lsn of the last mtr in the set of mtr's

This function should be called when recovery has modified a buffer page.

Parameters

block	in: block which is modified
start_lsn	in: start lsn of the first mtr in a set of mtr's
end_lsn	in: end lsn of the last mtr in the set of mtr's

UNIV_INTERN void buf_flush_relocate_on_flush_list	(	buf_page_t *	bpage,
		buf_page_t *	dpage
	)

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. in/out: destination block

Parameters

bpage in/out: control block being moved

UNIV_INTERN void buf_flush_remove ( buf_page_t * bpage )

Remove a block from the flush list of modified blocks. in: pointer to the block in question

UNIV_INTERN ibool buf_flush_single_page_from_LRU ( buf_pool_t * buf_pool )

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.

Returns: TRUE if success. in/out: buffer pool instance

UNIV_INTERN ibool buf_flush_validate ( buf_pool_t * buf_pool )

Validates the flush list.

Returns: TRUE if ok

UNIV_INTERN void buf_flush_wait_batch_end	(	buf_pool_t *	buf_pool,
		buf_flush_t	type
	)

Waits until a flush batch of the given type ends in: BUF_FLUSH_LRU or BUF_FLUSH_LIST

Parameters

buf_pool in: buffer pool instance

UNIV_INTERN void buf_flush_wait_batch_end_wait_only	(	buf_pool_t *	buf_pool,
		buf_flush_t	type
	)

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. in: BUF_FLUSH_LRU or BUF_FLUSH_LIST

Parameters

buf_pool in: buffer pool instance

UNIV_INTERN void buf_flush_wait_LRU_batch_end ( void )

Wait for any possible LRU flushes that are in progress to end.

UNIV_INTERN void buf_flush_write_complete ( buf_page_t * bpage )

Updates the flush system data structures when a write is completed. in: pointer to the block in question

UNIV_INTERN ulint buf_pool_get_dirty_pages_count	(	buf_pool_t *	buf_pool,
		ulint	id
	)

Check if there are any dirty pages that belong to a space id in the flush list in a particular buffer pool.

Returns: number of dirty pages present in a single buffer pool in: space id to check

Parameters

buf_pool in: buffer pool

Variable Documentation

ibool buf_page_cleaner_is_active

Flag indicating if the page_cleaner is in active state.

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation