buf0lru.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

		} else if (old_len > new_len + BUF_LRU_OLD_TOLERANCE) {

			(buf_pool->LRU_old)->old = FALSE;
			buf_pool->LRU_old = UT_LIST_GET_NEXT(LRU,
							buf_pool->LRU_old);
			buf_pool->LRU_old_len--;
		} else {
			ut_a(buf_pool->LRU_old); /* Check that we did not
						fall out of the LRU list */
			return;
		}
	}
}

/***********************************************************************
Initializes the old blocks pointer in the LRU list. This function should be
called when the LRU list grows to BUF_LRU_OLD_MIN_LEN length. */
static
void
buf_LRU_old_init(void)
/*==================*/
{
	buf_block_t*	block;

	ut_a(UT_LIST_GET_LEN(buf_pool->LRU) == BUF_LRU_OLD_MIN_LEN);

	/* We first initialize all blocks in the LRU list as old and then use
	the adjust function to move the LRU_old pointer to the right
	position */

	block = UT_LIST_GET_FIRST(buf_pool->LRU);

	while (block != NULL) {
		ut_a(block->state == BUF_BLOCK_FILE_PAGE);
	        ut_a(block->in_LRU_list);
		block->old = TRUE;
		block = UT_LIST_GET_NEXT(LRU, block);
	}

	buf_pool->LRU_old = UT_LIST_GET_FIRST(buf_pool->LRU);
	buf_pool->LRU_old_len = UT_LIST_GET_LEN(buf_pool->LRU);
	
	buf_LRU_old_adjust_len();
}	    	

/**********************************************************************
Removes a block from the LRU list. */
UNIV_INLINE
void
buf_LRU_remove_block(
/*=================*/
	buf_block_t*	block)	/* in: control block */
{
	ut_ad(buf_pool);
	ut_ad(block);
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(buf_pool->mutex)));
#endif /* UNIV_SYNC_DEBUG */
		
	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
	ut_a(block->in_LRU_list);

	/* If the LRU_old pointer is defined and points to just this block,
	move it backward one step */

	if (block == buf_pool->LRU_old) {

		/* Below: the previous block is guaranteed to exist, because
		the LRU_old pointer is only allowed to differ by the
		tolerance value from strict 3/8 of the LRU list length. */

		buf_pool->LRU_old = UT_LIST_GET_PREV(LRU, block);
		(buf_pool->LRU_old)->old = TRUE;

		buf_pool->LRU_old_len++;
		ut_a(buf_pool->LRU_old);
	}

	/* Remove the block from the LRU list */
	UT_LIST_REMOVE(LRU, buf_pool->LRU, block);
	block->in_LRU_list = FALSE;

	if (srv_use_awe && block->frame) {
		/* Remove from the list of mapped pages */
		
		UT_LIST_REMOVE(awe_LRU_free_mapped,
					buf_pool->awe_LRU_free_mapped, block);
	}	

	/* If the LRU list is so short that LRU_old not defined, return */
	if (UT_LIST_GET_LEN(buf_pool->LRU) < BUF_LRU_OLD_MIN_LEN) {

		buf_pool->LRU_old = NULL;

		return;
	}

	ut_ad(buf_pool->LRU_old);	

	/* Update the LRU_old_len field if necessary */
	if (block->old) {

		buf_pool->LRU_old_len--;
	}

	/* Adjust the length of the old block list if necessary */
	buf_LRU_old_adjust_len();
}	    	

/**********************************************************************
Adds a block to the LRU list end. */
UNIV_INLINE
void
buf_LRU_add_block_to_end_low(
/*=========================*/
	buf_block_t*	block)	/* in: control block */
{
	buf_block_t*	last_block;
	
	ut_ad(buf_pool);
	ut_ad(block);
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(buf_pool->mutex)));
#endif /* UNIV_SYNC_DEBUG */

	ut_a(block->state == BUF_BLOCK_FILE_PAGE);

	block->old = TRUE;

	last_block = UT_LIST_GET_LAST(buf_pool->LRU);

	if (last_block) {
		block->LRU_position = last_block->LRU_position;
	} else {
		block->LRU_position = buf_pool_clock_tic();
	}			

	ut_a(!block->in_LRU_list);
	UT_LIST_ADD_LAST(LRU, buf_pool->LRU, block);
	block->in_LRU_list = TRUE;

	if (srv_use_awe && block->frame) {
		/* Add to the list of mapped pages */
		
		UT_LIST_ADD_LAST(awe_LRU_free_mapped,
					buf_pool->awe_LRU_free_mapped, block);
	}
	
	if (UT_LIST_GET_LEN(buf_pool->LRU) >= BUF_LRU_OLD_MIN_LEN) {

		buf_pool->LRU_old_len++;
	}

	if (UT_LIST_GET_LEN(buf_pool->LRU) > BUF_LRU_OLD_MIN_LEN) {

		ut_ad(buf_pool->LRU_old);

		/* Adjust the length of the old block list if necessary */

		buf_LRU_old_adjust_len();

	} else if (UT_LIST_GET_LEN(buf_pool->LRU) == BUF_LRU_OLD_MIN_LEN) {

		/* The LRU list is now long enough for LRU_old to become
		defined: init it */

		buf_LRU_old_init();
	}
}	    	

/**********************************************************************
Adds a block to the LRU list. */
UNIV_INLINE
void
buf_LRU_add_block_low(
/*==================*/
	buf_block_t*	block,	/* in: control block */
	ibool		old)	/* in: TRUE if should be put to the old blocks
				in the LRU list, else put to the start; if the
				LRU list is very short, the block is added to
				the start, regardless of this parameter */
{
	ulint	cl;
	
	ut_ad(buf_pool);
	ut_ad(block);
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(buf_pool->mutex)));
#endif /* UNIV_SYNC_DEBUG */

	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
	ut_a(!block->in_LRU_list);

	block->old = old;
	cl = buf_pool_clock_tic();

	if (srv_use_awe && block->frame) {
		/* Add to the list of mapped pages; for simplicity we always
		add to the start, even if the user would have set 'old'
		TRUE */
		
		UT_LIST_ADD_FIRST(awe_LRU_free_mapped,
					buf_pool->awe_LRU_free_mapped, block);
	}

	if (!old || (UT_LIST_GET_LEN(buf_pool->LRU) < BUF_LRU_OLD_MIN_LEN)) {

		UT_LIST_ADD_FIRST(LRU, buf_pool->LRU, block);

		block->LRU_position = cl;		
		block->freed_page_clock = buf_pool->freed_page_clock;
	} else {
		UT_LIST_INSERT_AFTER(LRU, buf_pool->LRU, buf_pool->LRU_old,
								block);
		buf_pool->LRU_old_len++;

		/* We copy the LRU position field of the previous block
		to the new block */

		block->LRU_position = (buf_pool->LRU_old)->LRU_position;
	}

	block->in_LRU_list = TRUE;

	if (UT_LIST_GET_LEN(buf_pool->LRU) > BUF_LRU_OLD_MIN_LEN) {

		ut_ad(buf_pool->LRU_old);

		/* Adjust the length of the old block list if necessary */

		buf_LRU_old_adjust_len();

	} else if (UT_LIST_GET_LEN(buf_pool->LRU) == BUF_LRU_OLD_MIN_LEN) {

		/* The LRU list is now long enough for LRU_old to become
		defined: init it */

		buf_LRU_old_init();
	}	
}	    	

/**********************************************************************
Adds a block to the LRU list. */

void
buf_LRU_add_block(
/*==============*/
	buf_block_t*	block,	/* in: control block */
	ibool		old)	/* in: TRUE if should be put to the old
				blocks in the LRU list, else put to the start;
				if the LRU list is very short, the block is
				added to the start, regardless of this
				parameter */
{
	buf_LRU_add_block_low(block, old);
}

/**********************************************************************
Moves a block to the start of the LRU list. */

void
buf_LRU_make_block_young(
/*=====================*/
	buf_block_t*	block)	/* in: control block */
{
	buf_LRU_remove_block(block);
	buf_LRU_add_block_low(block, FALSE);
}

/**********************************************************************
Moves a block to the end of the LRU list. */

void
buf_LRU_make_block_old(
/*===================*/
	buf_block_t*	block)	/* in: control block */
{
	buf_LRU_remove_block(block);
	buf_LRU_add_block_to_end_low(block);
}

/**********************************************************************
Puts a block back to the free list. */

void
buf_LRU_block_free_non_file_page(
/*=============================*/
	buf_block_t*	block)	/* in: block, must not contain a file page */
{
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(buf_pool->mutex)));
#endif /* UNIV_SYNC_DEBUG */
	ut_ad(block);
	
	ut_a((block->state == BUF_BLOCK_MEMORY)
	      || (block->state == BUF_BLOCK_READY_FOR_USE));

	ut_a(block->n_pointers == 0);
	ut_a(!block->in_free_list);

	block->state = BUF_BLOCK_NOT_USED;

#ifdef UNIV_DEBUG	
	/* Wipe contents of page to reveal possible stale pointers to it */
	memset(block->frame, '\0', UNIV_PAGE_SIZE);
#endif	
	UT_LIST_ADD_FIRST(free, buf_pool->free, block);
	block->in_free_list = TRUE;

	if (srv_use_awe && block->frame) {
		/* Add to the list of mapped pages */
		
		UT_LIST_ADD_FIRST(awe_LRU_free_mapped,
					buf_pool->awe_LRU_free_mapped, block);
	}
}

/**********************************************************************
Takes a block out of the LRU list and page hash table and sets the block
state to BUF_BLOCK_REMOVE_HASH. */
static
void
buf_LRU_block_remove_hashed_page(
/*=============================*/
	buf_block_t*	block)	/* in: block, must contain a file page and
				be in a state where it can be freed; there
				may or may not be a hash index to the page */
{
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(buf_pool->mutex)));
#endif /* UNIV_SYNC_DEBUG */
	ut_ad(block);
	
	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
	ut_a(block->io_fix == 0);
	ut_a(block->buf_fix_count == 0);
	ut_a(ut_dulint_cmp(block->oldest_modification, ut_dulint_zero) == 0);

	buf_LRU_remove_block(block);

	buf_pool->freed_page_clock += 1;

	/* Note that if AWE is enabled the block may not have a frame at all */
	
 	buf_block_modify_clock_inc(block);
		
        if (block != buf_page_hash_get(block->space, block->offset)) {
                fprintf(stderr,
"InnoDB: Error: page %lu %lu not found from the hash table\n",
			(ulong) block->space,
			(ulong) block->offset);
                if (buf_page_hash_get(block->space, block->offset)) {
                        fprintf(stderr,
"InnoDB: From hash table we find block %p of %lu %lu which is not %p\n",
		buf_page_hash_get(block->space, block->offset),
                (ulong) buf_page_hash_get(block->space, block->offset)->space,
                (ulong) buf_page_hash_get(block->space, block->offset)->offset,
		block);
                }

#ifdef UNIV_DEBUG
                buf_print();
                buf_LRU_print();
                buf_validate();
                buf_LRU_validate();
#endif
                ut_a(0);
        }	

	HASH_DELETE(buf_block_t, hash, buf_pool->page_hash,
			buf_page_address_fold(block->space, block->offset),
			block);

	block->state = BUF_BLOCK_REMOVE_HASH;
}

/**********************************************************************
Puts a file page whose has no hash index to the free list. */
static
void
buf_LRU_block_free_hashed_page(
/*===========================*/
	buf_block_t*	block)	/* in: block, must contain a file page and
				be in a state where it can be freed */
{
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(buf_pool->mutex)));
#endif /* UNIV_SYNC_DEBUG */
	ut_a(block->state == BUF_BLOCK_REMOVE_HASH);

	block->state = BUF_BLOCK_MEMORY;

	buf_LRU_block_free_non_file_page(block);
}

#ifdef UNIV_DEBUG
/**************************************************************************
Validates the LRU list. */

ibool
buf_LRU_validate(void)
/*==================*/
{
	buf_block_t*	block;
	ulint		old_len;
	ulint		new_len;
	ulint		LRU_pos;
	
	ut_ad(buf_pool);
	mutex_enter(&(buf_pool->mutex));

	if (UT_LIST_GET_LEN(buf_pool->LRU) >= BUF_LRU_OLD_MIN_LEN) {

		ut_a(buf_pool->LRU_old);
		old_len = buf_pool->LRU_old_len;
		new_len = 3 * (UT_LIST_GET_LEN(buf_pool->LRU) / 8);
		ut_a(old_len >= new_len - BUF_LRU_OLD_TOLERANCE);
		ut_a(old_len <= new_len + BUF_LRU_OLD_TOLERANCE);
	}
		
	UT_LIST_VALIDATE(LRU, buf_block_t, buf_pool->LRU);

	block = UT_LIST_GET_FIRST(buf_pool->LRU);

	old_len = 0;

	while (block != NULL) {

		ut_a(block->state == BUF_BLOCK_FILE_PAGE);

		if (block->old) {
			old_len++;
		}

		if (buf_pool->LRU_old && (old_len == 1)) {
			ut_a(buf_pool->LRU_old == block);
		}

		LRU_pos	= block->LRU_position;

		block = UT_LIST_GET_NEXT(LRU, block);

		if (block) {
			/* If the following assert fails, it may
			not be an error: just the buf_pool clock
			has wrapped around */
			ut_a(LRU_pos >= block->LRU_position);
		}
	}

	if (buf_pool->LRU_old) {
		ut_a(buf_pool->LRU_old_len == old_len);
	} 

	UT_LIST_VALIDATE(free, buf_block_t, buf_pool->free);

	block = UT_LIST_GET_FIRST(buf_pool->free);

	while (block != NULL) {
		ut_a(block->state == BUF_BLOCK_NOT_USED);

		block = UT_LIST_GET_NEXT(free, block);
	}

	mutex_exit(&(buf_pool->mutex));
	return(TRUE);
}

/**************************************************************************
Prints the LRU list. */

void
buf_LRU_print(void)
/*===============*/
{
	buf_block_t*	block;
	buf_frame_t*	frame;
	ulint		len;
	
	ut_ad(buf_pool);
	mutex_enter(&(buf_pool->mutex));

	fprintf(stderr, "Pool ulint clock %lu\n", (ulong) buf_pool->ulint_clock);

	block = UT_LIST_GET_FIRST(buf_pool->LRU);

	len = 0;

	while (block != NULL) {

		fprintf(stderr, "BLOCK %lu ", (ulong) block->offset);

		if (block->old) {
			fputs("old ", stderr);
		}

		if (block->buf_fix_count) {
			fprintf(stderr, "buffix count %lu ",
				(ulong) block->buf_fix_count);
		}

		if (block->io_fix) {
			fprintf(stderr, "io_fix %lu ", (ulong) block->io_fix);
		}

		if (ut_dulint_cmp(block->oldest_modification,
				ut_dulint_zero) > 0) {
			fputs("modif. ", stderr);
		}

		frame = buf_block_get_frame(block);

		fprintf(stderr, "LRU pos %lu type %lu index id %lu ",
			(ulong) block->LRU_position,
			(ulong) fil_page_get_type(frame),
			(ulong) ut_dulint_get_low(btr_page_get_index_id(frame)));

		block = UT_LIST_GET_NEXT(LRU, block);
		if (++len == 10) {
			len = 0;
			putc('\n', stderr);
		}
	}

	mutex_exit(&(buf_pool->mutex));
}
#endif /* UNIV_DEBUG */