buf0buf.ic

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

/******************************************************
The database buffer buf_pool

(c) 1995 Innobase Oy

Created 11/5/1995 Heikki Tuuri
*******************************************************/

#include "buf0flu.h"
#include "buf0lru.h"
#include "buf0rea.h"
#include "mtr0mtr.h"

#ifdef UNIV_DEBUG
extern ulint		buf_dbg_counter; /* This is used to insert validation
					operations in execution in the
					debug version */
#endif /* UNIV_DEBUG */
/************************************************************************
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. */
UNIV_INLINE
ibool
buf_block_peek_if_too_old(
/*======================*/
				/* out: TRUE if should be made younger */
	buf_block_t*	block)	/* in: block to make younger */
{
	return(buf_pool->freed_page_clock >= block->freed_page_clock
				+ 1 + (buf_pool->curr_size / 1024));
}

/*************************************************************************
Gets the current size of buffer buf_pool in bytes. In the case of AWE, the
size of AWE window (= the frames). */
UNIV_INLINE
ulint
buf_pool_get_curr_size(void)
/*========================*/
			/* out: size in bytes */
{
	return((buf_pool->n_frames) * UNIV_PAGE_SIZE);
}	

/*************************************************************************
Gets the maximum size of buffer buf_pool in bytes. In the case of AWE, the
size of AWE window (= the frames). */
UNIV_INLINE
ulint
buf_pool_get_max_size(void)
/*=======================*/
			/* out: size in bytes */
{
	return((buf_pool->n_frames) * UNIV_PAGE_SIZE);
}	

/***********************************************************************
Accessor function for block array. */
UNIV_INLINE
buf_block_t*
buf_pool_get_nth_block(
/*===================*/
				/* out: pointer to block */
	buf_pool_t*	buf_pool,/* in: buf_pool */
	ulint		i)	/* in: index of the block */
{
	ut_ad(buf_pool);
	ut_ad(i < buf_pool->max_size);

	return(i + buf_pool->blocks);
}	

/***********************************************************************
Checks if a pointer points to the block array of the buffer pool (blocks, not
the frames). */
UNIV_INLINE
ibool
buf_pool_is_block(
/*==============*/
			/* out: TRUE if pointer to block */
	void*	ptr)	/* in: pointer to memory */
{
	if ((buf_pool->blocks <= (buf_block_t*)ptr)
	    && ((buf_block_t*)ptr < buf_pool->blocks + buf_pool->max_size)) {

		return(TRUE);
	}

	return(FALSE);
}	

/************************************************************************
Gets the smallest oldest_modification lsn for any page in the pool. Returns
ut_dulint_zero if all modified pages have been flushed to disk. */
UNIV_INLINE
dulint
buf_pool_get_oldest_modification(void)
/*==================================*/
				/* out: oldest modification in pool,
				ut_dulint_zero if none */
{
	buf_block_t*	block;
	dulint		lsn;
	
	mutex_enter(&(buf_pool->mutex));

	block = UT_LIST_GET_LAST(buf_pool->flush_list);

	if (block == NULL) {
		lsn = ut_dulint_zero;
	} else {
		lsn = block->oldest_modification;
	}

	mutex_exit(&(buf_pool->mutex));

	return(lsn);
}

/***********************************************************************
Increments the buf_pool clock by one and returns its new value. Remember
that in the 32 bit version the clock wraps around at 4 billion! */
UNIV_INLINE
ulint
buf_pool_clock_tic(void)
/*====================*/
			/* out: new clock value */
{
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(buf_pool->mutex)));
#endif /* UNIV_SYNC_DEBUG */
	
	buf_pool->ulint_clock++;

	return(buf_pool->ulint_clock);
}

/*************************************************************************
Gets a pointer to the memory frame of a block. */
UNIV_INLINE
buf_frame_t*
buf_block_get_frame(
/*================*/
				/* out: pointer to the frame */
	buf_block_t*	block)	/* in: pointer to the control block */
{
	ut_ad(block);
	ut_ad(block >= buf_pool->blocks);
	ut_ad(block < buf_pool->blocks + buf_pool->max_size);
	ut_ad(block->state != BUF_BLOCK_NOT_USED); 
	ut_ad((block->state != BUF_BLOCK_FILE_PAGE) 
	      || (block->buf_fix_count > 0));
	
	return(block->frame);
}	

/*************************************************************************
Gets the space id of a block. */
UNIV_INLINE
ulint
buf_block_get_space(
/*================*/
				/* out: space id */
	buf_block_t*	block)	/* in: pointer to the control block */
{
	ut_ad(block);
	ut_ad(block >= buf_pool->blocks);
	ut_ad(block < buf_pool->blocks + buf_pool->max_size);
	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
	ut_ad(block->buf_fix_count > 0);
	
	return(block->space);
}	

/*************************************************************************
Gets the page number of a block. */
UNIV_INLINE
ulint
buf_block_get_page_no(
/*==================*/
				/* out: page number */
	buf_block_t*	block)	/* in: pointer to the control block */
{
	ut_ad(block);
	ut_ad(block >= buf_pool->blocks);
	ut_ad(block < buf_pool->blocks + buf_pool->max_size);
	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
	ut_ad(block->buf_fix_count > 0);
	
	return(block->offset);
}	

/***********************************************************************
Gets the block to whose frame the pointer is pointing to. */
UNIV_INLINE
buf_block_t*
buf_block_align(
/*============*/
			/* out: pointer to block */
	byte*	ptr)	/* in: pointer to a frame */
{
	buf_block_t*	block;
	buf_frame_t*	frame_zero;

	ut_ad(ptr);

	frame_zero = buf_pool->frame_zero;

	if (UNIV_UNLIKELY((ulint)ptr < (ulint)frame_zero)
	    || UNIV_UNLIKELY((ulint)ptr > (ulint)(buf_pool->high_end))) {

		ut_print_timestamp(stderr);	
		fprintf(stderr,
"InnoDB: Error: trying to access a stray pointer %p\n"
"InnoDB: buf pool start is at %p, end at %p\n"
"InnoDB: Probable reason is database corruption or memory\n"
"InnoDB: corruption. If this happens in an InnoDB database recovery,\n"
"InnoDB: you can look from section 6.1 at http://www.innodb.com/ibman.html\n"
"InnoDB: how to force recovery.\n",
 			ptr, frame_zero,
			buf_pool->high_end);
		ut_error;
	}
	
	block = *(buf_pool->blocks_of_frames + (((ulint)(ptr - frame_zero))
						>> UNIV_PAGE_SIZE_SHIFT));
	return(block);
}	

/***********************************************************************
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 */
{
	buf_frame_t*	frame;

	ut_ad(ptr);

	frame = ut_align_down(ptr, UNIV_PAGE_SIZE);

	if (UNIV_UNLIKELY((ulint)frame < (ulint)(buf_pool->frame_zero))
	    || UNIV_UNLIKELY((ulint)frame >= (ulint)(buf_pool->high_end))) {

		ut_print_timestamp(stderr);	
		fprintf(stderr,
"InnoDB: Error: trying to access a stray pointer %p\n"
"InnoDB: buf pool start is at %p, end at %p\n"
"InnoDB: Probable reason is database corruption or memory\n"
"InnoDB: corruption. If this happens in an InnoDB database recovery,\n"
"InnoDB: you can look from section 6.1 at http://www.innodb.com/ibman.html\n"
"InnoDB: how to force recovery.\n",
 			ptr, buf_pool->frame_zero,
			buf_pool->high_end);
		ut_error;
	}

	return(frame);
}

/**************************************************************************
Gets the page number of a pointer pointing within a buffer frame containing
a file page. */
UNIV_INLINE
ulint
buf_frame_get_page_no(
/*==================*/
			/* out: page number */
	byte*	ptr)	/* in: pointer to within a buffer frame */
{
	return(buf_block_get_page_no(buf_block_align(ptr)));
}

/**************************************************************************
Gets the space id of a pointer pointing within a buffer frame containing a
file page. */
UNIV_INLINE
ulint
buf_frame_get_space_id(
/*===================*/
			/* out: space id */
	byte*	ptr)	/* in: pointer to within a buffer frame */
{
	return(buf_block_get_space(buf_block_align(ptr)));
}

/**************************************************************************
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(
/*=================*/
	byte*		ptr,	/* in: pointer to a buffer frame */
	ulint*		space,	/* out: space id */
	fil_addr_t*	addr)	/* out: page offset and byte offset */
{
	buf_block_t*	block;

	block = buf_block_align(ptr);

	*space = buf_block_get_space(block);
	addr->page = buf_block_get_page_no(block);
	addr->boffset = ptr - buf_frame_align(ptr);
}

/**************************************************************************
Gets the hash value of the page the pointer is pointing to. This can be used
in searches in the lock hash table. */
UNIV_INLINE
ulint
buf_frame_get_lock_hash_val(
/*========================*/
			/* out: lock hash value */
	byte*	ptr)	/* in: pointer to within a buffer frame */
{
	buf_block_t*	block;

	block = buf_block_align(ptr);

	return(block->lock_hash_val);
}

/**************************************************************************
Gets the mutex number protecting the page record lock hash chain in the lock
table. */
UNIV_INLINE
mutex_t*