buf0buf.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

	block->modify_clock = ut_dulint_zero;
	
	block->file_page_was_freed = FALSE;

	block->check_index_page_at_flush = FALSE;
	block->index = NULL;

	block->in_free_list = FALSE;
	block->in_LRU_list = FALSE;

	block->n_pointers = 0;

	rw_lock_create(&(block->lock));
	ut_ad(rw_lock_validate(&(block->lock)));

#ifdef UNIV_SYNC_DEBUG
	rw_lock_create(&(block->debug_latch));
	rw_lock_set_level(&(block->debug_latch), SYNC_NO_ORDER_CHECK);
#endif /* UNIV_SYNC_DEBUG */
}

/************************************************************************
Creates the buffer pool. */

buf_pool_t*
buf_pool_init(
/*==========*/
				/* out, own: buf_pool object, NULL if not
				enough memory or error */
	ulint	max_size,	/* in: maximum size of the buf_pool in
				blocks */
	ulint	curr_size,	/* in: current size to use, must be <=
				max_size, currently must be equal to
				max_size */
	ulint	n_frames)	/* in: number of frames; if AWE is used,
				this is the size of the address space window
				where physical memory pages are mapped; if
				AWE is not used then this must be the same
				as max_size */
{
	byte*		frame;
	ulint		i;
	buf_block_t*	block;
	
	ut_a(max_size == curr_size);
	ut_a(srv_use_awe || n_frames == max_size);
	
	if (n_frames > curr_size) {
	        fprintf(stderr,
"InnoDB: AWE: Error: you must specify in my.cnf .._awe_mem_mb larger\n"
"InnoDB: than .._buffer_pool_size. Now the former is %lu pages,\n"
"InnoDB: the latter %lu pages.\n", (ulong) curr_size, (ulong) n_frames);

		return(NULL);
	}

	buf_pool = mem_alloc(sizeof(buf_pool_t));

	/* 1. Initialize general fields
	   ---------------------------- */
	mutex_create(&(buf_pool->mutex));
	mutex_set_level(&(buf_pool->mutex), SYNC_BUF_POOL);

	mutex_enter(&(buf_pool->mutex));

	if (srv_use_awe) {
		/*----------------------------------------*/
		/* Allocate the virtual address space window, i.e., the
		buffer pool frames */

		buf_pool->frame_mem = os_awe_allocate_virtual_mem_window(
					UNIV_PAGE_SIZE * (n_frames + 1));
					
		/* Allocate the physical memory for AWE and the AWE info array
		for buf_pool */

		if ((curr_size % ((1024 * 1024) / UNIV_PAGE_SIZE)) != 0) {

		        fprintf(stderr,
"InnoDB: AWE: Error: physical memory must be allocated in full megabytes.\n"
"InnoDB: Trying to allocate %lu database pages.\n", 
			  (ulong) curr_size);

		        return(NULL);
		}

		if (!os_awe_allocate_physical_mem(&(buf_pool->awe_info),
			curr_size / ((1024 * 1024) / UNIV_PAGE_SIZE))) {

			return(NULL);
		}
		/*----------------------------------------*/
	} else {
		buf_pool->frame_mem = os_mem_alloc_large(
					UNIV_PAGE_SIZE * (n_frames + 1),
					TRUE, FALSE);
	}

	if (buf_pool->frame_mem == NULL) {

		return(NULL);
	}

	buf_pool->blocks = ut_malloc(sizeof(buf_block_t) * max_size);

	if (buf_pool->blocks == NULL) {

		return(NULL);
	}

	buf_pool->max_size = max_size;
	buf_pool->curr_size = curr_size;

	buf_pool->n_frames = n_frames;

	/* Align pointer to the first frame */

	frame = ut_align(buf_pool->frame_mem, UNIV_PAGE_SIZE);

	buf_pool->frame_zero = frame;
	buf_pool->high_end = frame + UNIV_PAGE_SIZE * n_frames;

	if (srv_use_awe) {
		/*----------------------------------------*/
		/* Map an initial part of the allocated physical memory to
		the window */

		os_awe_map_physical_mem_to_window(buf_pool->frame_zero,
				n_frames *
				(UNIV_PAGE_SIZE / OS_AWE_X86_PAGE_SIZE),
					buf_pool->awe_info);
		/*----------------------------------------*/
	}

	buf_pool->blocks_of_frames = ut_malloc(sizeof(void*) * n_frames);
	
	if (buf_pool->blocks_of_frames == NULL) {

		return(NULL);
	}

	/* Init block structs and assign frames for them; in the case of
	AWE there are less frames than blocks. Then we assign the frames
	to the first blocks (we already mapped the memory above). We also
	init the awe_info for every block. */

	for (i = 0; i < max_size; i++) {

		block = buf_pool_get_nth_block(buf_pool, i);

		if (i < n_frames) {
			frame = buf_pool->frame_zero + i * UNIV_PAGE_SIZE;
			*(buf_pool->blocks_of_frames + i) = block;
		} else {
			frame = NULL;
		}
		
		buf_block_init(block, frame);

		if (srv_use_awe) {
			/*----------------------------------------*/
			block->awe_info = buf_pool->awe_info
				+ i * (UNIV_PAGE_SIZE / OS_AWE_X86_PAGE_SIZE);
			/*----------------------------------------*/
		}
	}

	buf_pool->page_hash = hash_create(2 * max_size);

	buf_pool->n_pend_reads = 0;

	buf_pool->last_printout_time = time(NULL);

	buf_pool->n_pages_read = 0;
	buf_pool->n_pages_written = 0;
	buf_pool->n_pages_created = 0;
	buf_pool->n_pages_awe_remapped = 0;
	
	buf_pool->n_page_gets = 0;
	buf_pool->n_page_gets_old = 0;
	buf_pool->n_pages_read_old = 0;
	buf_pool->n_pages_written_old = 0;
	buf_pool->n_pages_created_old = 0;
	buf_pool->n_pages_awe_remapped_old = 0;
	
	/* 2. Initialize flushing fields
	   ---------------------------- */
	UT_LIST_INIT(buf_pool->flush_list);

	for (i = BUF_FLUSH_LRU; i <= BUF_FLUSH_LIST; i++) {
		buf_pool->n_flush[i] = 0;
		buf_pool->init_flush[i] = FALSE;
		buf_pool->no_flush[i] = os_event_create(NULL);
	}

	buf_pool->LRU_flush_ended = 0;

	buf_pool->ulint_clock = 1;
	buf_pool->freed_page_clock = 0;
	
	/* 3. Initialize LRU fields
	   ---------------------------- */
	UT_LIST_INIT(buf_pool->LRU);

	buf_pool->LRU_old = NULL;

	UT_LIST_INIT(buf_pool->awe_LRU_free_mapped);

	/* Add control blocks to the free list */
	UT_LIST_INIT(buf_pool->free);

	for (i = 0; i < curr_size; i++) {

		block = buf_pool_get_nth_block(buf_pool, i);

		if (block->frame) {
			/* Wipe contents of frame to eliminate a Purify
			warning */

#ifdef HAVE_purify
			memset(block->frame, '\0', UNIV_PAGE_SIZE);
#endif
			if (srv_use_awe) {
				/* Add to the list of blocks mapped to
				frames */
				
				UT_LIST_ADD_LAST(awe_LRU_free_mapped,
					buf_pool->awe_LRU_free_mapped, block);
			}
		}

		UT_LIST_ADD_LAST(free, buf_pool->free, block);
		block->in_free_list = TRUE;
	}

	mutex_exit(&(buf_pool->mutex));

	if (srv_use_adaptive_hash_indexes) {
	  	btr_search_sys_create(
			  curr_size * UNIV_PAGE_SIZE / sizeof(void*) / 64);
	} else {
	        /* Create only a small dummy system */
	        btr_search_sys_create(1000);
	}

	return(buf_pool);
}	

/************************************************************************
Maps the page of block to a frame, if not mapped yet. Unmaps some page
from the end of the awe_LRU_free_mapped. */

void
buf_awe_map_page_to_frame(
/*======================*/
	buf_block_t*	block,		/* in: block whose page should be
					mapped to a frame */
	ibool		add_to_mapped_list) /* in: TRUE if we in the case
					we need to map the page should also
					add the block to the
					awe_LRU_free_mapped list */
{
	buf_block_t*	bck;

#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(buf_pool->mutex)));
#endif /* UNIV_SYNC_DEBUG */
	ut_ad(block);

	if (block->frame) {

		return;
	}

	/* Scan awe_LRU_free_mapped from the end and try to find a block
	which is not bufferfixed or io-fixed */

	bck = UT_LIST_GET_LAST(buf_pool->awe_LRU_free_mapped);

	while (bck) {	
		if (bck->state == BUF_BLOCK_FILE_PAGE
	    	    && (bck->buf_fix_count != 0 || bck->io_fix != 0)) {

			/* We have to skip this */
			bck = UT_LIST_GET_PREV(awe_LRU_free_mapped, bck);
		} else {
			/* We can map block to the frame of bck */

			os_awe_map_physical_mem_to_window(
				bck->frame,
				UNIV_PAGE_SIZE / OS_AWE_X86_PAGE_SIZE,
				block->awe_info);

			block->frame = bck->frame;

			*(buf_pool->blocks_of_frames
				+ (((ulint)(block->frame
						- buf_pool->frame_zero))
						>> UNIV_PAGE_SIZE_SHIFT))
				= block;
			
			bck->frame = NULL;
			UT_LIST_REMOVE(awe_LRU_free_mapped,
					buf_pool->awe_LRU_free_mapped,
					bck);

			if (add_to_mapped_list) {
				UT_LIST_ADD_FIRST(awe_LRU_free_mapped,
					buf_pool->awe_LRU_free_mapped,
					block);
			}

			buf_pool->n_pages_awe_remapped++;
			
			return;
		}
	}

	fprintf(stderr,
"InnoDB: AWE: Fatal error: cannot find a page to unmap\n"
"InnoDB: awe_LRU_free_mapped list length %lu\n",
		(ulong) UT_LIST_GET_LEN(buf_pool->awe_LRU_free_mapped));

	ut_a(0);
}

/************************************************************************
Allocates a buffer block. */
UNIV_INLINE
buf_block_t*
buf_block_alloc(void)
/*=================*/
				/* out, own: the allocated block; also if AWE
				is used it is guaranteed that the page is
				mapped to a frame */
{
	buf_block_t*	block;

	block = buf_LRU_get_free_block();

	return(block);
}

/************************************************************************
Moves to the block to the start of the LRU list if there is a danger
that the block would drift out of the buffer pool. */
UNIV_INLINE
void
buf_block_make_young(
/*=================*/
	buf_block_t*	block)	/* in: block to make younger */
{
	if (buf_pool->freed_page_clock >= block->freed_page_clock 
				+ 1 + (buf_pool->curr_size / 1024)) {

		/* There has been freeing activity in the LRU list:
		best to move to the head of the LRU list */

		buf_LRU_make_block_young(block);
	}
}

/************************************************************************
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 from slipping out of
the buffer pool. */

void
buf_page_make_young(
/*=================*/
	buf_frame_t*	frame)	/* in: buffer frame of a file page */
{
	buf_block_t*	block;
	
	mutex_enter(&(buf_pool->mutex));

	block = buf_block_align(frame);

	ut_a(block->state == BUF_BLOCK_FILE_PAGE);

	buf_LRU_make_block_young(block);

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

/************************************************************************
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 */
{
	ut_a(block->state != BUF_BLOCK_FILE_PAGE);

	mutex_enter(&(buf_pool->mutex));

	buf_LRU_block_free_non_file_page(block);

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

/*************************************************************************
Allocates a buffer frame. */

buf_frame_t*
buf_frame_alloc(void)
/*=================*/
				/* out: buffer frame */
{
	return(buf_block_alloc()->frame);
}

/*************************************************************************
Frees a buffer frame which does not contain a file page. */

void
buf_frame_free(
/*===========*/
	buf_frame_t*	frame)	/* in: buffer frame */
{
	buf_block_free(buf_block_align(frame));
}
	
/************************************************************************
Returns the buffer control block if the page can be found in the buffer
pool. NOTE that it is possible that the page is not yet read
from disk, though. This is a very low-level function: use with care! */

buf_block_t*
buf_page_peek_block(
/*================*/
			/* out: control block if found from page hash table,
			otherwise NULL; NOTE that the page is not necessarily
			yet read from disk! */
	ulint	space,	/* in: space id */
	ulint	offset)	/* in: page number */
{
	buf_block_t*	block;

	mutex_enter_fast(&(buf_pool->mutex));

	block = buf_page_hash_get(space, offset);

	mutex_exit(&(buf_pool->mutex));

	return(block);
}

/************************************************************************
Resets the check_index_page_at_flush field of a page if found in the buffer
pool. */

void
buf_reset_check_index_page_at_flush(
/*================================*/
	ulint	space,	/* in: space id */
	ulint	offset)	/* in: page number */
{
	buf_block_t*	block;

	mutex_enter_fast(&(buf_pool->mutex));

	block = buf_page_hash_get(space, offset);

	if (block) {
		block->check_index_page_at_flush = FALSE;
	}
	
	mutex_exit(&(buf_pool->mutex));
}

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