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

		/* NOTE that the call to ibuf may have moved the ownership of
		the x-latch to this OS thread: do not let this confuse you in
		debugging! */		
	
		ut_ad(buf_pool->n_pend_reads > 0);
		buf_pool->n_pend_reads--;
		buf_pool->n_pages_read++;

		rw_lock_x_unlock_gen(&(block->lock), BUF_IO_READ);

#ifdef UNIV_DEBUG
		if (buf_debug_prints) {
			fputs("Has read ", stderr);
		}
#endif /* UNIV_DEBUG */
	} else {
		ut_ad(io_type == BUF_IO_WRITE);

		/* Write means a flush operation: call the completion
		routine in the flush system */

		buf_flush_write_complete(block);

		rw_lock_s_unlock_gen(&(block->lock), BUF_IO_WRITE);

		buf_pool->n_pages_written++;

#ifdef UNIV_DEBUG
		if (buf_debug_prints) {
			fputs("Has written ", stderr);
		}
#endif /* UNIV_DEBUG */
	}
	
	mutex_exit(&(buf_pool->mutex));

#ifdef UNIV_DEBUG
	if (buf_debug_prints) {
		fprintf(stderr, "page space %lu page no %lu\n",
			(ulong) block->space, (ulong) block->offset);
	}
#endif /* UNIV_DEBUG */
}

/*************************************************************************
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. */

void
buf_pool_invalidate(void)
/*=====================*/
{
	ibool	freed;

	ut_ad(buf_all_freed());
	
	freed = TRUE;

	while (freed) {
		freed = buf_LRU_search_and_free_block(100);
	}
	
	mutex_enter(&(buf_pool->mutex));

	ut_ad(UT_LIST_GET_LEN(buf_pool->LRU) == 0);

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

#ifdef UNIV_DEBUG
/*************************************************************************
Validates the buffer buf_pool data structure. */

ibool
buf_validate(void)
/*==============*/
{
	buf_block_t*	block;
	ulint		i;
	ulint		n_single_flush	= 0;
	ulint		n_lru_flush	= 0;
	ulint		n_list_flush	= 0;
	ulint		n_lru		= 0;
	ulint		n_flush		= 0;
	ulint		n_free		= 0;
	ulint		n_page		= 0;
	
	ut_ad(buf_pool);

	mutex_enter(&(buf_pool->mutex));

	for (i = 0; i < buf_pool->curr_size; i++) {

		block = buf_pool_get_nth_block(buf_pool, i);

		if (block->state == BUF_BLOCK_FILE_PAGE) {

			ut_a(buf_page_hash_get(block->space,
						block->offset) == block);
			n_page++;

#ifdef UNIV_IBUF_DEBUG
			ut_a((block->io_fix == BUF_IO_READ)
			     || ibuf_count_get(block->space, block->offset)
								== 0);
#endif
			if (block->io_fix == BUF_IO_WRITE) {

				if (block->flush_type == BUF_FLUSH_LRU) {
					n_lru_flush++;
					ut_a(rw_lock_is_locked(&(block->lock),
							RW_LOCK_SHARED));
				} else if (block->flush_type ==
						BUF_FLUSH_LIST) {
					n_list_flush++;
				} else if (block->flush_type ==
						BUF_FLUSH_SINGLE_PAGE) {
					n_single_flush++;
				} else {
					ut_error;
				}

			} else if (block->io_fix == BUF_IO_READ) {

				ut_a(rw_lock_is_locked(&(block->lock),
							RW_LOCK_EX));
			}
			
			n_lru++;

			if (ut_dulint_cmp(block->oldest_modification,
						ut_dulint_zero) > 0) {
					n_flush++;
			}	
		
		} else if (block->state == BUF_BLOCK_NOT_USED) {
			n_free++;
		}
 	}

	if (n_lru + n_free > buf_pool->curr_size) {
		fprintf(stderr, "n LRU %lu, n free %lu\n", (ulong) n_lru, (ulong) n_free);
		ut_error;
	}

	ut_a(UT_LIST_GET_LEN(buf_pool->LRU) == n_lru);
	if (UT_LIST_GET_LEN(buf_pool->free) != n_free) {
		fprintf(stderr, "Free list len %lu, free blocks %lu\n",
			(ulong) UT_LIST_GET_LEN(buf_pool->free), (ulong) n_free);
		ut_error;
	}
	ut_a(UT_LIST_GET_LEN(buf_pool->flush_list) == n_flush);

	ut_a(buf_pool->n_flush[BUF_FLUSH_SINGLE_PAGE] == n_single_flush);
	ut_a(buf_pool->n_flush[BUF_FLUSH_LIST] == n_list_flush);
	ut_a(buf_pool->n_flush[BUF_FLUSH_LRU] == n_lru_flush);
	
	mutex_exit(&(buf_pool->mutex));

	ut_a(buf_LRU_validate());
	ut_a(buf_flush_validate());

	return(TRUE);
}	

/*************************************************************************
Prints info of the buffer buf_pool data structure. */

void
buf_print(void)
/*===========*/
{
	dulint*		index_ids;
	ulint*		counts;
	ulint		size;
	ulint		i;
	ulint		j;
	dulint		id;
	ulint		n_found;
	buf_frame_t* 	frame;
	dict_index_t*	index;
	
	ut_ad(buf_pool);

	size = buf_pool->curr_size;

	index_ids = mem_alloc(sizeof(dulint) * size);
	counts = mem_alloc(sizeof(ulint) * size);

	mutex_enter(&(buf_pool->mutex));
	
	fprintf(stderr,
		"buf_pool size %lu\n"
		"database pages %lu\n"
		"free pages %lu\n"
		"modified database pages %lu\n"
		"n pending reads %lu\n"
		"n pending flush LRU %lu list %lu single page %lu\n"
		"pages read %lu, created %lu, written %lu\n",
		(ulong) size,
		(ulong) UT_LIST_GET_LEN(buf_pool->LRU),
		(ulong) UT_LIST_GET_LEN(buf_pool->free),
		(ulong) UT_LIST_GET_LEN(buf_pool->flush_list),
		(ulong) buf_pool->n_pend_reads,
		(ulong) buf_pool->n_flush[BUF_FLUSH_LRU],
		(ulong) buf_pool->n_flush[BUF_FLUSH_LIST],
		(ulong) buf_pool->n_flush[BUF_FLUSH_SINGLE_PAGE],
		(ulong) buf_pool->n_pages_read, buf_pool->n_pages_created,
		(ulong) buf_pool->n_pages_written);

	/* Count the number of blocks belonging to each index in the buffer */
	
	n_found = 0;

	for (i = 0; i < size; i++) {
		frame = buf_pool_get_nth_block(buf_pool, i)->frame;

		if (fil_page_get_type(frame) == FIL_PAGE_INDEX) {

			id = btr_page_get_index_id(frame);

			/* Look for the id in the index_ids array */
			j = 0;

			while (j < n_found) {

				if (ut_dulint_cmp(index_ids[j], id) == 0) {
					(counts[j])++;

					break;
				}
				j++;
			}

			if (j == n_found) {
				n_found++;
				index_ids[j] = id;
				counts[j] = 1;
			}
		}
	}

	mutex_exit(&(buf_pool->mutex));

	for (i = 0; i < n_found; i++) {
		index = dict_index_get_if_in_cache(index_ids[i]);

		fprintf(stderr,
			"Block count for index %lu in buffer is about %lu",
		       (ulong) ut_dulint_get_low(index_ids[i]),
		       (ulong) counts[i]);

		if (index) {
			putc(' ', stderr);
			dict_index_name_print(stderr, NULL, index);
		}

		putc('\n', stderr);
	}
	
	mem_free(index_ids);
	mem_free(counts);

	ut_a(buf_validate());
}	
#endif /* UNIV_DEBUG */

/*************************************************************************
Returns the number of latched pages in the buffer pool. */

ulint
buf_get_latched_pages_number(void)
{
        buf_block_t* block;
        ulint i;
        ulint fixed_pages_number = 0;

        mutex_enter(&(buf_pool->mutex));

        for (i = 0; i < buf_pool->curr_size; i++) {

               block = buf_pool_get_nth_block(buf_pool, i);

               if (((block->buf_fix_count != 0) || (block->io_fix != 0)) &&
                    block->magic_n == BUF_BLOCK_MAGIC_N )
                       fixed_pages_number++;
        }

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

/*************************************************************************
Returns the number of pending buf pool ios. */

ulint
buf_get_n_pending_ios(void)
/*=======================*/
{
	return(buf_pool->n_pend_reads
		+ buf_pool->n_flush[BUF_FLUSH_LRU]
		+ buf_pool->n_flush[BUF_FLUSH_LIST]
		+ buf_pool->n_flush[BUF_FLUSH_SINGLE_PAGE]);
}

/*************************************************************************
Returns the ratio in percents of modified pages in the buffer pool /
database pages in the buffer pool. */

ulint
buf_get_modified_ratio_pct(void)
/*============================*/
{
	ulint	ratio;

	mutex_enter(&(buf_pool->mutex));

	ratio = (100 * UT_LIST_GET_LEN(buf_pool->flush_list))
		     / (1 + UT_LIST_GET_LEN(buf_pool->LRU)
		        + UT_LIST_GET_LEN(buf_pool->free));

		       /* 1 + is there to avoid division by zero */   

	mutex_exit(&(buf_pool->mutex));

	return(ratio);
}

/*************************************************************************
Prints info of the buffer i/o. */

void
buf_print_io(
/*=========*/
	FILE*	file)	/* in/out: buffer where to print */
{
	time_t	current_time;
	double	time_elapsed;
	ulint	size;
	
	ut_ad(buf_pool);
	size = buf_pool->curr_size;

	mutex_enter(&(buf_pool->mutex));
	
	if (srv_use_awe) {
		fprintf(stderr,
		"AWE: Buffer pool memory frames                        %lu\n",
				(ulong) buf_pool->n_frames);
		
		fprintf(stderr,
		"AWE: Database pages and free buffers mapped in frames %lu\n",
				(ulong) UT_LIST_GET_LEN(buf_pool->awe_LRU_free_mapped));
	}
	fprintf(file,
		"Buffer pool size   %lu\n"
		"Free buffers       %lu\n"
		"Database pages     %lu\n"
		"Modified db pages  %lu\n"
		"Pending reads %lu\n"
		"Pending writes: LRU %lu, flush list %lu, single page %lu\n",
		(ulong) size,
		(ulong) UT_LIST_GET_LEN(buf_pool->free),
		(ulong) UT_LIST_GET_LEN(buf_pool->LRU),
		(ulong) UT_LIST_GET_LEN(buf_pool->flush_list),
		(ulong) buf_pool->n_pend_reads,
		(ulong) buf_pool->n_flush[BUF_FLUSH_LRU]
			+ buf_pool->init_flush[BUF_FLUSH_LRU],
		(ulong) buf_pool->n_flush[BUF_FLUSH_LIST]
			+ buf_pool->init_flush[BUF_FLUSH_LIST],
		(ulong) buf_pool->n_flush[BUF_FLUSH_SINGLE_PAGE]);

	current_time = time(NULL);
	time_elapsed = 0.001 + difftime(current_time,
						buf_pool->last_printout_time);
	buf_pool->last_printout_time = current_time;

	fprintf(file,
		"Pages read %lu, created %lu, written %lu\n"
		"%.2f reads/s, %.2f creates/s, %.2f writes/s\n",
		(ulong) buf_pool->n_pages_read,
		(ulong) buf_pool->n_pages_created,
		(ulong) buf_pool->n_pages_written,
		(buf_pool->n_pages_read - buf_pool->n_pages_read_old)
		/ time_elapsed,
		(buf_pool->n_pages_created - buf_pool->n_pages_created_old)
		/ time_elapsed,
		(buf_pool->n_pages_written - buf_pool->n_pages_written_old)
		/ time_elapsed);

	if (srv_use_awe) {
		fprintf(file, "AWE: %.2f page remaps/s\n",
		(buf_pool->n_pages_awe_remapped
				- buf_pool->n_pages_awe_remapped_old)
			/ time_elapsed);
	}
		
	if (buf_pool->n_page_gets > buf_pool->n_page_gets_old) {
		fprintf(file, "Buffer pool hit rate %lu / 1000\n",
       (ulong) (1000
		- ((1000 *
		    (buf_pool->n_pages_read - buf_pool->n_pages_read_old))
		/ (buf_pool->n_page_gets - buf_pool->n_page_gets_old))));
	} else {
		fputs("No buffer pool page gets since the last printout\n",
			file);
	}

	buf_pool->n_page_gets_old = buf_pool->n_page_gets;
	buf_pool->n_pages_read_old = buf_pool->n_pages_read;
	buf_pool->n_pages_created_old = buf_pool->n_pages_created;
	buf_pool->n_pages_written_old = buf_pool->n_pages_written;
	buf_pool->n_pages_awe_remapped_old = buf_pool->n_pages_awe_remapped;

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

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

void
buf_refresh_io_stats(void)
/*======================*/
{
        buf_pool->last_printout_time = time(NULL);
	buf_pool->n_page_gets_old = buf_pool->n_page_gets;
	buf_pool->n_pages_read_old = buf_pool->n_pages_read;
	buf_pool->n_pages_created_old = buf_pool->n_pages_created;
	buf_pool->n_pages_written_old = buf_pool->n_pages_written;
	buf_pool->n_pages_awe_remapped_old = buf_pool->n_pages_awe_remapped; 
}

/*************************************************************************
Checks that all file pages in the buffer are in a replaceable state. */

ibool
buf_all_freed(void)
/*===============*/
{
	buf_block_t*	block;
	ulint		i;
	
	ut_ad(buf_pool);

	mutex_enter(&(buf_pool->mutex));

	for (i = 0; i < buf_pool->curr_size; i++) {

		block = buf_pool_get_nth_block(buf_pool, i);

		if (block->state == BUF_BLOCK_FILE_PAGE) {

			if (!buf_flush_ready_for_replace(block)) {

				fprintf(stderr,
					"Page %lu %lu still fixed or dirty\n",
					(ulong) block->space, (ulong) block->offset);
			    	ut_error;
			}
		}
 	}

	mutex_exit(&(buf_pool->mutex));

	return(TRUE);
}	

/*************************************************************************
Checks that there currently are no pending i/o-operations for the buffer
pool. */

ibool
buf_pool_check_no_pending_io(void)
/*==============================*/