Exemplo n.º 1
0
/**********************************************************************//**
Allocate a block from a bigger object.
@return	allocated block */
static
void*
buf_buddy_alloc_from(
/*=================*/
	buf_pool_t*	buf_pool,	/*!< in: buffer pool instance */
	void*		buf,		/*!< in: a block that is free to use */
	ulint		i,		/*!< in: index of
					buf_pool->zip_free[] */
	ulint		j)		/*!< in: size of buf as an index
					of buf_pool->zip_free[] */
{
	ulint	offs	= BUF_BUDDY_LOW << j;
	ut_ad(j <= BUF_BUDDY_SIZES);
	ut_ad(i >= buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE));
	ut_ad(j >= i);
	ut_ad(!ut_align_offset(buf, offs));

	/* Add the unused parts of the block to the free lists. */
	while (j > i) {
		buf_page_t*	bpage;

		offs >>= 1;
		j--;

		bpage = (buf_page_t*) ((byte*) buf + offs);
		ut_d(memset(bpage, j, BUF_BUDDY_LOW << j));
		bpage->state = BUF_BLOCK_ZIP_FREE;
		ut_d(BUF_BUDDY_LIST_VALIDATE(buf_pool, i));
		buf_buddy_add_to_free(buf_pool, bpage, j);
	}

	return(buf);
}
Exemplo n.º 2
0
/**********************************************************************//**
Get the offset of the buddy of a compressed page frame.
@return	the buddy relative of page */
UNIV_INLINE
byte*
buf_buddy_get(
/*==========*/
	byte*	page,	/*!< in: compressed page */
	ulint	size)	/*!< in: page size in bytes */
{
	ut_ad(ut_is_2pow(size));
	ut_ad(size >= BUF_BUDDY_LOW);
	ut_ad(size < BUF_BUDDY_HIGH);
	ut_ad(!ut_align_offset(page, size));

	if (((ulint) page) & size) {
		return(page - size);
	} else {
		return(page + size);
	}
}
Exemplo n.º 3
0
/**********************************************************************//**
Deallocate a buffer frame of UNIV_PAGE_SIZE. */
static
void
buf_buddy_block_free(
/*=================*/
	buf_pool_t*	buf_pool,	/*!< in: buffer pool instance */
	void*		buf)		/*!< in: buffer frame to deallocate */
{
	const ulint	fold	= BUF_POOL_ZIP_FOLD_PTR(buf);
	buf_page_t*	bpage;
	buf_block_t*	block;

	ut_ad(buf_pool_mutex_own(buf_pool));
	ut_ad(!mutex_own(&buf_pool->zip_mutex));
	ut_a(!ut_align_offset(buf, UNIV_PAGE_SIZE));

	HASH_SEARCH(hash, buf_pool->zip_hash, fold, buf_page_t*, bpage,
		    ut_ad(buf_page_get_state(bpage) == BUF_BLOCK_MEMORY
			  && bpage->in_zip_hash && !bpage->in_page_hash),
		    ((buf_block_t*) bpage)->frame == buf);
	ut_a(bpage);
	ut_a(buf_page_get_state(bpage) == BUF_BLOCK_MEMORY);
	ut_ad(!bpage->in_page_hash);
	ut_ad(bpage->in_zip_hash);
	ut_d(bpage->in_zip_hash = FALSE);
	HASH_DELETE(buf_page_t, hash, buf_pool->zip_hash, fold, bpage);

	ut_d(memset(buf, 0, UNIV_PAGE_SIZE));
	UNIV_MEM_INVALID(buf, UNIV_PAGE_SIZE);

	block = (buf_block_t*) bpage;
	mutex_enter(&block->mutex);
	buf_LRU_block_free_non_file_page(block);
	mutex_exit(&block->mutex);

	ut_ad(buf_pool->buddy_n_frames > 0);
	ut_d(buf_pool->buddy_n_frames--);
}
Exemplo n.º 4
0
/**********************************************************************//**
Allocate a buffer block to the buddy allocator. */
static
void
buf_buddy_block_register(
/*=====================*/
	buf_block_t*	block)	/*!< in: buffer frame to allocate */
{
	buf_pool_t*	buf_pool = buf_pool_from_block(block);
	const ulint	fold = BUF_POOL_ZIP_FOLD(block);
	ut_ad(buf_pool_mutex_own(buf_pool));
	ut_ad(!mutex_own(&buf_pool->zip_mutex));
	ut_ad(buf_block_get_state(block) == BUF_BLOCK_READY_FOR_USE);

	buf_block_set_state(block, BUF_BLOCK_MEMORY);

	ut_a(block->frame);
	ut_a(!ut_align_offset(block->frame, UNIV_PAGE_SIZE));

	ut_ad(!block->page.in_page_hash);
	ut_ad(!block->page.in_zip_hash);
	ut_d(block->page.in_zip_hash = TRUE);
	HASH_INSERT(buf_page_t, hash, buf_pool->zip_hash, fold, &block->page);

	ut_d(buf_pool->buddy_n_frames++);
}
Exemplo n.º 5
0
/**********************************************************************//**
Try to relocate a block.
@return	TRUE if relocated */
static
ibool
buf_buddy_relocate(
/*===============*/
	buf_pool_t*	buf_pool,	/*!< in: buffer pool instance */
	void*		src,		/*!< in: block to relocate */
	void*		dst,		/*!< in: free block to relocate to */
	ulint		i)		/*!< in: index of
					buf_pool->zip_free[] */
{
	buf_page_t*	bpage;
	const ulint	size	= BUF_BUDDY_LOW << i;
	ullint		usec	= ut_time_us(NULL);
	mutex_t*	mutex;
	ulint		space;
	ulint		page_no;

	ut_ad(buf_pool_mutex_own(buf_pool));
	ut_ad(!mutex_own(&buf_pool->zip_mutex));
	ut_ad(!ut_align_offset(src, size));
	ut_ad(!ut_align_offset(dst, size));
	ut_ad(i >= buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE));
	UNIV_MEM_ASSERT_W(dst, size);

	/* We assume that all memory from buf_buddy_alloc()
	is used for compressed page frames. */

	/* We look inside the allocated objects returned by
	buf_buddy_alloc() and assume that each block is a compressed
	page that contains a valid space_id and page_no in the page
	header. Should the fields be invalid, we will be unable to
	relocate the block. */

	/* The src block may be split into smaller blocks,
	some of which may be free.  Thus, the
	mach_read_from_4() calls below may attempt to read
	from free memory.  The memory is "owned" by the buddy
	allocator (and it has been allocated from the buffer
	pool), so there is nothing wrong about this.  The
	mach_read_from_4() calls here will only trigger bogus
	Valgrind memcheck warnings in UNIV_DEBUG_VALGRIND builds. */
	space	= mach_read_from_4((const byte *) src
				   + FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID);
	page_no	= mach_read_from_4((const byte *) src
				   + FIL_PAGE_OFFSET);
	/* Suppress Valgrind warnings about conditional jump
	on uninitialized value. */
	UNIV_MEM_VALID(&space, sizeof space);
	UNIV_MEM_VALID(&page_no, sizeof page_no);
	bpage = buf_page_hash_get(buf_pool, space, page_no);

	if (!bpage || bpage->zip.data != src) {
		/* The block has probably been freshly
		allocated by buf_LRU_get_free_block() but not
		added to buf_pool->page_hash yet.  Obviously,
		it cannot be relocated. */

		return(FALSE);
	}

	if (page_zip_get_size(&bpage->zip) != size) {
		/* The block is of different size.  We would
		have to relocate all blocks covered by src.
		For the sake of simplicity, give up. */
		ut_ad(page_zip_get_size(&bpage->zip) < size);

		return(FALSE);
	}

	/* The block must have been allocated, but it may
	contain uninitialized data. */
	UNIV_MEM_ASSERT_W(src, size);

	mutex = buf_page_get_mutex(bpage);

	mutex_enter(mutex);

	if (buf_page_can_relocate(bpage)) {
		/* Relocate the compressed page. */
		ut_a(bpage->zip.data == src);
		memcpy(dst, src, size);
		bpage->zip.data = dst;
		mutex_exit(mutex);
		UNIV_MEM_INVALID(src, size);
		{
			buf_buddy_stat_t*	buddy_stat
				= &buf_pool->buddy_stat[i];
			buddy_stat->relocated++;
			buddy_stat->relocated_usec
				+= ut_time_us(NULL) - usec;
		}
		return(TRUE);
	}

	mutex_exit(mutex);
	return(FALSE);
}
Exemplo n.º 6
0
void
btr_pcur_store_position(
/*====================*/
	btr_pcur_t*	cursor, /* in: persistent cursor */
	mtr_t*		mtr)	/* in: mtr */
{
	page_cur_t*	page_cursor;
	rec_t*		rec;
	dict_tree_t*	tree;
	page_t*		page;
	ulint		offs;
	
	ut_a(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);

	tree = btr_cur_get_tree(btr_pcur_get_btr_cur(cursor));

	page_cursor = btr_pcur_get_page_cur(cursor);

	rec = page_cur_get_rec(page_cursor);
	page = ut_align_down(rec, UNIV_PAGE_SIZE);
	offs = ut_align_offset(rec, UNIV_PAGE_SIZE);

	ut_ad(mtr_memo_contains(mtr, buf_block_align(page),
							MTR_MEMO_PAGE_S_FIX)
	      || mtr_memo_contains(mtr, buf_block_align(page),
							MTR_MEMO_PAGE_X_FIX));
	ut_a(cursor->latch_mode != BTR_NO_LATCHES);

	if (UNIV_UNLIKELY(page_get_n_recs(page) == 0)) {
		/* It must be an empty index tree; NOTE that in this case
		we do not store the modify_clock, but always do a search
		if we restore the cursor position */

		ut_a(btr_page_get_next(page, mtr) == FIL_NULL);
		ut_a(btr_page_get_prev(page, mtr) == FIL_NULL);

		cursor->old_stored = BTR_PCUR_OLD_STORED;

		if (page_rec_is_supremum_low(offs)) {

			cursor->rel_pos = BTR_PCUR_AFTER_LAST_IN_TREE;
		} else {
			cursor->rel_pos = BTR_PCUR_BEFORE_FIRST_IN_TREE;
		}

		return;
	} 

	if (page_rec_is_supremum_low(offs)) {

		rec = page_rec_get_prev(rec);

		cursor->rel_pos = BTR_PCUR_AFTER;

	} else if (page_rec_is_infimum_low(offs)) {

		rec = page_rec_get_next(rec);

		cursor->rel_pos = BTR_PCUR_BEFORE;
	} else {
		cursor->rel_pos = BTR_PCUR_ON;
	}

	cursor->old_stored = BTR_PCUR_OLD_STORED;
	cursor->old_rec = dict_tree_copy_rec_order_prefix(tree, rec,
						&cursor->old_n_fields,
						&cursor->old_rec_buf,
						&cursor->buf_size);

	cursor->block_when_stored = buf_block_align(page);	
	cursor->modify_clock = buf_block_get_modify_clock(
				cursor->block_when_stored);
}