C++ WT_BM::free方法代码示例

/*
 * __wt_rec_track_wrapup_err --
 *	Resolve the page's list of tracked objects after an error occurs.
 */
int
__wt_rec_track_wrapup_err(WT_SESSION_IMPL *session, WT_PAGE *page)
{
	WT_BM *bm;
	WT_DECL_RET;
	WT_PAGE_MODIFY *mod;
	WT_PAGE_TRACK *track;
	uint32_t i;

	bm = session->btree->bm;

	/*
	 * After a failed reconciliation of a page, discard entries added in the
	 * current reconciliation, their information is incorrect, additionally,
	 * clear the in-use flag in preparation for the next reconciliation.
	 */
	mod = page->modify;
	for (track = mod->track, i = 0; i < mod->track_entries; ++track, ++i)
		if (F_ISSET(track, WT_TRK_JUST_ADDED)) {
			/*
			 * The in-use flag is used to avoid discarding backing
			 * blocks: if an object is both just-added and in-use,
			 * we allocated the blocks on this run, and we want to
			 * discard them on error.
			 */
			if (F_ISSET(track, WT_TRK_INUSE))
				WT_TRET(bm->free(bm, session,
				    track->addr.addr, track->addr.size));

			__wt_free(session, track->addr.addr);
			memset(track, 0, sizeof(*track));
		} else
			F_CLR(track, WT_TRK_INUSE);
	return (ret);
}

/*
 * __ovfl_reuse_wrapup_err --
 *	Resolve the page's overflow reuse list after an error occurs.
 */
static int
__ovfl_reuse_wrapup_err(WT_SESSION_IMPL *session, WT_PAGE *page)
{
	WT_BM *bm;
	WT_DECL_RET;
	WT_OVFL_REUSE **e, **head, *reuse;
	size_t decr;
	int i;

	bm = S2BT(session)->bm;
	head = page->modify->ovfl_track->ovfl_reuse;

	/*
	 * Discard any overflow records that were just added, freeing underlying
	 * blocks.
	 *
	 * First, walk the overflow reuse lists (except for the lowest one),
	 * fixing up skiplist links.
	 */
	for (i = WT_SKIP_MAXDEPTH - 1; i > 0; --i)
		for (e = &head[i]; (reuse = *e) != NULL;) {
			if (!F_ISSET(reuse, WT_OVFL_REUSE_JUST_ADDED)) {
				e = &reuse->next[i];
				continue;
			}
			*e = reuse->next[i];
		}

	/*
	 * Second, discard any overflow record with a just-added flag, clear the
	 * flags for the next run.
	 */
	decr = 0;
	for (e = &head[0]; (reuse = *e) != NULL;) {
		if (!F_ISSET(reuse, WT_OVFL_REUSE_JUST_ADDED)) {
			F_CLR(reuse, WT_OVFL_REUSE_INUSE);
			e = &reuse->next[0];
			continue;
		}
		*e = reuse->next[0];

		if (WT_VERBOSE_ISSET(session, WT_VERB_OVERFLOW))
			WT_RET(
			    __ovfl_reuse_verbose(session, page, reuse, "free"));

		WT_TRET(bm->free(
		    bm, session, WT_OVFL_REUSE_ADDR(reuse), reuse->addr_size));
		decr += WT_OVFL_SIZE(reuse, WT_OVFL_REUSE);
		__wt_free(session, reuse);
	}

	if (decr != 0)
		__wt_cache_page_inmem_decr(session, page, decr);
	return (0);
}

/*
 * __wt_ovfl_discard --
 *	Discard an on-page overflow value, and reset the page's cell.
 */
int
__wt_ovfl_discard(WT_SESSION_IMPL *session, WT_CELL *cell)
{
	WT_BM *bm;
	WT_BTREE *btree;
	WT_CELL_UNPACK *unpack, _unpack;
	WT_DECL_RET;

	btree = S2BT(session);
	bm = btree->bm;
	unpack = &_unpack;

	__wt_cell_unpack(cell, unpack);

	/*
	 * Finally remove overflow key/value objects, called when reconciliation
	 * finishes after successfully writing a page.
	 *
	 * Keys must have already been instantiated and value objects must have
	 * already been cached (if they might potentially still be read by any
	 * running transaction).
	 *
	 * Acquire the overflow lock to avoid racing with a thread reading the
	 * backing overflow blocks.
	 */
	WT_RET(__wt_writelock(session, btree->ovfl_lock));

	switch (unpack->raw) {
	case WT_CELL_KEY_OVFL:
		__wt_cell_type_reset(session,
		    unpack->cell, WT_CELL_KEY_OVFL, WT_CELL_KEY_OVFL_RM);
		break;
	case WT_CELL_VALUE_OVFL:
		__wt_cell_type_reset(session,
		    unpack->cell, WT_CELL_VALUE_OVFL, WT_CELL_VALUE_OVFL_RM);
		break;
	WT_ILLEGAL_VALUE(session);
	}

	WT_TRET(__wt_writeunlock(session, btree->ovfl_lock));

	/* Free the backing disk blocks. */
	WT_TRET(bm->free(bm, session, unpack->data, unpack->size));

	return (ret);
}