Function CCH_clean_page

src/jrd/cch.cpp:288–363

void CCH_clean_page(thread_db* tdbb, PageNumber page)
{
/**************************************
 *  C C H _ c l e a n _ p a g e
 **************************************
 *
 * Functional description
 *  Clear dirty status and dependencies. Buffer must be unused.
 *  If buffer with given page number is not found - it is OK, do nothing.
 *  Used to remove dirty pages from cache after releasing temporary objects.
 *
 **************************************/
	SET_TDBB(tdbb);
	Database* dbb = tdbb->getDatabase();

	fb_assert(page.getPageNum() > 0);
	fb_assert(page.isTemporary());
	if (!page.isTemporary())
		return;

	BufferControl* bcb = dbb->dbb_bcb;
	BufferDesc* bdb = NULL;
	{
#ifndef HASH_USE_CDS_LIST
		Sync bcbSync(&bcb->bcb_syncObject, "CCH_clean_page");
		bcbSync.lock(SYNC_SHARED);
#endif

		bdb = bcb->bcb_hashTable->find(page);
		if (!bdb)
			return;

		fb_assert(bdb->bdb_use_count == 0);
		if (!bdb->addRefConditional(tdbb, SYNC_EXCLUSIVE))
			return;
	}

	// temporary pages should have no precedence relationship
	if (!QUE_EMPTY(bdb->bdb_higher))
		purgePrecedence(bcb, bdb);

	fb_assert(QUE_EMPTY(bdb->bdb_higher));
	fb_assert(QUE_EMPTY(bdb->bdb_lower));

	if (!QUE_EMPTY(bdb->bdb_lower) || !QUE_EMPTY(bdb->bdb_higher))
	{
		bdb->release(tdbb, true);
		return;
	}

	if (bdb->bdb_flags & (BDB_dirty | BDB_db_dirty))
	{
		bdb->bdb_difference_page = 0;
		bdb->bdb_transactions = 0;
		bdb->bdb_mark_transaction = 0;

		if (!(bdb->bdb_bcb->bcb_flags & BCB_keep_pages))
			removeDirty(dbb->dbb_bcb, bdb);