Method loadInventoryPages

src/jrd/tpc.cpp:293–358

}

void TipCache::loadInventoryPages(thread_db* tdbb, GlobalTpcHeader* header)
{
	// check the header page for the oldest and newest transaction numbers

#ifdef SUPERSERVER_V2
	Database* dbb = tdbb->getDatabase();
	const TraNumber top = dbb->dbb_next_transaction;
	const TraNumber hdr_oldest = dbb->dbb_oldest_transaction;
#else
	WIN window(HEADER_PAGE_NUMBER);
	const Ods::header_page* header_page = (Ods::header_page*) CCH_FETCH(tdbb, &window, LCK_read, pag_header);
	const TraNumber hdr_oldest_transaction = Ods::getOIT(header_page);
	const TraNumber hdr_next_transaction = Ods::getNT(header_page);
	const AttNumber hdr_attachment_id = Ods::getAttID(header_page);
	CCH_RELEASE(tdbb, &window);
#endif

	header->oldest_transaction.store(hdr_oldest_transaction, std::memory_order_relaxed);
	header->latest_attachment_id.store(hdr_attachment_id, std::memory_order_relaxed);
	header->latest_transaction_id.store(hdr_next_transaction, std::memory_order_relaxed);

	// Check if TIP has any interesting transactions.
	// At database creation time, it doesn't and the code below breaks
	// if there isn't a single one transaction to care about.
	if (hdr_oldest_transaction >= hdr_next_transaction)
		return;

	// Round down the oldest to a multiple of four, which puts the
	// transaction in temporary buffer on a byte boundary
	TraNumber base = hdr_oldest_transaction & ~TRA_MASK;

	const FB_SIZE_T buffer_length = (hdr_next_transaction + 1 - base + TRA_MASK) / 4;
	Array<UCHAR> transactions(buffer_length);

	UCHAR* buffer = transactions.begin();
	TRA_get_inventory(tdbb, buffer, base, hdr_next_transaction);

	static const CommitNumber init_state_mapping[4] = {CN_ACTIVE, CN_LIMBO, CN_DEAD, CN_PREHISTORIC};

	TpcBlockNumber blockNumber = hdr_oldest_transaction / m_transactionsPerBlock;
	ULONG transOffset = hdr_oldest_transaction % m_transactionsPerBlock;

	SyncLockGuard sync(&m_sync_status, SYNC_EXCLUSIVE, FB_FUNCTION);
	TransactionStatusBlock* statusBlock = createTransactionStatusBlock(header->tpc_block_size, blockNumber);

	for (TraNumber t = hdr_oldest_transaction; ; )
	{
		int state = TRA_state(buffer, base, t);
		CommitNumber cn = init_state_mapping[state];

		// Barrier is not needed as our thread is the only one here.
		// At the same time, simple write to a volatile variable is not good
		// as it is not deterministic. Some compilers generate barriers and some do not.
		(statusBlock->data + transOffset)->store(cn, std::memory_order_relaxed);

		if (++t > hdr_next_transaction)
			break;