Method cacheState

src/jrd/tpc.cpp:198–226

}

CommitNumber TipCache::cacheState(TraNumber number)
{
	fb_assert(m_tpcHeader);
	GlobalTpcHeader* header = m_tpcHeader->getHeader();

	TraNumber oldest = header->oldest_transaction.load(std::memory_order_relaxed);

	if (number < oldest)
		return CN_PREHISTORIC;

	TpcBlockNumber blockNumber = number / m_transactionsPerBlock;
	ULONG offset = number % m_transactionsPerBlock;

	Sync sync(&m_sync_status, FB_FUNCTION);
	TransactionStatusBlock* block = getTransactionStatusBlock(header, blockNumber, sync);

	// This should not really happen ever
	fb_assert(block);

	if (!block)
		return CN_PREHISTORIC;

	// Barrier is not needed here when we are reading state from cache
	// because all callers of this function are prepared to handle
	// slightly out-dated information and will take slow path if necessary
	CommitNumber state = block->data[offset];

	return state;
}

void TipCache::initializeTpc(thread_db *tdbb)
{