Method StatusBlockData

src/jrd/tpc.cpp:372–412

}

TipCache::StatusBlockData::StatusBlockData(thread_db* tdbb, TipCache* tipCache, ULONG blockSize, TpcBlockNumber blkNumber)
	: blockNumber(blkNumber),
	  memory(NULL),
	  existenceLock(tdbb, sizeof(TpcBlockNumber), LCK_tpc_block, this, tpc_block_blocking_ast),
	  cache(tipCache),
	  acceptAst(false)
{
	Database* dbb = tdbb->getDatabase();

	existenceLock.setKey(blockNumber);

	if (!LCK_lock(tdbb, &existenceLock, LCK_PR, LCK_WAIT))
		ERR_bugcheck_msg("Unable to obtain memory block lock");

	PathName fileName = makeSharedMemoryFileName(dbb, blockNumber, false);

	try
	{
		// Here SharedMemory constructor is called with skipLock parameter set to true.
		// Appropriate locking is performed by existenceLock using LM.
		// This should be in sync with SharedMemoryBase::unlinkFile() call
		// in TipCache::StatusBlockData::clear().
		memory = FB_NEW_POOL(*dbb->dbb_permanent) SharedMemory<TransactionStatusBlock>(
			fileName.c_str(), blockSize,
			&cache->memBlockInitializer, true);

		const auto* header = memory->getHeader();
		cache->memBlockInitializer.checkHeader(header);

		LCK_convert(tdbb, &existenceLock, LCK_SR, LCK_WAIT);	// never fails
		acceptAst = true;
	}
	catch (const Exception& ex)
	{
		iscLogException("TPC: Cannot initialize the shared memory region (transactions status block)", ex);
		LCK_release(tdbb, &existenceLock);
		throw;
	}

	fb_assert(memory->getHeader()->mhb_version == TPC_VERSION);
}

PathName TipCache::StatusBlockData::makeSharedMemoryFileName(Database* dbb, TpcBlockNumber n, bool fullPath)
{