Method executeReceiveWithRestarts

src/dsql/DsqlRequests.cpp:747–829

}

void DsqlDmlRequest::executeReceiveWithRestarts(thread_db* tdbb, jrd_tra** traHandle,
	IMessageMetadata* outMetadata, UCHAR* outMsg,
	bool singleton, bool exec, bool fetch)
{
	request->req_flags &= ~req_update_conflict;
	int numTries = 0;
	const int MAX_RESTARTS = 10;

	while (true)
	{
		AutoSavePoint savePoint(tdbb, req_transaction);

		// Don't set req_restart_ready flag at last attempt to restart request.
		// It allows to raise update conflict error (if any) as usual and
		// handle error by PSQL handler.
		const ULONG flag = (numTries >= MAX_RESTARTS) ? 0 : req_restart_ready;
		AutoSetRestoreFlag<ULONG> restartReady(&request->req_flags, flag, true);
		try
		{
			if (exec)
				doExecute(tdbb, traHandle, outMetadata, outMsg, singleton);

			if (fetch)
			{
				fb_assert(dsqlStatement->isCursorBased());

				const dsql_msg* message = dsqlStatement->getReceiveMsg();

				UCHAR* dsqlMsgBuffer = req_msg_buffers[message->msg_buffer_number];
				JRD_receive(tdbb, request, message->msg_number, message->msg_length, dsqlMsgBuffer);
			}
		}
		catch (const status_exception&)
		{
			if (!(req_transaction->tra_flags & TRA_ex_restart))
			{
				request->req_flags &= ~req_update_conflict;
				throw;
			}
		}

		if (!(request->req_flags & req_update_conflict))
		{
			fb_assert((req_transaction->tra_flags & TRA_ex_restart) == 0);
			req_transaction->tra_flags &= ~TRA_ex_restart;

#ifdef DEV_BUILD
			if (numTries > 0)
			{
				string s;
				s.printf("restarts = %d", numTries);

				ERRD_post_warning(Arg::Warning(isc_random) << Arg::Str(s));
			}
#endif
			savePoint.release();	// everything is ok
			break;
		}