Method SendCycle

library/cpp/netliba/v12/udp_host.cpp:777–829

    }

    bool TUdpHost::SendCycle(ui8 prio) {
        bool res1 = Connections.ForEachSendingConnection([prio, this](TSendingConnectionsList::iterator& sc) {
            typedef TConnections::ESentConnectionResult TSentConnectionResult;
            TConnection* connection = sc->Get();
            TDeque<ui64>& transferIdQueue = connection->GetSendingTransfers(prio);
            for (TDeque<ui64>::iterator z = transferIdQueue.begin(); z != transferIdQueue.end();) {
                const ui64 transferId = *z;
                TUdpOutTransfer* xfer = connection->GetSendQueue().Get(transferId);
                if (!xfer) {
                    z = transferIdQueue.erase(z);
                    if (transferIdQueue.empty()) {
                        return connection->HasAnySendingTransfers() ? TSentConnectionResult::SCR_CONT : TSentConnectionResult::SCR_DELETE; //delete connection if all queues are empty
                    } else {
                        continue;
                    }
                } else {
                    Y_ASSERT(connection->IsAlive());
                }
                const float deltaT = (float)NHPTimer::GetSeconds(CurrentT - xfer->LastTime);
                xfer->LastTime = CurrentT;

                if (!xfer->AckTracker.IsInitialized()) {
                    // Cerr << GetAddressAsString(connection->GetAddress()) << " Checking MTU for conn=" << ui64(connection) << ", xfer=" << ui64(xfer) << Endl;
                    if (!CheckMTU(connection, *xfer)) {
                        return TSentConnectionResult::SCR_CONT; //if we can`t get MTU for transfer we can`t get for connection
                    }
                    xfer->InitXfer();
                }
                xfer->AckTracker.Step(deltaT);
                MaxWaitTime = Min(MaxWaitTime, xfer->AckTracker.GetTimeToNextPacketTimeout());

                for (;;) {
                    if (!xfer->AckTracker.CanSend()) {
                        if (xfer->TriedToSendAtLeastOnePacket) {
                            //we can`t stop iteration if we start sending
                            break;
                        }
                        return TSentConnectionResult::SCR_CONT; //we can`t send more for current connection
                    }
                    TUdpHost::ESentPacketResult res2 = SendTransferPacket(connection, xfer, transferId);
                    if (res2 == TUdpHost::ESentPacketResult::SPR_STOP_SENDING_TRANSFER) {
                        break;
                    } else if (res2 == TUdpHost::ESentPacketResult::SPR_OVERFLOW) {
                        return TSentConnectionResult::SCR_BREAK;
                    }
                }
                ++z;
            }
            return TSentConnectionResult::SCR_CONT;
        });
        FlushPackets();
        return res1;
    }

    //Calls FlushPackets and checks status of current xfer
    //if got FPR_OUT_TRANSFERS_CHANGED for current xfer - current xfer is invalid. Return errors