public void transceive(List<ByteBuffer> request,
Callback<List<ByteBuffer>> callback) throws IOException {
stateLock.readLock().lock();
try {
int serial = serialGenerator.incrementAndGet();
NettyDataPack dataPack = new NettyDataPack(serial, request);
requests.put(serial, callback);
writeDataPack(dataPack);
} finally {
stateLock.readLock().unlock();
}