Random java.lang.IllegalArgumentException when using kryonet

Ed_RockStarGuy · January 3, 2015, 1:47pm

I have been playing around with cryonet and i have found that i keep getting a

[quote]Exception in thread “Thread-0” java.lang.IllegalArgumentException
at java.nio.Buffer.position(Buffer.java:236)
at com.esotericsoftware.kryonet.TcpConnection.send(TcpConnection.java:206)
at com.esotericsoftware.kryonet.Connection.sendTCP(Connection.java:77)
at com.horizon.game.map.MapData.pullChunkFromServer(MapData.java:1202)
[/quote]
randomly, everything seems to work fine but randomly on occasions i get this, anyone know a fix since it seems to be a fault with kryonet itself?

CopyableCougar4 · January 3, 2015, 4:23pm

Just looking at kryonet’s source, it seems that that error occurs when you overfill the [icode]writeBuffer[/icode] object.

github.com

EsotericSoftware/kryonet/blob/master/src/com/esotericsoftware/kryonet/TcpConnection.java#L199


			}
			if (socketChannel.write(buffer) == 0) break;
		}
		buffer.compact();

		return buffer.position() == 0;
	}

	/** This method is thread safe. */
	public int send (Connection connection, Object object) throws IOException {
		SocketChannel socketChannel = this.socketChannel;
		if (socketChannel == null) throw new SocketException("Connection is closed.");
		synchronized (writeLock) {
			int start = writeBuffer.position();
			int lengthLength = serialization.getLengthLength();
			try {
				// Leave room for length.
				writeBuffer.position(writeBuffer.position() + lengthLength);

				// Write data.
				serialization.write(connection, writeBuffer, object);

In the constructor for a TcpConnection, it seems you set the writebuffer size. Maybe try increasing that slightly?

github.com

EsotericSoftware/kryonet/blob/master/src/com/esotericsoftware/kryonet/TcpConnection.java#L50


	boolean bufferPositionFix;
	int timeoutMillis = 12000;
	float idleThreshold = 0.1f;

	final Serialization serialization;
	private SelectionKey selectionKey;
	private volatile long lastWriteTime, lastReadTime;
	private int currentObjectLength;
	private final Object writeLock = new Object();

	public TcpConnection (Serialization serialization, int writeBufferSize, int objectBufferSize) {
		this.serialization = serialization;
		writeBuffer = ByteBuffer.allocate(writeBufferSize);
		readBuffer = ByteBuffer.allocate(objectBufferSize);
		readBuffer.flip();
	}

	public SelectionKey accept (Selector selector, SocketChannel socketChannel) throws IOException {
		writeBuffer.clear();
		readBuffer.clear();
		readBuffer.flip();