[xSocket-develop] Question: SSL with non-threaded onData() hangs sometimes

[Christian K. <ck...@vx...>]

Hi there,

at first thanks for the good work. I stumbled over xSocket and
instantly loved it. ;)

So, I was starting to write a repeater service using SSL.
That means a client and a server both connect the repeater and
identify themselves either as being client or server and to whom
they belong. The result is a pair of two connections - similar to
the proxy example. (it's all about remote desktop stuff)

Everything is working fine - until some sporadic hang occurs in the
onData handler. Because it is non-threaded the whole server hangs.

The code:

	public boolean onData(INonBlockingConnection c)
		throws IOException, BufferUnderflowException,
MaxReadSizeExceededException {
		Node n = (Node)c.getAttachment();
		
		if(n != null && n.sessionID != null) {
			Node n2 = n.server ? viewers.get(n.sessionID) :
servers.get(n.sessionID);
			
			if(n2 != null) {
				System.out.print((n2.server ? "S" : "C") +
c.available() + ">");
				// before hang #1
				ByteBuffer[] data =
c.readByteBufferByLength(c.available());
				
				System.out.print("<" + (n2.server ? "S" :
"C"));
				// before hang #2
				n2.c.write(data);
				
				System.out.println("#");
			}
		}
		
		return true;
	}

I identified two positions where the code may hang. The write hangs far more
often than the
read. But as I said - sometimes it's running for hours, even days. In
another case it died
within 3 minutes. :(

Could anyone please give me a hint what to watch out for? What to tune?
I supposed some synchronisation cludge with the SSL stack and modified
xSocket, so that I
can deliver my own customized SSLEngine. I forced the connection to use RC4
stream-cipher,
because I thought there may be some length difference issue due to
padding/unpadding when
using a block-cipher - but nothing changed. :-/

Or do I simply _have to_ use multi-threading as soon as I want to have SSL?
Did I understand the other threads correctly, that I would have to
synchronize on the
connection objects for each read and write operation when using
multi-threading?

Thanks in advance.

Best regards,
Christian