Incompatibility between 1.4.1 and 1.4.2

Question

We have been developing under JDK1.4.1 for some time, and now need to move to JDK1.4.2, but have run into a problem when attempting to run under 1.4.2
1) code compiled under 1.4.1 does not run under 1.4.2
2) code that compiled and ran under 1.4.1, when compiled with 1.4.2 does not run under 1.4.2.
3) code compiled under 1.4.1 ran correctly under 1.4.1 on both unix and windows
4) attempting to run under 1.4.2 fails on both unix and windows
I have isolated the problem down to a simple test where a client sends a login request to a server:
a) under 1.4.1 the client sends the login request and the server receives it
b) under 1.4.2, the client should send the login request, but the server never receives the request
The server creates a ServerSocket and calls accept on a seperate thread waiting for accept to complete, which it does in both 1.4.1 and 1.4.2
The client sits in a wait loop waiting to be interrupted:
in 1.4.1 it does get interrupted (this.wait() is interrupted and catch clause catches InterruptedException)
in 1.4.2 it does NOT get interrupted (this.wait() hangs indefinitely)
synchronized(this) {
while (((ClientSocketConnection)getConnection()).isClosed()) {
try {
getTracer().message(this, "start", "Wait until notified of start");
this.wait();
} catch (InterruptedException e) {}
getTracer().message(this, "start", "Lets check if we are connected");
if (((ClientSocketConnection)getConnection()).isClosed())
throw new ProtocolException("Could not connect "+connectionId+". Check configuration");
Ok, the details are a bit sketchy, but I wondered if anyone has had anything similar / can shed any light / can point me in the right direction
After a bit more digging around, I find that the actual code line that is hanging is in another class, and is the API 'register' call on java.nio.channels.SocketChannel class
The code is attempting to set the channel associated with the socket connection to be read/writable and makes the call
socketChannel.register(selector, SelectionKey.OP_WRITE | SelectionKey.OP_READ, socketConnection);
- where
socketChannel is a java.nio.channels.SocketChannel
selector is a java.nio.channels.Selector
socketConnection is our own class representing the socket connection
This call completes and returns in 1.4.1, but hangs in 1.4.2
Anyone got any ideas or run into something similar
Thanks

Answer 1

Just some remarks.
Might need to undo the synchronized before the wait.
You might have a channel involved: see javadoc on isBlocking and blockingLock.