After several iterations of changing the interetOps on a single key,
the system begins to spin:
    the cnt returns from select = 1
    but the set of selectedKeys is empty

I am attaching a test case which demonstrates the problem.


I'm changing interestOps because I need a way to:

- prevent two threads from reading or writing on the
  same channel at the same time [ message order restrictions
  on the server]

- I dont want to spin when the socket is available for writin
  but I have no data to write

- I cant have seperate keys for read and write and cancel
   them seperately (because of problems on windows)

 ----------------------
To run the test case:
   compile both files
   Run Server (receives messages and sends them back to the client)
   Run Client (sends messages to the server)

When the error occurs, you should see something like:

ERROR: System is spinning ..
1001 iterations of errors
Cnt from select = 1 doesnt match keys.size() 0