adding rsockets support into JDK

[Chris Hegarty]

> On 29 Nov 2018, at 13:41, Alan Bateman <Alan.Bateman at oracle.com> wrote:
> 
> On 28/11/2018 21:42, Lu, Yingqi wrote:
>> Hi Chris,
>> 
>> I have already updated the version 20 with your changes. I also removed several redundant test cases. The updated version of patch is available at: https://cr.openjdk.java.net/~ylu/8195160.20/
>> 
>> Would you please review the changes especially the changes regarding to the protocol family? This way, we can finalize the CSR soon.
> I read through the updated API/javadoc. Just a few comments:
> 
> - the class description still links to the no-arg factory methods
> - the @implNote says that only IPv4 is supported so I assume the notes can be removed now
> - we should probably specify NPE for the corner case that family is null. A paragraph in the class description or @throws NPE in the 4 methods is okay, either approach will do

I agree with Alan's comments. Additionally,

1) What is the behaviour, and does it need to be specified, if a socket
   of one family type is either bound or connected to an address of a
   different family type?

2) Socket has a connect method that accepts a String host name, will
   the lookup of the host prefer IPv6 addresses when the Socket's family
   type is INET6?

-Chris

P.S. I'm still struggling to setup a test environment to run this code,
otherwise I would try to answer some of these questions myself.