adding rsockets support into JDK

[Chris Hegarty]

> On 23 Nov 2018, at 13:54, Alan Bateman <Alan.Bateman at oracle.com> wrote:
> 
> On 21/11/2018 19:23, Lu, Yingqi wrote:
>> Hi Alan,
>> 
>> We can certainly remove IPv6 support for now if that makes the implementation cleaner. rsocket will be created with AF_INET regardless if IPv6 is supported or not.
>> 
> Do you have any insight into whether IPv4-mapped IPv6 addresses will be supported some day? This question is important because it the support never comes then the factory methods will always be limited to IPv4 (unless we get into dual socket hacks).

Please let’s agree to avoid dual-socket hacks at all costs. I have
firsthand experience of this from working with older Windows platforms.
If IPv4-mapped IPv6 address support is lacking or not on the relative-
near horizon ( for the particular rsocket implementation being used ),
then maybe the API factory methods should accept a `ProtocolFamily` to
selectively create a socket of a particular family. That way both IPv6
and IPv4 will be supported, just not in the same socket.

-Chris.