adding rsockets support into JDK

[Alan Bateman]

On 18/05/2018 17:06, Lu, Yingqi wrote:
> Thank you for your feedback, Alan!
>
> I will modify accordingly, update the JEP online and send a copy to jdk-dev for broader review.
>
I read through the updated JEP (in JDK-8203434) and it reads well now.

One suggestion is to split the Description so that the API is in its own 
section after the Description, and before Testing. That would give you a 
place to explain that the feature is platform specific / non-standard so 
the proposal is to add the API to the jdk.net module which is where 
JDK-specific networking features are exposed. The text you have after 
"Below is the list of proposed public APIs" can follow.

One other thing is Risk/Assumption #2 where 
-Djava.net.preferIPv4Stack=true is needed. We updated the implementation 
in JDK 7 to allow for mixing of IPv4 and IPv6 sockets in the same VM and 
I think you should be able to make use of that and avoid needing to 
force all sockets be IPv4 sockets. The example to look at is 
DatagramChannelImpl as you can create a DatagramChannel to an IPv4-only 
socket. In the RDMA SocketChannel/ServerSocketChannel implementations 
then you should be able to specify the protocol family to 
connect/accept. You don't need to do this in a first version of course 
but I think addressing this point will make it a lot more usable.

-Alan.