adding rsockets support into JDK

[Chris Hegarty]

On 19/11/18 17:25, Lu, Yingqi wrote:
> Hi Alan/Chris/Brian,
> 
> Thank you very much for your help on finalizing the CSR. Really appreciate!
> 
> I modified JEP accordingly at 
> https://bugs.openjdk.java.net/browse/JDK-8203434
> 
> The most recent version of the patch is available at 
> http://cr.openjdk.java.net/~ylu/8195160.17/ 
> <http://cr.openjdk.java.net/%7Eylu/8195160.17/>

Still reviewing, some passing comments:

- src/java.base/share/classes/module-info.java
   I don't think that the `opens java.net to jdk.net` is still needed.

- The changes in src/jdk.net/share/classes/jdk/net/Sockets.java can be
   removed.

- The tests all follow a pattern similar to the following:

     if (!RsocketTest.isRsocketAvailable())
         return;

   , which is fine. More recently we've been preferring to throw a jtreg
   specific exception to indicate that the test was skipped, rather than
   run. The exception is jtreg.SkippedException. For example look at the
   usage in PromiscuousIPv6 [1].

- Must the tests be run with `-Djava.net.preferIPv4Stack=true` ? I
   understand that IPv6 is not supported in the rsocket implementation,
   but just curious if the system property is strictly needed?

-Chris.

  [1] 
http://hg.openjdk.java.net/jdk/jdk/file/tip/test/jdk/java/nio/channels/DatagramChannel/PromiscuousIPv6.java