RFR:8170868: DefaultProxySelector should use system defaults on Windows, MacOS and Gnome

[Chris Hegarty]

Arno,

> On 27 Dec 2016, at 11:44, Zeller, Arno <arno.zeller at sap.com> wrote:
> 
> Hi Chris,
> 
> Thanks for having a look at my change:
> 
>> 1) It seems awful to have to deal with LinkedList in native code. How
>>   about returning an array from native, and then converting that into
>>   whatever list type is appropriate at the Java level.
> With the current implementation on Mac I do not know upfront how many items the list will contain and therefore I preferred to use the LinkedList from native code.
> I can of course change the implementation on Mac to first generate a fully resolved native list and then I can use NewObjectArray to generate an Array of Proxy objects to return. This will avoid calling to java to add an element to the list. Do you think this will be better?

Yes. Thanks.

>> 2) I would prefer the use of List.of(...), and list.of() for empty, since
>>   these are immutable and efficient list implementations.
> I thought about that but I tried to not return an immutable List because the Javadoc of Proxy.select does not state anything about the returned List (if it is immutable or not) and I feared to break compatibility by returning an immutable List. 
> If you think this is no problem I will of course prefer to always return the same immutable NO_PROXY list object.

I would prefer an immutable list. Maybe we file, a separate, issue to
amend the spec to say "returns an immutable list …”.

>> 3) Is the comment “Inspired ...” necessary / appropriate?
> I will change it to the comment proposed by Volker.

Ok.

>> 4) Can some of the native initialization code be moved to a platform
>>   independent location, to remove duplication?
> Would it be ok if I move the definition of the static variables and the implementation of 'static int initJavaClass(...)' to a header file in the shared branch. I.e. src/java.base/shared/native/libnet/DefaultProxySelector.h and include this in the MacOSX, Windows and the Unix implementations?

Yes.

>> 5) The new file has a shared copyright header. I see similar SAP
>>   headers in a few files, but none shared with the Oracle header.
>>   How did you arrive at this format?
> The format was suggested to me by Volker :-)

Ok.

-Chris.