RFR:8194298 Add support for per Socket configuration of TCP keepalive

[Langer, Christoph]

Hi Vyom,

I had a quick glance through your changes.

Apart from the suggestions you've already got (use snprintf instead of string concatenation, method ordering...), I think "src/jdk.net/macosx/classes/jdk/net/UnixSocketOptions.java" and " src/jdk.net/macosx/native/libextnet/UnixSocketOptions.c " should be renamed to MacOSXSocketOptions.<java/c> to be consistent with the other platforms (Linux and Solaris at the moment).

Furthermore, I think most of the options can/should also be supported for AIX. I'm willing to contribute this. However, I should probably do this in a separate bug once you have completed your work on this one. I would also add TCP QUICKACK then.

Best regards
Christoph

> -----Original Message-----
> From: net-dev [mailto:net-dev-bounces at openjdk.java.net] On Behalf Of
> vyom tewari
> Sent: Freitag, 13. April 2018 11:51
> To: OpenJDK Network Dev list <net-dev at openjdk.java.net>
> Subject: RFR:8194298 Add support for per Socket configuration of TCP
> keepalive
> 
> Hi All,
> 
> Please review the below code.
> 
> BugId    : https://bugs.openjdk.java.net/browse/JDK-8194298
> 
> webrev :
> http://cr.openjdk.java.net/~vtewari/8194298/webrev0.0/index.html
> 
> Currently Java supports SO_KEEPALIVE, whose default value is 7200
> seconds which is too long for most of the applications. This code change
> will allow us to set the keepalive
> parameters(TCP_KEEPIDLE,TCP_KEEPCNT,TCP_KEEPINTVL)  which will
> configure
> the idle time on per socket basis.
> 
> I did code changes for Linux & Mac only, support for other platforms can
> be added in future if needed.
> 
> Thanks,
> 
> Vyom