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

[Langer, Christoph]

Hi Vyom,

what about my suggestions for renaming?

src/jdk.net/macosx/classes/jdk/net/UnixSocketOptions.java -> src/jdk.net/macosx/classes/jdk/net/MacOSXSocketOptions.java
src/jdk.net/macosx/native/libextnet/UnixSocketOptions.c -> src/jdk.net/macosx/native/libextnet/MacOSXSocketOptions.c

This would be more consistent as we have:
src/jdk.net/linux/native/libextnet/LinuxSocketOptions.c
src/jdk.net/linux/classes/jdk/net/LinuxSocketOptions.java
...
src/jdk.net/solaris/native/libextnet/SolarisSocketOptions.c
src/jdk.net/solaris/classes/jdk/net/SolarisSocketOptions.java

Thanks
Christoph

> -----Original Message-----
> From: net-dev [mailto:net-dev-bounces at openjdk.java.net] On Behalf Of
> vyom tewari
> Sent: Montag, 23. April 2018 14:06
> To: Chris Hegarty <chris.hegarty at oracle.com>; OpenJDK Network Dev list
> <net-dev at openjdk.java.net>
> Subject: Re: RFR:8194298 Add support for per Socket configuration of TCP
> keepalive
> 
> Hi,
> 
> Please find the latest
> webrev(http://cr.openjdk.java.net/~vtewari/8194298/webrev0.1/index.htm
> l).
> I incorporated  most of the review comments.
> 
> Thanks,
> 
> Vyom
> 
> 
> On Wednesday 18 April 2018 07:44 PM, Chris Hegarty wrote:
> > Vyom,
> >
> > On 13/04/18 10:50, vyom tewari wrote:
> >> 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
> >
> > Here is some proposed wording for the JDK-specific extended socket
> > options specification.
> >
> > 1) Uses a consistent style across all three new options,
> >    and is in line with existing extended options.
> > 2) Renamed the options slightly, to improve readability
> >    ( they don't need to conform to the native option names )
> > 3) Reordered them so the build up is more logical
> > 4) Removed inheritance from server sockets
> > 5) Added standard verbiage about being "platform and
> >    system dependent
> > 6) Added typical values. I think this is useful, as it
> >    gives an idea to the developer, but maybe it could be
> >    misleading. Can be dropped if there are concerns.
> >
> > Can you please confirm that this is accurate, and also
> > will leave enough "wriggle" room when additional platform
> > support is added.
> >
> > ---
> >
> >     /**
> >      * Keep-Alive idle time.
> >      *
> >      * <p> When the {@link java.net.StandardSocketOptions#SO_KEEPALIVE
> >      * SO_KEEPALIVE} option is enabled, TCP probes a connection that
> > has been
> >      * idle for some amount of time. The default value for this idle
> > period is
> >      * system dependent, but is typically 2 hours. The {@code
> > TCP_KEEPIDLE}
> >      * option can be used to affect this value for a given socket.
> >      *
> >      * <p> The value of this socket option is an {@code Integer} that
> > is the
> >      * number of seconds of idle time before keep-alive initiates a
> > probe. The
> >      * socket option is specific to stream-oriented sockets using the
> > TCP/IP
> >      * protocol. The exact semantics of this socket option are socket
> > type and
> >      * system dependent.
> >      *
> >      *  @since 11
> >      */
> >     public static final SocketOption<Integer> TCP_KEEPIDLE
> >             = new ExtSocketOption<Integer>("TCP_KEEPIDLE",
> > Integer.class);
> >
> >     /**
> >      * Keep-Alive retransmission interval time.
> >      *
> >      * <p> When the {@link java.net.StandardSocketOptions#SO_KEEPALIVE
> >      * SO_KEEPALIVE} option is enabled, TCP probes a connection that
> > has been
> >      * idle for some amount of time. If the remote system does not
> > respond to a
> >      * keep-alive probe, TCP retransmits the probe after some amount
> > of time.
> >      * The default value for this retransmition interval is system
> > dependent,
> >      * but is typically 75 seconds. The {@code TCP_KEEPINTERVAL}
> > option can be
> >      * used to affect this value for a given socket.
> >      *
> >      * <p> The value of this socket option is an {@code Integer} that
> > is the
> >      * number of seconds to wait before retransmitting a keep-alive
> > probe. The
> >      * socket option is specific to stream-oriented sockets using the
> > TCP/IP
> >      * protocol. The exact semantics of this socket option are socket
> > type and
> >      * system dependent.
> >      *
> >      * @since 11
> >      */
> >     public static final SocketOption<Integer> TCP_KEEPINTERVAL
> >             = new ExtSocketOption<Integer>("TCP_KEEPINTERVAL",
> > Integer.class);
> >
> >     /**
> >      * Keep-Alive retransmission maximum limit.
> >      *
> >      * <p> When the {@link java.net.StandardSocketOptions#SO_KEEPALIVE
> >      * SO_KEEPALIVE} option is enabled, TCP probes a connection that
> > has been
> >      * idle for some amount of time. If the remote system does not
> > respond to a
> >      * keep-alive probe, TCP retransmits the probe a certain number of
> > times
> >      * before a connection is considered to be broken. The default
> > value for
> >      * this keep-alive probe retransmit limit is system dependent, but is
> >      * typically 8. The {@code TCP_KEEPCOUNT} option can be used to
> > affect
> >      * this value for a given socket.
> >      *
> >      * <p> The value of this socket option is an {@code Integer} that
> > is the
> >      * maximum number of keep-alive probes to be sent. The socket
> > option is
> >      * specific to stream-oriented sockets using the TCP/IP protocol.
> > The exact
> >      * semantics of this socket option are socket type and system
> > dependent.
> >      *
> >      * @since 11
> >      */
> >     public static final SocketOption<Integer> TCP_KEEPCOUNT
> >             = new ExtSocketOption<Integer>("TCP_KEEPCOUNT",
> > Integer.class);
> >
> > -Chris.