RFR 8195059: Update java.net Socket and DatagramSocket implementations to use Cleaner

[Roger Riggs]

Adding net-dev at openjdk.java.net

On 1/30/2018 5:08 PM, Roger Riggs wrote:
> Please review changes to replace finalizers in socket, datagram, and 
> multicast networking
> with Cleaner based release of the raw file descriptors.  Each 
> FileDescriptor is registered
> for cleanup after the raw fd (or handle) is assigned.  Normal calls to 
> close unregister the
> cleaner before using the current logic to close the raw fd/handle. 
> Windows networking
> uses fd's with the Windows socket_ API requiring a special cased 
> Cleanable.
>
> The tests check that the implementation objects including 
> FileDescriptors are reclaimed
> and for Linux that the raw fd counts are reduced as expected.
>
> Webrev:
>    http://cr.openjdk.java.net/~rriggs/webrev-net-cleanup-8195059/
>
> Thanks, Roger
>
>