RFR[8239355]: '(dc) Initial value of SO_SNDBUF should allow sending large datagrams (macOS)'

[Patrick Concannon]

Hi,

Could someone please review my fix for JDK-8239355 '(dc) Initial value 
of SO_SNDBUF should allow sending large datagrams (macOS)' ?

By default, macOS imposes a size of 9216on Datagrams which limits 
applications that don't set the SO_SNDBUF option - legacy DatagramSocket 
sets the value to 65507 at creation time.
This fix updates DatagramChannel so that the SO_SNDBUF is set to a 
minimum value of 65527 for IPv6 sockets and 65507 for IPv4 sockets on 
macOS.


bug: https://bugs.openjdk.java.net/browse/JDK-8239355
webrev: 
http://cr.openjdk.java.net/~pconcannon/8239355/webrevs/webrev.00/index.html

Kind regards,

Patrick