Code Review 6921111: NullPointerException in PlainDatagramSocketImpl.socketSetOption

[Christopher Hegarty - Sun Microsystems Ireland]

Hi Michael, Alan,

This is a very small change to fix a problem in native code where, if 
multiple threads are executing the native method, an unset value of a 
static variable may be used. When setting static variables in a block we 
can only be sure they are all set when the last one is. This is a common 
pattern in the socket impl native code.

I plan to clean up this area of native code and remove unnecessary 
duplicate static state, but for now I just want to resolve this specific 
bug.

Webrev:
   http://cr.openjdk.java.net/~chegar/6921111/webrev.00/webrev/

Thanks,
-Chris.