[External] : Re: New candidate JEP: 471: Deprecate the Memory-Access Methods in sun.misc.Unsafe for Removal

[John Rose]

P.S. I didn’t directly address David’s request for that magic number N.
I would just assume 32 bits as the conservative element size (for oops)
and work from there.  If the cache line size is 64 bytes, then N=16.
These are robust assumptions, even if they waste a little space
when N could be 8 (because oops are 64 bits).  If the objects are
flattened, N=16 is still conservatively correct, as long as they
flatten to at least 4 bytes (which is very likely, and if not just
use a primitive array).  The same external considerations that
determine the D$ line size, to a value other than 64, can also
configure the parameter N, to a value other than 16.  That is
how I would build David’s widget without using Unsafe.