Jeroen Frijters writes:
> Andrew Haley wrote:
> > > "jbyte" must have a single platform-specific definition, as all
> > > JVMs on that platform should be able to execute the same JNI
> > > library code (no recompilation required).
> >
> > I didn't know that. Is that requirement documented anywhere? I can't
> > see how you'd do it on a machine with 32-bit and 64-bit modes, for
> > example.
>
> Platform = Machine + OS. I don't have any reference, but I believe that
> Etienne is right in saying that the same library should be usuable with
> all JVMs on a specific platform.
But it's not necessarily possible. Clearly it's desirable, no
argument there.
> > Clearly the highest performance comes from using a naked long.
>
> No, the highest performance comes from using a platform specific
> pointer.
> I think that for a JIT it is easier to replace a typed object
> reference with a native pointer then a long. That's why I'm very
> much in favor of using RawData. It can even be abstract, that way
> the JNI layer can allocate sub types that contain the appropriate
> number of bits to contain a native pointer.
>
> For example:
>
> public abstract class RawData {}
>
> public final class RawData32 extends RawData
> {
> private int pointer;
> }
>
> public final class RawData64 extends RawData
> {
> private long pointer;
> }
>
> All the Java code would ever see are RawData references, but the JNI
> layer knows that all RawData references are actually 32 or 64 bit (or
> whatever that platform requires).
This seems to be identical to my proposal.
I no longer understand what we're arguing about...
Andrew.
_______________________________________________
Classpath mailing list
[EMAIL PROTECTED]
http://mail.gnu.org/mailman/listinfo/classpath
