Jeroen Frijters writes:
> Andrew Haley wrote:
> > The current gnu.classpath.VMStackWalker interface is inefficient.
> >
> > Sun provide:
> >
> > sun.reflect.reflection.getCallerClass(int depth)
> >
> > and for the same function we would do
> >
> > VMStackWalker.getClassContext()[depth];
> >
> > You see the difference: Classpath's VMStackWalker enumerates the whole
> > stack, whereas Sun's only has to enumerate a few stack frames.
>
> Actually, Sun simply has a bad design. There is no need for arbitrary
> depth caller class discovery (as our codebase demonstrates).
How, exactly? I see horrors like
/**
* Get the class loader associated with the Class returned by
* <code>getCallingClass()</code>, or <code>null</code> if no such class
* exists or it is the boot loader. This method is an optimization for the
* expression <code>VMStackWalker.getClassLoader(getClassContext()[1])</code>
* and should return the same result.
*
* <p>
* VM implementers are encouraged to provide a more efficient
* version of this method.
*/
public static ClassLoader getCallingClassLoader()
{
Class[] ctx = getClassContext();
if (ctx.length < 3)
return null;
return getClassLoader(ctx[2]);
}
in several places.
> However, now that we've got the reference j.u.c implementation it
> makes sense to add a method to VMStackWalker that enables us to
> more efficiently implement sun.reflect.reflection.getCallerClass.
Right.
Andrew.
