First draft of translation document

[Neal Gafter]

On Wed, May 19, 2010 at 2:35 AM, Rémi Forax <forax at univ-mlv.fr> wrote:
>> These frame objects are not stack allocated.  They must be managed by
>> the GC.  Thus, an object header is required.
>
> The whole point of asSam() is to try to avoid the static footprint that you
> currently have with anonymous classes.
> If the frame object is not know by the VM, the compiler have to generate a
> specific class for each frame object
> thus we are falling in the same trap as anonymous classes.

I don't know what you mean by "known by the VM", or how a separate VM
feature could make any difference, since these frame object must be
heap allocated.  Perhaps you're advocating some kind of structural
types at the VM level?

> The problem with shared variables is that you break the assumption
> that you have sequential ordering of local variables.
> I don't see why we should offer a feature with such semantics.
>
> void f() {
>  shared String s = "hello";
>  Utils.perhapsRunInAnotherThread(#() {
>    System.out.println(s); // may or may not prints null
>  });
> }

The initialization of the variable s "happens before" the thread is
even created, so there is no race condition.  This program always
prints "hello".  This is no different than if s had been a field.