Reserving an extra slot on the stack

[coleen.phillimore at oracle.com]

On 1/25/18 9:59 AM, David Lloyd wrote:
> For an experiment I'm working on, I'd like to modify the JVM to
> reserve one reference-sized slot (which eventually should be visible
> to GC) on every stack frame at a fixed well-known offset (such that I
> can reach it via Unsafe from Java-space).  But it appears that the
> stack layout code is pretty deep in per-CPU areas.

Yes.
>    Is there a generic
> mechanism that I've missed?  Like some way to make the compiler act as
> if there were one extra local variable or something like that?

No.   The mirror is stored in the interpreter stack frame at a fixed 
offset so maybe you can use that as a model.

Coleen
>