Fix mailbox-empty-p for sbcl, add simple.lisp example

[CGenie]

This is useful for newbies like me.

[CGenie]

I also fixed this to work on lispworks on linux, as it seems the objc.lisp code was macos-only.

[dbmcclain]

I don't understand where the stress is in stresstest.lisp?

If it is intended to come from your possible Bignum, then have a look at the crypto that uses 256 bit integers and larger. It works fine because Lisp works fine.

[dbmcclain]

The SBCL fix is fine.

THe simple.lisp should not be using DEFPARAMETER on the Actors. That will eventually get you into trouble. DEFPARAMETER is a "Special Binding" in Lisp. We need "Lexical Bindings", like those of all Lisp Functions.

[CGenie]

I don't understand where the stress is in stresstest.lisp?

If it is intended to come from your possible Bignum, then have a look at the crypto that uses 256 bit integers and larger. It works fine because Lisp works fine.

Maybe it's incorrect naming. I just wanted to saturate my CPUs with something to compute.

[CGenie]

The SBCL fix is fine.

THe simple.lisp should not be using DEFPARAMETER on the Actors. That will eventually get you into trouble. DEFPARAMETER is a "Special Binding" in Lisp. We need "Lexical Bindings", like those of all Lisp Functions.

Thanks for this tip!