hmmm? no that was not my intent.

No I assume at some stage the ruby block has to be turned into a C block with associated scope - and from my limited knowledge on GCD that does not seem so easy. 

But Ernie - I'd love for you to explain how its all done! ;-).

I mean if you have the time - it would be great to know maybe on pseudo code/architectural level how it all works. ruby block to c block, __block vars, scope etc, etc, I am a bit scratching in the dark here.

Cheers,

John