From: nobu.nokada@...
Date: 2003-07-03T02:48:41+09:00
Subject: Re: rb_gc() and scan stack

Hi,

At Thu, 3 Jul 2003 01:00:35 +0900,
Simon Strandgaard wrote:
> What confuses me is that 'G' is right-most in step 1-6.
> And that 'G' is left-most in step 7a.
> This seems odd to me, Is this really correct behavier ?

It *was* correct.  To be accurate, nothing shouldn't be marked
in step 2 through 6.  But rb_gc_mark_locations(), which marks
stack, swaps its arguments when they are out of order.  So
garbages would possibly be marked.

# I forgot to remove this now useless code.

> I should have mentionen that I am talking about a x86 stack 
> which grows downward. In my posting the stack therefore had
> its high-addeses to the left.. and the lower addesses at right.
> I see you have swapped 'bottom' with 'top'.. this confuses me.
> Are you refering to a x86 stack or a motorola stack ?

Both x86 and mc68000 stacks grow downward.  IIRC, beginning of
stack is called "bottom", and the edge where an element is
pushed into and popped from is called "top".

-- 
Nobu Nakada