[Python-Dev] stack check on Unix: any suggestions?

[Thomas Wouters]

On Tue, Aug 29, 2000 at 03:12:57PM -0500, Skip Montanaro wrote:

> On most (all?) processors in common usage, the stack grows down toward the
> heap and the heap brows upward, so what you really want to do is detect that
> collision.  brk and sbrk are used to manipulate the end of the heap.  A
> local variable in the current scope should be able to tell you roughly where
> the top of stack is.

I don't think that'll help, because the limit isn't the actual (physical)
memory limit, but mostly just administrative limits. 'limit' or 'limits',
depending on your shell.

> current top of stack.  If obmalloc brks() memory back to the system (I've
> never looked at it - I'm just guessing) it could lower the saved value to
> the last address in the block below the just recycled block.

Last I looked, obmalloc() worked on top of the normal system malloc (or its
replacement if you provide one) and doesn't brk/sbrk itself (thank god --
that would mean nastiness if extention modules or such used malloc, or if
python were embedded into a system using malloc!)

-- 
Thomas Wouters <thomas@xs4all.net>

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