Path: chuka.playstation.co.uk!scea!peter_alau@playstation.sony.com
From: jamin1@psu.edu (Jamin Frederick)
Newsgroups: scea.yaroze.programming.2d_graphics
Subject: Re: I can't stand it anymore!
Date: Wed, 03 Jun 1998 22:58:45 GMT
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On Tue, 02 Jun 1998 15:51:12 -0700, Elliott Lee <tenchi@netmagic.net>
wrote:

>Jamin Frederick wrote:
>> 
>> On Tue, 02 Jun 1998 03:11:44 GMT, antony.arciuolo@mail.trincoll.edu
>> (Antony Arciuolo) wrote:
>> 
>> >I will ask the stupid question. How do you load files into main memory
>> >and prevent them from being overwritten by the code allocating memory?
>> >
>> 
>> When you malloc() memory, you're adding space to the heap, which grows
>> up from the (static) program code.  The stack, which grows down from
>> where you set it, is allocated from function calls and local
>> variables.  So what most people do is this:
>
>Although I wondered about that---whether the Yaroze stack is growing
>downwards or upwards because the docs stated that you the area between
>0x801f0000-0x801fffff was designated for stack.

	That is not the program stack, that area is the system stack
that the OS proprietarily uses.

> I would hope that for
>any malloc()-ing that is done, the amount of space is calculated
>before-hand as to not collide with the designated stack area.
>

	Yea, there's some methods to check to make sure this doesn't
happen.  If it does, the system will (probably) freeze.

>What I generally do is actually block off an area in my programming
>(not using malloc()) and make a note that it is a scratchpad area.
>e.g. 0x80090000-0x800b0000 is for game maps and manipulation of them.
>(Using #defines for this can also save a few cycles of pointer
>dereferencing.)
>
>> Stack (top of allowed yaroze space)
>>   |
>>   *
>> 
>> (hope stack & heap don't collide!)
>>
>>   *
>>   |
>> Heap
>> Code (Loaded above Data)
>> Data (Loaded @ 90080000 and up -- bottom of allowed yaroze space)
>> 
>> Jamin
>
>- e!
>  tenchi@netmagic.net
>  http://www.netmagic.net/~tenchi/yaroze/