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From: ewhac@well.UUCP (Leo L. Schwab)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Unsupported Programming Practices
Summary: Poo...
Message-ID: <10262@well.UUCP>
Date: 7 Jan 89 07:31:32 GMT
References: <5605@cbmvax.UUCP> <10227@well.UUCP> <5632@cbmvax.UUCP>
Reply-To: ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab)
Organization: (-: ACME Flamethrowers.  Mark Ethan Smith, CEO. :-)
Lines: 34
Quote: "Hip! Hip! Hooray!  We're orphans!"  -- Dynaman

In article <5632@cbmvax.UUCP> steveb@cbmvax.UUCP (Steve Beats) writes:
>In article <10227@well.UUCP> ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) writes:
>>In article <5605@cbmvax.UUCP> carolyn@cbmvax.UUCP (Carolyn Scheppner CATS) writes:
>>>Do not execute code on your stack or put system structures on your stack.
>>	I occasionally put RastPorts on my stack; does that count?
>>
>Yes that certainly does count.  If Exec ever gets its act together and starts
>using the MMU, your stack would be private memory.  If graphics attempted to
>access the RastPort (as a separate task through Intuition for instance) it 
>would cause an illegal access exception.  I would suggest you either:-
>
>a)	Allocate rastports using MEMF_PUBLIC
>b)	Allocate a new stack using MEMF_PUBLIC
>
	AARRGGHHH!  What a bloody nuisance.  Throwing temproary RastPorts
around on the stack has been a real nice win for me.  I've been doing things
like this:

	if (loadILBM() == SUCCESS) {
		struct RastPort	lrp;

		InitRastPort (&lrp);
		lrp.BitMap = &loaded_bitmap;
		ClipBlit (&lrp, 0L, 0L, &dest, 0L, 0L, w, h, MINTERM_COPY);
	}

	So now I have to do AllocMem()s with sanity checks with
corresponding FreeMem()s?  Foo.

_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
Leo L. Schwab -- The Guy in The Cape	INET: well!ewhac@ucbvax.Berkeley.EDU
 \_ -_		Recumbent Bikes:	UUCP: pacbell > !{well,unicom}!ewhac
O----^o	      The Only Way To Fly.	      hplabs / (pronounced "AE-wack")
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