Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!rutgers!cbmvax!jesup
From: jesup@cbmvax.commodore.com (Randell Jesup)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: Good Programming stops guru |||| and BNF of C++
Message-ID: <17304@cbmvax.commodore.com>
Date: 9 Jan 91 21:17:24 GMT
References: <1806@winnie.fit.edu> <629@caslon.cs.arizona.edu>
Reply-To: jesup@cbmvax.commodore.com (Randell Jesup)
Organization: Commodore, West Chester, PA
Lines: 21

In article <629@caslon.cs.arizona.edu> dave@cs.arizona.edu (Dave P. Schaumann) writes:
>One thing you certainly want to watch is how you use memory you get from
>malloc.  I recently had a bug where I said 'malloc(foo)', when I really
>wanted 'malloc(foo * sizeof(int)'.  Naturally, in the first version, subsequent
>code stomped all over the memory past the allocated block.  Unfortunately,
>this contained information vital to the integrety of the free memory list.
>
>The result of this is at some time later (usually shortly after my program
>quit) my Amiga would crash and burn.  Usually with the 'memory freed twice'
>guru.

	Ah, you need MungWall!  Mungwall would catch that, and show you the
trashing (as well as mostly insulate the system from the error, unless you
went _way_ out of bounds).

-- 
Randell Jesup, Keeper of AmigaDos, Commodore Engineering.
{uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.commodore.com  BIX: rjesup  
The compiler runs
Like a swift-flowing river
I wait in silence.  (From "The Zen of Programming")  ;-)