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From: jans@tekchips.TEK.COM (Jan Steinman)
Newsgroups: comp.lang.smalltalk
Subject: Re: Re: Smalltalk for (embedded) real-time
Message-ID: <1691@tekchips.TEK.COM>
Date: Mon, 14-Sep-87 20:52:32 EDT
Article-I.D.: tekchips.1691
Posted: Mon Sep 14 20:52:32 1987
Date-Received: Wed, 16-Sep-87 06:32:17 EDT
Organization: Tektronix Inc., Beaverton, Or.
Lines: 22

<<<Very briefly, is there a general programming discipline that one can follow 
in the current Smalltalk-80   that will keep  you  from ever  seeing the  
garbage collection symbol come up while your  method is  running  ?   It seems 
that if your method doesn't call anything that allocates new space you  are 
set.>>>

The very act of "running your method" *potentially* creates a MethodContext 
object, which generally becomes garbage (unreferenced) as soon as the method is 
exited.  (*Potentially*, because all high-performance interpreters cache 
contexts, only creating bona-fide context objects when needed.)  If your method 
contains a block that is executed, you most certainly create a BlockContext 
object and one or more MethodContext objects, which become garbage 
(unreferenced objects) as soon as the block is exited, and are therefore 
subject to collection.

The quick answer is that there is no way to avoid creating garbage in 
Smalltalk-80, and  currently available Smalltalk-80 systems do not allow 
turning off the collection of that garbage.

:::::: Software Productivity Technologies    ---    Smalltalk   Project ::::::
:::::: Jan Steinman N7JDB	Box 500, MS 50-470	(w)503/627-5881 ::::::
:::::: jans@tekcrl.TEK.COM	Beaverton, OR 97077	(h)503/657-7703 ::::::