From: "Vladimir Olensky" <vladimir_olensky@yahoo.com>
Subject: Ada and GC. Was: Re: Ammo-zilla
Date: 1999/11/01
Date: 1999-11-01T00:00:00+00:00 [thread overview]
Message-ID: <s1r1j5psqof50@corp.supernews.com> (raw)
In-Reply-To: 7vht9i$a2g1@news.cis.okstate.edu
David Starner wrote in message <7vht9i$a2g1@news.cis.okstate.edu>...
>On Sun, 31 Oct 1999 13:26:48 GMT, Robert Dewar <robert_dewar@my-deja.com>
wrote:
>>What for instance does it mean to do address overlays that
>>reference the address of some object if the address of that
>>object changes due to GC? I have no idea what a sensible answer
>>to this question might be!
>
>Um, don't move it? Either pick a form of GC that doesn't move objects
>(the Boehm conservative GC is one that almost becoming the standard
>for free software, while GCC now uses a rather more sophisticated GC
>internally that doesn't move stuff), or mark that object as immobile.
Such problem exists only in the systems where everything
is garbage collected.
1. In a system that gives you a choice to use TRACED or UNTRACED
by GC objects just do not use TRACED objects if you don't want
them to be moved by GC from one memory location to another.
Ada 95 is a system that was designed to allow that.
2. Even if object is TRACED by GC it is possible to use a scheme
that does not modify memory reference of the TRACED object that
is visible to client.
Such scheme may use Address Descriptor Table for indirect object
reference within GC managed storage pool. This table is part of the
GC storage pool manager.
Each entry of such table could keep actual memory location of the
referenced
object and all the additional information that is needed to manage that
object.
( e.g - Ref_Count field for simple reference counting GC).
With such approach client knows only address of Address Descriptor Table
entry
for that particular object and the last one does not change when object is
moved to
the new memory location.
There is nothing new in that. It is similar to the protected memory
access
in operating systems that run in a protected mode. Address of the object
is
just address of the descriptor table entry for that object and the system
itself
calculates actual memory address of the referenced object.
What is more important such approach provides single_ point_ of_ access
for TRACED by GC objects. This in turn could make many things more easy.
Regards,
Vladimir Olensky
next prev parent reply other threads:[~1999-11-01 0:00 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-10-23 0:00 Ammo-zilla Stanley R. Allen
1999-10-24 0:00 ` Ammo-zilla Aidan Skinner
1999-10-24 0:00 ` Ammo-zilla Robert Dewar
1999-10-24 0:00 ` Ammo-zilla Matthew Heaney
1999-10-24 0:00 ` Ammo-zilla Aidan Skinner
1999-10-25 0:00 ` Ammo-zilla Jean-Pierre Rosen
1999-10-24 0:00 ` Ammo-zilla David Botton
1999-10-28 0:00 ` Ammo-zilla Charles Hixson
1999-10-28 0:00 ` Ammo-zilla Laurent Guerby
1999-10-28 0:00 ` Ammo-zilla Charles Hixson
1999-10-29 0:00 ` Ada and GC (Was Re: Ammo-zilla) Vladimir Olensky
1999-10-29 0:00 ` David Botton
1999-10-31 0:00 ` Vladimir Olensky
1999-10-30 0:00 ` Samuel T. Harris
1999-10-30 0:00 ` David Botton
1999-10-28 0:00 ` Ammo-zilla David Starner
1999-10-29 0:00 ` Ammo-zilla Larry Kilgallen
1999-10-29 0:00 ` Ammo-zilla David Starner
1999-10-29 0:00 ` Ammo-zilla Matthew Heaney
1999-10-29 0:00 ` Ammo-zilla Charles Hixson
1999-10-29 0:00 ` Ammo-zilla David Botton
1999-10-29 0:00 ` Ammo-zilla mike
1999-10-29 0:00 ` Ammo-zilla David Botton
1999-10-31 0:00 ` Ammo-zilla Robert Dewar
1999-11-02 0:00 ` Ammo-zilla Charles Hixson
1999-11-03 0:00 ` Ammo-zilla Wes Groleau
1999-11-01 0:00 ` Ammo-zilla Geoff Bull
1999-10-29 0:00 ` Ammo-zilla Tucker Taft
1999-10-30 0:00 ` Ammo-zilla Lutz Donnerhacke
1999-10-31 0:00 ` Ammo-zilla Robert Dewar
1999-10-31 0:00 ` Garbage colletion Lutz Donnerhacke
1999-11-01 0:00 ` Robert Dewar
1999-11-01 0:00 ` Lutz Donnerhacke
1999-11-01 0:00 ` Robert Dewar
1999-11-01 0:00 ` Lutz Donnerhacke
1999-11-01 0:00 ` Robert Dewar
1999-11-04 0:00 ` Didier Utheza
1999-11-04 0:00 ` David Starner
1999-11-01 0:00 ` Gnat IDE (was: Garbage colletion) Ted Dennison
1999-11-01 0:00 ` Garbage colletion Larry Kilgallen
1999-10-31 0:00 ` Ammo-zilla Robert Dewar
1999-10-31 0:00 ` Ammo-zilla David Starner
1999-11-01 0:00 ` Vladimir Olensky [this message]
1999-11-01 0:00 ` Ada and GC. Was: Ammo-zilla Vladimir Olensky
1999-11-01 0:00 ` Tucker Taft
1999-11-02 0:00 ` Vladimir Olensky
1999-11-02 0:00 ` Robert Dewar
1999-11-02 0:00 ` Charles Hixson
1999-11-03 0:00 ` Robert Dewar
1999-11-03 0:00 ` Charles Hixson
1999-11-01 0:00 ` Ammo-zilla Robert Dewar
1999-11-01 0:00 ` Ammo-zilla Robert Dewar
1999-11-01 0:00 ` Ammo-zilla Robert A Duff
1999-11-01 0:00 ` Ammo-zilla Robert Dewar
1999-11-02 0:00 ` Ammo-zilla Robert A Duff
1999-11-02 0:00 ` Ammo-zilla Robert Dewar
1999-11-03 0:00 ` Ammo-zilla Vladimir Olensky
1999-11-03 0:00 ` Ammo-zilla Robert Dewar
1999-11-04 0:00 ` Ada GC (was Re: Ammo-zilla) Vladimir Olensky
1999-11-06 0:00 ` Robert Dewar
1999-11-06 0:00 ` Vladimir Olensky
1999-11-06 0:00 ` Vladimir Olensky
1999-11-06 0:00 ` Robert Dewar
1999-11-09 0:00 ` Robert A Duff
1999-11-10 0:00 ` Vladimir Olensky
1999-11-10 0:00 ` Richard D Riehle
1999-11-10 0:00 ` Nick Roberts
1999-11-12 0:00 ` Robert Dewar
1999-11-12 0:00 ` Robert I. Eachus
1999-11-12 0:00 ` Didier Utheza
1999-11-10 0:00 ` Robert A Duff
1999-11-12 0:00 ` Robert I. Eachus
1999-11-04 0:00 ` Ada GC (was Ammo-zilla) Nick Roberts
1999-11-04 0:00 ` Wes Groleau
1999-11-01 0:00 ` Ammo-zilla Vladimir Olensky
1999-10-30 0:00 ` Ammo-zilla Lutz Donnerhacke
1999-10-30 0:00 ` Ammo-zilla Matthew Heaney
1999-10-31 0:00 ` Ammo-zilla Robert Dewar
1999-10-29 0:00 ` Ammo-zilla Robert I. Eachus
1999-10-28 0:00 ` Ammo-zilla Tucker Taft
1999-10-31 0:00 ` Ammo-zilla Brian Rogoff
1999-11-01 0:00 ` Ammo-zilla Robert Dewar
1999-11-01 0:00 ` Ammo-zilla Brian Rogoff
1999-11-02 0:00 ` Ammo-zilla Robert Dewar
1999-11-02 0:00 ` Ammo-zilla Brian Rogoff
1999-11-02 0:00 ` Ammo-zilla Robert A Duff
1999-10-28 0:00 ` Ammo-zilla Matthew Heaney
1999-10-28 0:00 ` Ammo-zilla mitch
1999-10-29 0:00 ` Ammo-zilla Matthew Heaney
1999-10-31 0:00 ` Ammo-zilla Robert Dewar
1999-10-24 0:00 ` Ammo-zilla Robert Dewar
1999-10-24 0:00 ` Ammo-zilla David Botton
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