From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Garbage collection (was a spinoff of a spinoff of a GA diatribe)
Date: 1996/10/27
Date: 1996-10-27T00:00:00+00:00 [thread overview]
Message-ID: <dewar.846422447@merv> (raw)
In-Reply-To: JSA.96Oct25133948@alexandria
Someone (I lost track) gave as an advantage of garbage collection:
> > Pro: ...
> > Faster - allocations can be _much_ faster and collections can be
> > much more efficient than good ol' "free".
I agree on the allocation, but the free claim is dubious, it depends on
a lot of factors. A true GC, as opposed to a conservative GC, can be
made to run in time proportional to the amount of non-garbage (see for
example the description of the SPITBOL collector in SP&E 1977 article
by Dewar and McCann), so if you have a LOT of garbage this can be true.
But if you are doing lots of GC's then you can end up spending a lot of
time freeing a little stuff (ttrue of conservative GC as well of course).
On the other hand, it is quite possible to make free quite efficient.
I wrote the collector for the x86 Alsys compiler (I don't know if the
TSP ObjectAda still uses it or not), and it had the property that
free was a single instruction that was generated in line.
next prev parent reply other threads:[~1996-10-27 0:00 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-10-21 0:00 Garbage collection (was a spinoff of a spinoff of a GA W. Wesley Groleau (Wes)
1996-10-22 0:00 ` Jon S Anthony
1996-10-25 0:00 ` Jon S Anthony
1996-10-27 0:00 ` Robert Dewar [this message]
1996-10-25 0:00 ` Robert I. Eachus
1996-10-24 0:00 ` Garbage collection (was a spinoff of a spinoff of a GA diatribe) Hans-Juergen Boehm
1996-10-25 0:00 ` Robert A Duff
1996-10-25 0:00 ` Hans-Juergen Boehm
1996-10-25 0:00 ` Brian R. Hanson
1996-10-30 0:00 ` Jon S Anthony
1996-10-30 0:00 ` Robert Dewar
1996-10-31 0:00 ` Jon S Anthony
-- strict thread matches above, loose matches on Subject: below --
1996-10-17 0:00 Garbage collection (was a spinoff of a spinoff of a GA W. Wesley Groleau (Wes)
1996-10-20 0:00 ` Robert A Duff
1996-10-21 0:00 ` Michael F Brenner
1996-10-21 0:00 ` Garbage collection (was a spinoff of a spinoff of a GA diatribe) Robert Dewar
1996-10-15 0:00 W. Wesley Groleau (Wes)
1996-10-16 0:00 ` Robert Dewar
1996-10-16 0:00 ` Jon S Anthony
1996-10-17 0:00 ` Robert Dewar
1996-10-18 0:00 ` Jon S Anthony
1996-10-23 0:00 ` Richard A. O'Keefe
1996-10-23 0:00 ` Mark A Biggar
1996-10-23 0:00 ` Larry Kilgallen
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox