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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Garbage collection (was a spinoff of a spinoff of a GA diatribe)
Date: 1996/10/16
Message-ID: <dewar.845471155@merv>#1/1
X-Deja-AN: 189823599
references: <9610152135.AA13753@most>
organization: New York University
newsgroups: comp.lang.ada
Date: 1996-10-16T00:00:00+00:00
List-Id: <comp.lang.ada>


Wes says

"And with composites, the provider of the data type has the complete freedom
of choice to extend a controlled type with GC, extend a controlled type
without GC, or not use a controlled type.

So, compared to the above, how big is the payoff of having GC imposed on
you by the implementation?"


I don't think it is quite that simple. There is nothing to prevent a
compiler having a temporary copy of a pointer to some controlled object
in a register if this would not normally be detectable by as-if semantics.
Perhaps one can do a simple collector, but certainly a compacting collector
raises question marks.

Even the simple collector is not so simple as far as we can tell. If someone
thinks it is trivial, and would like to contribute a garbage collected pool
that really works to the Ada community, that would be very welcome!