From: Laurent.Guerby@enst-bretagne.fr (Laurent Guerby)
Subject: Re: Free'ing extended types
Date: 1996/04/29
Date: 1996-04-29T00:00:00+00:00 [thread overview]
Message-ID: <4xpw8qvlau.fsf@lagrange.enst-bretagne.fr> (raw)
In-Reply-To: dewar.830716817@schonberg
Jonas Nygren writes
[deleted complete Bob's crystal-clear explanations ;-]
: Yes, I think it would be nice. Every now and then I start thinking
: of defining my own language and implement it always with GC as a
: basic feature. But then it always stops at the thought because
: of the sheer complexity of the task.
[deleted]
Note that the impact of a GC on the "erronenousness" of a program
is interesting. An Ada run-time with GC can simply ignore
Unchecked_Dealocation calls, or do smart thing and raise Program_Error
when an access to a previously deallocated object is performed. In the
first case (do nothing on deallocation) I think the execution is not
erroneous because RM95-13.11.2(16) says :
"Evaluating a name that denotes a nonexistent object is erroneous.
The execution of a call to an instance of Unchecked_Deallocation is
erroneous if the object was created other than by an allocator for an
access type whose pool is Name'Storage_Pool."
On a garbage collected implementation, the object is likely to be
"existant" or your GC is wrong ;-).
: /jonas
--
-- Laurent Guerby, student at Telecom Bretagne (France), Team Ada.
-- "Use the Source, Luke. The Source will be with you, always (GPL)."
-- http://www-eleves.enst-bretagne.fr/~guerby/ (GATO Project).
-- Try GNAT, the GNU Ada 95 compiler (ftp://cs.nyu.edu/pub/gnat).
next prev parent reply other threads:[~1996-04-29 0:00 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-04-28 0:00 Free'ing extended types Jonas Nygren
1996-04-28 0:00 ` Robert Dewar
1996-04-29 0:00 ` Laurent Guerby [this message]
1996-04-29 0:00 ` Robert A Duff
1996-04-29 0:00 ` Robert Dewar
1996-04-29 0:00 ` Jonas Nygren
1996-04-29 0:00 ` Robert A Duff
1996-04-29 0:00 ` Robert Dewar
1996-04-29 0:00 ` Robert A Duff
1996-04-29 0:00 ` Jonas Nygren
1996-05-20 0:00 ` Type conversion between access types (was: Free'ing extended types) Scott Leschke
1996-05-21 0:00 ` Dale Stanbrough
1996-05-21 0:00 ` Robert A Duff
1996-05-21 0:00 ` Robert A Duff
1996-05-22 0:00 ` Scott Leschke
1996-05-23 0:00 ` Robert A Duff
1996-05-23 0:00 ` progers
1996-05-24 0:00 ` Scott Leschke
1996-05-24 0:00 ` Robert A Duff
1996-04-29 0:00 ` Free'ing extended types Laurent Guerby
1996-04-29 0:00 ` Robert A Duff
-- strict thread matches above, loose matches on Subject: below --
1996-04-26 0:00 Jonas Nygren
1996-04-26 0:00 ` Laurent Guerby
1996-04-27 0:00 ` Jerry van Dijk
1996-04-28 0:00 ` Robert Dewar
1996-04-28 0:00 ` Jonas Nygren
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