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From: randhol+abuse@pvv.org (Preben Randhol)
Newsgroups: comp.lang.ada
Subject: Re: Question about Finalization Control and reference counting
Date: Wed, 25 Apr 2001 15:58:33 +0000 (UTC)
Organization: Norwegian university of science and technology
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Date: 2001-04-25T15:58:33+00:00
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On Tue, 24 Apr 2001 16:11:33 GMT, Jeffrey Carter wrote:
> Adjust only applies to a controlled type, so you need to put your access
> value inside a controlled type:
> 
> type Node;
> 
> type Node_Ptr is access all Node;
> 
> type Node is new [Limited_]Controlled with record
>    Prev  : Node_Ptr;
>    Data  : Whatever;
>    Count : Natural := 0;
>    Next  : Node_Ptr;
> end record;
> 
> procedure Adjust (Object : in out Node);
> 
> procedure Finalize (Object : in out Node);


But the problem is that if you have :

   Node1 : Node_Ptr;
   Node2 : Node_Ptr;
   Node3 : Node;

   ...

   After making the Nodes with new you:

   Node1.Next := Node2;

   Then Adjust of Node2 won't be called it will only be called if you
   do:

   Node3 := Node1.all;

   if I understand things correctly. I think I need to rethink my
   problem in a more Ada approach :-)


-- 
Preben Randhol ------------------- http://www.pvv.org/~randhol/ --
                 �For me, Ada95 puts back the joy in programming.�