SIZE RfD: Re: Extendable structure with inspection

From	anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups	comp.lang.forth
Subject	SIZE RfD: Re: Extendable structure with inspection
Date	2015-06-09 07:56 +0000
Organization	Institut fuer Computersprachen, Technische Universitaet Wien
Message-ID	<2015Jun9.095600@mips.complang.tuwien.ac.at> (permalink)
References	(2 earlier) <3eeb9c20-5898-48cf-9979-400ee121b5d4@googlegroups.com> <8021c02c-0a0c-42ef-bc8f-1635f64ae841@googlegroups.com> <5572d1d1$0$21304$e4fe514c@dreader37.news.xs4all.nl> <2015Jun6.180030@mips.complang.tuwien.ac.at> <ml513j$3ec$1@dont-email.me>

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Bernd Paysan <bernd.paysan@gmx.de> writes:
>Anton Ertl wrote:
>> Why would it be different?  If you and Hugh cannot agree on a name
>> (and probably not on a common specification, either), that's certainly
>> not the fault of the standardization process; on the contrary, it
>> would explain why there is no progress in standardizing this feature.
>
>One of the problem of the SIZE proposal is that it's not well specified, 
>which size.  Aparently, Hugh just wants to know how much memory the 
>allocater actually used, to allow cloning of lists without knowing what kind 
>of data is inside the list.  The other possible reason is to get what was 
>actually allocated, which can be used to allocate strings and query the 
>string length.  The second usage is not possible if you just return the size 
>of the actual memory chunk, but it's more useful.

The first usage would be useful for a region allocator.

The rationale for this thing is that the information is present anyway
(for FREE), and this holds only for the first usage.

>A memory allocater which works like the one of GLIBC could as well store the 
>actual size, and not the padded one, as doing the padding is a simple 
>operation, and it's not really harmful to do that on free() as well.

Ok, but we don't want to restrict the allocator to have this property,
do we?  E.g., it would rule out buddy allocators.  If we did, we could
just have two words: One for the requested size, and one for the
actual size.

- anton
-- 
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
     New standard: http://www.forth200x.org/forth200x.html
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Thread

Extendable structure with inspection humptydumpty <ouatubi@gmail.com> - 2015-06-02 13:29 -0700
  Re: Extendable structure with inspection anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-06-03 06:02 +0000
    Re: Extendable structure with inspection humptydumpty <ouatubi@gmail.com> - 2015-06-03 08:27 -0700
  Re: Extendable structure with inspection humptydumpty <ouatubi@gmail.com> - 2015-06-03 11:30 -0700
    Re: Extendable structure with inspection Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-06-03 20:54 -0700
      Re: Extendable structure with inspection "Alex McDonald" <blog@rivadpm.com> - 2015-06-04 09:11 +0100
        Re: Extendable structure with inspection Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-06-04 04:43 -0700
          Re: Extendable structure with inspection "Alex McDonald" <blog@rivadpm.com> - 2015-06-04 20:21 +0100
            Re: Extendable structure with inspection Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-06-04 23:23 -0700
              Re: Extendable structure with inspection "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-06-05 03:40 -0400
              Re: Extendable structure with inspection "Alex McDonald" <blog@rivadpm.com> - 2015-06-05 15:31 +0100
                Re: Extendable structure with inspection Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-06-05 08:48 -0700
                Re: Extendable structure with inspection "Alex McDonald" <blog@rivadpm.com> - 2015-06-05 18:10 +0100
                Re: Extendable structure with inspection albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-06-06 10:46 +0000
                Re: Extendable structure with inspection hughaguilar96@gmail.com - 2015-06-05 17:53 -0700
                Re: Extendable structure with inspection albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-06-06 10:56 +0000
                Re: Extendable structure with inspection anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-06-06 16:00 +0000
                Re: Extendable structure with inspection hughaguilar96@gmail.com - 2015-06-06 19:35 -0700
                Re: Extendable structure with inspection "Alex McDonald" <blog@rivadpm.com> - 2015-06-07 10:51 +0100
                Re: Extendable structure with inspection Bernd Paysan <bernd.paysan@gmx.de> - 2015-06-08 23:24 +0200
                SIZE RfD: Re: Extendable structure with inspection anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-06-09 07:56 +0000
                Re: Extendable structure with inspection "Alex McDonald" <blog@rivadpm.com> - 2015-06-09 12:09 +0100
                Re: Extendable structure with inspection Bernd Paysan <bernd.paysan@gmx.de> - 2015-06-09 23:25 +0200
              Re: Extendable structure with inspection "Elizabeth D. Rather" <erather@forth.com> - 2015-06-05 07:53 -1000
                Re: Extendable structure with inspection hughaguilar96@gmail.com - 2015-06-05 17:34 -0700
      Re: Extendable structure with inspection humptydumpty <ouatubi@gmail.com> - 2015-06-05 00:40 -0700
  Re: Extendable structure with inspection humptydumpty <ouatubi@gmail.com> - 2015-06-10 12:16 -0700

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