[mod.std.unix] Draft ambiguity

std-unix@ut-sally.UUCP (Moderator, John Quarterman) (11/16/85)

Date:     Fri, 15 Nov 85 11:53:55 EST
From: Dan Franklin <dan@BBN-PROPHET.ARPA>

Some of the values in the column "Minimum value" are actually maximums rather
than minimums, and the draft should indicate this.  That is, for the minimums
CHAR_MIN, INT_MIN, LONG_MIN, and SHRT_MIN, the column gives the maximum
permissible value (as it should), not the minimum permissible.  Before I
realized this, I thought it was an error that the "minimum value" for CHAR_MIN
was 0 rather than -128.  One way to make this clearer would be to change the
column label "Minimum value" to "Minimum (Maximum) value" and put the values
which are actually "largest permissible minimums" rather than "smallest
permissible maximums" in parentheses.

	Dan

[ This comes up at every meeting.  Your method looks as good as any.  -mod ]

Volume-Number: Volume 3, Number 23

std-unix@ut-sally.UUCP (Moderator, John Quarterman) (11/20/85)

Date: Mon, 18 Nov 85 13:55:26 cst
From: ihnp4!uiucdcs!ccvaxa!preece@SEISMO.CSS.GOV (Scott Preece)

> [ This comes up at every meeting.  Your method looks as good as any.
> -mod ]
----------
Will there be a "Guide for voters" describing some of the things
that "come up at every meeting"?

[ There will be numerous and voluminous appendices, many of which
will serve that purpose (though they don't use that phrase :-).
This newsgroup also serves that purpose to some extent.  -mod ]

Volume-Number: Volume 3, Number 26

std-unix@ut-sally.UUCP (Moderator, John Quarterman) (11/20/85)

[ This is from a committee member who is more knowledgeable than I.
The usual disclaimers about not necessarily representing the official
position of IEEE, P1003, etc. apply.  -mod ]

From: athena!steved%tektronix.csnet@CSNET-RELAY.ARPA
Date: Tuesday, 19 Nov 85 10:27:06 PST

-----
John, 

In response to Dan Franklin's letter about changes in the standard concerning
the misleading (and sometimes contradictory) wording in the limits section.
In preparing draft 6, this section was cleaned up by the technical reviewers.

The body of the paragraph now says that the magnitude of the defined value 
must be greater than or equal to the magnitude of the value specified and
they must be of the same sign.  Also the column is simply labeled "Value".

This should clear up the ambiguity of the section.

On the question of these values being obtainable dynamically,  The intention
of this section is to present minimum magnitudes that the implementer can
be certain of having for a given implementation.  I.E. if the designer
makes sure that his application fits (so to speak) within these limits
it will work on any system.  I feel that the question of querying the values
at run time is really a different topic.  There really needs to be the two
classes of limits available. The limits file is not intended to represent
necessarily the current limit.  For example, PROC_MAX tells an application
programmer that he knows that there can be n processes existing simultaneously.
However, the o.s. implementer may have some dynamic allocation scheme where
the actual limit varies with say system load.  The goal of the standard is to
allow that kind of implementation.

The working committee will certainly accept and consider proposals for a 
routine that would provide the more esoteric program the ability to dynamically
determine what "current" limits are.  Clearly the case of the shell, wanting
to close all unused file descriptors is a good case for the routine.

Volume-Number: Volume 3, Number 30

std-unix@ut-sally.UUCP (Moderator, John Quarterman) (11/23/85)

Date: Fri, 22 Nov 85 09:34:32 cst
From: ihnp4!uiucdcs!ccvaxa!preece@SEISMO.CSS.GOV (Scott Preece)

> From: athena!steved%tektronix.csnet@CSNET-RELAY.ARPA
> The limits file is not intended to represent necessarily the current
> limit.  For example, PROC_MAX tells an application programmer that he
> knows that there can be n processes existing simultaneously.  However,
> the o.s. implementer may have some dynamic allocation scheme where the
> actual limit varies with say system load.  The goal of the standard is
> to allow that kind of implementation.
----------
There are a lot of error definitions in the draft that specifically
say that specific, named system limits have been exceeded.  For
instance, the fork error code mention PROC_MAX and CHILD_MAX.
If the limit is, in fact, dynamic or otherwise differs from the
named constant, you are causing confusion...

[ Yes, it's hard to find non-confusing language to describe this.  -mod ]

-- 
scott preece
gould/csd - urbana
ihnp4!uiucdcs!ccvaxa!preece

Volume-Number: Volume 3, Number 39

std-unix@ut-sally.UUCP (John Quarterman, Moderator) (11/26/85)

Date: Mon, 25 Nov 85 11:35:46 pst
From: saber!msc@ihnp4.uucp (Mark Callow)

>  [discussion by steved@athena and Scott Preece on limits.h, dynamic
>  limits and error message definitions in the draft (deleted for brevity)]
> 
> [ Yes, it's hard to find non-confusing language to describe this.  -mod ]
------------
"Non-confusing language" is only hard to find when the idea that you are
describing is confused.

[ Draft 6 is now available (see announcement in next article).
Suggest you look at the current wording in it, and propose new wording
which describes the appropriate ideas in non-confusing language.  -mod ]

Volume-Number: Volume 3, Number 42