Re: ISO/IEC 14519 - Ada POSIX binding

["Warren W. Gay VE3WWG" <ve3wwg@cogeco.ca>]

Mark Lorenzen wrote:
> Florian Weimer <fw@deneb.enyo.de> writes:
>>Mark Lorenzen <mark.lorenzen@ofir.dk> writes:
>>
>>>So my big question is therefore: What's wrong with ISO/IEC 14519? It
>>>is of course pretty big, but that is a natural consequence of POSIX
>>>being big.
>>
>>There is no affordable documentation, for a start.  POSIX.5 itself is
>>rather expensive.  There is no publicly accessible implementation.  As
>>a result, hardly anybody knows how the interface "feels" in practice.
>>
>>The rest of POSIX.5 has severe design deficiencies; I think it's
>>reasonable to assume that binding to the BSD sockets API is not much
>>better.
> 
> (Sorry if this is sent twice)
> 
> Personally I do not think that 44 CFH (approx. 33 USD) is expensive:
> 
> http://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=34354&ICS1=35&ICS2=60&ICS3=

Many feel that a standard should be freely available. In this case,
I would agree.  It certainly helps to gain better acceptance.

> And we have a publicly available implementation called 'florist':
> 
> http://libre.act-europe.fr/GNAT/

Ahem, FLORIST is :

  1. only available to GNAT users

  2. portable only to UNIX like systems so far

  3. incomplete (no UNIX/Local socket support yet etc.)

  4. and subject to platform differences (errno EAGAIN vs EWOULDBLOCK
     differences etc.)

> You are correct that POSIX is not perfect, but it is PORTABLE and

Not completely, without planning for the platforms that it is to
compile on. I doubt that FLORIST guarantees uniform errno reporting,
so you end up having to know which platform you are on (or in some
simpler cases, planning for EAGAIN/EWOULDBLOCK as equally likely --
though not all situations are this simple).

> supported by a lot of interesting platforms. If we want to persuade
> people to using Ada instead of the "usual" languages for anything else
> than real-time or embedded systems, then we NEED support for POSIX.

I am not against POSIX support. I welcome FLORIST improvements (I
use it actively). But to tie another Ada standard package to POSIX
directly is unwise.

> At the company where I work, we have just finished a proposal for a
> system that initially must run on Solaris and must then later be
> ported to Linux. What is the key here? POSIX! The system consists of
> several UNIX processes and makes use of networking sockets, message
> queues, real-time signals, memory mapping and memory locking (but not
> shared memory). While POSIX may not be perfekt it is what is used in
> the "real" world.

Well, when you go to run that under Open/Net/FreeBSD, get ready to
make some adjustments. There is a world of difference between Linux
and FreeBSD on some of the APIs. ;-)

-- 
Warren W. Gay VE3WWG
http://home.cogeco.ca/~ve3wwg