home *** CD-ROM | disk | FTP | other *** search
- From: mcvax!sphinx.co.uk!domo@seismo.UUCP (Dominic Dunlop)
-
- Nice to see SAS on the net -- although your sales people play coy about if
- and when a UNIX implementation might see the light of day (no, I'm not
- asking you to comment...)
-
- In article <166@sas.UUCP> you write:
- >Is there any effort in the standards efforts to provide kernel (or CRT lib.)
- >support for this [dynamic loading/execution from data space]?
-
- No. To my knowledge it hasn't come up at all on POSIX (although I didn't
- attend last week's meeting in Seattle). Not least of the problems is that
-
- 1. The classic BSD implemenataion depends on a highly machine-dependent
- aspect of VAX memory management.
-
- 2. Quite a few people (and I'd probably number myself among them)
- consider this aspect of VAX memory management to be brain-damaged, or
- at least to be something which could be done better by throwing a few
- more gates at the problem (gates weren't so cheap or fast in 1978).
-
- 3. Later memory management implementations may well specifically
- exclude ``doing things the VAX way'' because it is judged to be
- unclean and/or unsafe. Certainly, many 68x00 implementations don't
- allow execution out of data space, and don't provide a kernel call
- which (in effect) allows programs to move the boundary between text
- and data.
-
- Consequently, any attempt to introduce the topic to POSIX would be
- controversial, and POSIX does not need controversy if a standard is to be
- ratified on schedule!
-
- To put it another way, this is a political issue... However, if you were
- to make a more or less formal proposal by mailing John Quarterman,
- moderator of comp.std.unix (std-unix@ut-sally) you could flag a valid
- technical issue as open, and might even get a formal reply from the working
- group.
-
- If you want to rope in somebody with heavy-duty experience of this issue,
- Catalytix Corp. of Cambridge MA (phone 617 429 2160 -- I don't have a net
- address) have had to fight it in bringing up their Safe-C interpreter in
- a variety of UN*X and other environments. (Safe-C is worth checking out
- if you're a developer, anyway.)
-
- The usual disclaimer: I don't speak for IEEE working group 1003.1 -- almost
- nobody can (in fact, the IEEE carries professional liability insurance
- just in case anybody wants to brief their lawyer to argue about it). These
- opinions are strictly my own.
-
- [ The quickest way to make a proposal to IEEE P1003.1 (the POSIX committee)
- is to mail a paper copy to
-
- Secretary, IEEE Standards Board
- Attention: P1003 Working Group
- 345 East 47th St.
- New York, NY 10017
-
- Formal notes to the committee have to go there, anyway, or be carried to
- a Working Group meeting. Feel free to submit a copy to comp.std.unix
- if you want to.
-
- As decided at the Seattle meeting (22-26 June 1987),
- all proposed changes to the P1003.1 draft standard must be
- in the form of balloting objections, i.e., actual proposed
- wording for the standard with attached rationale is required.
-
- You can still send in general comments, though. Also, your note
- might get redirected to another subcommittee which is more
- directly addressing related issues. Offhand, I don't know
- which one that might be: perhaps one of the /usr/group
- Technical Committees.
-
- I play several roles related to POSIX, and they frequently get confused:
- a) Moderator of comp.std.unix.
- b) Institutional Representative from USENIX to IEEE P1003.
- c) Member of the USENIX Board of Directors.
- d) Private contractor for the P1003.1 Rationale, funded by /usr/group.
-
- a) is largely a result of b), and c) is useful in doing b).
- d) is completely unrelated to the other three, and is finished.
-
- I can and sometimes do submit notes to P1003 as the USENIX
- Institutional Representative (e.g., the tar vs. cpio note).
- It's one of my functions in that role to gather information
- from the USENIX membership and the public and also to distribute
- information about POSIX and other standards. So, I could submit
- a note for you. It will just get there faster if you do it yourself....
-
- Dominic's disclaimer about speaking for IEEE or P1003 also
- applies to me, of course.
-
- -mod ]
-
- Dominic Dunlop, Sphinx Ltd. UKnet: domo@sphinx.co.uk
-
- Volume-Number: Volume 11, Number 87
-
-