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- Submitted-by: pc@hillside.co.uk (Peter Collinson)
-
- ENOBANDWDTH
- Stephe Walli
- USENIX Standards Report Editor
-
- [ENOBANDWDTH] - No Band Width Left An asynchronous signal was caught
- (such as SIGBALLOT, SIGPLSCOMMENT or SIGMORE2RD; See the description of
- <signal.h> in 3.3.1) while the programmer process was busy dealing
- with the last such signal. The current handler shall be interrupted
- after attempting to save context, and the new handler begins to
- execute. Signals shall continue to be delivered, interrupting one
- another, until {_POSIX_LAST_STRAW} is reached. (See description of
- Run- Time Randomly Varying Values in 2.8.4.1; Please note sysconf()
- always returns either a value of one greater than the true value at
- any particular time, or the return value from rand().) Once the true
- value of {_POSIX_LAST_STRAW} is reached, the entire precarious stack
- comes clattering down. The last interrupt handler with enough context
- to still maintain some semblance of integrity returns [ENOBANDWDTH].
- A programmer process may attempt to notify its parent process of the
- condition in an implementation defined way, but it shall be ignored.
-
- All joking aside, POSIX is finally beginning to strain the seams of
- the working groups, along with the standards process in which it lives.
-
- There was a time when POSIX meant a working group of around 20 people
- defining a system interface for source code portability, based on the
- C language interface to UNIX (356 pages). Then it started to grow.
-
- The shell and utilities were added (~ 900 + ~ 300 pages) making
- POSIX.2. Someone thought conformance testing should be done in a
- standard way, and since they started suspecting POSIX was going to
- grow some more, they decided to make a standard for defining test
- methods (47 pages). Then there were the test methods themselves.
- (Another 500 pages each for POSIX.1 and POSIX.2 so far.) Then came
- real-time, to take all the real-time sorts of things that POSIX.1
- couldn't settle on, along with a few things of interest only to the
- real-time community. (Another ~ 400 pages, plus threads.)
-
- You can continue in this vein for quite some time. The POSIX.20 (Ada
- Bindings for POSIX.4/.4a Real-time services) project has recently
- started up. This doesn't take into account the other related IEEE
- Technical Committee on Operating Systems standards (P1201 GUIs, P1224
- X.400, P1238 FTAM).
-
- The working groups NOW number between 350 and 400 people, who attend
- four one week long meetings a year. (As an aside, do the back of the
- envelope calculation as to the amount of money that represents. Using
- 350, $2000/week expenses, and a loaded staff cost of another
- $1500/week, I get $4,900,000/year.) The working groups generate a
- considerable quantity of reading material, documenting discussions and
- decisions, reviewing and co-ordinating with related efforts, proposing
- alternatives, and commenting on other proposals. This all on the way
- to producing the actual draft document to ballot as a standard.
-
- An average C programmer or applications designer would likely be
- interested in the base interfaces (POSIX.1), most of the real-time
- services (POSIX.4), some security (POSIX.6), and possible some of the
- networking (Transparent File Access - POSIX.8, and Protocol Independent
- Communications - POSIX.12). And of course the shell (POSIX.2/.2a).
- Whew! That's a lot of paper. POSIX Zen koan: Does a tree scream in
- the wilderness every time a new project request is approved?
-
- Before all the Ada and Fortran programmers start howling about the
- ``C'' programmer reference, let me explain. Until recently, the Ada or
- Fortran involvement in POSIX has been two small working groups who
- realised very early in the game that this standard was going to be
- extremely important. They have each now produced a standard binding of
- their respective languages to the C-based POSIX.1 standard.
-
- The Ada working group is now beginning to address POSIX.4 and
- POSIX.4a. The Fortran working group is beginning a Fortran 90 version
- of POSIX.1 (the original POSIX.9 standard being an F77 binding.) These
- groups are well placed to begin opening the way for a large segment of
- the systems building community that doesn't work in C to gain access
- to the benefits of a standard systems interface. They are, however,
- the exceptions to date, rather than the rule.
-
- With several vendors delivering POSIX.1 interfaces and POSIX.2 shells
- on their non-UNIX derived operating systems, the growth of interest in
- POSIX based open systems is only just beginning. This could bring in
- a badly needed injection of new blood to the POSIX working groups. BUT
- these people will not have the often needed historical context. They
- will require some time in the system to come up to speed on all of its
- perversities.
-
- Let's argue that you do care about all of these related base
- standards. (You should! They are being forced upon you in many
- cases.) That means you should be involved enough to at least ballot.
- Maybe not every section of every document, but certainly sections in
- each of these drafts. You cannot standby idly trusting that a good
- standard will fall out of the end of the process, and you can then use
- it. If you are a member of a technical user group such as USENIX, then
- the only difference between you and the people building the POSIX
- standards are that they've found the financial support of their
- organisations to attend the meetings. Think about it.
-
- If you cannot attend the meetings, then you should ballot the draft
- documents. (Ballot early! Ballot often!) But this then brings us back
- to [ENOBANDWDTH]. The balloting schedule for 1992 (as taken from a
- balloting status report of last December) looks something like the
- table.
-
- Project Ballot Date Size
- _______________________________________________________________
- POSIX.0 (Guide) 1st Ballot July 92 ~250 pgs
- POSIX.1a (More .1) 1st Ballot Summer 92 ~100 pgs
- POSIX.1/LIS 1st Ballot Spring 92 ~400 pgs
- POSIX.2a (UPE) 3rd Recirc Jan 92 ~300 pgs
- POSIX.3.2 (.2 Test methods) 1st Ballot Spring 92 ~500 pgs
- POSIX.4 (Real-time) 3rd Recirc Spring 92 ~320 pgs
- POSIX.4a (Threads) 1st Recirc Winter 92 ~200 pgs
- POSIX.4b (More Real-Time) 1st Ballot Fall 92 tbd
- POSIX.5 (Ada) Final Spring 92 ~300 pgs
- POSIX.10 (Super. AEP) 1st Ballot July 92 ~75 pgs
- POSIX.12 (Protocol Indep.) 1st Ballot Fall 92 ~400 pgs
- POSIX.13 (Real-time AEP) 1st Ballot Spring 92 ~80 pgs
- POSIX.15 (Batch) 1st Ballot July 92 ~175 pgs
- POSIX.16 (C Binding) 1st Ballot Spring 92 ~200 pgs
- POSIX.17 (Direct. Serv.) 1st Ballot Spring 92 tbd
- POSIX.18 (PEP) 1st Ballot Spring 92 tbd
-
- A few of these are a little bit specialized, such as POSIX.10
- (Supercomputing Profile), POSIX.13 (Real-time Profiles), POSIX.15
- (Supercomputing Batch Interfaces), and POSIX.17 (Directory Services).
- Note, however that these are the smaller documents. And I haven't
- mentioned the non- POSIX TCOS standards from P1201 (GUI), P1224
- (X.400), and P1238 (FTAM) that are also sending drafts to ballot in
- 1992.
-
- After a punishing year of balloting in 1991, the Ballotting Vice-Chair
- is staging the drafts so as to not completely bury the balloting
- groups in which there is often a lot of overlap. This means a working
- group had better hit its target date, or it will be left stuck
- circling the balloting schedule, looking for another time slot to hit.
-
- This heavy balloting load is starting to lead to the break down of the
- mock balloting process. In the ``good ol' days'' a document could be
- sent to mock ballot to test the waters, before committing to the
- serious work of a formal ballot. With so many documents out for
- formal ballot, most mock ballots are finding themselves at the bottom
- of the pile. [ENOBANDWDTH]
-
- The heavy balloting of large documents to large balloting groups is
- beginning to take its toll in other ways. The IEEE Standards Office
- can no longer absorb the entire cost of copying and distribution. For
- the first time in POSIX's history, the current invitation to ballot is
- charging a fee per document ($25) to join the group. [ENOFINANCES]?
-
- We've really only touched on the balloting load. If you are serious,
- and you find the financing, you can look forward to spending four
- weeks a year in exotic locations like Parsippany, New Jersey, at the
- working group meetings. If you stick strictly to a working group or
- two, you will actually be able to get out of the hotel for dinner.
- (Parsippany didn't have a lot to offer here, but then we have been to
- New Orleans.)
-
- If you are interested in any of the cross group issues, such as
- Language Independent Specifications, Conformance Testing, or most
- important of all, the overall structure of the POSIX standards, and
- the process of building it, you can look forward to six 12 to 13 hour
- days (not five).
-
- If you are a serious participant, i.e. you actually do work between
- meetings, you probably spend at least another week of your time on
- POSIX for every week of meeting time. Unless you are self-employed,
- it is unlikely you do this in plain sight at your place of business.
- It's generally frowned upon. After all, your manager already feels he's
- paying for you to attend four of these ``conferences'' a year.
- [ENOSUPPRT]?
-
- It is often surprising to discover how little corporate support exists
- for people in the process. There are many stories of people who cannot
- find the consistent support to participate, either moral or financial,
- who work for companies you would assume have an obvious stake in POSIX.
- While their companies love to bask in the glow of their ``obvious
- commitment to open systems'', their people are put through the wringer
- trying to get the job done right. (Please see the last line of the
- ENOBANDWDTH definition again.)
-
- So the coming year will be interesting. As many of the POSIX projects
- reach ballot, the number of documents circulating in ballot grows. The
- relentless and blind pressure from the market place to build more
- standards faster, will grow, rather than fade. The number of POSIX
- projects will continue to grow, before we've even figured out how the
- current ones integrate. Hark - I hear a tree screaming.
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- Volume-Number: Volume 27, Number 7
-
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