IEEE P1003.0 Draft 13 - September 1991 Copyright (c) 1991 by the Institute of Electrical and Electronics Engineers, Inc. 345 East 47th Street New York, NY 10017, USA All rights reserved as an unpublished work. This is an unapproved and unpublished IEEE Standards Draft, subject to change. The publication, distribution, or copying of this draft, as well as all derivative works based on this draft, is expressly prohibited except as set forth below. Permission is hereby granted for IEEE Standards Committee participants to reproduce this document for purposes of IEEE standardization activities only, and subject to the restrictions contained herein. Permission is hereby also granted for member bodies and technical committees of ISO and IEC to reproduce this document for purposes of developing a national position, subject to the restrictions contained herein. Permission is hereby also granted to the preceding entities to make limited copies of this document in an electronic form only for the stated activities. The following restrictions apply to reproducing or transmitting the document in any form: 1) all copies or portions thereof must identify the document's IEEE project number and draft number, and must be accompanied by this entire notice in a prominent location; 2) no portion of this document may be redistributed in any modified or abridged form without the prior approval of the IEEE Standards Department. Other entities seeking permission to reproduce this document, or any portion thereof, for standardization or other activities, must contact the IEEE Standards Department for the appropriate license. Use of information contained in this unapproved draft is at your own risk. IEEE Standards Department Copyright and Permissions 445 Hoes Lane, P.O. Box 1331 Piscataway, NJ 08855-1331, USA +1 (908) 562-3800 +1 (908) 562-1571 [FAX] P1003.0/D13 GUIDE TO THE POSIX OPEN SYSTEMS (1) There is minimum content. Specifically, a POSIX SP must reference some part of the suite of POSIX base standards. (Which part specifically is contentious.) (2) The POSIX SP must follow a specific approach to conformance (specifically the P1003.3.1 test methodology.) (3) The POSIX SP must adhere to the POSIX Reference Model. (4) There is maximum content; i.e., some consideration must be given to how the POSIX SP goes beyond the POSIX OSE as described in this guide. (5) Exceptions to the previous principles are expected, requiring a rule-making and enforcement body to make those exception decisions. POSIX SPs are Standardized Profiles that are related to ``POSIX.'' This subclause specifies the rules that need to be followed that distinguish POSIX SPs from ``Non-POSIX SPs''. Each POSIX SP is based on, and shall include, one of the following two base standards sets: (1) POSIX.1 {2} or POSIX.2 (as verified by the P1003.3 methodology), or (2) A particular subset of POSIX.1 {2} and P1003.4 that is being specified for a Minimal Realtime profile (as verified by the P1003.3 methodology.) Additionally, each POSIX SP adheres to the structure defined by the POSIX OSE reference model. An approved POSIX SP shall make reference only to base standards identified in this guide (1003.0) as being part of the POSIX OSE. Two specific exceptions to this general rule are allowed for as described here: (1) Reference can be made to required base standards that are clearly outside of the scope of the POSIX OSE. Examples of the functionality that may require the use of this expedient are: - Physical connectors - Electrical characteristics - Safety requirements Copyright c 1991 IEEE. All rights reserved. This is an unapproved IEEE Standards Draft, subject to change. 276 A Considerations for Developers of POSIX SPs ENVIRONMENT INTERIM DOCUMENT P1003.0/D13 Such reference to items outside the scope of the POSIX OSE shall be justified on a case-by-case basis. It shall be accompanied by details of the body responsible for the distribution and maintenance of the referenced base standard. (2) Reference can be made to required base standards that are being proposed for inclusion in a future version of the guide. Examples of this would be specification of a later version of a base standard that is already included within the POSIX OSE, or of an additional programming language base standard, not yet included within the POSIX OSE. In such cases, the POSIX SP should be identified as a POSIX Preliminary SP and the specific references should be clearly noted and justified on a case by case basis. A POSIX Preliminary Standardized Profile (POSIX Preliminary SP) is a POSIX SP that satisfies all requirements of a POSIX SP except that it is not a subset of the POSIX OSE. [It therefore contains at least one standard or profile that is outside the POSIX OSE. It is expected that application would be made to POSIX.0 to include the standard(s) or profile(s) in the POSIX OSE.] A further restriction of POSIX SPs is the necessity to (normatively) reference only standards that are recognized by the IEEE. This is limited to IEEE and ISO standards. Approval of a POSIX SP shall not change the status of any documents referenced by it. The development of a POSIX SP may indicate the need to modify or to add to the requirements specified in a base standard. In this case, it is necessary for the POSIX SP developer to liaise with the body responsible for that base standard so that the required changes may be made through established methods such as defect reporting, amendment procedures, or the introduction of new work. A.5 Other Issues A significant number of issues remain to be addressed concerning the management of POSIX SP development. Some of the issues and the concerns are summarized here. Copyright c 1991 IEEE. All rights reserved. This is an unapproved IEEE Standards Draft, subject to change. A.5 Other Issues 277 P1003.0/D13 GUIDE TO THE POSIX OPEN SYSTEMS Coherence The insurance of coherence among the many base standards referenced by a profile has been found by profile writers to be an onerous task. The profile writer's burden could be eased significantly if base standards writers address coherence at the outset. Specifically, all the P1003.x base standards should be developed to maximize their coherence. This is d seen as a management issue for TCOS-SEC, the sponsoring body of the d P1003.x standards. Conformance The development of conformance statements and test methods for profiles is a significant challenge for profile writers. The challenge is most acute in the area of conformance of standards that are being developed outside of P1003. A premise for the profile writing rules associated with conformance must be that the profile writers are not really experts in the referenced standards. Profile writers (especially at this early period in their development) must not be overburdened with untested conformance writing rules. A possible solution is to create a new project under the auspices of P1003.3 to actually generate new test methods and actually write the necessary assertions for the first profile. (This approach was used also for the initial POSIX base standard.) Base Standards Working Groups Because profile writers are in some sense the customers of base standards, it is important for base standards writers to address with priority and urgency the gaps identified in the development of POSIX SPs. Scope and Number of POSIX SPs How many different POSIX SPs are appropriate and how broadly ranging should be their scope? Should POSIX SPs be rather narrowly focused, spanning just a few base standards, or should they address a large number of base standards? Issues Pertaining to Referencing Base Standards Many practical writing issues pertain to referencing, for instance, parts of base standards. This includes not only referencing options, but even the concept of subsetting, or reducing the functionality of a base standard. Also an issue is how to reference multiple versions of the same standard (e.g., two different COBOL standards.) Copyright c 1991 IEEE. All rights reserved. This is an unapproved IEEE Standards Draft, subject to change. 278 A Considerations for Developers of POSIX SPs