ANSI INCITS ISO IEC 10746-4-1998 Information technology - Open Distributed Processing - Reference Model Architectural semantics.pdf

1、B CReference numberISO/IEC 10746-4:1998(E)INTERNATIONALSTANDARDISO/IEC10746-4First edition1998-12-15Information technology Open DistributedProcessing Reference Model:Architectural semanticsTechnologies de linformation Traitement distribu ouvert Modle derfrence: Smantique architecturaleAdopted by INC

2、ITS (InterNational Committee for Information Technology Standards) as an American National Standard.Date of ANSI Approval: 11/27/2002Published by American National Standards Institute,25 West 43rd Street, New York, New York 10036Copyright 2002 by Information Technology Industry Council (ITI).All rig

3、hts reserved.These materials are subject to copyright claims of International Standardization Organization (ISO), InternationalElectrotechnical Commission (IEC), American National Standards Institute (ANSI), and Information Technology Industry Council(ITI). Not for resale. No part of this publicatio

4、n may be reproduced in any form, including an electronic retrieval system, withoutthe prior written permission of ITI. All requests pertaining to this standard should be submitted to ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaISO/IEC 10746-4:1998(E) ISO/IEC 1

5、998All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic ormechanical, including photocopying and microfilm, without permission in writing from the publisher.ISO/IEC Copyright Office Case postale 56 CH-1211

6、Genve 20 SwitzerlandPrinted in SwitzerlandiiContents Page1 Scope 12 Normative references . 23 Definitions 23.1 Definitions from ISO/IEC 8807 23.2 Definitions from ITU-T Recommendation Z.100. 23.3 Definitions from the Z-Base Standard 33.4 Definitions from ISO/IEC 9074 34 Interpretation of modelling c

7、oncepts . 34.1 Architectural semantics in LOTOS. 34.2 Architectural semantics in ACT ONE 94.3 Architectural semantics in SDL-92. 154.4 Architectural semantics in Z. 204.5 Architectural semantics in ESTELLE. 25 ISO/IEC ISO/IEC 10746-4:1998(E)iiiForewordISO (the International Organization for Standard

8、ization) and IEC (the International Electrotechnical Commission) formthe specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in thedevelopment of International Standards through technical committees established by the respective organization t

9、o dealwith particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest.Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in thework.In the field of information technology, ISO and I

10、EC have established a joint technical committee, ISO/IEC JTC 1. DraftInternational Standards adopted by the joint technical committee are circulated to national bodies for voting. Publicationas an International Standard requires approval by at least 75 % of the national bodies casting a vote.Interna

11、tional Standard ISO/IEC 10746-4 was prepared by Joint Technical Committee ISO/IEC JTC 1, Informationtechnology, Subcommittee SC 33, Distributed application services, in collaboration with ITU-T. The identical text ispublished as ITU-T Recommendation X.904.ISO/IEC 10746 consists of the following part

12、s, under the general title Information technology Open DistributedProcessing Reference Model: Part 1: Overview Part 2: Foundations Part 3: Architecture Part 4: Architectural semanticsivIntroductionThis Recommendation | International Standard is an integral part of the ODP Reference Model. It contain

13、s aformalisation of the ODP modeling concepts defined in ITU-T Rec. X.902 ISO/IEC 10746-2, clauses 8 and 9. Theformalisation is achieved by interpreting each concept in terms of the constructs of the different standardised formaldescription techniques.This Recommendation | International Standard is

14、accompanied by an amendment and a technical report. The associatedamendment focuses on the formalisation of the computational viewpoint language contained in ITU-T Rec. X.903 |ISO/IEC 10746-3. The associated technical report contains examples on how the formalisation of the ODP ReferenceModel can be

15、 applied to develop specifications. ISO/IECISO/IEC 10746-4:1998(E),62 ,( ( 1,17(51$7,21$/ 67$1$5ISO/IEC 10746-4 : 1998 (E)ITU-T Rec. X.904 (1997 E),78 7 5( HQDEOLQJ RSHUDWRU ( ) ; GLVDEOLQJ RSHUDWRU (); FKRLFH RSHUDWRU () RI EHKDYLRXUV The composition of the EHKDYLRXU HSUHVVLRQV associated with the

16、component objects inthe creation of a composite object through composition. The operators for the composition of behavioursare the same as those for the composition of objects.( 5HILQHPHQWRefinement is the process by which an object may be modified, either by extending or reducing its behaviour or a

17、combination of both, so that it conforms to another object. Letting 3 and 4 be LOTOS processes, an HWHQVLRQ of 3 by 4(written as 4 HWHQGV 3) means that 4 has no less traces than 3, but in an environment whose traces are limited to thoseof 3, then 4 has the same deadlocks. A UHGXFWLRQ of 3 by 4 (writ

18、ten as 4 UHGXFHV 3) means that 4 has no more tracesthan 3, but in an environment whose traces are limited to those of 4, then 3 has the same deadlocks.7UDFHA trace of the behaviour of an object from its initial instantiated state to some other state is a recording of the finitesequence of interactio

19、ns REVHUYDEOH HYHQWV between the object and its environment.7SH RI DQ ;!Types that can be written down explicitly in LOTOS for objects and interfaces are template types. There is no explicitconstruct in LOTOS that will permit the modeling of action types as such. A LOTOS specification consists of aE

20、HKDYLRXU HSUHVVLRQ which is itself composed of DFWLRQ GHQRWDWLRQV (action templates). These action templates eitheroccur as part of the behaviour of the system, in which case their occurrence may loosely be regarded as the actiontemplate instantiation, or they do not occur, in which case the action

21、template remains uninstantiated. The actiontemplates themselves may be given by the LQWHUQDO HYHQW symbol, L, or event offers at JDWHV which may or may not havefinite sequence of value and/or variable declarations.LOTOS does not offer facilities to characterise actions directly, however, a limited f

22、orm of action characterisation isbuilt into the VQFKURQLVDWLRQ feature of LOTOS. That is, it might be considered that synchronised DFWLRQ GHQRWDWLRQV(action templates) must satisfy the same action type in order for the action to occur. However, LOTOS does not classifythe characterising features of t

23、hese arbitrary DFWLRQ GHQRWDWLRQV and thus it is not possible to put a formal type to anygiven action. It might be the case that informally the event offers involved in an interaction are given a cause and effectrole, but this is generally not the case. See 4.1.1.8.The LQWHUQDO HYHQW symbol may be u

24、sed to represent an action type, where the common characteristics of this collectionof actions are that they have no characteristics.It should be noted that by stating that the only predicate possible in LOTOS for objects (and interfaces) are that theysatisfy their template type, the concepts of typ

25、e and template type as given in ITU-T Rec. X.902 | ISO/IEC 10746-2reduce to the same modeling technique in LOTOS. Thus there is no distinction in LOTOS between a type in its broadcharacterisation sense, and a template type in its more restrictive sense of template instantiation.!The notion of class

26、is dependent upon the characterising type predicate which the members of the class satisfy. Objects,interfaces and actions can satisfy many arbitrary characterising type predicates. A type that can be written down is atemplate type. When this is the case, the class of objects, interfaces and actions

27、 associated with that type is the templateclass.NOTE It should be noted that by stating that the only classification possible in LOTOS for objects, interfaces and actions is thatthey satisfy their template type, the concepts of class and template class as given in ITU-T Rec. X.902 | ISO/IEC 10746-2

28、reduceto the same modeling technique in LOTOS. Thus there is no distinction in LOTOS between a class in its general classificationsense, and a template class in its more restrictive sense as the set of instances of a given template type.6XEWSH 6XSHUWSHAs the types that can be written down in LOTOS f

29、or objects, interfaces and, to a lesser extent, actions, are templatetypes, a subtype relation in LOTOS is a relation that may exist between template types. In LOTOS, however, there existsno direct feature to write down subtyping relations directly. If subtyping is required then HWHQVLRQ can be used

30、 to give asubtype relation based on substitutability, however, this is not a feature explicitly provided for in LOTOS.6XEFODVV 6XSHUFODVVAs the types that can be written down in LOTOS for objects, interfaces and, to a lesser extent, actions, are templatetypes, a subclass relation exists between two

31、classes when a subtyping relation exists between their correspondingtemplate types.,62 ,( ( 7;! 7HPSODWH 2EMHFW 7HPSODWH A SURFHVV GHILQLWLRQ with some means by which it can be uniquely identified onceinstantiated. If no value parameter list is given, then object identification will not be possible

32、for morethan one object instantiated from the object template.With regard to combination of object templates in LOTOS there are no existing combination operatorsexcept for a limited form of scoping using the LOTOS “ZKHUH” term. ,QWHUIDFH 7HPSODWH Any behaviour obtained from a SURFHVV GHILQLWLRQ by c

33、onsidering only theinteractions at a subset of the JDWHV associated with the SURFHVV GHILQLWLRQ This subsetting of the JDWHV LVachieved by KLGLQJ the JDWHV not required for the interactions under consideration.With regard to combination of interface templates in LOTOS there are no existing combinati

34、on operatorsexcept for a limited form of scoping using the LOTOS “ZKHUH” term. $FWLRQ 7HPSODWH An DFWLRQ GHQRWDWLRQ where an DFWLRQ GHQRWDWLRQ may be either an LQWHUQDO HYHQWsymbol, a gate-identifier or a gate-identifier followed by a finite sequence of value and/or variabledeclarations.NOTE The def

35、inition here of DFWLRQ GHQRWDWLRQ is contrived as LOTOS does not really support the concept of an actiontemplate. In LOTOS, possible behaviours are specified by giving DFWLRQ GHQRWDWLRQV combined in some form. To relate a templateto an DFWLRQ GHQRWDWLRQ is the closest that can be achieved in LOTOS.

36、However, the text of ITU-T Rec. X.902 | ISO/IEC 10746-2requires an action template to group the characteristics of actions. This is not part of LOTOS as event offers DFWLRQ GHQRWDWLRQV exist in isolation and it is not possible to collect them and apply a template to characterise them.Composition of

37、action templates may loosely be likened to VQFKURQLVDWLRQ with value passing or value generation. In this case,two (or more) action templates agree on a common action template for the VQFKURQLVDWLRQ to occur, i.e. an action template withthe common characteristics of all of the action templates invol

38、ved in the VQFKURQLVDWLRQ (composition).,QWHUIDFH VLJQDWXUHAn interface signature as a set of action templates associated with the interactions of an interface is represented inLOTOS by a set of DFWLRQ GHQRWDWLRQV The members of this set are those DFWLRQ GHQRWDWLRQV that require VQFKURQLVDWLRQwith t

39、he environment in order to occur.,QVWDQWLDWLRQ RI DQ ; ! 7HPSODWH RI DQ 2EMHFW 7HPSODWH The result of a process which uses an object template to create a new object inits initial state. This process involves the DFWXDOLVDWLRQ of the IRUPDO JDWH OLVW and IRUPDO SDUDPHWHUV of aSURFHVV GHILQLWLRQ by a

40、one-one relabelling from a specified gate list and list of actual parameters. Thefeatures of the object created will be governed by the object template and any parameters used toinstantiate it. RI DQ ,QWHUIDFH 7HPSODWH The result of a process by which an interface is created from an interfacetemplat

41、e. The interface created can thereafter be used by the object it is associated with to interact withthe environment. The features of the interface created will be determined by the interface template andany parameters used to instantiate it. RI DQ $FWLRQ 7HPSODWH This is given as action occurrence i

42、n LOTOS. This may involve the rewriting ofACT ONE expressions.5ROHA name associated with a SURFHVV GHILQLWLRQ in the template for a composite object (i.e. LOTOS composition ofEHKDYLRXU HSUHVVLRQV As such, roles cannot be used as parameters. However, it is possible to assign data values toeach role i

43、n a composition in order to distinguish or address them specifically.! RI DQ REMHFW The instantiation of an object template as part of the behaviour of an existing object. RI DQ LQWHUIDFH As objects and interfaces are modelled the same way in LOTOS (via SURFHVV GHILQLWLRQV creation of objects corres

44、ponds to creation of interfaces. Thus the definition for interface creation is givenby the creation of objects.,QWURGXFWLRQ RI DQ REMHFW The LQVWDQWLDWLRQ of the behaviour associated with a LOTOS specification.,62 ,( ( HOHWLRQ RI DQ ; ! RI DQ REMHFW The termination of a process LQVWDQWLDWLRQ This ma

45、y be achieved through the use of theLOTOS GLVDEOLQJ RSHUDWRU the LOTOS inaction VWRS EHKDYLRXU HSUHVVLRQ which does not allow forthe passing of control, or the successful termination HLW EHKDYLRXU HSUHVVLRQ where passing of controlis possible via the HQDEOLQJ RSHUDWRU RI DQ LQWHUIDFH The process by

46、which the future behaviour of an object is limited to that behaviourwhich did not require the participation of the given interface to be deleted.,QVWDQFH RI D WSH RI DQ 2EMHFW 7HPSODWH An instance of a given object template is represented in LOTOS by aninstantiation of that object template or an acc

47、eptable substitution for an instantiation of that objecttemplate. Here the acceptable substitute should capture the characteristics that identify this type. Thus anacceptable substitute might be another template that is behaviourally compatible with the first. This mightbe achieved through HWHQVLRQ

48、as defined in section 4.1.2.4. Using this relation guarantees that allcharacteristics of the type under consideration are included. It might be the case, however, that a weakerform of type satisfaction relation can be found which does not require all characteristics associated with agiven template t

49、o be included, but some subset of the total characteristics. RI DQ ,QWHUIDFH 7HPSODWH As an interface template is represented the same way as an object template(via a SURFHVV GHILQLWLRQ in LOTOS), the above text applies equally well (i.e. replace all occurrences ofobject with interface) for instance of an interface template. RI DQ $FWLRQ 7HPSODWH An instance of an action template DFWLRQ GHQRWDWLRQ is represented in LOTOSby another DFWLRQ GHQRWDWLRQ offering an equivalent event offer.7HPSODWH