Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming. PhD thesis, The University of Tokyo, Japan, June 1993.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....In addition, CYES C supports many mechanisms to allow changes in the interaction behavior of methods. We give an example that illustrates the way in which the state partitioning anomaly can be resolved. The state partitioning anomaly occurs in the behavioral abstractionbased languages [12, 23, 14] when additions or modifications of methods in a subclass partition the states of objects of a superclass. Since the implementation of a method includes the state transitions that an object makes after the execution of the method, changes in the states (due to the state partitioning) therefore ....

....primitives such as locks and semaphores [4, 2] write once read manyvariables [5] and data flow based data dependencies [8] for specifying interaction among methods. ii) Languages such as enable based approaches [17, 22] disable based approaches [6] and behavior abstraction based approaches [12, 23, 14] that use boolean conditions to determine if a method should be executed or delayed. iii) Approaches that use regular expression [3] and temporal logic expressions for specifying interaction. Many of the interaction specification mechanisms do not allow one to define abstractions of interaction ....

Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming. PhD thesis, The University of Tokyo, Japan, June 1993.

....In addition, CYES C supports many mechanisms to allow changes in the interaction behavior of methods. We give an example that illustrates the way in which the state partitioning anomaly can be resolved. The state partitioning anomaly occurs in the behavioral abstraction based languages [4, 14, 6] when additions or modifications of methods in a subclass partition the states of objects of a superclass. Example 0.3. State partitioning) Let queueone be a subclass of queue. It defines a method gettwo. Method gettwo accesses two elements of the queue object atomically. Invocations of gettwo ....

Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming. PhD thesis, The University of Tokyo, Japan, June 1993.

....of object orientation: encapsulation, re use and modularity. This interference is particularly noticeable with regard to re use, where conflict between concurrency and re use by inheritance led to the definition of the inheritance anomaly [Mat90] and subsequent investigation of its nature [Mat93, Ber94, McH94]. Many early concurrent object oriented languages introduced concurrency and synchronisation without concern for their interaction with inheritance, nor for issues of flexibility and re use. As problems with inheritance were uncovered and re use became more important, various attempts were made ....

Matsuoka S., "Language Features for Re-use and Extensibility in Concurrent Object Oriented Programming Languages", Ph.D. dissertation, Dept. of Information Science, University of Tokyo, Japan, 1993

....concurrent interactions, so problems with reuse began to surface. Eventually these reuse issues were studied in more detail and the term inheritance anomaly was coined to describe them [Mat90] Since then nearly all new language proposals have been promoted as solving the inheritance anomaly [Baq95, Ber94, Fer95, Fro92, Lop94, Mat93, McH94, Mit95]; but while they might have avoided one or more of the problems categorised by Matsuoka, they didn t really address all of the issues of reuse. In some cases the quest for reuse seems to have been abandoned altogether, instead focussing on making it easier to use synchronisation in the first place ....

....all of the issues of reuse. In some cases the quest for reuse seems to have been abandoned altogether, instead focussing on making it easier to use synchronisation in the first place [Lop97] 2.4. 1 What is an Inheritance Anomaly The inheritance anomaly has been studied by many researchers [Mat93, McH94, Ber94] and many language proposals have been made to avoid the problem. Despite such research there is no commonly accepted cause of the problem. Some say the problem is synchronisation and the 43 mechanisms used to provide it [Mat93] America [Ame87] considered the problem to be that inheritance does ....

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Matsuoka S., "Language Features for Re-use and Extensibility in Concurrent ObjectOriented Programming Languages", Ph.D. Dissertation, Department of Information Science, University of Tokyo, Japan, 1993

....concurrent interactions, so problems with reuse began to surface. Eventually these reuse issues were studied in more detail and the term inheritance anomaly was coined to describe them [Mat90] Since then nearly all new language proposals have been promoted as solving the inheritance anomaly [Baq95, Ber94, Fer95, Fro92, Lop94, Mat93, McH94, Mit95]; but while they might have avoided one or more of the problems categorised by Matsuoka, they didn t really address all of the issues of reuse. In some cases the quest for reuse seems to have been abandoned altogether, instead focussing on making it easier to use synchronisation in the first place ....

....all of the issues of reuse. In some cases the quest for reuse seems to have been abandoned altogether, instead focussing on making it easier to use synchronisation in the first place [Lop97] 2.4. 1 What is an Inheritance Anomaly The inheritance anomaly has been studied by many researchers [Mat93, McH94, Ber94] and many language proposals have been made to avoid the problem. Despite such research there is no commonly accepted cause of the problem. Some say the problem is synchronisation and the 43 mechanisms used to provide it [Mat93] America [Ame87] considered the problem to be that inheritance does ....

[Article contains additional citation context not shown here]

Matsuoka S., "Language Features for Re-use and Extensibility in Concurrent ObjectOriented Programming Languages", Ph.D. Dissertation, Department of Information Science, University of Tokyo, Japan, 1993

....concurrent interactions, so problems with reuse began to surface. Eventually these reuse issues were studied in more detail and the term inheritance anomaly was coined to describe them [Mat90] Since then nearly all new language proposals have been promoted as solving the inheritance anomaly [Baq95, Ber94, Fer95, Fro92, Lop94, Mat93, McH94, Mit95]; but while they might have avoided one or more of the problems categorised by Matsuoka, they didn t really address all of the issues of reuse. In some cases the quest for reuse seems to have been abandoned altogether [Lop97] While the academic world developed the 98 (and more) concurrent ....

....is used. This is important to keep in mind as some solutions to server side anomalies simply transform the problem into a client side anomaly. Although occurrences of the inheritance anomaly are dependent both upon the language in use and the synchronisation being attempted, Matsuoka [Mat93] defined four main forms the anomaly can take. We will look at each of these forms in the broader context of seeing how anomalies can occur with regard to each aspect of synchronisation, why these occur and how they can in general be avoided. 4.1 Exclusion There are many different ways in which ....

Matsuoka S., "Language Features for reuse and Extensibility in Concurrent Object Oriented Programming Languages", Ph.D. Dissertation, Department of Information Science, University of Tokyo, Japan, 1993

....of the language, called ABCL 1, like the underlying actor model, did not support any form of inheritance, and is therefore an objectbased language. However, when adding inheritance to the language, the concept of inheritance anomaly is introduced into object oriented concurrent programming, [97, 98, 99, 100]. Inheritance anomaly is classified into three major categories: 1) Partioning of acceptable states (State Partitioning Anomaly) 2) History only sensitiveness of acceptable states (History only Sensitiveness Anomaly) and (3) Modification of acceptable states (State Modification Anomaly) It was ....

....such that they can be inherited, overridden, or extended separately without affecting each other. Furthermore, one scheme can be integrated and composed with other schemes. These standard protocols are provided to support synchronization schemes for resolving the inheritance anomaly [97, 98, 99, 100]. In AKL , each method is executed in the context of a class, called base class . This class may not be the class where the method is defined. The current contextual class is used to determine dynamically which methods are called. Within a method, the base class is referred to by the reserved ....

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Matsuoka S., Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming Languages, Ph. D. thesis, Department of Information Science, the University of Tokyo, 1993.

....the optimisation of synchronisation code. Analysis of the problems with the use of inheritance in COOPLs. A common belief is that there is a conflict between synchronisation and inheritance that can hinder the reuse of code [TS89] KL89] Neu91] GW91] Tho94] Loh93] BBI ] Mes93] BFS93] Mat93] Cou94] Ber94] We show that this perception of the conflict is incorrect; rather, the problem is rooted in the conflicting interaction of two different uses of inheritance. We survey the conflict in a variety of inheritance mechanisms and show that the use of generic synchronisation policies ....

....policies that can be expressed. We also show that GSPs facilitate the optimisation of synchronisation code. 2. 4 Analysis of the Problems with Inheritance in COOPLs It is well known that there are problems with the use of inheritance in COOPLs that can hinder code reuse [TS89] KL89] Mat93] Ber94] These problems are commonly referred to in the literature as inheritance anomalies. This section gives an intuitive explanation of a subset of the problems (a more detailed analysis can be found in Part IV of this thesis) Then in Section 2.4.1 we state the contributions that this ....

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Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-oriented Programming Languages. PhD thesis, Department of Information Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan, April 1993.

....to describe the process graph of an application. The compiler can use these informations to calculate a good mapping. This paradigm is not very easy to use and can be implemented with macroparallelism easily. 4. 4 Reflection A very promising approach to controlling parallelism is reflection [14, 13]. Reflection means that a program can reason about and change its own behavior on a meta level. By this many informations for parallelization usually given in a program can be provided on a meta level and hence the informations about how can be parallelized can be separated from the informations ....

Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming Languages. Doktorarbeit, Department of Information Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan, April 1993.

.... is given in [19] Examples of synchronization mechanisms are: semaphores [5, 3] write once read many variables [6] data flow based data dependencies [13] signal variables, enable based approaches [11, 18, 25, 17, 7, 12] disable based approaches [9] and behavior abstraction based approaches [14, 15]. Our proposed interaction specification mechanism differs from most approaches in that it is declarative, and compositional. It supports abstractions for defining interaction behaviors. The abstractions can be modified and extended in isolation from other abstractions. Further, they can composed ....

Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming. PhD thesis, The University of Tokyo, Japan, June 1993.

....the inheritance chain, thus avoiding the inheritance anomaly. Financed by JNICT grant BM92 3556 IA. y Part of this work was supported by JNICT PMCT 163 90. 1 Introduction In the past, several approaches to concurrent object oriented programming (COOP) raised the inheritance anomaly [10, 8], which restricts reuse by inheritance in the presence of synchronization code. Initial proposals to COOP were in fact largely exposed to this anomaly [6, 16, 1, 3] Partial solutions to this problem were sought through (a) the separation of synchronization code and its reuse by inheritance [12, ....

.... synchronization code and its reuse by inheritance [12, 15, 10] and (b) the first classing of synchronization code elements [5, 11] Recently the use of multiple synchronization schemes in the same language was advocated, allowing the programmer to choose the most appropriate scheme for each case [9, 8]. CA C follows these ideas and provides two distinct synchronization mechanisms, thereby regulating both internal and external concurrency. In CA C method invocations on any object can be specified on the client code as synchronous or asynchronous. In synchronous calls the client thread ....

[Article contains additional citation context not shown here]

Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming. PhD thesis, Department of Information Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan, April 1993. Thesis draft.

....enable a thread to animate the method code. Flags and method predicates are independently redefinable along the inheritance chain, thus avoiding the inheritance anomaly. 1 Introduction In the past, several approaches to concurrent object oriented programming (COOP) raised the inheritance anomaly [10, 8], which restricts reuse by inheritance in the presence of synchronization code. Initial proposals to COOP were in fact largely exposed to this anomaly [6, 16, 1, 3] Partial solutions to this problem were sought through (a) the separation of synchronization code and its reuse by inheritance [12, ....

.... synchronization code and its reuse by inheritance [12, 15, 10] and (b) the first classing of synchronization code elements [5, 11] Recently the use of multiple synchronization schemes in the same language was advocated, allowing the programmer to choose the most appropriate scheme for each case [9, 8]. CA C follows these ideas and provides two distinct synchronization mechanisms, thereby regulating both internal and external concurrency. In CA C method invocations on any object can be specified on the client code as synchronous or asynchronous. In synchronous calls the client thread ....

[Article contains additional citation context not shown here]

Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming. PhD thesis, Department of Information Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan, April 1993. Thesis draft.

....the subclasses. It is also straightforward to refine the locks by constructing a hierarchy of locks. Although it is possible to define write lock using either synchronizers or transition specifications, we only present the definition with the latter for brevity. Interested readers are referred to [14] for full details. Solution with Transition Specifications: class write lock methodsets: mset LOCKED # unlock redefined in subclass mset WRITE LOCKED self LOCKED; mset UNLOCKED all except(LOCKED) methods: Locking can be handled entirely with transitions. transitions ....

....with special purpose procedures for each method set, B) augmenting the scheduling of active objects in ABCL onAP1000, and (C) incorporating a new run time structure called a transition stack. Due to space limitations, we cannot present the technical details interested readers are referred to [28, 14]. In order to demonstrate the involved cost, we give the results of the preliminary benchmarks on intra node asynchronous message passings to the b buf objects described in Section 4 on AP1000 in Table 1, and also compare the result with that of the original ABCL onAP1000. A local put get message ....

Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming. PhD thesis, the University of Tokyo, Tokyo, Japan, June 1993.

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Satoshi Matsuoka. Language Features for Re-use and Extensibility in Concurrent Object-Oriented Programming. PhD thesis, The University of Tokyo, Japan, June 1993.

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Satoshi Matsuoka, Language Features for Re-use and Extensibility in Concurrent ObjectOriented Programming, Ph.D. thesis, The University of Tokyo, Japan (June 1993).

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