This paper describes the design and implementation of an object-oriented Software Bus on top of DCOM, to be used as the core architecture of supervision systems. The approach is based on the design of abstract framewo...
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ISBN:
(纸本)0780351584
This paper describes the design and implementation of an object-oriented Software Bus on top of DCOM, to be used as the core architecture of supervision systems. The approach is based on the design of abstract frameworks that define the interactions between the system's objects. In order to fully leverage the modularity and openness offered by COM's interoperability, we propose to carefully design the object interfaces, using Framework and Design Patterns approaches. In addition, and despite the location transparency offered by ORE technologies, we relate how, in our experience, these frameworks must take into account the constraints of distributed systems (performances, reliability) in their design. We then describe the implementation of our system, how it exploits the COM technology, and how this latter matches the objectives that we had set for our system.
This paper advocates a strongly typed objectoriented system to shield the programmer from the complexities of availability and reliability. This system is based on attributes, typed objects, protocol composition and ...
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ISBN:
(纸本)0780399145
This paper advocates a strongly typed objectoriented system to shield the programmer from the complexities of availability and reliability. This system is based on attributes, typed objects, protocol composition and subtyping. The object type is encapsulated in every method invocation. This allows the system to intercept these invocations and invoke a meta-object that implement replication. The protocol composition property allows the construction of different protocol stacks based on the object attribute. The approach presented below does not make any assumptions regarding the language used by the programmer. A programmer for this system tags his object with the desired attributes to attain the required functionality. For example, a programmer wishing to replicate his object tags his object with the replica attribute and provides a nonreplicated implementation. Then it is the system, not the programmer that calls the replication meta-object. In short, there are no new application programmer interfaces (API) to learn for the programmer.
Since the coining of the term "Design Patterns" in the software engineering context, and specifically as related to object-oriented application, there has been an increasing emphasis placed on the relevance ...
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ISBN:
(纸本)0769500536
Since the coining of the term "Design Patterns" in the software engineering context, and specifically as related to object-oriented application, there has been an increasing emphasis placed on the relevance of patterns bt successfully designing object-oriented software, by the recognition of patterns that can be applied for recurring problems. In this paper patterns are applied in a business-oriented environment, resulting in a framework that provider the core architecture suitable for use across a family of business applications. III designing this framework we take a "framework-centred design pattern" approach [Pree95, p63], with a number of patterns being applied as the application framework evolver, The language In which our framework is implemented is Java.
A collection of algorithms and data structures are presented, which provide incremental dispatch table modification. Incrementally modified dispatch tables allow table-based dispatch techniques to be used in reflectiv...
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ISBN:
(纸本)081868383X
A collection of algorithms and data structures are presented, which provide incremental dispatch table modification. Incrementally modified dispatch tables allow table-based dispatch techniques to be used in reflective, dynamically typed, single-receiver languages with type/implementation-paired multiple inheritance. By storing a small amount of information, the algorithms can incrementally maintain the entire dispatch environment during the four fundamental environment modification requests: adding/removing selectors to/from classes and adding/removing class hierarchy links. The algorithms combine method dispatch calculation, inheritance management, and inheritance conflict detection into a single process, making tile algorithms highly efficient. The algorithms also incrementally compute hierarchy information to establish which method addresses can be uniquely identified during compilation.
This paper presents a technique, called interaction-orientedprogramming (IOP), which facilitates the design of large reactive systems. IOP is based on the assumption, that it is better to separate the coordination of...
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ISBN:
(纸本)0818687517
This paper presents a technique, called interaction-orientedprogramming (IOP), which facilitates the design of large reactive systems. IOP is based on the assumption, that it is better to separate the coordination of the components from the components itself making coordination patterns explicit. This contrasts with the usual practice, in which the coordination is directly handled inside the components. Apart from the basic technique some extensions are presented which enable restrictions on roles, time-constrained execution and localised code in order to specify more realistic coordination patterns.
Within the field of object-oriented type theory, much attention has been devoted to the notion of self and Self-types. In contrast, relatively little attention has been paid to this topic in studies on object-oriented...
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ISBN:
(纸本)0818684852
Within the field of object-oriented type theory, much attention has been devoted to the notion of self and Self-types. In contrast, relatively little attention has been paid to this topic in studies on object-oriented specification language semantics. In the context of language semantics, the notion of self poses two problems. Firstly, it involves an awareness by an object of its own identity, and hence a capacity for self-referential method invocations. Secondly, the usual reference model for object identity maps object identities to object values. This means that an object's identity is not normally considered to be a part of its value, and so a value for self is not normally in scope. The way that a semantics resolves the scope problem can affect one's ability to use the semantics to reason about an object independently of its environment. This paper motivates the inclusion of a concept of self in object-oriented formal specification languages, and shows how this concept can be accommodated within the semantics of object-Z. We show that a useful consequence of making objects 'self'-aware is that messages between objects can be 'tagged' with the identity of the sender object;this facilitates the task of reasoning about object interaction.
We have a few number of pilot projects in object-oriented Development (OOD) for small scale systems whose sizes are around 40 to 80 thousand fines of code in C++. We believe OOD should contribute in the software produ...
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ISBN:
(纸本)0818685859
We have a few number of pilot projects in object-oriented Development (OOD) for small scale systems whose sizes are around 40 to 80 thousand fines of code in C++. We believe OOD should contribute in the software productivity improvement. But we found some issues in OOD which should be more improved for industrial environment.
A number of essential issues in translating Smalltalk to Java are addressed. A convention is proposed for mapping Smalltalk method selectors to Java method names. In addition, a Java class hierarchy that parallels the...
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ISBN:
(纸本)3540643044
A number of essential issues in translating Smalltalk to Java are addressed. A convention is proposed for mapping Smalltalk method selectors to Java method names. In addition, a Java class hierarchy that parallels the Smalltalk class hierarchy (including the metaclass objects) is suggested These proposals are used to support ways of mapping both Smalltalk instance and class methods to their Java counterparts.
In languages like C++, the mechanism of protected members is critical to making inheritance work. It allows access to some of the internals of a base class B to the designer of a derived class D, while denying it to c...
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ISBN:
(纸本)081868383X
In languages like C++, the mechanism of protected members is critical to making inheritance work. It allows access to some of the internals of a base class B to the designer of a derived class D, while denying it to clients of B. We develop a formal approach in which class behavior is precisely specified in terms of an abstract specification and a concrete specification, the former for use by a client, the latter containing information about how the protected members change, for use by a derived class designer. We present rules that allow us to establish that a class meets both specifications.
Domain-specific generators will increasingly rely on graphical specification languages-applets-for declarative specifications of target applications. Applets will provide front-ends to generators and related tools to ...
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ISBN:
(纸本)0818683775
Domain-specific generators will increasingly rely on graphical specification languages-applets-for declarative specifications of target applications. Applets will provide front-ends to generators and related tools to produce customized code on demand. Critical to the success of this approach will be domain-specific design wizards, tools that guide users in their selection of components for constructing particular applications. In this paper;we present the P3 ContainerStore applet, its generator and design wizard.
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