Abstract: A system and methodology providing service invocation for occasionally connected computing devices is described. In one embodiment, for example, in an occasionally connected computing environment, a system of the present invention for providing deferred invocation of services for a mobile device is described that comprises: an application running on a mobile device; a device-side object providing mobile support for a particular service from a server, the device-side object intercepting any requests from the application for invocation of the particular service, thereby deferring actual invocation of the particular service at that time; and a server-side object residing on the server that passes the requests on to a service provider for actual invocation while the mobile device is connected, and returns any result from the actual invocation back to the mobile device for use by the application.

Abstract: A method for implementing virtual method invocation when a compiled code of an invoked method is shared between class types that share a runtime representation is provided. In this method, an entry of an inline cache is set to a reference to an object. Subsequently, instructions for calling code are modified and the inline cache is set to be in one of an unresolved state, a monomorphic state, a shared monomorphic state, or a megamorphic state. A computer readable medium and a system for implementing virtual method invocation are also described.

Abstract: Asynchronous invocations are needed in the context of distributed object frameworks to prevent clients from blocking during remote invocations. Popular Web service frameworks offer only synchronous invocations (over HTTP). An alternative is messaging protocols but these implement a different communication paradigm. When client asynchrony is not supported, client developers have to build asynchronous invocations on top of the synchronous invocation facility. But this is tedious, error-prone, and might result in different remote invocation styles used within the same application. We present a number of patterns for asynchronous invocations and explain how these patterns can be used to build asynchronous invocation facilities for Web service frameworks. We exemplify this approach by explaining the design and implementation of an asynchronous invocation framework for Apache Axis.

Abstract: Summary form only given. Within the trend of object-based distributed computing, we present the design and implementation of a numerical simulation for electromagnetic waves propagation. A sequential Java design and implementation is first presented. Further, a distributed and parallel version is derived from the first, using an active object pattern. In addition, benchmarks are presented on this nonembarrassingly parallel application. A first contribution resides in the sequential object-oriented design that proved to be very modular and extensible; the classes and abstractions are designed to allow both element and volume type methods, furthermore, valid on structured, unstructured, or hybrid meshes. Compared to a Fortran version, the performance of this highly modular version proved to be in the same range. It is also shown how smoothly the sequential version can be distributed, keeping the same structuring and object abstractions, allowing to deal with larger data size. Finally, benchmarks on up to 64 processors compare the performances with respect to sequential and parallel versions, putting that in perspective with a comparable Fortran version.

Abstract: The present invention provides methods, systems and tools for analyzing a consistency and an inconsistency between a JSP page and a component related to the page, and verifying them automatically. In an example embodiment, the present invention includes a monitor for monitoring execution of a component invocation in a web page in which contents are generated dynamically, and extracting information on the component invocation; and a consistency verification unit for verifying the consistency between the component invocation and the component which is a target of it, based on the information on the component invocation extracted by the monitor.

Abstract: A technique for facilitating coordination of actions by multiple programs involves providing an execution environment for active objects. The execution environment may be an object space. Client programs may write active objects to the object space, which execute on behalf of the client programs. The client programs may obtain the results of the executed active objects, even if the client program is disconnected from the object space while the active object is executing.

Abstract: Publisher Summary This chapter describes the active container concept and its implementation in Java: JACOb. JACOb is the server-part of the Mandala project, which focuses on dynamic distribution of objects using the Java reflection facility. The chapter discusses the new paradigm for distributed programming: active containers. Problems related to remote objects are dealt in the chapter. Then JACOb, Java implementation of the concept is presented. There are many applications that can be developed in a straightforward manner using the framework of active containers. The chapter explains some of them that illustrate the ease of use of the concept and its capacity to model some interesting applications in the distributed world. Latency is defined by the delay between a method invocation and its effective execution. The latency introduced by the network on remote method invocation is several times the order of magnitude of the local method invocation's one. Remote objects must usually deal with concurrent method invocation and this prevents non thread-safe objects from becoming remote without care. As in the partial failure case, the concept does not specify the semantic of method invocation on the active container nor on its stored objects. The implementation is free to provide some mechanism that enable non thread-safe objects to be inserted into remote active container and thus to be accessed remotely.

Abstract: The invention refers to a method and system to search the object by use of area object net. The system includes a search position indicator, able to determine the position of object source by detecting a radio wave from the object source. The search position indicator is input with the object code of destination, receives many signals from object sources and selects the signal of appointed object, calculates the direction and distance of the appointed object, approaches the appointed object and adjusts the position in time, and finally find the appointed object. An object transmitting tower can lead users to find the destination covered by object transmitting tower by information transmission and screening with the search position indicator, and the net developed by many object transmitting towers can lead users to find all the objects covered by the net.

Abstract: In this paper we present a new infrastructure for building distributed applications that communicate through remote objects. The objects are available by the use of the Java RMI, enhanced by replication. Shared objects may be arbitrary complex with references to other objects allowing nested invocations. The replication process may be controlled and tuned by careful design of shared objects granularity, explicit synchronization operations, and replication domains definitions.

Abstract: Asynchronous invocations are needed in the context of distributed object frameworks to preve nt clients from blocking during remote invocations. Popular Web Service frameworks offer only synchronous invocations (over HTTP). An alternative are messaging protocols but these implement a different communication paradigm. When client asynchrony is not supported, client developers have to build asynchronous invocations on top of the synchronous invocation facility. But this is tedious, error-prone, and might result in different remote invocation styles used within the same application. We present a number of patterns for asynchronous invocations and explain how these patterns can be used to build asynchronous invocation facilities for Web Service frameworks. We exemplify this approach by explaining the design and implementation of an asynchronous invocation framework for Apache Axis.

Abstract: Java and distributed object models are important for building modern, scalable and interoperable applications. This paper is focused on the comparison and performance analysis of four important distributed object models for Java: RMI (Remote Method Invocation) and RMI-IIOP (Remote Method Invocation over Internet Inter-ORB Protocol), CORBA and DCOM. The paper presents a detailed performance analysis of the models and an overhead analysis to identify the bottlenecks in the models.

Abstract: Distributed Java applications use remote method invocation as a communication means between distributed objects. The ProActive library provides high level primitives and strong semantic guarantees for programming Java applications with distributed, mobile, secured components. We present a method for building finite, parameterized models capturing the behavioural semantics of ProActive objects. Our models are symbolic networks of labelled transition systems, whose labels represent (abstractions of) remote method calls. In contrast to the usual finite models, they encode naturally and finitely a large class of distributed object-oriented applications. Their finite instantiations can be used in classical model-checkers and equivalence-checkers for checking temporal logic properties in a compositional manner. We are building a software tool set for the analysis of ProActive applications using these methods.