Summary form only given. Conforming to the underlying memory consistency rules is a fundamental requirement for implementing shared memory systems and developing multiprocessor programs. In order to promote understand...
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Summary form only given. Conforming to the underlying memory consistency rules is a fundamental requirement for implementing shared memory systems and developing multiprocessor programs. In order to promote understanding and enable automated verification, it is highly desirable that a memory model specification be both declarative and executable. We present a specification framework called Nemos (Nonoperational yet Executable Memory Ordering Specifications), which supports precise specification and automatic execution in the same framework. We employ a uniform notation based on predicate logic to define shared memory semantics in an axiomatic as well as compositional style. We also apply constraint logicprogramming and SAT solving to make the axiomatic specifications executable for memory model analysis. To illustrate our approach, we formalize a collection of classical memory models, including sequential consistency, coherence, PRAM, causal consistency, and processor consistency.
Summary form only given. We address programming abstractions for building protocols from smaller, reusable microprotocols. the existing protocol frameworks, such as Appia and Cactus, either restrict the amount of conc...
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Summary form only given. We address programming abstractions for building protocols from smaller, reusable microprotocols. the existing protocol frameworks, such as Appia and Cactus, either restrict the amount of concurrency between microprotocols, or depend on the programmer, who should implement all the necessary synchronisation using standard language facilities. We develop J-SAMOA: a framework for a synchronisation augmented microprotocol approach in Java. It has been designed to allow concurrent protocols to be expressed without explicit low-level synchronisation, thus making programming easier and less error-prone. We describe versioning concurrency control algorithms. they are used by the runtime system of our framework to guarantee that the concurrent execution of a protocol is equivalent to a serial execution of its microprotocols. this guarantee, called the isolation property, ensures consistency of session or message-specific data maintained by microprotocols.
Multiprocessor system is made up of two or more main processing elements with similar capabilities running under a single operation system, and the processing elements communicate and cooperate with each other when da...
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ISBN:
(纸本)0769520510
Multiprocessor system is made up of two or more main processing elements with similar capabilities running under a single operation system, and the processing elements communicate and cooperate with each other when data or control dependency. We discuss how to implement an affective multiple buses arbiter for the multiprocessor system. the arbitration of bus is based on two-stage arbitration logic control in interprocessor communication network. For the performance comparison, we analyze the message-transmission rate among processors for the proposed arbiter and the crossbar-based ones.
Firewalls offer a protection for private networks against both internal and external attacks. However, configuring firewalls to ensure the protections is a difficult task. the main reason is the lack of methodology to...
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Firewalls offer a protection for private networks against both internal and external attacks. However, configuring firewalls to ensure the protections is a difficult task. the main reason is the lack of methodology to analyze the security of firewall configurations. IP spoofing attack is an attack in which an attacker can impersonate another person towards a victim. We propose a new methodology for verifying the vulnerability of firewall configurations to IP spoofing attack and for synthesizing IP spoofing-free configurations. Our methodology is based on graph theory, which provides a simple and intuitive approach to the vulnerability analysis of the attack.
Mobile terminals such as mobile phones are adopting a dual core processor having MPU core and DSP core inside. Dual core processor significantly benefits mobile terminals in terms of performance and power consumption....
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Mobile terminals such as mobile phones are adopting a dual core processor having MPU core and DSP core inside. Dual core processor significantly benefits mobile terminals in terms of performance and power consumption. However it makes the software development more complicated because both MPU and DSP requires its own development process. In order to improve the efficiency of software development with dual core processor, we propose a DSP scripting language and its execution environment that enables direct DSP programming from MPU side. We describe the design, implementation, and evaluation of the prototype system.
Summary form only given. Since the introduction of the Java language less then a decade ago, there have been several attempts to create a runtime system for distributed execution of multithreaded Java applications. th...
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Summary form only given. Since the introduction of the Java language less then a decade ago, there have been several attempts to create a runtime system for distributed execution of multithreaded Java applications. the goal of these attempts was to gain increased computational power while preserving Java's convenient parallel programming paradigm. this paper gives a detailed overview of the existing distributed runtime systems for Java and presents a new approach, implemented in a system called JavaSplit. Unlike previous works, which either forfeit Java's portability or introduce unconventional programming constructs, Java-Split is able to execute standard multithreaded Java while preserving portability. JavaSplit works by rewriting the bytecodes of a given parallel application, transforming it into a distributed application that incorporates all the runtime logic. Each runtime node carries out its part of the resulting distributed computation using nothing but its local standard (unmodified) Java virtual machine (JVM).
Berth scheduling and monitoring of the vessel operations are of paramount importance in order to assure faster turnaround time and high productivity of any container terminal. the need for an intelligent system that d...
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Berth scheduling and monitoring of the vessel operations are of paramount importance in order to assure faster turnaround time and high productivity of any container terminal. the need for an intelligent system that dynamically adapts to the changing environment is apparent, as there are a limited number of berths and resources available in container terminals for delivering services to vessels. We discuss how BDI (Beliefs, Desires and Intentions) agents can be supported with Neural Network and fuzzy logic in a collaborative environment of a multi agents system for the scheduling and monitoring of vessel berths in container ports. Straightforward plans are handled by the generic BDI architecture. Complex planning which requires the learning and adaptability behavior is modeled with neural networks. Beliefs with fuzzy scenarios are modeled with fuzzy logic enabling agents to make rational decisions in the environment of uncertainty. Agents can autonomously adapt to the changing environment in assigning berths for vessels.
the focus is on the mechanism that supports the provision of the adequate service level by relying on Web system architecture with multinode clustering. Replication of Web documents can improve both performance and re...
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the focus is on the mechanism that supports the provision of the adequate service level by relying on Web system architecture with multinode clustering. Replication of Web documents can improve both performance and reliability of the Web service. Server selection algorithms allow Web clients to select one of the replicated servers which is "close " to them and thereby minimize the response time of the Web service.
the services in the OSGi framework environment are deployed dynamically according to the service gateway and the life-cycle of a service bundle. Services also have interactions with other services. In this paper, we p...
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the services in the OSGi framework environment are deployed dynamically according to the service gateway and the life-cycle of a service bundle. Services also have interactions with other services. In this paper, we propose a bundle authentication mechanism considering characteristics for the home gateway environment. We design the key exchange mechanism for exchanging a key and propose the service bundle authentication mechanism based on MAC that use a shared secret created in the bootstrapping step. Service bundle authentication mechanism we propose is more efficient than PKI-based bundle authentication mechanism or RSH protocol in the service platform, which has restricted resources such as storage space and operations.
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