TOP-C is a task-oriented parallel C interface. It presents a master-slave task architecture that greatly eases the parallelization of code. It is intended for applications where a compiler would have difficulty recogn...
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ISBN:
(纸本)0818675829
TOP-C is a task-oriented parallel C interface. It presents a master-slave task architecture that greatly eases the parallelization of code. It is intended for applications where a compiler would have difficulty recognizing opportunities for data-parallelism. The model has been implemented for both shared memory processors and networks of workstations. There is also a sequential version useful during development, which runs the same application code. Ease-of-use has been a strong motivation behind its design. For this reason, TOP-C is organized in a SPMD style, with one primary subroutine call to invoke it. Its main features are: (a) task-parallelism, (b) a single shared, global data structure, and (c) restricted master-slave communication.
The term resiliency has been used in many fields like child psychology, ecology, business, and several others, with the common meaning of expressing the ability to successfully accommodate unforeseen environmental per...
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ISBN:
(纸本)9781424437511
The term resiliency has been used in many fields like child psychology, ecology, business, and several others, with the common meaning of expressing the ability to successfully accommodate unforeseen environmental perturbations or disturbances. The adjective resilient has been in use for decades in the field of dependable computing systems however essentially as a synonym of fault-tolerant, thus generally ignoring the unexpected aspect of the phenomena the systems may have to face. These phenomena become of primary relevance when moving to systems like the future large, networked, evolving systems constituting complex information infrastructures - perhaps involving everything from super-computers and huge server "farms" to myriads of small mobile computers and tiny embedded devices, with humans being central part of the operation of such systems. Such systems are in fact the dawning of the ubiquitous systems that will support Ambient Intelligence. With such ubiquitous systems, what is at stake is to maintain dependability, i.e., the ability to deliver service that can justifiably be trusted, in spite of continuous changes. Therefore the term resilience and resilient computing can be applied to the design of ubiquitous systems and defined as the search for the following property: the persistence of service delivery that can justifiably be trusted, when facing changes. Changes may be of different nature, with different prospect and different timing. Therefore the design of ubiquitous systems requires the mastering of many, often separated, engineering disciplines that span from advanced probability to logic, from human factors to cryptology and information security and to management of large projects. From an educational point of view, very few, if any, Universities are offering a comprehensive and methodical track that is able to provide students with a sufficient preparation that makes them able to cope with the challenges posed by the design of ubiquitous systems.
Motivated by the manipulation of nanoscale materials, recent investigations have focused on hybrid systems where passive elements incapable of movement, called tiles, are manipulated by one or more mobile entities, ca...
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ISBN:
(纸本)9781665497473
Motivated by the manipulation of nanoscale materials, recent investigations have focused on hybrid systems where passive elements incapable of movement, called tiles, are manipulated by one or more mobile entities, called robots, with limited computational capabilities. Like in most self-organizing systems, the fundamental concern is with the (geometric) shapes created by the position of the tiles;among them, the line is perhaps the most important. The existing investigations have focused on formation of the shape, but not on its reconfiguration following the failure of some of the tiles. In this paper, we study the problem of maintaining a line formation in presence of fully dynamic failures: any tile can stop functioning at any time. We show how this problem can be solved by a group of very simple robots, with the computational power of deterministic finite automata.
In a real-rime system, tasks are constrained by global end-to-end (E-T-E) deadlines. In order to cater for high task schedulability, these deadlines must be distributed over component tasks in an intelligent way. In t...
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ISBN:
(纸本)0769501435
In a real-rime system, tasks are constrained by global end-to-end (E-T-E) deadlines. In order to cater for high task schedulability, these deadlines must be distributed over component tasks in an intelligent way. In this paper, we present an improved version of the slicing technique and extend it to heterogeneous distributed hard real-time systems. The salient feature of the new technique is that it utilizes adaptive metrics for assigning local task deadlines. Using experimental results rue show that the new technique exhibits superior performance with respect to the success ratio of a heuristic scheduling algorithm. For smaller systems, the new adaptive metric outperforms a previously-proposed adaptive metric by 300%, and existing non-adaptive metrics by more than an order of magnitude. In addition, the new technique is shown to be extremely robust for various system configurations.
software transactional memory (STM) is one of the promising models in parallel programming for multi-core processor system and has being studied by many researchers. Memory management is an important aspect of STM sys...
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ISBN:
(纸本)9780769541105
software transactional memory (STM) is one of the promising models in parallel programming for multi-core processor system and has being studied by many researchers. Memory management is an important aspect of STM system design which affects the performance of the whole STM system directly. This paper presents the design and implementation of an effective memory manager. It uses private heap to manage transactions' memory space of each thread and a global heap to manage the whole memory space in STM system. Algorithms ensure that the memory access is no-blocking. Tests show that performance of the memory manager is satisfying.
Multicore systems have become standard for desktop computers today. Current operating systems and software development tools provide straightforward means to use the additional computing power. However, a more fundame...
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ISBN:
(纸本)9780769535739
Multicore systems have become standard for desktop computers today. Current operating systems and software development tools provide straightforward means to use the additional computing power. However, a more fundamental change in the design and development of software is required to fully exploit the power of multicore systems. Furthermore, the fast growing market of embedded systems is currently largely unaffected by the introduction of multicore systems. This will change quickly in the future, which will mean that there will be a demand on efficient development of reliable embedded software that can give real-time guarantees and exploit the available power on multicore systems. The JEOPARD project addresses this demand by developing Java software tools to exploit multicore power while ensuring correctness and predictable timing. This paper gives an overview of the JEOPARD project and focuses on key technical issues such as real-time scheduling and real-time garbage collection on multi-core systems.
This work highlights and takes aim at the most critical security aspects required for two different types of distributedsystems for scientific computation. It covers two open-source systems written in Java: a demand-...
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ISBN:
(纸本)9780769534725
This work highlights and takes aim at the most critical security aspects required for two different types of distributedsystems for scientific computation. It covers two open-source systems written in Java: a demand-driven system - General Intensional Programming System (GIPSY) and a pipelined system - distributed Modular Audio Recognition Framework (DMARF), which are the distributed scientific computational engines used as case studies with respect to the security aspects. More specific goals include data/demand integrity, data/demand origin authentication, confidentiality, high availability, and malicious code detection. We address some of the goals to a degree, some with the Java Data Security Framework (JDSF) as a work-in-progress.
We introduce Virtual Leashing,l a new technique for software protection and control. The leashing process removes small fragments of code, pervasive throughout the application, and places them on a secure server. The ...
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We introduce Virtual Leashing,l a new technique for software protection and control. The leashing process removes small fragments of code, pervasive throughout the application, and places them on a secure server. The secure server provides the missing functionality, but never the missing code. Reverse engineering the missing code, even with full tracing of the program's execution and its communication with the server, is computationally hard. Moreover, the server provides the missing functionality asynchronously: the application's performance is independent (within reason) of the secure server's speed. For example, the server might reside on a slow inexpensive chip or a remote Internet server. Leashing makes only modest demands on communication bandwidth, space, and computation. (C) 2006 Elsevier Inc. All rights reserved.
The research topic of software architectures is increasing its importance, as softwaresystems become more and more complex, difficult to understand, and too expensive to design from scratch. It is becoming clear that...
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ISBN:
(纸本)0818680431
The research topic of software architectures is increasing its importance, as softwaresystems become more and more complex, difficult to understand, and too expensive to design from scratch. It is becoming clear that it is possible to reuse and adapt already existing software architectures, if adequate techniques are applied during the development process. We discuss how a method based on a formal design notation supports specification, design, verification, and especially reuse of a software architecture. Our method consists of analyzing a formal specification written in Z to produce a formal design document written in Larch. The use of two different formal notations allows us to exploit specific technique and tools to help a designer in reasoning on and verifying properties and features of a software architecture document. To validate our approach we present a formal treatment of a software architecture which has been reused in real development processes.
software Defined Networking(SDN) is a novel network architecture proposed by Stanford in 2008, which decouples control plane and data plane separately. SDN comes with logically centralized view of the whole network st...
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ISBN:
(纸本)9781538637906
software Defined Networking(SDN) is a novel network architecture proposed by Stanford in 2008, which decouples control plane and data plane separately. SDN comes with logically centralized view of the whole network status and flexible control of packet switching, providing more possibilities of manipulating network in large-scale cloud systems. Scheduling algorithms impact the network performance significantly, especially for SDN-based cluster systems. However, finding an appropriate scheduling algorithm for heterogeneous network environments is an NP problem, where Quality-of-Service(QoS) needs to be ensured efficiently in these systems. Existing solutions rarely take into account of fine-grained bandwidth information and the lack of global network information also reasons why bandwidth is not widely used in scheduling. To address this problem, we proposed a new scheduling approach called BAHS, which is a comprehensive scheduling approach built in SDN environment. The main idea of BAHS is choosing proper tasks and their corresponding paths with the lowest interference. To estimate potential path conflicts, BAHS incorporates the state-of-the-art solution such as Dynamic Online Routing Algorithm(DORA). To demonstrate the effectiveness of our proposed approach, we conduct several simulations based on Mininet. Compared to previous approaches, BAHS improves the completion time and local rate of all tasks with QoS guarantee by up to 14.49% and 12.76%, respectively.
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