Leasing provides a robust mechanism to manage reclamation of remote objects in mobile ad hoc networks. However, applying the leasing semantics on each remote object reference places a considerable burden on developers...
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Cache miss stalls hurt performance because of the large gap between memory and processor speeds - for example, the popular server benchmark SPEC JBB2000 spends 45% of its cycles stalled waiting for memory requests on ...
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Cache miss stalls hurt performance because of the large gap between memory and processor speeds - for example, the popular server benchmark SPEC JBB2000 spends 45% of its cycles stalled waiting for memory requests on the Itanium® 2 processor. Traversing linked data structures causes a large portion of these stalls. Prefetching for linked data structures remains a major challenge because serial data dependencies between elements in a linked data structure preclude the timely materialization of prefetch addresses. This paper presents Mississippi Delta (MS Delta), a novel technique for prefetching linked data structures that closely integrates the hardware performance monitor (HPM), the garbage collector's global view of heap and object layout, the type-level metadata inherent in type-safe programs, and JIT compiler analysis. The garbage collector uses the HPM's data cache miss information to identify cache miss intensive traversal paths through linked data structures, and then discovers regular distances (deltas) between these linked objects. JIT compiler analysis injects prefetch instructions using deltas to materialize prefetch addresses. We have implemented MS Delta in a fully dynamic profile-guided optimization system: the StarJIT dynamic compiler and the ORP Java virtual machine, We demonstrate a 28-29% reduction in stall cycles attributable to the high-latency cache misses targeted by MS Delta and a speedup of 11-14% on the cache miss intensive SPEC JBB2000 benchmark.
The field of software engineering originally concentrated on "programming in the small" emphasizing implementation techniques. Over the last decades, software and systems engineering expanded to a comprehens...
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ISBN:
(纸本)0769529097
The field of software engineering originally concentrated on "programming in the small" emphasizing implementation techniques. Over the last decades, software and systems engineering expanded to a comprehensive engineering discipline. Nowadays software engineering comprises requirements engineering, modeling and design, implementation and testing, installation and maintenance. Software engineering proved to be a key technology;its mastery determines the functioning of modern infrastructures and consumer products. Software development has matured from heuristic practice to an engineering discipline. In the meantime, software engineers can benefit from a solid stock of basic research addressing modeling and design techniques for sequential, concurrent, distributed, and timed systems. Software quality and reliability, security and safety, the management of change, reuse and integration pose new requirements to the practice of software engineering. A major challenge consists in integrating the developed theories into a coherent engineering framework accepted by practitioners. Software engineers face different system views described by a variety of graphical and textual formalisms. Software development must safely bridge the system views on different levels of abstraction ranging from high-level specifications to executable code. The system views center around the data model, the communication model, the state transition model, and the trace model. The data model describes the data structure in an abstract or concrete way. The communication model manifests how a component interacts with the environment by exchanging messages. The state transition model describes an abstract implementation where an input affects an update of the internal state and a possible output. The trace model characterizes the operational behaviour of the system by a set of possible runs composed of atomic actions. The lecture classifies different system models and addresses discrete interactive sys
orthogonal and quasi-orthogonal matrices with a limited number of element values and structured in some way are of considerable interest for many technical applications related to image processing and signal coding. T...
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Expressing layer dependencies in Context-oriented programming is cumbersome because until now no facility has been introduced to control the activation and deactivation of layers. This paper presents a novel reflectiv...
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ISBN:
(纸本)1595934804;9781595934802
Expressing layer dependencies in Context-oriented programming is cumbersome because until now no facility has been introduced to control the activation and deactivation of layers. This paper presents a novel reflective interface that provides such control without compromising efficiency. This allows expressing complex application-defined dependencies between layers where the activation or deactivation of a layer requires the activation or deactivation of another one. The activation or deactivation of specific layers can also be prohibited based on application-defined conditions. Copyright 2007 ACM.
SAC is a purely functional array processing language designed with numerical applications in mind. It supports generic, high-level program specifications in the style of APL. However, rather than providing a fixed set...
Shape-generic programming and high run time performance do match if generic source code is systematically specialised into nongeneric executable code. However, as soon as we drop the assumption of whole-world knowledg...
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Let a = {σi｜ i ∈ I} be some partition of the set of all primes P, G a finite group and σ（G） = {σi｜σi ∩ π （G） ≠ Ф}. A set H of subgroups of G is said to be a complete Hall or-set of G if every member ≠...
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Let a = {σi｜ i ∈ I} be some partition of the set of all primes P, G a finite group and σ（G） = {σi｜σi ∩ π （G） ≠ Ф}. A set H of subgroups of G is said to be a complete Hall or-set of G if every member ≠ 1 of H is a Hall σi-subgroup of G for some σi ∈ σ and H contains exactly one Hall σi-subgroup of G for every σi ∈ σ（G）. A subgroup H of G is said to be： σ-semipermutablc in G with respect to H if HHi x = Hi x H for all x ∈ G and all x ∈ G and all Hi ∈H such that （｜H｜, ｜Hi｜） = 1; σ-semipermutable in G if H is σ-semipermutable in G with respect to some complete Hall σ-set of G. We study the structure of G being based on the assumption that some subgroups of G are σ-semipermutable in G.
the issue of ensuring the reliability of the functioning of global systems of remote online monitoring of the condition of patients is considered. Remote monitoring is in demand when supervision the health status of d...
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