共查询到18条相似文献,搜索用时 62 毫秒
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黄军 《电脑编程技巧与维护》2017,(22)
随着时代的发展,程序设计模型也在不断新旧完善,从当前的数据流模型的分析出发,结合其运行机理、内存模型、接口等方面,探讨了具有数据流特征的Java并行程序设计模型,阐述了数据流重要的多态语言特征,通过这些特征提出了对程序的运行有针对性的优化意见,从而达到提升程序性能的作用. 相似文献
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Java存储模型是Java语言和Java虚拟机研究中的核心关键部分,目前Java语言规范中的存储模型不能保证Java技术所必需的语义特性,而且不利于Java虚拟机的性能优化.提出了一种新的Java存储模型,该模型取消了规范中Java存储模型中对存储密致性的要求,保证了Location一致性;同时根据Java语义的要求,对Java语言中不同类型的变量详细规定了多线程存储操作的行为规则.该模型不仅能保证Java程序的正确性,同时能有效提高Java程序的运行效率.最后通过仿真实验验证了该存储模型的关键特性. 相似文献
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本文针对Java智能卡的安全问题,提出了一种新的解决方案--将可信计算技术引入到Java智能卡的设计与实现中,以可信计算在安全认证方面的优势来解决智能卡的安全问题.文章首先从硬件方面对该方案的可行性进行了分析,然后从类库、虚拟机和运行时环境三个方面介绍了如何实现Java智能卡,最后并着重介绍了可信机制的构建. 相似文献
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同步开销是影响并行程序性能的一个重要方面,如果同步操作出现在循环中,将会使这种影响进一步扩大.为了降低循环中同步操作的开销,本文提出一种利用即时编译器外提Java程序中循环内同步操作的优化算法,并在实际的Java虚拟机中实现.该算法在保证程序语义不变的前提下,大量减少运行时实际执行的同步操作数量,降低同步开销,并能保证外提变换后同步代码块不会太大而降低程序的并发度.实验结果表明该算法能提高程序的整体性能,并且不降低程序的可扩放性. 相似文献
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嵌入式Java虚拟机优化研究 总被引:1,自引:0,他引:1
为了改进手机中Java小程序的运行效率,基于KVM提出一种嵌入式Java虚拟机优化方案.在此方案中对解释器进行了改造,引入编译技术,并对KVM运行时内存的分配与回收方式作了改进.最后对比分析了在基准测试中KVM与优化方案的性能结果. 相似文献
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Sang Boem Lim Hanku Lee Bryan Carpenter Geoffrey Fox 《The Journal of supercomputing》2008,43(2):165-182
The paper research is concerned with enabling parallel, high-performance computation—in particular development of scientific
software in the network-aware programming language, Java. Traditionally, this kind of computing was done in Fortran. Arguably,
Fortran is becoming a marginalized language, with limited economic incentive for vendors to produce modern development environments,
optimizing compilers for new hardware, or other kinds of associated software expected of by today’s programmers. Hence, Java
looks like a very promising alternative for the future.
The paper will discuss in detail a particular environment called HPJava. HPJava is the environment for parallel programming—especially data-parallel scientific programming—in Java. Our HPJava is
based around a small set of language extensions designed to support parallel computation with distributed arrays, plus a set
of communication libraries. A high-level communication API, Adlib, is developed as an application level communication library suitable for our HPJava. This communication library supports
collective operations on distributed arrays. We include Java Object as one of the Adlib communication data types. So we fully support communication of intrinsic Java types, including primitive
types, and Java object types. 相似文献
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主要讨论了如何在浏览器中使用Java插入件以便增强浏览的功能,使得Web页面作者右以部署基于Java2的applet,使用Java2所提供的新特性。 相似文献
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Model Checking Programs 总被引:10,自引:0,他引:10
Willem Visser Klaus Havelund Guillaume Brat SeungJoon Park Flavio Lerda 《Automated Software Engineering》2003,10(2):203-232
The majority of work carried out in the formal methods community throughout the last three decades has (for good reasons) been devoted to special languages designed to make it easier to experiment with mechanized formal methods such as theorem provers, proof checkers and model checkers. In this paper we will attempt to give convincing arguments for why we believe it is time for the formal methods community to shift some of its attention towards the analysis of programs written in modern programming languages. In keeping with this philosophy we have developed a verification and testing environment for Java, called Java PathFinder (JPF), which integrates model checking, program analysis and testing. Part of this work has consisted of building a new Java Virtual Machine that interprets Java bytecode. JPF uses state compression to handle big states, and partial order and symmetry reduction, slicing, abstraction, and runtime analysis techniques to reduce the state space. JPF has been applied to a real-time avionics operating system developed at Honeywell, illustrating an intricate error, and to a model of a spacecraft controller, illustrating the combination of abstraction, runtime analysis, and slicing with model checking. 相似文献
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Implementing a concurrent programming language such as Java by means of a translator to an existing language is attractive as it provides portability over all platforms supported by the host language and reduces development time—as many low‐level tasks can be delegated to the host compiler. The C and C++ programming languages are popular choices for many language implementations due to the availability of efficient compilers on a wide range of platforms. For garbage‐collected languages, however, they are not a perfect match as no support is provided for accurately discovering pointers to heap‐allocated data on thread stacks. We evaluate several previously published techniques and propose a new mechanism, lazy pointer stacks, for performing accurate garbage collection in such uncooperative environments. We implemented the new technique in the Ovm Java virtual machine with our own Java‐to‐C/C++ compiler using GCC as a back‐end compiler. Our extensive experimental results confirm that lazy pointer stacks outperform existing approaches: we provide a speedup of 4.5% over Henderson's accurate collector with a 17% increase in code size. Accurate collection is essential in the context of real‐time systems, we thus validate our approach with the implementation of a real‐time concurrent garbage collection algorithm. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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为了改进Dalvik虚拟机的性能,提出了一种基于多线程调度机制的Java虚拟机混合并发模式。该模式利用多线程并发调度和热方法表,通过将Java字节码的编译与执行过程相重叠来提高程序的执行效率,进而提升Dalvik虚拟机的处理速度;并对该模式设计与实现的关键技术进行了分析。实验结果表明,混合并发模式能够有效地提高Dalvik虚拟机中Java程序的执行速度。 相似文献
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基于实例学习的可适应性并行任务负荷分配算法能根据应用程序的静态特征估计其运算负荷,选定好的任务负荷分配方案使其多线程并行接近甚至达到最优,它具有低成本和高效率的特点.通过一系列实验,分析研究训练实例的选择对基于实例学习优化的效果的影响,从中总结一些有益的经验,以便进一步提高算法性能. 相似文献
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提出一种基于类文件的Java运行时异常分析技术.它可在没有Java源代码文件的情况下,直接对类文件进行处理,分析可能抛出的异常信息,并根据分析结果在类文件中添加适当的异常追踪代码.这种处理后的类文件可无缝替换原类文件运行,并在运行中抛出异常时,能够给出详尽的异常分析报告,从而提高技术人员调试和开发的效率. 相似文献