Recent popularity of Java programming language has brought the automatic dynamic memory management (a.k.a., the garbage collection) into the mainstream, Traditional garbage collectors suffer from long garbage collecti...
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ISBN:
(纸本)0780373715
Recent popularity of Java programming language has brought the automatic dynamic memory management (a.k.a., the garbage collection) into the mainstream, Traditional garbage collectors suffer from long garbage collection pauses (stop-the-world mark-sweep algorithm) or inability of collecting cyclic garbage (reference counting approach). Generational garbage collection, however, is based only on the weak generational hypothesis that most objects die young. In this paper, the performance evaluation of a new multithreaded concurrent generational garbage collector (MCGC) based on mark-sweep with the assistance of reference counting is reported. The MCGC can take advantage of multiple CPUs in an SMP system and the merits of light weight processes. Furthermore, the long garbage collection pause can be reduced and the garbage collection efficiency can be enhanced. Measurement results indicate that the MCGC improves the garbage collection pause time up to 96.75% over the traditional stop-the-world mark-sweep garbage collector. Moreover, the MCGC receives minimal time and space penalties as shown in the report of the total execution time, the memory footprint and the sticky reference count rate.
Deadlock in multithreaded programs is an increasingly important problem as ubiquitous multicore architectures force parallelization upon an ever wider range of software. This paper presents a theoretical foundation fo...
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ISBN:
(纸本)9781605583792
Deadlock in multithreaded programs is an increasingly important problem as ubiquitous multicore architectures force parallelization upon an ever wider range of software. This paper presents a theoretical foundation for dynamic deadlock avoidance in concurrent programs that employ conventional mutual exclusion and synchronization primitives (e. g., multithreaded C/Pthreads programs). Beginning with control flow graphs extracted from program source code, we construct a formal model of the program and then apply Discrete Control Theory to automatically synthesize deadlock-avoidance control logic that is implemented by program instrumentation. At run time, the control logic avoids deadlocks by postponing lock acquisitions. Discrete Control Theory guarantees that the program instrumented with our synthesized control logic cannot deadlock. Our method furthermore guarantees that the control logic is maximally permissive: it postpones lock acquisitions only when necessary to prevent deadlocks, and therefore permits maximal run-time concurrency. Our prototype for C/Pthreads scales to real software including Apache, OpenLDAP, and two kinds of benchmarks, automatically avoiding both injected and naturally occurring deadlocks while imposing modest runtime overheads.
In this paper, an automated measurement system for wireless transmitters with different frequencies, modulation types, and bit rates is introduced. Using VISA (Virtual Instrument Software Architecture) and COM API (Ap...
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ISBN:
(纸本)9781424411351
In this paper, an automated measurement system for wireless transmitters with different frequencies, modulation types, and bit rates is introduced. Using VISA (Virtual Instrument Software Architecture) and COM API (Application programming Interface), the system can operate the spectrum analyzer, vector signal analyzer (VSA89600), oscilloscope according to the user's requirements. With the help of peripheral circuits and multithreaded programming techniques, the automated measurement system can measure from DC to radio frequency signals;perform spectrum and modulation quality analysis of EUT (Equipment under test) automatically;during the measurement process, operating status of EUT can be real time monitored, if the operating status of EUT is abnormal, EUT would be shut down immediately.
Due to the emerging multimedia technology, multimedia files such as text, image, audio and video files are widely used. These multimedia files take hundreds time more space as compared to early day's media files. ...
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ISBN:
(纸本)9781424455324
Due to the emerging multimedia technology, multimedia files such as text, image, audio and video files are widely used. These multimedia files take hundreds time more space as compared to early day's media files. Thus, demand for efficient compression algorithm is in great needs. Currently, a lot of general purpose multi-core processor machines and systems are widely available. However, many compression algorithms have not been taking advantage of being optimized for these processors. This paper explores the multithreaded compression algorithm to take advantages offered by multi-core processor.
Symmetric multi-processor (SMP) systems, or multiple-CPU servers, are suitable for implementing parallel algorithms because they employ dedicated communication devices to enhance the inter-processor communication band...
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Symmetric multi-processor (SMP) systems, or multiple-CPU servers, are suitable for implementing parallel algorithms because they employ dedicated communication devices to enhance the inter-processor communication bandwidth, so that a better performance can be obtained. However, the cost for a multiple-CPU server is high and therefore, the server is usually shared among many users. The work-load due to other users will certainly affect the performance of the parallel programs so it is desirable to derive a method to optimize parallel programs under different loading conditions. In this paper, we present a simple method, which can be applied in SPMD type parallel programs, to improve the speedup by controlling the number of threads within the programs. (C) 2001 Elsevier Science B.V. All rights reserved.
Multiagent algorithms are widely used in computational economics and other social sciences to solve theoretical and practical problems. Because such algorithms are inherently concurrent and multithreaded, Ada's co...
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ISBN:
(纸本)9781605584751
Multiagent algorithms are widely used in computational economics and other social sciences to solve theoretical and practical problems. Because such algorithms are inherently concurrent and multithreaded, Ada's constructs for handling communications between concurrent processes and avoiding interference between them make the language very well suited to solving these problems, particularly given developments in multi-core CPU chip-making. This paper provides a concrete example of how Ada assists in solving problems in computational economics and related disciplines that work with multiagent systems. Solving a simple problem illustrates visualizing the agents as Ada tasks, using UML use cases and synchronization diagrams to design the communications patterns between agents, and applying protected objects and functions to avoid computational indeterminacy.
Often there is a need to have many compilers in the same machine to compile programs in different languages at the same time. This paper focuses on solving the problem of storage and portability of compilers. The user...
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ISBN:
(纸本)9781479939145
Often there is a need to have many compilers in the same machine to compile programs in different languages at the same time. This paper focuses on solving the problem of storage and portability of compilers. The user without having to install any compiler needs to submit the program into the user interface provided. The controller will then decide which compiler server the program should be assigned to compile, depending on the load of backend compilers. The compiler server will compile and run the program. The output is then given back to the user. The distribution of load by the controller is also tested by calculating the total response time of the programs in both serial and parallel program allocation to compilation tier.
BCI (called Brain-Computer Interface) is an interface that allows direct communication between human brain and an external device. It bases on EEG signal collection, processing and classification. In this paper a comp...
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ISBN:
(纸本)9780819491718
BCI (called Brain-Computer Interface) is an interface that allows direct communication between human brain and an external device. It bases on EEG signal collection, processing and classification. In this paper a complete BCI system is presented which classifies EEG signal using artificial neural networks. For this purpose we used a multi-layered perceptron architecture trained with the RProp algorithm. Furthermore a simple multi-threaded method for automatic network structure optimizing was shown. We presented the results of our system in the opening and closing eyes recognition task. We also showed how our system could be used for controlling devices basing on imaginary hand movements.
Model-Predictive Control (MPC) is a popular advanced control technique, known for its robustness and simplicity in taking control constraints into account. In recent years, the interest grows in applying interval meth...
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ISBN:
(纸本)9783319321523;9783319321516
Model-Predictive Control (MPC) is a popular advanced control technique, known for its robustness and simplicity in taking control constraints into account. In recent years, the interest grows in applying interval methods to compute MPC. The paper applies interval methods in a simple case. Numerical results for a benchmark problem are presented.
Software programming for concurrent execution is not a simple task. The main issue related to this work is the lack of visibility of the multiple and parallel execution over the threads. Multi core processor technolog...
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ISBN:
(纸本)9783319029573;9783319029580
Software programming for concurrent execution is not a simple task. The main issue related to this work is the lack of visibility of the multiple and parallel execution over the threads. Multi core processor technology is a reality nowadays and the only way to use modern hardware at its full capacity lays in the use of concurrent software. In this paper, we present a new 3D framework, based on hand gestures that manipulate multiple threads of execution and to deal with the visibility issues, using a 3D programming environment.
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