Current architectures and data flow models for access control are based on request response communication. In stateful or session-based applications monitoring access rights over time this results in polling of author...
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ISBN:
(数字)9783030397494
ISBN:
(纸本)9783030397494;9783030397487
Current architectures and data flow models for access control are based on request response communication. In stateful or session-based applications monitoring access rights over time this results in polling of authorization services and for Attribute-Based Access Control (ABAC) in the polling of policy information points. This introduces latency or increased load due to polling. Attribute-Stream-based Access Control (ASBAC) is an authorization model based on a publish subscribe pattern mitigating these bottlenecks. ASBAC allows the quasi real time consideration of attribute data streams for access control decisions, such as internet-of-things (IoT) sensor data. This paper introduces the Structure and Agency Policy Language (SAPL) for implementing ASBAC. In addition, the paper describes how ASBAC with SAPL can be implemented by applying a reactive programming model and describes key algorithms for evaluating SAPL policies.
We propose a synchronous cooperative threading model for a programming language called MSSL. In MSSL, threads are executed cooperatively by a round-robin scheduler. Meanwhile, shared data between threads does not requ...
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ISBN:
(纸本)9781450395175
We propose a synchronous cooperative threading model for a programming language called MSSL. In MSSL, threads are executed cooperatively by a round-robin scheduler. Meanwhile, shared data between threads does not require the locking primitives for protection. This result is achieved by introducing a new type of smart pointers, named Trc, that combines sharing and mutability. Furthermore, using the notion of logical time, called instants, threads can progress synchronously with a consistent view of the state of signals. Signals are powerful, flexible, and have compelling means of communication. In this paper, we present a subset of the formal semantics of MSSL in the format of structural operational semantics.
Various types of data are generated through IoT sensors or wearable devices as well as existing mobile and PC devices, and the amount of data to be processed in real-time has increased to quickly show information chan...
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ISBN:
(纸本)9781538650417
Various types of data are generated through IoT sensors or wearable devices as well as existing mobile and PC devices, and the amount of data to be processed in real-time has increased to quickly show information changes to users. reactive programming is a method for asynchronous programming among developers. It can process many threads efficiently with a small quantity of system resources and can process partial data changes in real-time without changing the whole system. In this paper, we propose an interface design for real-time data exchange server based on HL7 FHIR medical data.
In addition to large-scale computers, multicore processors have taken a significant part in all kinds of devices, from personal computers to cell phones. Although programming techniques for parallel systems exist for ...
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ISBN:
(纸本)9789532330991
In addition to large-scale computers, multicore processors have taken a significant part in all kinds of devices, from personal computers to cell phones. Although programming techniques for parallel systems exist for a while, the development of applications that can appropriately utilize multicores is still challenging in many aspects, especially for full exploitation of the computational resources. Additionally, another challenge is the efficient and easy programming of heterogeneous systems for the complete exploitation of silicon resources. Solutions to making parallel programming more developer-friendly are various programming models that abstract parallelism and concurrency. Implementations of those models need to extend even to lower layers of software parallelism and hardware parallelism as well. This paper gives an overview of parallel architectures and trending programming models for such processing units and systems. It also presents challenges to scalability and portability in parallel systems and presents up to date trends in heterogeneous systems that heavily exploit parallelism.
We are interested in web orchestration, which is the problem of appropriately handling the asynchronous events appearing in program executions. It is known be one of the major difficulties of web programming (see call...
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ISBN:
(纸本)9781450351911
We are interested in web orchestration, which is the problem of appropriately handling the asynchronous events appearing in program executions. It is known be one of the major difficulties of web programming (see callback hell [9, 11]).
Arrowized Functional reactive programming (AFRP) is one approach to writing reactive programs declaratively, based on the arrows abstraction in Haskell. While AFRP elegantly expresses the relationships between inputs ...
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ISBN:
(纸本)9798400702983
Arrowized Functional reactive programming (AFRP) is one approach to writing reactive programs declaratively, based on the arrows abstraction in Haskell. While AFRP elegantly expresses the relationships between inputs and outputs of a reactive system, naive implementations suffer from poor performance. In particular, the loop combinator depends on lazy semantics: this inflicts the overheads of lazy evaluation and simultaneously prevents existing optimisation techniques from being applied to it. We present a novel program transformation which utilises the Arrow and ArrowLoop laws to transform typical uses of loop into restricted forms that have an execution order that is known at compile-time and therefore can be executed strictly. We evaluate the performance gained from our transformations and prove that the transformations are correct.
We present the design of a Remus, a virtual machine for reactive (RP) programs - signal-based programs that react automatically to changes - that is currently under development. The design of Remus been tailored speci...
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ISBN:
(纸本)9798400706349
We present the design of a Remus, a virtual machine for reactive (RP) programs - signal-based programs that react automatically to changes - that is currently under development. The design of Remus been tailored specifically for reactive programs: it has a dedicated instruction set and memory model that is compatible with the model of reactive programming. The virtual machine allows reactive programs to be evaluated without needing to compile them to native code, nor by running them on an existing (general-purpose) virtual machine that is not specific to RP. The model of the virtual machine makes it possible to reason over the various behavioural aspects of a reactive program, such as memory consumption, in a language-agnostic way. As an example, we propose a static analysis that aims to eliminate dynamic allocations that occur in dynamic reactive programs: i.e., programs where the dependencies between the signals that make up a program changes at run-time. We show that our virtual machine, supplemented by the results of the analysis, allows for (well-behaved) reactive programs to be evaluated in constant space (i.e. in bounded memory) even when dependencies change or new signals are created programmatically.
Complex event processing (CEP) and reactive Languages (RLs) are examples of solutions for the so-called reactive applications. Such applications are designed to detect and react to changes or event occurrences as they...
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ISBN:
(纸本)9781450376518
Complex event processing (CEP) and reactive Languages (RLs) are examples of solutions for the so-called reactive applications. Such applications are designed to detect and react to changes or event occurrences as they happen in a timely fashion. Both CEP and RLs have been developed by different communities, yet some researchers agree that they share certain aspects and could perhaps be integrated. With that in mind, we developed a JavaScript library called *** that leverages the well-known reactive Extensions for JavaScript (RxJS) to offer not only general-purpose stream operations but also CEP ones. The fact of being a JavaScript library allows *** to be used in Web applications and easily embedded into mobile applications. Therefore, it opens many possibilities for CEP in mobile client applications. It also raises the concern of energy efficiency since CEP applications commonly have to deal with a significant number of events, and its continuous operations on data flows may incur significant processing. Even though *** has been designed after RxJS, it was conceived in a loosely coupled way that the underlying reactive library should be easily replaced if needed. In addition to presenting the *** library, in this paper, we investigate if there is any significant change in performance by running an experiment where the replacement of the reactive library used in *** is the main factor analyzed. The experiment was executed in different Android devices, focusing specifically on energy consumption, an essential non-functional requirement in the smartphone realm.
High resource utilization is important to operate compute infrastructures and data centers efficiently. High utilization is achieved by multiplexing several applications over the same physical infrastructure. Yet, wit...
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ISBN:
(纸本)9781450369862
High resource utilization is important to operate compute infrastructures and data centers efficiently. High utilization is achieved by multiplexing several applications over the same physical infrastructure. Yet, with this approach, the different requirements of each application have to be taken into account when scheduling resources. We propose GRASS, a reactive domain-specific abstraction that allows specifying application-tailored resource scheduling policies. We demonstrate how the declarative approach of GRASS enables extension and composition of scheduling policies. Our evaluation shows the performance benefits of considering application-specific information in a composition of scheduling policies that adapt at run time.
A signal in reactive programming (RP) is a function of time whose value is updated automatically without performing explicit re-assignments. SignalJ, a Java-based RP language, provides persistent signals, whose update...
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ISBN:
(纸本)9781450399111
A signal in reactive programming (RP) is a function of time whose value is updated automatically without performing explicit re-assignments. SignalJ, a Java-based RP language, provides persistent signals, whose update histories constitute time-series data, i.e., a signal is a function of a specified (possibly past) time. These update histories are stored in a time-series database to facilitate the use of persistent signals in an open, distributed setting. However, currently SignalJ is only used in local systems, and there are several obstacles to making it applicable to distributed systems. In this study, we address this problem by proposing a distributed architecture for the SignalJ runtime platform. This architecture includes an ID resolver that makes persistent signals location-transparent and supports a distributed update propagation mechanism that makes distributed time-series data consistent. We realize this architecture by extending the SignalJ compiler and its runtime library as well as providing an add-on to the time-series database. The effectiveness of this architecture is demonstrated by implementing a simple IoT application using this extension.
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