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120 results on '"active objects"'

1. Proving Correctness of Parallel Implementations of Transition System Models.

Author

de Boer, Frank, Johnsen, Einar Broch, Pun, Violet Ka I, and Tapia Tarifa, Silvia Lizeth

Subjects
*PARALLEL processing, *PROOF of concept, *SIMULATION methods & models, *SEMANTICS, *MEMORY
Abstract

This article addresses the long-standing problem of program correctness for programs that describe systems of parallel executing processes. We propose a new method for proving correctness of parallel implementations of high-level models expressed as transition systems. The implementation language underlying the method is based on the concurrency model of actors and active objects. The method defines program correctness in terms of a simulation relation between the transition system that specifies the program semantics of the parallel program and the transition system that is described by the correctness specification. The simulation relation itself abstracts from the fine-grained interleaving of parallel processes by exploiting a global confluence property of the concurrency model of the implementation language considered in this article. As a proof of concept, we apply our method to the correctness of a parallel simulator of multicore memory systems. [ABSTRACT FROM AUTHOR]

Published
2024
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2. A Survey of Actor-Like Programming Models for Serverless Computing

Author

Spenger, Jonas, Carbone, Paris, Haller, Philipp, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, de Boer, Frank, editor, Damiani, Ferruccio, editor, Hähnle, Reiner, editor, Broch Johnsen, Einar, editor, and Kamburjan, Eduard, editor

Published
2024
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4. Negative space of things : a practice-based research approach to understand the role of objects in the Internet of Things

Author

Shingleton, Duncan James, Speed, Chris, and Martin, Craig

Subjects
745.2, Internet of Things, connecting objects, data flows between objects, networked object, active objects
Abstract

This is a practice-based research thesis situated in the research context of the 'Internet of Things', and critiques contemporary theoretical discourse related to the 21st century turn of connecting everyday objects to the World Wide Web. In the last decade we have seen the 'Internet of Things' articulated predominately through three commercial design fictions, each a response to the shift towards pervasive", "ubiquitous" (Weiser 1991), or "context-ware" (Schilit, 1994) computing; where we inhabit spaces with objects capable of sensing, recording and relaying data about themselves and their environments. Through reflecting upon these existing design fictions, through a new combination of theories and practice-based research that embodies them, this thesis proposes a recovery to understanding the role of objects in the 'Internet of Things', which this author believes has been lost since its conception in the mid 2000s. In 2000, HP Labs presented Cooltown, which addressed what HP identified as the 'convergence of Web technology, wireless networks, and portable client devices provides'. Cooltown's primary discourse was to provide 'new design opportunities for computer/communications systems, through an infrastructure to support "web presence" for people, places and things.' (Anders 1998; Barton & Kindberg 2002). IBM's Smarter Planet followed this in 2008 and shifted importance from the act of connecting objects to understanding the value of data as it flows between these objects in a network (Castells 1996; Sterling 2005; Latour 2005). Finally, Cisco presented The Internet of Everything in 2012 and moved the argument on one stage further, identifying that the importance of connected objects lies in the sum of their communication across silos of networks, where data can provide potential insight from which you can improve services (Bleecker 2006). Despite these design and theoretical fictions, the affordances of the Internet of Things first proposed in the mid 2000s has regressed from data to product, driven largely by unchanged discourse argued by those designers at its conception and also the enticement of being the next Google acquisition; instead of pigeons reporting on the environmental conditions of a city (Da Costa 2006), we have thermostats controllable from your smartphone (www.scottishpower.co.uk/connect). Therefore the aim of this thesis is to re-examine the initial potential of the Internet of Things, which is tested through a series of design interventions as research for art and design, (produced as part of my EPSRC funded doctoral studies on the Tales of Things and Electronic Memory research project and also whilst employed as a research assistant on two EPSRC funded research programmes of work Sixth Sense Transport, and The Connected High Street), to understand how we use data to allow an alternative discourse to emerge in order to recover the role of a networked object, rather than producing prototypical systems.

Published
2018

5. Information-Flow Control by Means of Security Wrappers for Active Object Languages with Futures

Author

Karami, Farzane, Owe, Olaf, Schneider, Gerardo, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Asplund, Mikael, editor, and Nadjm-Tehrani, Simin, editor

Published
2021
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6. A Hybrid Programming Language for Formal Modeling and Verification of Hybrid Systems

Author

Kamburjan, Eduard, Mitsch, Stefan, and Hähnle, Reiner

Subjects
active objects, differential dynamic logic, hybrid systems, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Electronics, TK7800-8360
Abstract

Designing and modeling complex cyber-physical systems (CPS) faces the double challenge of combined discrete-continuous dynamics and concurrent behavior. Existing formal modeling and verification languages for CPS expose the underlying proof search technology. They lack high-level structuring elements and are not efficiently executable. The ensuing modeling gap renders formal CPS models hard to understand and to validate. We propose a high-level programming-based approach to formal modeling and verification of hybrid systems as a hybrid extension of an Active Objects language. Well-structured hybrid active programs and requirements allow automatic, reachability-preserving translation into differential dynamic logic, a logic for hybrid (discrete-continuous) programs. Verification is achieved by discharging the resulting formulas with the theorem prover KeYmaera X. We demonstrate the usability of our approach with case studies.

Published
2022
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8. A Language-Based Approach to Prevent DDoS Attacks in Distributed Financial Agent Systems

Author

Fazeldehkordi, Elahe, Owe, Olaf, Ramezanifarkhani, Toktam, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Fournaris, Apostolos P., editor, Athanatos, Manos, editor, Lampropoulos, Konstantinos, editor, Ioannidis, Sotiris, editor, Hatzivasilis, George, editor, Damiani, Ernesto, editor, Abie, Habtamu, editor, Ranise, Silvio, editor, Verderame, Luca, editor, Siena, Alberto, editor, and Garcia-Alfaro, Joaquin, editor

Published
2020
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9. Resource Monitoring Using Virtual Ring Navigation Through Mobile Agent for Heterogeneity Oriented Interconnected Nodes

Author

Chowhan, Rahul Singh, Purohit, Rajesh, Kacprzyk, Janusz, Series Editor, Pal, Nikhil R., Advisory Editor, Bello Perez, Rafael, Advisory Editor, Corchado, Emilio S., Advisory Editor, Hagras, Hani, Advisory Editor, Kóczy, László T., Advisory Editor, Kreinovich, Vladik, Advisory Editor, Lin, Chin-Teng, Advisory Editor, Lu, Jie, Advisory Editor, Melin, Patricia, Advisory Editor, Nedjah, Nadia, Advisory Editor, Nguyen, Ngoc Thanh, Advisory Editor, Wang, Jun, Advisory Editor, Panigrahi, Chhabi Rani, editor, Pujari, Arun K., editor, Misra, Sudip, editor, Pati, Bibudhendu, editor, and Li, Kuan-Ching, editor

Published
2019
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10. Summary of: An Evaluation of Interaction Paradigms for Active Objects

Author

Karami, Farzane, Owe, Olaf, Ramezanifarkhani, Toktam, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Ahrendt, Wolfgang, editor, and Tapia Tarifa, Silvia Lizeth, editor

Published
2019
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11. Composable Actor Behaviour

Author

Van den Vonder, Sam, De Koster, Joeri, De Meuter, Wolfgang, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Pandu Rangan, C., Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Pereira, José, editor, and Ricci, Laura, editor

Published
2019
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12. Active Objects for Coordinating BSP Computations (Short Paper)

Author

Hains, Gaétan, Henrio, Ludovic, Leca, Pierre, Suijlen, Wijnand, Hutchison, David, Series Editor, Kanade, Takeo, Series Editor, Kittler, Josef, Series Editor, Kleinberg, Jon M., Series Editor, Mattern, Friedemann, Series Editor, Mitchell, John C., Series Editor, Naor, Moni, Series Editor, Pandu Rangan, C., Series Editor, Steffen, Bernhard, Series Editor, Terzopoulos, Demetri, Series Editor, Tygar, Doug, Series Editor, Weikum, Gerhard, Series Editor, Di Marzo Serugendo, Giovanna, editor, and Loreti, Michele, editor

Published
2018
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13. ACTIVE OBJECTS AND THEIR MODELING WITH USING OF MULTIPROCESS PETRI MULTINETS WITH TIME STAMPS.

Author

Martiník, Ivo

Subjects
*PETRI nets, *PARALLEL programming, *MULTIPROCESSORS, *DISCRETE time filters, *MATHEMATICAL models
Abstract

Petri nets is the well-known mathematical tool for the modeling and verification of parallel systems of all kind. Multiprocess Petri multinets with time stamps (MPTSM) are the newly introduced class of low-level Petri nets, whose definition and the properties are the main topic of this article; they generalize the properties of P/T Petri multiprocess multinets in the area of design, modeling and verification of generally parallel programming systems with the discrete time. The MPTSM with the support of the ASYNC-CALL operation can be then applied into the area of modeling and verification of multithreading programming systems based on the actor model of objectoriented programming, where all object are represented as independent computational entities with discrete time (i.e., active objects) that only respond to the received messages. This fact will be then demonstrated on the simple example of the programming system based on the client-server architecture that is operated in the distributed system environment where all the actors are synchronized in time with the unique central time source. [ABSTRACT FROM AUTHOR]

Published
2018
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15. Actor Garbage Collection Using Vertex-Preserving Actor-to-Object Graph Transformations

Author

Wang, Wei-Jen, Varela, Carlos, Hsu, Fu-Hau, Tang, Cheng-Hsien, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Bellavista, Paolo, editor, Chang, Ruay-Shiung, editor, Chao, Han-Chieh, editor, Lin, Shin-Feng, editor, and Sloot, Peter M. A., editor

Published
2010
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16. Formal modeling and analysis of railway operations with active objects.

Author

Kamburjan, Eduard, Hähnle, Reiner, and Schön, Sebastian

Subjects
*MACROSCOPIC cross sections, *NUCLEAR cross sections, *NUMERICAL analysis, *DATA analysis
Abstract

Abstract We present a comprehensive model of railway operations written in the active object language ABS. The model is based on specifications taken from the rulebooks of Deutsche Bahn AG. It is statically analyzable and executable, hence allows to use static and dynamic analysis within one and the same formalism. We are able to combine aspects of micro- and macroscopic modeling and provide a way to inspect changes in the rulebooks. We illustrate the static analysis capability by a safety analysis based on invariant reasoning that only relies on assumptions about the underlying railway infrastructure instead of explicitly exploring the state space. A concrete infrastructure layout and train schedule can be used as input to the model to examine dynamic properties such as delays. We illustrate the capability for dynamic analysis by demonstrating the effect that different ways of dealing with faulty signals have on delays and propagation of delays. Highlights • Formal verification of railway on the operational level with active objects. • Safety analysis on arbitrary, unbounded networks with deductive verification. • Analysis of capacity and propagation of delays with simulation. • Uniform approach to modeling: Global effects of local changes can be analyzed. [ABSTRACT FROM AUTHOR]

Published
2018
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17. A Survey of Active Object Languages.

Author

DE BOER, FRANK, SERBANESCU, VLAD, HÄHNLE, REINER, HENRIO, LUDOVIC, ROCHAS, JUSTINE, DIN, CRYSTAL CHANG, JOHNSEN, EINAR BROCH, SIRJANI, MARJAN, KHAMESPANAH, EHSAN, FERNANDEZ-REYES, KIKO, and YANG, ALBERT MINGKUN

Subjects
*SOFTWARE engineering, *PARALLEL programs (Computer programs), *CONCURRENT engineering, *PROGRAMMING languages, *COMPUTER programming
Abstract

To program parallel systems efficiently and easily, a wide range of programming models have been proposed, each with different choices concerning synchronization and communication between parallel entities. Among them, the actor model is based on loosely coupled parallel entities that communicate by means of asynchronous messages and mailboxes. Some actor languages provide a strong integration with object-oriented concepts; these are often called active object languages. This article reviews four major actor and active object languages and compares them according to carefully chosen dimensions that cover central aspects of the programming paradigms and their implementation. [ABSTRACT FROM AUTHOR]

Published
2018
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18. A Petri Net Based Modeling of Active Objects and Futures.

Author

de Boer, Frank S., Bravetti, Mario, Lee, Matias D., and Zavattaro, Gianluigi

Subjects
*PETRI nets, *BOTTLENECKS (Manufacturing), *CONCRETE, *MARKING devices, *INFORMATION science
Abstract

We give two different notions of deadlock for systems based on active objects and futures. One is based on blocked objects and conforms with the classical definition of deadlock by Coffman, Jr. et al. The other one is an extended notion of deadlock based on blocked processes which is more general than the classical one. We introduce a technique to prove deadlock freedom of systems of active objects. To check deadlock freedom an abstract version of the program is translated into Petri nets. Extended deadlocks, and then also classical deadlock, can be detected via checking reachability of a distinct marking. Absence of deadlocks in the Petri net constitutes deadlock freedom of the concrete system. [ABSTRACT FROM AUTHOR]

Published
2018
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19. A Hybrid Programming Language for Formal Modeling and Verification of Hybrid Systems

Author

Eduard Kamburjan and Stefan Mitsch and Reiner Hähnle, Kamburjan, Eduard, Mitsch, Stefan, Hähnle, Reiner, Eduard Kamburjan and Stefan Mitsch and Reiner Hähnle, Kamburjan, Eduard, Mitsch, Stefan, and Hähnle, Reiner

Abstract

Designing and modeling complex cyber-physical systems (CPS) faces the double challenge of combined discrete-continuous dynamics and concurrent behavior. Existing formal modeling and verification languages for CPS expose the underlying proof search technology. They lack high-level structuring elements and are not efficiently executable. The ensuing modeling gap renders formal CPS models hard to understand and to validate. We propose a high-level programming-based approach to formal modeling and verification of hybrid systems as a hybrid extension of an Active Objects language. Well-structured hybrid active programs and requirements allow automatic, reachability-preserving translation into differential dynamic logic, a logic for hybrid (discrete-continuous) programs. Verification is achieved by discharging the resulting formulas with the theorem prover KeYmaera X. We demonstrate the usability of our approach with case studies.

Published
2022
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20. Exception Handling and Asynchronous Active Objects: Issues and Proposal

Author

Dony, Christophe, Urtado, Christelle, Vauttier, Sylvain, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Dony, Christophe, editor, Knudsen, Jørgen Lindskov, editor, Romanovsky, Alexander, editor, and Tripathi, Anand, editor

Published
2006
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22. Adaptable Objects for Dependability

Author

Contreras, Jose Lino, Sourrouille, Jean Louis, Goos, Gerhard, editor, Hartmanis, Juris, editor, van Leeuwen, Jan, editor, de Lemos, Rogério, editor, Weber, Taisy Silva, editor, and Camargo, João Batista, Jr., editor

Published
2003
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25. Deductive verification of active objects with Crowbar.

Author

Kamburjan, Eduard, Scaletta, Marco, and Rollshausen, Nils

Subjects
*MODULAR construction
Abstract

We present Crowbar, a deductive verification tool for the Active Object language ABS. Crowbar implements novel specification approaches specifically for distributed systems. For user interaction, counterexamples are presented as executable programs. Crowbar has a modular structure to explore further approaches, and was applied in the largest Active Objects verification study. [ABSTRACT FROM AUTHOR]

Published
2023
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26. Non-regular Process Types

Author

Puntigam, Franz, Amestoy, Patrick, editor, Berger, Philippe, editor, Daydé, Michel, editor, Ruiz, Daniel, editor, Duff, Iain, editor, Frayssé, Valérie, editor, and Giraud, Luc, editor

Published
1999
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32. Abstractions to Control the Future

Author

Fernández Reyes, Francisco Ramón and Fernández Reyes, Francisco Ramón

Abstract

Multicore and manycore computers are the norm nowadays, and users have expectations that their programs can do multiple things concurrently. To support that, developers use concur- rency abstractions such as threads, promises, futures, and/or channels to exchange information. All these abstractions introduce trade-offs between the concurrency model and the language guarantees, and developers accept these trade-offs for the benefits of concurrent programming. Many concurrent languages are multi-paradigm, e.g., mix the functional and object-oriented paradigms. This is beneficial to developers because they can choose the most suitable approach when solving a problem. From the point of view of concurrency, purely functional programming languages are data-race free since they only support immutable data. Object-oriented languages do not get a free lunch, and neither do multi-paradigm languages that have imperative features. The main problem is uncontrolled concurrent access to shared mutable state, which may inadvertently introduce data-races. A data-race happens when two concurrent memory operations target the same location, at least one of them is a write, and there is no synchronisation operation involved. Data-races make programs to exhibit (unwanted) non-deterministic behaviour. The contribution of this thesis is two-fold. First, this thesis introduces new concurrent abstractions in a purely functional, statically typed programming language (Paper I – Paper III); these abstractions allow developers to write concurrent control- and delegation-based patterns. Second, this thesis introduces a capability-based dynamic programming model, named Dala, that extends the applicability of the concurrent abstractions to an imperative setting while maintaining data-race freedom (Paper IV). Developers can also use the Dala model to migrate unsafe programs, i.e., programs that may suffer data-races, to data-race free programs.

Published
2021

34. On the nature of cooperative scheduling in active objects

Author

Serbanescu, V.N. (Vlad), Boer, F.S. (Frank) de, Serbanescu, V.N. (Vlad), and Boer, F.S. (Frank) de

Abstract

Active objects interact via asynchronous messages which specify method invocations. In contrast to the run to completion mode of method execution, mechanisms for suspending the execution of a method allow an active object to schedule cooperatively its methods in a co-routine manner. In this paper, we show how cooperative scheduling can be reduced to a run to completion mode of execution. We do so by a formal translation using a guarded command language for describing the execution of method bodies.

Published
2020
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35. Locally Static, Globally Dynamic Session Types for Active Objects

Author

Reiner Hähnle and Anton W. Haubner and Eduard Kamburjan, Hähnle, Reiner, Haubner, Anton W., Kamburjan, Eduard, Reiner Hähnle and Anton W. Haubner and Eduard Kamburjan, Hähnle, Reiner, Haubner, Anton W., and Kamburjan, Eduard

Abstract

Active object languages offer an attractive trade-off between low-level, preemptive concurrency and fully distributed actors: syntactically identifiable atomic code segments and asynchronous calls are the basis of cooperative concurrency, still permitting interleaving, but nevertheless being mechanically analyzable. The challenge is to reconcile local static analysis of atomic segments with the global scheduling constraints it depends on. Here, we propose an approximate, hybrid approach; At compile-time we perform a local static analysis: later, any run not complying to a global specification is excluded via runtime checks. That specification is expressed in a type-theoretic language inspired by session types. The approach reverses the usual (first global, then local) order of analysis and, thereby, supports analysis of open distributed systems.

Published
2020
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36. Combining active object and BSP programs

Author

Leca, Pierre, Safe Composition of Autonomous applications with Large-SCALE Execution environment (SCALE), COMmunications, Réseaux, systèmes Embarqués et Distribués (Laboratoire I3S - COMRED), Laboratoire d'Informatique, Signaux, et Systèmes de Sophia Antipolis (I3S), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Laboratoire d'Informatique, Signaux, et Systèmes de Sophia Antipolis (I3S), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Université Côte d'Azur, and Françoise Baude

Subjects
Futures, [INFO.INFO-PL]Computer Science [cs]/Programming Languages [cs.PL], Modèles de programmation, Parallelism, Futurs, Task-parallelism, Actors, Benchmark, Parallélisme de tache, Active objects, Data-parallelism, BSP, Parallélisme, Programming model, Acteurs, Objets actifs, Operational semantics, Parallélisme de donnée, Sémantique opérationnelle
Abstract

This thesis presents a hybrid programming model between two parallel programming models: active objects and BSP (Bulk Synchronous Parallel). Active objects are specialized in task parallelism; they enable the execution of functionally different codes in parallel and the exchange of their results thanks to futures, which represent these results before they are available. The BSP model enables a quite different parallelism from the one provided by active objects: data-parallelism. This form of parallelism consists of cutting a task into several pieces in order to process them faster in parallel. These two specialized models enable high-level programming and provide interesting properties such as ease of programming and determinism under certain conditions. The point of combining these two models is therefore to allow the writing of programs combining task-parallelism and data-parallelism, while benefiting from the properties of the two models. This thesis studies this new BSP active object model under a theoretical aspect (with operational semantics) and a practical aspect (with a C++/MPI implementation). We also introduce a new concept of distributed future. Our distributed futures consist in unifying the concepts of futures and distributed vectors in order to represent distributed data. This allows a better integration between active objects and BSP. With our distributed futures, our BSP active objects can communicate efficiently with each other in parallel. The efficiency of these distributed futures is shown through benchmark scenarios executed on our implementation. They allow us to confirm a performance improvement of our distributed futures against classical futures.; Cette thèse présente un modèle de programmation hybride entre deux modèles de programmation parallèle : objets actifs et BSP (Bulk Synchronous Parallel). Les objets actifs sont spécialisés dans le parallélisme de tâche ; ils permettent d'exécuter du code fonctionnellement différent en parallèle, et d'échanger leurs résultats grâce à des futurs qui représentent ces résultats avant-même qu'ils soient disponibles. Le modèle BSP permet, quant à lui, un parallélisme assez différent de celui des objets actifs : un parallélisme de donnée. Ce parallélisme consiste à découper une tâche en plusieurs morceaux et de les traiter en parallèle pour aller plus vite. Ces deux modèles spécialisés, permettent une programmation haut niveau et ont des propriétés intéressantes telle que la facilité de programmation et le déterminisme sous certaines conditions. L'intérêt d'allier ces deux modèles est donc de permettre l'écriture de programmes combinant parallélisme de tâche et parallélisme de donnée, tout en bénéficiant des caractéristiques des deux modèles. Cette thèse étudie ce nouveau modèle d'objets actifs BSP sous un aspect théorique (grâce à une sémantique opérationnelle) et pratique (grâce à une implémentation en C++ avec MPI). Un nouveau concept de futurs distribués est également défini ; ils consistent à unifier les concepts de futurs et de vecteurs distribués. Cela permet une meilleure intégration entre objets actifs et BSP : grâce à eux, nos objets actifs BSP peuvent échanger entre eux efficacement en parallèle. L'efficacité de ces futurs distribués est montrée grâce à des benchmarks sur notre implémentation qui comparent les performances des futurs classiques et des futurs distribués.

Published
2020

37. Combinaison de programmes à objets actifs et BSP

Author

Leca, Pierre, Safe Composition of Autonomous applications with Large-SCALE Execution environment (SCALE), COMmunications, Réseaux, systèmes Embarqués et Distribués (Laboratoire I3S - COMRED), Laboratoire d'Informatique, Signaux, et Systèmes de Sophia Antipolis (I3S), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Laboratoire d'Informatique, Signaux, et Systèmes de Sophia Antipolis (I3S), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Université Côte d'Azur, and Françoise Baude

Subjects
Futures, [INFO.INFO-PL]Computer Science [cs]/Programming Languages [cs.PL], Modèles de programmation, Parallelism, Futurs, Task-parallelism, Actors, Benchmark, Parallélisme de tache, Active objects, Data-parallelism, BSP, Parallélisme, Programming model, Acteurs, Objets actifs, Operational semantics, Parallélisme de donnée, Sémantique opérationnelle
Abstract

This thesis presents a hybrid programming model between two parallel programming models: active objects and BSP (Bulk Synchronous Parallel). Active objects are specialized in task parallelism; they enable the execution of functionally different codes in parallel and the exchange of their results thanks to futures, which represent these results before they are available. The BSP model enables a quite different parallelism from the one provided by active objects: data-parallelism. This form of parallelism consists of cutting a task into several pieces in order to process them faster in parallel. These two specialized models enable high-level programming and provide interesting properties such as ease of programming and determinism under certain conditions. The point of combining these two models is therefore to allow the writing of programs combining task-parallelism and data-parallelism, while benefiting from the properties of the two models. This thesis studies this new BSP active object model under a theoretical aspect (with operational semantics) and a practical aspect (with a C++/MPI implementation). We also introduce a new concept of distributed future. Our distributed futures consist in unifying the concepts of futures and distributed vectors in order to represent distributed data. This allows a better integration between active objects and BSP. With our distributed futures, our BSP active objects can communicate efficiently with each other in parallel. The efficiency of these distributed futures is shown through benchmark scenarios executed on our implementation. They allow us to confirm a performance improvement of our distributed futures against classical futures.; Cette thèse présente un modèle de programmation hybride entre deux modèles de programmation parallèle : objets actifs et BSP (Bulk Synchronous Parallel). Les objets actifs sont spécialisés dans le parallélisme de tâche ; ils permettent d'exécuter du code fonctionnellement différent en parallèle, et d'échanger leurs résultats grâce à des futurs qui représentent ces résultats avant-même qu'ils soient disponibles. Le modèle BSP permet, quant à lui, un parallélisme assez différent de celui des objets actifs : un parallélisme de donnée. Ce parallélisme consiste à découper une tâche en plusieurs morceaux et de les traiter en parallèle pour aller plus vite. Ces deux modèles spécialisés, permettent une programmation haut niveau et ont des propriétés intéressantes telle que la facilité de programmation et le déterminisme sous certaines conditions. L'intérêt d'allier ces deux modèles est donc de permettre l'écriture de programmes combinant parallélisme de tâche et parallélisme de donnée, tout en bénéficiant des caractéristiques des deux modèles. Cette thèse étudie ce nouveau modèle d'objets actifs BSP sous un aspect théorique (grâce à une sémantique opérationnelle) et pratique (grâce à une implémentation en C++ avec MPI). Un nouveau concept de futurs distribués est également défini ; ils consistent à unifier les concepts de futurs et de vecteurs distribués. Cela permet une meilleure intégration entre objets actifs et BSP : grâce à eux, nos objets actifs BSP peuvent échanger entre eux efficacement en parallèle. L'efficacité de ces futurs distribués est montrée grâce à des benchmarks sur notre implémentation qui comparent les performances des futurs classiques et des futurs distribués.

Published
2020

38. On the nature of cooperative scheduling in active objects

Author

Frank S. de Boer, Vlad Serbanescu, and Centrum Wiskunde & Informatica, Amsterdam (CWI), The Netherlands

Subjects
Correctness, Computer science, Distributed computing, 020207 software engineering, Cooperative scheduling, 02 engineering and technology, Active objects, Semantics, Scheduling (computing), Guarded Command Language, Asynchronous communication, 020204 information systems, 0202 electrical engineering, electronic engineering, information engineering, Active object, Run to completion
Abstract

Active objects interact via asynchronous messages which specify method invocations. In contrast to the run to completion mode of method execution, mechanisms for suspending the execution of a method allow an active object to schedule cooperatively its methods in a co-routine manner. In this paper, we show how cooperative scheduling can be reduced to a run to completion mode of execution. We do so by a formal translation using a guarded command language for describing the execution of method bodies.

Published
2020

39. Locally Static, Globally Dynamic Session Types for Active Objects

Author

Hähnle, Reiner, Haubner, Anton W., and Kamburjan, Eduard

Subjects
Theory of computation → Object oriented constructs, Theory of computation → Distributed computing models, Active Objects, Runtime Verification, Static Verification, Session Types, Theory of computation → Type structures
Abstract

Active object languages offer an attractive trade-off between low-level, preemptive concurrency and fully distributed actors: syntactically identifiable atomic code segments and asynchronous calls are the basis of cooperative concurrency, still permitting interleaving, but nevertheless being mechanically analyzable. The challenge is to reconcile local static analysis of atomic segments with the global scheduling constraints it depends on. Here, we propose an approximate, hybrid approach; At compile-time we perform a local static analysis: later, any run not complying to a global specification is excluded via runtime checks. That specification is expressed in a type-theoretic language inspired by session types. The approach reverses the usual (first global, then local) order of analysis and, thereby, supports analysis of open distributed systems., OASIcs, Vol. 86, Recent Developments in the Design and Implementation of Programming Languages, pages 1:1-1:24

Published
2020
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40. Asynchronous Programming in the Abstract Behavioural Specification Language

Author

Azadbakht, Keyvan, Boer, F.S. de, Vink, E.P. de, Arbab, F., Bonsangue, M.M., Henrio, L., Plaat, A., Sirjani, M., and Leiden University

Subjects
preferential attachment, active objects, multi threading, software verification, concurrency, actor model, deadlock detection
Abstract

Chip manufacturers are rapidly moving towards so-called manycore chips with thousands of independent processors on the same silicon real estate. Current programming languages can only leverage the potential power by inserting code with low level concurrency constructs, sacrificing clarity. Alternatively, a programming language can integrate a thread of execution with a stable notion of identity, e.g., in active objects.Abstract Behavioural Specification (ABS) is a language for designing executable models of parallel and distributed object-oriented systems based on active objects, and is defined in terms of a formal operational semantics which enables a variety of static and dynamic analysis techniques for the ABS models.The overall goal of this thesis is to extend the asynchronous programming model and the corresponding analysis techniques in ABS.

Published
2019

41. A formal actor-based model for streaming the future

Author

Azadbakht, K. (Keyvan), Boer, F.S. (Frank) de, Bezirgiannis, N. (Nikolaos), Vink, E.P. (Erik) de, Azadbakht, K. (Keyvan), Boer, F.S. (Frank) de, Bezirgiannis, N. (Nikolaos), and Vink, E.P. (Erik) de

Abstract

Asynchronous Actor-based programming has gained increasing attention as a model of concurrency and distribution. The Abstract Behavioral Specification (ABS) language is an actor-based programming language that has been developed for both the modeling and formal analysis of distributed systems. In ABS, actors are modeled as concurrent objects that communicate by asynchronous method calls. Return values are also communicated asynchronously via return statements and so-called futures. Many modern distributed software applications require a form of continuous interaction between their components which consists of streaming data from a server to its clients. In this paper, we extend the ABS language in order to support the streaming of data. We introduce the notion of “future-based data streams” by augmenting the syntax, type system, and operational semantics of ABS. As a proof of concept, we further discuss a prototype implementation for supporting future-based data streams on top of ABS, and discuss the impact of the use of these data streams in ABS on the performance in the implementation of a distributed application for the generation of social networks.

Published
2019
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42. Rediscovering Interdisciplinarity in Contemporary Brazilian Art: The Work of Willys de Castro.

Author

da Silva, RenatoRodrigues

Subjects
*BRAZILIAN art, *POETICS, *21ST century art, *AVANT-garde (Arts), *ART woodwork
Abstract

The Active Objects series is the contribution of Brazilian artist and poet Willys de Castro (1926-1988) to Neoconcretism, which was an avant-garde movement in Rio de Janeiro from 1959 to the mid-1960s that changed the parameters of Brazilian art definitively. A typical Active Object is composed of a wooden structure covered with painted canvas that is hung on the wall like a regular painting - but the evident tri-dimensionality of the object purposefully contrasts with the flatness of its frontal surface. Thus the artist addressed the potential conflict between sculpture and painting to the benefit of a fruitful interdisciplinary practice. The reception of these works, however, is still based on Ferreira Gullar's formalist writings of the late 1950s, and does not consider Castro's poetic production, which informed the series. Based on poststructuralist theory, the article analyses his works in an attempt to understand their complex regimes of signification. [ABSTRACT FROM AUTHOR]

Published
2010
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43. A FRAMEWORK FOR ACTIVE OBJECTS IN .NET.

Author

Suciu, Dan Mircea and Cut, Alina

Subjects
OBJECT-oriented programming, COMPUTER science, COMPUTER programming, CODE reuse, OBJECT-oriented databases, DATABASE design
Abstract

Nowadays, the concern of computer science is to find new methodologies that help decomposing large programs and run them efficiently onto new parallel machines. Thus, the popularity of concurrent object-oriented programming has increased proportionally with the market requirements of concurrent and distributed systems that meet simplicity, modularity and code reusability. The purpose of this paper is to define a class library based on Active Object pattern introduced in [3], which has a high level of extensibility. Class library's main objective is to help in building concurrent object-oriented applications with a minimum effort and using a significant amount of already existing code. This approach addresses the problem of integrating concurrency with object-oriented programming and respects the principles imposed by them. In order to present the main features of our model a sample application is presented. [ABSTRACT FROM AUTHOR]

Published
2010

44. Interacting Process Classes.

Author

GOEL, ANKIT, ROYCHOUDHURY, ABHIK, and THIAGARAJAN, P. S.

Subjects
SIMULATION methods & models, SET theory, GRAPHIC methods, CONTROL theory (Engineering), CYBERNETICS, AUTOMATIC control systems
Abstract

Many reactive control systems consist of classes of active objects involving both intraclass interactions (i.e., objects belonging to the same class interacting with each other) and interclass interactions. Such reactive control systems appear in domains such as telecommunication, transportation and avionics. In this article, we propose a modeling and simulation technique for interacting process classes. Our modeling style uses standard notations to capture behavior. In particular, the control flow of a process class is captured by a labeled transition system, unit interactions between process objects are described as transactions, and the structural relations are captured via class diagrams. The key feature of our approach is that our execution semantics leads to an abstract simulation technique which involves (i) grouping together active objects into equivalence classes according their potential futures, and (ii) keeping track of the number of objects in an equivalence class rather than their identities. Our simulation strategy is both time and memory efficient and we demonstrate this on well-studied nontrivial examples of reactive systems. We also present a case study involving a weather-update controller from NASA to demonstrate the use of our simulator for debugging realistic designs. [ABSTRACT FROM AUTHOR]

Published
2009
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45. File transfer in Grid applications at deployment, execution and retrieval.

Author

Baude, Françoise, Caromel, Denis, and Leyton, Mario

Subjects
COMPUTER files, COMPUTER systems, INFORMATION storage & retrieval systems, MIDDLEWARE, COMPUTER programming
Abstract

In this article a three staged file transfer approach for the Grid is proposed. File transfer in the Grid can take place at three stages: deployment, user application execution, and retrieval (post-execution). Each stage has it's own environmental requirements, and therefore different techniques must be applied. The contributions presented in this article can be grouped in two. First, the integration of heterogeneous resource acquisition and file transfer protocols. This allows on-the-fly deployment and retrieval of files. Secondly, an asynchronous file transfer mechanism based on active objects, wait-by-necessity, and automatic continuation. The proposed file transfer model has been implemented using the ProActive middleware. ProActive provides, among others, a Grid infrastructure abstraction using deployment descriptors, and a programming model based on active objects with transparent futures. Finally, the proposed file transfer model is benchmarked and validated with a real case study: BLAST. [ABSTRACT FROM AUTHOR]

Published
2007
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46. Strong types for coordinating active objects.

Author

Puntigam, Franz

Subjects
CONCURRENT engineering, COMPUTER programming, MESSAGE processing (Telecommunication), ASYNCHRONOUS transfer mode, COMPUTER systems
Abstract

An object type is usually regarded as a contract between an object and each of its clients. However, in concurrent (and sometimes also in sequential) systems it is more useful to regard a type as a contract between an object and the set of all clients: when the object acts as a shared resource, the clients must be coordinated before sending messages to the object. Process types of active objects specify constraints on the ordering of messages. Static type checking ensures proper coordination of clients so that objects receive messages only in acceptable orderings. As presented in this article, the process type system is based on a simple computation model where active objects communicate via asynchronous message passing. Copyright © 2001 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2001
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47. Розробка мови програмування для розподілених обчислень на основі моделі акторів

Author

Ісаченко, Георгій Вадимович

Subjects
parallelism, active objects, мова програмування, асинхронні повідомлення, asynchronous messages, programming language, активний об’єкт, actor model, distributed computing, паралелізм, розподілені обчислення, горизонтальне масштабування, horizontal scaling, модель акторів
Abstract

До пояснювальної записки входять 5 розділів, 19 таблиць, 9 рисунків, а також 8 посилань на джерела інформації та додаток з програмним кодом. Загальний обсяг складає 60 сторінок. Метою дослідження є аналіз методів розподілених обчислень та спрощення способів реалізації таких обчислень. Для досягнення такої мети обрано реалізувати мову програмування на моделі акторів – моделі паралельних обчислень. Крім інтерпретатора для виконання мови також розроблено комплекс інструментів для управління розподіленими середовищами, на базі яких має виконуватися розроблена мова. У першому розділі наведено основні теоретичні відомості щодо моделі акторів, оглянуто її варіації, сучасні та історичні реалізації, а також на їх основі виведено основні функціональні вимоги до мови програмування. У другому та третьому розділі наведено опис мови програмування, способів її роботи, а також архітектурні та алгоритмічні деталі роботи комплексу. У четвертому розділі наведені тестування результату роботи та описані способи тестування комплексу у різних умовах та середовищах, а у п’ятому розділі описано спосіб його розгортання. Також до пояснювальної записки додаються графічні матеріали із схемою діаграми діяльності, схемою структурною класів програмного забезпечення та схемою використання. Explanatory note for the diploma thesis consists of 5 chapters, 19 tables, 9 images, 8 sources of information and single annex with source code. Total size is 60 pages. The purpose of the study is to analyze different methods of distributed computing and simplify implementation of those. In order to achieve this goal a new programming language is proposed and implemented. This language is based on actor computations model. In addition, some investigation and work is done over a tool to create and manage distributed environments, which will run mentioned programming language. First chapter describes general theory about actor model and variations of it. Modern industry and academic implementations are also described. All this analysis is used to write down the functional requirements of the language. Second and third chapters defines a language, along with its syntax and semantics. There is also a description of architecture that is used to implement all the system and algorithms that make it work. Fourth chapter holds notes about testing of the final product and results of those testing. Fifth chapter describes a way to deploy and set up programming language for real-world use. In addition, graphic annexes are added to the end of explanatory note. Thay contain schemes of activities, diagram of class structure and business-process diagram.

Published
2019

48. A high performance core for OSI management agents: implementation, simulation and performance evaluation

Author

Matias Júnior Rivalino

Subjects
osi network management, telecommunication management network, agent core simulation, multithreading, active objects, performance evaluation, Computer engineering. Computer hardware, TK7885-7895, Electronic computers. Computer science, QA75.5-76.95
Abstract

This article presents a proposal of a multithreaded core for an OSI/ISO management agents including its modeling, simulation and performance evaluation. The proposed model i s compared against another one (unthreaded core) which is the commonly adopted model by the most of the network management systems. All the modeling and simulation process were done at the a gent core level. Therefore the performance evaluation do not consider any effect of the communication layers, dealing with the performance of the activities related to the core of the agents applications.

Published
1999

49. Capability-Based Type Systems for Concurrency Control

Author

Castegren, Elias and Castegren, Elias

Abstract

Since the early 2000s, in order to keep up with the performance predictions of Moore's law, hardware vendors have had to turn to multi-core computers. Today, parallel hardware is everywhere, from massive server halls to the phones in our pockets. However, this parallelism does not come for free. Programs must explicitly be written to allow for concurrent execution, which adds complexity that is not present in sequential programs. In particular, if two concurrent processes share the same memory, care must be taken so that they do not overwrite each other's data. This issue of data-races is exacerbated in object-oriented languages, where shared memory in the form of aliasing is ubiquitous. Unfortunately, most mainstream programming languages were designed with sequential programming in mind, and therefore provide little or no support for handling this complexity. Even though programming abstractions like locks can be used to synchronise accesses to shared memory, the burden of using these abstractions correctly and efficiently is left to the programmer. The contribution of this thesis is programming language technology for controlling concurrency in the presence of shared memory. It is based on the concept of reference capabilities, which facilitate safe concurrent programming by restricting how memory may be accessed and shared. Reference capabilities can be used to enforce correct synchronisation when accessing shared memory, as well as to prevent unsafe sharing when using more fine-grained concurrency control, such as lock-free programming. This thesis presents the design of a capability-based type system with low annotation overhead, that can statically guarantee the absence of data-races without giving up object-oriented features like aliasing, subtyping and code reuse. The type system is formally proven safe, and has been implemented for the highly concurrent object-oriented programming language Encore., UPMARC

Published
2018

50. A Petri net based modeling of active objects and futures

Author

Boer, F.S. (Frank) de, Bravetti, M. (Mario), Lee, M.D. (Matias), Zavattaro, G. (Gianluigi), Boer, F.S. (Frank) de, Bravetti, M. (Mario), Lee, M.D. (Matias), and Zavattaro, G. (Gianluigi)

Abstract

We give two different notions of deadlock for systems based on active objects and futures. One is based on blocked objects and conforms with the classical definition of deadlock by Coffman, Jr. et al. The other one is an extended notion of deadlock based on blocked processes which is more general than the classical one. We introduce a technique to prove deadlock freedom of systems of active objects. To check deadlock freedom an abstract version of the program is translated into Petri nets. Extended deadlocks, and then also classical deadlock, can be detected via checking reachability of a distinct marking. Absence of deadlocks in the Petri net constitutes deadlock freedom of the concrete system.

Published
2018
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