22,743 research outputs found
Fuzzy Bigraphs: An Exercise in Fuzzy Communicating Agents
Bigraphs and their algebra is a model of concurrency. Fuzzy bigraphs are a
generalization of birgraphs intended to be a model of concurrency that
incorporates vagueness. More specifically, this model assumes that agents are
similar, communication is not perfect, and, in general, everything is or
happens to some degree.Comment: 11 pages, 3 figure
Reasoning about explicit resource management
We investigate the behaviour and efficiency of concurrent processes with explicit resource management.
Our study is based on a Ï-calculus variant called RÏ [4] where the only resources available are channels,
which must be explicitly allocated before they can be used and can be deallocated when no longer
required. A substructural type system guarantees the safe allocation and deallocation of channels, as well
as safe channel reuse through strong updates. In this paper we use this type system to give compositional
proof techniques for reasoning about the behaviour and efficiency of RÏ processes.peer-reviewe
A Study of Concurrency Bugs and Advanced Development Support for Actor-based Programs
The actor model is an attractive foundation for developing concurrent
applications because actors are isolated concurrent entities that communicate
through asynchronous messages and do not share state. Thereby, they avoid
concurrency bugs such as data races, but are not immune to concurrency bugs in
general. This study taxonomizes concurrency bugs in actor-based programs
reported in literature. Furthermore, it analyzes the bugs to identify the
patterns causing them as well as their observable behavior. Based on this
taxonomy, we further analyze the literature and find that current approaches to
static analysis and testing focus on communication deadlocks and message
protocol violations. However, they do not provide solutions to identify
livelocks and behavioral deadlocks. The insights obtained in this study can be
used to improve debugging support for actor-based programs with new debugging
techniques to identify the root cause of complex concurrency bugs.Comment: - Submitted for review - Removed section 6 "Research Roadmap for
Debuggers", its content was summarized in the Future Work section - Added
references for section 1, section 3, section 4.3 and section 5.1 - Updated
citation
Weaving Concurrency in eXecutable Domain-Specific Modeling Languages
International audienceThe emergence of modern concurrent systems (e.g., Cyber-Physical Systems or the Internet of Things) and highly-parallel platforms (e.g., many-core, GPGPU pipelines, and distributed platforms) calls for Domain-Specific Modeling Languages (DSMLs) where concurrency is of paramount importance. Such DSMLs are intended to propose constructs with rich concurrency semantics, which allow system designers to precisely define and analyze system behaviors. However , specifying and implementing the execution semantics of such DSMLs can be a difficult, costly and error-prone task. Most of the time the concurrency model remains implicit and ad-hoc, embedded in the underlying execution environment. The lack of an explicit concurrency model prevents: the precise definition, the variation and the complete understanding of the semantics of the DSML, the effective usage of concurrency-aware analysis techniques, and the exploitation of the concurrency model during the system refinement (e.g., during its allocation on a specific platform). In this paper, we introduce a concurrent executable metamodeling approach, which supports a modular definition of the execution semantics , including the concurrency model, the semantic rules, and a well-defined and expressive communication protocol between them. Our approach comes with a dedicated metalanguage to specify the communication protocol, and with an execution environment to simulate executable models. We illustrate and validate our approach with an implementation of fUML, and discuss the modularity and applicability of our approach
Action planning for graph transition systems
Graphs are suitable modeling formalisms for software and hardware systems involving aspects such as communication,
object orientation, concurrency, mobility and distribution. State spaces of such systems can be represented by graph transition systems, which are basically transition systems whose states and transitions represent graphs and graph morphisms. In this paper, we propose the modeling of graph transition systems in PDDL and the application of heuristic search planning for their analysis. We consider different heuristics and present experimental results
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