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ZeroSafe Nets: Comparing the Collective and Individual Token Approaches
"... The main feature of zerosafe nets is a primitive notion of transition synchronization. To this aim, besides ordinary places, called stable places, zerosafe nets are equipped with zero places, which in an observable marking cannot contain any token. This yields the notion of transaction: a basic ..."
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Cited by 38 (20 self)
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The main feature of zerosafe nets is a primitive notion of transition synchronization. To this aim, besides ordinary places, called stable places, zerosafe nets are equipped with zero places, which in an observable marking cannot contain any token. This yields the notion of transaction: a basic atomic computation, which may use zero tokens as triggers, but defines an evolution between observable markings only. The abstract counterpart of a generic zerosafe net B consists of an ordinary P/T net whose places are the stable places of B, and whose transitions represent the transactions of B. The two nets offer both the refined and the abstract model of the same system, where the former can be much smaller than the latter, because of the transition synchronization mechanism. Depending on the chosen approach  collective vs individual token philosophy  two notions of transaction may be defined, each leading to different operational and abstract models. Their comparison is fully dis...
Orchestrating Transactions in Join Calculus
, 2002
"... We discuss the principles of distributed transactions, then we define an operational model which meets the basic requirements and we give a prototyping implementation for it in joincalculus. In particular, our model: (1) extends BizTalk's short transactions; (2) it exploits an original commit alg ..."
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Cited by 34 (12 self)
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We discuss the principles of distributed transactions, then we define an operational model which meets the basic requirements and we give a prototyping implementation for it in joincalculus. In particular, our model: (1) extends BizTalk's short transactions; (2) it exploits an original commit algorithm, which is distributed; (3) it can deal with dynamically changing communication topology; (4) it is almost languageindependent. In fact, the model is simply based on a twolevel classification of resources, which should be easily conveyed to distributed calculi and languages, providing them with a powerful transactional mechanism.
Graph Rewriting, Constraint Solving and Tiles for Coordinating Distributed Systems
 Applied Categorical Structures
, 1999
"... . In this paper we describe an approach to model the dynamics of distributed systems. For distributed systems we mean systems consisting of concurrent processes communicating via shared ports and posing certain synchronization requirements, via the ports, to the adjacent processes. The basic idea is ..."
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Cited by 17 (14 self)
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. In this paper we describe an approach to model the dynamics of distributed systems. For distributed systems we mean systems consisting of concurrent processes communicating via shared ports and posing certain synchronization requirements, via the ports, to the adjacent processes. The basic idea is to use graphs to represent states of such systems, and graph rewriting to represent their evolution. The kind of graph rewriting we use is based on simple contextfree productions which are however combined by means of a synchronization mechanism. This allows for a good level of expressivity in the system without sacrifying full distribution. To formally model this kind of graph rewriting, however, we do not adopt the classical graph rewriting style but a more general framework, called the tile model, which allows for a clear separation between sequential rewriting and synchronization. Then, since the problem of satisfying the synchronization requirements may be a complex combinatorial pro...
ZeroSafe Nets: The Individual Token Approach
 Proceedings WADT'97, 12th workshop on Recent Trends in Algebraic Development Techniques, volume 1376 of Lect. Notes in Comput. Sci
, 1998
"... In this paper we provide both an operational and an abstract concurrent semantics for zerosafe nets under the individual token philosophy. The main feature of zerosafe nets is a primitive notion of transition synchronization. Besides ordinary places, called stable places, zerosafe nets come equip ..."
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Cited by 13 (13 self)
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In this paper we provide both an operational and an abstract concurrent semantics for zerosafe nets under the individual token philosophy. The main feature of zerosafe nets is a primitive notion of transition synchronization. Besides ordinary places, called stable places, zerosafe nets come equipped with zero places, which are empty in any stable marking. Connected transactions represent basic atomic computations of the system between stable markings. They must satisfy two main requirements: 1) to model interacting activities which cannot be decomposed into disjoint subactivities, and 2) not to consume stable tokens which were generated in the same transaction. Zero tokens acts as triggers for the firings of the transitions which compose the transaction. The abstract counterpart of a zerosafe net consists of a P/T net where each transition locates a distinguished transaction. In the second part of the paper, following the Petri nets are monoids approach, we make use of catego...
Executable Tile Specifications for Process Calculi
, 1999
"... . Tile logic extends rewriting logic by taking into account sideeffects and rewriting synchronization. These aspects are very important when we model process calculi, because they allow us to express the dynamic interaction between processes and "the rest of the world". Since rewriting logic is the ..."
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Cited by 13 (10 self)
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. Tile logic extends rewriting logic by taking into account sideeffects and rewriting synchronization. These aspects are very important when we model process calculi, because they allow us to express the dynamic interaction between processes and "the rest of the world". Since rewriting logic is the semantic basis of several language implementation efforts, an executable specification of tile systems can be obtained by mapping tile logic back into rewriting logic, in a conservative way. However, a correct rewriting implementation of tile logic requires the development of a metalayer to control rewritings, i.e., to discard computations that do not correspond to any deduction in tile logic. We show how such methodology can be applied to term tile systems that cover and extend a wideclass of SOS formats for the specification of process calculi. The wellknown casestudy of full CCS, where the term tile format is needed to deal with recursion (in the form of the replicator operator), is di...
Symmetric and Cartesian Double Categories as a Semantic Framework for Tile Logic
, 1995
"... this paper we discuss the lifting of these auxiliary structures to double categories. We notice that the internal construction of double categories produces a pathological asymmetric notion of natural transformation, which is fully exploited in one dimension only (e.g., for configurations or for eff ..."
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Cited by 6 (5 self)
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this paper we discuss the lifting of these auxiliary structures to double categories. We notice that the internal construction of double categories produces a pathological asymmetric notion of natural transformation, which is fully exploited in one dimension only (e.g., for configurations or for effects, but not for both). Following Ehresmann (1963), we overcome this biased definition, introducing the notion of generalized natural transformation between four
Zerosafe net models for transactions in linda
 Proc. of ConCoord 2001
, 2001
"... Zerosafe nets are a variation of Petri nets, where transactions can be suitably modeled. The idea is to distinguish between stable places (whose markings define observable states) and zerosafe places (where tokens can only be temporarily allocated, defining hidden states): Transactions must start ..."
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Cited by 3 (3 self)
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Zerosafe nets are a variation of Petri nets, where transactions can be suitably modeled. The idea is to distinguish between stable places (whose markings define observable states) and zerosafe places (where tokens can only be temporarily allocated, defining hidden states): Transactions must start and end in observable states. We propose an extension of the coordination language Linda, called TraLinda, where a few basic primitives for expressing transactions are introduced by means of different typing of tuples. By exploiting previous results of Busi, Gorrieri and Zavattaro on the net modeling of Lindalike languages, we define a concurrent operational semantics based on zerosafe nets for TraLinda, where the typing of tuples reflects evidently on the distinction between stable and zerosafe places.
Algebra of Networks  Modeling simple networks, as well as complex interactive systems
 In: Proof and SystemReliability, Proc. Marktoberdorf Summer School 2001, Kluwer (2002), 4978. A., Sofronia A., Stefanescu G.: Highlevel Structured Interactive
"... The rst part of the paper contains an overview of Network Algebra (NA) book [35]. The second part introduces nite interactive systems as an abstract mathematical model of agents' behaviour and their interaction. ..."
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Cited by 2 (2 self)
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The rst part of the paper contains an overview of Network Algebra (NA) book [35]. The second part introduces nite interactive systems as an abstract mathematical model of agents' behaviour and their interaction.
Can Actors and πAgents Live Together?
"... The syntax and semantics of actors and agents is first defined separately, using a uniform, "unbiased" approach. New coordination primitives are the added to the union of the two calculi which allow actors and agents to cooperate. ..."
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Cited by 1 (1 self)
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The syntax and semantics of actors and agents is first defined separately, using a uniform, "unbiased" approach. New coordination primitives are the added to the union of the two calculi which allow actors and agents to cooperate.