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18
Bisimulations in the joincalculus
 Theoretical Computer Science
, 1998
"... We propose an objectoriented calculus with internal concurrency and classbased inheritance that is built upon the join calculus. Method calls, locks, and states are handled in a uniform manner, using asynchronous messages. Classes are partial message definitions that can be combined and transforme ..."
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Cited by 50 (6 self)
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We propose an objectoriented calculus with internal concurrency and classbased inheritance that is built upon the join calculus. Method calls, locks, and states are handled in a uniform manner, using asynchronous messages. Classes are partial message definitions that can be combined and transformed. We design operators for behavioral and synchronization inheritance. We also give a type system that statically enforces basic safety properties. Our model is compatible with the JoCaml implementation
Imperative Objects and Mobile Processes
 MATH. STRUCT. COMPUT. SCI
, 1998
"... An interpretation of Abadi and Cardelli's firstorder Imperative Object Calculus into a typed picalculus is presented. The interpretation validates the subtyping relation and the typing judgements of the Object Calculus, and is computationally adequate. The proof of computational adequacy makes use ..."
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Cited by 41 (13 self)
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An interpretation of Abadi and Cardelli's firstorder Imperative Object Calculus into a typed picalculus is presented. The interpretation validates the subtyping relation and the typing judgements of the Object Calculus, and is computationally adequate. The proof of computational adequacy makes use of (a picalculus version) of ready simulation, and of a factorisation of the interpretation into a functional part and a very simple imperative part. The interpretation can be used to compare and contrast the Imperative and the Functional Object Calculi, and to prove properties about them, within a unified framework.
Compilation and Equivalence of Imperative Objects
, 1998
"... We adopt the untyped imperative object calculus of Abadi and Cardelli as a minimal setting in which to study problems of compilation and program equivalence that arise when compiling objectoriented languages. We present both a bigstep and a smallstep substitutionbased operational semantics fo ..."
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Cited by 34 (4 self)
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We adopt the untyped imperative object calculus of Abadi and Cardelli as a minimal setting in which to study problems of compilation and program equivalence that arise when compiling objectoriented languages. We present both a bigstep and a smallstep substitutionbased operational semantics for the calculus. Our rst two results are theorems asserting the equivalence of our substitutionbased semantics with a closurebased semantics like that given by Abadi and Cardelli. Our third result is a direct proof of the correctness of compilation to a stackbased abstract machine via a smallstep decompilation algorithm. Our fourth result is that contextual equivalence of objects coincides with a form of Mason and Talcott's CIU equivalence; the latter provides a tractable means of establishing operational equivalences. Finally, we prove correct an algorithm, used in our prototype compiler, for statically resolving method osets. This is the rst study of correctness of an objectoriented abstract machine, and of operational equivalence for the imperative object calculus.
Objects as Mobile Processes
 RESEARCH SERIES RS9638, BRICS
, 1996
"... The object calculus of Abadi and Cardelli [AC96, AC94b, AC94a] is intended as model of central aspects of objectoriented programming languages. In this paper we encode the object calculus in the asynchronous picalculus without matching and investigate the properties of our encoding. ..."
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Cited by 11 (4 self)
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The object calculus of Abadi and Cardelli [AC96, AC94b, AC94a] is intended as model of central aspects of objectoriented programming languages. In this paper we encode the object calculus in the asynchronous picalculus without matching and investigate the properties of our encoding.
Verifiable and Executable Logic Specifications of Concurrent Objects in L_pi
, 1998
"... We present the coreL_pi fragment of L_pi and its program logic. We illustrate the adequacy of L_pi as a metalanguage for jointly defining operational semantics and program logics of languages with concurrent and logic features, considering the case of a specification logic for concurrent objects a ..."
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Cited by 9 (0 self)
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We present the coreL_pi fragment of L_pi and its program logic. We illustrate the adequacy of L_pi as a metalanguage for jointly defining operational semantics and program logics of languages with concurrent and logic features, considering the case of a specification logic for concurrent objects addressing mobile features like creation of objects and channels in a simple way. Specifications are executable by a translation that assigns to every specification a model in the form of a coreL_pi program. We also illustrate the usefulness of this framework in reasoning about systems and their components.
Migration = Cloning ; Aliasing (preliminary version)
"... In Obliq, a lexically scoped, distributed, objectbased programming language, object migration was suggested as creating a (remote) copy of an object's state at the target site, followed by turning the (local) object itself into an alias, also called surrogate, for the just created remote copy. Ther ..."
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Cited by 7 (7 self)
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In Obliq, a lexically scoped, distributed, objectbased programming language, object migration was suggested as creating a (remote) copy of an object's state at the target site, followed by turning the (local) object itself into an alias, also called surrogate, for the just created remote copy. There is no proof that object migration in Obliq is safe in any sense. We consider the creation of object surrogates as an abstraction of the abovementioned style of migration. We introduce Øjeblik, a distributionfree subset of Obliq, and provide two formal semantics, one in an intuitive configuration style, the other in terms of πcalculus. The intuitive semantics shows why surrogation is neither safe in Obliq, nor can it be so in full generality in Repliq (a repaired Obliq). The πcalculus semantics allows us to prove that surrogation in Øjeblik is safe for certain wellidentified cases, thus suggesting that migration in Repliq may be safe, accordingly.
The name discipline of uniform receptiveness (Extended Abstract)
 In Proceedings of ICALP'97
, 1997
"... this paper, we study the situation in which certain names are uniformly receptive. A name x is receptive in a process P if at any time P is able of offering an input at x (at least as long as there are processes that could send messages at x). The receptiveness of x is uniform if all inputs at x hav ..."
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Cited by 5 (0 self)
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this paper, we study the situation in which certain names are uniformly receptive. A name x is receptive in a process P if at any time P is able of offering an input at x (at least as long as there are processes that could send messages at x). The receptiveness of x is uniform if all inputs at x have the same continuation. Receptiveness ensures that any message sent at x can be immediately processed; unformity ensures that there is a unique way in which a message at x may be processed (that is, the input end of x is "functional").
Mobile Objects as Mobile Processes
, 2001
"... this paper, we rewrite our modified semantics of jeblik in terms of the #calculus, and we use it to formally prove the correctness of object surrogation, the abstraction of object migration in jeblik. Key Words: #calculus, Objects, Migration 1. ..."
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Cited by 3 (1 self)
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this paper, we rewrite our modified semantics of jeblik in terms of the #calculus, and we use it to formally prove the correctness of object surrogation, the abstraction of object migration in jeblik. Key Words: #calculus, Objects, Migration 1.
Responsive Bisimulation
 In Proceedings of the 2nd IFIP InternationalConference on Theoretical Computer Science
, 2002
"... This paper introduces the responsive bisimulation, which treats local delays of incoming messages the same as external delays, as long as potential interference by competing receptors is avoided. By this bisimulation, the calculus process , representing a lock with a message receptor , is ..."
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Cited by 2 (0 self)
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This paper introduces the responsive bisimulation, which treats local delays of incoming messages the same as external delays, as long as potential interference by competing receptors is avoided. By this bisimulation, the calculus process , representing a lock with a message receptor , is equivalent to the 22824 ; the first process will delay messages externally, the second locally. Existing bisimulations distinguish between these processes. The responsive bisimulation is a congruence for the family of processes which model objects. It is useful for studying compositional synchronisation in such models. 1.
An Interpretation of Typed Concurrent Objects in the Blue Calculus
 In Proceedings of the Conference on Empirical Methods in Natural Language Pr ocessing
, 1999
"... We propose an interpretation of a typed concurrent calculus of objects (conc&) based on the model of Abadi and Cardelli's imperative object calculus. The target of our interpretation is a version of the blue calculus, a variant of the picalculus that directly contains the lambdacalculus, with reco ..."
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Cited by 1 (0 self)
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We propose an interpretation of a typed concurrent calculus of objects (conc&) based on the model of Abadi and Cardelli's imperative object calculus. The target of our interpretation is a version of the blue calculus, a variant of the picalculus that directly contains the lambdacalculus, with record and firstorder types. We show that reduction and type judgements can be derived in a rather simple and natural way, and that our encoding can be extended to "selftypes" and synchronisation primitives. We also prove some equational laws on objects.