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Abstract

JavaSpaces is a coordination middleware for distributed Java programming recently proposed by Sun Microsystems. It is inspired by the Linda coordination model: processes interact via the output (write), consumption (take), test for presence (read) and the test for absence (takeIfExists and readIfExists) of data inside a shared repository. Three are the most interesting new features introduced by JavaSpaces. The first one is an event notification mechanism (notify): a process can register interest in the incoming arrivals of a particular kind of data, and then receive communication of the occurrence of these events. The second feature is the so-called distributed leasing: at the moment a client outputs a tuple, it also declares its required lifetime (that the server may satisfy only partially). The third feature is a timeout on the blocking operation of input: if no instance is found before the timeout expires, then the operation fails and terminates. We present a structured operational semantics for a process algebra featuring these coordination primitives. This abstract semantics is used to clarify possible ambiguities of the informal definitions of JavaSpaces, to discuss possible implementation choices and to compare the expressive power of the new primitives. Interestingly enough, many subtle phenomena occur, some of which might lead to reconsider the actual choice of primitives.

Keywords

Operational Semantic Label Transition System Event Notification Basic Time Interval Outgoing Transition 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© IFIP International Federation for Information Processing 2000

Authors and Affiliations

  • Nadia Busi
    • 1
  • Roberto Gorrieri
    • 1
  • Gianluigi Zavattaro
    • 1
  1. 1.Dipartimento di Scienze dell’InformazioneUniversità di BolognaBolognaItaly

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