BIB-VERSION:: CS-TR-v2.0
          ID:: STAN//CS-TN-96-35
       ENTRY:: June 10, 1996
ORGANIZATION:: Stanford University, Department of Computer Science
       TITLE:: A Calculus for Concurrent Objects
        TYPE:: Technical Note
      AUTHOR:: DiBlasio, Paolo
      AUTHOR:: Fisher, Kathleen
        DATE:: June 1996
       PAGES:: 22
    ABSTRACT:: This paper presents an imperative and concurrent extension of
               the functional object-oriented calculus described in [FHM94].
               It belongs to the family of so-called prototype-based
               object-oriented languages, in which objects are created from
               existing ones via the inheritance primitives of object
               extension and method override. Concurrency is introduced
               through the identification of objects and processes. To our
               knowledge, the resulting calculus is the first concurrent
               object calculus to be studied. We define an operational
               semantics for the calculus via a transition relation between
               configurations, which represent snapshots of the run-time
               system. Our static analysis includes a type inference system,
               which statically detects message-not-understood errors, and
               an effect system, which guarantees that synchronization code,
               specified via guards, is side-effect free. We present a
               subject reduction theorem, modified to account for imperative
               and concurrent features, and type and effect soundness
               theorems.
       NOTES:: [Adminitrivia V1/Prg/19960610]
         END:: STAN//CS-TN-96-35