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Correctness Statement

Write a server that schedules some resource among C clients such that no more than R clients operate on it at the same time.

forall C, R:

forall pc:

   System_C,R(pc) =>

      always

         and

            R >= number i in [1,C]: pc_i = resource

            forall i in [1,C]: (pc_i = request =>

               eventually pc_i = resource)

System parameters.

Client states (program counters).

System.

Specification.

Safety: no more than R processes use resource.

Progress: every requesting process gets resource.

Goal for the design of the system.

Author: Wolfgang Schreiner
Last Modification: April 22, 1999