Mobile processes with local clocks

Abstract

We propose a structural operational semantics that expresses temporal aspects of mobile and distributed systems, each sequential component of which has its local clock. Since the run-time support of a programming language implements the operations of the language via some lower-level routines, the same action, put in different contexts, may have different durations. Also the network topology affects these durations, typically when messages are exchanged. We model this through a transition system labelled by actions and their costs, in a discrete time. Then, we define two performance preordings that say when the execution of a process is faster than that of another. The first preorder is similar to those presented in the literature, while the second refines it in that it considers a process faster than another if it is such from some point onwards of its execution. Finally, as an example we compare the performance of a conventional uniprocessor architecture with a prefetch pipeline architecture

Infinite Computation, Co-induction and Computational Logic

“…The extension to time is helpful in modeling controller processes that control physical devices where a notion of real-time is important [25]. Several extensions of π-calculus with time have been proposed to overcome this problem (e.g., [5]); all these approaches discretize time rather than represent it faithfully as a continuous quantity.…”

Timed High-Order p Calculus and Multi-resolution Time Constraints

“…In his time calculus, every behavior's execution is instantaneous and the lapse time can be expressed by timer operator. But there are such problems in document [7] and document [8] . The first problem is an assumption that we foreknow the absolute time of all system behavior happened.…”

“…Document [7] extended the label from labeled transition system by introducing the concept of proof term for the related work of extending calculus. On the basis of this, that document also defines time-operating semantics of calculus which is non-time good conformation and using the mode of urgent synchronization.…”