DIKU IT-C RUC

COPLAS

Copenhagen Programming Language Seminar


Toward a Grainless Semantics for Shared-Variable Concurrency

John C. Reynolds
Queen Mary, University of London Imperial College Carnegie Mellon University

December 14th, 14:00 - 15:00
IT University, room: 4A14

Abstract:
Conventional semantics for shared-variable concurrency suffers from the "grain of time" problem, i.e., the necessity of specifying a default level of atomicity.
We propose a semantics that avoids such a choice by regarding all interference that is not controlled by explicit synchronization as catastrophic.

It is based on three principles:
- Operations have duration and can overlap one another during execution.
- If two overlapping operations touch the same location, the meaning of the program execution is "wrong".
- If, from a given starting state, execution of a program can give "wrong", then no other possibilities need be considered.

In our current approach, instead of trace sets, we use trace trees, in which we separate nondeterminism and branching.


Scientific host: Lars Birkedal Administrative host:Renée Korver Michan. All are welcome.
The Copenhagen Programming Language Seminar (COPLAS) is a collaboration between DIKU, ITU and RUC.
COPLAS is sponsored by the FIRST Graduate School.
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For more information about COPLAS, see http://www.coplas.org