### Abstract

Introduction.
Scheduling Iheory has a rich and long hislOry. In add ilion. process algebras have
been S1udied as a formal Iheory of syslem design and verificalion since Ihe early
19805. However, these two separate worlds have not been connected until recent
years and Ihe conneclion is nol yel complele. In olher words, using Ihe models
and algorithms of scheduling Iheory in a process algebraic design is S1ill involved
wilh many theoretical and praclical complicalions. In this chapter. building upon
previous attempts in Ihis direction, we propose a process algebra. called PARS for
Process Algebra with Resources and Schedulers, for the design of scheduled realtime
systems. Previous attempts to incorporate scheduling algorithms in process
algebra either did not have an explicit notion of schedulers [5 , 15 ,16) (thus, coding
the scheduling policy in the process specification) or scheduling is treated for
restricled cases thai only support single-processor scheduling [6,12).
Our approach to modeling scheduled sYSIems is depicled in Figure 10. 1. In this
approach, process specificalion (including aspeclS such as causal relalions of actions,
Iheir liming and resource requiremenlS) is separated from Ihe specificalion of
schedulers. Then one can apply schedulers to processes to oblain scheduled systems
and further compose scheduled systems together. A distinguishing feature of our
process algebra is the possibility of specifying schedulers as process terms (similar
to resource-consuming processes). Another advantage of the proposed approach
is the separation between process specification and scheduler specification that provides
a separation of concerns. allows for specifying generic scheduling strategies
and makes it possible to apply schedulers to systems at different levels of abstraction.
Common to most process algebraic frameworks for resources, the proposed
framework provides the possibility of extending standard schedulability analysis to
the formal verification process.

Original language | English |
---|---|

Title of host publication | Process Algebra for Parallel and Distributed Processing |

Editors | M. Alexander, W. Gardner |

Publisher | Chapman & Hall |

Pages | 331-358 |

ISBN (Print) | 978-1-4200-6486-5 |

Publication status | Published - 2008 |

### Publication series

Name | CRC Computational Science Series |
---|---|

Volume | 2 |

## Fingerprint Dive into the research topics of 'PARS : a process algebraic approach to resources and schedulers'. Together they form a unique fingerprint.

## Cite this

Mousavi, M. R., Reniers, M. A., Basten, T., & Chaudron, M. R. V. (2008). PARS : a process algebraic approach to resources and schedulers. In M. Alexander, & W. Gardner (Eds.),

*Process Algebra for Parallel and Distributed Processing*(pp. 331-358). (CRC Computational Science Series; Vol. 2). Chapman & Hall.