School of Computing

Communicating Mobile Processes

F.R.M. Barnes and P.H. Welch

In I. East, J. Martin, P. Welch, D. Duce, and M. Green, editors, Communicating Process Architectures 2004, volume 62 of Concurrent Systems Engineering Series, pages 182-196, Amsterdam, The Netherlands, September 2004. IOS Press.


This paper presents a new model for mobile processes in occam-pi. A process, embedded anywhere in a dynamically evolving network, may suspend itself mid-execution, be safely disconnected from its local environment, moved (by communication along a channel), reconnected to a new environment and reactivated. Upon reactivation, the process resumes execution from the same state (i.e. data values and code positions) it held when it suspended. Its view of its environment is unchanged, since that is abstracted by its synchronisation (e.g. channels and barriers) interface and that remains constant. The environment behind that interface will (usually) be completely different. The mobile process itself may contain any number of levels of dynamic sub-network. This model is simpler and, in some ways, more powerful than our earlier proposal, which required a process to terminate before it could be moved. Its formal semantics and implementation, however, throw up extra challenges. We present details and performance of an initial implementation.

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Bibtex Record

author = {F.R.M. Barnes and P.H. Welch},
title = {{Communicating Mobile Processes}},
month = {September},
year = {2004},
pages = {182-196},
keywords = {determinacy analysis, Craig interpolants},
note = {},
doi = {},
url = {},
    publication_type = {inproceedings},
    submission_id = {975_1095474793},
    ISBN = {1-58603-381-6},
    booktitle = {Communicating Process Architectures 2004},
    editor = {I. East and J. Martin and P. Welch and D. Duce and M. Green},
    volume = {62},
    series = {Concurrent Systems Engineering Series},
    address = {Amsterdam, The Netherlands},
    publisher = {IOS Press},
    ISSN = {1383-7575},
    refereed = {yes},

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