Abstract
Priority is a frequently used feature of many computational systems. In this paper we study the expressiveness of two process algebras enriched with different priority mechanisms. In particular, we consider a finite (i.e. recursion-free) fragment of asynchronous CCS with global priority (FAP, for short) and Phillips’ CPG (CCS with local priority), and we contrast their expressive power with that of two non-prioritised calculi, namely the π-calculus and its broadcast-based version, called bπ. We prove, by means of leader-election-based separation results, that there exists no encoding of FAP into π-Calculus or CPG, under certain conditions. Moreover, we single out another problem in distributed computing, we call the last man standing problem (LMS for short), that better reveals the gap between the two prioritised calculi above and the two non prioritised ones, by proving that there exists no parallel-preserving encoding of the prioritised calculi into the non-prioritised calculi retaining any sincere (complete but partially correct, i.e., admitting divergence or premature termination) semantics.
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References
Baeten, J.C.M., Bergstra, J.A., Klop, J.W.: Ready-trace semantics for concrete process algebra with the priority operator. Comput. J. 30(6), 498–506 (1987)
Camilleri, J., Winskel, G.: Ccs with priority choice. Inf. Comput. 116(1), 26–37 (1995)
Cleaveland, R., Hennessy, M.: Priorities in process algebras. Inf. Comput. 87(1/2), 58–77 (1990)
Cleaveland, R., Lüttgen, G., Natarajan, V.: Priority in process algebra. In: Bergstra, J., Ponse, A., Smolka, S. (eds.) Handbook of Process Algebra, pp. 711–765. Elsevier, Amsterdam (2001)
Phillips, I.: Ccs with priority guards. In: Larsen, K.G., Nielsen, M. (eds.) CONCUR 2001. LNCS, vol. 2154, pp. 305–320. Springer, Heidelberg (2001)
Bernardo, M., Gorrieri, R.: Extended markovian process algebra. In: Sassone, V., Montanari, U. (eds.) CONCUR 1996. LNCS, vol. 1119, pp. 315–330. Springer, Heidelberg (1996)
Hermanns, H.: Interactive Markov Chains: The Quest for Quantified Quality. In: Hermanns, H. (ed.) Interactive Markov Chains. LNCS, vol. 2428, Springer, Heidelberg (2002)
Bravetti, M., Gorrieri, R.: The theory of interactive generalized semi-markov processes. Theor. Comput. Sci. 282(1), 5–32 (2002)
Bernardo, M., Gorrieri, R.: A tutorial on empa: A theory of concurrent processes with nondeterminism, priorities, probabilities and time. Theor. Comput. Sci. 202(1-2), 1–54 (1998)
Baeten, J., Bergstra, J., Klop, J.: Syntax and defining equations for an interrupt mechanism in process algebra. Fundamenta Informaticae IX(2), 127–168 (1986)
Milner, R.: A Calculus of Communication Systems. LNCS, vol. 92. Springer, Heidelberg (1980)
Milner, R., Parrow, J., Walker, D.: A calculus of mobile processes, i. Inf. Comput. 100(1), 1–40 (1992)
Milner, R., Parrow, J., Walker, D.: A calculus of mobile processes, ii. Inf. Comput. 100(1), 41–77 (1992)
Ene, C., Muntean, T.: Expressiveness of point-to-point versus broadcast communications. In: Ciobanu, G., Păun, G. (eds.) FCT 1999. LNCS, vol. 1684, pp. 258–268. Springer, Heidelberg (1999)
Bougé, L.: On the existence of symmetric algorithms to find leaders in networks of communicating sequential processes. Acta Inf. 25(2), 179–201 (1988)
Palamidessi, C.: Comparing the expressive power of the synchronous and asynchronous pi-calculi. Mathematical Structures in Computer Science 13(5), 685–719 (2003)
Phillips, I.: Ccs with priority guards. Available at http://wwwhomes.doc.ic.ac.uk/~iccp/papers/ccspgfullrevised.pdf
Milner, R.: The polyadic pi-calculus: a tutorial. In: Bauer, F.L., Brauer, W., Schwichtenberg, H. (eds.) Logic and Algebra of Specification, pp. 203–246. Springer, Heidelberg (1993)
Milner, R.: Communicating and mobile systems: the π-calculus. Cambridge University Press, New York (1999)
Nestmann, U.: What is a “good” encoding of guarded choice? Inf. Comput. 156(1-2), 287–319 (2000)
Palamidessi, C., Herescu, O.M.: A randomized encoding of the pi-calculus with mixed choice. Theor. Comput. Sci. 335(2-3), 373–404 (2005)
Cardelli, L., Gordon, A.D.: Mobile ambients. In: Nivat, M. (ed.) ETAPS 1998 and FOSSACS 1998. LNCS, vol. 1378, pp. 140–155. Springer, Heidelberg (1998)
Bravetti, M., Gorrieri, R., Lucchi, R., Zavattaro, G.: Quantitative information in the tuple space coordination model. Theor. Comput. Sci. 346(1), 28–57 (2005)
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Versari, C., Busi, N., Gorrieri, R. (2007). On the Expressive Power of Global and Local Priority in Process Calculi. In: Caires, L., Vasconcelos, V.T. (eds) CONCUR 2007 – Concurrency Theory. CONCUR 2007. Lecture Notes in Computer Science, vol 4703. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-74407-8_17
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DOI: https://doi.org/10.1007/978-3-540-74407-8_17
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