Optimal wait-free clock synchronization protocol on a shared-memory multi-processor system

  • Michiko Inoue
  • Sen Moriya
  • Toshimitsu Masuzawa
  • Hideo Fujiwara
Contributed Papers
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1320)


We consider wait-free clock synchronization protocols on an in-phase shared-memory multi-processor system. A wait-free clock synchronization protocol guarantees that, for a fixed k, local clocks of processors which have been working consecutively for at least k pulses are synchronized. Such k is called synchronization time. The best previous result with regard to the synchronization time is O(n2), where n is the number of processors. In this paper, we present a wait-free synchronization protocol with synchronization time O(n), and also show that this synchronization time is asymptotically optimal.


clock-synchronization shared-memory multi-processor system wait-freedom fault-tolerance napping fault 


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  1. 1.
    L. Lamport and P. Melliar-Smith: “Synchronizing clocks in the presence of faults”, Journal of the ACM, 32, 1, pp. 1–36 (1985).CrossRefGoogle Scholar
  2. 2.
    S. Dolev, J. Halpern and H. Strong: “On the possibility and impossibility of achieving clock synchronization”, Journal of Computer Systems Science, 32, 2, pp. 230–250 (1986).CrossRefGoogle Scholar
  3. 3.
    S. Mahaney and F. Schneider: “Inexact agreement: Accuracy, precision and graceful degradation”, Proceedings of the 4th ACM Symposium on Principles of Distributed Computing, pp. 237–249 (1985).Google Scholar
  4. 4.
    T. Srikanth and S. Toueg: “Optimal clock synchronization”, Journal of the ACM, 34, 3, pp. 626–645 (1987).CrossRefGoogle Scholar
  5. 5.
    J. Welch and N. Lynch: “A new fault-tolerant algorithm for clock synchronization”, Information and Computation, 77, 1, pp. 1–36 (1988).CrossRefGoogle Scholar
  6. 6.
    J. Halpern, B. Simons, R. Strong and D. Dolev: “Fault-tolerant clock synchronization”, Proceedings of the 3rd ACM Symposium on Principles of Distributed Computing, pp. 89–102 (1984).Google Scholar
  7. 7.
    S. Dolev and J.L.Welch: “Self-stabilizing clock synchronization in the presence of byzantine faults”, Proceedings of the Second Workshop on Self-Stabilizing Systems, pp. 9.1–9.12 (1995).Google Scholar
  8. 8.
    M. Gouda and T. Herman: “Stabilizing unison”, Information Processing Letters, 35, pp. 171–175 (1990).CrossRefMathSciNetGoogle Scholar
  9. 9.
    A. Arora, S. Dolev and M. Gouda: “Maintaining digital clocks in step”, Parallel Processing Letters, 1, 1, pp. 11–8 (1991).CrossRefGoogle Scholar
  10. 10.
    A. S. Gopal and K. J. Perry: “Unifying self-stabilization and fault-tolerance”, Proceeding of the 12th ACM Symposium on Principles on Distributed Computing, pp. 195–206 (1993).Google Scholar
  11. 11.
    S. Dolev: “Possible and impossible self-stabilizing digital clock synchronization in general graphs”, Technical Report TR 96-06, Department of Mathematics and Computer Science. Ben-Gurion University (1996).Google Scholar
  12. 12.
    S. Dolev and J. Welch: “Wait-free clock synchronization”, Proceedings of the 12th ACM Symposium on Principles of Distributed Computing, pp. 97–108 (1993).Google Scholar
  13. 13.
    M. Papatriantafilou and P. Tsigas: “On self-stabilizing wait-free clock synchronization”, Proceedings of the 4th Scandinavian Workshop on Algorithm Theory (LNCS 824), pp. 267–277 (1994).Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • Michiko Inoue
    • 1
  • Sen Moriya
    • 1
  • Toshimitsu Masuzawa
    • 1
  • Hideo Fujiwara
    • 1
  1. 1.Nara Institute of Science and Technology (NAIST)Graduate School of Information ScienceIkomaJapan

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