Fast, long-lived renaming improved and simplified

Abstract

In the long-lived M-renaming problem, N processes repeatedly acquire and release names ranging over {0,..., M−1}, where M < N. It is assumed that at most k processes concurrently request or hold names. Efficient solutions to the long-lived renaming problem can be used to improve the performance of applications in which processes repeatedly perform computations whose time complexity depends on the size of the name space containing the processes that participate concurrently. In this paper, we consider wait-free solutions to the long-lived M-renaming problem that use only read and write instructions in an asynchronous, shared-memory multiprocessor. A solution to long-lived renaming is fast if the time complexity of acquiring and releasing a name once is independent of N. We present a new fast, long-lived (k(k + 1)/2)-renaming algorithm that significantly improves upon the time and space complexity of similar previous algorithms, while providing a much simpler solution. We also show for the first time that fast, long-lived (2k − 1)-renaming can be implemented with reads and writes. This result is optimal with respect to the size of the name space.

This work was carried out while the first author was a graduate student at The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, and was supported in part by NSF Contract CCR 9216421, by a Young Investigator Award from the U.S. Army Research Office, grant number DAAH04-95-1-0323, and by a UNC Alumni Fellowship.