2026-07-23T22:06:54Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:14813 2024-03-06T10:54:54Z ddc:004 open_access

Wait-Free CAS-Based Algorithms: The Burden of the Past Bédin, Denis Lépine, François Mostéfaoui, Achour Perez, Damien Perrin, Matthieu Compare-And-Swap Concurrent Object Infinite arrival model Linearizability Memory complexity Multi-Threaded Systems Shared-Memory Universality Wait-freedom Herlihy proved that CAS is universal in the classical computing system model composed of an a priori known number of processes. This means that CAS can implement, together with reads and writes, any object with a sequential specification. For this, he proposed the first universal construction capable of emulating any data structure. It has recently been proved that CAS is still universal in the infinite arrival computing model, a model where any number of processes can be created on the fly (e.g. multi-threaded systems). In this paper, we prove that CAS does not allow to implement wait-free and linearizable visible objects in the infinite model with a space complexity bounded by the number of active processes (i.e. ones that have operations in progress on this object). This paper also shows that this lower bound is tight, in the sense that this dependency can be made as low as desired (e.g. logarithmic) by proposing a wait-free and linearizable universal construction, using the compare-and-swap operation, whose space complexity in the number of ever issued operations is defined by a parameter that can be linked to any unbounded function. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Denis Bédin and François Lépine and Achour Mostéfaoui and Damien Perez and Matthieu Perrin 2021 Is Part Of LIPIcs, Volume 209, 35th International Symposium on Distributed Computing (DISC 2021) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.DISC.2021.11 urn:nbn:de:0030-drops-148131 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.DISC.2021.11 eng https://creativecommons.org/licenses/by/4.0/legalcode