2026-07-23T00:25:37Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:8970 2024-03-12T12:02:07Z ddc:004 open_access

Using Lock Servers to Scale Real-Time Locking Protocols: Chasing Ever-Increasing Core Counts (Artifact) Nemitz, Catherine E. Amert, Tanya Anderson, James H. multiprocess locking protocols nested locks priority-inversion blocking reader/writer locks real-time locking protocols During the past decade, parallelism-related issues have been at the forefront of real-time systems research due to the advent of multicore technologies. In the coming years, such issues will loom ever larger due to increasing core counts. Having more cores means a greater potential exists for platform capacity loss when the available parallelism cannot be fully exploited. In this work, such capacity loss is considered in the context of real-time locking protocols. In this context, lock nesting becomes a key concern as it can result in transitive blocking chains that force tasks to execute sequentially unnecessarily. Such chains can be quite long on a larger machine. Contention-sensitive real-time locking protocols have been proposed as a means of ``breaking'' transitive blocking chains, but such protocols tend to have high overhead due to more complicated lock/unlock logic. To ease such overhead, the usage of lock servers is considered herein. In particular, four specific lock-server paradigms are proposed and many nuances concerning their deployment are explored. Experiments are presented that show that, by executing cache hot, lock servers can enable reductions in lock/unlock overhead of up to 86\%. Such reductions make contention-sensitive protocols a viable approach in practice. This artifact contains the implementation of two contention-sensitive locking protocol variants implemented with four proposed lock-server paradigms, as well as the experiments with which they were evaluated. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Catherine E. Nemitz and Tanya Amert and James H. Anderson 2018 Is Part Of DARTS, Volume 4, Issue 2, Special Issue of the 30th Euromicro Conference on Real-Time Systems (ECRTS 2018) Article Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/DARTS.4.2.2 urn:nbn:de:0030-drops-89704 https://drops.dagstuhl.de/entities/document/10.4230/DARTS.4.2.2 eng https://creativecommons.org/licenses/by/3.0/de/legalcode