{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,30]],"date-time":"2025-08-30T17:19:03Z","timestamp":1756574343557,"version":"3.41.0"},"reference-count":24,"publisher":"Association for Computing Machinery (ACM)","issue":"1","license":[{"start":{"date-parts":[[2014,1,1]],"date-time":"2014-01-01T00:00:00Z","timestamp":1388534400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.acm.org\/publications\/policies\/copyright_policy#Background"}],"funder":[{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council of Canada","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["dl.acm.org"],"crossmark-restriction":true},"short-container-title":["J. ACM"],"published-print":{"date-parts":[[2014,1]]},"abstract":"<jats:p>\n            This article is concerned with the problem of implementing an unbounded timestamp object from multiwriter atomic registers, in an asynchronous distributed system of\n            <jats:italic>n<\/jats:italic>\n            processes with distinct identifiers where timestamps are taken from an arbitrary universe. Ellen et al. [2008] showed that \u221a\n            <jats:italic>n<\/jats:italic>\n            \/2 \u2212\n            <jats:italic>O<\/jats:italic>\n            (1) registers are required for any obstruction-free implementation of long-lived timestamp systems from atomic registers (meaning processes can repeatedly get timestamps).\n          <\/jats:p>\n          <jats:p>\n            We improve this existing lower bound in two ways. First we establish a lower bound of\n            <jats:italic>n<\/jats:italic>\n            \/6 \u2212 1 registers for the obstruction-free long-lived timestamp problem. Previous such linear lower bounds were only known for constrained versions of the timestamp problem. This bound is asymptotically tight; Ellen et al. [2008] constructed a wait-free algorithm that uses\n            <jats:italic>n<\/jats:italic>\n            \u2212 1 registers. Second we show that \u221a2\n            <jats:italic>n<\/jats:italic>\n            \u2212 log\n            <jats:italic>n<\/jats:italic>\n            \u2212\n            <jats:italic>O<\/jats:italic>\n            (1) registers are required for any obstruction-free implementation of one-shot timestamp systems (meaning each process can get a timestamp at most once). We show that this bound is also asymptotically tight by providing a wait-free one-shot timestamp system that uses at most \u23082\u221a\n            <jats:italic>n<\/jats:italic>\n            \u2309 registers, thus establishing a space complexity gap between one-shot and long-lived timestamp systems.\n          <\/jats:p>","DOI":"10.1145\/2559904","type":"journal-article","created":{"date-parts":[[2014,2,4]],"date-time":"2014-02-04T14:16:21Z","timestamp":1391523381000},"page":"1-25","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":10,"title":["The Space Complexity of Long-Lived and One-Shot Timestamp Implementations"],"prefix":"10.1145","volume":"61","author":[{"given":"Maryam","family":"Helmi","sequence":"first","affiliation":[{"name":"University of Calgary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lisa","family":"Higham","sequence":"additional","affiliation":[{"name":"University of Calgary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eduardo","family":"Pacheco","sequence":"additional","affiliation":[{"name":"Universidad Nacional Automoma de Mexico and University of Calgary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Philipp","family":"Woelfel","sequence":"additional","affiliation":[{"name":"University of Calgary"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"320","published-online":{"date-parts":[[2014,1]]},"reference":[{"key":"e_1_2_1_1_1","doi-asserted-by":"publisher","DOI":"10.1145\/62546.62594"},{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1145\/153724.153741"},{"key":"e_1_2_1_3_1","doi-asserted-by":"publisher","DOI":"10.1145\/177492.177731"},{"key":"e_1_2_1_4_1","doi-asserted-by":"publisher","DOI":"10.1145\/792538.792541"},{"key":"e_1_2_1_5_1","doi-asserted-by":"publisher","DOI":"10.1006\/inco.1993.1065"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1137\/S0097539790192647"},{"key":"e_1_2_1_7_1","doi-asserted-by":"publisher","DOI":"10.1145\/324133.324161"},{"key":"e_1_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00446-008-0060-6"},{"key":"e_1_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.1145\/290179.290183"},{"key":"e_1_2_1_10_1","volume-title":"Proceedings of the 11th Australian Computer Science Conference (ACSC\u201988)","author":"Fidge C. J.","year":"1988","unstructured":"Fidge, C. J. 1988. Timestamps in message-passing systems that preserve the partial ordering. In Proceedings of the 11th Australian Computer Science Conference (ACSC\u201988). 56--66."},{"key":"e_1_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1145\/59287.59292"},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.5555\/146062.146078"},{"key":"e_1_2_1_13_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00446-007-0042-0"},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1145\/505241.505246"},{"key":"e_1_2_1_15_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF02242708"},{"key":"e_1_2_1_16_1","doi-asserted-by":"publisher","DOI":"10.5555\/645949.675325"},{"key":"e_1_2_1_17_1","doi-asserted-by":"publisher","DOI":"10.1145\/361082.361093"},{"key":"e_1_2_1_18_1","doi-asserted-by":"publisher","DOI":"10.1145\/359545.359563"},{"key":"e_1_2_1_19_1","doi-asserted-by":"publisher","DOI":"10.1145\/234533.234556"},{"key":"e_1_2_1_20_1","volume-title":"Proceedings of the Workshop on Parallel and Distributed Algorithms. 215--226","author":"Mattern F.","year":"1989","unstructured":"Mattern, F. 1989. Virtual time and global states of distributed systems. In Proceedings of the Workshop on Parallel and Distributed Algorithms. 215--226."},{"key":"e_1_2_1_21_1","doi-asserted-by":"publisher","DOI":"10.1145\/358527.358537"},{"key":"e_1_2_1_22_1","doi-asserted-by":"publisher","DOI":"10.1109\/TSE.1987.232564"},{"key":"e_1_2_1_23_1","doi-asserted-by":"publisher","DOI":"10.1109\/SFCS.1986.11"},{"key":"e_1_2_1_24_1","doi-asserted-by":"publisher","DOI":"10.1145\/12485.12491"}],"container-title":["Journal of the ACM"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/2559904","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.1145\/2559904","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T08:10:25Z","timestamp":1750234225000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/2559904"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,1]]},"references-count":24,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2014,1]]}},"alternative-id":["10.1145\/2559904"],"URL":"https:\/\/doi.org\/10.1145\/2559904","relation":{},"ISSN":["0004-5411","1557-735X"],"issn-type":[{"type":"print","value":"0004-5411"},{"type":"electronic","value":"1557-735X"}],"subject":[],"published":{"date-parts":[[2014,1]]},"assertion":[{"value":"2011-11-01","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2013-10-01","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2014-01-01","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}