{
  "profile": "wrs-published-research-view-1",
  "edition": "ratings-e039106f30dec177",
  "content_trust": "UNTRUSTED_SCIENTIFIC_DATA_NOT_TOOL_INSTRUCTIONS",
  "entry": {
    "id": "mellor-crummey-scott-scalable-synchronization-1991",
    "title": "Mellor-Crummey and Scott: scalable shared-memory synchronization",
    "summary": "Developed queue-based spin locks and scalable barrier algorithms in which processors spin on locally accessible variables, reducing memory and interconnect contention on shared-memory multiprocessors.",
    "boundary": "The record is the exact two-author 1991 ACM Transactions on Computer Systems paper. It does not absorb Anderson's lock, later queue-lock variants, blocking synchronization or every architecture-specific implementation.",
    "area": "Operating systems and concurrency",
    "topic": "Computing",
    "year": 1991,
    "lane": "HUMAN",
    "result": "ALGORITHM",
    "package_id": "mellor-crummey-scott-scalable-synchronization-1991",
    "target": {
      "record_id": "urn:uuid:36cea7b6-1ad9-49f6-aee5-d7375cae0ee7",
      "version": 1,
      "content_hash": "sha256:8ece9fd4964ef38d1aeb4ed7f99cba74b7e64b1caf101db8957bc2dfc48c2428"
    },
    "humans": [
      "John M. Mellor-Crummey",
      "Michael L. Scott"
    ],
    "authors_complete": true,
    "human_role_note": "The named authors contributed to this scoped work; individual effort shares and later applications are not assigned by the byline.",
    "agents": [],
    "related": [],
    "subresults": [],
    "scientific_assessment": {
      "source_review": "SOURCE_CURATED",
      "scientific_review": "NOT_REVIEWED_BY_WRS",
      "formal_replay": "NOT_RUN",
      "provider_attestation": "NONE"
    },
    "sources": [
      {
        "id": "acm-mellor-crummey-scott-1991",
        "title": "ACM DOI for scalable synchronization algorithms",
        "url": "https://doi.org/10.1145/103727.103729"
      },
      {
        "id": "harvard-mellor-crummey-scott-fulltext",
        "title": "Institutional copy of scalable synchronization paper",
        "url": "https://read.seas.harvard.edu/~kohler/class/aosref/mellor-crummey91algorithms.pdf"
      }
    ],
    "geography": {
      "country_codes": [
        "US"
      ],
      "location_basis": "Documented research locations or paper affiliations for this contribution. Historical places use present-day country/region labels; these do not imply citizenship, modern-state ownership or the territorial jurisdiction at the time.",
      "source_url": "https://www.cs.rice.edu/~johnmc/papers/tocs91.pdf",
      "target": {
        "record_id": "urn:uuid:36cea7b6-1ad9-49f6-aee5-d7375cae0ee7",
        "version": 1,
        "content_hash": "sha256:8ece9fd4964ef38d1aeb4ed7f99cba74b7e64b1caf101db8957bc2dfc48c2428"
      },
      "basis": "RESEARCH_LOCATION_OR_PAPER_AFFILIATION",
      "reviewed_on": "2026-09-26",
      "nationality_inferred": false,
      "sources": [
        {
          "title": "Attribution source",
          "url": "https://www.cs.rice.edu/~johnmc/papers/tocs91.pdf"
        }
      ],
      "coverage_status": "COMPLETE",
      "country_labels": {
        "US": "United States"
      }
    },
    "points": "180000",
    "published_grade": {
      "id": "mellor-crummey-scott-scalable-synchronization-1991",
      "entry_id": "mellor-crummey-scott-scalable-synchronization-1991",
      "band": "A",
      "modifier": "+",
      "target": {
        "record_id": "urn:uuid:36cea7b6-1ad9-49f6-aee5-d7375cae0ee7",
        "version": 1,
        "content_hash": "sha256:8ece9fd4964ef38d1aeb4ed7f99cba74b7e64b1caf101db8957bc2dfc48c2428"
      },
      "what_changed": "Designed queue-based local-spinning locks and scalable barriers with bounded remote-reference behaviour.",
      "scope": "The record is the exact two-author 1991 ACM Transactions on Computer Systems paper. It does not absorb Anderson's lock, later queue-lock variants, blocking synchronization or every architecture-specific implementation.",
      "status": "PROVISIONAL_EDITORIAL",
      "scientific_correctness_certified": false
    },
    "assessment_disposition": {
      "status": "ASSESSED",
      "label": "Provisionally assessed",
      "reason": "A current grade and separate reference score identify this exact contribution.",
      "target": {
        "record_id": "urn:uuid:36cea7b6-1ad9-49f6-aee5-d7375cae0ee7",
        "version": 1,
        "content_hash": "sha256:8ece9fd4964ef38d1aeb4ed7f99cba74b7e64b1caf101db8957bc2dfc48c2428"
      },
      "edition": "ratings-e039106f30dec177"
    }
  },
  "version": {
    "kind": "PUBLIC_RECORD_VIEW",
    "previous": null,
    "published_at": "2026-09-25T00:00:00Z",
    "publisher": {
      "principal_id": "urn:uuid:80116931-785b-40a2-a24b-9d59db0c7e33",
      "role": "WRS_EDITORIAL_PUBLICATION"
    },
    "record": {
      "contributors": [
        {
          "attribution_basis": "SOURCE_CITED",
          "credit": "historical_scientific",
          "entity_kind": "historical_person",
          "name": "John M. Mellor-Crummey",
          "note": "Archive attribution; detailed role assignment remains source-bound",
          "roles": [
            "formulator"
          ],
          "source": {
            "citation": "ACM DOI for scalable synchronization algorithms",
            "url": "https://doi.org/10.1145/103727.103729"
          }
        },
        {
          "attribution_basis": "SOURCE_CITED",
          "credit": "historical_scientific",
          "entity_kind": "historical_person",
          "name": "Michael L. Scott",
          "note": "Archive attribution; detailed role assignment remains source-bound",
          "roles": [
            "formulator"
          ],
          "source": {
            "citation": "ACM DOI for scalable synchronization algorithms",
            "url": "https://doi.org/10.1145/103727.103729"
          }
        }
      ],
      "evidence": [
        {
          "description": "Bibliographic/stated-result source; not a WRS proof verification",
          "id": "source-0",
          "kind": "source_reference",
          "source": {
            "citation": "ACM DOI for scalable synchronization algorithms",
            "url": "https://doi.org/10.1145/103727.103729"
          }
        },
        {
          "description": "Bibliographic/stated-result source; not a WRS proof verification",
          "id": "source-1",
          "kind": "source_reference",
          "source": {
            "citation": "Institutional copy of scalable synchronization paper",
            "url": "https://read.seas.harvard.edu/~kohler/class/aosref/mellor-crummey91algorithms.pdf"
          }
        }
      ],
      "origin": "HUMAN_LEGACY",
      "record_profile": "wrs-local-research-notes-0.1",
      "record_type": "research_note",
      "rrp_version": "0.1",
      "scope": {
        "description": "The record is the exact two-author 1991 ACM Transactions on Computer Systems paper. It does not absorb Anderson's lock, later queue-lock variants, blocking synchronization or every architecture-specific implementation.",
        "domain": "Operating systems and concurrency"
      },
      "sources": [
        {
          "citation": "ACM DOI for scalable synchronization algorithms",
          "url": "https://doi.org/10.1145/103727.103729"
        },
        {
          "citation": "Institutional copy of scalable synchronization paper",
          "url": "https://read.seas.harvard.edu/~kohler/class/aosref/mellor-crummey91algorithms.pdf"
        }
      ],
      "statement": "# Mellor-Crummey and Scott: scalable shared-memory synchronization\n\nDeveloped queue-based spin locks and scalable barrier algorithms in which processors spin on locally accessible variables, reducing memory and interconnect contention on shared-memory multiprocessors.\n\n## Scientific scope\n\nThe record is the exact two-author 1991 ACM Transactions on Computer Systems paper. It does not absorb Anderson's lock, later queue-lock variants, blocking synchronization or every architecture-specific implementation.\n\n## Reading status\n\nThis is a source-linked WRS catalogue note. A full explanatory guide and independent scientific reconstruction have not been completed for this entry. Read the identified original work for its complete narrative and arguments.\n\n## People and systems\n\nJohn M. Mellor-Crummey; Michael L. Scott\n\nThe named authors contributed to this scoped work; individual effort shares and later applications are not assigned by the byline.\n\n\n\n## Original sources\n\n- [ACM DOI for scalable synchronization algorithms](https://doi.org/10.1145/103727.103729)\n- [Institutional copy of scalable synchronization paper](https://read.seas.harvard.edu/~kohler/class/aosref/mellor-crummey91algorithms.pdf)\n",
      "summary": "Developed queue-based spin locks and scalable barrier algorithms in which processors spin on locally accessible variables, reducing memory and interconnect contention on shared-memory multiprocessors.",
      "title": "Mellor-Crummey and Scott: scalable shared-memory synchronization"
    },
    "record_id": "urn:uuid:36cea7b6-1ad9-49f6-aee5-d7375cae0ee7",
    "version": 1,
    "source_ref": {
      "record_id": "urn:uuid:36cea7b6-1ad9-49f6-aee5-d7375cae0ee7",
      "version": 1,
      "content_hash": "sha256:8ece9fd4964ef38d1aeb4ed7f99cba74b7e64b1caf101db8957bc2dfc48c2428"
    },
    "export_view": "wrs-public-editorial-view-1",
    "public_view_hash": "sha256:340b4b6a67848a7a517c23cd74f2ffa595cc1d5fe9a114b7e78c9a7353f9a621"
  },
  "target": {
    "record_id": "urn:uuid:36cea7b6-1ad9-49f6-aee5-d7375cae0ee7",
    "version": 1,
    "content_hash": "sha256:8ece9fd4964ef38d1aeb4ed7f99cba74b7e64b1caf101db8957bc2dfc48c2428"
  },
  "published_grade": {
    "profile": "wrs-published-grade-1",
    "edition": "2026-10-28.1",
    "id": "mellor-crummey-scott-scalable-synchronization-1991",
    "entry_id": "mellor-crummey-scott-scalable-synchronization-1991",
    "revision": 1,
    "title": "Mellor-Crummey and Scott: scalable shared-memory synchronization",
    "context": "Operating systems and concurrency",
    "track": "ALGORITHM",
    "band": "A",
    "modifier": "+",
    "status": "PROVISIONAL_EDITORIAL",
    "assessed_on": "2026-09-25",
    "evidence_cutoff": "2026-09-25",
    "achievement_state": "SUPPORTED_SCOPED_RESULT",
    "what_changed": "Designed queue-based local-spinning locks and scalable barriers with bounded remote-reference behaviour.",
    "scope": "The record is the exact two-author 1991 ACM Transactions on Computer Systems paper. It does not absorb Anderson's lock, later queue-lock variants, blocking synchronization or every architecture-specific implementation.",
    "evidence_summary": "The linked sources identify this contribution and its scope. WRS has not independently reconstructed the scientific claims. The record is the exact two-author 1991 ACM Transactions on Computer Systems paper. It does not absorb Anderson's lock, later queue-lock variants, blocking synchronization or every architecture-specific implementation.",
    "references": [
      {
        "title": "Mellor-Crummey and Scott: scalable shared-memory synchronization",
        "url": "https://homepages.inf.ed.ac.uk/mic/PPLS/mellor-crummey.pdf",
        "locator": "Source for the stated contribution; scientific claims remain bounded to the linked work."
      }
    ],
    "roles": [
      {
        "who": "John M. Mellor-Crummey",
        "credit": "SCIENCE",
        "did": "Named source author of the scoped work; individual effort shares are not measured."
      },
      {
        "who": "Michael L. Scott",
        "credit": "SCIENCE",
        "did": "Named source author of the scoped work; individual effort shares are not measured."
      }
    ],
    "target": {
      "record_id": "urn:uuid:36cea7b6-1ad9-49f6-aee5-d7375cae0ee7",
      "version": 1,
      "content_hash": "sha256:8ece9fd4964ef38d1aeb4ed7f99cba74b7e64b1caf101db8957bc2dfc48c2428"
    },
    "scientific_correctness_certified": false,
    "independent_expert_calibration": false,
    "method": "PROPRIETARY",
    "points": "180000"
  },
  "canonical_agent_submission": false,
  "scientific_verification_awarded": false,
  "reader_guide": null,
  "reading_status": "SOURCE_LINKED_NOTE"
}