{"abstract":"A pointer leaves a link but its speculative prefetch still starts.","category":"Client state","checks":6,"contract":"Pointer dwell schedules per-link prefetch intent; leave cancels it, reentry restarts its clock, and each uninterrupted dwell starts at most once.","contract_signature":"events, dwell","evaluation_group":"s3-client-state-prefetch-intent-dwell","failed_approach":"The partial repair still violates at least one explicit regression oracle.","family":"s3-client-state-prefetch-intent-dwell","id":"FA-24746","implementations":{"attempt":{"sha256":"6781537b8cb41fdead59702b7f766208c14469d2da18af2d089920f8344a46cc","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events, dwell):\n    active={}\n    started=[]\n    for time,kind,key in events:\n        if kind=='enter': active[key]=time\n        elif kind=='tick':\n            for candidate,start in list(active.items()):\n                if time-start>=dwell:\n                    started.append(candidate); del active[candidate]\n    return started\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('leave cancels', solve([(0,'enter','a'),(1,'leave','a'),(5,'tick','')],3), [])\ncheck('dwell threshold', solve([(0,'enter','a'),(N,'tick','')],N), ['a'])\ncheck('not yet due', solve([(0,'enter','a'),(1,'tick','')],2), [])\ncheck('one launch', solve([(0,'enter','a'),(3,'tick',''),(5,'tick','')],2), ['a'])\ncheck('reentry resets dwell', solve([(0,'enter','a'),(1,'leave','a'),(3,'enter','a'),(4,'tick','')],2), [])\ncheck('independent links', solve([(0,'enter','a'),(1,'enter','b'),(2,'leave','a'),(3,'tick','')],2), ['b'])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"9fc15b104e093845a2f4fc12455f0bccd9b386b99e4c3c2118997c52287d9bd0","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events, dwell):\n    return list(dict.fromkeys(key for time,kind,key in events if kind=='enter'))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('leave cancels', solve([(0,'enter','a'),(1,'leave','a'),(5,'tick','')],3), [])\ncheck('dwell threshold', solve([(0,'enter','a'),(N,'tick','')],N), ['a'])\ncheck('not yet due', solve([(0,'enter','a'),(1,'tick','')],2), [])\ncheck('one launch', solve([(0,'enter','a'),(3,'tick',''),(5,'tick','')],2), ['a'])\ncheck('reentry resets dwell', solve([(0,'enter','a'),(1,'leave','a'),(3,'enter','a'),(4,'tick','')],2), [])\ncheck('independent links', solve([(0,'enter','a'),(1,'enter','b'),(2,'leave','a'),(3,'tick','')],2), ['b'])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"This models the stated application policy only; no browser or framework conformance is claimed. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"s3-client-state-prefetch-intent-dwell","generated_at":"2026-09-29T14:41:00.344618+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A bounded offline client-state transition with explicit lifecycle inputs.","root_cause":"The faulty implementation violates Pointer dwell schedules per-link prefetch intent; leave cancels it, reentry restarts its clock, and each uninterrupted dwell starts at most once.","sha256":"917e3aa19152a7e04251c5a61ab60d752bcd6027b4bb99461c78f7d1d32799cc","title":"A pointer leaves a link but its speculative prefetch still starts · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":42.049,"exit_code":1,"observations":[{"actual":["a"],"check":"leave cancels","expected":[],"passed":false},{"actual":["a"],"check":"dwell threshold","expected":["a"],"passed":true},{"actual":[],"check":"not yet due","expected":[],"passed":true},{"actual":["a"],"check":"one launch","expected":["a"],"passed":true},{"actual":[],"check":"reentry resets dwell","expected":[],"passed":true},{"actual":["a","b"],"check":"independent links","expected":["b"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"leave cancels\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"dwell threshold\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"not yet due\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"one launch\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"reentry resets dwell\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"independent links\", \"actual\": [\"a\", \"b\"], \"expected\": [\"b\"], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.275,"exit_code":1,"observations":[{"actual":["a"],"check":"leave cancels","expected":[],"passed":false},{"actual":["a"],"check":"dwell threshold","expected":["a"],"passed":true},{"actual":["a"],"check":"not yet due","expected":[],"passed":false},{"actual":["a"],"check":"one launch","expected":["a"],"passed":true},{"actual":["a"],"check":"reentry resets dwell","expected":[],"passed":false},{"actual":["a","b"],"check":"independent links","expected":["b"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"leave cancels\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"dwell threshold\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"not yet due\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"one launch\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"reentry resets dwell\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"independent links\", \"actual\": [\"a\", \"b\"], \"expected\": [\"b\"], \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}