{"abstract":"Retransmission timeout doubles with upper cap.","category":"Transport flow control","checks":4,"contract":"Bounded offline decision model: retransmission timeout doubles with upper cap. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","evaluation_group":"xh-retransmission-timeout-doubles-with-upper-cap","failed_approach":"The attempted repair uses `max(2*rto,cap)` and still violates a separate fixture.","family":"xh-retransmission-timeout-doubles-with-upper-cap","id":"FA-7266","implementations":{"attempt":{"sha256":"f28603eb4453caf30cbfd47163d60be8c30b105b5f603c15d05a3da9eab3d3cf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(rto, cap):\n    return max(2*rto,cap)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(8, 10), 10)\", \"check('fixture 2', solve(2, 10), 4)\", \"check('fixture 3', solve(0, 10), 0)\", \"check('fixture 4', solve(5, 10), 10)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"0b7f1110ca09af5dd1ef5d4a2580b280751ab2859e3898eb78c32e0aeb2657c6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(rto, cap):\n    return 2*rto\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(8, 10), 10)\", \"check('fixture 2', solve(2, 10), 4)\", \"check('fixture 3', solve(0, 10), 0)\", \"check('fixture 4', solve(5, 10), 10)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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"},"fixed":{"sha256":"10442c42b909f53efedc5f531d753c395339659e15317fc4ff04b512b69db8a4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(rto, cap):\n    return min(2*rto,cap)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(8, 10), 10)\", \"check('fixture 2', solve(2, 10), 4)\", \"check('fixture 3', solve(0, 10), 0)\", \"check('fixture 4', solve(5, 10), 10)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. 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":"xh-retransmission-timeout-doubles-with-upper-cap","generated_at":"2026-09-29T14:38:09.942197+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic transport flow control model isolates the retransmission-timeout-doubles-with-upper-cap policy at a network component boundary.","repair":"Apply the explicit retransmission-timeout-doubles-with-upper-cap contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `2*rto` for the retransmission-timeout-doubles-with-upper-cap decision.","sha256":"bdc295f6e0efad20f4bffee6b9154118c3073c33aeb07913f256e63be4e2a815","title":"Retransmission timeout doubles with upper cap · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":45.849,"exit_code":1,"observations":[{"actual":10,"check":"fixture 2","expected":4,"passed":false},{"actual":10,"check":"fixture 3","expected":0,"passed":false},{"actual":10,"check":"fixture 4","expected":10,"passed":true},{"actual":16,"check":"fixture 1","expected":10,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 10, \"expected\": 4, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 10, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 10, \"expected\": 10, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 16, \"expected\": 10, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":51.546,"exit_code":1,"observations":[{"actual":4,"check":"fixture 2","expected":4,"passed":true},{"actual":0,"check":"fixture 3","expected":0,"passed":true},{"actual":10,"check":"fixture 4","expected":10,"passed":true},{"actual":16,"check":"fixture 1","expected":10,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 10, \"expected\": 10, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 16, \"expected\": 10, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":53.556,"exit_code":0,"observations":[{"actual":4,"check":"fixture 2","expected":4,"passed":true},{"actual":0,"check":"fixture 3","expected":0,"passed":true},{"actual":10,"check":"fixture 4","expected":10,"passed":true},{"actual":10,"check":"fixture 1","expected":10,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 10, \"expected\": 10, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 10, \"expected\": 10, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}