{"abstract":"A boundary event is scheduled in two adjacent callbacks.","category":"Audio playback scheduling","checks":4,"contract":"Select timestamped events in the callback frame interval [start,start+frames), returning callback-relative frame offsets.","contract_signature":"events, start, frames","evaluation_group":"xaud-callback-event-half-open-window","failed_approach":"Filtering correctly but retaining absolute timestamps places events beyond the current block.","family":"xaud-callback-event-half-open-window","id":"FA-10946","implementations":{"attempt":{"sha256":"1dbe34befbfdb888c0a1fc27e3d8d0ef41e055a28aa424e2620424ecb4a3fa84","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(events, start, frames):\n    return [[time,value] for time,value in events if start<=time<start+frames]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[10, 'a'], [13, 'b'], [14, 'c']], 10, 4)),[[0, 'a'], [3, 'b']])\ncheck('fixture 2',solve(*([[4, 'a']], 4, 0)),[])\ncheck('fixture 3',solve(*([[3, 'a']], 4, 2)),[])\ncheck('fixture 4',solve(*([[0, 'a']], 0, 1)),[[0, 'a']])\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":"4aaed42710b5d01845485dd09f9cf9f9655b4b50f982eae540219b72baf94053","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(events, start, frames):\n    return [[time-start,value] for time,value in events if start<=time<=start+frames]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[10, 'a'], [13, 'b'], [14, 'c']], 10, 4)),[[0, 'a'], [3, 'b']])\ncheck('fixture 2',solve(*([[4, 'a']], 4, 0)),[])\ncheck('fixture 3',solve(*([[3, 'a']], 4, 2)),[])\ncheck('fixture 4',solve(*([[0, 'a']], 0, 1)),[[0, 'a']])\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 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":"xaud-callback-event-half-open-window","generated_at":"2026-09-29T14:38:43.674649+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A pure Python local audio pipeline stage with explicit sample formats and frame conventions; no real-time device or signal-spectrum claims.","root_cause":"A boundary event is scheduled in two adjacent callbacks.","sha256":"b1432206ae6a224479cf8639b7c62de6b479dd0d9519c50350dc74bcb900c1e9","title":"Callback event half open window · 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":39.419,"exit_code":1,"observations":[{"actual":[[10,"a"],[13,"b"]],"check":"fixture 1","expected":[[0,"a"],[3,"b"]],"passed":false},{"actual":[],"check":"fixture 2","expected":[],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[[0,"a"]],"check":"fixture 4","expected":[[0,"a"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[10, \"a\"], [13, \"b\"]], \"expected\": [[0, \"a\"], [3, \"b\"]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[0, \"a\"]], \"expected\": [[0, \"a\"]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.191,"exit_code":1,"observations":[{"actual":[[0,"a"],[3,"b"],[4,"c"]],"check":"fixture 1","expected":[[0,"a"],[3,"b"]],"passed":false},{"actual":[[0,"a"]],"check":"fixture 2","expected":[],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[[0,"a"]],"check":"fixture 4","expected":[[0,"a"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[0, \"a\"], [3, \"b\"], [4, \"c\"]], \"expected\": [[0, \"a\"], [3, \"b\"]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[0, \"a\"]], \"expected\": [], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[0, \"a\"]], \"expected\": [[0, \"a\"]], \"passed\": true}], \"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."}}