FA-10951 / Audio playback scheduling / Open access
Schedule insert stable time order · case 01
Appending an earlier event breaks chronological dispatch.
ROOT CAUSE
Appending an earlier event breaks chronological dispatch.
VERIFIED REPAIR
Apply the explicit PCM/playback contract: Insert one [frame,event] into time-ordered events; equal timestamps preserve arrival order and do not sort payloads.
Unsuccessful approach: Sorting the full tuple reorders simultaneous events by payload.
Case contract
Insert one [frame,event] into time-ordered events; equal timestamps preserve arrival order and do not sort payloads.
Why this case matters
A pure Python local audio pipeline stage with explicit sample formats and frame conventions; no real-time device or signal-spectrum claims.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(events, incoming):
return list(events)+[incoming]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([[2, 'z'], [4, 'a']], [1, 'b'])),[[1, 'b'], [2, 'z'], [4, 'a']])
check('fixture 2',solve(*([[2, 'z']], [2, 'a'])),[[2, 'z'], [2, 'a']])
check('fixture 3',solve(*([], [0, 'x'])),[[0, 'x']])
check('fixture 4',solve(*([[1, 'a']], [3, 'b'])),[[1, 'a'], [3, 'b']])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1 | [[2, 'z'], [4, 'a'], [1, 'b']] | [[1, 'b'], [2, 'z'], [4, 'a']] | Failed |
| fixture 2 | [[2, 'z'], [2, 'a']] | [[2, 'z'], [2, 'a']] | Passed |
| fixture 3 | [[0, 'x']] | [[0, 'x']] | Passed |
| fixture 4 | [[1, 'a'], [3, 'b']] | [[1, 'a'], [3, 'b']] | Passed |
SHA-256 / 07365a36250e1bf24fafa3fb29966970847144dc37b15872a7dce3e1f38407c5
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(events, incoming):
return sorted(list(events)+[incoming])
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([[2, 'z'], [4, 'a']], [1, 'b'])),[[1, 'b'], [2, 'z'], [4, 'a']])
check('fixture 2',solve(*([[2, 'z']], [2, 'a'])),[[2, 'z'], [2, 'a']])
check('fixture 3',solve(*([], [0, 'x'])),[[0, 'x']])
check('fixture 4',solve(*([[1, 'a']], [3, 'b'])),[[1, 'a'], [3, 'b']])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1 | [[1, 'b'], [2, 'z'], [4, 'a']] | [[1, 'b'], [2, 'z'], [4, 'a']] | Passed |
| fixture 2 | [[2, 'a'], [2, 'z']] | [[2, 'z'], [2, 'a']] | Failed |
| fixture 3 | [[0, 'x']] | [[0, 'x']] | Passed |
| fixture 4 | [[1, 'a'], [3, 'b']] | [[1, 'a'], [3, 'b']] | Passed |
SHA-256 / 6a33b13b76672e84b397b30bbe82a0a337fa58bae061b7a955358ba5c2ebe2a0
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(events, incoming):
return sorted(list(events)+[incoming],key=lambda x:x[0])
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([[2, 'z'], [4, 'a']], [1, 'b'])),[[1, 'b'], [2, 'z'], [4, 'a']])
check('fixture 2',solve(*([[2, 'z']], [2, 'a'])),[[2, 'z'], [2, 'a']])
check('fixture 3',solve(*([], [0, 'x'])),[[0, 'x']])
check('fixture 4',solve(*([[1, 'a']], [3, 'b'])),[[1, 'a'], [3, 'b']])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1 | [[1, 'b'], [2, 'z'], [4, 'a']] | [[1, 'b'], [2, 'z'], [4, 'a']] | Passed |
| fixture 2 | [[2, 'z'], [2, 'a']] | [[2, 'z'], [2, 'a']] | Passed |
| fixture 3 | [[0, 'x']] | [[0, 'x']] | Passed |
| fixture 4 | [[1, 'a'], [3, 'b']] | [[1, 'a'], [3, 'b']] | Passed |
SHA-256 / 88752a4354a2a1f3cadf6ebef476c58d08e744aa0877847ba24f633201ea14c0
Verification & scope
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.
Observations recorded using Python 3.12.14 at 2026-09-29T14:38:43.719437+00:00.
Case digest / 8483ef1c35cca94f6737090e7a11f554aeaf4c3449d71440b432f44926538f01