FA-11001 / Audio playback scheduling / Open access
Stream reset discards old carry · case 01
Resetting the cursor retains samples from the previous stream incarnation.
ROOT CAUSE
Resetting the cursor retains samples from the previous stream incarnation.
VERIFIED REPAIR
Apply the explicit PCM/playback contract: Resetting playback clears incomplete frame carry and cursor together; without reset preserve both.
Unsuccessful approach: Unconditional reset clears carry and progress during ordinary playback.
Case contract
Resetting playback clears incomplete frame carry and cursor together; without reset preserve both.
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(carry, position, resetting):
return [list(carry),0] if resetting else [list(carry),position]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([1], 8, True)),[[], 0])
check('fixture 2',solve(*([1], 8, False)),[[1], 8])
check('fixture 3',solve(*([], 0, True)),[[], 0])
check('fixture 4',solve(*([2, 3], 4, False)),[[2, 3], 4])
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], 0] | [[], 0] | Failed |
| fixture 2 | [[1], 8] | [[1], 8] | Passed |
| fixture 3 | [[], 0] | [[], 0] | Passed |
| fixture 4 | [[2, 3], 4] | [[2, 3], 4] | Passed |
SHA-256 / 18f1aaa879a720640952b0b03e1f96be87edc509b00a57598ffd2cfcf4ebdb81
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(carry, position, resetting):
return [[],0]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([1], 8, True)),[[], 0])
check('fixture 2',solve(*([1], 8, False)),[[1], 8])
check('fixture 3',solve(*([], 0, True)),[[], 0])
check('fixture 4',solve(*([2, 3], 4, False)),[[2, 3], 4])
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 | [[], 0] | [[], 0] | Passed |
| fixture 2 | [[], 0] | [[1], 8] | Failed |
| fixture 3 | [[], 0] | [[], 0] | Passed |
| fixture 4 | [[], 0] | [[2, 3], 4] | Failed |
SHA-256 / 39ce11cf29387e95ea62e2e8846f28dd50f8c2ecb78effa52ec21a258a49dd47
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(carry, position, resetting):
return [[],0] if resetting else [list(carry),position]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([1], 8, True)),[[], 0])
check('fixture 2',solve(*([1], 8, False)),[[1], 8])
check('fixture 3',solve(*([], 0, True)),[[], 0])
check('fixture 4',solve(*([2, 3], 4, False)),[[2, 3], 4])
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 | [[], 0] | [[], 0] | Passed |
| fixture 2 | [[1], 8] | [[1], 8] | Passed |
| fixture 3 | [[], 0] | [[], 0] | Passed |
| fixture 4 | [[2, 3], 4] | [[2, 3], 4] | Passed |
SHA-256 / 7dbce8a951f4451e49484cf874105c0a0e6bf6a7d26bd26b2ff391eef6e0b505
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 2026-09-29T14:38:44.134957+00:00.
Case digest / 1c77a5a84a86ef5cfd2c508ab402a69851009792adac415f962b1017eef95a7a