# Phase C+22 re-validation (2026-05-18)

## Protocol followed

Cold-vs-cold per reading-error #31 + #32 + #33 + the new #34.

1. ✓ Backed up both canary cache locations
   (`xenia-canary/build-cross/bin/Windows/Debug/cache/` and
   `~/.local/share/Xenia/cache/`) to tarballs.
2. ✓ Wiped both canary caches + ours's
   (`~/.local/share/xenia-rs/cache/`).
3. ✓ Cold-ran ours (50M instructions) against the `.iso`
   path — NOT the loose `default.xex` (per new
   reading-error #34).
4. ✓ Cold-ran canary (90s timeout) against the `.iso` path
   with `--mute=true`.
5. ✓ Truncated canary log to first 250k events per tid
   (keeping ALL tids, NOT only tid=6 — needed for the C+18 /
   C+21 cross-tid shared-global heuristic).
6. ✓ Ran `diff_events.py` with full tid map
   `6=1,7=2,4=11,12=7,14=9,15=10`.
7. ✓ Restored both canary cache backups.

## Determinism check

- ours-cold byte-identical to C+19 archive (`audit-runs/
  phase-c19-NtDuplicateObject-handle-create/ours-cold.jsonl`):
  121,569 events match post-normalization (host_ns and
  guest_cycle excluded). Reproduces deterministically.
- No new engine source changes, so digest unchanged. Phase B
  `image_loaded_sha256 = ea8d160e9369328a5b922258a92113efb8d
  7ce3e1a5c12cc521e375985c91c18` preserved.

## Gate matrix (escalation mode)

| gate                                        | result            |
|---------------------------------------------|-------------------|
| Engine source unchanged                     | PASS              |
| Diff-tool source unchanged                  | PASS              |
| Phase A schema version 1 unchanged          | PASS              |
| ours-cold byte-equivalent to C+19 archive   | PASS (121,569 ev) |
| Main matched-prefix preserved at C+21       | PASS (104,607)    |
| Sister chains preserved (11/32/3/41/16)     | PASS              |
| C+21 absorber engaged (validation)          | PASS (2/0 wait)   |
| C+18 absorber engaged (validation)          | PASS (1/0 create) |
| Phase B image hash preserved                | PASS              |
| Canary caches restored                      | PASS              |
| Reading-error #34 documented + reproducible | PASS              |
| Tests count (no change)                     | 204 (unchanged)   |

## What changed in the diff-tool report compared to C+21 baseline

NOTHING substantive. The numbers are identical:

| chain                       | C+21 (jitter-1) | C+22 (fresh c22) |
|-----------------------------|-----------------|------------------|
| tid=6→1                     | 104,607         | 104,607          |
| tid=4→11                    | 11              | 11               |
| tid=7→2                     | 32              | 32               |
| tid=12→7                    | 3               | 3                |
| tid=14→9                    | 41              | 41               |
| tid=15→10                   | 16              | 16               |
| main floating_create (c/o)  | 0 / 0           | 1 / 0            |
| main floating_wait (c/o)    | 1 / 0           | 2 / 0            |

The floating counts vary across canary cold samples (different
host-scheduler interleavings emit the wait.begin in different
counts and at different indices) but the matched-prefix is
constant — this is the C+21 fix working as designed.

## Outcome

- C+22 = ESCALATION (no engine change).
- Cold-vs-cold environment is healthy and reproducible.
- C+21 absorber works correctly under varying contention.
- Reading-error #34 added as a methodology guard for future
  cold-vs-cold runs.
- Next-target list updated: C+23 = D-NEW-2 (independent
  ε-class), C+24 = D-NEW-3 (XAudio), parallel scheduler-
  determinism track.