xenia-rs/audit-runs/phase-c7-keSetEvent/re-validation.md

Phase C+7 — re-validation

Gate table

gate	result
1. cvar-OFF determinism (3 runs, 50M, --stable-digest)	PASS all 3 = c6d895829b4611964978990ae1cb8a6a (UNCHANGED from C+6½)
1b. cvar-OFF determinism (2 runs, 200M, --stable-digest)	PASS both = 8186841b38737f3cd1b3d2e91a35d108 (new 200M baseline)
2. Phase B image_loaded_sha256	PASS ea8d160e9369328a5b922258a92113efb8d7ce3e1a5c12cc521e375985c91c18 matches baseline
3. Phase A main matched prefix ≥ 102158	PASS 102158 (preserved — no main-chain regression, no #23 redux)
3b. Phase A sister chain tid=4→11 advances	PASS 5 → 9 (full alignment, no divergence in ours's 9-event window)
3c. Phase A sister chain tid=7→2 advances	PASS 26 → 29 (full alignment, no divergence in canary's 29-event window)
4. Both engines build clean	PASS ours: cargo build --release ok (pre-existing walk_committed_regions dead-code warning)
5. Phase A emitter determinism (det fields only)	PASS 2 runs 90fb28202b70cb43a63def7a2f8b470d byte-identical
6. Unit tests	PASS 146 → 152 (6 new, 0 modified, 0 regressed)

Gate 1 — 50M determinism

c6d895829b4611964978990ae1cb8a6a  digest-cvaroff-1.json
c6d895829b4611964978990ae1cb8a6a  digest-cvaroff-2.json
c6d895829b4611964978990ae1cb8a6a  digest-cvaroff-3.json

Digest is unchanged from C+6½ baseline. This is expected: --stable-digest reports (instructions, imports, draws, swaps, unique_render_targets, shader_blobs_live, texture_cache_entries), none of which are sensitive to KeSetEvent return-value within the 50M horizon. Imports stay at 40470 (the KeSetEvent change moves no new import call; only the return value of existing calls flips from 0 to 1). Draws stay at 0, swaps stay at 1.

Gate 1b — 200M stability

8186841b38737f3cd1b3d2e91a35d108  digest-cvaroff-200M-1.json
8186841b38737f3cd1b3d2e91a35d108  digest-cvaroff-200M-2.json

200M run is byte-deterministic across 2 runs. No 200M C+6½ baseline to compare against (none was captured), but the new digest is itself a regression marker for any future fix. Field values at 200M: imports=40470, draws=0, swaps=1 — same plateau as 50M.

Gate 3 — Phase A diff (all chains)

chain	C+6½ XAM	C+7	Δ
canary tid=6 → ours tid=1 (main)	102158	102158	0 (preserved)
canary tid=4 → ours tid=11	5	9	+4 (all ours events match)
canary tid=7 → ours tid=2	26	29	+3 (all canary events match)
canary tid=12 → ours tid=7	2	2	0 (different bug — KeWaitForSingleObject=258 vs 0)
canary tid=14 → ours tid=9	39	39	0 (different bug — XAudio vs RtlEnterCS)
canary tid=15 → ours tid=10	(no div)	(no div)	0

Two sister chains advanced exactly as predicted by the C+6½ memory note. Main chain (XamTaskCloseHandle at 102158) is explicitly unchanged — the KeSetEvent fix doesn't touch the XamTaskHandle path; that divergence remains the next session's target.

Gate 5 — emitter determinism

Phase A emitter run twice over the same boot, with all non-deterministic fields (host_ns, guest_cycle, engine, deterministic) stripped:

90fb28202b70cb43a63def7a2f8b470d  ours.jsonl
90fb28202b70cb43a63def7a2f8b470d  ours-determ.jsonl

Byte-identical det fields. New emitter-det baseline replaces C+6½'s 11a07772… — the return-value field is included in the deterministic schema, and KeSetEvent's contribution flipped from 0 to 1 on every emit.

Gate 6 — unit tests

cargo test -p xenia-kernel --release — 152/152 pass. New 6 tests:

• ke_set_event_returns_constant_one_on_unsignaled_auto_reset
• ke_set_event_returns_constant_one_on_already_signaled_manual_reset
• nt_set_event_null_prev_ptr_returns_status_success_no_write
• nt_set_event_valid_prev_ptr_writes_constant_one_and_returns_success
• nt_set_event_on_signaled_event_writes_one
• ke_set_event_post_fix_still_wakes_waiter

All existing 146 tests still pass — no regressions from the return-value flip (other test bodies don't assert on the return value of ke_set_event / nt_set_event).