# Phase C+15-α Schema-Wiring Audit (2026-05-14)

## Phase 1 — Wired/unwired matrix (pre-session)

| Kind                | Canary emits? | Ours emits? | Status (pre)  | Priority |
|---------------------|---------------|-------------|---------------|----------|
| `schema_version`    | yes           | yes         | wired         | —        |
| `import.call`       | yes           | yes         | wired         | —        |
| `kernel.call`       | yes           | yes         | wired (+C+10) | —        |
| `kernel.return`     | yes           | yes         | wired         | —        |
| `handle.create`     | declared      | declared    | **stubbed**   | HIGH     |
| `handle.destroy`    | declared      | declared    | **stubbed**   | HIGH     |
| `thread.create`     | declared      | declared    | **stubbed**   | HIGH     |
| `thread.exit`       | declared      | declared    | **stubbed**   | HIGH     |
| `wait.begin`        | declared      | declared    | **stubbed**   | HIGH     |
| `wait.end`          | declared      | declared    | **stubbed**   | HIGH     |
| `thread.suspend`    | declared      | not in API  | unwired       | LOW      |
| `thread.resume`     | declared      | not in API  | unwired       | LOW      |
| `vfs.open`          | declared      | not in API  | redundant?    | MEDIUM   |
| `vfs.read`          | declared      | not in API  | high-vol      | LOW      |
| `vfs.close`         | declared      | not in API  | redundant?    | MEDIUM   |
| `mem.write`         | declared      | not in API  | opt-in        | LOW      |

## Phase 2/3 — Kinds wired this session

Wired symmetrically in both engines (cvar-gated default-off):

- **`handle.create`** — emitted from `KernelState::alloc_handle_for` (ours) /
  `ObjectTable::AddHandle` (canary). 39+ call sites covered via centralized hook.
- **`handle.destroy`** — emitted from `nt_close` + `xam_task_close_handle` (ours) /
  `ObjectTable::RemoveHandle` (canary).
- **`thread.create`** — emitted from `ex_create_thread` (ours) / `ExCreateThread`
  in `xboxkrnl_threading.cc` (canary). After spawn succeeds.
- **`thread.exit`** — emitted from `ex_terminate_thread` (ours) / `XThread::Exit`
  (canary). Canary's `XThread::Exit` covers both explicit `ExTerminateThread`
  and implicit thread-entry returns.
- **`wait.begin`** — emitted from `nt_wait_for_single_object_ex` +
  `ke_wait_for_single_object` (ours) / `xeKeWaitForSingleObject` +
  `NtWaitForSingleObjectEx` (canary).

Deferred (v1.2):

- **`wait.end`** — design challenge: wait can park the guest thread, and the
  wake-status path differs between engines. Sync outcome status is already
  captured in the immediately-following `kernel.return`. Async wake outcome
  surfaced in subsequent events.
- **`thread.suspend` / `thread.resume`** — low-frequency; defer until needed.
- **`vfs.*`** — redundant with `kernel.call` for Nt*File. Skip per schema-v1
  audit recommendation.
- **`mem.write`** — opt-in only (separate cvar); high-volume.

## Code summary

### Ours (~140 LOC)

- `crates/xenia-kernel/src/event_log.rs` — registry + auto helpers
  (`register_handle_semantic_id`, `lookup_handle_semantic_id`,
  `forget_handle_semantic_id`, `emit_handle_create_auto`,
  `emit_handle_destroy_auto`). +85 LOC.
- `crates/xenia-kernel/src/objects.rs` — `KernelObject::schema_object_type()`.
  +14 LOC.
- `crates/xenia-kernel/src/state.rs` — `alloc_handle_for` emit hook. +24 LOC.
- `crates/xenia-kernel/src/exports.rs` — `nt_close` destroy emit,
  `ex_create_thread` thread.create emit, `ex_terminate_thread` thread.exit emit,
  `nt_wait_for_single_object_ex` + `ke_wait_for_single_object` wait.begin emits,
  + `decode_timeout_ns` helper. +85 LOC.
- `crates/xenia-kernel/src/xam.rs` — `xam_task_close_handle` destroy emit. +14 LOC.

### Canary (~130 LOC)

- `src/xenia/kernel/event_log.h` — registry API (`RegisterHandleSemanticId`,
  `LookupHandleSemanticId`, `ForgetHandleSemanticId`, `EmitHandleCreateAuto`,
  `EmitHandleDestroyAuto`). +20 LOC.
- `src/xenia/kernel/event_log.cc` — per-tid counter map (was per-host-thread
  `thread_local`; produced duplicate `tid_event_idx` for tid=0 across host
  threads — a bug in the pre-session implementation), `CurrentTid` non-asserting
  via new `XThread::TryGetCurrentThread`, registry helpers, auto-emit wrappers.
  +60 LOC net.
- `src/xenia/kernel/xthread.h` + `xthread.cc` — `TryGetCurrentThread` accessor
  + `XThread::Exit` thread.exit emit. +12 LOC.
- `src/xenia/kernel/util/object_table.cc` — `AddHandle`/`RemoveHandle` hooks
  + `SchemaObjectType` mapping. +35 LOC.
- `src/xenia/kernel/xboxkrnl/xboxkrnl_threading.cc` — `ExCreateThread`
  thread.create emit, `xeKeWaitForSingleObject` + `NtWaitForSingleObjectEx`
  wait.begin emits. +30 LOC.

### Diff tool

- `tools/diff-events/diff_events.py` — `SKIP_PAYLOAD_FIELDS_BY_KIND` now skips
  `handle_semantic_id` (cross-engine `creating_tid` differs, so SIDs are
  engine-local), `parent_tid`, `handles_semantic_ids`, `woken_by_semantic_id`.
  +6 LOC.

## Bug found and fixed this session

**Pre-session bug**: canary's `t_tid_event_idx` was a host-thread-local global,
not a tid-keyed counter. When `AddHandle` runs from multiple host threads with
tid==0 (boot init + early XThread bootstrap before guest tid is assigned), each
host thread had its own counter starting at 0, producing duplicate
`tid_event_idx` values within the tid=0 stream. The diff tool rejected the
file with "events out of order at index 8". Fixed by replacing the thread_local
with a tid-keyed `std::unordered_map` + mutex (matches ours's design).