# Phase A diff report

**This report is the output of Phase A's diff harness. Divergences
shown here are INPUT for Phase B (first-divergence localization),
not findings of Phase A.** Phase A's job is to make the harness
itself correct, not to analyze what it surfaces.

## Summary

| canary_tid | ours_tid | matched | canary_total | ours_total | first_divergence_at | floating_create (c/o) | floating_wait (c/o) |
|---|---|---|---|---|---|---|---|
| 4 | 11 | 11 | 75287 | 11 | — | 0/0 | 0/0 |
| 6 | 1 | 105046 | 351340 | 108507 | 105046 | 0/0 | 1/0 |
| 7 | 2 | 32 | 32 | 33 | — | 0/0 | 0/0 |
| 12 | 7 | 4 | 9264 | 5 | 4 | 0/0 | 0/0 |
| 14 | 9 | 41 | 1904055 | 77 | 41 | 0/0 | 0/0 |
| 15 | 10 | 16 | 995517 | 17 | — | 0/1 | 0/0 |

*`floating_create (c/o)` counts shared-global `handle.create` events absorbed by Phase C+18 cross-tid SID matching. `floating_wait (c/o)` counts `wait.begin` events on shared-global dispatchers absorbed by Phase C+21 (scheduling-jitter window — canary's contention slow path may fire while ours fast-paths or vice versa). See schema-v1.md §"Shared-global SIDs" and §"Wait-begin floating absorb".*

## canary_tid=4 → ours_tid=11

No divergence within the 11 compared events (canary has 75287, ours has 11).

## canary_tid=6 → ours_tid=1

First divergence at `tid_event_idx=105046`: payload.return_value: canary=1 ours=0

**Pre-context (last 5 matching events):**
```
  canary: [105048] import.call RtlInitializeCriticalSection
  ours:   [105041] import.call RtlInitializeCriticalSection
  canary: [105049] kernel.call RtlInitializeCriticalSection
  ours:   [105042] kernel.call RtlInitializeCriticalSection
  canary: [105050] kernel.return RtlInitializeCriticalSection
  ours:   [105043] kernel.return RtlInitializeCriticalSection
  canary: [105051] import.call VdInitializeEngines
  ours:   [105044] import.call VdInitializeEngines
  canary: [105052] kernel.call VdInitializeEngines
  ours:   [105045] kernel.call VdInitializeEngines
```

**Divergent event:**
```
  canary: [105053] kernel.return VdInitializeEngines
  ours:   [105046] kernel.return VdInitializeEngines
```

**Next event after the divergence (if any):**
```
  canary: [105054] import.call VdShutdownEngines
  ours:   [105047] import.call VdShutdownEngines
```

**Raw events (JSON):**
```json
{"deterministic": true, "engine": "canary", "guest_cycle": 0, "host_ns": 1637248100, "kind": "kernel.return", "payload": {"name": "VdInitializeEngines", "return_value": 1, "side_effects": [], "status": "0x00000001"}, "schema_version": 1, "tid": 6, "tid_event_idx": 105053}
{"deterministic": true, "engine": "ours", "guest_cycle": 5541402, "host_ns": 523232070, "kind": "kernel.return", "payload": {"name": "VdInitializeEngines", "return_value": 0, "side_effects": [], "status": "0x00000000"}, "schema_version": 1, "tid": 1, "tid_event_idx": 105046}
```

## canary_tid=7 → ours_tid=2

No divergence within the 32 compared events (canary has 32, ours has 33).

## canary_tid=12 → ours_tid=7

First divergence at `tid_event_idx=4`: payload.return_value: canary=258 ours=0

**Pre-context (last 5 matching events):**
```
  canary: [0] import.call KeWaitForSingleObject
  ours:   [0] import.call KeWaitForSingleObject
  canary: [1] kernel.call KeWaitForSingleObject
  ours:   [1] kernel.call KeWaitForSingleObject
  canary: [2] handle.create sid=c49d8f0ab90401ea
  ours:   [2] handle.create sid=6e3d96c5a52bf429
  canary: [3] wait.begin {'handles_semantic_ids': ['c49d8f0ab90401ea'], 'timeout_ns': -30000000, 'alertable': False, 'wait_type': 'any'}
  ours:   [3] wait.begin {'handles_semantic_ids': ['6e3d96c5a52bf429'], 'timeout_ns': -30000000, 'alertable': False, 'wait_type': 'any'}
```

**Divergent event:**
```
  canary: [4] kernel.return KeWaitForSingleObject
  ours:   [4] kernel.return KeWaitForSingleObject
```

**Next event after the divergence (if any):**
```
  canary: [5] import.call RtlEnterCriticalSection
  ours:   <end of stream>
```

**Raw events (JSON):**
```json
{"deterministic": true, "engine": "canary", "guest_cycle": 0, "host_ns": 1676368000, "kind": "kernel.return", "payload": {"name": "KeWaitForSingleObject", "return_value": 258, "side_effects": [], "status": "0x00000102"}, "schema_version": 1, "tid": 12, "tid_event_idx": 4}
{"deterministic": true, "engine": "ours", "guest_cycle": 30, "host_ns": 523599940, "kind": "kernel.return", "payload": {"name": "KeWaitForSingleObject", "return_value": 0, "side_effects": [], "status": "0x00000000"}, "schema_version": 1, "tid": 7, "tid_event_idx": 4}
```

## canary_tid=14 → ours_tid=9

First divergence at `tid_event_idx=41`: payload.ord: canary=503 ours=293

**Pre-context (last 5 matching events):**
```
  canary: [36] kernel.call KeReleaseSpinLockFromRaisedIrql
  ours:   [36] kernel.call KeReleaseSpinLockFromRaisedIrql
  canary: [37] kernel.return KeReleaseSpinLockFromRaisedIrql
  ours:   [37] kernel.return KeReleaseSpinLockFromRaisedIrql
  canary: [38] import.call KfLowerIrql
  ours:   [38] import.call KfLowerIrql
  canary: [39] kernel.call KfLowerIrql
  ours:   [39] kernel.call KfLowerIrql
  canary: [40] kernel.return KfLowerIrql
  ours:   [40] kernel.return KfLowerIrql
```

**Divergent event:**
```
  canary: [41] import.call XAudioGetVoiceCategoryVolumeChangeMask
  ours:   [41] import.call RtlEnterCriticalSection
```

**Next event after the divergence (if any):**
```
  canary: [42] kernel.call XAudioGetVoiceCategoryVolumeChangeMask
  ours:   [42] kernel.call RtlEnterCriticalSection
```

**Raw events (JSON):**
```json
{"deterministic": true, "engine": "canary", "guest_cycle": 0, "host_ns": 1898677900, "kind": "import.call", "payload": {"module": "xboxkrnl.exe", "name": "XAudioGetVoiceCategoryVolumeChangeMask", "ord": 503}, "schema_version": 1, "tid": 14, "tid_event_idx": 41}
{"deterministic": true, "engine": "ours", "guest_cycle": 417, "host_ns": 1753797001, "kind": "import.call", "payload": {"module": "xboxkrnl.exe", "name": "RtlEnterCriticalSection", "ord": 293}, "schema_version": 1, "tid": 9, "tid_event_idx": 41}
```

## canary_tid=15 → ours_tid=10

No divergence within the 16 compared events (canary has 995517, ours has 17).