# 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) |
|---|---|---|---|---|---|---|---|
| 6 | 1 | 105138 | 445578 | 108507 | 105138 | 1/0 | 3/0 |

*`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=6 → ours_tid=1

First divergence at `tid_event_idx=105138`: payload.return_value: canary=3 ours=0

**Pre-context (last 5 matching events):**
```
  canary: [105143] import.call VdQueryVideoMode
  ours:   [105133] import.call VdQueryVideoMode
  canary: [105144] kernel.call VdQueryVideoMode
  ours:   [105134] kernel.call VdQueryVideoMode
  canary: [105145] kernel.return VdQueryVideoMode
  ours:   [105135] kernel.return VdQueryVideoMode
  canary: [105146] import.call VdQueryVideoFlags
  ours:   [105136] import.call VdQueryVideoFlags
  canary: [105147] kernel.call VdQueryVideoFlags
  ours:   [105137] kernel.call VdQueryVideoFlags
```

**Divergent event:**
```
  canary: [105148] kernel.return VdQueryVideoFlags
  ours:   [105138] kernel.return VdQueryVideoFlags
```

**Next event after the divergence (if any):**
```
  canary: [105149] import.call VdCallGraphicsNotificationRoutines
  ours:   [105139] import.call VdCallGraphicsNotificationRoutines
```

**Raw events (JSON):**
```json
{"deterministic": true, "engine": "canary", "guest_cycle": 0, "host_ns": 1605634900, "kind": "kernel.return", "payload": {"name": "VdQueryVideoFlags", "return_value": 3, "side_effects": [], "status": "0x00000003"}, "schema_version": 1, "tid": 6, "tid_event_idx": 105148}
{"deterministic": true, "engine": "ours", "guest_cycle": 5544516, "host_ns": 480313469, "kind": "kernel.return", "payload": {"name": "VdQueryVideoFlags", "return_value": 0, "side_effects": [], "status": "0x00000000"}, "schema_version": 1, "tid": 1, "tid_event_idx": 105138}
```