diff --git a/archreview/2026-08-19/remediation/00-tracking.md b/archreview/2026-08-19/remediation/00-tracking.md
index 2822cd0..97def11 100644
--- a/archreview/2026-08-19/remediation/00-tracking.md
+++ b/archreview/2026-08-19/remediation/00-tracking.md
@@ -18,7 +18,7 @@ This plan is executed as **seven parallel batches**, each by one subagent workin
| C | `fix/c3-tracker-hygiene` | GWC-31 + housekeeping (close GWC-16/IPC-08/IPC-31, refresh TST-06/TST-17, register WRK-31) | sonnet | Cross-file comment/ID sweep needs care about what each ID *means*, but no logic changes | Not started |
| D | `fix/c3-dashboard-acl` | SEC-40, SEC-41, GWC-38 | opus | Authorization semantics, fail-closed decisions, claims re-resolution; each needs a regression test | Not started |
| E | `fix/c3-ipc-boundaries` | IPC-33, IPC-39, IPC-34, IPC-35 | opus | Changes the WorkerClient command lifecycle, the options validator, and the worker drain budget; race-sensitive | Not started |
-| F | `fix/c3-worker-residuals` | WRK-32, WRK-33 (+WRK-34 opportunistic) | sonnet | Small, precisely located worker edits + doc prose; cannot be built on macOS so the agent's job is a careful, minimal diff | Not started |
+| F | `fix/c3-worker-residuals` | WRK-32, WRK-33 (+WRK-34 opportunistic) | sonnet | Small, precisely located worker edits + doc prose; cannot be built on macOS so the agent's job is a careful, minimal diff | Done-pending-windev |
| G | `fix/c3-session-lifecycle` | GWC-32, GWC-34, GWC-37 | opus | Distributor/dispose lifecycle races and an alarm-monitor re-resolve path; needs lock-discipline reasoning | Not started |
**Out of scope for this execution (recorded, not dropped):**
@@ -66,6 +66,7 @@ This plan is executed as **seven parallel batches**, each by one subagent workin
- WRK-32: one `pumpStep()` before capturing the `CurrentVersion` baseline in `MxAccessCommandExecutor.cs`; rewrite the executor doc comment (`:996-1003`) to state the recency-based contract; add the same to `docs/MxAccessWorkerInstanceDesign.md` write-completion section and the reply-field comment in `mxaccess_gateway.proto` (**comment-only proto edit → regenerate all generated artifacts in the same commit**, per the repo rule; if regen tooling is unavailable on macOS, skip the proto comment and say so).
- WRK-34 if trivial: `CreateFault(StaHung, "Watchdog", …)` with the correlation id moved into the message.
- Cannot build on macOS: keep diff minimal, net48-safe (no init-only/positional records). Verified on windev afterwards.
+- **Done-pending-windev** (`93edb1b` WRK-33, `20a3eef` WRK-32, `3679e59` WRK-34) on `fix/c3-worker-residuals`. WRK-32 applied `CaptureCompletionBaseline` (pump-then-snapshot) uniformly to all four write call sites (Write/Write2/WriteSecured/WriteSecured2), not just the two the finding cited as evidence, since the correlation gap is identical at all four. **Deferred**: the `mxaccess_gateway.proto` reply-field comment was not edited — a comment-only proto change still requires regenerating every generated artifact (C#, Go, Python, Java, Rust, protoset) per the repo rule, and this macOS box cannot verify all five client generator pins for a Low-severity doc-only change; the contract is documented in `docs/MxAccessWorkerInstanceDesign.md` instead. `NonWindows.slnx` builds clean (0 warnings/errors); worker/Worker.Tests unverified until windev runs `MxAccessCommandExecutorTests`/`WorkerPipeSessionTests`.
### G — GWC-32, GWC-34, GWC-37 (opus)
- GWC-32: `DisposeAsync` transitions `_state` to `Closed` under `_syncRoot` before completing channels (or `if (_disposed || IsTerminalState()) return;` in `StageWorkerEvent`); update the XML doc to name all three completion paths. Test: dispose a Ready client mid-dispatch → no `ProtocolViolation` fault/metric.
diff --git a/docs/MxAccessWorkerInstanceDesign.md b/docs/MxAccessWorkerInstanceDesign.md
index 28f49a1..fab6491 100644
--- a/docs/MxAccessWorkerInstanceDesign.md
+++ b/docs/MxAccessWorkerInstanceDesign.md
@@ -317,6 +317,30 @@ whose write workload is effectively fire-and-forget — no consumer reads the
reply's `statuses` — can lower it, or set `0` to skip the wait entirely and
reply on acceptance alone.
+**Write-completion correlation is recency-based, not per-call.** MXAccess's
+`OnWriteComplete` callback carries no correlation token — only the server/item
+handle pair — so `MxAccessCommandExecutor` correlates a completion to a write
+by *version*: it snapshots `MxAccessWriteCompletionCache.CurrentVersion` for
+the handle as a baseline before the COM call, then reports the first
+completion whose version exceeds that baseline as the write's outcome
+(`AwaitWriteCompletion`). This is exact for the common case, but if an earlier
+write to the same handle times out unconfirmed — its `OnWriteComplete` still
+undelivered when the wait gives up — and the caller immediately issues another
+write to the same tag, the stale callback can dispatch during the second
+write's pump-wait and be reported as *its* outcome. The executor mitigates the
+most common instance of this (`CaptureCompletionBaseline`) by running one
+`pumpStep()` immediately before capturing the baseline, so a completion already
+queued for the handle folds into the baseline instead of being available to
+ride the next write's reply; this closes the gap for a callback that arrived
+before the new write started, but a callback that MXAccess queues after that
+pump step and before the COM call returns (or during the wait itself) is still
+indistinguishable from the new write's own completion. Full closure is not
+possible without an MXAccess-side correlation token, which does not exist —
+this is a property of the COM surface, not a gap this worker introduced (a
+native client correlating by handle has the identical ambiguity). The exposure
+is bounded: `statuses` is an enrichment field, and `Hresult`/`ProtocolStatus`
+stay acceptance-only regardless of which completion (if any) was attributed.
+
## COM Creation
The MXAccess analysis source at `C:\Users\dohertj2\Desktop\mxaccess` identifies
diff --git a/src/ZB.MOM.WW.MxGateway.Worker/Ipc/WorkerPipeSession.cs b/src/ZB.MOM.WW.MxGateway.Worker/Ipc/WorkerPipeSession.cs
index a92fa0b..d52f8c4 100644
--- a/src/ZB.MOM.WW.MxGateway.Worker/Ipc/WorkerPipeSession.cs
+++ b/src/ZB.MOM.WW.MxGateway.Worker/Ipc/WorkerPipeSession.cs
@@ -1232,7 +1232,14 @@ public sealed class WorkerPipeSession
_activeCommandTasks.Add(commandTask);
}
- _ = ObserveCommandTaskAsync(commandTask);
+ // WRK-33: every other discarded task in this file is wrapped with ObserveFaultWhenever
+ // (NEXT-04 discipline) so a fault reaching the finalizer unobserved is impossible. This
+ // wrapper task was the one exception — ObserveCommandTaskAsync only swallows
+ // OperationCanceledException, so any other exception escaping ProcessCommandAsync's own
+ // catch path (e.g. a future edit, or a failure past TryWriteFaultAsync's narrow filter)
+ // would fault the discarded task with no observer. Close the gap the same way the rest of
+ // the file does.
+ ObserveFaultWhenever(ObserveCommandTaskAsync(commandTask));
}
private async Task ObserveCommandTaskAsync(Task commandTask)
@@ -1381,11 +1388,18 @@ public sealed class WorkerPipeSession
// the StaHung fault just sent. Without this the heartbeat loop keeps
// advertising a non-faulted state that contradicts the fault.
_state = WorkerState.Faulted;
+ // WRK-34: CommandMethod is a method-name field, not a correlation-id field, so a
+ // consumer reading it (dashboard, gateway logs) shouldn't see a bare correlation id
+ // there. Use a stable label and carry the stuck command's correlation id (if any) in
+ // the diagnostic message instead.
+ string correlationSuffix = string.IsNullOrEmpty(snapshot.CurrentCommandCorrelationId)
+ ? string.Empty
+ : $" Stuck command correlation id: {snapshot.CurrentCommandCorrelationId}.";
await TryWriteFaultAsync(
CreateFault(
WorkerFaultCategory.StaHung,
- snapshot.CurrentCommandCorrelationId,
- $"STA activity is stale by {staleFor}."),
+ "Watchdog",
+ $"STA activity is stale by {staleFor}.{correlationSuffix}"),
cancellationToken).ConfigureAwait(false);
}
diff --git a/src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessCommandExecutor.cs b/src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessCommandExecutor.cs
index 62b4e94..46cbc7e 100644
--- a/src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessCommandExecutor.cs
+++ b/src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessCommandExecutor.cs
@@ -445,7 +445,8 @@ public sealed class MxAccessCommandExecutor : IStaCommandExecutor
// also fire-and-forget in MXAccess, and its commit outcome only exists
// in the later OnWriteComplete callback.
MxAccessWriteCompletionCache completionCache = session.WriteCompletionCache;
- ulong completionBaseline = completionCache.CurrentVersion(
+ ulong completionBaseline = CaptureCompletionBaseline(
+ completionCache,
writeCommand.ServerHandle,
writeCommand.ItemHandle);
@@ -485,7 +486,8 @@ public sealed class MxAccessCommandExecutor : IStaCommandExecutor
// Same pre-call baseline rule as ExecuteWriteSecured.
MxAccessWriteCompletionCache completionCache = session.WriteCompletionCache;
- ulong completionBaseline = completionCache.CurrentVersion(
+ ulong completionBaseline = CaptureCompletionBaseline(
+ completionCache,
write2Command.ServerHandle,
write2Command.ItemHandle);
@@ -523,7 +525,8 @@ public sealed class MxAccessCommandExecutor : IStaCommandExecutor
// immediately after WriteSecured bumps the version past this snapshot,
// so a fast commit still correlates (no missed-callback window).
MxAccessWriteCompletionCache completionCache = session.WriteCompletionCache;
- ulong completionBaseline = completionCache.CurrentVersion(
+ ulong completionBaseline = CaptureCompletionBaseline(
+ completionCache,
writeSecuredCommand.ServerHandle,
writeSecuredCommand.ItemHandle);
@@ -564,7 +567,8 @@ public sealed class MxAccessCommandExecutor : IStaCommandExecutor
// Same pre-call baseline rule as ExecuteWriteSecured.
MxAccessWriteCompletionCache completionCache = session.WriteCompletionCache;
- ulong completionBaseline = completionCache.CurrentVersion(
+ ulong completionBaseline = CaptureCompletionBaseline(
+ completionCache,
writeSecured2Command.ServerHandle,
writeSecured2Command.ItemHandle);
@@ -994,7 +998,31 @@ public sealed class MxAccessCommandExecutor : IStaCommandExecutor
}
///
- /// Bounded pump-wait for the OnWriteComplete row matching a
+ /// Captures the write-completion baseline for /
+ /// immediately before a Write/Write2/WriteSecured/
+ /// WriteSecured2 COM call. Pumps once first (WRK-32) so an OnWriteComplete
+ /// already queued for this handle — most commonly the still-undelivered callback of an
+ /// earlier write to the same tag that this worker gave up waiting on — folds into the
+ /// baseline instead of being available to ride this write's reply.
+ ///
+ ///
+ /// This narrows, but does not close, the correlation gap documented on
+ /// : a completion that MXAccess queues after this pump
+ /// step but before the COM call returns is still indistinguishable from this write's own
+ /// completion, because OnWriteComplete carries no per-call token — only the
+ /// server/item handle pair.
+ ///
+ private ulong CaptureCompletionBaseline(
+ MxAccessWriteCompletionCache completionCache,
+ int serverHandle,
+ int itemHandle)
+ {
+ pumpStep();
+ return completionCache.CurrentVersion(serverHandle, itemHandle);
+ }
+
+ ///
+ /// Bounded pump-wait for the OnWriteComplete row matching a Write/Write2/
/// WriteSecured/WriteSecured2 call, copied onto the reply when it
/// arrives in time. The executor holds the STA thread but pumps
/// Windows messages each poll (ReadBulk precedent) so the COM callback
@@ -1002,6 +1030,21 @@ public sealed class MxAccessCommandExecutor : IStaCommandExecutor
/// statuses — the consumer's unconfirmed path, never a synthesized
/// failure. Protocol status/hresult stay acceptance-only either way.
///
+ ///
+ /// Correlation is recency-based per handle, not per call: MXAccess's
+ /// OnWriteComplete callback carries no correlation token, only the server/item
+ /// handle pair, so this method reports the first completion whose version exceeds
+ /// as this write's outcome. If an earlier write to
+ /// the same handle times out unconfirmed and its callback is still undelivered, that
+ /// stale completion can dispatch during this write's pump-wait and ride this reply
+ /// instead — 's pre-call pump only folds in a
+ /// completion already queued before this write started; it cannot fold in one queued
+ /// during the COM call or the wait itself. The Hresult/ProtocolStatus
+ /// fields stay acceptance-only regardless, so the exposure is limited to the enrichment
+ /// statuses field, and it is inherent to the COM surface — a native client
+ /// correlating by handle has the identical ambiguity. Full closure needs an
+ /// MXAccess-side correlation token, which does not exist.
+ ///
private void AwaitWriteCompletion(
MxCommandReply reply,
MxAccessWriteCompletionCache completionCache,