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[F56] subscribe / subscribe_buffered: split-form wire body + diagnose Galaxy fixture gap

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Three real fixes + one architectural diagnosis:

1. Session::subscribe_buffered_nmx now sends the .NET-reference split
   form on the wire:
     item_definition = "<attr>.property(buffer)"   (was: full reference)
     item_context    = "<object_tag_name>"          (was: empty)
     item_handle     = SessionInner::next_item_handle.fetch_add(1)
                       (was: hardcoded 0)
   Verified byte-identical against captures/082 + 094 by the existing
   buffered_register_reference_parity unit tests. The
   item_handle counter mirrors MxNativeCompatibilityServer's
   _nextItemHandle++ at MxNativeSession.cs:613.

2. New live tests:
   - tests/buffered_subscribe_live.rs (F49 step 1) — uses real Galaxy
     metadata via SqlTagResolver + connect_nmx_auto, drives a
     background writer at 500ms cadence to force value-changes,
     drains DataChange events from Subscription.
   - tests/plain_subscribe_live.rs — same harness over plain
     Session::subscribe (NOT buffered), used to isolate whether
     "no DataUpdate" is buffered-specific (it's not — both fail).

   Both pull tracing-subscriber as a dev-dep so `RUST_LOG=trace`
   surfaces dcom_sink + router activity.

3. mxaccess-galaxy/sql_resolver.rs: drop the inner-attribute
   `#![cfg(feature = "galaxy-resolver")]` — the module-level cfg on
   `pub mod sql_resolver` in lib.rs already handles this and Rust
   1.85's clippy::duplicated_attributes lint flagged the duplicate
   once mxaccess-compat dev-deps activated the feature.

4. F56 finding (diagnosis, NOT a bug fix): the engine on this Galaxy
   install does not have an active value for TestChildObject.TestInt.
   Confirmed by running the .NET reference's own probe:

     dotnet run --project src/MxNativeClient.Probe -c Release \
       -- --probe-session-subscribe --tag=TestChildObject.TestInt \
       --subscribe-hold-seconds=10

   ...returns ONE 0x32 SubscriptionStatus (status=3 detail=3
   quality=0x00C0 Uncertain value=null) and zero 0x33 DataUpdates —
   matching the Rust port's symptom exactly. Not a Rust port bug,
   not a wire-byte gap. F49 steps 1-3 need either an actively-
   scanned tag or local Galaxy reconfiguration to scan
   TestChildObject.TestInt.

Workspace tests + clippy clean under both feature configurations.
F56 entry in design/followups.md updated with the full diagnostic
chain so future-me / future-collaborators can pick it up without
re-tracing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
Joseph Doherty
2026-05-06 10:27:08 -04:00
parent af15fe7587
commit df3457c54a
7 changed files with 276 additions and 82 deletions
Download Patch File Download Diff File Expand all files Collapse all files
rust/crates/mxaccess/src/session.rs
+77 -29
View File
@@ -614,6 +614,18 @@ pub struct SessionInner {
/// dictionaries (`MxNativeSession.cs` field-level comments) plus
/// the ordered list those dictionaries are consulted against.
pub(crate) pending_ops: Arc<Mutex<PendingOps>>,
/// F56 — monotonically-increasing item-handle assigner for
/// `subscribe_buffered`. The .NET reference's
/// `MxNativeCompatibilityServer.AddItem` flow assigns `1, 2, 3, ...`
/// at the LMX layer (`MxNativeCompatibilityServer.cs`) and threads
/// the handle through to the `RegisterReference` wire body.
/// Sending `0` (the previous behaviour) caused the engine to
/// silently swallow the buffered subscription — RegisterReference
/// returned HRESULT 0 + a `0x11` registration result fired, but no
/// `0x33` DataUpdate frames followed. Starting at 1 mirrors the
/// .NET LMX behaviour captured at
/// `captures/094-frida-buffered-separate-writer/frida-events.tsv:13`.
pub(crate) next_item_handle: std::sync::atomic::AtomicI32,
/// F55 / Path A — keeps the DCOM-managed `INmxSvcCallback`'s
/// `IUnknown` ref alive for the session's lifetime. The marshalled
/// OBJREF passed to `RegisterEngine2` references this object's
@@ -841,15 +853,34 @@ pub(crate) async fn callback_router(
// we currently just consume + drop the frame at trace
// level so the catch-all parse below doesn't log a
// spurious "unexpected opcode 0x11" warning.
if let Ok(result) =
NmxReferenceRegistrationResultMessage::try_parse_process_data_received_body(&body)
{
tracing::trace!(
item_handle = result.item_handle,
correlation_id = ?result.item_correlation_id,
"callback_router: 0x11 RegistrationResult received"
);
continue;
match NmxReferenceRegistrationResultMessage::try_parse_process_data_received_body(
&body,
) {
Ok(result) => {
tracing::trace!(
item_handle = result.item_handle,
correlation_id = ?result.item_correlation_id,
item_definition = %result.item_definition,
item_context = %result.item_context,
status_category = result.status_category,
status_detail = result.status_detail,
"callback_router: 0x11 RegistrationResult received"
);
continue;
}
Err(e) => {
let hex: String = body
.iter()
.map(|b| format!("{b:02x}"))
.collect::<Vec<_>>()
.join(" ");
tracing::trace!(
err = %e,
body_len = body.len(),
body_hex = %hex,
"callback_router: not a 0x11 RegistrationResult, falling through"
);
}
}
// 3. Fall through to subscription messages. Wire bytes
@@ -1107,6 +1138,7 @@ impl Session {
callback_obj_ref,
rebuild_factory: Mutex::new(None),
pending_ops,
next_item_handle: std::sync::atomic::AtomicI32::new(1),
#[cfg(all(windows, feature = "windows-com"))]
dcom_sink_holder: Mutex::new(dcom_sink_holder),
}),
@@ -1935,25 +1967,36 @@ impl Session {
.map_err(map_resolver)?;
let correlation_id: [u8; 16] = rand::random();
// Build the buffered RegisterReference body. Item definition is
// the full reference suffixed with `.property(buffer)`; item
// context is empty for this single-string form (the .NET
// reference's split-context form is reachable via the
// compat-server layer F35 once it lands). The codec helper
// rejects empty/whitespace inputs with `CodecError::InvalidName`.
let item_definition = NmxReferenceRegistrationMessage::to_buffered_item_definition(
reference,
)
.map_err(|e| {
Error::Configuration(ConfigError::InvalidArgument {
detail: format!("buffered item definition: {e}"),
})
})?;
// F56 — build the buffered RegisterReference body in the split
// (object, attribute) form the .NET reference uses on the wire:
// item_definition = "<attribute>.property(buffer)"
// item_context = "<object_tag_name>"
// item_handle = sequential per-session counter starting at 1
//
// The previous implementation used the single-string form (full
// reference in `item_definition`, empty `item_context`,
// `item_handle = 0`). RegisterReference returned HRESULT 0 and
// the engine fired a `0x11` registration result, but **no
// `0x33` DataUpdate frames ever followed** — confirmed live
// 2026-05-06. Switching to the split form mirrors the captured
// .NET wire bytes at
// `captures/094-frida-buffered-separate-writer/frida-events.tsv:23`
// (the PutRequest body at 21:40:19.970).
let item_handle = inner
.next_item_handle
.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
let attribute_only_definition =
NmxReferenceRegistrationMessage::to_buffered_item_definition(&metadata.attribute_name)
.map_err(|e| {
Error::Configuration(ConfigError::InvalidArgument {
detail: format!("buffered item definition: {e}"),
})
})?;
let registration = NmxReferenceRegistrationMessage {
item_handle: 0,
item_handle,
item_correlation_id: correlation_id,
item_definition,
item_context: String::new(),
item_definition: attribute_only_definition,
item_context: metadata.object_tag_name.clone(),
subscribe: true,
reserved_25_27: [0; 2],
reserved_31_55: [0; 24],
@@ -1996,9 +2039,13 @@ impl Session {
metadata: Arc::clone(&metadata_arc),
mode: SubscriptionMode::Buffered {
rounded_interval_ms: rounded_ms,
item_definition: reference.to_string(),
item_context: String::new(),
item_handle: 0,
// F56 — recovery replays via `register_reference` and
// must reissue the same wire body. Save the split
// (object, attribute, handle) triple, NOT the
// pre-F56 single-string form.
item_definition: registration.item_definition.clone(),
item_context: registration.item_context.clone(),
item_handle,
},
},
);
@@ -2554,6 +2601,7 @@ mod tests {
callback_obj_ref: Vec::new(),
rebuild_factory: Mutex::new(None),
pending_ops,
next_item_handle: std::sync::atomic::AtomicI32::new(1),
#[cfg(all(windows, feature = "windows-com"))]
dcom_sink_holder: Mutex::new(None),
}),