Joseph Doherty
1a1830f3bf
Mirrors the .NET reference's `if (!subscription.IsBuffered)` guard
at `MxNativeSession.cs:361-381`. The Rust port previously emitted an
`UnAdvise` frame for both plain and buffered subscriptions; the
buffered server-side registration is unwound by the engine when the
`RegisterReference` handle goes away, so emitting an `UnAdvise` for
buffered entries is at best a no-op extra frame and at worst could
race with the engine's own teardown.
Fix: branch `Session::unsubscribe` on `SubscriptionEntry::mode` (the
discriminator F45 added). For `SubscriptionMode::Buffered { ... }`,
skip the `un_advise` call and proceed directly to registry cleanup.
For `SubscriptionMode::Plain`, retain the previous behaviour.
The registry-entry probe runs first (separate lock acquisition) so
the `is_buffered` decision doesn't hold the NMX-client mutex
unnecessarily — common case where the entry is plain still acquires
the NMX lock immediately after.
The metrics counter `record_unadvise()` still fires on every public
`unsubscribe` call regardless of mode — it tracks consumer-side
unsubscribe rate, not wire-frame rate. That matches what dashboards
expect from the public API.
New unit test `unsubscribe_skips_un_advise_for_buffered_subscription`
issues a plain subscribe (recorded as 1 RPC), mutates the registry
entry to `SubscriptionMode::Buffered`, calls unsubscribe, and
asserts the recorded RPC count stays at 1 (no UnAdvise emitted).
The existing `subscribe_populates_registry_unsubscribe_clears_it`
test serves as the negative control for the plain branch.
Workspace 794 → 795 tests; clippy clean; rustdoc clean.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
mxaccess (Rust port)
Native Rust replacement for AVEVA / Wonderware MXAccess. See ../design/ for
the architectural specification, ../src/ for the .NET reference (the
executable spec), and ../CLAUDE.md for project-wide rules.
Status
M0 — Workspace skeleton. Stub types compile; nothing is implemented yet.
See ../design/60-roadmap.md for the M0–M6 milestone plan.
Layout
rust/
Cargo.toml workspace root
rust-toolchain.toml 1.85 stable
crates/
mxaccess-codec/ pure protocol codec, no I/O
mxaccess-galaxy/ Galaxy SQL resolver (tiberius)
mxaccess-rpc/ DCE/RPC + NTLMv2 + OXID + OBJREF
mxaccess-callback/ INmxSvcCallback RPC server
mxaccess-nmx/ INmxService2 client
mxaccess-asb-nettcp/ net.tcp framing (MC-NMF + MC-NBFX/NBFS)
mxaccess-asb/ IASBIDataV2 client
mxaccess/ async session + Transport trait + public API
mxaccess-compat/ LMXProxyServer-shaped facade
Build
cargo build --workspace
cargo test --workspace
cargo clippy --workspace -- -D warnings
cargo fmt --check
Live probes
. ..\tools\Setup-LiveProbeEnv.ps1
cargo test -p mxaccess --features live -- --ignored
The setup script fetches credentials from Infisical via
wwtools/secrets/Get-Secret.ps1. Never inline plaintext credentials.
License
MIT — see ../LICENSE.