7b6ab2ec6f
Core.Scripting-008 resolution: replace the legacy CSharpScript.CreateDelegate
path with hand-rolled CSharpCompilation + Emit + collectible AssemblyLoadContext,
so per-publish compile accretion no longer requires a server restart to reclaim.
Why this was needed:
Roslyn's CSharpScript path emits dynamically-compiled script assemblies into
the default AssemblyLoadContext, which is non-collectible. Across config-
publish generations each Clear() drops dictionary entries but the emitted
assemblies stay loaded for process lifetime, so memory grows steadily on
long-running servers with frequent publishes. The accepted-limitation note
in docs/VirtualTags.md recommended scheduled restarts as the workaround;
operator feedback was that restarts are difficult, so the underlying
limitation was the right thing to fix.
Implementation:
- New ScriptAssemblyLoadContext(name, isCollectible: true) hosts one emitted
script assembly per evaluator.
- ScriptEvaluator.Compile synthesises a wrapper class around the user source
(CompiledScript.Run(globals) — explicit return required per ordinary C#
semantics, which every existing script already uses), builds a
CSharpCompilation against the sandbox references, runs the
ForbiddenTypeAnalyzer over the semantic model unchanged, emits to an
in-memory PE stream, loads via ScriptAssemblyLoadContext.LoadFromStream,
and binds a strongly-typed Func<ScriptGlobals<TContext>, TResult> delegate
via reflection.
- ScriptEvaluator now implements IDisposable — Dispose calls
AssemblyLoadContext.Unload(), which makes the emitted assembly eligible
for GC at the next collection cycle.
- CompiledScriptCache.Clear() disposes every materialised evaluator before
dropping its dictionary entry; CompiledScriptCache itself is now
IDisposable for graceful server shutdown.
- ScriptSandbox.Build returns a new SandboxConfig (References + Imports)
instead of a Roslyn ScriptOptions; references now span BCL via the
TRUSTED_PLATFORM_ASSEMBLIES set filtered to System.* + netstandard +
Microsoft.Win32.Registry, so forbidden BCL types resolve at compile and
ForbiddenTypeAnalyzer is the sole security gate (consistent with the
Core.Scripting-001 / -002 model — references-list-only restriction is
porous against type forwarding, so the analyzer must be the real gate).
Verification:
- All 104 Core.Scripting tests pass (was 101 — three new regression tests
locking the unload contract).
- All 56 VirtualTags tests pass (unchanged).
- All 63 ScriptedAlarms tests pass (unchanged).
- New CompiledScriptCacheTests:
- Dispose_unloads_compiled_script_assembly_load_context — proves single-
evaluator ALC unload via WeakReference + bounded GC.Collect() loop.
- Clear_disposes_every_materialised_evaluator — proves publish-replace
releases every prior generation's ALC.
- GetOrCompile_after_Dispose_throws_ObjectDisposedException — locks the
post-dispose contract.
Docs:
- docs/VirtualTags.md "Compile cache" section rewritten: the accepted-
limitation note replaced with the unload contract + the new authoring
convention (explicit return).
- docs/ScriptedAlarms.md cross-reference updated to drop the obsolete
restart guidance.
- code-reviews/Core.Scripting/findings.md Core.Scripting-008 flipped
Won't Fix → Resolved with the implementation summary.
- code-reviews/README.md regenerated.
Pre-existing breakage note: Driver.Galaxy fails the solution-wide build on
master because its ProjectReference to the sibling mxaccessgw repo's
MxGateway.Client targets a path that the sibling repo no longer has after a
recent restructuring. This is unrelated to Core.Scripting-008 and was
verified to exist on master before this branch was cut.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
OtOpcUa
OPC UA server (.NET 10 AnyCPU) that exposes a fleet of industrial drivers as a single OPC UA address space. Drivers ship in-process for AVEVA System Platform Galaxy (via the sibling mxaccessgw repo), Modbus TCP, Siemens S7, Allen-Bradley CIP (ControlLogix / CompactLogix), Allen-Bradley Legacy (SLC 500 / MicroLogix), Beckhoff TwinCAT (ADS), FANUC FOCAS, and OPC UA Client (gateway).
A cross-platform client stack (.NET 10) — shared library, CLI, and Avalonia desktop app — connects to any OPC UA server.
Architecture
OPC UA Clients (CLI, Desktop UI, 3rd-party)
|
v
+-------------------------------------+
| OtOpcUa.Server (.NET 10 AnyCPU) |
| address space + capability fan-out|
+-------------------------------------+
| | | | | | | |
Galaxy Modbus S7 AbCip AbLeg TwinCAT FOCAS OpcUaClient
|
v
mxaccessgw (sibling repo, gRPC)
|
v
MXAccess COM (x86 worker, on AVEVA box)
Galaxy is the only driver with an external runtime: it speaks gRPC to a separately installed mxaccessgw server (sibling repo at c:\Users\dohertj2\Desktop\mxaccessgw\) which owns the MXAccess COM apartment and the x86/STA bitness constraint server-side. Everything in this repo is platform-agnostic .NET 10.
Prerequisites
- .NET 10 SDK (server, drivers, clients all target .NET 10)
- SQL Server reachable for the central config DB
- For Galaxy specifically: a running
mxaccessgwdeployment — see docs/v2/Galaxy.ParityRig.md - For Wonderware Historian read-back: optional
OtOpcUaWonderwareHistoriansidecar — see docs/ServiceHosting.md
Quick Start
dotnet restore ZB.MOM.WW.OtOpcUa.slnx
dotnet build ZB.MOM.WW.OtOpcUa.slnx
dotnet test ZB.MOM.WW.OtOpcUa.slnx
# Run the server in dev (foreground)
dotnet run --project src/Server/ZB.MOM.WW.OtOpcUa.Server
The server starts on opc.tcp://localhost:4840 with the None security profile. Configure Security.Profiles in src/Server/ZB.MOM.WW.OtOpcUa.Server/appsettings.json to enable Basic256Sha256-Sign or Basic256Sha256-SignAndEncrypt. See docs/security.md.
Install as Windows Services
Production deployment is driven by scripts/install/Install-Services.ps1, which registers the OtOpcUa server service (and optionally the OtOpcUaWonderwareHistorian sidecar) under a chosen service account. Galaxy support requires a separately installed mxaccessgw — neither this repo nor the install script provisions it.
.\scripts\install\Install-Services.ps1 `
-InstallRoot 'C:\Program Files\OtOpcUa' `
-ServiceAccount 'DOMAIN\svc-otopcua'
Add -InstallWonderwareHistorian for the historian sidecar. See the script header and docs/ServiceHosting.md for full options.
Client CLI
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- connect -u opc.tcp://localhost:4840
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- browse -u opc.tcp://localhost:4840 -r -d 3
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- read -u opc.tcp://localhost:4840 -n "ns=2;s=SomeNode"
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- write -u opc.tcp://localhost:4840 -n "ns=2;s=SomeNode" -v 42
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- subscribe -u opc.tcp://localhost:4840 -n "ns=2;s=SomeNode" -i 500
See docs/Client.CLI.md and docs/Client.UI.md.
Documentation
Architecture deep-dives
| Topic | Doc |
|---|---|
| OPC UA server composition, namespace fan-out, Polly invoker | docs/OpcUaServer.md |
| Address space layout | docs/AddressSpace.md |
| Read / Write dispatch (driver vs virtual vs scripted-alarm) | docs/ReadWriteOperations.md |
| Incremental sync (driver-backend rediscovery + config publishes) | docs/IncrementalSync.md |
| Service hosting (Server + Admin + optional historian sidecar) | docs/ServiceHosting.md |
| Security (transport, LDAP, certificates) | docs/security.md |
| Redundancy | docs/Redundancy.md |
| Status dashboard | docs/StatusDashboard.md |
Drivers
| Topic | Doc |
|---|---|
| Driver specs (per-driver capability surface, config, addressing) | docs/v2/driver-specs.md |
| Galaxy driver | docs/drivers/Galaxy.md |
| Modbus / S7 / AbCip / AbLegacy / TwinCAT / FOCAS / OpcUaClient | docs/drivers/ |
| Galaxy parity rig (mxaccessgw setup) | docs/v2/Galaxy.ParityRig.md |
| Galaxy performance + tracing | docs/v2/Galaxy.Performance.md |
Clients
| Topic | Doc |
|---|---|
| Client CLI | docs/Client.CLI.md |
| Client UI (Avalonia desktop) | docs/Client.UI.md |
v1 archive
The original v1 in-process MXAccess docs (Galaxy.Host topology, Configuration env vars, AlarmTracking, DataTypeMapping, HistoricalDataAccess, Subscriptions, etc.) are preserved under docs/v1/ — historical reference only. PR 7.2 retired the v1 architecture on 2026-04-30; current state is documented in the sections above.
License
Internal use only.