The centerpiece of the whole "no domain reload" claim, now proven
empirically rather than argued on paper: 200 load/unload cycles against
a real plugin (sandbox.echo), each one checked with a WeakReference
that the collectible ALC actually collected — docs/kernel-contract.md
§4's leak test, previously Skip-marked since the very first scaffold,
now runs and passes (stable across repeated runs).
New pieces, minimal by design:
- PluginLoadContext: the collectible ALC a plugin's implementation
loads into. Load() defers to whatever's already in the Default ALC
(Engine.Kernel, the plugin's own Contracts assembly) before
consulting AssemblyDependencyResolver for genuinely private
dependencies — the standard .NET plugin pattern, needed so component
types stay identical across the plugin boundary instead of loading
as two distinct, incompatible copies.
- PluginHost: reads plugin.json, loads Contracts into the Default ALC
(once — verified directly, not just inferred from the leak test),
loads the implementation into a fresh PluginLoadContext, finds the
IPlugin type via reflection, calls Configure(). Unload() calls
Shutdown() first, then .Unload()s the ALC and hands back a
WeakReference for the caller to check.
- Schedule, ServiceRegistry, NullEventBus, ConsoleLogger: minimal real
implementations of the remaining IPluginContext pieces — no stage
execution or parallelism in Schedule yet, that's separate Scheduler
work. Schedule.RemoveAllFrom is the one piece that has to be
correct now, not later: it's what lets a plugin's Shutdown() actually
drop the delegate reference into its own collectible ALC, which is
exactly what the leak test is checking end to end.
Explicitly out of scope for this pass: resolving a project's or
plugin's dependsOn graph to order loading across multiple plugins.
Nothing to test that against yet — sandbox.echo is deliberately the
only, dependency-free fixture. Noted as a TODO on PluginHost rather
than built speculatively.
Sandbox.Echo.csproj gets <EnableDynamicLoading>true</EnableDynamicLoading>
(future plugins with real dependencies will need the deps.json this
generates). Engine.ConformanceHarness.csproj now copies plugin.json and
both built DLLs into one flat directory under its own output, matching
the layout PluginHost.Load(directory) expects — via $(Configuration)/
$(TargetFramework)-aware CopyToOutputDirectory items, correct in
Release too, not just Debug.
17 tests total now (13 in Engine.Kernel.Tests, 4 in
Engine.ConformanceHarness), all passing on a clean build.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N
First real piece of M0 rather than scaffolding. GameWorld : IWorld owns
GameObject creation/destruction, a type-indexed Dictionary<Type,
HashSet<GameObject>> backing Query<T>(), and hierarchy bookkeeping
(roots list, parent/children, cycle rejection on SetParent).
Two corrections to the design doc found while implementing:
- WorldMatrix can't be cached on Transform as described — Transform is
a plain struct with no reference to the hierarchy it would need to
compose against. Moved to GameObject.WorldMatrix, computed from the
parent chain on read; docs/kernel-contract.md and the §3 example
updated (go.Transform.WorldMatrix -> go.WorldMatrix).
- The concrete World class collided with its own containing namespace
(Engine.Kernel.World.World), which makes the bare name ambiguous for
every consumer. Renamed to GameWorld; IWorld and the World folder/
namespace are unaffected, and the doc never named the concrete class
either way, so nothing there needed to change.
Also fixed a real correctness bug caught while writing World.Destroy:
a GameObject can carry more than one component of the same type, so
removing one from the type index has to check whether any others of
that type remain before dropping the GameObject from the index set —
tested directly (Query_Still_Finds_A_GameObject_With_A_Duplicate_
Component_After_One_Removal).
12 tests in Engine.Kernel.Tests cover creation, hierarchy (including
cycle rejection), component add/remove/query, destroy cascading
through a subtree, and WorldMatrix composition (verified against a
worked-through parent+child translation, not just asserted).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N
Buildable skeleton matching docs/kernel-contract.md:
- src/Engine.Kernel — the frozen kernel. Interfaces and data types only
(World, Component, GameObject, Transform, ISchedule, IServiceRegistry,
IEventBus, ILogger, IPlugin/IPluginContext, plugin.json and project.json
manifest models). No PluginHost/Scheduler/World implementation yet —
that's M0's actual work, not scaffolding.
- src/Engine.Host — the CLI runtime entry point, placeholder for now.
- plugins/sandbox.echo — a minimal two-assembly plugin (Contracts in
Default ALC, implementation in collectible ALC) that exists only to
exercise the reload loop end to end once PluginHost exists.
- tests/Engine.Kernel.Tests, tests/Engine.ConformanceHarness — wired up
with one Skip-marked placeholder test each, naming what M0 needs to
make them real (including the 200-cycle ALC leak test from §4). The
harness references the sandbox plugin with
ReferenceOutputAssembly="false" so it loads it dynamically by path
instead of linking its types into its own Default ALC.
- samples/EmptyProject — a starter project.json.
- Directory.Build.props centralizes shared settings across every
project, including AllowUnsafeBlocks=false to enforce the §7 rule at
the build level rather than by convention.
Solution builds clean and `dotnet test` runs both placeholders as
Skipped (not failing) — confirms the wiring, not the engine.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N
Surfaces the constraint that already shapes several kernel decisions
(GameObject/Component over ECS, explicit registration, the headless
introspection surface) instead of leaving it only in the internal spec.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N
- Restore scheduler parallelism (dropped by accident in the ECS ->
GameObject/Component rewrite; nothing about the object model
actually prevents parallel execution of systems with disjoint
declared access), plus the structural-change queuing that makes
that safe.
- Rename leftover ECS-era `Entity` references to `GameObject`.
- Add per-project plugin configuration (project.json): the doc had no
mechanism backing the "configurable per project" requirement, even
though the README already claimed it.
- State the indie/small-team scope explicitly — it's the unstated
premise behind several tradeoffs already in the doc (GC, GameObject
over ECS, no custom RHI).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N
Match the more familiar Unity-style object model instead of a
struct-of-arrays ECS: GameObject hierarchy with type-indexed component
queries, Transform inlined as the one performance-motivated exception.
Data/behavior stay split the same way ECS required it, so hot-reload
safety is unaffected.
Also fixes an inconsistency in the previous reload sequence, which
described migrating live component data on a contract change even
though the Default ALC hosting contracts never unloads. Contract
changes now explicitly require an editor restart instead.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N
Lay out the design that everything else builds on: a small frozen
kernel plugins treat as a shared language, the plugin contract, the
two-assembly hot-reload model, and the build order through M4.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N
