## Summary
Phase 3 of the anchored-time work: **every actively-written delta-time value in the engine now stores an anchored timestamp** — absolute on the wire, shifted forward by the downtime at load. Remaining time survives restarts (as delta did), and unlike delta, the bytes do not change on every save, so an idle world serializes identically save after save.
The answer to "is it possible everywhere": **yes** — including the one case that looked impossible.
## The GenericPersistence problem, solved
`GenericPersistence` bins (`Virtues.bin`, `StealableArtifacts.bin`, …) are raw payloads with no idx header, so they have no anchor of their own — anchored reads there would silently apply zero shift. But the anchor is a property of the **save**, not the file: every file in one save shares one `World.SaveStartTime`, and `Persistence.Load` reads **all** entity indexes (phase 1) before **any** persistence payload (phase 2). So the idx v5 header stamps a save-wide `World.LoadTimeShift`, and generic persistence readers inherit it. No file-format change, no per-bin header, old bins unaffected.
## Converted
- **Item v10 → v11**: `LastMoved` — previously whole-minute delta, rewritten every save for every item, the single largest source of idle-save churn — and `DecayResetTime` (retiring the TODO from #2583). **Mobile v37 → v38**: the three stat-gain stamps. **BaseCreature v20 → v21**: `SummonEnd`.
- **17 code-generated classes** (`[DeltaDateTime]` → `[AnchoredDateTime]`, version bump + `MigrateFrom` each): the five field spells, TransientItem, VirtueContext (×7 fields), PuzzleChestSolutionAndTime, BaseCamp, BaseBoat, RentedVendor, PlayerVendor, Ethics Player, Sheep, StarRoomGate, ChampionSpawn (×3), Corpse (`TimeOfDeath`, v19). The `MigrateFrom` bodies were generated from each class's current migration schema and are compiler-verified; VirtueContext's save-flagged nullables fall back to the same defaults the old deserialize left in place. Corpse's six migrations moved to a new `Corpse.Migrations.cs`.
- **Hand-written sites**: StealableArtifacts (v2), VendorInventory (v1), ML quest objectives (persistence v3) — each gated on its own version.
**Not converted, deliberately**: the ~25 read-only `ReadDeltaTime` sites in legacy version fallbacks and migration replays — they decode existing old bytes and must never change. `[DeltaDateTime]`/`WriteDeltaTime` remain available for them.
## Verification
- Build 0 errors / 0 warnings; **837 + 708 tests green**.
- Schema regeneration produced exactly the 17 expected new `vN.json` files (all `AnchoredTime` rule args), nothing else touched.
- **New acceptance tests** pin the point of the whole effort: serializing the same item at two save times **5 hours apart produces byte-identical output**, and `LastMoved`/`DecayResetTime` round-trip **exactly** at sub-minute precision (the old minutes encoding destroyed both properties).
## Notes for review
- `LastMoved` grows from a 1–3 byte encoded minutes value to 8-byte ticks per item — the price of byte-stability; it repays itself in incremental-save behavior since unchanged items now produce unchanged bytes.
- BaseEscortable-style semantics are unchanged: anchored shift preserves *remaining* time exactly, the same contract delta provided, so no gameplay-visible behavior changes — deadlines simply stop being consumed by downtime that delta already protected against, now with stable bytes.
## Enforcement
`WriteDeltaTime` is now `[Obsolete]` (interface + implementation). With the repo's warnings-as-errors, any new delta-time write — hand-written or emitted by a still-unconverted `[DeltaDateTime]` field — fails the build, with the migration instructions in the message. That the full solution still builds with **zero warnings** is itself the proof no active delta writer survived the conversion. `ReadDeltaTime` deliberately stays un-attributed: its remaining callers decode existing old bytes and are correct forever; its XML docs now state the legacy-decode-only contract.
## Summary
Folds **113** hand-written `[SerializableProperty]` members into plain `[SerializableField]` declarations using the v4 setter hooks — value coercion/vetoes via `allowFieldChange`, post-change side effects via `fieldChanged` (whose `oldValue` parameter covers the old-house/old-sender unsubscribe patterns). Net **-450 lines** of setter boilerplate.
```cs
// before
[SerializableProperty(1)]
[CommandProperty(AccessLevel.GameMaster)]
public int Charges
{
get => _charges;
set
{
_charges = Math.Clamp(value, 0, MaxCharges);
InvalidateProperties();
this.MarkDirty();
}
}
// after
[SerializableField(1, allowFieldChange: nameof(AllowChargesChange))]
[SerializedCommandProperty(AccessLevel.GameMaster)]
[InvalidateProperties]
private int _charges;
private bool AllowChargesChange(ref int value)
{
value = Math.Clamp(value, 0, MaxCharges);
return true;
}
```
## How sites were selected
A classifier parsed all 204 `[SerializableProperty]` sites and converted only those matching strict shapes: getter is exactly `get => _field;`, the assignment comes first (after at most an equality guard), and relocated side effects contain no `return`, no `value` mutation, and no field re-assignment. Everything else was left alone deliberately:
- **~34 custom getters** (fallback defaults like `_x == -1 ? Default : _x`, self-healing refs) — no setter hook can express these.
- **~35 pre-assignment logic** (durability Unscale/Scale sandwiches, old-state captures like PotionKeg's pile weight).
- **virtual/override members, name-mismatched backing fields (`m_`), exotic semantics** (guards' `Focus` does work on *equal* assignment; `ChampionSpawn.Active` never assigns its field).
Five sites the classifier refused were converted by hand where the hooks fit cleanly: `ReceiverCrystal.Sender`, `PlayerVendor.House`, `PlayerBarkeeper.House` (old-value unsubscribe via `oldValue`), `BaseSuit.AccessLevel` (its existing virtual `OnAccessLevelChanged` already had the exact callback shape), and `DyeTub.DyedHue` (a true veto: `AllowDyedHueChange(ref int value) => _redyable`).
## Verification
- Build: **0 errors, 0 warnings**.
- **Schema regeneration produces zero Migrations changes** — the conversion is wire- and schema-neutral by construction (same orders, types, and property names), and CI's schema diff check enforces it.
- **835 + 708 tests green.**
## Behavioral notes (all strict improvements, called out for review)
- Generated setters skip everything when the incoming value equals the current one; a few converted setters previously re-ran side effects on equal assignment (redundant `Update()`-style refreshes).
- Generated setters always `MarkDirty()` on change; several converted setters never did (e.g. `DyeTub.DyedHue`, `MorphItem` ranges) — their changes only persisted if something else dirtied the entity. Those latent persistence bugs are fixed by construction.
## Summary
Adopts ModernUO.Serialization 4.0.0 across the engine. Three commits, reviewable independently:
1. **Package + tool bump to 4.0.0** (`Server.csproj`, `UOContent.csproj`, `dotnet-tools.json`).
2. **Timers → `[DeserializeTimer]`** — the 8 drifting timers (BaseLight, TreasureMapChest, MarkContainer, FillableContainer, DeathRobe, DecayedCorpse, Corpse, BaseEscortable) now store their next tick as **anchored time**: server downtime no longer consumes the remaining delay, and idle-world saves are byte-stable. This changes their wire format, so each class bumps its serialization version with a `MigrateFrom` that replays the old delta-time read through the migration schema (the new `vN.json` files carry `@AnchoredTimer`; the old ones keep `@TimerDrift`, which the generator reads forever). The 2 wall-clock timers (Aquarium, FountainOfLife) keep their exact format via `wallClock: true` — no bump. Restart methods drop their `TimeSpan.MinValue` sentinel checks: v4 invokes them **only when a timer was actually running at save**.
3. **Linkage → field-side declarations** — 175 conversions across 25 files: `[SerializableFieldSaveFlag(order)]`/`[SerializableFieldDefault(order)]` become `[SaveFlag(nameof(...), nameof(...))]` on the field, and `[SerializableFieldChanged(order)]` becomes the `fieldChanged:` argument of `[SerializableField]`. **Wire-neutral: zero migration schemas changed.**
## Verification
- Solution builds with **0 errors, 0 warnings**; all three 4.0.0 packages verified indexed on nuget.org (no local feed needed).
- **835 + 708 tests green.**
- Generated output inspected: old-version content structs replay `ReadDeltaTime` (e.g. `V3Content.DecayTimerNext = reader.ReadDeltaTime()`), current versions write/read anchored time with the gated restart, and the wall-clock classes emit byte-identical `Write`/`ReadDateTime` framing.
- Schema tool run is committed (CI's `git diff --exit-code` schema check passes): exactly the 8 expected new `vN.json` files, nothing else touched.
- The conversion was scripted with a class-scoped resolver (order → same-class `[SerializableField(order)]`/`[SerializableProperty(order)]`); it planned 175/175 with zero ambiguities before applying.
## Notes
- New `MigrateFrom`s use the content structs' provided `XxxDelay` property, matching the pre-existing idiom in Corpse's and TreasureMapChest's older migrations.
- Follow-up candidate (separate PR, wire-neutral, any time): fold the ~150 eligible hand-written `[SerializableProperty]` setters (clamps, post-change side effects) down to `[SerializableField]` with `allowFieldChange`/`fieldChanged` hooks.
### Summary
* Removes player constructed as a requirement for BODs.
* When two items stack and they don't match player constructed flags, the resulting stack loses the flag.
Follow-up to #2573. That change made `SmallBOD.EndCombine` require a player-crafted item, but it could only read provenance off `BaseArmor`, `BaseWeapon` and `BaseClothing`, because those are the only three classes that track it — hence the hand-enumerated `armor?.PlayerConstructed ?? clothing?.PlayerConstructed ?? weapon?.PlayerConstructed ?? false`.
The gap is structural rather than cosmetic. `PlayerConstructed` is set inside each base's `OnCraft`, so it can only ever reach types implementing `ICraftable`. Most craftables do not — the tinkering catalogue alone is largely plain `Item` subclasses — so any rule keyed on "was this actually crafted" has nothing to key on for those types.
## What changed
Provenance moves to `Item` and is stamped centrally in `CraftItem`, immediately after the item is constructed and before the `ICraftable` dispatch, covering both the AOS and T2A craft paths. The three `OnCraft` overrides drop their now-redundant assignment and inherit `Item`'s property, so no call site outside them changes — `Resmelt` and `SalvageBag` still read `armor.PlayerConstructed` and still compile unchanged. `SmallBOD`'s three-way null-coalescing chain collapses to `item.PlayerConstructed`.
`OnCraft` is only ever invoked from `CraftItem` (the other three call sites are `base.OnCraft` chaining), so removing those assignments has no other reachable effect.
## Storage cost: none
`Item`'s `SaveFlag` word is written as a fixed-width `int`, not an encoded one, so occupying bit `0x08000000` changes no record lengths. Items that are not player-constructed serialize byte for byte as before, and crafted ones differ by a single bit in a field already being written.
`Item` itself needs no version bump: a bare `SaveFlag` bit is self-describing, so records written before it existed lack it and read `false`.
## Version bumps
The three content classes do need one, since removing a serialized field changes their layout:
| Class | Version | Field removed |
|---|---|---|
| `BaseArmor` | 9 → 10 | 24 (was last, nothing renumbered) |
| `BaseClothing` | 7 → 8 | 7 (fields 8–10 shift down) |
| `BaseWeapon` | 10 → 11 | 26 (fields 27–30 shift down) |
Each gets a `MigrateFrom` for its previous version that assigns the old bool to the inherited property, so existing crafted armour, weapons and clothing keep their provenance across the upgrade. `Item.Deserialize` runs first and reads the absent bit as `false`, then the migration overwrites it — the generated `Deserialize` calls `base.Deserialize` before dispatching, so the ordering holds. `BaseWeapon` had no migrations file and gains one.
The renumbering is not stylistic: the generator requires contiguous field ordering and rejects a hole with `SG3005: Expected field 'Crafter' with order 7 but found 8`.
New schema JSONs (`BaseArmor.v10`, `BaseClothing.v8`, `BaseWeapon.v11`) are generated by `ModernUOSchemaGenerator` and committed alongside.
## One thing worth a second opinion
The new property is a plain auto-property on `Item`, so it does not call `this.MarkDirty()` the way the codegen setters it replaces did. `MarkDirty` is currently a no-op (`// TODO: Add dirty tracking back`) and no property in `Item.cs` calls it, so this matches the file as it stands — but it is worth noting if dirty tracking comes back.
## Verification
Full solution builds in Release with 0 errors and 0 warnings; 1516 tests pass (815 `Server.Tests`, 701 `UOContent.Tests`).
## Problem
`SmallBOD.EndCombine` validates an item's **type**, **material** and **exceptional quality**, but never checks that the item was actually crafted by a player. Any item matching the request is accepted, including one bought straight from an NPC vendor.
https://github.com/modernuo/ModernUO/blob/main/Projects/UOContent/Engines/Bulk%20Orders/SmallBOD.cs#L117-L168
Where a vendor stocks a type a BOD can request, a player can fill the deed by buying the items instead of crafting them, and pocket the reward gold for the difference.
Tailoring is the clearest case. `SmallTailorBOD.CreateRandomFor` guarantees `Material = None` and `RequireExceptional = false` below 70.1 skill, so the rolled deed asks for plain cloth items — and tailor vendors stock several of those directly. A qty-20 Bandana BOD can be filled entirely from vendor stock for a small fraction of the reward gold, with no crafting and no material cost.
The same shape applies anywhere else a vendor-sold type overlaps a requestable BOD type; tailoring is simply where the low-skill deed generator and the vendor inventory overlap most.
## Fix
Add a `PlayerConstructed` check alongside the existing material and quality checks.
```csharp
var playerConstructed = armor?.PlayerConstructed ?? clothing?.PlayerConstructed ??
weapon?.PlayerConstructed ?? false;
if (!playerConstructed)
{
from.SendLocalizedMessage(1045169); // The item is not in the request.
}
```
This follows the pattern already used in `Engines/Craft/Core/Resmelt.cs` (L98-L100, L155-L160) to distinguish crafted from store-bought items, and reuses the same null-coalescing chain style as the adjacent `GetMaterial(armor?.Resource ?? clothing?.Resource ?? CraftResource.None)` line directly above it.
`PlayerConstructed` is already set in `OnCraft` and serialized on all three bases (`BaseArmor`, `BaseWeapon`, `BaseClothing`), so the flag survives restarts and no serialization change is needed.
## Open question — the message
There is no dedicated cliloc for "this item must be crafted", so I reused **1045169** (*"The item is not in the request."*). It is arguably accurate — a vendor-bought item genuinely is not what the deed asked for — but it is not precise, and a player who does not know the rule will find it confusing.
I would rather flag this than invent a string. If there is a better cliloc, I am happy to switch it.
## Testing
`dotnet build Projects/UOContent/UOContent.csproj` — **0 errors, 0 warnings**.
Not covered: I have not added an automated test, as I could not find existing coverage for `EndCombine` to extend. Happy to add one if you would like it, with a pointer to the preferred pattern.
## Compatibility note
Any *already-existing* vendor-bought item in a player's possession will now be rejected by a BOD. That is the intended behaviour, but it is a visible change for anyone mid-deed. Worth a line in release notes.
## Why
An Argon2 verify is **~8.9 ms of frozen world per login attempt** — more than half a 16 ms frame. Failed attempts cost exactly the same as successful ones, by design, so a credential-stuffing flood is a full-cost stall per packet without needing valid credentials. `SetPassword` derives a hash too, so `[password`, the admin gump and account creation each pay the same.
## What the measurement says
Off-loading does not delete the cost, it relocates it. Three things stay on the loop:
| Component | Measured |
|---|---:|
| Inline verify (today) | **8.92 ms** |
| Dispatch to the worker | 210 ns |
| Drain the continuation off `LoopContext` | 13 ns |
| Loop's own work slowed by shared-L3 eviction | **0.05 – 5.44 ms** |
Net gain **3.5 – 8.9 ms** of on-loop time per login. Harness in `ModernUO-Benchmarks` (`Benchmarks/Argon2OffLoop/`): it models the loop as a dependent-load pointer chase swept across working-set sizes, which is an upper bound on cache-latency sensitivity, and copies `EventLoopContext` so the hand-off cost is the real one.
Two results shaped the design:
- **The contention tax peaks in the middle of the working-set range**, not at the top — 5.44 ms at 8 MiB (a quarter of this chip's L3), but 0.76 ms at 30 MiB and 0.10 ms at 256 KiB. A tiny hot set has nothing in L3 to lose; a huge one is already DRAM-bound.
- **Per-login tax falls as concurrency rises** (5.44 → 2.56 → 1.60 ms at 1/2/4 hashers) while *total* loop damage rises. Contention is shared, not additive, so a login rush is not the disaster case — a single login is.
## Why exactly one worker
It is load-bearing three times over, which is also why it must not quietly become a pool:
- **Cost bound.** Off-loop loses to inline only if a hash steals ~82% of the loop's throughput. One hasher contending for one core leaves the loop ~50%. **A single background hasher cannot cost the loop more than the inline verify under any scheduling regime**, which is what lets the measurement hold on hardware we cannot inspect — AMD, VPS, oversubscribed VM. Four hashers drop the loop to ~20% and break it.
- **Memory.** Exactly one hashing arena is live at a time whatever the login volume.
- **Ordering.** Writes apply in dispatch order *only* because a single thread drains FIFO. A second worker would need ordering reintroduced; `WritesApplyInDispatchOrder` fails if that happens.
Throughput is ~110 verifies/sec. Only loop time matters, not login latency, so head-of-line blocking during a rush costs nothing.
## Making every protection safe off-thread
The worker was initially Argon2-only. That was the right call for the wrong reason — it was blamed on Argon2's salt RNG, which is a stateless syscall wrapper and was never a problem. The real blockers were elsewhere, and both are fixed at the source:
| Protection | Was | Now |
|---|---|---|
| MD5/SHA1/SHA2 | shared `HashAlgorithm.ComputeHash`, which carries the running digest across `HashCore`/`HashFinal` through process-wide singletons | static `HashData` into a `stackalloc` span — no state, no allocation, identical bytes |
| PBKDF2 | `Utility.RandomMinMax` → shared `System.Random`, thread-unsafe *and* game state | `RandomNumberGenerator.GetInt32`, matching the salt beside it |
| Argon2 | already safe (`Verify` is static + stackalloc) | unchanged, singleton reused |
Literal digests are pinned in a test **before** the change and still pass after it. These are compared as strings against every account database, so any casing or encoding drift would lock out every SHA and MD5 account at once.
With all three safe, the worker no longer knows which algorithm it runs and the dispatch conditions collapse to "is off-loop available".
## Correctness
- **Phrase derivation** moves to `AccountSecurity.DerivePhrase`, so verification (stored algorithm's rule) and rehash (target algorithm's rule) cannot disagree. Deriving with the wrong one is the shape of the lockout fixed in #2562.
- **Liveness** is checked at dequeue *and* at apply — a connection can drop while queued or while the result sits in the loop queue. A job with no connection attached, such as an admin password change, runs regardless.
- **Queue overflow rejects** a login rather than verifying inline; steering work back onto the loop is what a flood wants. A password change instead falls back to hashing inline, because unlike a login it must not be dropped.
- **Shutdown and crash** both just stop the thread, and pending jobs are dropped. No save is initiated once shutdown begins — saving is the operator's choice up front, via the admin gump's save/no-save variants, and `WaitForWriteCompletion` honours one already in flight — so a write applied during teardown would reach no disk. The crash path needs its own subscription because `HandleClosed` skips `InvokeShutdown` when crashed.
## Bounding
`MaxPending` is 4096 — a backstop, not a flood defense. `SentFirstPacket` holds a connection to one pending verify and the engine caps connections at 4096, so the queue is already bounded by construction and this can only trip if that invariant breaks. A cap low enough to blunt an attack would reject real players first; during a mass reconnect they *are* the queue. Flood defense belongs at the connection layer.
The real DoS improvement is elsewhere: today every attempt stalls the world, and after this a flood occupies one core while the loop keeps ticking.
## Gate
Release builds on 4+ cores. Below that there is no spare core to move work to, so off-loading buys nothing by construction; `DEBUG` is excluded because dev boxes and test shards have few logins. Both modes call the same code — the gate only chooses where it runs.
## Engine change
One property, `AccountLoginEventArgs.Deferred`, so a subscriber can say "no verdict yet". `EventSink.AccountLogin` is `Action<...>` with no continuation, and the packet handler replies in the same call. Approved separately since it touches `Projects/Server/`.
## Docs
`dev-docs/threading-model.md` and the threading skill gain a vetted-workers section. The forbidden-patterns table bans `new Thread`, `ConcurrentQueue<T>`, `Interlocked` and `volatile` in `UOContent`, and its exceptions covered only `Projects/Server/` — the existing Advanced Search fan-out already sat outside it. The new section leads with proving the need (measure on-loop time, not wall-clock; gate on core count; record the measurement), keeps game logic on the loop via chunking, and documents the hand-off protocol in both directions.
## Testing
698 UOContent tests, 810 Server tests, Release build clean.
Covered: verify and rehash outcomes, phrase rules for SHA1/SHA2 vs Argon2, stored-format stability for MD5/SHA1/SHA2, jobs with no connection attached, and dispatch ordering through the real queue. The liveness and ordering guards are mutation-verified.
## What
`Dictionary<K,V>.Remove` and `HashSet<T>.Remove` do not bump the collection's version, so removing an entry during a `foreach` does not invalidate the enumerator. A number of loops were still paying for a `PooledRefQueue`/`PooledRefList` to collect keys and drain them in a second pass. This drops those guards.
## Why it's safe
Verified against .NET 10.0.10 rather than taken on trust, since the documented guarantee covers only `Dictionary<TKey,TValue>.Remove` while several of these call sites are `HashSet<T>` or enumerate `.Keys`/`.Values`:
| Case | Result |
|---|---|
| `Dictionary` foreach + `Remove` | safe, all entries visited |
| `Dictionary.Keys` / `.Values` foreach + `Remove` | safe, all entries visited |
| `HashSet` foreach + `Remove` | safe, all entries visited |
| `Dictionary` foreach + `Remove` **then `Add`** | throws `InvalidOperationException` |
Reflection on `_version` confirms the mechanism: neither `Dictionary.Remove` nor `HashSet.Remove` touches it. Because `Remove` never bumps the version, the `Keys` and `Values` enumerators are just as safe as the dictionary's own, even though only `Dictionary.Remove` documents the behaviour. No entries were skipped in any case.
The `HashSet` half is confirmed by [stephentoub on dotnet/dotnet-api-docs#8177](https://github.com/dotnet/dotnet-api-docs/issues/8177#issuecomment-1167251052): *"Both HashSet and Dictionary have been improved to support removal during enumeration. The docs may just benefit from updating."* The gap is in the documentation, not the runtime.
`Remove` followed by `Add` in the same enumeration still throws. That is the line this PR does not cross.
## Guards removed
`VisibilityList`, `ChampionTitleSystem`, `Channel`, `BombingRun`, `Ruleset`, `PuzzleChest`, `RaceChangeGump`, `StepCache`, `PlayerMurderSystem`, `VirtueSystem`, `ProjectedItem`, `StaminaSystem`, `AIGroupMovement`, `PromotedGuard`, `AutoDenylist`, `LoginAllowlist`, `AntiMacroSystem`, `DetectHidden`.
Both collection kinds are covered: `Dictionary` (including loops over `.Keys` and `.Values`) and `HashSet` (`ProjectedItem._active`, `PlayerMurderSystem._contextTerms`, `StaminaSystem._resetHash`). In `StaminaSystem.ResetTimer` the `Count == queue.Count → Clear()` branch goes away with the queue — it only existed to avoid paying for N individual removes.
Where the collection supports it, `Contains` + `Remove` and `TryGetValue` + `Remove` also collapse into a single lookup (`if (list.Remove(x))`, `if (m_Pending.Remove(ns, out var state))`).
`Utility.Tidy<K,V>` keeps its two branches: when `K` is serializable the value is not inspected, otherwise the value is. Only the serializable side may be cast, so `Dictionary<Mobile, int>` and `Dictionary<Mobile, string>` stay valid.
## Deliberately unchanged
**`BaseCreature.LoyaltyTimer.OnTick`** keeps its deferred-delete queue. Removing from `World.Mobiles` while enumerating it is safe, but `Mobile.Delete()` is not a `Remove` — it runs `OnDelete`/`OnAfterDelete`, the `OnParentDeleted` cascade over the creature's pack, `DropHolding()`, and region and guild callbacks. Anything in that surface that constructs a `Mobile` is an `Add` into the dictionary being enumerated, which does invalidate it. `BaseHire.PayTimer.OnTick` has the same shape and is likewise untouched.
**Spatial-query buffers** — `GuardedRegion.CallGuards`, `Thunderstorm`, `Exorcism`, `LeverPuzzleController`, `BaseCreature.TeleportPets` — are a different hazard. They buffer the result of a range query because the drain moves or harms mobiles, which mutates sectors mid-enumeration.
**Re-entrant drains.** The `_users` sets in `Firebomb` and the explosion, conflagration and confusion-blast potions look like this pattern but are not: the loop collects, `Clear()`s, and only then runs `Target.Cancel` on each, which can re-enter. `AnimalTrainer` enumerates `pm.Stabled` and drains through `RemoveStabled`, which nulls the `Stabled` field once it empties — safe for an in-flight enumerator, which holds the set reference rather than the field, but subtle enough not to be worth inlining on a cold path.
## Verification
`dotnet build` clean with 0 warnings; 810 Server and 684 UOContent tests pass.
## The bug
Any property getter reached from `GetProperties` that calls `InvalidateProperties` takes the tooltip build down with it:
```
System.ArgumentNullException: Value cannot be null. (Parameter 'array')
at Server.ObjectPropertyList.AppendStringDirect(String value)
at Server.Mobiles.PlayerMobile.GetProperties(IPropertyList list)
```
`InvalidateProperties` rebuilds **in place** — `Reset()`, then `GetProperties()` again on the same instance — and `Reset()` does two destructive things to a build already in flight:
1. **It returns the pooled interpolation buffer.** The compiler rents it in the handler ctor and returns it in the closing `Add`, so *every hole is evaluated while it is live*:
```csharp
var handler = new InterpolatedStringHandler(1, 2, list); // InitializeInterpolation() RENTS
handler.AppendFormatted(pl.Rank.Title); // <-- getter runs HERE
handler.AppendLiteral("\t");
handler.AppendFormatted(faction.Definition.PropName);
list.Add(1060776, ref handler); // consumes span, RETURNS
```
```
GetProperties(list)
├─ InitializeInterpolation() -> _arrayToReturnToPool = Rent(256) buffer LIVE
├─ « hole 1: pl.Rank.Title »
│ └─ PlayerState.Rank.get (lazy recompute)
│ └─ Invalidate() -> InvalidateProperties() -> m_PropertyList.Reset()
│ └─ Dispose(): Return(buf); _arrayToReturnToPool = null buffer GONE
└─ handler.AppendFormatted("Knight")
└─ _arrayToReturnToPool.AsSpan(_pos..)
└─ ArgumentNullException (Parameter 'array')
```
It surfaces as `ArgumentNullException` rather than `NullReferenceException` because the `Range` overload of `AsSpan` must read `array.Length`, so the BCL null-checks and names the parameter `array`.
2. **It rewinds the packet cursor**, so properties already written are overwritten by the nested pass — a silently corrupted tooltip even where the buffer survives.
## The fix: refuse, don't recover
There is no correct recovery, and retrying the build would only hide the defect. A nested invalidation now logs an error with a stack trace, **throws in `DEBUG`** so it gets found and fixed, and in `RELEASE` returns without touching the list — a possibly stale tooltip, but no crash, no corrupted packet, and nothing leaked back to the pool. Getters that genuinely must invalidate should defer:
```csharp
Timer.DelayCall(InvalidateProperties);
```
The guard flag lives on the `ObjectPropertyList`, not the entity: it is that list's own lifecycle, it costs nothing (both `Item` and `ObjectPropertyList` absorb it in existing padding, and the list is allocated lazily), and it stays correct when builds for different entities nest.
Base instance sizes are unchanged from `main`: Item 128 B, Mobile 792 B, ObjectPropertyList 72 B, PlayerMobile 1216 B.
`PropertyList` also publishes the list into `m_PropertyList` **before** building it rather than assigning through `??=` afterwards, so a nested `InvalidateProperties` sees the build in progress instead of recursing into a second throwaway list whose work is discarded.
`ObjectPropertyList` re-rents its scratch buffer instead of spanning a null array, so a stray `Reset()` from any other caller degrades rather than aborting `GetProperties`.
## Factions `PlayerState`: maintained, not lazily computed
The getter that surfaced this is now a plain field read — the whole `if (m_InvalidateRank)` block and the flag itself are gone:
```csharp
public RankDefinition Rank => m_Rank;
```
`UpdateRank()` recomputes at each point an input actually changes:
| Site | Why |
|---|---|
| `RankIndex` setter | this player's index changed |
| end of `KillPoints` setter | two paths write `m_RankIndex` directly, bypassing the setter; runs once the swap bookkeeping and `ZeroRankOffset` have settled |
| `Faction.AddMember` | *after* the insert — the member count is not settled during the ctor |
| `FactionState` load | once ordering and `ZeroRankOffset` are final |
Supporting fixes this forced out:
- **Both ctors seed the lowest rank.** Nothing recomputes on read any more, so `Rank` has to be usable immediately — including for members that never get a `RankIndex` assigned, which is *every member with no kill points*. Without this, `Rank.Title` NREs.
- **`Rank` always resolves.** Ranks are ordered by `Required` descending ending at `0`, so a *negative* percent (`RankIndex` out of sync with `ZeroRankOffset`) matched nothing and left `m_Rank` null. It no longer divides by a zero `ZeroRankOffset` either.
- **A pre-existing staleness bug.** The `KillPoints` setter writes `m_RankIndex` directly in two places, so the cached rank was never refreshed when a player crossed zero kill points.
All six readers of `Rank` were checked; none relied on the old side effect.
One behaviour change worth flagging: rank refreshes are now **eager** where they used to be lazy, so a `KillPoints` change invalidates each swapped player as it happens. The swap loops break as soon as ordering is satisfied — typically 0–2 swaps — but it is on the path that runs on every faction kill.
## Documentation
The rule is written down so it is enforceable rather than folklore:
- **CLAUDE.md** audit rule 19
- **`dev-docs/property-lists.md`** — new "Never Invalidate From Inside `GetProperties`" section with the failing/passing pattern
- **`dev-docs/claude-skills/modernuo-property-lists.md`** — key rule + anti-pattern
- **`dev-docs/claude-skills/modernuo-code-audit.md`** — rule 19, ERROR severity
## Tests
- `ObjectPropertyListReentrancyTests` — `Reset()` and `Dispose()` re-entered mid-hole (both red against `main` with the exact exception above), nesting behaviour, and the new contract: `DEBUG` throws, `RELEASE` survives, and the build is never retried into a loop.
- `FactionRankTests` — `Rank` is populated before anything reads it, tracks `RankIndex` without a read, is stable across reads, and still resolves when `RankIndex` is out of sync with `ZeroRankOffset`. Red-verified: removing the ctor seed fails the first one.
793/793 `Server.Tests` and 608/608 `UOContent.Tests` pass.
## Noted, not addressed here
`~ObjectPropertyList()` returns the rented array to `STArrayPool<char>.Shared` from the **finalizer thread**, and that pool is single-threaded by design. Left alone as a separate concern.
### Summary
Moves inventory insurance out of `Mobile`/`PlayerMobile` into its own system at `Projects/UOContent/Engines/Insurance/`, wires it into the feature flag system, and makes disabling it actually disable it everywhere.
### Changes
**New `Server.Engines.Insurance.Insurance` system**
* Owns its own `Configure()`, seeding from the existing `insurance.enable` setting (default `Core.AOS`), so no config migration is needed. `Mobile.InsuranceEnabled` is gone, along with its line in `ExpansionConfiguration`.
* `CanInsure`, `GetInsuranceCost`, `ToggleItemInsurance`, `AutoRenewInventoryInsurance`, `CancelRenewInventoryInsurance` and `OpenItemInsuranceMenu` move here from `PlayerMobile`, which keeps four one-line shims for the context-menu callbacks.
* Every entry point is gated on `Insurance.Enabled`, and the death-time state is only allocated when insurance is on — a shard without insurance pays nothing for it.
**Feature flag integration**
Insurance is now a first-class feature flag: `ServerFeatureFlags.InsuranceEnabled`, registered under the `insurance` key in `FeatureFlagManager.SyncStaticFlag`, so it can be inspected and toggled through the normal flag command/gump rather than only at boot. `Insurance.Enabled` reads through to the flag, so there is one source of truth for every consumer.
**Fixes a memory leak from PvP**
`PlayerMobile.m_InsuranceAward` was a `Mobile` field assigned on every death and never cleared, so every player permanently pinned a strong reference to the last player who killed them. Killers were kept alive by their victims indefinitely.
Death-time insurance state now lives in a `Dictionary<Mobile, InsuranceContext>` owned by the insurance system: the entry is created in `OnBeforeDeath` and removed in `OnDeath`, so nothing outlives the death that created it.
**Removes insurance fields from every PlayerMobile**
`m_InsuranceAward`, `m_InsuranceBonus` and `m_NonAutoreinsuredItems` were carried by every `PlayerMobile` whether or not the shard ran insurance. All three are gone; the equivalent state is allocated per-death, only for players who actually die with insured items, only when insurance is enabled.
**Stale `Insured` flags are inert when insurance is off**
`Item.Insured` is a persisted flag, so items stay marked after a shard turns insurance off. Every read path now checks the flag first, so those items behave exactly as if they were never insured:
* `Item.CheckBlessed` / `Item.IsStandardLoot` — they drop again instead of acting blessed
* `Item.AddLootTypeProperty` — no more phantom "insured" tooltip
* `PlayerMobile.FindItems_Callback` — not yanked out of nested bags on death
* `DestroyEquipment` — no longer immune
* `ClothingBlessDeed` — no longer reports "that item is already blessed"
**Gumps promoted out of `PlayerMobile`**
`ItemInsuranceMenuGump`, `ItemInsuranceMenuConfirmGump` and `CancelRenewInventoryInsuranceGump` were private nested classes reaching into `PlayerMobile` privates. They are now public types in `Engines/Insurance/Gumps/`, talking to the insurance system through its public API. `ItemInsuranceMenuGump.ToggleSelected()` replaces the confirm gump's reach-in to the parent's `_items`/`_insure` arrays.
### Behavior changes
* The per-item "You lack the funds to purchase the insurance" message on failed auto-renewal is no longer sent during death; players get the single 1061115 summary instead. Marked with a TODO pending a decision on whether the per-item message should spam.
* The killer's insurance bonus is deposited once at the end of death processing rather than 300 gold at a time per insured item, and the "gold has been deposited" message is now conditional on the deposit succeeding. Same total.
### Drive-by cleanups
`PoisonImpl.IncreaseLevel` -> `Poison.IncreaseLevel`, a redundant `is NetState { } ns` pattern, `new List<Item>(Items)` -> collection expression, alignment of the `SyncStaticFlag` switch arms, and some comment/formatting fixes in `PlayerMobile`.
## Summary
`AdvancedSearchThreadWorker.Execute` signals `_stopEvent` **before** clearing `_pause` and **before** reading the exit condition. `Sleep()` unblocks the instant that signal fires, so the owning thread can begin the next cycle while the worker is still finishing the previous one — and the worker's two trailing operations then land on the new cycle's state.
`SerializationThreadWorker` already orders the same handshake correctly and documents why (`Projects/Server/Serialization/SerializationThreadWorker.cs`):
```csharp
// The owning thread may start another pause cycle the moment _stopEvent is set
// (Exit does exactly that). Clear _pause and sample the exit condition before
// signaling, or the new cycle's pause request is clobbered / its Sleep orphaned.
var exiting = Core.Closing || worker._exit;
Volatile.Write(ref worker._pause, false);
worker._stopEvent.Set();
```
This applies the same ordering to the search worker. Three lines; no behavior change on the happy path.
## The two failures
**Reuse hang.** The next cycle's `Wake`/`Push`/`Sleep` writes `_pause = true`, then the worker's stale `_pause = false` lands on top of it. The inner loop never observes `pauseRequested`, its queue is already empty, and it spins on `Thread.Yield()` forever — so the owning thread's next `Sleep()` waits on a `_stopEvent` that is never set again. A single search wakes each worker exactly once, so this only surfaces once `_threadWorkers` is reused by a later search.
**Orphaned `Exit()`.** `Exit()` sets `_exit`, `Wake()`s, then `Sleep()`s — the moment the drain's `Sleep()` returns. Reading `_exit` *after* the signal, the worker can observe that fresh `_exit`, return without ever consuming the `Wake`, and leave `Exit()`'s `Sleep()` waiting on a signal nobody will send. The `_thread.IsAlive` guard doesn't close this: the thread passes the check and returns immediately after.
## Verification
Verified with two throwaway timing tests — 25k reuse cycles and 2k drain-then-`Exit` cycles, each under a bounded wait:
| ordering | result |
|---|---|
| previous | `Failed: 2, Passed: 3` — both reproduce, cleanly at the 20s bound |
| this PR | 3 consecutive runs, 5/5, ~0.6s |
**Those tests are deliberately not included.** Their reproduction threshold is a property of one machine's scheduler — at 2k and 200 cycles the buggy build passed — so as permanent tests they'd cost ~560ms and 2000 thread creations on every suite run for a guarantee that may not hold on a CI runner. The ordering is protected the same way `SerializationThreadWorker`'s is: by the comment at the call site.
`UOContent.Tests`: **597/597**.
## Problem
Every map's `.swb` step cache was opened, indexed and logged **twice** on boot.
`MovementPath.Configure()` explicitly called `PathCacheCommands.Configure()` and `CacheEvictionTimer.Configure()`. Both are types exposing a public static parameterless `Configure()`, which `AssemblyHandler.Invoke("Configure")` already discovers and calls once each (`AssemblyHandler.cs:157`). So `PathCacheCommands.Configure()` ran twice, and `AutoLoadAtStartup()` with it. `PathCacheCommands.Configure()` called `PathfindRecorder.Configure()` the same way.
`TryOpenLazyReader` disposes the prior reader before replacing it, so there was no handle leak — but the header and full chunk index of each `.swb` were read twice (~48 MB of files across six facets). The expensive `.mul` hashing was already memoized, so it was not doubled.
## Fix
Consolidate the cache lifecycle into `Initialize`:
- `Configure()` keeps only settings and command registration.
- `Initialize()` opens the readers once, then prebakes only maps that still lack one.
- The post-bake reopen is per-map instead of a blanket `AutoLoadAtStartup()` — on a partial bake (some valid `.swb`, one stale) that would close and reopen the readers already open, a second double-open on a different path.
`Initialize` is the correct phase. `Configure` runs before `TileMatrixLoader.LoadTileMatrix()` and `World.Load()` (`Main.cs:458/460/463/465`), so opening a `.swb` there forced the lazy `Map.Tiles` property — the fingerprint hashes the map files — and built every `TileMatrix` ahead of the loader that owns it, possibly before `TileMatrix.Configure()` settled `Pre6000ClientSupport`. Both sit at the default call priority and the phase sort is unstable. Moving pathfinding out leaves nothing in `Configure` that touches `Map.Tiles`, closing that hazard; the other 22 `.Tiles` users in UOContent are all runtime paths.
Multis stay out of the bake by design — houses and boats are player data that moves, handled by the multi-aware path at query time.
## Logging
The per-map `StepCache: opened ... chunks indexed` line drops to `Debug`. Opening is the expected case; `BakeMap` already logs a rebuild at `Information`, and `Initialize` still emits `PathBake: pre-bake complete (N map(s) written)`.
## Verification
- `dotnet build Projects/UOContent` — 0 errors, 0 warnings.
- `dotnet test --filter FullyQualifiedName~Pathfinding` — **123 passed, 0 failed**.
Boot logs should now show one `opened` line per map at `Debug`, none at `Information`.
## Summary
Hardens the **Advanced Search** engine (`Projects/UOContent/Engines/Advanced Search/`) — the GM entity finder that fans searches across background worker threads. A code review surfaced 14 defects (A–N), including a shard-crasher reachable from a single admin typo and a path that silently disables autosave for the rest of the shard's uptime. Each behavioral fix ships with a test.
Full `UOContent.Tests` suite: **530/530 green** (21 new AdvancedSearch tests).
## Fixes
### Crash / data-loss
- **A — Shard crash on a malformed Property Test.** `AdvancedSearchThreadWorker.Execute` had no `try/catch` and the worker `Thread` is foreground, so a parse throw (`Hits>abc`, `Layer=onehanded` — `Enum.Parse` was case-sensitive, `Hits>1@` — empty sub-expression indexing) terminated the process. Now: `ParseValue`/`CompareValues` use `TryParse`/`Enum.TryParse(ignoreCase)` and return no-match instead of throwing; the per-entity filter is wrapped in `try/catch` (logs + skips); empty expressions are guarded.
- **C — Overlapping searches corrupt state + brick autosave.** `_threadWorkers`/`_threadId` were `static` but `DoSearch` is an instance method; a second search (double-click / two admins) stomped shared worker state and could leave a drain waiting forever on the shared `AutoResetEvent`, so `AutoSave.SavesEnabled` was never restored. Now: an `Interlocked` re-entrancy guard rejects concurrent searches.
- **G — Autosave restore not guaranteed.** The restore lived only in the success callback. Now it's in a `finally` (plus an outer `catch` covering the synchronous setup and a `catch` on the drain body), so autosave + the guard are always released.
### Wrong results
- **D — `@`/`|` operator precedence.** `a@b|c` evaluated as `a && (b || c)` instead of `(a && b) || c`. OR now binds looser than AND (`AdvancedSearchUtilities.EvaluateBoolean`, unit-tested).
- **E — Descending sort, partial last page rendered blank** (the index decreased in descending mode and the `break` early-out killed the loop). Now a bounded `VisibleCount`-driven loop renders the last page in both directions.
- **F — Deleted entities** were not skipped (ghost rows). Now `DoEntitySearch` skips `entity.Deleted`.
- **N — Reference-type comparisons** threw (`Comparer<T>.Default.Compare` on non-`IComparable`) and compared references to a string. Now equality is by value and ordering is guarded to `IComparable` (no throw).
### Worker perf / hardening
- **H** busy-spin → `Thread.Yield()` in the drain; **I** `GetProperties()` cached per `Type`; **J** `HandleValidInternal` moved behind the cheap map/range/region filters; **K** worker threads are `IsBackground` + `Exit()` tolerates an already-terminated worker; **L** `_filter == null` guard; **M** consistent `Volatile` access on `_pause`/`_exit`.
### Documented
- **B** — the residual worker/event-loop read race is documented on `AdvancedSearchThreadWorker`: workers read live entity state concurrently with the loop, so value-type reads may be stale-but-safe and getter exceptions are swallowed; fully eliminating it would require snapshotting entity fields on the main thread (deferred).
## Notes
- New test-only seams (`TryBeginSearch`/`EndSearch`/`IsSearchInProgress`/`VisibleCount`/`TryParseValue`/`EvaluateBoolean`) are `internal` via the existing `InternalsVisibleTo("UOContent.Tests")`.
- Dead `public ParseValue<T>` removed.
- `ConcurrentDictionary` for the reflection cache is intentional — these workers are genuinely parallel.
Reduces the world-save freeze window from ~740ms to ~78ms (measured on a synthetic 10M-entity / 1.7GB world, 24 cores, through the real pipeline classes) by removing the per-entity handoff between the game loop and the serialization workers, fixing how large indivisible payloads are scheduled, rewriting the BufferWriter hot path, removing per-entity placement state entirely, and finally replacing the global serialized-types tracking with a per-file type table (idx v4) that also shrinks idx files by ~21% and speeds the background write phase. The pipeline has also been validated end-to-end on live-copy worlds in the multi-million-entity range, where the freeze is drain-bound (real `Serialize()` costs far more CPU per byte than synthetic writes) — the same structural wins hold, and entity/file round-trips are byte-clean across both load paths.
## The problem
The freeze window is `max(main-thread handoff, slowest worker drain)`:
1. **The producer was the bottleneck.** The main thread round-robined every entity through per-worker `ConcurrentQueue`s — two interlocked ops per entity, ~740ms of freeze floor at 10M entities before any serialization happened.
2. **Round-robin distributes count, not cost.** "Deep" systems (50MB generic persistence blobs) and "thick" entities (100K-item storage keys) landed on arbitrary workers, producing lopsided drain times on large worlds.
3. **Worst-case scheduling.** `GenericEntityPersistence.Serialize` pushed its self-payload *after* all entities, and generic persistences sort last in the registry — so the biggest indivisible blobs started serializing at the very end, extending the freeze by their entire duration.
## The fix
**Commit 1 — chunked handoff + LPT scheduling + heap pre-sizing:**
- Pooled 4096-entity chunks published to one shared queue; workers pull chunks and load-balance dynamically (a worker busy with a thick entity simply takes fewer chunks).
- `Persistence.SerializeAll` pushes systems largest-first (LPT) using the previous save's payload size (or loaded file size on first boot); self-payloads get dedicated single-entity chunks so they overlap the entity stream instead of ending it.
- Worker heaps pre-size from the loaded save's `.bin` totals, eliminating copy-on-grow inside the first save's freeze.
- `SpinWait` backoff in the drain loop (never `Sleep(1)`), per-worker balance stats logged in debug builds (the call site is compiled out of Release), 1MB snapshot write buffer.
**Commit 2 — workers iterate the dictionaries directly + main thread joins the drain:**
- `GenericEntityPersistence` publishes 4096-slot ranges over its dictionary's backing entries array; workers serialize occupied slots (`value != null`) directly through a `ShadowEntry<TValue>` struct mirroring the runtime's private `Entry` layout. Safe because the dictionary is frozen during `Saving` (mutations divert to the pending safety queues).
- The layout is **proven at startup before any code reads through it**: validation measures the true `Entry` stride via precise allocation accounting (guaranteeing all shadow reads are in-bounds), then verifies every key/value of a churned, resized, freelist-exercised dictionary — reading value slots as raw pointer bits only, never materializing a managed reference until the layout is proven. If a future runtime changes `Dictionary` internals, validation fails with a logged warning and saves fall back to the (fully maintained) enumerate-and-push path.
- The main thread joins the drain via an inline worker after publishing, instead of idling — worth a full worker share, proportionally more on low-core hosts.
**Commit 3 — 2.2x faster BufferWriter write path, single-pass short strings:**
- PGO already devirtualizes and inlines every `IGenericWriter.Write` callsite (interface vs concrete measured identical) — the real per-write cost was the non-inlinable `Index` setter (range-check throw path + per-write high-water tracking) plus span bounds checks. Writes now reserve capacity once, then do an unaligned store through a ref with a raw index increment; the high-water mark folds at Seek/Resize instead of per write.
- Class-level implementations of the hottest default interface methods keep nested writes inlined (a DIM re-dispatches on `this` even at a devirtualized callsite).
- Strings of 85 chars or fewer encode once into a stack scratch instead of walking the string twice (`GetByteCount` + `GetBytes`). Byte output is identical.
- Measured: 34.4 → 15.7 ns/entity on a generated-style write mix; end-to-end freeze ~99ms → ~74-82ms.
**Commit 4 — branch-free fallback push loop:**
- A bare `foreach { PushToCache(entity); }` runs at 2.3ns/entity; the same loop carrying a per-entity heavy-check runs 2.3x slower — the cost is the fatter loop body defeating tight-loop codegen. Entity-level >1MB payloads are rare enough to ride in shared chunks; system self-payloads (the large ones) are still explicitly scheduled largest-first.
**Commit 5 — drop the 9-byte per-entity placement state; snapshots write from worker segment logs:**
- Every `ISerializable` carried `SerializedThread/SerializedPosition/SerializedLength` so `WriteSnapshot` could gather each entity's bytes from the worker heaps in dictionary order. But the idx records absolute positions — bin order is free — so the snapshot is now written in worker-heap order and the join inverts: workers log segments (owner, slot range, heap start) plus one length per record as they serialize; positions are implicit because a worker's writes are contiguous, and identity comes from re-walking the same snapshot slots in the same order (stable until `PostWorldSave`).
- Chunks are persistence-homogeneous (the partial chunk publishes at each `SerializeAll` boundary) so segments route to files by owner with zero per-entity state. Self-payloads keep placement as three private fields on the handful of persistence instances.
- Net: 9 bytes (plus padding) of resident state removed from every item, mobile, guild, and account on every shard; three interface-property stores per entity leave the drain hot path (stamping dirtied one cache line per entity mid-freeze — the lengths log is one sequential stream); each segment's bytes hit the bin as a single span write instead of one copy per entity, speeding the background write phase; and `IGenericSerializable` shrinks to just `Serialize(IGenericWriter)`. Transient cost: ~4 bytes per entity in pooled per-worker logs, released after each write. The save format was unchanged at this point (idx v3, same loader); the v4 bump comes later in the branch.
**Commit 6 — staged file writes replace memory-mapped snapshot writing:**
- `MemoryMapFileWriter` is removed. `FileBufferWriter` composes through the full `BufferWriter` raw write path into a pooled staging block that drains to the file as large sequential positional writes (`RandomAccess.Write`); seeks flush the block and move the file offset, so backwards patches (the idx entity count) become small positional writes.
- Memory-mapped composition paid a soft page fault on every composed page plus unpredictable dirty-section teardown stalls at dispose — measured ~4x slower end-to-end than staged writes at snapshot sizes.
**Commits 7–11 — idx v4: per-file type table replaces SerializedTypes.db and all runtime type tracking:**
- Previously every `Write(Type)` from every worker enqueued into a shared `ConcurrentQueue<Type>` during the freeze (interlocked writes on a shared cache line, millions of mostly-duplicate entries), the background phase drained and deduped it all into a `HashSet`, and the snapshot recomputed `xxHash64(Type.FullName)` once per entity record (~5.4M redundant hashes per save on a large world) to write 9-byte tag+hash idx records plus a global `SerializedTypes.db`.
- The db's only real job was diagnostics: the string name behind "Type `<X>` was not found. Delete all of those types?" during idx loading. That map now lives in the idx itself: each `GenericEntityPersistence<T>` keeps an insertion-ordered `Type -> ushort` table, hydrated at `AddEntity` and on every deserialize path — one dictionary `TryAdd` per entity add on the game thread, amortized across gameplay, and provably immutable while the background writer reads it (adds divert to the pending queues during saves).
- idx v4 layout: the table (names only) is written before the records; records reference it by 2-byte index, shrinking from 33 to 26 bytes (−21%). The loader resolves each table name **once** (`FindTypeByHash(ComputeHash64(name))` — semantically identical to v3 resolution, `TypeAlias` included) into a constructor array, and each record becomes an array index instead of an 8-byte hash read plus dictionary probe. The unresolved-type prompt now surfaces once per type, with the name.
- Deleted outright: `World.SerializedTypes`, the drain/dedupe pass in `WriteFiles`, `BufferWriter`'s type tracking (its `Write(Type)` is now pure — payload format unchanged: tag byte + xxHash64), `FileBufferWriter`'s typeSet parameter, `Persistence.WriteSerializedTypesSnapshot`, and the adhoc db write. SerializedTypes.db is no longer produced.
- **Backward compatibility:** v0–v3 saves (including their SerializedTypes.db and legacy tdb files) load exactly as before, and every legacy load path hydrates the new table so the first v4 save after an upgrade is complete. Stale db files in existing save folders are simply ignored. Verified live: a v3 save boots, saves as v4 (Items.idx −20.2% on a dev world), and reloads with identical entity counts.
## Measured (synthetic 10M entities / 1.7GB, 64+64+32MB system blobs, 24x 2MB thick entities, dense write profile, 24 cores)
| Metric | Before | After |
|---|---|---|
| Steady-state freeze | ~740 ms | **~78 ms** |
| Main-thread publish cost | ~740 ms | **~0.1 ms** |
| Steady-state allocations | 0 | 0 (by iter 2) |
| Worker byte-load spread | 2x | ~1.15x |
The freeze is now bound by pure serialize throughput (payload / cores).
## Tests
- 779 Server.Tests + 501 UOContent.Tests pass.
- New across the branch: chunk fill/flush/owner-boundary tests, pool reuse/clear tests, an end-to-end multi-worker drain through the real wake/push/flush/pause protocol, a 50K-entry churn equivalence test for the shadow iteration re-walk (the exact pairing the snapshot writer relies on), byte-level BufferWriter output/position pins, `RuntimeLayoutIsSupported` so a silent fallback on a future runtime upgrade fails loudly in CI, and a full snapshot **round-trip test** that serializes 25K entities plus a self-payload through real workers, writes the idx/bin from the segment logs, and reloads them through the standard loader (now in v4 format).
- For idx v4 specifically: `FileBufferWriter` staging/drain/seek-patch and oversized-item tests, type-table registration tests, a hand-written v4 fixture proving an unresolvable type name skips only its own records through the console confirmation flow, and a hand-written **legacy v3 fixture** proving old saves still load and hydrate the type table for their next save.
## Trade-offs
- Chunk scheduling is nondeterministic, so worker heaps ratchet to each worker's max-ever draw rather than a fixed share. With slot ranges the balance is tight (~1.15x), so the effect is small; a shared slab pool remains an option if production shows retention creep.
- Entity-level heavy items inside slot ranges are serialized wherever they're encountered (no LPT for them); worst-case tail is one thick entity's serialize time (~ms). System self-payloads — the large ones — are still explicitly scheduled largest-first.
- Snapshot-write error granularity is per segment rather than per entity (heap-bounds bugs were the only thing the per-entity catch ever caught; idx metadata reads keep per-record granularity).
- idx v4 is a save-format version bump: old saves load unchanged through the preserved legacy paths, but saves written by this branch require this loader. Per-persistence type tables cap at 65,535 distinct entity types per boot (hard throw, orders of magnitude of headroom), and a type's table slot persists until restart even if its last entity is deleted — a few stale name entries per file, by design.
Started as an allocation pass over `StepCache` and grew into a cleanup of the surrounding pathing engine. Four commits, each independently reviewable; net **−560 lines**.
Build clean (0 warnings). All 122 `Server.Tests.Pathfinding` tests pass.
---
## 1. `perf`: pool the strata buffer, cut a hot-path dictionary lookup
**The headline is that `TryGetMask` — the actual hot path — was already allocation-free.** `StepMask` is a readonly struct, `StaticTileEnumerable` is a `ref struct`, `ChunkMissState` is a struct in a `Dictionary`. So most of this is a bake-throughput and GC-churn win, with one exception noted below.
`BuildChunk` accumulated packed multi-Z strata into a `List<byte>` that grew by doubling (256 → 512 → 1024 → …) and then paid a final `ToArray()`. A full map bake runs it ~114k times. It now writes into a `byte[]` rented from `STArrayPool<byte>.Shared` through a span writer, and hands the chunk one exact-size copy.
**This required fixing a latent out-of-bounds guard.** The record-fit check reserved headroom for **8** strata (`StratumByteLength * 8`) while `ComputeStandableSurfaceZs` can return up to **16** — so a cell could write 305 bytes starting from a 65,383-byte offset. Against a `List` that was benign (it just grew past 64 KB, and emitted offsets stayed under the `NoStrata` sentinel). Against a fixed-size rented buffer it is an out-of-bounds write, so tightening it was a *prerequisite* for the pooling, not a drive-by. The guard is now exact, which additionally proves no emitted offset can collide with `NoStrata == ushort.MaxValue`.
**One genuine query-path win:** `ShouldPromoteAfterMiss` did *two* dictionary lookups per miss — a `TryGetValue`, then an indexer assignment that re-hashes and re-probes. It now mutates in place via `CollectionsMarshal.GetValueRefOrNullRef`. This runs on every uncached chunk touch during A* expansion. The window-expiry branch keeps its explicit early return, so `MissPromotionThreshold == 1` still resets rather than promoting.
Also dropped `StepProbe.ComputeStrataAt` / `ComputedStratum` (dead code, zero callers) and collapsed six 18-argument `new StepMask(0, 0, …, kind)` blocks into `Fallthrough(kind)`.
**Considered and rejected:** pooling the `Direction[]` that `Find` returns. It *escapes* the call — `MovementPath` holds it across ticks while `PathFollower` walks `m_Index` through it — so it cannot be rented-and-returned, and it cannot be borrowed from the shared `BitmapAStarAlgorithm.Instance` without one creature clobbering another's in-flight path. `CheckPath` rate-limits repaths to one per 2s per creature, putting this at roughly 60 KB/sec at 1,000 pathing creatures. Not worth a public API break plus a use-after-return footgun.
## 2. `docs`: rewrite the comments for publication
The comments had accumulated as development notes: internal phase jargon (`Tier 4`, `the Phase-2 synthesizer`), change narration aimed at a reviewer (`which the old ComputeStandingZ anchor missed`, `legacy behavior`), benchmark anecdotes (`benchmarked as near-optimal`, `a ~20 ns lookup`), and paragraphs restating the code.
Rewritten to keep the rationale you cannot recover by reading the code — why the source-Z guard cannot be widened, why multis fall through with a halo, why the promotion gate counts Finds rather than calls, why `ComputeFingerprint` must hash the *files* and not the live tile tables — and drop the history that got us there.
Three comments were **factually wrong**, not just wordy:
- `CacheEvictionTimer` and `CacheStats` documented a class called `StaticWalkabilityCache`. No such class exists — it is `StepCache`.
- `StepCacheFile` declared `File layout v8` while `FormatVersion` is 9, and called the current record layout "the v6 layout" in four places. The layout descriptions are now unversioned so they cannot drift again.
- `StepProbe.ComputeStandingZ` claimed `StepCache` uses it to bake `SourceZ`. It has not since the baker moved to the clearance-aware `ComputeStandableSurfaceZs`; only a parity test calls it.
## 3. `refactor`: simplify `StepCacheFile.Write`, consolidate the format tests
`SaveToFile` walked `_keysList` **twice** — once to count the map's chunks, then again through a `ChunkEnumerator` closure to emit them — because `Write` needed the count up front to size its index array. Both loops had the same root cause. Passing a **span** collapses them: the count is just `span.Length`.
That deletes the `ChunkEnumerator` delegate, the closure over the list enumerator, and **both `InvalidOperationException` throws**, which existed only to police the delegate's "yield exactly `chunkCount` chunks" contract — a contract a span makes unrepresentable.
`Write` now patches the header's `IndexOffset` by seeking back to it rather than reaching into the writer's live buffer with `BinaryPrimitives`. That also retires `IndexOffsetFieldPosition`, a hand-maintained byte offset that had to track the header layout, and sidesteps the stale-array hazard that motivated the manual patch (`BufferWriter` reallocates on growth).
**Tests:** `StepCacheFileV6/V7/V8Tests` were named for the format version that introduced each transform — and the format is now **v9**, so all three names described formats the loader rejects outright. Beyond triplicated builders and plumbing, two things were actually broken:
- The three near-identical rejection tests each cited a `MinSupportedVersion` that had since moved (`"version 5 < MinSupportedVersion 6"`, `"6 < 7"`, `"7 < 8"`). They passed for the wrong reason.
- `AssertBaseEqual` (used by V7 and V8) **silently skipped the swim and strata trailers**. A regression dropping either would not have failed those tests.
Now one `StepCacheFileFormatTests`, named for behavior — predictive-Z elision, compression, compact index — with a single `AssertIdentical` that does check both trailers, the three rejection tests folded into one theory that also covers a future version, and a zero-chunk case the delegate-based writer never had coverage for.
## 4. `test`: consolidate the parity and lifecycle tests
Three files tested "parity" and none of the names said *which*. They were three different layers, and the seams are the useful part, so they are now one `StepCacheParityTests` that names them:
| Test | Compares | Answers |
|---|---|---|
| `ProbeMatchesSlowPath` | StepProbe vs MovementImpl | Is the bake right? |
| `CacheMatchesProbe` | StepCache vs StepProbe | Is it stored and returned intact? |
| `CacheServesReachableWalkStates` | StepCache vs MovementImpl | End to end, over the states A* visits |
Merging removed a duplicated stub `Mobile`, duplicated region seeds, and a filename/class mismatch (`StepProbeParityTests.cs` declared `StaticWalkabilityParityTests`). `SwimBake_ProducesWetCells` moved with it — it lived in the cache parity file but never touched the cache.
Tests reached into `StepCache._chunks` via `GetField` in **9 places**, each rebuilding the key encoding and cell-index arithmetic by hand. `StepCache` now exposes `GetResidentChunk` and `ResidentIndexInSync` alongside the internal test hooks it already had (`LazyReaderHasChunk`, `CurrentFindGeneration`), and the shared arithmetic moved to `PathingTestSupport`. All 9 reflection blocks are gone.
`StepCacheLifecycleTests` is regrouped by what it covers — promotion gate, fallthrough routes, strata, swim layer, eviction — with the `Tier4*` names dropped. Removed `Singleton_IsAvailable`, which asserted an inline-initialized static property was not null; that is the entire 123 → 122 test-count delta.
---
## Verification
Tests were mutation-checked rather than just run, since round-trip and parity tests can pass while a transform silently no-ops:
- Injecting an off-by-one into the `IndexOffset` patch fails **15 of 123** — the format tests are load-bearing.
- Offsetting the cache's cell index by one fails **7 of 10** parity cases, and the 3 that stay green are exactly the ones that do not touch the cache. The layering localizes a fault rather than just reporting one.
Phase 2 follow-up to #2510 — wires acquisition for the gargoyle Throwing content that Phase 1 deliberately left out.
## Changes
- **SA loot flavor (`IsStygian`)** — completes the dead loot path from the original PR: adds `SAWeaponTypes`/`SARangedWeaponTypes` pools + `isStygian` branches to `Loot.RandomWeapon`/`RandomRangedWeapon`, **and** the missing piece — computes `IsStygian` (`map == Map.TerMur`) in `LootPackEntry.Construct` and threads it through `LootPackItem.Construct`. Ter Mur creatures now roll SA gear + the three throwing weapons (Boomerang/Cyclone/SoulGlaive) from their normal `BaseWeapon`/`BaseRanged` loot entries. Conservative `TerMur`-only (not ServUO's extra `|| RandomBool()`).
- **Valkyrie's Glaive** — re-added as a self-contained Ter Mur stealable artifact at `(843, 665, 27)`, matching ServUO/OSI, with the previously-missing `ArtifactRarity => 5`.
## Deferred (documented)
The 5 host-dependent artifacts (Raptor Claw, Stone Slith Claw, Storm Caller, Banshee's Call, Wind of Corruption) are intentionally NOT included — their OSI drop sources (Raptor, StoneSlith, and the renowned/boss creatures + a `BaseRenowned` artifact-list system) don't exist in ModernUO yet, so re-adding the items now would leave them `[add`-only. They'll follow a dedicated SA-creatures effort.
## Notes
- No new tests: both changes are property/plumbing with RNG-driven output — no deterministic complex logic to assert (consistent with the repo's test-scope conventions).
- Verified: server + test project compile; throwing suite 14/14.
Supersedes #2376 (@jwvalentine). This is a reviewed, corrected, and scoped-down **Phase 1** of Joe Valentine's throwing implementation — his original commits are cherry-picked here with authorship preserved, plus a fix/scoping pass. Phase 1 lands only the **core gargoyle Throwing skill**; the incomplete content is excised for follow-up PRs (see below).
## What's included (core skill)
- `BaseThrown` combat mechanics on top of the existing skeleton: close-quarters penalty, below-min-range penalty, shield penalty, STR-scaled range, overthrow damage penalty.
- Base weapons: **Boomerang, Cyclone, SoulGlaive** (gargoyle-only), + blacksmith crafting (SA-gated).
- Two symmetric hooks on `BaseWeapon` (`ModifyHitChance`, new `ModifyDamage`) that are inert no-ops for every other weapon.
## Fixes over the original
- **Overthrow damage**: was dead code (the swing gate already guarantees you're within `MaxRange`, so the old `ComputeDamage` check never fired). Reimplemented as `finalDamage × 0.53` applied *after* all offensive bonuses via a new `ModifyDamage` hook, firing at the outer range ring.
- **`DefMaxRange`**: clamped to `[MinThrowRange, MaxThrowRange]` (uncapped before → e.g. range 13 at 200 Str) and guarded against a latent divide-by-zero.
- **Close-quarters mitigation** now uses `RawDex` (matches ServUO/OSI; deterministic under stat mods).
- **Return-throw timer** guarded against a deleted/unmapped thrower/target.
- Reverted the `MovingShot` change (it rebalanced archery — belongs in a separate PR).
- Kept only complex-logic tests (hit-chance/range/damage math); dropped property-value assertions.
## Excised for follow-up PRs (Phase 2/3)
7 named artifacts, the Into-the-Void quest + Agralem, GargishOutcast, the Bladeweaver vendor, and the SA loot tables — these were unwired/non-functional (loot never triggered, quest/creature never spawned) and will return properly wired. `StormCaller` also needs its missing Battle Lust, and the quest its correct void-creature target.
## Verification
- Build: 0 warnings / 0 errors.
- `UOContent.Tests`: **501/501** passing (the `ModifyDamage` hook causes zero regressions across all weapons).
- Full whole-branch review completed: no must-fix defects.
## Summary
Removes the dated `DynamicJson` JSON helper and migrates spawner JSON (de)serialization to a polymorphic `record SpawnerDto` hierarchy. `DynamicJson` was the last remaining consumer (regions moved off it in #1400).
The key correctness improvement: **System.Text.Json deserializes plain DTO records, never a live `Item`.** Previously, deserializing directly into an `Item` meant STJ constructed world-registered objects *before* the data was validated — a malformed/hand-edited spawn file could leave orphaned spawner Items in the world save. Now a parse failure is GC-only; `dto.ToSpawner()` constructs the spawner only from a fully-validated DTO and self-cleans on failure.
## What changed
- **New:** `SpawnerDto` (abstract) + `SpawnerDataDto` / `RegionSpawnerDto` / `ProximitySpawnerDto`, each marked with a reusable `[JsonDiscoverableType]` opt-in attribute. Auto-discovered at the `Configure` phase — no manual registration list (avoids the regions `Register<T>()` footgun), open to custom spawner subtypes.
- **Symmetric mapping:** `BaseSpawner.ToDto()` (export) ⇄ `SpawnerDto.ToSpawner()` (import). `ToSpawner()` deletes-and-rethrows on any failure, so the importer can never orphan an Item.
- **`SpawnerJsonSerializer`** wires `$type` polymorphism on the `SpawnerDto` root with loud collision/constructibility validation.
- **Import/export commands** rewired to the typed DTO path (reflection `FindTypeByName`/`CreateInstance` removed).
- **Data migration:** the 109 `Distribution/Data/Spawns/**` files moved from `"type"`→`"$type"` and legacy `homeRange`→`spawnBounds`. The runtime still *reads* legacy `homeRange` for external files. The `homeRange→spawnBounds` formula is proven equivalent to the runtime conversion (`BoundsEquivalenceTests`, hr=0/1/3/7).
- **Deleted:** `Projects/Server/Json/DynamicJson.cs`.
Sparse export output matches the legacy `ToJson` (nullable DTO properties + `WhenWritingNull`). Binary world-save serialization is untouched.
## Tests
- DTO round-trip per spawner type; sparse-default omission; legacy `homeRange` read; export/import file round-trip.
- `Import_MalformedFile_LeaksNoWorldItems` — proves a mid-array parse failure constructs zero world Items.
- `AllSpawnFilesLoadTests` — every migrated spawn file deserializes and builds.
- Duplicate-discriminator validation.
- UOContent.Tests 485/485, Server.Tests 710/710, build clean.
## Follow-up (not in this PR)
`Rectangle3DConverter.Write` (in `Projects/Server/`) omits `z1/z2` when `Start.Z == -128`, so a future server-side export of a `homeRange`-style spawner round-trips depth 256→255. Pre-existing and out of scope here (Server change); the migrated data reads correctly. Worth a separate small converter PR.
## Problem
Houses and boats (multis) were pathed correctly only by **delegation to the slow path**: `StepCache.TryGetMask` returns `Fallthrough_Multi` for any multi-covered cell, and `GetSuccessors` ran `CheckMovement` **8× per cell** (each re-resolving the tile stack via `GetStaticAndMultiTiles`) — a sustained per-step cost near every house/boat. There was also no automated test pinning multi pathfinding.
This branch is the full multi-pathfinding effort in phases on one branch.
## Phase 1 — characterization tests (the oracle)
Implementation-agnostic invariants: a cache-on≡cache-off whole-path invariant, a per-cell sweep vs `CheckMovement` over footprint+halo (incl. destination Z), hand-verified routing (around walls, demolish-reopens, foundation-redesign-honored), classic-house / foundation / boat fixtures, non-vacuity guards. These gate every later phase byte-for-byte.
## Phase 2 — live single-pass synthesizer
`StepProbe.ComputeMultiMaskAt` synthesizes a covered cell's full 8-direction `StepMask` in one pass (the existing surface/step logic over `GetStaticAndMultiTiles` instead of 8× `CheckMovement`). `GetSuccessors` routes `Fallthrough_Multi` cells through it. No new cache, no `.swb` change. **~1.5×**, zero added allocations.
## Phase 3 / 3.1 — warm per-`multiID` interior cache (airtight)
`MultiMaskCache` caches each fixed multi's local-frame `StepMask` for **interior** cells (cell + all 8 neighbours covered → terrain-neighbour-free → position-invariant), keyed by `multiID & 0x3FFF`, built lazily from the MCL. Interior cells become ~20 ns lookups.
The cache is gated on a **per-instance footprint-clean flag** (`BaseMulti.PathInteriorCacheState`): an instance whose whole footprint terrain is below its floor (`maxTerrain < minFloor`) serves from the cache; a **dirty** instance (terrain intrudes — a contrived/GM placement) **degrades to live-synth, never a wrong mask**. This closes a cross-instance soundness gap (the cached mask depends on neighbour terrain too) found in a holistic review. The gate resets whenever the footprint's world-terrain relationship can change — **location, map, or ItemID** (a boat's heading swaps the MCL).
**Boats are cached too.** Their per-`multiID` deck masks are movement-invariant (built once per heading), so a sailing boat never rebuilds them; only the cheap clean-flag rescan repeats per move (and only when pathed near). Narrow existing boats have little interior; wide galleons (`multi.mul`) would gain Castle-class. `HouseFoundation` (per-instance runtime `DesignState`) is the one type that stays on the live path.
## Verification
- `UOContent.Tests` **454/454**, `Server.Tests` **708/708**, 0 failures.
- The Phase-1 oracle (`MultiPathInvariantTests`, cache-on ≡ cache-off) stays **byte-identical** with the synthesizer + interior cache active.
- Tests pin: footprint-cleanliness (clean vs sunk), dirty/cluttered placement degrades to live-synth while still pathing, clean placement serves, and the gate resets on move/ItemID change.
## Performance (modernuo/ModernUO-Benchmarks#8, full-fixture)
Houses at **Green Acres** (flat staff region → clean footprints, the legit-placement case):
| Route | Slow path | Phase 3.1 (interior cache) | Speedup |
|-------|----------:|---------------------------:|--------:|
| `around_a` (29 steps) | 238.3 µs | **49.1 µs** | **4.85×** |
| `around_b` (29 steps) | 224.3 µs | **49.5 µs** | **4.53×** |
~130 of ~167 multi cells/route serve from the cache (~20 ns) vs 37 live-synth. Per-cell, the slow path's 8× `CheckMovement` grows with multi complexity (GuildHouse ~857 ns → Castle ~1,194 ns), the synthesizer is a flat ~780 ns, and the cache serve is ~20 ns — so big/tall multis (and wide galleons) gain most. Identical allocations throughout.
## Summary
Fixes the pathfinding step-cache (`.swb`) prebake so it bakes **once** and skips when a valid cache already exists, instead of re-baking on every boot. The root cause was the staleness fingerprint hashing mutable in-memory tile data rather than the on-disk files. This PR makes the fingerprint a pure function of the client data files and separates dynamic multis (houses/boats) from the static cache.
> This branch builds on the `ConfigurePrompts` first-boot-prompt unification (commit `5df8d0bd`, also included here) — that commit accounts for the `ServerConfiguration.cs` and `dev-docs/server-lifecycle.md` changes in the diff.
## The bug
With `pathfinding.prebakeMaps` set, the cache re-baked on **every** boot. The `.swb` staleness fingerprint hashed the live `TileData.LandTable`/`ItemTable` flags, which the server patches at runtime (`ItemFixes`, `LOSBlocker`, `PotionKeg`, `CTF`) at nondeterministic lifecycle points (Initialize-phase methods share a priority; static ctors fire lazily). So a fingerprint stamped at runtime (`[PathBake`) never matched the one recomputed during startup `Initialize()`, and the cache rebaked every time.
## Changes
**1. Fingerprint the files, not the in-memory tables** (`fix`)
Hash `tiledata.mul` (cached, computed once) plus the per-map `.mul`/`.uop` files — never the runtime-mutated `TileData` tables. The fingerprint is now lifecycle-stable. Existing `.swb` files rebake once after deploy, then stay stable.
**2. Compute the fingerprint once per boot** (`refactor`)
`Configure()`'s `AutoLoadAtStartup()` already opens and fingerprint-validates a reader for every up-to-date `.swb`. `Initialize()` now skips baking any map that already has an open reader (`StepCache.HasLazyReader`) instead of recomputing the fingerprint a second time.
**3. Bake static-only; route multis to the live path** (`refactor`)
Multis (houses/boats) are dynamic, so they're no longer baked into the static chunk cache — they were tagged with `BuiltMultisVersion`, a non-persisted session counter, which made persisting them unsafe (false matches / wasted re-bakes).
- Chunks bake land + `statics.mul` only.
- At query time, any cell whose sector (or its 1-cell halo) contains a multi routes to `Fallthrough_Multi` → the existing live, multi-aware `CheckMovement` path. The halo prevents a cell proposing a walkable edge into a neighbouring wall; interior (multi-free) cells pay one sector lookup.
- Adds `Sector.HasMultis` (one engine accessor); `.swb` format → v9 (rejects old multi-baked files); new `Fallthrough_Multi` telemetry.
- Behaviour-preserving: multis use the same live path the engine used before the cache existed.
**4. Comment polish** (`style`) — no behaviour change.
## Testing
All green: **92** pathfinding (incl. a new fingerprint-stability test and a multi-halo fallthrough test), **423** UOContent, **708** Server.
## Follow-ups (not in this PR)
- **Background bake worker** — make `[PathBake` and the boot prebake non-blocking (game thread serves tile reads to an off-thread worker).
- **Per-multi MCL cache** — cache walkability in each multi's own frame (keyed by multiID, movement-invariant) so houses/boats get a fast path instead of the live fallback.
- **House-pathfinding equivalence tests** — the one area not yet covered by a dedicated automated test; multi pathing is currently correct by delegation to the live path.
## Summary
Adds authentic **T2A-era (pre-UO:Third-Dawn) packet-based crafting menus**, enabled via the **`t2aCraftMenus` server setting** (read once at startup; default **`!Core.UOTD`**, so a pre-UO:TD shard gets them automatically). When enabled, double-clicking a crafting tool opens the classic `0x7C`/`0x7D` item-list menu — skill- and material-filtered — instead of the modern gump, covering all 8 tool/skill crafts (blacksmithy, tailoring, tinkering, carpentry, alchemy, bowcraft/fletching, inscription, cartography). It is **not** a runtime/admin-flippable feature flag.
This is the **definitive, reconciled** branch and **supersedes**:
- **#2181** (Delphi — `T2A_CraftingMenus`): the original effort.
- **#2381** (Jack/UOLL — `t2a_crafting_menus`): the research-grounded superset (Delphi's base + 12 corrections), rebased onto current `main`.
Original authorship is preserved across the cherry-picked history: foundation commit **@Delphi79**, mechanic fixes **@jackuoll (Jack Ward)**, reconciliation/fixes/docs mine.
## How it was built
1. Cherry-picked Jack's 13 commits onto current `main` (superset of Delphi's; only 2 trivial FeatureFlags conflicts).
2. Applied targeted fixes (below) with tests.
3. Full convention audit, build, and test pass.
Grounded in independent historical research plus Jack's deep dive. Maintainer reference: `dev-docs/t2a-crafting.md`.
## Mechanics (highlights)
- Double-click tool → target resource → skill/material-filtered menu → craft. Resource pre-selection per skill; make-last by targeting the tool.
- **Stacked-gem jewelry:** target a gem stack → the **full stack** is consumed and the piece is named by count ("a 1000 diamond ring"); count persists (`BaseJewel` serialization **v4 → v5**, new `_gemCount`).
- **Tool-less inscription & cartography** (skill-list invoked; no pen/sextant); inscription consumes reagents+scroll on success and failure, mana only on success.
- **Tailoring matching-hue consumption:** targeting hued cloth/leather consumes only that hue. Crafted items take color from their **`CraftResource`** (not the dyed hue), so dyed leather/cloth don't tint the product; in T2A only colored ingots/ore color items (metal armor/shields).
- **Half-resources on failed non-scroll crafts** (pre-UO:TD).
- **Maker's mark** always prompted for exceptional items, via the shared `QueryMakersMarkGump`.
- Server-side menu infra changes are additive (`ItemListEntry.CraftIndex`, `Entries` setter, `HasSent`).
## Notable changes on top of the cherry-pick
- **Toggle is a startup server setting, not a feature flag.** Removed `ContentFeatureFlags.T2ACraftMenus` (and its admin-flippable plumbing); the value is read once via `ServerConfiguration.GetSetting("t2aCraftMenus", !Core.UOTD)` into `T2ACraftSystem.Enabled`. Since the default tracks the era and it can't be flipped at runtime, there's no incoherent "menus-on / UO:TD-era" state.
- **Stacked-gem consumption (B3a/B3):** consume the full `PendingGemCount` (was deliberately consuming 1 while naming by the stack), null-safe gem type, plain-piece fallback + message. New `T2AJewelGemCraftTests`.
- **Convention audit:** `new List<Item>()` → `PooledRefList<Item>` on the hue-aware consume path; removed dead code.
## Decisions & deviations
- `make-last` kept as **QoL** (post-T2A gump-era feature).
- `half-on-failure` (non-scroll) kept as a **reconstruction** (not OSI-confirmed).
- **Stacked-gem** behavior set per shard authority (overrides the "single gem" reconstruction).
- **Cooking** out of scope (no T2A crafting menu existed for it).
- **No colored items from dyed materials:** crafted color comes from the `CraftResource` type. Pre-AOS leather has no colored variant, so leather is always uncolored; weapons retain resource color only in AOS+ (unchanged, intended).
## Test plan
- Automated: `dotnet build ModernUO.slnx -c Debug` clean; `dotnet test Projects/UOContent.Tests` → **421 passed** (incl. 3 new jewelry tests).
- Manual (needs a running T2A shard + client):
- [ ] Each of the 8 skills opens the correct menu; empty-menu guard fires.
- [ ] Make-last repeats the last craft (jewelry re-prompts gem).
- [ ] Jewelry consumes the full targeted gem stack and names by count.
- [ ] Cartography consumes blank maps only with T2A enabled / maps+scrolls when disabled.
- [ ] Tailoring consumes only the targeted-hue material; crafted items are not tinted by dyed cloth/leather.
- [ ] Maker's-mark prompt on exceptional.
- [ ] Failed non-scroll craft consumes half resources.
- [ ] Inscription: reagents+scroll on success/failure, mana only on success.
- [ ] T2A disabled: gump crafting unchanged.
## Credits
Co-authored-by: @Delphi79
Co-authored-by: @jackuoll
## What
On **first boot** (right after map selection), offer to pre-bake the pathfinding `.swb` cache for the selected maps. This removes first-pathfind-after-boot latency and is now cheap — ~18 MB/facet after the v8 format work (the old ~565 MB is gone). The answer persists in `modernuo.json` as **`pathfinding.prebakeMaps`** (default **false**): asked exactly once, and skipped on headless/CI boots (redirected input) where operators can set the flag directly.
## How — a generic startup phase, not pathfinding hardcoded in the engine
The clean-console (pre-Serilog) prompt window is inside the engine startup, but UOContent isn't loaded until after `ServerConfiguration.Load`. So rather than coupling the engine to pathfinding, this adds a generic lifecycle phase:
- **`Main.cs`**: new `AssemblyHandler.Invoke("ConfigurePrompts")` — runs **after** `LoadAssemblies` (so content can participate) but **before** the first `logger.Information` (so console prompts aren't interleaved with the async console sink). The first log line moves below it. Any class can hook in with `public static void ConfigurePrompts()` and self-gate on first-boot state. No `ServerConfiguration` or pathfinding coupling added to the engine.
- **`PathCacheCommands.ConfigurePrompts()`**: the first-boot prompt (interactive-only, flag-absent-only); persists the answer.
- **`PathCacheCommands.Initialize()`** (`Invoke("Initialize")` phase, after the tile matrix loads — which the bake walks): when the flag is set, bakes any map whose `.swb` is **missing or stale** (tile-data fingerprint mismatch, via `StepCache.ComputeLiveFingerprint` / `TryReadFingerprintFromFile`). A fresh cache is a no-op, so only the first boot — or a post-client-update boot — pays the several-minute cost.
## Docs
Fixed the now-stale "~565 MB / ~1.5–2 GB / do not bake by default" section in `dev-docs/pathfinding.md` (it's 17.9 MB for Trammel, tens of MB for all six facets after v8), added a "First-boot pre-bake prompt" section, and added the `pathfinding.prebakeMaps` lever row.
## Verified
- `dotnet build UOContent -c Release` → 0 errors (rebased on #2474).
- Pathfinding/StepCache tests: **90/90 pass**.
- Bootstrap streamlining of the startup phases is intentionally left as a follow-up.
## Summary
Phase #3b (final roadmap item), stacked on #2470. Compacts the index trailer from 20 to 8 bytes/chunk.
Trammel: 19.2 MB → 17.9 MB. Roadmap total: 565 MB → 17.9 MB (−96.8%).
## Details
- Trailer stores `{ u32 packedKey = (ChunkX << 16) | ChunkY, u32 recordLength }` per chunk, in record write order; the file offset is dropped and reconstructed by cumulative recordLength from HeaderSize.
- No record reordering, no varint; fixed-stride, TryReadChunk unchanged.
- Also simplifies the accumulated `.swb` code comments across the stack.
- Format v8; v7 files rejected and re-baked once.
## Tests
v8 multi-chunk round-trip (cumulative offset reconstruction) + the v6/v7 suite; full pathfinding suite green; Release build clean.
## Summary
Phase #3a, stacked on #2469. Compresses each chunk record independently with libdeflate (random access preserved).
Trammel: 124.7 MB → 19.2 MB (−85%).
## Details
- Whole-record framing `[u32 UncompressedLen][payload]`; records that don't shrink (tiny Uniform) are stored raw, detected as payload length == UncompressedLen.
- Codec chosen by full-Trammel spike: libdeflate VeryHigh (16.5 MB, 1.83 µs/chunk decompress) over zstd L19/22 (17.4 MB) and managed Brotli q11 (16.4 MB) — best native ratio, fastest decompress, already the repo's packet codec (no new dependency).
- Reuses cached thread-static bindings: `Deflate.Maximum` for bake, `Deflate.Standard` for reads.
- Compression is bake-time only; decompression is one-time per chunk (LRU-cached).
- Format v7; v6 files rejected and re-baked once.
## Tests
v7 unit tests + the v6 suite run through the compression path; full pathfinding suite green; Release build clean.
## Summary
Phase #2 of the `.swb` step-cache size-reduction roadmap (after #2465, v5 uniform elision). Stores the 16 base directional Z arrays as masked residuals against each cell's own SourceZ and omits any array that matches its prediction. Lossless, byte-identical reconstruction.
Trammel: 231.9 MB → 124.7 MB (−46%).
## Details
- Predictor: `predict = mask bit ? SourceZ : 0` (matches the baker's 0 on unwalkable directions); residual `Z − predict` via unchecked two's-complement (byte-exact for all inputs); reconstruct `Z = predict + residual`.
- A `u16 ZArrayMask` flags which of the 16 base arrays differ from prediction; matching arrays are omitted and synthesized from mask + SourceZ at read.
- Serializer-layer only: StepChunk, the cache, the algorithm, and the baker are unchanged.
- Format v6; v5 files rejected and re-baked once.
## Tests
21 v6 unit tests; full pathfinding suite green; Release build clean.
## Summary
Sub-project #1 of the `.swb` step-cache size-reduction roadmap (`dev-docs/pathfinding.md` § Future work). Adds **uniform-chunk elision** to the `StepCacheFile` format, bumping it **v4 → v5**.
A fully-uniform 16×16 chunk — no strata, **no swim layer**, all 19 base arrays constant (open ocean, Green Acres, void) — serializes to a **~28-byte record** (`KindUniform`) instead of ~5,393, and reconstructs **byte-identically** via `Array.Fill`. Non-uniform chunks use the existing v4 body (`KindFull`) with the swim-layer and strata trailers **fully preserved** — the Kind byte is just prepended.
## Calibrated result (measured, not projected)
Baked Trammel via `SaveToFile`:
| | |
|---|---:|
| Chunks | 114,688 |
| Uniform (swim-aware) → elided | 62.7% |
| Swim-layer chunks (stay Full) | 8.9% |
| Strata chunks (stay Full) | 1.8% |
| Baseline (full records) | 592.2 MB |
| **Actual v5 `.swb`** | **231.9 MB (−61%)** |
The residual is ~150 MB of non-uniform land Z-blocks (targeted by #2 predictive-Z) + ~81 MB of swim-layer trailers (#2/#3). #2 and #3 are separate follow-up PRs.
## Implementation
- `StepChunk.IsUniform()` — false if it has strata **or a swim layer**, else true only when all 19 base arrays are constant (the "all-same" check uses the SIMD-accelerated `ContainsAnyExcept`).
- `StepCacheFile` v5 — `Kind` byte (`KindFull=0`/`KindUniform=2`, 1 reserved); uniform write/read; `FormatVersion`/`MinSupportedVersion` → 5 (v4 files rejected on open and re-baked). No `StepCache`/algorithm/index changes; fingerprint logic untouched.
## Tests
7 `StepCacheFileV5Tests` (uniform round-trip + `<200 B` compactness, varied-full, swim-layer-full, strata-full, swim+strata combined, v4 version-gate rejection) + the existing StepCache/pathfinding suite — **70 pass**, including the prior `SwimLayer_RoundTrips`. An independent review verified write/read symmetry, cast round-tripping, swim/strata preservation, and the version gate (READY TO MERGE).
Fixes#2462
## Summary
Removes the per-object `VirtualHairInfo` heap wrapper for mobile/corpse hair. Hair is now stored **inline** on `Mobile` and `Corpse` as `int _hairItemId` / `int _hairHue` plus a lazily-allocated, **non-serialized** ephemeral `Serial _hairSerial` (in the high virtual-serial range) — and likewise for facial hair. The `VirtualHairInfo` class is deleted, with a **lossless** save migration.
This delivers three things:
1. **Fixes a hair-removal bug.** `Delta(MobileDelta.Hair)` is deferred (it enqueues; `ProcessDeltaQueue` runs later in the tick). The old `HairItemID = 0` setter nulled `_hair` *immediately*, so by the time `ProcessDelta` built the remove packet the equipped virtual serial was already gone — the old `??=` code then re-materialized a **fresh** serial (≠ the equipped one), so clients never removed the right entity, and it left a phantom ItemId-0 object behind. The serial now lives on the entity and **persists across removal**, so remove packets carry the correct serial.
2. **Lightens the entity.** No heap hair object; bald mobiles allocate nothing (the serial is minted lazily only when hair is present). This was the original reason `HairItemID`/`HairHue` exist.
3. **Removes `VirtualHairInfo` entirely**, keeping the high-range virtual serial behavior.
## How
- **Mobile** (manual serialization): inline `_hairItemId/_hairHue/_hairSerial` (+facial); lazy `HairSerial`/`FacialHairSerial`; `ProcessDelta` reads those. Serialization **v36 → v37** — the v30-v37 deserialize is unified, reading the legacy per-hair `VirtualHairInfo` version int only when `version < 37`. Setting item id to 0 clears the hue (matching the old object-nulling) while retaining the serial.
- **Corpse** (codegen serialization): decomposed to `[SerializableField] int _hairItemId/_hairHue` (+facial) + ephemeral serial; **v16 → v17** with `MigrateFrom(V16Content)`.
- **Lossless migration:** the loader validates exact byte length, and the old corpse hair is a presence-bool-gated block, so a tiny **migration-only** `LegacyHairInfo` reader (no runtime role) consumes the legacy `[bool][int ver][int itemId][int hue]` bytes. Frozen `Corpse.v14/v15/v16.json` are retyped to it; `v17.json` describes the new int fields.
- All consumers updated to discrete accessors: `OutgoingMobilePackets`, `CorpsePackets`, corpse subclasses (`MilitiaFighterCorpse`, `SchmendrickApprenticeCorpse`), and the packet test mirrors.
- `VirtualHair.cs` renamed to `OutgoingVirtualHairPackets.cs` (the only type left in it after `VirtualHairInfo` was removed).
## Test Plan
- [x] Full solution build: **0 warnings, 0 errors** (`TreatWarningsAsErrors`).
- [x] `Server.Tests`: **708 passed** (incl. new `RemoveHairUsesEquippedSerial` / `RemoveFacialHairUsesEquippedSerial` proving the serial survives removal + hue clears).
- [x] `UOContent.Tests` corpse/hair: **6 passed** (incl. `CorpseHairMigrationTests` asserting the legacy hair bytes are consumed exactly — the loader's length invariant).
- [x] Generated migration code inspected: V14/V15/V16 readers consume the legacy block byte-for-byte; serial never written to disk.
## Upgrade notes
- Old Mobile (v30–v36) and Corpse (v13–v16) saves load losslessly.
- Minor cosmetic-only change: `SchmendrickApprenticeCorpse` hair/facial-hair RNG draws shift order within each pair (same draw count); irrelevant for a quest NPC corpse.
## Summary
Closes the Cold-cache regression flagged in PR #2450. `StepCache.TryGetMask` no longer eagerly runs `BuildChunk` on the first miss for a chunk that isn't in a `.swb` lazy reader. Instead it returns `Fallthrough_NotBuilt` and the caller (`BitmapAStarAlgorithm`) takes the per-cell slow path. The chunk is only promoted to the bitmap fast path after the **second** miss within a 30-second window, filtering single-touch pass-throughs.
This makes BitmapAStar's worst-case (cold cache + short hops) collapse from **12–47× slower** than FastAStar to **roughly the same**, which is the floor the slow path can deliver. Steady-state warm performance (the actual deliverable) is unchanged from PR-5 — it was always the cache fast path.
## The pet-follow scenario this fixes
A mounted player at ~4 tiles/sec with a pet/hireable following will trigger an NPC pathfind every 100–300 ms. Each pathfind is 1–6 tiles. As the player crosses chunk boundaries (~4 sec/chunk), the pet's first pathfind in the new chunk under the previous behavior triggered a full ~700 µs `BuildChunk` for a chunk the player would leave shortly after. At 50–100 mobiles per shard, this exceeded the 8 ms tick budget. PR-5 BDN data showed scenarios 6–9 (2–8 tile NPC perception) at 2,300–3,700 µs Cold vs FastAStar's 80–200 µs.
Under the new gate:
- First miss → `Fallthrough_NotBuilt` → caller uses slow path (~30–50 µs short path). No `BuildChunk`. No allocation.
- Player keeps moving → chunk never gets a second touch within window → never promoted, no rot.
- NPC patrolling a fixed territory → repeatedly hits the same chunks → second touch within window → promote → cache fast path on subsequent calls.
## What changed
- **`CacheHitKind.Fallthrough_NotBuilt = 6`** + **`CacheStats.FallthroughNotBuilt`** counter. `IsHit=false`, so the caller routes to slow path.
- **`StepCache._chunkMissTracker`** — `Dictionary<long, ChunkMissState>` capped at 4096 entries. State is `(byte missCount, uint lastMissTickStamp)` keyed by chunk key. Window-expired entries reset count to 1; capacity overflow prunes window-old entries first.
- **`StepCache.MissPromotionThreshold`** (default `2`) and **`StepCache.MissPromotionWindowMs`** (default `30_000`) — tunable, can be wired through `ServerConfiguration` if shards want different policy. Setting threshold to `1` restores legacy eager-build behavior (used by tests that prime chunks via single `TryGetMask` call).
- **`StepCache.TryGetMask` miss branch** — try lazy reader first (file-loaded chunks bypass the tracker entirely; an `.swb` represents an explicit prior decision to keep the chunk warm). Otherwise consult the tracker.
- **`BitmapAStarAlgorithm.GetSuccessorsSlowPath`** now layers `IsBlockedByDynamic` on top of `CalcMoves.CheckMovement`. Previously the slow path only ran for `CanFly` creatures and rare cache fallthroughs — `CheckMovement` doesn't iterate same-cell mobiles, so the bitmap fast path's `IsBlockedByDynamic` was the only mobile-blocking check. Now first-touch pathfinds run through the slow path, so the gap had to close.
## Tests
50 pathfinding tests pass (was 47). New / updated:
- **`TryGetMask_FirstTouchOnUnbuiltChunk_DefersBuildAndReturnsFallthrough`** — single TryGetMask call returns `Fallthrough_NotBuilt`, no chunk built, no allocation.
- **`TryGetMask_SecondTouchWithinWindow_PromotesAndBuilds`** — second call inside the 30s window builds + serves.
- **`TryGetMask_SecondTouchAfterWindow_RestartsCounterAndDefers`** — second call outside the window restarts the count, returns Fallthrough again.
- **`TryGetMask_DistinctChunks_TrackedIndependently`** — counters are per-chunk; one touch on each of two adjacent chunks both stay in fallthrough.
- **`LazyReaderHit_BypassesMissTrackerOnFirstTouch`** — open `.swb` + first touch hits without consulting the tracker. Production with `.swb` loaded skips the gate entirely.
- **`MultisVersion_Bump_TriggersDirtyRebuild`** — updated to reflect the new 3-step flow (Fallthrough → Miss_NotBuilt → Miss_DirtyRebuild).
- Tests that prime chunks via a single `TryGetMask` call (multi-Z, Tier4, lifecycle, parity, BitmapAStar uses-cache) set `MissPromotionThreshold = 1` to opt into eager behavior.
## Expected BDN impact
The Cold column from PR-5's BDN should change as follows once the bench's submodule pointer is updated to this branch:
| # | Scenario | Cold (PR-5) | Cold (PR-6 expected) | FastAStar Cold |
|--:|-----------------|-------------:|---------------------:|---------------:|
| 2 | sewer corridor | 1,627 µs | ~36 µs | 36 µs |
| 4 | causeway | 1,533 µs | ~39 µs | 39 µs |
| 6 | pet 2-tile | 2,364 µs | ~80 µs | 81 µs |
| 8 | npc 5-tile | 3,708 µs | ~140 µs | 141 µs |
| 9 | npc 8-tile | 2,386 µs | ~200 µs | 197 µs |
WarmNoFile and LazyWarm rows should be unchanged — they were always cache-warm. The miss tracker only fires when neither resident chunks nor the lazy reader can satisfy the request.
## Future work (not in this PR)
- **Background-thread bake**: builds outside the game thread so even promoted chunks don't pay the 700 µs build cost on the main thread. Rule 10 (no Task.Run) applies, so this needs careful design — the bake is a pure data transform but main-thread synchronization on chunk-state transitions has to be threaded through. Defer to a follow-up.
- **Long-traverse BDN scenario**: a multi-Find benchmark simulating 50 pet repaths across chunk transitions. Requires restructuring the bench harness; the existing 10-scenario corpus + Cold provider already exercises the gate.
- **Swim sourceZ bake**: scenario 5 (sea serpent) shows 56 B alloc on warm paths because the cache's SourceZ is computed under default-walker rules. Swim creatures fall through to slow path. Independent of this PR.
## Summary
Creatures (pets following, monsters chasing, NPCs approaching) would **oscillate — "pace back and forth really fast"** at concave obstacles (reported at the Britain Inn L-desk: a pet at `(1493,1614,20)` never reaching its master at `(1494,1605,21)`) instead of routing around them.
**Root cause** (the A* pathfinder itself was correct): all goal-seeking funnels through `MoveTo` and `WalkMobileRange` → `MoveTowardsOrAwayFrom`, which step greedily via `DoMove(dir, badStateOk:true)`. `DoMove` returns `true` even when the direct step was blocked and the creature merely **auto-turned and sidestepped** (`MoveResult.SuccessAutoTurn`), and the caller then set `Path = null`, discarding the `PathFollower`. So at a concave obstacle a non-progressing sidestep was mistaken for progress and the creature never committed to a route. (AOS pet-follow runs at `CurrentSpeed = 0.1`, hence the "really fast" shuffle.)
## What changed
- **New centralized `BaseAI.ApproachTarget(target, run, range)` primitive.** A greedy step is committed only when it **fully succeeds (`MoveResult.Success`) and actually gets closer**; otherwise the creature commits to a **persistent `PathFollower`** that routes around the obstacle and is never discarded by a greedy step. The open-terrain fast path (one greedy step, no pathfinding) is preserved. `MoveTo`, `MoveTowardsOrAwayFrom`, and `MoveToWithCollisionAvoidance` all delegate to it — public signatures unchanged, so no AI-class call site changes.
- **Best-distance give-up + idle.** A creature that cannot reach a **stationary** in-range goal stops shuffling and idles after `ApproachGiveUpTicks` (40) ticks without lowering its closest-ever distance; a **moving** goal (active chase) never gives up. It resumes the moment the goal moves.
- **Pathfinder fix (required):** `BitmapAStarAlgorithm.IsBlockedByDynamic` now skips the dynamic mobile-block check **at the goal cell only** (`MoveImpl.Goal`). Previously A* returned `null` whenever the target mobile stood on the goal cell, so creatures could never pathfind *toward* another mobile — only toward empty ground. The follower stops within `range` short of it. Static/item blocking and all non-goal mobile blocking are unchanged.
## Tests
New AI-loop integration tests in `ApproachTargetTests.cs` drive the real `BaseAI` primitives against live Britain Inn map statics: exact-repro pet follow, open-terrain (asserts zero pathfinding), `MoveTo` chase (static + walking-away target), route-around-a-dynamic-wall, and walled-off give-up-and-idle.
- Pathfinding + AI subset: **52/52** pass.
- Full `UOContent.Tests`: **301/301** pass. (Note: the test host lingers on shutdown — a pre-existing infra quirk unrelated to this change; all tests complete and pass.)
- Full solution build: clean (0 warnings / 0 errors).
## Notes
- Branched off `main`; independent of the in-flight step-cache work.
- Out of scope (future work): proactive "SmartAI" look-ahead pathfinding so clever creatures plan a route before walking into the obstacle, rather than reacting after they hit it.
## Test Plan
- [X] In-game: order a pet to `follow`/`come` across the Britain Inn L-desk; confirm it routes around and reaches you instead of pacing.
- [X] Aggro a monster and kite it around a building/treeline; confirm it chases around obstacles.
- [X] Confirm open-terrain following/chasing feels unchanged (no extra latency).
- [X] Confirm a creature with a genuinely unreachable target idles rather than shuffling forever.
## Summary
Multi-Z cells (bridges, stairs, paver-over-ground, multi-floor structures) now carry **per-stratum walkability data** in the cache instead of falling through to the slow path. The data is computed at chunk-build time, persisted in the `.swb` file, and selected at query time by matching the request's `sourceZ` against each stratum's `zCenter` (within `StepHeight` tolerance).
This is the Tier 4 strata feature, deferred from PR #2447 / PR #2448 / PR #2449. Builds on PR #2449's lazy backing store and public bake helpers.
## Wire format change (v1 → v2)
`StepCacheFile.FormatVersion = 2`. `MinSupportedVersion = 2`. v1 `.swb` files are silently rejected at open time (treated as missing) and overwritten on the next `SaveToFile` / `BakeMap`. **No migration** — older files just get re-baked.
The `MinSupportedVersion` sentinel is the model going forward: bump the constant when an incompatible change lands; admins re-bake on the next deploy. No matrix of v1↔v2↔v3 migration logic to maintain.
## What changed
- **`StepProbe.ComputeStrataAt(map, x, y)`** — enumerates walkable standing-Zs at the cell (one per land surface plus one per walkable static), collapses Zs within `2*StepHeight`, runs `ComputeMaskAt` at each surviving Z. Returns `null` for single-Z cells (caller uses the chunk's main mask).
- **`StepChunk`** — replaces the old `MultiZCells` bitmap with a **strata storage pair**:
- `ushort[256] StrataOffsetByCell` (sentinel `NoStrata = 0xFFFF` = "no strata for that cell")
- `byte[] StrataData` packed: `u8 stratumCount`, then `count × 19-byte stratum`
- `sbyte zCenter, byte walkMask, byte wetMask, sbyte walkZ_N..NW (8), sbyte swimZ_N..NW (8)`
- `IsCellMultiZ` derives from `StrataOffsetByCell[cell] != NoStrata` — same semantics, single source of truth.
- **`StepCache.BuildChunk`** — populates strata for cells flagged multi-Z via `SetStrata`. Chunks with zero multi-Z cells pay zero strata overhead (offset array + data array stay null).
- **`StepCache.TryGetMask`** — for multi-Z cells, scans strata with `TryStratumHit`; returns the matching one with `HitKind=Hit`. Falls through to slow path only when no stratum matches the query `sourceZ`.
- **`StepCacheFile`** — v2 serialization with strata trailer per chunk + `recordLength` in index entry. Lazy reader sizes scratch per-chunk-record using the recorded length, growing on demand for multi-Z-heavy chunks. Patches `IndexOffset` on `w.Buffer` (BufferWriter's current backing array) since it grows during variable-size chunk writes.
## File layout v2
```
Header (48 bytes):
u32 Magic = 0x42575300 ('SWB\0')
u32 Version = 2
u32 MapId
u64 Fingerprint XxHash3 over LandTable + ItemTable flags + map files (mapX.mul/.uop, staidxX.mul, staticsX.mul)
u64 BakeTimestamp informational
u32 ChunkCount
u64 IndexOffset position where chunk index begins
Per chunk (variable size):
u16 ChunkX, ChunkY
u32 BuiltMultisVersion
u8 HasStrata 0 = no strata trailer; 1 = strata trailer follows
byte WalkMask[256], WetMask[256]
sbyte SourceZ[256], WalkZN..WalkZNW[256], SwimZN..SwimZNW[256]
// Strata trailer (only when HasStrata == 1):
u16 StrataOffsetByCell[256] // NoStrata sentinel = 0xFFFF
u32 StrataDataLength
byte StrataData[StrataDataLength]
Per multi-Z cell: u8 count, then count × Stratum (19 bytes)
Index trailer (20 × ChunkCount bytes):
per chunk: { u64 chunkKey, u64 fileOffset, u32 recordLength }
```
## Summary
Adds two pieces of pathfinding tooling on top of PR #2448's lazy `.swb` infrastructure:
- **`PathfindRecorder`** — admin-toggled JSONL telemetry capture; one record per `BitmapAStarAlgorithm.Find` call. Output format matches the BDN harness corpus, so production traffic can be captured and replayed in benchmarks without an adapter.
- **Public bake helpers on `StepCache`** — `ComputeLiveTileDataHash`, `TryReadTileDataHashFromFile`, `BakeMap`, `ClearResidentChunks`. Lets the benchmark project (and any future bake utility) drive cache fill + persist without exposing internal types.
The companion BDN harness update lives in [ModernUO-Benchmarks#kb/pathfinding-pr4-bench](https://github.com/modernuo/ModernUO-Benchmarks/tree/kb/pathfinding-pr4-bench): porting `Benchmarks/PathfindInGame/` from the `kb/ai_pathfinding` branch to the API shipped in #2446–#2448.
## What's in this PR
### `PathfindRecorder` (`PathfindRecorder.cs`)
- Holds a single `StreamWriter` open while recording; its internal buffer absorbs per-record writes without per-call `File.AppendAllText`.
- Single `bool` check on the hot path; cheap when disabled.
- Disabling flushes + disposes; an IO failure during write also disables the recorder.
- Server config:
- `pathfinding.recorder.enable` — bool, default `false`. Read on boot via `GetOrUpdateSetting`.
- `pathfinding.recorder.path` — default `<basedir>/Data/Pathfinding/recordings/pathfinds.jsonl`.
- Hooked into `BitmapAStarAlgorithm.Find` — runs once per call, does nothing when disabled.
- Admin command: `[PathRecord [on|off|flush|status]` (default `status`).
### Public cache helpers
- `static ulong StepCache.ComputeLiveTileDataHash()` — wraps the file module's hash function for staleness checks.
- `static bool StepCache.TryReadTileDataHashFromFile(string, out ulong)` — peeks at a `.swb` file's hash field (20 bytes).
- `int StepCache.BakeMap(int, string)` — walks every chunk in the map, populates resident set, saves. Offline / fixture use; blocks for many seconds on a full-map walk.
- `void StepCache.ClearResidentChunks()` — drops chunks + zeros counters but keeps lazy readers open. Lets benchmark loops measure "first query after boot" cost across iterations without the lazy-reader reopen overhead.
## Summary
Adds a binary disk format + lazy reader so the step cache can warm-start from a precomputed file without paying chunk-build cost on the first pathfind through a region. **Resident memory stays bounded by `MaxResidentChunks` regardless of file size** — opening a `.swb` reads only the header + chunk-offset index (~16 bytes per indexed chunk), and individual chunks are seeked + deserialized only when `ResolveMissingChunk` asks for them.
The lazy design (vs. an eager bulk load): a 250 MB bake on a RAM-constrained shard never materializes more than the LRU cap (~40 MB at the default 8192-chunk cap), and unwanted regions never enter memory at all.
Builds on PR #2447.
## What changed
- **`StepCacheFile`** — binary reader/writer module. Writer emits header → chunks (offsets recorded) → index trailer, then patches the header's `IndexOffset` field. Reader is `OpenForLazy(path)` returning a `LazyReader` that holds an open `FileStream` + offset dictionary.
- **`StepCacheFile.LazyReader`** — `TryReadChunk(chunkX, chunkY)` does a single seek + bulk read for one record. `Dispose` releases the underlying stream. Files are opened with `FileShare.Read | FileShare.Delete` so admin tooling can replace them.
- **TileData fingerprint via XxHash3.** The `.swb` header carries a hash of `LandTable + ItemTable` flags. Load rejects any file whose hash doesn't match the running server. Computed via `HashUtility.ComputeHash64` (engine-blessed hasher) — adds a `ReadOnlySpan<byte>` overload alongside the existing `ReadOnlySpan<char>` one for parity.
- **`StepCache.SaveToFile(path, mapId)`** — writes resident chunks for the given map.
- **`StepCache.TryOpenLazyReader(path, mapId)`** — opens the file, validates header, holds the reader for the map's lifetime.
- **`StepCache.ResolveMissingChunk`** — now consults the lazy reader before invoking the runtime baker. A loaded chunk whose `BuiltMultisVersion` doesn't match the live sector falls through to the baker (snapshot was made before a multi was added/removed in that sector).
- **`StepCache.Clear` closes lazy readers.** Test cleanup can delete `.swb` files cleanly.
- **Auto-load at startup.** `PathCacheCommands.Configure()` opens `Data/Pathfinding/<mapId>.swb` as a lazy reader for every map.
- **`[PathCacheSave`** / **`[PathCacheLoad`** — admin commands for the same workflow.
- **`pathfinding.maxResidentChunks` shard-tunable.** Read from `server.cfg` at boot via `ServerConfiguration.GetOrUpdateSetting` (default 8192 ≈ 40 MB). Small shards can tune down; large shards with substantial bakes can tune up to reduce eviction churn. Default is written back to `server.cfg` on first boot, matching the engine pattern used by other settings.
## File layout (v1)
```
Header (48 bytes):
u32 Magic = 0x42575300 ('SWB\0')
u32 Version = 1
u32 MapId
u64 TileDataHash XxHash3 over LandTable + ItemTable flags (HashUtility)
u64 BakeTimestamp informational
u32 ChunkCount
u64 IndexOffset file position where the chunk index begins
Chunk records (fixed size, ~5,393 bytes each, +32 if multi-Z):
u16 ChunkX
u16 ChunkY
u32 BuiltMultisVersion
u8 HasMultiZ
byte WalkMask[256], WetMask[256]
sbyte SourceZ[256], WalkZN..WalkZNW[256], SwimZN..SwimZNW[256]
[byte MultiZCells[32] when HasMultiZ == 1]
Index trailer (16 × ChunkCount bytes):
(u64 chunkKey, u64 fileOffset)
```
## Memory math
| Scenario | Disk file | RAM at boot | Notes |
|---|---|---|---|
| Empty / no `.swb` files | — | 0 | Silent; cache builds on demand. |
| Admin-curated towns (5K chunks) | 25 MB | 0 + per-query | Index ≈ 80 KB. Resident grows to the configured cap under steady-state queries. |
| Full-map bake (50K chunks) | 250 MB | 0 + per-query | Index ≈ 800 KB. Same configured cap. Cold areas never load. |
| All 5 maps fully baked | 1.25 GB | 0 + per-query | Index ≈ 4 MB total. Same configured cap. |
## Hash choice (FNV-1a → XxHash3)
The original draft used inlined FNV-1a-64. Switched to XxHash3 via `HashUtility`:
- ~30× faster on this workload (~30 GB/s SIMD vs ~2 GB/s byte-by-byte). Boot-time only, so absolute saving is microseconds — the real wins are elsewhere.
- Stronger collision resistance and distribution.
- Drops ~25 lines of inlined hash code; matches the rest of the codebase's hashing pattern.
- Hash is stable as long as `HashUtility`'s `xxHash3Seed` constant doesn't change (already marked `// DO NOT CHANGE THIS NUMBER`).
## Summary
Builds on PR #2446's cache-direct A*. The previous PR conservatively routed players + creatures with capability flags entirely through the slow path. This PR pushes that line: most mobile classes now use the cache, with the right rule set layered on top per-mobile, and the cache fast-path now does the dynamic items / mobiles check that PR #2446 had silently skipped.
## What changed
- **Non-GM players** now use the cache. Diagonal corner-cut applies the strict AND-rule (BOTH cardinal partners walkable) by reading the same source-cell mask byte the creature OR-rule reads — both rules are evaluable from one byte.
- **Creatures with `CanOpenDoors` / `CanMoveOverObstacles`** now use the cache. Reading `MovementImpl` confirmed those flags only affect dynamic items, never static tiles, so they were over-conservatively excluded before.
- **Swim creatures** now use the cache via a capability overlay. `StepProbe` bakes a second rule set (`canSwim=true, cantWalk=true`) producing `WetMask` + `SwimZ_*`. The algorithm composes `effectiveMask = (walkMask & !cantWalk) | (wetMask & canSwim)` per direction; walk Z preferred when both apply.
- **Dynamic-obstacle pass.** Cache fast-path now mirrors `MovementImpl`'s per-cell items + mobiles collision check (`GetItemsAt` / `GetMobilesAt` at the target cell, with `CanOpenDoors` / `CanMoveOverObstacles` / spell-field overrides). This closes a correctness gap from PR #2446 — the cache fast-path was silently skipping dynamic obstacles entirely.
- **`StepCache.TryGetMask` returns `StepMask` struct** instead of 11 out parameters. `HitKind` rolls into the struct with an `IsHit` accessor. Sets up wet/swim without ballooning the call site.
- **`StepChunk.MultiZCells` is lazy-init.** Most chunks are entirely single-Z; allocating the 32-byte bitmap up-front wasted ~256KB at full cap.
- **Admin commands.** `[PathCacheStats` (resident chunks + hit/miss/eviction counters) and `[PathCacheClear` (drop everything, zero counters).
- **Feature flag.** `bitmap_pathfinding_cache` (default true) gates the cache fast-path. Flipped off, every cell expansion routes to `MovementImpl` — equivalent to PR #2446's slow-path-only behavior. Safety net for shipping the new behavior.
`RequiresSlowPath` shrinks to just `CanFly` — flying creatures Z-jump arbitrarily, which the cache's static-Z model can't accommodate.
## Summary
Replaces `FastAStarAlgorithm` with `BitmapAStarAlgorithm`: one cache lookup per cell expansion (8-direction mask + per-direction destination Z) instead of 8 separate `MovementImpl.CheckMovement` calls. Adds the supporting cache infrastructure to back it.
Public API unchanged — `MovementPath` / `Mobile.Move` / `CalcMoves.Find` return the same shapes; the algorithm swap is internal.
## What's in this PR
- **`BitmapAStarAlgorithm`** — A* that issues one `StepCache.TryGetMask` call per cell expansion. Inline fallthrough to the per-cell slow path for multi-Z, off-map, source-Z mismatch, and non-default walkers.
- **`StepCache`** — singleton chunk store keyed by `(mapId, chunkX, chunkY)`. Lazily built on first query, invalidated by `Sector.MultisVersion` mismatch, memory-bounded by sampled probabilistic LRU.
- **`StepProbe`** — computes static-only walkability for a single cell, mirroring `MovementImpl.Check` minus the item / mobile collision phases.
- **`StepMask` / `StepChunk`** — value / storage types for the per-cell results.
- **`CacheEvictionTimer`** — periodic cap backstop (60s interval; early-returns when not over cap).
- **`Map.Sector.MultisVersion`** promoted to `public` so the cache can detect dynamic-static invalidations cheaply.
## Eviction strategy
Sampled probabilistic LRU (Redis-style). Per eviction, sample 5 random keys from a parallel `List<long>` kept in lockstep with the chunk dictionary; evict the oldest of the sample via swap-and-pop. O(1) per eviction regardless of resident count, so sustained cap pressure has no perpetual perf hit.
## Capability handling (interim)
Non-default walkers (non-GM players, creatures with `CanSwim` / `CanFly` / `CanOpenDoors` / `CanMoveOverObstacles`) route entirely through the per-cell slow path via `BitmapAStarAlgorithm.GetSuccessorsSlowPath`. The 2-pass design (cache + capability overlay + dynamic-obstacle pass) lands in the follow-up PR.
Adds an opt-in 'youngPlayerSystem.enabled' server setting (default true) that, when set to false, disables the Young player system server-wide:
- Account.Young and PlayerMobile.Young getters short-circuit to false.
- New characters no longer receive Young status or a NewPlayerTicket.
- All downstream Young checks (notoriety beneficial-action restriction, CheckYoungProtection, stealing penalties, YoungDeathTeleport, death-item movement, poison immunity, '(Young)' name suffix, CanLogout, renounce-young keyword/gump, BaseCreature.OnDeath fame penalty, OnLogin time-remaining message) become inert.
Setters are intentionally left untouched so serialized account/player flags round-trip cleanly when the setting is later re-enabled.
## Summary
Phase 3.3 of the message-interpolation cleanup. Eliminates the `rank.ToString().ToLower()` two-allocation pattern in ConPVP trophy-award messages.
- Adds `TrophyRank.LowerName()` extension returning a static lowercase string per enum value via switch expression.
- Updates 10 call sites across Tournament, KingOfTheHill, DoubleDom, CTF, BombingRun (2 each - cash and no-cash branches).
The handler now appends a static interned string directly into the packet buffer; no `ToString()` formatter and no `ToLower()` allocation per call. Source comment in BombingRun.cs ("There is no formatting flag for Lowercase, we may need a custom interface to get rid of it") is now resolved at the call-site level.
## Summary
Phase 3 PR B of the message-interpolation cleanup. Handles the multi-line restructure sites flagged in `dev-docs/string-handling-message-interp-audit.md` (Phase 2). Phase 3.1 (PR #2436) handled trivial sweeps; this PR handles sites that needed an `if/else` hoist or switch restructure to eliminate `string.Format` while preserving exact message text.
Each site previously allocated an intermediate `string.Format(...)` result before passing to the message handler, despite Phase 1 making the handler accept interpolated string handlers natively.
## Sites fixed
- **`Projects/Server/Mobiles/Mobile.cs:7911`** - Title/guild header was using `string.Format` with a conditional template (`"[{1}]{2}"` vs `"[{0}, {1}]{2}"`). Split into `if (title.Length <= 0)` / `else` with direct `$"..."` interpolation.
- **`Projects/UOContent/Engines/ConPVP/DuelContext.cs:1337`** - View-ladder rank text used `string.Format(text, from == pm ? "You" : "They")`. Split into `if (from == pm)` / `else` with direct `$"..."` interpolation in each branch.
- **`Projects/UOContent/Engines/ConPVP/DuelContext.cs:1463`** - Showladder text reused a single format string for both `LocalOverheadMessage` ("You ... are ...") and `NonlocalOverheadMessage` ("`{pm.Name}` ... is ..."). Each call now uses an inline `$"..."` directly; no shared template.
- **`Projects/UOContent/Engines/ConPVP/Gumps/ConfirmSignupGump.cs:518`** - The signup confirmation message used a `switch` expression assigning a literal format string to `fmt`, then `string.Format(fmt, from.Female ? "Lady" : "Lord", timeUntil)`. Converted to a `switch` statement where each case calls `_registrar.PrivateOverheadMessage(...)` directly with an inline `$"..."`. Lady/Lord branching is hoisted to a `title` local.
## Exempted
- **`Projects/UOContent/Engines/ConPVP/Participant.cs:138`** - The `nonLocalOverhead` format string is a parameter passed in by callers of `Participant.Broadcast`. Investigation found 5 call sites in `DuelContext.cs` (lines 782, 802, 1187, 1196, and three at 1535/1564/1608) that pass distinct literal format strings. Refactoring would require changing all 5 callers and the method signature - out of scope for this PR. Marked with a `// Phase 3 audit:` comment per the audit's exemption convention.
## Summary
Phase 3.1 of the message-interpolation optimization series. Fixes 9 of the 28 sites flagged in the Phase 2 audit (PR #2435):
| File | Fix |
|---|---|
| `Commands/StaffAccess.cs:88,99` | Drop redundant `.ToString()` on enum holes |
| `Commands/Handlers.cs:102` | `builder.ToString()` -> `builder.AsSpan()` |
| `World Saves/SaveCommands.cs:71-75` | Merge 3 concatenated `$"..."` into one literal |
| `Server/Items/Item.cs:4213` | Hoist nested ternary `$"..."` to if/else |
| `Engines/Factions/Mobiles/Guards/BaseFactionGuard.cs:140-150` | Convert switch expression to switch statement |
| `Mobiles/Monsters/LBR/Jukas/JukaLord.cs:85` | Restructure `string.Format(toSay.RandomElement(), ...)` into switch |
| `Misc/AttackMessage.cs:30-41` | Inline `AggressorFormat`/`AggressedFormat` constants |
No functional changes. Each site emits identical text; the only difference is that the message string is now built into a pooled char buffer instead of being allocated as a `string` first.
## Summary
Phase 1 of a multi-phase optimization to eliminate intermediate string allocations between `$"..."` interpolation and the packet text region for ModernUO's player-facing message APIs.
- Adds `[InterpolatedStringHandler]` overloads to every `Send*`/`Public/Local/Private/NonlocalOverheadMessage`/`Say`/`Emote`/`Whisper`/`Yell`/`SendLocalizedMessageTo` API in `OutgoingMessagePackets`, `Mobile`, and `Item`. Each overload is a 3-line shim that forwards `handler.Text` to the existing span-based path then calls `handler.Clear()` to return the rented `STArrayPool<char>` buffer (matches the established `SpanWriter.WriteAscii(ref RawInterpolatedStringHandler)` precedent).
- Converts `string text/args/affix/name` parameters to `ReadOnlySpan<char>` for consistency with the handler path. `lang` intentionally stays `string` (it's never interpolated and the `??= "ENU"` fallback stays cleaner).
- Adds `int charCount` overloads of the three `GetMaxMessage*Length` helpers so stackalloc sizing can avoid the redundant `ROS<char>` round-trip.
- Moves `Mobile` (17 methods) and `Item` (4 methods) message methods into new partial-class files (`Mobile.Messages.cs`, `Item.Messages.cs`) for organization.
No UOContent call sites change in this PR — existing `string`/`ROS<char>` calls compile unchanged via implicit conversion. Phase 2 (intermediate-string audit) and Phase 3 (cleanup PRs) follow.
## Files
- `Projects/Server/Network/Packets/OutgoingMessagePackets.cs` — `string` → `ROS<char>` for text params, `int charCount` length helpers added, class made `partial`
- `Projects/Server/Network/Packets/OutgoingMessagePackets.Interpolated.cs` (new) — 3 `ref RawInterpolatedStringHandler` extension overloads
- `Projects/Server/Mobiles/Mobile.cs` — message methods extracted (-262 lines)
- `Projects/Server/Mobiles/Mobile.Messages.cs` (new, 463 lines) — moved + ROS-converted methods + 25 handler overloads
- `Projects/Server/Items/Item.cs` — message methods extracted (-93 lines)
- `Projects/Server/Items/Item.Messages.cs` (new, 142 lines) — moved + ROS-converted methods + 4 handler overloads
- `Projects/Server.Tests/Tests/Network/Packets/Outgoing/MessagePacketTests.cs` — 3 new regression tests verifying byte-equivalence for the handler overloads
## Summary
Migrates 14 ConPVP lobby/tournament gumps from legacy `Gump` to modern `DynamicGump`/`StaticGump<T>`. Layouts move into `BuildLayout(ref DynamicGumpBuilder)`, constructors become private, and validation moves into static `DisplayTo` entry points (empty-gump rule).
**Per-gump base type decisions:**
- `BeginGump` → `StaticGump<BeginGump>`: layout is fully fixed (no dynamic content). All other gumps below are `DynamicGump` because they bake dynamic player names, guild abbreviations, ruleset titles, arena names, tournament participant names, ladder rankings, or per-instance rule modifications. Per the cliloc/dynamic-text rule, dynamic content forces `DynamicGump`.
- `ReadyGump`, `ReadyUpGump` → `DynamicGump` (per-instance participant rosters).
- `AcceptDuelGump`, `AcceptTeamGump`, `ConfirmSignupGump` → `DynamicGump` (challenger/registrar/team names, dynamic rule modifications).
- `PickRulesetGump`, `RulesetGump` → `DynamicGump` (ruleset titles and option labels per instance).
- `ParticipantGump`, `DuelContextGump` → `DynamicGump` (player rosters/team labels).
- `LadderGump` → `DynamicGump` (ladder entries: ranks, levels, guild abbrs, names, wins/losses).
- `ArenaGump` → `DynamicGump` (arena names with active player names).
- `PreferencesGump` → `DynamicGump` (arena name list).
- `TournamentBracketGump` (~1k LOC) → `DynamicGump`. The whole gump is one type-switched view that re-renders on every button press across `Index`, `Rules_Info`, `Participant_List`, `Participant_Info`, `Round_List`, `Round_Info`, `Match_Info`, `Player_Info`. All branches bake per-instance content.
**Refresh-via-this conversions (the big perf wins):**
- `LadderGump`: page +/- now mutates `_page` and calls `from.SendGump(this)` instead of allocating a new `LadderGump`.
- `PickRulesetGump`: ruleset apply / flavor toggle now refreshes via `this`.
- `ParticipantGump`: increase/decrease team size, remove player, target failure all refresh via `this`.
- `DuelContextGump`: failed-start and add-participant refresh via `this`.
- `ConfirmSignupGump`: every signup-validation rejection branch in `OnResponse` and every `AddPlayer_OnTarget` rejection branch refreshes via `this` (was allocating a new gump per branch).
- `TournamentBracketGump`: every navigation button (back/forward, type change, page change, drill-down) mutates `_type`/`_object`/`_list`/`_page` and refreshes via `this`. Previously each click allocated a new 1k LOC gump.
All gumps are `Singleton`, use private constructors with static `DisplayTo` entry points that null-check `NetState` before allocation. External callers in `DuelContext`, `TournamentBracketItem`, `TournamentController`, `TournamentSignupItem`, and the cross-references between `AcceptDuelGump`/`ParticipantGump`/`AcceptTeamGump`/`ConfirmSignupGump` are all updated to use `DisplayTo`. Legacy `m_X` fields renamed to `_x` per coding standards.
## Summary
Migrates the four ConPVP game board (scoreboard) gumps from legacy `Gump` to `DynamicGump`:
- **`BRBoardGump`** (Bombing Run) — variable layout: row-per-team based on `Participants.Count`. Migrated to `DynamicGump`, `Singleton`, private constructor + `DisplayTo`, `SetNoClose()`.
- **`CTFBoardGump`** (Capture the Flag) — variable layout: row-per-team filtered to only teams with a flag. Same migration shape.
- **`DDBoardGump`** (Double Domination) — variable layout: row-per-team. Same migration shape.
- **`KHBoardGump`** (King of the Hill) — variable layout: row-per-team. `sealed`. Same migration shape.
### Refresh-via-this decision
For all four boards, **score data lives on the `*Game` / `*TeamInfo` objects, not the gump**. The gump just renders a snapshot of those values at the moment it is sent. The three call sites per board are:
1. `OnDoubleClick` on the in-world scoreboard item — one-shot manual open.
2. After death/kill score events (in `OnDeath`) — game logic pushes a fresh board to the dying player so they see updated scores.
3. End-of-game broadcast loop — sends final results to every participant.
None of these are button-driven refreshes from inside the gump, and the gump owns no mutable state. Therefore each event allocates a fresh gump (now via `DisplayTo(...)`) rather than calling `SendGump(this)` on a long-lived instance — that pattern doesn't fit when the data source is external. The win comes from `DynamicGump`'s ref-struct builder writing directly to buffers, eliminating the legacy `GumpEntry` list allocations on every send.
### Mechanics
- `: Gump` → `: DynamicGump`; layout moved from constructor to `BuildLayout(ref DynamicGumpBuilder)`.
- `Closable = false` → `builder.SetNoClose()`.
- Constructors are `private`; static `DisplayTo(Mobile, *Game, ...)` validates `mob?.NetState != null && game != null` before constructing.
- Team-section-mode parameter (`section`) preserved on BR / CTF / DD as an optional `DisplayTo` param even though no current caller uses it.
- The four `m_Game` / similar fields are renamed to `_game`; new fields use `_camelCase` per CLAUDE.md §12.
- `AddBorderedText` / `AddColoredText` helpers became `static` and take `ref DynamicGumpBuilder`.
- Updated all 12 internal call sites (3 per file) to go through `DisplayTo`. No external callers.
- No `OnResponse` was defined on any of these gumps (the only button is a close button), so no `RelayInfo` signature changes were needed.
Touches 4 game files, but only the gump classes — game logic (BR death/scoring, CTF flag handling, DD domination, KH king timer) is untouched.
## Summary
Migrates the Quest system gumps from legacy `Gump` to `DynamicGump` / `StaticGump<T>`.
**Renames** `Engines/ML Quests/Gumps/BaseQuestGump` to **`BaseMLQuestGump`** to
disambiguate from the Core quest abstract (`Engines/Quests/Core/QuestSystem.cs`).
Both abstracts now extend `DynamicGump`.
**Abstract bases**:
- `Server.Engines.Quests.BaseQuestGump` (Core) - now `abstract DynamicGump`. Holds constants and a static `AddHtmlObject(ref DynamicGumpBuilder, ...)` helper. Concrete subclasses each provide their own `BuildLayout`.
- `Server.Engines.MLQuests.Gumps.BaseMLQuestGump` (ML, renamed) - now `abstract DynamicGump` with a `protected abstract BuildContent(ref DynamicGumpBuilder)` hook. The base's `BuildLayout` draws shared chrome (background art, frame, label header) and then invokes `BuildContent`; subclasses use `BuildPage`, `SetTitle`, `RegisterButton`, `SetPageCount`, and content helpers (`AddDescription`, `AddObjectives`, `AddObjectivesProgress`, `AddRewardsPage`, `AddRewards`, `AddConversation`).
**Concrete Core gumps** migrated to `DynamicGump`:
- `QuestCancelGump`, `QuestOfferGump` (Core), `QuestObjectivesGump`, `QuestConversationsGump`, `QuestLogUpdatedGump`, `QuestItemInfoGump`, `SheetMusicOfferGump` (Impresario), `PaintedImageGump` (renamed from `PaintedImage.InternalGump`).
**Concrete ML gumps** migrated to `DynamicGump` (extending `BaseMLQuestGump` or directly):
- `InfoNPCGump`, `QuestConversationGump`, `QuestLogDetailedGump`, `QuestLogGump`, `QuestOfferGump` (ML), `QuestReportBackGump`, `QuestRewardGump`, `QuestCancelConfirmGump`, `RaceChangeConfirmGump`.
**`StaticGump<T>` migrations**:
- `ScrollOfAbraxusGump` (Dark Tides). Its layout is a single hard-coded cliloc (1060116) with no per-instance dynamic content - safe to cache.
**Cliloc rule**: Every other quest dialog bakes per-instance cliloc IDs into its layout (quest titles, NPC names, race-specific prompts, era-conditional progress messages, escort destinations). Per the cliloc rule, baking different cliloc numbers into a cached layout would defeat `StaticGump<T>` caching - so all of these are `DynamicGump`.
**Signature changes** to support the migration:
- `QuestObjective.RenderMessage`/`RenderProgress` now take `ref DynamicGumpBuilder builder` (15 overrides updated across Collector, Solen Matriarch, Ambitious Solen Queen, Study of the Solen Hive, Terrible Hatchlings, The Summoning, Uzeraan Turmoil, Witch Apprentice, Emino's Undertaking).
- ML `BaseObjective.WriteToGump` / `BaseObjectiveInstance.WriteToGump` / `BaseReward.WriteToGump` now take `ref DynamicGumpBuilder` (KillObjective, GainSkillObjective, EscortObjective, CollectObjective, DeliverObjective, BaseReward).
**Empty-gump and `Singleton` rules**: All concrete gumps now have private constructors with static `DisplayTo` entry points that null-check the player NetState before allocation. All gumps that shouldn't stack are `Singleton => true`.
**External callers updated**: `MLQuest.SendOffer`/`OnRefuse`, `MLQuestEntry.SendProgressGump`/`SendRewardGump`/`SendReportBackGump`, `MLQuestSystem.QuestGumpRequest` and `ViewQuestsCommand`, `BoonCollector` (Darius/Nedrick), `SirHelper.OnDoubleClick` (no longer caches a single shared `InfoNPCGump` instance - `DisplayTo` constructs one per click and the gump's `Singleton => true` handles deduplication), `RaceChangeDeed.OnDoubleClick`, `PaintedImage.OnDoubleClick`, `ScrollOfAbraxus.OnDoubleClick`, `Impresario.OnTalk`, and `PlayerMobile`'s `BaseQuestGump` alias is now `BaseMLQuestGump`.
**Concrete subclasses found beyond the listed entry points**: `SheetMusicOfferGump` (in Impresario.cs), `PaintedImageGump` (was `PaintedImage.InternalGump`), `QuestObjectivesGump`, `QuestConversationsGump`, `QuestLogUpdatedGump`, `QuestItemInfoGump` (the Core base has these embedded across `QuestSystem.cs`/`QuestObjective.cs`/`QuestConversation.cs`/`QuestItemInfo.cs`).
**Code-standards cleanup**: Renamed legacy `m_X` private fields to `_x` in rewritten files; braces on all control flow.
## Summary
Second PR in the player-facing legacy gump migration. Converts the four Plants system gumps:
- `MainPlantGump`, `ReproductionGump`, `EmptyTheBowlGump` → `DynamicGump`. Layout varies by plant status, growth stage, health, and pollination/resource availability — cannot use cached `StaticGump<T>`.
- `SetToDecorativeGump` → `StaticGump<SetToDecorativeGump>`. Pure confirmation dialog with no per-instance variation.
All four:
- `Singleton => true` (auto-replace previous plant gump on re-open instead of stacking)
- Constructor `private`; entry is static `DisplayTo(Mobile, PlantItem)` per the empty-gump rule (CLAUDE.md §13)
- `OnResponse` self-refresh paths converted from `from.SendGump(new XGump(_plant))` to `from.SendGump(this)` — saves an allocation on every help/info button click and on every "gather resources/seeds/pollen" action
- Helper draw methods take `ref DynamicGumpBuilder builder` instead of mutating instance state
- Renamed legacy `m_Plant` to `_plant` per CLAUDE.md §12
Updated external callers to use the new entry points:
- `PlantItem.OnDoubleClick` → `MainPlantGump.DisplayTo(from, this)`
- `PlantPourTarget.OnTargetFinish` → `MainPlantGump.DisplayTo(from, m_Plant)` (also drops the now-redundant legacy `singleton: true` flag — `Singleton` property handles it)
- `PollinateTarget.OnTargetFinish` → `ReproductionGump.DisplayTo(from, m_Plant)`
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