## 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.
* Fixes pooled timer leaking
* Fixes `[dumptimers` command so it outputs properly, adds spacing, and stacktraces
* Adds `[Tidy]` for serializing Lists. This will remove deleted entities during world save before serializing the list.
* Adds helpers for managing Lists/Sets/Dictionaries
### New API
```cs
// Creates the list if it is null, then adds
Utility.Add(ref list, value);
Utility.Add(ref set, value);
Utility.Add(ref dict, key, value);
// Nulls the variable if the count is zero
Utility.Remove(ref list, value);
Utility.Remove(ref set, value);
Utility.Remove(ref dict, key);
// Marks entity as dirty in addition to doing the action
entity.Add(list, value);
// Marks entity as dirty, and will create list if it doesn't exist
entity.Add(ref list, value);
// Marks entity as dirty in addition to doing the action
entity.Remove(list, value);
// Marks entity as dirty, and will null the list count is zero
entity.Remove(ref list, value);
```
### Updates to [dumptimers
<img width="825" alt="Screen Shot 2021-08-14 at 2 55 10 AM" src="https://user-images.githubusercontent.com/3953314/129442449-ccf7fe14-29d6-4f3f-9366-c8eb7b9828a7.png">
### Changes/Fixes:
* Adds timer pooling.
* Allows pool to be configurable in ModernUO.json
* Pool replenishes itself asynchronously if depleted.
* Fixes an issue with barkeeps and town criers
* Fixes an issue with incognito buff icons not being removed
* Fixes an issue with polymorph name mod not being removed
* Fixes several places where timers go on forever even after an object is deleted, keeping a reference (memory leak)
* Eliminates the timer for MiningCart altogether.
* Deletes `AcidSlime` since it is a duplicate of `PoolOfAcid`
* Fixes HonorableExecution and standardizes the code for other Bushido moves.
## Changes to the Timer API:
```cs
public class Timer
{
// Creates a timer that will be returned to the pool once execution stops.
public static void StartTimer(Action callback);
public static void StartTimer(TimeSpan delay, Action callback);
public static void StartTimer(TimeSpan delay, TimeSpan interval, Action callback);
public static void StartTimer(TimeSpan interval, int count, Action callback);
public static void StartTimer(TimeSpan delay, TimeSpan interval, int count, Action callback);
// Creates a timer and returns a token for more control. Requires manual cancellation in order for the timer to be returned to the pool.
// If the token is dereferenced, the timer will be dereferenced too. While not returning a timer to the pool is not considered hazardous, it does defeat the purpose of pooled timers.
public static void StartTimer(Action callback, out TimerExecutionToken token);
public static void StartTimer(TimeSpan delay, Action callback, out TimerExecutionToken token);
public static void StartTimer(TimeSpan delay, TimeSpan interval, Action callback, out TimerExecutionToken token);
public static void StartTimer(TimeSpan interval, int count, Action callback, out TimerExecutionToken token);
public static void StartTimer(TimeSpan delay, TimeSpan interval, int count, Action callback, out TimerExecutionToken token);
// If you aren't sure how to use the API above, or you don't care about performance, then you can use the old RunUO Timer.DelayCall
public static DelayCallTimer DelayCall(Action callback);
public static DelayCallTimer DelayCall(TimeSpan delay, Action callback);
public static DelayCallTimer DelayCall(TimeSpan delay, TimeSpan interval, Action callback);
public static DelayCallTimer DelayCall(TimeSpan interval, int count, Action callback);
public static DelayCallTimer DelayCall(TimeSpan delay, TimeSpan interval, int count, Action callback);
}
public struct TimerExecutionToken
{
public bool Running { get; }
public int Index { get; }
public int RemainingCount { get; }
public DateTime Next { get; }
}
```
## When to use `TimerExecutionToken`?
Use tokens when you want to gain the performance benefit of using a pooled timer, but you need one of the following:
* Access to the next time the timer will tick:`token.Next`
* Access to which interval, how many intervals there are, or how many are remaining: `token.Index`, `token.Count`, and `token.RemainingCount`
* Stop a timer manually.
* Determine if the timer is running: `timer.Running`
* See notes below about requirements for using tokens!
## Notes about using the TimerExecutionToken:
When you opt-in to receive a token, you must call `Cancel()` to return the timer. This can be done inside of the callback, or outside of the callback at any time.
If this is not called and your timer is an infinite interval, then you will create a potential memory leak, or null pointer exception in your callback.
If the timer ends and is stopped, but cancel is not called, then the timer will never return to the pool and stay referenced until the token is deleted or cancel is called. (Memory leak)
## Is this thread safe?
No. The ModernUO timer system is not thread safe at all. If you require a thread safe timer system, contact me and I'll help adapt this system. Keep in mind that there is a massive performance hit to make this thread safe when there are literally no use cases for it.
If you need to synchronize execution, meaning you want to execute code from another thread on the core thread. Let's say you have a discord bot that is pushing commands to the game server. Then use `EventLoopContext.Post(SendOrPostCallback callback, object state);`.
- [X] Caches DateTime.NowUtc on the game loop (not other threads)
- [X] Replaces all locations where it makes sense
- [X] Adds Min/Max for `IComparable` (TimeSpan, DateTimes, etc)
Closes#261
- [X] Fixes an issue where a buffer smaller than 8 bytes would not double with enough space in some cases.
- [X] Fixes an issue with dupe copying the savebuffer reference (ugh).
- [X] Streamlines the IGenericWriter API to use better generics.
- [X] Streamlines the IGenericReader API to use better generics.
- [X] Forces `tidying` of a List/HashSet to be done externally since Writers/Readers should not have side effects.
- [X] Fixes an issue where Tidying a list didn't TrimExcess, causing memory leaks.
- [X] Reverted the meaning of `World.Running` to specifically refer to any world state post world loading.
- NOTE: Do not use this if you want to block on world saves. Instead use checks against `WorldState.Saving` states.
- [X] Fixes an issue with serializing negative DateTime deltas.
- [X] Fixes a potential issue with serializing non-UTC DateTime.
Bumps release version
