ModernUO/Projects/UOContent/Engines/CannedEvil/ChampionTitleSystem.cs
Kamron Batman cce035f1c3
fix: Removes unnecessary dictionary removal guards (#2565)
## 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.
2026-08-08 11:50:01 -07:00

179 lines
4.7 KiB
C#

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using ModernUO.CodeGeneratedEvents;
using Server.Collections;
using Server.Mobiles;
namespace Server.Engines.CannedEvil;
public class ChampionTitleSystem : GenericPersistence
{
private static ChampionTitleSystem _championTitlePersistence;
// All of the players with murders
private static readonly Dictionary<PlayerMobile, ChampionTitleContext> _championTitleContexts = new();
private static readonly Timer _championTitleTimer = new ChampionTitleTimer();
public static void Configure()
{
_championTitlePersistence = new ChampionTitleSystem();
}
public static void Initialize()
{
_championTitleTimer.Start();
}
[OnEvent(nameof(PlayerMobile.PlayerDeletedEvent))]
public static void OnPlayerDeleted(Mobile m)
{
if (m is PlayerMobile pm)
{
_championTitleContexts.Remove(pm);
}
}
public ChampionTitleSystem() : base("ChampionTitles", 10)
{
}
public override void Deserialize(IGenericReader reader)
{
var version = reader.ReadEncodedInt();
var count = reader.ReadEncodedInt();
for (var i = 0; i < count; ++i)
{
var context = new ChampionTitleContext(reader.ReadEntity<PlayerMobile>());
context.Deserialize(reader);
_championTitleContexts.Add(context.Player, context);
}
}
public override void Serialize(IGenericWriter writer)
{
writer.WriteEncodedInt(0); // version
writer.WriteEncodedInt(_championTitleContexts.Count);
foreach (var (m, context) in _championTitleContexts)
{
writer.Write(m);
context.Serialize(writer);
}
}
public static bool GetChampionTitleContext(PlayerMobile player, out ChampionTitleContext context)
{
if (player != null && _championTitleContexts.TryGetValue(player, out context))
{
return true;
}
context = null;
return false;
}
public static ChampionTitleContext GetOrCreateChampionTitleContext(PlayerMobile player)
{
ref var context = ref CollectionsMarshal.GetValueRefOrAddDefault(_championTitleContexts, player, out var exists);
if (!exists)
{
context = new ChampionTitleContext(player);
}
return context;
}
// Called when killing a harrower. Will give a minimum of 1 point.
public static void AwardHarrowerTitle(PlayerMobile pm)
{
var context = GetOrCreateChampionTitleContext(pm);
var count = 1;
for (var i = 0; i < ChampionSpawnInfo.Table.Length; i++)
{
var title = context.GetTitle(ChampionSpawnInfo.Table[i].Type);
if (title?.Value > 900)
{
count++;
}
}
context.Harrower = Math.Max(count, context.Harrower); // Harrower titles never decay.
}
public static int GetChampionTitleLabel(PlayerMobile player)
{
if (!GetChampionTitleContext(player, out var context))
{
return 0;
}
if (context.Harrower > 0)
{
return 1113082 + Math.Min(context.Harrower, 10);
}
var highestValue = 0;
var highestType = 0;
for (var i = 0; i < ChampionSpawnInfo.Table.Length; i++)
{
var t = context.GetTitle(ChampionSpawnInfo.Table[i].Type);
if (t == null)
{
continue;
}
var v = t.Value;
if (v > highestValue)
{
highestValue = v;
highestType = i;
}
}
var offset = highestValue switch
{
> 800 => 3,
> 300 => highestValue / 300,
_ => 0
};
if (offset > 0)
{
var champInfo = ChampionSpawnInfo.Table[highestType];
var championLevelName = champInfo.LevelNames[Math.Min(offset, champInfo.LevelNames.Length) - 1];
return championLevelName.Number;
}
return 0;
}
private class ChampionTitleTimer : Timer
{
public ChampionTitleTimer() : base(TimeSpan.FromMinutes(5.0), TimeSpan.FromMinutes(5.0))
{
}
protected override void OnTick()
{
if (_championTitleContexts.Count == 0)
{
return;
}
foreach (var context in _championTitleContexts.Values)
{
if (!context.CheckAtrophy())
{
_championTitleContexts.Remove(context.Player);
}
}
}
}
}