cce035f1c3
## 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.
51 lines
1.8 KiB
C#
51 lines
1.8 KiB
C#
/*************************************************************************
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* ModernUO *
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* Copyright 2019-2026 - ModernUO Development Team *
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* Email: hi@modernuo.com *
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* File: PromotedGuard.cs *
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* *
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* This program is free software: you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation, either version 3 of the License, or *
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* (at your option) any later version. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program. If not, see <http://www.gnu.org/licenses/>. *
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*************************************************************************/
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using System;
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using System.Collections.Generic;
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namespace Server.Network.Bans;
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/// <summary>Suppresses re-reporting the same IP within a TTL. Accept-path thread only.</summary>
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public sealed class PromotedGuard
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{
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private readonly Dictionary<UInt128, long> _expiry = [];
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public bool TryMark(UInt128 ip, long nowTicks, long ttlMs)
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{
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if (_expiry.TryGetValue(ip, out var exp) && exp - nowTicks > 0)
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{
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return false;
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}
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_expiry[ip] = nowTicks + ttlMs;
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return true;
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}
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public void Sweep(long nowTicks)
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{
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if (_expiry.Count == 0)
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{
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return;
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}
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foreach (var (ip, exp) in _expiry)
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{
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if (exp - nowTicks <= 0)
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{
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_expiry.Remove(ip);
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}
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}
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}
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}
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