## Summary
- **Add a self-referencing `InterpolationHandler` to `ValueStringBuilder`** that writes directly into the builder's buffer — zero intermediate allocation, works with `stackalloc`-backed builders
- **Replace all `System.Text.StringBuilder` usage** across the codebase with `ValueStringBuilder`
- **Convert `ValueStringBuilder.Create()` to `stackalloc`** at 10 sites where output length is provably bounded
- **Convert manual `Dispose()` to `using var`** where possible, and hoist loop-scoped builders outside loops with `Reset()`
- **Convert verbose `Append()` chains to `Append($"...")`** interpolation for readability
- **Add comprehensive documentation** for string handling patterns
## InterpolationHandler Design
`ValueStringBuilder` is a `ref struct`, which creates challenges for C#'s interpolated string handler pattern:
- **`ref` fields to ref structs are not allowed** (CS9050)
- **`[InterpolatedStringHandlerArgument("")]` passes struct receivers by value**, not by ref
- **`ISelfInterpolatedStringHandler` requires boxing** ref structs into interface fields
**Solution: Copy-and-reconcile pattern.** The handler receives a value copy of the builder. The copy shares the same underlying `char` buffer (`Span` points to the same `stackalloc`/pooled memory), so writes go to the original buffer. `Append()` reconciles by `this = handler._builder`, updating `_length` and any buffer references changed by `Grow()`.
This is safe because:
- The game loop is single-threaded — no concurrent access between handler construction and reconciliation
- If `Grow()` occurs in the copy, the original's stale buffer isn't accessed until `Append()` replaces it
- `Dispose()` correctly returns the reconciled buffer to the pool
## Changes by Category
### ValueStringBuilder (`Projects/Server/Buffers/ValueStringBuilder.cs`)
- Added nested `InterpolationHandler` ref struct with copy-and-reconcile pattern
- Added `Append([InterpolatedStringHandlerArgument("")] scoped ref InterpolationHandler)` method
- Removed `RawInterpolatedStringHandler` overloads (new handler replaces them)
- All `AppendFormatted` overloads delegate to existing `Append` methods (no code duplication)
- Alignment support via direct private field access (nested type privilege)
### StringBuilder → ValueStringBuilder (15 files)
Replaced all `new StringBuilder()` with `ValueStringBuilder.Create()` or `stackalloc`:
- ConPVP games: KingOfTheHill, DoubleDom, CTF, BombingRun, TourneyMatch
- ConPVP infrastructure: Tournament, Participant, TourneyParticipant
- ConPVP gumps: ArenaGump, TournamentBracketGump, AcceptTeamGump, ConfirmSignupGump
- Commands: Handlers, Logging, Add
- Other: TownCrier, SpeechLogGump, TestCenter
Key patterns:
- `sb = new StringBuilder()` reassignment → `sb.Reset()`
- `sb.AppendFormat("{0:N0}", value)` → `sb.Append($"{value:N0}")`
- `sb.Append(x).Append(y)` chains → separate statements (VSB returns void)
### Create() → stackalloc (10 files)
Converted heap-allocated builders to stackalloc where output is bounded:
- ClientVersion (32), MapSelection (160), HouseRaffleStone (48)
- HolySense (96), UnholySense (96), ClientVerification (192)
- AcceptTeamGump (64), ConfirmSignupGump (64)
- BaseWeapon (160), BaseArmor (128)
### Loop optimizations (2 files)
Hoisted `ValueStringBuilder` creation outside loops with `Reset()` per iteration:
- TourneyMatch.cs: `using var` inside for loop → stackalloc before loop
- ArenaGump.cs: `Create()` + `Dispose()` per iteration → stackalloc before loop
### Append chain → interpolation (5 files)
Converted multi-line `Append()` chains to `Append($"...")`:
- BountyMessage.cs: title switch (6 cases), paragraph (15→1 Append), description lines, closing
- AcceptTeamGump, ConfirmSignupGump, TournamentBracketGump: tournament type strings
- AdminGump: comment/tag formatting in loops
### Documentation
- `dev-docs/string-handling.md`: Full reference — construction, interpolation, disposal, decision guide
- `dev-docs/claude-skills/modernuo-string-handling.md`: Claude skill with quick reference
- `CLAUDE.md`: Added rule 17 (no StringBuilder), dev-docs table entry, skills table entry
- `dev-docs/code-standards.md`: Updated memory management section
## Test Plan
- [x] `dotnet build` — 0 errors, 0 warnings
- [x] `dotnet test` — 940/940 tests pass
- [x] 28 ValueStringBuilder tests covering all reconciliation scenarios:
- Stackalloc no-grow, stackalloc with grow (→pool transition)
- Heap no-grow, heap with grow, heap double grow
- Pre-existing content with and without grow
- Sequential multiple `Append($"...")` calls
- Mixed plain + interpolated Append
- Empty interpolation, literal-only, format specifiers
- Null string holes, ISpanFormattable types
- Dispose after stackalloc→pool grow
## Summary
- Refactors the poison system to separate `Index` (globally unique ID) from `Level` (tier within a family), enabling multiple poison families (Standard, Darkglow, Parasitic) to coexist without collisions
- Implements Darkglow and Parasitic poison special effects from Mondain's Legacy: Darkglow boosts damage by 10% when attacker is ranged, Parasitic heals the attacker for damage dealt in melee range
- Fixes several bugs: `Register()` crashing on duplicate `Level` values across families, `IncreaseLevel()` crossing family boundaries, `InfectiousStrike` and `NinjaWeapons` stripping poison family via level-based lookups, and `ArchCure`/`CleansingWinds` using raw `Level + 1` instead of `IncreaseLevel()`
## Changes
**`Projects/Server/Poison.cs`** — Adds `PoisonFamily` enum and abstract `Family` property. Adds `Index` as unique identifier. Fixes `Register()` to check `Index` uniqueness (not `Level`) and validate the new poison's name (not the existing one's). Fixes `IncreaseLevel()` to use `Index + 1`, naturally respecting family boundaries via Index gaps. Replaces linear name lookup with `Dictionary`-based `PoisonsByName`.
**`Projects/UOContent/Misc/Poison.cs`** — Adds `family` parameter to `PoisonImpl`. Implements Darkglow effect (10% damage boost when `From` >1 tile, cliloc 1072850) and Parasitic effect (heals `From` for damage dealt within 1 tile, cliloc 1060203) in `PoisonTimer.OnTick()`. Renames `m_` fields to `_` convention.
**`Projects/UOContent/Misc/PoisonKinds.cs`** — New file. Moves poison registration out of `PoisonImpl` into `PoisonKinds.Configure()`. Adds `PoisonFamily` to Darkglow/Parasitic registrations. Provides extension properties (`Lesser`, `Deadly`, `LesserDarkglow`, etc.), `GetPoison(int level)` (standard-only), `GetPoisonByFamilyAndLevel()`, and `IsDarkglow`/`IsParasitic` instance helpers.
**`Projects/UOContent/Items/Weapons/Abilities/InfectiousStrike.cs`** — Family-aware poison scaling: Darkglow caps at Deadly (Poisoning/33.3), Parasitic caps at Lethal (Poisoning/25), Standard unchanged. Level bump uses `IncreaseLevel()` with family boundary check.
**`Projects/UOContent/Items/Skill Items/Ninjitsu/NinjaWeapons.cs`** — EvilOmen level bump uses `Poison.IncreaseLevel()` instead of `Poison.GetPoison(Level + 1)`.
**`Projects/UOContent/Spells/Fourth/ArchCure.cs`** and **`CleansingWindsSpell.cs`** — Replace `poison.Level + 1` with `Poison.IncreaseLevel(poison).Level` for family-safe cure chance calculation.
**`Projects/Server/Serialization/SerializationExtensions.cs`** — Serializes/deserializes `Index` instead of `Level`.
**`DarkglowPotion.cs`** / **`ParasiticPotion.cs`** — Point to actual Darkglow/Parasitic poisons instead of placeholder `Greater`.
**`PotionKeg.cs`** / **`BasePotion.cs`** — Adds Darkglow, Parasitic, Invisibility, and FlintsPungentBrew to `PotionEffect` enum and keg label support.
## Test plan
- [ ] `dotnet build` compiles cleanly (verified, 0 warnings 0 errors)
- [ ] Verify `PoisonKinds.Configure()` registers all poisons without throwing (Register bug fix)
- [ ] Standard poison behavior unchanged — PoisonField, PoisonSpell, SerpentArrow, SavageShaman, TrappableContainer all use `GetPoison(int level)` which now correctly filters to Standard family
- [ ] Darkglow: poison tick deals +10% damage when attacker is >1 tile away, sends "Darkglow poison increases your damage!" message
- [ ] Parasitic: poison tick heals attacker for damage dealt when within 1 tile, sends heal message
- [ ] InfectiousStrike preserves poison family and respects family-specific skill scaling
- [ ] EvilOmen + NinjaWeapons level bump stays within poison family
- [ ] ArchCure/CleansingWinds cure chance calculations work correctly across all poison families
- [ ] Serialization round-trips correctly using Index
## Summary
- Adds `Mobile.Murderer` virtual property and consolidates kill-threshold checks across the codebase
- Tracks ping-pong count: how many times a player crosses the 5-kill murderer threshold (T2A/UOR/UOTD only, disabled on LBR+)
- Adds `[CommandProperty]` to view a player's ping-pong count via the admin panel
- After enough ping-pongs, player is permanently flagged as a murderer regardless of kill count
- Accounts for perma-red players with low kills in murderer status transition notifications
- Implements era-appropriate "I must consider my sins" speech responses:
- **T2A**: contextual cliloc flavor text (502122–502126)
- **UOR–AOS**: raw short/long-term murder counts + ping-pong count if applicable
- **SE+**: localized stats message (1114370)
- Refactors kill-report logic out of `Keywords.cs` into `PlayerMurderSystem.ReportKillsToSelf`
## Testing
- [x] Thoroughly tested and self reviewed
- [x] Test T2A "I must consider my sins" behaviour over all scenarios.
- [x] Test UOR "I must consider my sins" behaviour over all scenarios.
- [x] Test that LBR does not have ping pongs enabled (I must consider my sins)
- [x] Test serialization cross over from v0 -> v1 increments 1 ping pong if player is already red.
## Notes
* Manually setting kills to 5 does not trigger a ping pong, it must go through the actual murder system. This includes if the kills were manually set to 5 and then migrated (as manually setting kills to 5 never adds the player into the murder system - it only happens via ReportMurderer). This is arguably a bug in the existing system, but one that currently only ever happens via staff interaction.
* Thieves guild SuspendOnMurder specifically checks for kills > 0. This means a person with 0 shorts but 5 ping pongs (flagged as murderer) can steal. This may be accurate, as according to a forum post this is how it works on UOSA which is the T2A gold standard.
* This doesn't implement Pre-T2A behaviour which should be that "I must consider my sins" does nothing at all. The reason I didn't implement it for Pre-T2A is then it 100% have to sit behind a feature flag. I don't mind adding it as a feature flag, just let me know.
## Summary
- Adds `public virtual bool Murderer => Kills >= 5` property to `Mobile`, replacing ~30 scattered `Kills >= 5` / `Kills < 5` magic-number checks across the codebase
- `BaseCreature` overrides `Murderer` to also return `true` when `AlwaysMurderer` is set
- Updates `Corpse` serialization to v15, storing `_murderer` as a `bool` field (migrated from `int Kills >= 5` in earlier versions)
> [!IMPORTANT]
> **Breaking Changes**
> - DecodePacket and EncodePacket delegates replaced with IClientEncryption interface
> - NetState.Connection (Socket) replaced with internal RingSocket management
> - NetState.RecvPipe and NetState.SendPipe removed (buffers managed internally)
## Summary
Upgrades the networking stack from PollGroup-based I/O to io_uring, significantly improving I/O performance on Linux.
This also adds native client encryption support for encrypted UO clients.
## Major Changes
io_uring Networking Architecture
- Replaced PollGroup with IORingGroup for async socket I/O operations
- Removed Pipe.cs (mirrored ring buffer) and TcpServer.cs in favor of RingSocketManager
- Added NetState.Network.cs - centralized network infrastructure handling accept, recv, send, and disconnect
completions
- Added SocketHelper.cs - platform-specific socket utilities for raw socket handle operations (getpeername,
getsockname)
- Buffer management now handled by RingSocketManager with configurable slab allocation
### Client Encryption Support
- Added full encryption stack in Network/Encryption/:
- EncryptionConfig.cs - configurable encryption modes (None, Unencrypted, Encrypted, Both)
- EncryptionManager.cs - encryption detection and initialization for login/game packets
- LoginEncryption.cs - handles login packet encryption with version-derived keys
- GameEncryption.cs - handles game server encryption using Twofish
- TwofishEngine.cs - optimized Twofish block cipher implementation
- LoginKeys.cs - encryption key table for client versions
- IClientEncryption.cs - interface for client encryption implementations
### NetState Improvements
- Replaced Socket Connection with RingSocket _socket for managed socket lifecycle
- Changed from GCHandle polling to event-based completion processing
- Disconnect handling now properly waits for pending sends to flush
- Simplified connecting socket management using lazy queue removal
### Configuration
- New settings: network.encryptionMode and network.encryptionDebug
- Encryption mode flags: Unencrypted, Encrypted, or Both
### Dependencies
- Replaced PollGroup NuGet package with IORingGroup
- Linux requires liburing-dev / liburing-devel package
### Test plan
- Verify server starts and accepts connections on Linux with io_uring
- Verify server starts and accepts connections on Windows (fallback to IOCP)
- Test unencrypted client connections (ClassicUO with encryption disabled)
- Test encrypted client connections if available
- Verify graceful disconnect flushes pending data
- Confirm CI builds pass on all target platforms
> [!IMPORTANT]
> **Developer Note**
> THIS IS A BREAKING CHANGE TO THE NEW API GUMP.
> Please give us feedback in [discord ](https://muo.gg/discord) if you have issues, need help, or have ideas for a better API change!
### Summary
* Adds support for size/style to dynamic/static builder.
* Drastically simplifies the dynamic/static builder api for AddHtml.
* Cleans up some legacy gump files.
### Summary
- Puts back `EventSink.SocketConnect`.
- Reverts networking change to push the networking to a separate thread.
- Reverts changes to the firewall by removing the firewall queue.
- Fixes listeners not shutting down with the server.
- Fixes race condition causing connections to get stuck even after they are disposed.
> [!NOTE]
> **Developer Note**
> Networking has been reverted back to using the main thread instead of a background thread. This alleviated complexity and the requirement for concurrent queues all over the place.
### Summary
- Moves `CharacterCreated` event to UOContent using code generated event _CharacterCreatedEvent_.
- Moves `TargetByResourceMacro` event to UOContent using code generated event _TargetByResourceMacro_.
- Moves `GameLogin` event to UOContent using code generated event _GameLoginEvent_.
- Moves `ServerList` event to UOContent using code generated event _ServerListEvent_.
- Streamlines ProfessionInfo
> [!IMPORTANT]
> **Developer Note**
> Custom scripts that use any of these event sinks will need to be updated to use the new code generated events.
### Summary
- Adds [Code Generated Events](https://github.com/modernuo/CodeGeneratedEvents)
- Removes EventSink.PlayerDeath
- Adds `PlayerDeathEvent` and `CreatureDeathEvent` using code generated events
> [!Important]
> **Developer Note**
> Use `[OnEvent(nameof(PlayerMobile.PlayerDeathEvent))]` instead of `EventSink.PlayerDeath` delegate
> Check this commit for examples of how to use this.
### Summary
Updates the serialization strategy to use `MemoryMappedFile` instead of thick buffers. This has the benefit of being on-par with the current implementation (based on hardware/OS), however won't incur the double-memory issue.
> [!Important]
> **Developer Note**
> The `BinaryFileWriter` and `BinaryFileReader` has been removed in favor of `MemoryMapFileWriter` and `UnmanagedDataReader`
### Summary
- Generalizes the On/Off toggle items concept
- Updates the OnOffGump so it is static
- Standardizes OnOff items so they can be used by staff
### Notes
Decided to not fix#1417 because it is not clear that the clilocs or errors are for that purpose. Can't test this on OSI anyways.
### Summary
- Removes new player "Haven Only" starting city.
- Fixed New/Old haven placement.
- Removed force-profession starting location for SA+.
- Added Royal City for SA+
- Removed Occlo for Pre-AOS.
> [!Note]
> **Developer Note**
> Now developers will only need to build/run the Application project instead of everything.
> When adding new projects, make sure to:
> 1. Add a reference to that project in the Application project.
> 2. Add the dll file to the Distribution/Data/assemblies.json file
### Summary
- Adds an application project
- Consolidates process restarts to use `Core.Kill(true)`
- Removes some old messaging, for example processor optimization
- Fixes missing build cleanup
> [!Warning]
> **Developer Warning**
> The `PacketThrottle` callback return value is now reversed. `true` indicates the connection is _throttled_.
### Summary
- Fixes an issue where connections get stalled forever
- Fixes an issue where the throttler is not working properly
- Removes account attack limiter
- Rewrites IP limiter
- Removes IP restrictions (they weren't used, and not practical)
- Fixes issue where IP limiter was counting before firewall was blocking.
View without whitespace:
https://github.com/modernuo/ModernUO/pull/1796/files?diff=split&w=1
### Summary
- Fixes various memory leaks related to spells
- Fixes Spell Plague
- Added ability to determine if `sdi` should take effect for Spell Damage.
- Fixes animal form timer ticking non-stop while logged out.
### Summary
* Adds contributors/sponsors to the "staff" list for holiday items.
* Unifies all of the staff lists
* Moves 2004 winter gifts to the appropriate folder
* Codegens the gift items
## Thank you!
Thank you to the RunUO/ServUO community, Owyn, Jaedan, the Outlands community, and the ModernUO contributors/community. Without all of you, this would not be possible! ❤️
