Overview

• This project is used to fix and optimize issues caused by other mods, and it works on servers.
• The project contains two main parts: k_all_fix and k_multi_threading, with features mainly controlled by JVM parameters.
• No regular config file is provided; configuration is mainly done through startup parameters.
• Client-side usage is supported from 1.0.4.0 onward (requires JVM parameter -DKMT_Client=true).
• Under a multi-mod and single-threaded baseline environment, cause no issues is not guaranteed, but you could create an ISSUE on Github and the author will fix it quickly.
• With some mod combinations, clients may still need to install this mod even if it has no visible effect.

Features and Use Cases

Optimizations

• Optimizes performance for Upgraded Additional Trims.
• Optimizes the April Fools date-check related overhead in Atmospheric.
• Optimizes performance for Upgraded Core.
• Optimizes chicken-coop AI performance in [Let's Do] Farm & Charm.
• Optimize performance for Event Wrapper
• Optimize performance for Create：FluidLogistic
  • -DKAF-fluidlogistics.DisabledDynamicUp=true to disable updating old id, if not do so, may cause to preformance slow down.
• Optimize AE2 game computation
• Optimize performance for ItemStack.issameItemsameTags
• Optimize performance of PPMO2
• Delete useless code of Apotheosis and Create:Connected

Fixes

• Fixes performance issues related to entity counts in L_Ender's Cataclysm when used on servers with MineColonies.
• Fixes excessive invalid packet sending in [Let's Do] Farm & Charm.
• Fixes compatibility issues between Biolith and some MCreator worldgen mods (e.g., Terramity).
• Fixes compatibility issues between Gregicality Rocketry and Canary, but collision-box issues may still occur at space-station borders.
• Fixes the issue where Petrolpark's Library 1.4.2 is unusable in some Java environments; this fix can be disabled with -DKAF-DisablePetrolpark=false.
• Fixes/optimizes magnetic-field-related performance issues in Alex's Caves.
• Fixes mixin performance issues in Create: Diesel Generators.
• Fixes server crashes in older Destroy versions caused by database connection failures.

Multithreading

Introduction

• Multithreading supports includes block ticks, block entity ticks, entities, dimensions, player packet receiving (manual toggle, client-only), and player login (manual toggle), and also fixes some problematic single-threaded mods by applying multithreading.
• Multithreading is enabled by default on the server side.
• In multithreaded scenarios, thread-pool interception or limit-exceeded errors may appear, but they usually do not crash the server.
• It is recommended to manually set -DKMT-threadMax=[CPU thread count]; otherwise world generation may be frozen. If freezes still occurs after setting it, increase the value higher.
• Before 1.0.4.0, clients cannot use multithreading; from 1.0.4.0 onward, clients can enable it via -DKMT_Client=true.
• After 1.0.3.3, ParaServerChunkProvider, TaskRun, and some chunk generation code depend more heavily on C2 compilation (the JVM will enter C2 automatically after running for a while).
• In Windows Server 2022 Datacenter 21H2 20348.3091 (author's environment), rare thread scheduling anomalies may occur and causes abnormally high CPU usage; the solution is to restart the server.

Related JVM Parameters

• -DKMT-threadMax=[number]
  • Sets thread-pool thread count.
• -DKMT-callMax=[number]
  • Sets the default maximum number of threads that multithreaded tasks may use.
• -DKMT-ThreadpoolKeepAliveTime=[milliseconds]
  • Sets how long idle threads are kept before recycling.
• -DKMT_D=[any characters]
  • Disables multithreading.
• -DKMT-OpenVanillaServerChunkCache=true
  • Forces the vanilla ServerChunkCache fix path (added in 1.0.5.3).

JVM Parameter Overview (all retained)

Basic and General

• -DKAllFix_D=[any characters]
  • Disables KAllFix.
• -DKMT_Client=true
  • Enables multithreading-related features on the client side (1.0.4.0+).
• -DKAF-DisablePetrolpark=false
  • Disables the Petrolpark's Library 1.4.2 related fix.

Connection and Timeout

• -DKAF-ClientboundKeepAlivePacket_Max=[milliseconds]
  • Changes the timing requirement for ClientboundKeepAlivePacket (default 15 seconds; vanilla must be <30 seconds or the player is kicked for timeout).
• -DKAF-ServerTimeout=[seconds]
  • Sets server connection timeout.
  • May be ineffective in some cases (both parameters are needed because Forge's forge.readTimeout only covers server packet-read timeout, not client/server network threads with players).
• -Dforge.readTimeout=[seconds]
  • Forge packet-read timeout parameter (used together with the previous parameter).

Mixin / NBT / Auto Command

• -DKAF-RemoveMixin:[class name]
  • Disables a specified mixin (k_multi_threading mixins can also be disabled).
• -DKAF-NbtIoMixin_NotGZip=true
  • Adds try-catch to NBT IO for non-gzip scenarios (unsafe; requires commons-compress in the environment).
• -DKMT-ChunkGeneratorMode2Start=[true,false]
  • Automatically runs: /SetterWorldConfig world setM2 %%KMT-ChunkGeneratorMode2Start%%.

Breeding Control

• -DKAF-ChunkBreedingControlSize=[number]
  • Disables breeding when chunk entity count exceeds the given value; disabled if the parameter is missing / not a numeric array / empty.
• -DKAF-ChunkBreedingControlSizeEnable=[true,false]
  • Internal cache switch for detection results; manual setting may be overridden by the program.

Optional Features

• -DKMT-SafeUnloadChunk=true
  • Enables chunk unload in chunk-generation threads (recommended only for <1.0.4.2 when related freezes occur).
• -DIndependencePlayer=true
  • Enables asynchronous player handling (likely provides little to no optimization).
• -DFixBiolithBugMode2=true
  • Attempts to fix most Biolith compatibility issues (may introduce major bugs).
• -DKAF-gtceu.MedicalConditionTrackerMixin=true
  • Disables radiation in GTM.
• -DKAF-RemoveClientboundKeepAlivePacket=true
  • Disables vanilla ClientboundKeepAlivePacket (ping can no longer be calculated).
• -DKAF-RemoveFlyingTest=true
  • Removes flight checks.
• -DKAF-moonrise_fast_palette=true
  • Disable the fast_palette feature from Moonrise.
• -DKAF-FixTFMGDestroy=true
  • Fixes compatibility between Destroy and Create (Creative Pump cannot properly connect to Create's pipes).
• -DKAF-Fix_fabric-object-builder-api.jar=true
  • Fixes compatibility between Sinytra Connector's fabric-object-builder-api and forge-47.3.27.
• -DKAF-FixAllPacket=true
  • Fixes network packets (must be enabled on both client and server); related mods: Mekanism Explosives, Create, The Abyss II.
• -DKAF-ChunkAwareBlockCollisionSweeperFast=true
  • Use approximation algorithm to replace ChunkAwareBlockCollisionSweeper of Lithium

Login Multithreading

• -DKMT-LoginMultiThreading=true
  • Enables multithreaded login.
• -DKMT-LoginMultiThreading.ConnectionLock=true
  • Waits for async execution completion at tick end (disabling may improve performance somewhat, but lowers login stability and may crash).
• -DKMT-LoginMultiThreading.TaskSizeMax=[number]
  • Limits the number of concurrent login tasks (default 8).
• Login multithreading may cause the server to receive ServerboundMovePlayerPacket early, leading to one error log.

Packet Optimization

• -DKAF-packetOptimize=true
  • Optimizes some vanilla packets (must be enabled on both client and server).
• -DKAF-packetOptimize.AttributesReOutputTime=[milliseconds]
  • Sets forced resend interval for attribute-related data (default 2 minutes).
• -DKAF-packetOptimize.CompatibilityMode.ClientboundBlockEntityDataPacket=true
  • Uses more conservative compression for ClientboundBlockEntityDataPacket (impacts performance).
• -DKAF-packetOptimize.CompatibilityMode.ClientboundSectionBlocksUpdatePacket=true
  • Uses more conservative compression for ClientboundSectionBlocksUpdatePacket.

Others

• -DKAF-UnsafeCinderscapesFix1=true
  • Adjusts limits for the high-overhead enableAshFall function in Cinderscapes.
• -DKAF-fix.asynchronous.ClientboundCustomQueryPacket=true
  • Makes handshake asynchronous, reducing the chance of being unable to join when too many mods are installed.
• -DKAF-FixConfigAuto=true
  • Automatically changes some config options for compatibility.

Installation and Runtime Notes

• From 1.0.3.18, it can run directly (installation feature is still kept).
• Before 1.0.3.18, run the mod's installer first, or use:
  • java -jar k_multi_threading-xxx.jar -i [empty or install directory]
• Installation only generates k_multi_threading-base.jar and k_multi_threading-asm.jar.
• Some features may download dependencies (Zstd-jni 1.5.7-2); if download fails, place them manually in game_directory/lib.

Compatibility Notes

• Using -DKAF-FixConfigAuto=true can automatically disable:
  • logOffthreadEntityAdd in Cupboard.
  • world.tick_scheduler and entity_by_type in Canary / Lithium (you must manually add mixin.world.tick_scheduler=false in config/canary.properties or config/lithium.properties; otherwise these mod will override the multithread fix for ClassInstanceMultiMap).
• Cases where -DKAF-FixConfigAuto=true should not be used:
  • Possible conflict with mixin.perf.cache_upgraded_structures in ModernFix (disable via mixin.perf.cache_upgraded_structures=false in config/modernfix-mixins.properties).
  • With login multithreading enabled, ParCool (listed as Parkour on page) may require one death after player joining before working normally.
  • Ars Creo may rarely log Modifier is already applied on this attribute!, but will not crash.
  • NuclearCraft: Neoteric fission reactors may rarely calculate cooling incorrectly after server restart.

Commands

• /debug_GetterClassFile [class name]

  • Exports final runtime class data to the game directory, with filename format timestamp_save.class.

• /SetterWorldConfig [world, ClearErrorSize, RemoveRemoveErrorSize]

  • Settings from this command are not persistent.
  • ClearErrorSize: clears the recorded count of “errors that caused server crash risk”.
  • RemoveRemoveErrorSize: stops recording crash-risk counts and keeps intercepting.
  • Under world [dimension registry id], available options:
    • setM2 [true,false]: switches to another dimension implementation mode; higher priority than setMultiThreading, but may freeze the game.
    • setMultiThreading [number] (default 0): sets multithread parallel task count for this dimension; independent mode from setM2, and may also freeze the game.

Others

• Because Minecraft and many mods are fundamentally designed around single-threaded behavior, complete fixes for all issues cannot be guaranteed.

Source Code Usage

• moonrise_fast_palette uses source code from Moonrise.
• Compatibility fixes for Gregicality Rocketry and Canary use source code from Canary.