Use separate thread to dispatch OTM network packets to players

src/main/kotlin/ru/dbotthepony/mc/otm/GlobalEventHandler.kt

@@ -22,6 +22,7 @@ import ru.dbotthepony.mc.otm.core.util.IConditionalTickable
 import ru.dbotthepony.mc.otm.core.util.ITickable
 import ru.dbotthepony.mc.otm.core.util.TickList
 import ru.dbotthepony.mc.otm.graph.Abstract6Graph
+import ru.dbotthepony.mc.otm.network.MatteryNetworkChannel
 import java.util.*
 
 private val preServerTick = TickList()
@@ -151,6 +152,7 @@ fun onServerTick(event: ServerTickEvent) {
 		// чтоб не плодить кучу подписчиков, вызовем напрямую отсюда
 		Abstract6Graph.tick()
 		AbstractProfiledStorage.onServerPostTick()
+		MatteryNetworkChannel.onServerPostTick()
 	}
 }
 
@@ -270,16 +272,18 @@ fun onServerStarting(event: ServerAboutToStartEvent) {
 	SERVER_IS_LIVE = true
 	_server = event.server
 	_serverThread = Thread.currentThread()
+	MatteryNetworkChannel.onServerStarting()
 }
 
 fun onServerStopping(event: ServerStoppingEvent) {
 	clear()
 	SERVER_IS_LIVE = false
+	MatteryNetworkChannel.onServerStopping()
 }
 
 fun onServerStopped(event: ServerStoppedEvent) {
 	if (SERVER_IS_LIVE) {
-		LOGGER.fatal("ServerStoppingEvent did not fire. If server has crashed this is normal. However, if server finished it's work 'gracefully' this is a bug.")
+		LOGGER.fatal("ServerStoppingEvent did not fire. If server has crashed this is normal. However, if server finished it's work 'gracefully' this is a bug!")
 
 		clear()
 		SERVER_IS_LIVE = false
@@ -287,4 +291,5 @@ fun onServerStopped(event: ServerStoppedEvent) {
 
 	_server = null
 	_serverThread = null
+	MatteryNetworkChannel.onServerStopped()
 }

src/main/kotlin/ru/dbotthepony/mc/otm/network/MatteryNetworkChannel.kt

@@ -6,17 +6,24 @@ import net.minecraft.resources.ResourceLocation
 import net.minecraft.server.level.ServerPlayer
 import net.minecraft.world.entity.Entity
 import net.minecraft.world.entity.player.Player
+import net.minecraftforge.event.TickEvent
+import net.minecraftforge.event.TickEvent.ServerTickEvent
+import net.minecraftforge.event.server.ServerStoppedEvent
+import net.minecraftforge.event.server.ServerStoppingEvent
 import net.minecraftforge.network.NetworkDirection
 import net.minecraftforge.network.NetworkEvent
 import net.minecraftforge.network.NetworkRegistry
 import net.minecraftforge.network.PacketDistributor
 import net.minecraftforge.network.simple.SimpleChannel
+import org.apache.logging.log4j.LogManager
 import ru.dbotthepony.mc.otm.NULLABLE_MINECRAFT_SERVER
 import ru.dbotthepony.mc.otm.OverdriveThatMatters
 import java.math.BigDecimal
 import java.math.BigInteger
 import java.util.Optional
 import java.util.concurrent.CompletableFuture
+import java.util.concurrent.ConcurrentLinkedDeque
+import java.util.concurrent.locks.LockSupport
 import java.util.function.BiConsumer
 import java.util.function.Supplier
 import kotlin.reflect.KClass
@@ -30,18 +37,6 @@ var Supplier<NetworkEvent.Context>.packetHandled: Boolean
 val Supplier<NetworkEvent.Context>.sender: ServerPlayer?
 	get() = get().sender
 
-fun FriendlyByteBuf.writeDecimal(value: BigDecimal) {
-	writeInt(value.scale())
-	writeByteArray(value.unscaledValue().toByteArray())
-}
-
-fun FriendlyByteBuf.readDecimal(): BigDecimal {
-	val scale = readInt()
-	val bytes = readByteArray()
-
-	return BigDecimal(BigInteger(bytes), scale)
-}
-
 interface MatteryPacket {
 	fun write(buff: FriendlyByteBuf)
 	fun play(context: Supplier<NetworkEvent.Context>)
@@ -59,7 +54,7 @@ abstract class MatteryNetworkChannel(val version: String, val name: String) {
 
 	fun send(ply: Player, packet: Any) {
 		if (ply is ServerPlayer) {
-			channel.send(PacketDistributor.PLAYER.with { ply }, packet)
+			queue.add(Task(channel, PacketDistributor.PLAYER.with { ply }, packet))
 		}
 	}
 
@@ -68,7 +63,7 @@ abstract class MatteryNetworkChannel(val version: String, val name: String) {
 			return
 		}
 
-		channel.send(PacketDistributor.TRACKING_ENTITY.with { entity }, packet)
+		queue.add(Task(channel, PacketDistributor.TRACKING_ENTITY.with { entity }, packet))
 	}
 
 	fun sendTrackingAndSelf(entity: Entity, packet: Any) {
@@ -76,10 +71,12 @@ abstract class MatteryNetworkChannel(val version: String, val name: String) {
 			return
 		}
 
-		channel.send(PacketDistributor.TRACKING_ENTITY_AND_SELF.with { entity }, packet)
+		queue.add(Task(channel, PacketDistributor.TRACKING_ENTITY_AND_SELF.with { entity }, packet))
 	}
 
-	fun send(distributor: PacketDistributor.PacketTarget, packet: Any) = channel.send(distributor, packet)
+	fun send(distributor: PacketDistributor.PacketTarget, packet: Any) {
+		queue.add(Task(channel, distributor, packet))
+	}
 
 	private var nextNetworkPacketID = 0
 
@@ -113,4 +110,52 @@ abstract class MatteryNetworkChannel(val version: String, val name: String) {
 	) {
 		add(packetClass.java, MatteryPacket::write, reader, MatteryPacket::play, direction)
 	}
+
+	private data class Task(val channel: SimpleChannel, val target: PacketDistributor.PacketTarget, val packet: Any)
+
+	companion object {
+		private val logger = LogManager.getLogger()
+		private var thread: Thread? = null
+
+		private val queue = ConcurrentLinkedDeque<Task>()
+
+		@Volatile
+		private var interrupt = false
+
+		private fun run() {
+			while (!interrupt) {
+				val task = queue.pollFirst()
+
+				if (task == null) {
+					LockSupport.park()
+				} else {
+					try {
+						task.channel.send(task.target, task.packet)
+					} catch(err: Throwable) {
+						logger.error("Error executing network dispatcher task", err)
+					}
+				}
+			}
+
+			logger.debug("Overdrive That Matters Packet Dispatcher thread exited gracefully")
+		}
+
+		internal fun onServerPostTick() {
+			LockSupport.unpark(thread)
+		}
+
+		internal fun onServerStarting() {
+			interrupt = false
+			check(thread == null) { "Already having network dispatcher thread, ServerStartingEvent was fired twice!" }
+			thread = Thread(this::run, "Overdrive That Matters Network Dispatcher").also { it.start() }
+		}
+
+		internal fun onServerStopping() {
+			interrupt = true
+		}
+
+		internal fun onServerStopped() {
+			interrupt = true
+		}
+	}
 }