Fixes a crash, #6 #7, also fixes typo #8

sources/src/main/java/io/akarin/server/mixin/core/MixinMinecraftServer.java

@@ -174,7 +174,7 @@ public abstract class MixinMinecraftServer {
         
         for (int i = 0; i < worlds.size(); ++i) {
             WorldServer world = worlds.get(i);
-            tickConflictSync(world);
+            tickUnsafeSync(world);
             
             world.getTracker().updatePlayers();
             world.explosionDensityCache.clear(); // Paper - Optimize explosions
@@ -199,8 +199,10 @@ public abstract class MixinMinecraftServer {
         MinecraftTimings.tickablesTimer.stopTiming();
     }
     
-    public void tickConflictSync(WorldServer world) {
-        ;
+    public void tickUnsafeSync(WorldServer world) {
+        world.timings.doChunkMap.startTiming();
+        world.manager.flush();
+        world.timings.doChunkMap.stopTiming();
     }
     
 }

sources/src/main/java/io/akarin/server/mixin/core/MixinWorldServer.java

@@ -0,0 +1,16 @@
+package io.akarin.server.mixin.core;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+import net.minecraft.server.WorldServer;
+
+@Mixin(value = WorldServer.class, remap = false)
+public class MixinWorldServer {
+    @Redirect(method = "doTick", at = @At(
+            value = "INVOKE",
+            target = "net/minecraft/server/PlayerChunkMap.flush()V"
+    ))
+    public void onFlush() {} // Migrated to main thread
+}

sources/src/main/java/io/akarin/server/mixin/nsc/NonblockingServerConnection.java

@@ -17,6 +17,7 @@ import org.spongepowered.asm.mixin.Overwrite;
 import org.spongepowered.asm.mixin.Shadow;
 import com.google.common.collect.Lists;
 
+import io.akarin.api.Akari;
 import io.akarin.api.LocalAddress;
 import io.akarin.server.core.AkarinGlobalConfig;
 import io.akarin.server.core.ChannelAdapter;

sources/src/main/java/net/minecraft/server/PlayerList.java

@@ -47,6 +47,12 @@ import org.bukkit.util.Vector;
 import org.spigotmc.event.player.PlayerSpawnLocationEvent;
 // CraftBukkit end
 
+/**
+ * <b>Akarin Changes Note</b><br>
+ * <br>
+ * 1) Modify disconnect and connect messages<br>
+ * @author cakoyo
+ */
 public abstract class PlayerList {
 
     public static final File a = new File("banned-players.json");