Minecraft crash when shooting

[Toma™]

My minecraft does "randomly" crash when I start shooting with one weapon with small firerate, however this happens quite randomly and sometimes it's working fine for a long time and then suddenly crash. 

So there's some of the code:

BulletEntity

GunCode

Shooting code for Single firemode

Shooting code for Automatic firemode

 

Entity is registered in my main class under FMLInit event using the registerModEntityMethod (I also tried to play a bit with the tracking range and update frequency since the crash was saying something about it)

Crash report:

Spoiler

---- Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 11/15/18 1:51 PM
Description: Exception in server tick loop

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(Unknown Source)
	at java.util.HashMap$KeyIterator.next(Unknown Source)
	at net.minecraft.entity.EntityTracker.tick(EntityTracker.java:295)
	at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:854)
	at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:743)
	at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:192)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:592)
	at java.lang.Thread.run(Unknown Source)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- System Details --
Details:
	Minecraft Version: 1.12.2
	Operating System: Windows 10 (amd64) version 10.0
	Java Version: 1.8.0_172, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 780420984 bytes (744 MB) / 1038876672 bytes (990 MB) up to 1038876672 bytes (990 MB)
	JVM Flags: 3 total; -Xincgc -Xmx1024M -Xms1024M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	FML: MCP 9.42 Powered by Forge 14.23.5.2768 5 mods loaded, 5 mods active
	States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored

	| State     | ID        | Version      | Source                           | Signature |
	|:--------- |:--------- |:------------ |:-------------------------------- |:--------- |
	| UCHIJAAAA | minecraft | 1.12.2       | minecraft.jar                    | None      |
	| UCHIJAAAA | mcp       | 9.42         | minecraft.jar                    | None      |
	| UCHIJAAAA | FML       | 8.0.99.99    | forgeSrc-1.12.2-14.23.5.2768.jar | None      |
	| UCHIJAAAA | forge     | 14.23.5.2768 | forgeSrc-1.12.2-14.23.5.2768.jar | None      |
	| UCHIJAAAA | pubgmc    | 2.2.2        | bin                              | None      |

	Loaded coremods (and transformers): 
	GL info: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [EntityPlayerMP['Player789'/137, l='New World', x=250.34, y=7.66, z=-292.53]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Definitely; Client brand changed to 'fml,forge'

 

I hope I didn't mess some basic stuff again somewhere 

[Cadiboo]

Where’s your packet? I think you might be calling code from one thread (the packet handler thread) that modified stuff in another thread (the Minecraft thread) causing a concurrent modification exception

[Toma™]

The packet for shooting:

https://github.com/Toma1O6/PUBGMC-2.0/blob/master/java/com/toma/pubgmc/common/network/server/PacketShoot.java

[Toma™]

21 hours ago, diesieben07 said:

Read the warning in the documentation.

Okay I have reworked it a bit (based on the forge example). Is it good now?

The code:

Spoiler

package com.toma.pubgmc.common.network.server;

import com.toma.pubgmc.common.items.guns.GunBase;

import io.netty.buffer.ByteBuf;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.ItemStack;
import net.minecraft.server.MinecraftServer;
import net.minecraft.util.CooldownTracker;
import net.minecraft.world.World;
import net.minecraftforge.fml.common.FMLCommonHandler;
import net.minecraftforge.fml.common.network.simpleimpl.IMessage;
import net.minecraftforge.fml.common.network.simpleimpl.IMessageHandler;
import net.minecraftforge.fml.common.network.simpleimpl.MessageContext;

public class PacketShoot implements IMessage, IMessageHandler<PacketShoot, IMessage>
{
	@Override
	public void toBytes(ByteBuf buf) {
		// TODO Auto-generated method stub
		
	}
	
	@Override
	public void fromBytes(ByteBuf buf) {
		// TODO Auto-generated method stub
		
	}
	
	@Override
	public IMessage onMessage(PacketShoot message, MessageContext ctx)
	{
		World world = ctx.getServerHandler().player.world;
		EntityPlayer player = ctx.getServerHandler().player;
		ItemStack stack = player.getHeldItemMainhand();
		if(stack.getItem() instanceof GunBase)
		{
			GunBase gun = (GunBase)stack.getItem();
			CooldownTracker tracker = player.getCooldownTracker();
			
			if(stack.getItemDamage() < stack.getMaxDamage())
			{
				MinecraftServer server = FMLCommonHandler.instance().getMinecraftServerInstance();
				
				server.addScheduledTask(() ->
				{	
					if(!tracker.hasCooldown(gun))
					{
						gun.shoot(world, player, stack);
						tracker.setCooldown(gun, gun.getFireRate());
					}
				});
			}
		}
		return null;
	}
}

 

It seems to be working, but I'm not sure, but thank you both for your help

Edited November 16, 2018 by Toma™

[Toma™]

So now, if I understand it correctly, I need to move everything into the scheduled task.