Jump to content

[SOLVED][1.8] Strange Netty crashes.


Tyron

Recommended Posts

I'm getting some really strange crashes when I testplay my mod via Open-To-Lan.

I'm using forge build 1412

 

The client connecting gets this crash after 0-3 seconds after joining:

09:31:18] [Netty Client IO #2/ERROR] [FML/]: SimpleChannelHandlerWrapper exception
io.netty.handler.codec.DecoderException: java.lang.NullPointerException: Undefined message for discriminator 10 in channel vintagecraft

 

- However my mod using the vintagecraft channel registers only Message with the discriminators 0,1,2,3,4,5,6,7!

 

 

On the machine where i opened to lan I get this crash:

 

Caused by: java.lang.IndexOutOfBoundsException: readerIndex(165) + length(1) exceeds writerIndex(165): UnpooledHeapByteBuf(ridx: 165, widx: 165, cap: 256)
at io.netty.buffer.AbstractByteBuf.checkReadableBytes(AbstractByteBuf.java:1161) ~[AbstractByteBuf.class:4.0.15.Final]
at io.netty.buffer.AbstractByteBuf.readByte(AbstractByteBuf.java:563) ~[AbstractByteBuf.class:4.0.15.Final]
at net.minecraft.network.PacketBuffer.readByte(SourceFile:609) ~[hd.class:?]
at net.minecraftforge.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:73) ~[FMLIndexedMessageToMessageCodec.class:?]

(full crash report)

 

I checked the forge and minecraft source code. This crash apparently happens when Forge tries to read the package discriminator.

 

My best guess which Packet is causing the crash is MechanicalNetworkNBTPacket.java

 

Registered via: packetPipeline.registerMessage(MechanicalNetworkNBTPacket.ClientHandler.class, MechanicalNetworkNBTPacket.class, 4, Side.CLIENT);

 

The packet send command:

@SubscribeEvent
public void onServerTick(TickEvent.WorldTickEvent event) {
   [....other code....]

if (event.world.getWorldTime() % 40 == 0) {
		NBTTagCompound nbt = new NBTTagCompound();
		writeToNBT(nbt);
		VintageCraft.packetPipeline.sendToDimension(
			new MechanicalNetworkNBTPacket(nbt, networkId), 
			event.world.provider.getDimensionId()
		);
	}
}

 

What am I doing wrong here?

Link to comment
Share on other sites

Hi

 

I've had this problem twice before-

one time, my toBytes() packet code was overwriting the discriminator.  (The buffer passed to toBytes() has the discriminator at position 0 and you're supposed to append to it.) 

 

another time, it was caused by a thread synchronisation bug (race condition) when sending to dimension or allNearbyPlayers.

https://github.com/MinecraftForge/MinecraftForge/issues/1908

 

Try changing this line

VintageCraft.packetPipeline.sendToDimension(

            new MechanicalNetworkNBTPacket(nbt, networkId),

            event.world.provider.getDimensionId()

        );

i.e. copy the code out of the forge sendToDimension to find the list of players and send them all a message one by one

 

for example

//    StartupCommon.simpleNetworkWrapper.sendToDimension(msg, sendingPlayer.dimension);  // DO NOT USE sendToDimension, it is buggy
//    as of build 1419 - see https://github.com/MinecraftForge/MinecraftForge/issues/1908

    int dimension = sendingPlayer.dimension;
    MinecraftServer minecraftServer = sendingPlayer.mcServer;
    for (EntityPlayerMP player : (List<EntityPlayerMP>)minecraftServer.getConfigurationManager().playerEntityList) {
      TargetEffectMessageToClient msg = new TargetEffectMessageToClient(message.getTargetCoordinates());   // must generate a fresh message for every player!
      if (dimension == player.dimension) {
        StartupCommon.simpleNetworkWrapper.sendTo(msg, player);
      }
    }

 

-TGG

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Announcements



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.