[1.11.2] Commands that add scheduled tasks to server

[Alexiy]

Let's say I have a server command which starts a Thread

 

    @Override
    void execute(MinecraftServer server, ICommandSender sender, String[] args) throws CommandException {
        WorldServer world=sender.entityWorld as WorldServer
        if(args)
        {
            if(args.size()==1)
            {
                String action=args[0]
                ChunkPos chunkPos=new ChunkPos(sender.position)
                int chunkx=chunkPos.chunkXPos
                int chunkz=chunkPos.chunkZPos
                if(action==STOP_GENERATION)
                {
                    if(landGenerator && landGenerator.isAlive()){
                        landGenerator.interrupt()
                        sender.sendMessage(new TextComponentString('Sent stop signal'))
                    }

                }
               
            }
            else
            if(args.size()==2)
            {
                BlockPos startposition=sender.position
                String action=String.valueOf(args[0])
                if(action==START_GENERATION) {
                    int range = parseInt(args[1])

                    landGenerator = new LandGenerator(world, range, startposition,sender)
                    world.addScheduledTask(landGenerator)
                }
            }
            else if (args.size()==3)
            {
                String s=String.valueOf(args[0])
                int cx=parseInt(args[1])
                int cz=parseInt(args[2])
                
            }
        }
    }

 

This is a thread which generates world chunks (don't ask me why)

 

class LandGenerator extends Thread{


    WorldServer serverWorld
    int range
    BlockPos centerPosititon
    int x1=0,x2=0,z1=0,z2=0
    ICommandSender commander
    Runtime runtime=Runtime.getRuntime()
    LandGenerator(WorldServer worldServer, int radius,BlockPos center,ICommandSender sender)
    {
        super("Land generator")
        Chunk centerchunk=worldServer.getChunkFromBlockCoords(center)
        ChunkPos chunkPos=centerchunk.getPos()
        serverWorld=worldServer
        range=radius
        centerPosititon=center
        int x=chunkPos.chunkXPos
        int z= chunkPos.chunkZPos
        x1=x-range
        z1=z-range
        x2=x+range
        z2=z+range
        commander=sender
    }
    @Override
    void run() {

        commander.sendMessage(new TextComponentString("Started generation in $range chunk range"))
        IChunkGenerator chunkGenerator= serverWorld.getChunkProvider().chunkGenerator
        int chunkamount=0;
        ChunkPos chunkPos=new ChunkPos(centerPosititon)
        d:
        for (int xx = x1; xx < x2; xx++) {
            for (int zz = z1; zz <z2 ; zz++) {

                ChunkPos curpos=new ChunkPos(xx,zz)
                boolean generated= serverWorld.isChunkGeneratedAt(xx,zz)
                if(!generated){
                    Chunk chunk=chunkGenerator.provideChunk(xx,zz)
                    serverWorld.chunkProvider.chunkLoader.saveChunk(serverWorld,chunk)
                    generated=serverWorld.isChunkGeneratedAt(xx,zz)
                    if(generated) {
                        println("Generated chunk at $xx, $zz")
                        chunkamount++;
                        long freememory=runtime.maxMemory()-(runtime.totalMemory()-runtime.freeMemory())
                        float freeMBs=freememory/1024/1024
                        println(freeMBs+" MB")
                        if(freeMBs<300){
                            commander.sendMessage(new TextComponentString("Generation terminated due to low free memory"))
                            break d
                        }
                    }
                }
            }
        }

        commander.sendMessage(new TextComponentString("Generated $chunkamount chunks"))
    }

    @Override
    void interrupt() {
        super.interrupt()
        commander.sendMessage(new TextComponentString('Generation interrupted'))
    }
}

 

While the thread is working, I can't execute any other commands. Is there a solution to this?

[Choonster]

IThreadListener#addScheduledTask is intended to be called from a background thread (usually a Netty thread) to schedule a task to run on the main thread next tick. When called from the main thread, it executes the task immediately.

 

You're not actually starting a new thread, you're just calling the LandGenerator#run method on the main thread.

 

As diesieben07 said, you can't safely interact with the world from a separate thread.

 

Side note: You can't compare Strings with the == operator, use the Object#equals method.