I have a (server-side) mod which is accessing a large number of chunks when it activates.  Once accessed, these chunks do not need to remain in the cache as they are not likely to be accessed again for a long time.

 

The problem is that the Java heap memory runs out.  This is because the IChunkProvider.getLoadedChunkCount() shows me that I have many thousands of chunks still in the cache, exhausting the available memory.

 

My question is, how can I kick these out of the cache?

 

I've tried all of these:

 

    world.getChunkProvider().saveChunks(true,null);

    world.getSaveHandler().flush();     

    world.getChunkProvider().unloadQueuedChunks();

    world.getWorldChunkManager().cleanupCache(); 

    (new Chunk(world, x, y)).setChunkLoaded(false);

 

However none of them seem to affect the cache size, which goes relentlessly upwards until a malloc error ends its life.

 

What is the correct way to flag these cached chunks for unloading?

 

TIA

ChunkProviderServer.unloadAllChunks.. This appears to unload all the chunks... I wonder how it does that..

    public void unloadAllChunks()
    {
        Iterator iterator = this.loadedChunks.iterator();

        while (iterator.hasNext())
        {
            Chunk chunk = (Chunk)iterator.next();
            this.dropChunk(chunk.xPosition, chunk.zPosition);
        }
    }

It loops through all loaded chunks.. can calls dropChunk....

But I only want to unload one chunk... I wonder what should I do?

Thanks for this; I'd found IChunkProvider but not ChunkProvderServer.  Obviously now I can call dropChunk() to get rid on the individual chunks (for some reason, dropChunk does not appear to exist in IChunkProvider).

 

I assume that the instance of ChunkProviderServer to use this one --

ChunkProviderServer cps;
cps = MinecraftServer.getServer().worldServers[0].theChunkProviderServer;
cps.saveChunks(true,null); // make sure we have no pending updates
cps.dropChunk(x,z);

 

... and indeed, the getLoadedChunkCount() from both the IChunkProvider and the ChunkProviderServer now never goes above approx 700, and the memory death is averted. 

 

Thanks for the help

 

ChunkProviderServer cps;
cps = MinecraftServer.getServer().worldServers[0].theChunkProviderServer;

 

So, you only need that for the overworld then?