Thread pool that binds tasks for a given ID to the same thread

Question

Are there any implementations of a thread pool (in Java) that ensures all tasks for the same logical ID are executed on the same thread?

The logic I\'m after is if t

Answer 1

I have to implement a similar solution and the suggestion of creating an array of executor services by h22 seems the best approach to me with one caveat that I will be taking the modulus % of the ID (either the raw ID assuming it is long/int or the hash code) relative to some desired max size and using that result as the new ID so that way I can have a balance between ending up with way too many executor service objects while still getting a good amount of concurrency in the processing.

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ExecutorServiceRouter {

    private List services;
    private int size;

    public ExecutorServiceRouter(int size) {
        services = new ArrayList(size);
        this.size = size;
        for (int i = 0; i < size; i++) {
            services.add(Executors.newSingleThreadExecutor());
        }
    }

    public void route(long id, Runnable r) {
        services.get((int) (id % size)).execute(r);
    }

    public void shutdown() {
        for (ExecutorService service : services) {
            service.shutdown();
        }
    }

}