Reusing Runnable objects

Question

Is there any way that I can run a fixed maximum amount of threads in parallel and REUSE the Runnable object as soon as one of the threads finishes? So, given N sets of running parameters for Runnable obj and only M Runnable objects (M < N) is there a way to make sure that as soon as one of the threads using a Runnable object finishes, I start a new thread using the same Runnable obj (thus a maximum of M threads running at one time) ?

Answer 1

You can implement Producer-Consumer pattern like:

    int n = 10;
    Executor executor = Executors.newFixedThreadPool(n);
    final BlockingQueue<Object> tasks = new ArrayBlockingQueue(1024);
    for (int i = 0; i < n; i++) {
        executor.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    while (!Thread.currentThread().isInterrupted()) {
                        Object task = tasks.take();
                        // process task
                    }
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
            }
        });
    }
    tasks.put(new Object());