Swing Worker Threads Not Concurrent

Question

It seems that when I instantiate 12 Swing Worker threads, the first six starts to complete its task, it finishes AND then the last six starts and finishes. The behavior I\'

Answer 1

The behavior I'm looking for is all 12 threads start working at the same time & finish at the same time.

A CountDownLatch is designed for this very purpose. Here's a good example using a single SwingWorker and a number of subsidiary threads controlled by the latch.

Answer 2

Your question says:

The behavior I'm looking for is all 12 threads start working at the same time & finish at the same time.

But you can't guarantee for all Swing workers threads starting concurrently and ending at same time.

Answer 3

SwingWorker class has a static ExecutorService field with MAX_WORKER_THREADS = 10. I'm not certain why you see 6 and not 10. But you cannot go over 10.

    /**
     * number of worker threads.
     */
    private static final int MAX_WORKER_THREADS = 10;

...

    executorService =
                new ThreadPoolExecutor(1, MAX_WORKER_THREADS,
                                       10L, TimeUnit.MINUTES,
                                       new LinkedBlockingQueue<Runnable>(),
                                       threadFactory);