java - 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'm looking for is all 12 threads start working at the same time & finish at the same time.

I have the following:

for (int i = 0; i < 12; i++ )
{
        myTask m = new Mytask(i, START);
        m.execute();
}

The myTask m will increment a progress bar from 0 - 100 in increments of 25. I'm getting outlandish behavior that the first six threads start incrementing, they finish at 100, then the last six threads start from 0 and increment, and finish.

Is there a limiting factor on the amount of Swing Worker threads one may have?

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.