I'm using a ThreadPoolExecutor to run tasks. The backend is a SynchronousQueue, so if the executor is already perfoming a task, it throws the RejectedExecutionException. Here's a simple test case:

public class ExecutorTest {

  final static Worker worker = new Worker();

  public static void main(String[] args) {
    ThreadPoolExecutor executor = new ThreadPoolExecutor(1, 1, 0L, TimeUnit.MILLISECONDS, new SynchronousQueue<Runnable>());

    while (true) {
        try {                
            executor.execute(worker);                
        }catch (RejectedExecutionException e) {                
        }
    }        
  }

  static class Worker implements Runnable {

    private int i = 0;
    private long start = System.currentTimeMillis();

    @Override
    public void run() {
        try {
            Thread.sleep(1000);
            System.out.println(++i + " " + (System.currentTimeMillis() - start));
        } catch (InterruptedException ex) {                
        }
    }
  }
}

The expected bahavious is: Execute the worker and after sleeping for a second, print out i (representing how often the worker has been executed so far) and the amount of milliseconds since the worker was created. So I'm expecting:

1 1015 
2 2015
3 3016 
4 4017

This works fine for a while, but after almost on hour:

2919 2922196
2920 2942951
2921 2990407

So the amount of time between one worker execution and the next one is 20 seconds (2919->2920) and 38 seconds (2920->2921) and so forth.

java threadpoolexecutor
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