The threadpool executer in ThreadUtil prevents the JVM from exiting.

[odinsbane]

When tasks are called that use the ThreadUtil.threadPoolExecutor the executor prevents the jvm from exiting after the task/program has finished.

For example:

import ij.process.ImageProcessor;
import ij.process.ShortProcessor;
import ij.util.ThreadUtil;

public class HoldUp {

    public static void main(String[] args){
        ImageProcessor proc = new ShortProcessor(256, 256);
        proc.blurGaussian( 2.0 );
        //ThreadUtil.threadPoolExecutor.shutdown();
    }
}

That program will not finish unless the last line is uncommented. Some suggestions.

• Use ForkJoinPool.commonPool() it will have similar behavior but you dont have to shut it down.
• Use ExecutorService.invokeAll