JDK-7 SwingWorker deadlocks?

java, java-7, swing, swingworker

Solution

As nobody has fired off the link yet, it seems this is actually a known bug:

https://bugs.java.com/bugdatabase/view_bug?bug_id=6880336

Surprisingly there are less than 100 votes for what should be a showstopper bug for most non-trivial applications.

Problem

I have a small image processing application which does multiple things at once using SwingWorker. However, if I run the following code (oversimplified excerpt), it just hangs on JDK 7 b70 (windows) but works in 6u16. It starts a new worker within another worker and waits for its result (the real app runs multiple sub-workers and waits for all this way). Did I use some wrong patterns here (as mostly there is 3-5 workers in the swingworker-pool, which has limit of 10 I think)? ``` import javax.swing.SwingUtilities; import javax.swing.SwingWorker; public class Swing { static SwingWorker<String, Void> getWorker2() { return new SwingWorker<String, Void>() { @Override protected String doInBackground() throws Exception { return "Hello World"; } }; } static void runWorker() { SwingWorker<String, Void> worker = new SwingWorker<String, Void>() { @Override protected String doInBackground() throws Exception { SwingWorker<String, Void> sw2 = getWorker2(); sw2.execute(); return sw2.get(); } }; worker.execute(); try { System.out.println(worker.get()); } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { runWorker(); } }); } } ```

Original source