+
+ /** Workaround for blocking Gogo shell by system shutdown. */
+ private class GogoShellKiller extends Thread {
+
+ public GogoShellKiller() {
+ super("Gogo shell killer");
+ setDaemon(true);
+ }
+
+ @Override
+ public void run() {
+ ThreadGroup rootTg = getRootThreadGroup(null);
+ Thread gogoShellThread = findGogoShellThread(rootTg);
+ if (gogoShellThread == null)
+ return;
+ while (getNonDaemonCount(rootTg) > 2) {
+ try {
+ Thread.sleep(100);
+ } catch (InterruptedException e) {
+ // silent
+ }
+ }
+ gogoShellThread = findGogoShellThread(rootTg);
+ if (gogoShellThread == null)
+ return;
+ System.exit(0);
+ }
+ }
+
+ private static ThreadGroup getRootThreadGroup(ThreadGroup tg) {
+ if (tg == null)
+ tg = Thread.currentThread().getThreadGroup();
+ if (tg.getParent() == null)
+ return tg;
+ else
+ return getRootThreadGroup(tg.getParent());
+ }
+
+ private static int getNonDaemonCount(ThreadGroup rootThreadGroup) {
+ Thread[] threads = new Thread[rootThreadGroup.activeCount()];
+ rootThreadGroup.enumerate(threads);
+ int nonDameonCount = 0;
+ for (Thread t : threads)
+ if (!t.isDaemon())
+ nonDameonCount++;
+ return nonDameonCount;
+ }
+
+ private static Thread findGogoShellThread(ThreadGroup rootThreadGroup) {
+ Thread[] threads = new Thread[rootThreadGroup.activeCount()];
+ rootThreadGroup.enumerate(threads, true);
+ for (Thread thread : threads) {
+ if (thread.getName().equals("Gogo shell"))
+ return thread;
+ }
+ return null;
+ }
+