LightPsi parser in standalone project blocks programm completion

Hi,

When I run my simple example the program is still running. How can I close it programmatically? Is there something like .close() or .disconnect() I am not aware of? Or is System.exit(0); the way to go (which would be bad in my case)?

import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiFile;
import com.intellij.psi.util.PsiTreeUtil;

import java.io.File;
import java.io.IOException;
import java.util.Collection;

public static void main(String[] args){
 try {
 File file = new File(CountKeywords.class.getResource("/example.x").getFile());

 PsiFile psiFile = XStandaloneParser.parse(file);

 PsiElement root = psiFile.getNode().getPsi();

 Collection<PsiElement> keywords = PsiTreeUtil.findChildrenOfType(root, XKeyword.class);

 System.out.println("There are " + keywords.size() + " keywords.");

 }catch (IOException ex){
 ex.printStackTrace();
 }
}

import com.intellij.psi.PsiFile;
import org.intellij.grammar.LightPsi;

import java.io.File;
import java.io.IOException;

public class XStandaloneParser {
public static PsiFile parse(File file) throws IOException {

 try {
 return LightPsi.parseFile(file, new XParserDefinition());
 } catch (ClassNotFoundException e) {
 e.printStackTrace();
 } catch (InstantiationException e) {
 e.printStackTrace();
 } catch (IllegalAccessException e) {
 e.printStackTrace();
 }

 return null;
}
}

Thread Dump:

"ApplicationImpl pooled thread 1@1377" prio=4 tid=0x10 nid=NA waiting
 java.lang.Thread.State: WAITING
 at sun.misc.Unsafe.park(Unsafe.java:-1)
 at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
 at java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:458)
 at java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:362)
 at java.util.concurrent.SynchronousQueue.take(SynchronousQueue.java:924)
 at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
 at java.lang.Thread.run(Thread.java:745)

"Periodic tasks thread@1168" prio=5 tid=0xd nid=NA waiting
 java.lang.Thread.State: WAITING
 at sun.misc.Unsafe.park(Unsafe.java:-1)
 at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215)
 at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078)
 at java.util.concurrent.DelayQueue.take(DelayQueue.java:223)
 at com.intellij.util.concurrency.AppDelayQueue$1.run(AppDelayQueue.java:42)
 at java.lang.Thread.run(Thread.java:745)

"AWT-Shutdown@1172" prio=5 tid=0xe nid=NA waiting
 java.lang.Thread.State: WAITING
 at java.lang.Object.wait(Object.java:-1)
 at java.lang.Object.wait(Object.java:502)
 at sun.awt.AWTAutoShutdown.run(AWTAutoShutdown.java:295)
 at java.lang.Thread.run(Thread.java:745)

"Finalizer@1381" daemon prio=8 tid=0x3 nid=NA waiting
 java.lang.Thread.State: WAITING
 at java.lang.Object.wait(Object.java:-1)
 at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
 at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:164)
 at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:209)

"Reference Handler@1382" daemon prio=10 tid=0x2 nid=NA waiting
 java.lang.Thread.State: WAITING
 at java.lang.Object.wait(Object.java:-1)
 at java.lang.Object.wait(Object.java:502)
 at java.lang.ref.Reference.tryHandlePending(Reference.java:191)
 at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)

"DestroyJavaVM@1375" prio=5 tid=0xf nid=NA runnable
 java.lang.Thread.State: RUNNABLE

"Signal Dispatcher@1380" daemon prio=9 tid=0x4 nid=NA runnable
 java.lang.Thread.State: RUNNABLE

Thank you in advance!
Best Regards