Bug 1213: Refine changes .. comments and API

- Use InterruptSource.Thread.create(..),
  while reducing InterruptSource.Thread ctors to 3 variants.

- Use InterruptSource.Thread instead of java.lang.Thread where possible

- Use SourcedInterruptedException where possible

- SingletonInstanceServerSocket: start(), stop() and run()
  - Persistent-Wait and Cancelable

- Add @since 2.3.2

12 files changed, 147 insertions, 79 deletions

diff --git a/make/scripts/runtest.sh b/make/scripts/runtest.sh
index 8b7ed11..c3b5331 100755
--- a/make/scripts/runtest.sh
+++ b/make/scripts/runtest.sh
@@ -56,7 +56,7 @@ X_ARGS="-Drootrel.build=$ROOTREL_BUILD -Dgluegen.root=$GLUEGEN_ROOT"
 #D_ARGS="-Djogamp.debug.JNILibLoader -Djogamp.gluegen.UseTempJarCache=false"
 #D_ARGS="-Djogamp.debug.JNILibLoader -Djogamp.debug.TempJarCache"
 #D_ARGS="-Djogamp.debug.JNILibLoader"
-D_ARGS="-Djogamp.debug.JNILibLoader.Perf"
+#D_ARGS="-Djogamp.debug.JNILibLoader.Perf"
 #D_ARGS="-Djogamp.debug.Lock"
 #D_ARGS="-Djogamp.debug.Lock -Djogamp.debug.Lock.TraceLock"
 #D_ARGS="-Djogamp.debug.Lock.TraceLock"
@@ -87,7 +87,7 @@ function onetest() {
     echo
 }
 #
-onetest com.jogamp.common.GlueGenVersion 2>&1 | tee -a $LOG
+#onetest com.jogamp.common.GlueGenVersion 2>&1 | tee -a $LOG
 #onetest com.jogamp.common.util.TestSystemPropsAndEnvs 2>&1 | tee -a $LOG
 #onetest com.jogamp.common.util.TestVersionInfo 2>&1 | tee -a $LOG
 #onetest com.jogamp.common.util.TestVersionNumber 2>&1 | tee -a $LOG
@@ -95,7 +95,7 @@ onetest com.jogamp.common.GlueGenVersion 2>&1 | tee -a $LOG
 #onetest com.jogamp.common.util.TestIteratorIndexCORE 2>&1 | tee -a $LOG
 #onetest com.jogamp.common.util.locks.TestRecursiveLock01 2>&1 | tee -a $LOG
 #onetest com.jogamp.common.util.locks.TestRecursiveThreadGroupLock01 2>&1 | tee -a $LOG
-#onetest com.jogamp.common.util.locks.TestSingletonServerSocket00 2>&1 | tee -a $LOG
+onetest com.jogamp.common.util.locks.TestSingletonServerSocket00 2>&1 | tee -a $LOG
 #onetest com.jogamp.common.util.locks.TestSingletonServerSocket01 2>&1 | tee -a $LOG
 #onetest com.jogamp.common.util.locks.TestSingletonServerSocket02 2>&1 | tee -a $LOG
 #onetest com.jogamp.common.util.TestFloatStack01 2>&1 | tee -a $LOG
diff --git a/src/java/com/jogamp/common/util/FunctionTask.java b/src/java/com/jogamp/common/util/FunctionTask.java
index 5a58a34..630ae2f 100644
--- a/src/java/com/jogamp/common/util/FunctionTask.java
+++ b/src/java/com/jogamp/common/util/FunctionTask.java
@@ -49,30 +49,32 @@ public class FunctionTask<R,A> extends TaskBase implements Function<R,A> {
     }
 
     /**
-     * Invokes <code>func</code> on a new thread belonging to the given {@link ThreadGroup}.
+     * Invokes <code>func</code> on a new {@link InterruptSource.Thread},
+     * see {@link InterruptSource.Thread#Thread(ThreadGroup, Runnable, String)} for details.
      * <p>
      * The result can be retrieved via {@link FunctionTask#getResult()},
      * using the returned instance.
      * </p>
      * @param tg the {@link ThreadGroup} for the new thread, maybe <code>null</code>
-     * @param threadName the name for the new thread
+     * @param threadName the name for the new thread, maybe <code>null</code>
      * @param waitUntilDone if <code>true</code>, waits until <code>func</code> execution is completed, otherwise returns immediately.
      * @param func the {@link Function} to execute.
      * @param args the {@link Function} arguments
      * @return the newly created and invoked {@link FunctionTask}
+     * @since 2.3.2
      */
     public static <U,V> FunctionTask<U,V> invokeOnNewThread(final ThreadGroup tg, final String threadName,
                                                             final boolean waitUntilDone, final Function<U,V> func, final V... args) {
         final FunctionTask<U,V> rt;
         if( !waitUntilDone ) {
             rt = new FunctionTask<U,V>( func, null, true, System.err );
-            final InterruptSource.Thread t = new InterruptSource.Thread(tg, rt, threadName);
+            final InterruptSource.Thread t = InterruptSource.Thread.create(tg, rt, threadName);
             rt.args = args;
             t.start();
         } else {
             final Object sync = new Object();
             rt = new FunctionTask<U,V>( func, sync, true, null );
-            final InterruptSource.Thread t = new InterruptSource.Thread(tg, rt, threadName);
+            final InterruptSource.Thread t = InterruptSource.Thread.create(tg, rt, threadName);
             synchronized(sync) {
                 rt.args = args;
                 t.start();
diff --git a/src/java/com/jogamp/common/util/InterruptSource.java b/src/java/com/jogamp/common/util/InterruptSource.java
index 1d43961..01fcdb5 100644
--- a/src/java/com/jogamp/common/util/InterruptSource.java
+++ b/src/java/com/jogamp/common/util/InterruptSource.java
@@ -31,6 +31,7 @@ package com.jogamp.common.util;
 /**
  * Interface exposing {@link java.lang.Thread#interrupt()} source,
  * intended for {@link java.lang.Thread} specializations.
+ * @since 2.3.2
  */
 public interface InterruptSource {
     /**
@@ -52,7 +53,7 @@ public interface InterruptSource {
 
     public static class Util {
         /**
-         * Casts given {@link java.lang.Thread} to {@link InterruptSource},
+         * Casts given {@link java.lang.Thread} to {@link InterruptSource}
          * if applicable, otherwise returns {@code null}.
          */
         public static InterruptSource get(final java.lang.Thread t) {
@@ -63,7 +64,7 @@ public interface InterruptSource {
             }
         }
         /**
-         * Casts current {@link java.lang.Thread} to {@link InterruptSource},
+         * Casts current {@link java.lang.Thread} to {@link InterruptSource}
          * if applicable, otherwise returns {@code null}.
          */
         public static InterruptSource currentThread() {
@@ -74,25 +75,49 @@ public interface InterruptSource {
     /**
      * {@link java.lang.Thread} specialization implementing {@link InterruptSource}
      * to track {@link java.lang.Thread#interrupt()} calls.
+     * @since 2.3.2
      */
     public static class Thread extends java.lang.Thread implements InterruptSource {
         volatile Throwable interruptSource = null;
         volatile int interruptCounter = 0;
         final Object sync = new Object();
 
-        public Thread(final String name) {
-            super(name);
-        }
-        public Thread(final Runnable target) {
-            super(target);
+        /**
+         * See {@link Thread#Thread(} for details.
+         */
+        public Thread() {
+            super();
         }
-        public Thread(final Runnable target, final String name) {
-            super(target, name);
+        /**
+         * See {@link Thread#Thread(ThreadGroup, Runnable)} for details.
+         * @param tg explicit {@link ThreadGroup}, may be {@code null}
+         * @param target explicit {@link Runnable}, may be {@code null}
+         */
+        public Thread(final ThreadGroup tg, final Runnable target) {
+            super(tg, target);
         }
+        /**
+         * See {@link Thread#Thread(ThreadGroup, Runnable, String)} for details.
+         * @param tg explicit {@link ThreadGroup}, may be {@code null}
+         * @param target explicit {@link Runnable}, may be {@code null}
+         * @param name explicit name of thread, must not be {@code null}
+         */
         public Thread(final ThreadGroup tg, final Runnable target, final String name) {
             super(tg, target, name);
         }
 
+        /**
+         * Depending on whether {@code name} is null, either
+         * {@link #Thread(ThreadGroup, Runnable, String)} or
+         * {@link #Thread(ThreadGroup, Runnable)} is being utilized.
+         * @param tg explicit {@link ThreadGroup}, may be {@code null}
+         * @param target explicit {@link Runnable}, may be {@code null}
+         * @param name explicit name of thread, may be {@code null}
+         */
+        public static Thread create(final ThreadGroup tg, final Runnable target, final String name) {
+            return null != name ? new Thread(tg, target, name) : new Thread(tg, target);
+        }
+
         @Override
         public final Throwable getInterruptSource(final boolean clear) {
             synchronized(sync) {
diff --git a/src/java/com/jogamp/common/util/RunnableTask.java b/src/java/com/jogamp/common/util/RunnableTask.java
index 69d7af2..57809b9 100644
--- a/src/java/com/jogamp/common/util/RunnableTask.java
+++ b/src/java/com/jogamp/common/util/RunnableTask.java
@@ -55,25 +55,27 @@ public class RunnableTask extends TaskBase {
     }
 
     /**
-     * Invokes <code>runnable</code> on a new thread belonging to the given {@link ThreadGroup}.
+     * Invokes <code>runnable</code> on a new {@link InterruptSource.Thread},
+     * see {@link InterruptSource.Thread#Thread(ThreadGroup, Runnable, String)} for details.
      * @param tg the {@link ThreadGroup} for the new thread, maybe <code>null</code>
+     * @param threadName the name for the new thread, maybe <code>null</code>
      * @param waitUntilDone if <code>true</code>, waits until <code>runnable</code> execution is completed, otherwise returns immediately.
      * @param runnable the {@link Runnable} to execute on the new thread. If <code>waitUntilDone</code> is <code>true</code>,
-     *                 the runnable <b>must exist</b>, i.e. not loop forever.
-     * @param threadName the name for the new thread
+     *                 the runnable <b>must exit</b>, i.e. not loop forever.
      * @return the newly created and invoked {@link RunnableTask}
+     * @since 2.3.2
      */
     public static RunnableTask invokeOnNewThread(final ThreadGroup tg, final String threadName,
                                                  final boolean waitUntilDone, final Runnable runnable) {
         final RunnableTask rt;
         if( !waitUntilDone ) {
             rt = new RunnableTask( runnable, null, true, System.err );
-            final InterruptSource.Thread t = new InterruptSource.Thread(tg, rt, threadName);
+            final InterruptSource.Thread t = InterruptSource.Thread.create(tg, rt, threadName);
             t.start();
         } else {
             final Object sync = new Object();
             rt = new RunnableTask( runnable, sync, true, null );
-            final InterruptSource.Thread t = new InterruptSource.Thread(tg, rt, threadName);
+            final InterruptSource.Thread t = InterruptSource.Thread.create(tg, rt, threadName);
             synchronized(sync) {
                 t.start();
                 while( rt.isInQueue() ) {
diff --git a/src/java/com/jogamp/common/util/SourcedInterruptedException.java b/src/java/com/jogamp/common/util/SourcedInterruptedException.java
index 7646652..49dcd86 100644
--- a/src/java/com/jogamp/common/util/SourcedInterruptedException.java
+++ b/src/java/com/jogamp/common/util/SourcedInterruptedException.java
@@ -39,6 +39,7 @@ import com.jogamp.common.ExceptionUtils.CustomStackTrace;
  * This exception may be created directly where {@link #getCause()} returns {@code null},
  * or by propagating an existing {@link InterruptedException} as returned by {@link #getCause()}.
  * </p>
+ * @since 2.3.2
  */
 @SuppressWarnings("serial")
 public class SourcedInterruptedException extends InterruptedException implements CustomStackTrace {
diff --git a/src/java/com/jogamp/common/util/TaskBase.java b/src/java/com/jogamp/common/util/TaskBase.java
index 518aeba..0fe85e4 100644
--- a/src/java/com/jogamp/common/util/TaskBase.java
+++ b/src/java/com/jogamp/common/util/TaskBase.java
@@ -80,7 +80,10 @@ public abstract class TaskBase implements Runnable {
         }
     }
 
-    /** Returns the execution thread or {@code null} if not yet {@link #run()}. */
+    /**
+     * Returns the execution thread or {@code null} if not yet {@link #run()}.
+     * @since 2.3.2
+     */
     public final Thread getExecutionThread() {
         return execThread;
     }
@@ -135,7 +138,7 @@ public abstract class TaskBase implements Runnable {
     /**
      * @return !{@link #isExecuted()} && !{@link #isFlushed()}
      */
-    public final boolean isInQueue() { return !isExecuted() && !isFlushed(); }
+    public final boolean isInQueue() { return !isExecuted && !isFlushed; }
 
     /**
      * @return True if executed, otherwise false;
diff --git a/src/java/com/jogamp/common/util/cache/TempFileCache.java b/src/java/com/jogamp/common/util/cache/TempFileCache.java
index 24f0237..44c7a11 100644
--- a/src/java/com/jogamp/common/util/cache/TempFileCache.java
+++ b/src/java/com/jogamp/common/util/cache/TempFileCache.java
@@ -35,6 +35,7 @@ import java.nio.channels.FileChannel;
 import java.nio.channels.FileLock;
 
 import com.jogamp.common.util.IOUtil;
+import com.jogamp.common.util.InterruptSource;
 
 import jogamp.common.Debug;
 
@@ -238,7 +239,7 @@ public class TempFileCache {
             // Add shutdown hook to cleanup the OutputStream, FileChannel,
             // and FileLock for the jlnNNNN.lck and jlnNNNN.lck files.
             // We do this so that the locks never get garbage-collected.
-            Runtime.getRuntime().addShutdownHook(new Thread() {
+            Runtime.getRuntime().addShutdownHook(new InterruptSource.Thread() {
                 /* @Override */
                 @Override
                 public void run() {
@@ -265,7 +266,7 @@ public class TempFileCache {
             }
 
             // Start a new Reaper thread to do stuff...
-            final Thread reaperThread = new Thread() {
+            final Thread reaperThread = new InterruptSource.Thread() {
                 /* @Override */
                 @Override
                 public void run() {
diff --git a/src/java/jogamp/android/launcher/LauncherTempFileCache.java b/src/java/jogamp/android/launcher/LauncherTempFileCache.java
index 6836dd9..b576ed9 100644
--- a/src/java/jogamp/android/launcher/LauncherTempFileCache.java
+++ b/src/java/jogamp/android/launcher/LauncherTempFileCache.java
@@ -34,6 +34,8 @@ import java.io.IOException;
 import java.nio.channels.FileChannel;
 import java.nio.channels.FileLock;
 
+import com.jogamp.common.util.InterruptSource;
+
 import android.content.Context;
 
 public class LauncherTempFileCache {
@@ -223,7 +225,7 @@ public class LauncherTempFileCache {
                 // Add shutdown hook to cleanup the OutputStream, FileChannel,
                 // and FileLock for the jlnNNNN.lck and jlnNNNN.lck files.
                 // We do this so that the locks never get garbage-collected.
-                Runtime.getRuntime().addShutdownHook(new Thread() {
+                Runtime.getRuntime().addShutdownHook(new InterruptSource.Thread() {
                     /* @Override */
                     public void run() {
                         // NOTE: we don't really expect that this code will ever
@@ -249,7 +251,7 @@ public class LauncherTempFileCache {
                 }
 
                 // Start a new Reaper thread to do stuff...
-                final Thread reaperThread = new Thread() {
+                final Thread reaperThread = new InterruptSource.Thread() {
                     /* @Override */
                     public void run() {
                         deleteOldTempDirs();
diff --git a/src/java/jogamp/common/util/locks/RecursiveLockImpl01CompleteFair.java b/src/java/jogamp/common/util/locks/RecursiveLockImpl01CompleteFair.java
index f86dd33..1286924 100644
--- a/src/java/jogamp/common/util/locks/RecursiveLockImpl01CompleteFair.java
+++ b/src/java/jogamp/common/util/locks/RecursiveLockImpl01CompleteFair.java
@@ -32,6 +32,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.locks.AbstractOwnableSynchronizer;
 
+import com.jogamp.common.util.SourcedInterruptedException;
 import com.jogamp.common.util.locks.RecursiveLock;
 
 /**
@@ -197,7 +198,7 @@ public class RecursiveLockImpl01CompleteFair implements RecursiveLock {
                     } catch (final InterruptedException e) {
                         if( !wCur.signaledByUnlock ) {
                             sync.queue.remove(wCur); // O(n)
-                            throw e; // propagate interruption not send by unlock
+                            throw SourcedInterruptedException.wrap(e); // propagate interruption not send by unlock
                         } else if( cur != sync.getOwner() ) {
                             // Issued by unlock, but still locked by other thread
                             //
diff --git a/src/java/jogamp/common/util/locks/SingletonInstanceServerSocket.java b/src/java/jogamp/common/util/locks/SingletonInstanceServerSocket.java
index b1b42c3..8ac73fa 100644
--- a/src/java/jogamp/common/util/locks/SingletonInstanceServerSocket.java
+++ b/src/java/jogamp/common/util/locks/SingletonInstanceServerSocket.java
@@ -33,10 +33,16 @@ import java.net.InetAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.net.UnknownHostException;
+
+import com.jogamp.common.ExceptionUtils;
+import com.jogamp.common.util.InterruptSource;
+import com.jogamp.common.util.InterruptedRuntimeException;
+import com.jogamp.common.util.SourcedInterruptedException;
 import com.jogamp.common.util.locks.SingletonInstance;
 
 public class SingletonInstanceServerSocket extends SingletonInstance {
 
+    private static int serverInstanceCount = 0;
     private final Server singletonServer;
     private final String fullName;
 
@@ -139,38 +145,58 @@ public class SingletonInstanceServerSocket extends SingletonInstance {
        public final boolean start() {
            if(alive) return true;
 
+           final String sname;
+           synchronized (Server.class) {
+               serverInstanceCount++;
+               sname = "SingletonServerSocket"+serverInstanceCount+"-"+fullName;
+           }
            synchronized (syncOnStartStop) {
-               serverThread = new Thread(this);
+               shallQuit = false;
+               serverThread = InterruptSource.Thread.create(null, this, sname);
                serverThread.setDaemon(true);  // be a daemon, don't keep the JVM running
                serverThread.start();
                try {
-                   syncOnStartStop.wait();
+                   while( !alive && !shallQuit ) {
+                       syncOnStartStop.wait();
+                   }
                } catch (final InterruptedException ie) {
-                   ie.printStackTrace();
+                   final InterruptedException ie2 = SourcedInterruptedException.wrap(ie);
+                   shutdown(false);
+                   throw new InterruptedRuntimeException(ie2);
                }
            }
            final boolean ok = isBound();
            if(!ok) {
-               shutdown();
+               shutdown(true);
            }
            return ok;
        }
 
        public final boolean shutdown() {
+           return shutdown(true);
+       }
+       private final boolean shutdown(final boolean wait) {
            if(!alive) return true;
 
-           synchronized (syncOnStartStop) {
-               shallQuit = true;
-               connect();
-               try {
-                   syncOnStartStop.wait();
-               } catch (final InterruptedException ie) {
-                   ie.printStackTrace();
+           try {
+               synchronized (syncOnStartStop) {
+                   shallQuit = true;
+                   connect();
+                   if( wait ) {
+                       try {
+                           while( alive ) {
+                               syncOnStartStop.wait();
+                           }
+                       } catch (final InterruptedException ie) {
+                           throw new InterruptedRuntimeException(ie);
+                       }
+                   }
+               }
+           } finally {
+               if(alive) {
+                   System.err.println(infoPrefix()+" EEE "+getName()+" - Unable to remove lock: ServerThread still alive ?");
+                   kill();
                }
-           }
-           if(alive) {
-               System.err.println(infoPrefix()+" EEE "+getName()+" - Unable to remove lock: ServerThread still alive ?");
-               kill();
            }
            return true;
        }
@@ -185,7 +211,8 @@ public class SingletonInstanceServerSocket extends SingletonInstance {
                 System.err.println(infoPrefix()+" XXX "+getName()+" - Kill @ JVM Shutdown");
            }
            alive = false;
-           if(null != serverThread) {
+           shallQuit = false;
+           if(null != serverThread && serverThread.isAlive() ) {
                try {
                    serverThread.stop();
                } catch(final Throwable t) { }
@@ -214,47 +241,49 @@ public class SingletonInstanceServerSocket extends SingletonInstance {
 
        @Override
        public void run() {
-           {
-               final Thread currentThread = Thread.currentThread();
-               currentThread.setName(currentThread.getName() + " - SISock: "+getName());
-               if(DEBUG) {
-                   System.err.println(currentThread.getName()+" - started");
-               }
+           if(DEBUG) {
+               System.err.println(infoPrefix()+" III - Start");
            }
-           alive = false;
-           synchronized (syncOnStartStop) {
-               try {
-                   serverSocket = new ServerSocket(portNumber, 1, localInetAddress);
-                   serverSocket.setReuseAddress(true); // reuse same port w/ subsequent instance, i.e. overcome TO state when JVM crashed
-                   alive = true;
-               } catch (final IOException e) {
-                    System.err.println(infoPrefix()+" III - Unable to install ServerSocket: "+e.getMessage());
-                    shallQuit = true;
-               } finally {
-                    syncOnStartStop.notifyAll();
+           try {
+               synchronized (syncOnStartStop) {
+                   try {
+                       serverSocket = new ServerSocket(portNumber, 1, localInetAddress);
+                       serverSocket.setReuseAddress(true); // reuse same port w/ subsequent instance, i.e. overcome TO state when JVM crashed
+                       alive = true;
+                   } catch (final IOException e) {
+                       System.err.println(infoPrefix()+" III - Unable to install ServerSocket: "+e.getMessage());
+                       shallQuit = true;
+                   } finally {
+                       syncOnStartStop.notifyAll();
+                   }
                }
-           }
 
-           while (!shallQuit) {
-               try {
-                   final Socket clientSocket = serverSocket.accept();
-                   clientSocket.close();
-               } catch (final IOException ioe) {
-                   System.err.println(infoPrefix()+" EEE - Exception during accept: " + ioe.getMessage());
+               while (!shallQuit) {
+                   try {
+                       final Socket clientSocket = serverSocket.accept();
+                       clientSocket.close();
+                   } catch (final IOException ioe) {
+                       System.err.println(infoPrefix()+" EEE - Exception during accept: " + ioe.getMessage());
+                   }
                }
-           }
-
-           synchronized (syncOnStartStop) {
-               try {
+           } catch(final ThreadDeath td) {
+               if( DEBUG ) {
+                   ExceptionUtils.dumpThrowable("", td);
+               }
+           } finally {
+               synchronized (syncOnStartStop) {
+                   if(DEBUG) {
+                       System.err.println(infoPrefix()+" III - Stopping: alive "+alive+", shallQuit "+shallQuit+", hasSocket "+(null!=serverSocket));
+                   }
                    if(null != serverSocket) {
-                       serverSocket.close();
+                       try {
+                           serverSocket.close();
+                       } catch (final IOException e) {
+                           System.err.println(infoPrefix()+" EEE - Exception during close: " + e.getMessage());
+                       }
                    }
-               } catch (final IOException e) {
-                   System.err.println(infoPrefix()+" EEE - Exception during close: " + e.getMessage());
-               } finally {
                    serverSocket = null;
                    alive = false;
-                   shallQuit = false;
                    syncOnStartStop.notifyAll();
                }
            }
diff --git a/src/junit/com/jogamp/common/util/locks/TestSingletonServerSocket00.java b/src/junit/com/jogamp/common/util/locks/TestSingletonServerSocket00.java
index b018a79..a1a9965 100644
--- a/src/junit/com/jogamp/common/util/locks/TestSingletonServerSocket00.java
+++ b/src/junit/com/jogamp/common/util/locks/TestSingletonServerSocket00.java
@@ -35,10 +35,11 @@ import org.junit.Test;
 import org.junit.FixMethodOrder;
 import org.junit.runners.MethodSorters;
 
+import com.jogamp.junit.util.JunitTracer;
 import com.jogamp.junit.util.SingletonJunitCase;
 
 @FixMethodOrder(MethodSorters.NAME_ASCENDING)
-public class TestSingletonServerSocket00 {
+public class TestSingletonServerSocket00 extends JunitTracer {
     public static final long SINGLE_INSTANCE_LOCK_TO   = SingletonJunitCase.SINGLE_INSTANCE_LOCK_TO;
 
     public static final long SINGLE_INSTANCE_LOCK_POLL = 100; // poll every 100ms
diff --git a/src/junit/com/jogamp/common/util/locks/TestSingletonServerSocket01.java b/src/junit/com/jogamp/common/util/locks/TestSingletonServerSocket01.java
index b37e600..c637865 100644
--- a/src/junit/com/jogamp/common/util/locks/TestSingletonServerSocket01.java
+++ b/src/junit/com/jogamp/common/util/locks/TestSingletonServerSocket01.java
@@ -35,10 +35,11 @@ import org.junit.Test;
 import org.junit.FixMethodOrder;
 import org.junit.runners.MethodSorters;
 
+import com.jogamp.junit.util.JunitTracer;
 import com.jogamp.junit.util.SingletonJunitCase;
 
 @FixMethodOrder(MethodSorters.NAME_ASCENDING)
-public class TestSingletonServerSocket01 {
+public class TestSingletonServerSocket01 extends JunitTracer {
     private static volatile SingletonInstance singletonInstance;
 
     @BeforeClass