diff --git a/make/build-junit.xml b/make/build-junit.xml
index ad625ba2..82f87a16 100644
--- a/make/build-junit.xml
+++ b/make/build-junit.xml
@@ -35,6 +35,8 @@
         <property name="build_t.obj"  value="${build_t}/obj"/>
         <property name="build_t.lib"  value="${build_t}/natives"/>
 
+        <property name="batchtest.timeout"    value="1800000"/> <!-- 30 min -->
+
         <property name="build_t.gen.rootrel" value="${rootrel.build}/test/build/gensrc"/>
 
         <mkdir dir="${test.dir}"/>
@@ -196,7 +198,7 @@
         <property name="build_t.lib.abs" location="${build_t.lib}" />
 
         <!-- Perform the junit tests-->
-        <junit forkmode="once" showoutput="true" fork="true">
+        <junit forkmode="once" showoutput="true" fork="true" timeout="${batchtest.timeout}">
             <env key="${system.env.library.path}" path="${gluegen.lib.abs}${path.separator}${build_t.lib.abs}"/>
             <jvmarg value="-Djava.library.path=${gluegen.lib.abs}${path.separator}${build_t.lib.abs}"/>
             <jvmarg value="-Drootrel.build=${rootrel.build}"/>
@@ -214,6 +216,7 @@
             <batchtest todir="${results}">
               <fileset dir="${build_t.java}">
                   <include name="${test.junit.rel}/**/*Test*"/>
+                  <exclude name="**/*$$*"/>
               </fileset>
               <formatter usefile="false" type="brief"/>
               <formatter usefile="true" type="xml"/>
diff --git a/src/junit/com/jogamp/common/util/TestRecursiveToolkitLock.java b/src/junit/com/jogamp/common/util/TestRecursiveToolkitLock.java
new file mode 100644
index 00000000..ea2e925d
--- /dev/null
+++ b/src/junit/com/jogamp/common/util/TestRecursiveToolkitLock.java
@@ -0,0 +1,279 @@
+/**
+ * Copyright 2010 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ * 
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ * 
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+ 
+package com.jogamp.common.util;
+
+import java.lang.reflect.*;
+import java.io.IOException;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Test;
+
+public class TestRecursiveToolkitLock {
+
+    static final int YIELD_NONE = 0;
+    static final int YIELD_YIELD = 1;
+    static final int YIELD_SLEEP = 2;
+
+    static void yield(int mode) {
+        switch(mode) {
+            case YIELD_YIELD:
+                Thread.yield();
+                break;
+            case YIELD_SLEEP:
+                try {
+                    Thread.sleep(20);
+                } catch (InterruptedException ie) {
+                    ie.printStackTrace();
+                }
+                break;
+            default:
+                break;
+        }
+
+    }
+
+    static class LockedObject {
+        static final boolean DEBUG = false;
+
+        public LockedObject() {
+            locker = new RecursiveToolkitLock();
+            actionCounter = 0;
+        }
+
+        public final void action1Direct(int l, int yieldMode) {
+            if(DEBUG) {
+                System.err.print("<a1");
+            }
+            lock();
+            try {
+                if(DEBUG) {
+                    System.err.print("+");
+                }
+                while(l>0) l--;
+                actionCounter++;
+                yield(yieldMode);
+            } finally {
+                if(DEBUG) {
+                    System.err.print("-");
+                }
+                unlock();
+                if(DEBUG) {
+                    System.err.println(">");
+                }
+            }
+        }
+
+        class Action2 implements Runnable {
+            int l, yieldMode;
+            Action2(int l, int yieldMode) {
+                this.l=l;
+                this.yieldMode=yieldMode;
+            }
+            public void run() {
+                if(DEBUG) {
+                    System.err.print("[a2");
+                }
+                lock();
+                try {
+                    if(DEBUG) {
+                        System.err.print("+");
+                    }
+                    while(l>0) l--;
+                    actionCounter++;
+                    yield(yieldMode);
+                } finally {
+                    if(DEBUG) {
+                        System.err.print("-");
+                    }
+                    unlock();
+                    if(DEBUG) {
+                        System.err.println("]");
+                    }
+                }
+            }
+        }
+
+        public final void action2Deferred(int l, int yieldMode) {
+            Thread thread = new Thread(new Action2(l, yieldMode), Thread.currentThread()+"-action2Deferred");
+            thread.start();
+        }
+
+        public final void lock() {
+            locker.lock();
+        }
+
+        public final void unlock() {
+            locker.unlock();
+        }
+
+        public final boolean isLocked() {
+            return locker.isLocked();
+        }
+
+        RecursiveToolkitLock locker;
+        int actionCounter;
+    }
+
+    interface LockedObjectIf extends Runnable {
+        void stop();
+        boolean isStopped();
+        int remaining();
+    }
+
+    class LockedObjectAction1 implements LockedObjectIf {
+        boolean shouldStop;
+        boolean stopped;
+        LockedObject lo;
+        volatile int loops;
+        int iloops;
+        int yieldMode;
+
+        public LockedObjectAction1(LockedObject lo, int loops, int iloops, int yieldMode) {
+            this.lo = lo;
+            this.loops = loops;
+            this.iloops = iloops;
+            this.shouldStop = false;
+            this.stopped = false;
+            this.yieldMode = yieldMode;
+        }
+
+        public final synchronized void stop() {
+            shouldStop = true;
+        }
+
+        public final synchronized boolean isStopped() {
+            return stopped;
+        }
+
+        public final int remaining() {
+            return loops;
+        }
+
+        public void run() {
+            while(!shouldStop && loops>0) {
+                lo.action1Direct(iloops, yieldMode);
+                lo.action2Deferred(iloops, yieldMode);
+                loops--;
+            }
+            synchronized(this) {
+                stopped = true;
+                notifyAll();
+            }
+        }
+    }
+
+    protected void testLockedObjectImpl(int threadNum, int loops, int iloops, int yieldMode) throws InterruptedException {
+        LockedObject lo = new LockedObject();
+        LockedObjectIf[] runners = new LockedObjectIf[threadNum];
+        Thread[] threads = new Thread[threadNum];
+        int i;
+
+        for(i=0; i<threadNum; i++) {
+            runners[i] = new LockedObjectAction1(lo, loops, iloops, yieldMode);
+            threads[i] = new Thread( runners[i], Thread.currentThread()+"-ActionThread-"+i+"/"+threadNum);
+            threads[i].start();
+        }
+
+        int active;
+        do {
+            active = threadNum;
+            for(i=0; i<threadNum; i++) {
+                if(runners[i].isStopped()) {
+                    active--;
+                }
+            }
+            yield(yieldMode);
+        } while(0<active);
+    }
+
+    // @Test
+    public void testLockedObjectThreading2x10000() throws InterruptedException {
+        System.err.println("++++ TestRecursiveToolkitLock.testLockedObjectThreading2x10000");
+        testLockedObjectImpl(2, 10000, 10000, YIELD_NONE);
+        System.err.println("---- TestRecursiveToolkitLock.testLockedObjectThreading2x10000");
+    }
+
+    @Test
+    public void testLockedObjectThreading200x200Yield() throws InterruptedException {
+        System.err.println("++++ TestRecursiveToolkitLock.testLockedObjectThreading200x200-Yield");
+        testLockedObjectImpl(200, 200, 100, YIELD_YIELD);
+        System.err.println("---- TestRecursiveToolkitLock.testLockedObjectThreading200x200-Yield");
+    }
+
+    // @Test
+    public void testLockedObjectThreading200x200Sleep() throws InterruptedException {
+        System.err.println("++++ TestRecursiveToolkitLock.testLockedObjectThreading200x200-Sleep");
+        testLockedObjectImpl(200, 200, 100, YIELD_SLEEP);
+        System.err.println("---- TestRecursiveToolkitLock.testLockedObjectThreading200x200-Sleep");
+    }
+
+    @Test
+    public void testLockedObjectThreading200x200None() throws InterruptedException {
+        System.err.println("++++ TestRecursiveToolkitLock.testLockedObjectThreading200x200-None");
+        testLockedObjectImpl(200, 200, 100, YIELD_NONE);
+        System.err.println("---- TestRecursiveToolkitLock.testLockedObjectThreading200x200-None");
+    }
+
+    static int atoi(String a) {
+        int i=0;
+        try {
+            i = Integer.parseInt(a);
+        } catch (Exception ex) { ex.printStackTrace(); }
+        return i;
+    }
+
+    public static void main(String args[]) throws IOException {
+        /*for(int i=0; i<args.length; i++) {
+            if(args[i].equals("-time")) {
+                durationPerTest = atoi(args[++i]);
+            }
+        }
+        System.out.println("durationPerTest: "+durationPerTest);
+        */
+        String tstname = TestRecursiveToolkitLock.class.getName();
+        /*
+        org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.main(new String[] {
+            tstname,
+            "filtertrace=true",
+            "haltOnError=false",
+            "haltOnFailure=false",
+            "showoutput=true",
+            "outputtoformatters=true",
+            "logfailedtests=true",
+            "logtestlistenerevents=true",
+            "formatter=org.apache.tools.ant.taskdefs.optional.junit.PlainJUnitResultFormatter",
+            "formatter=org.apache.tools.ant.taskdefs.optional.junit.XMLJUnitResultFormatter,TEST-"+tstname+".xml" } ); */
+        org.junit.runner.JUnitCore.main(tstname);
+    }
+
+}