Fix: NativeWindow RecursiveToolkitLock, GLWindow lockSurface/unlockSurface

Fix: NativeWindow RecursiveToolkitLock
    - Use notify(), instead of notifyAll(), so only one thread is being awakened
      for the single resource. Otherwise starvation and timeout happen, since
      the oldest thread might not get waken up (earlier than other threads) within timeout.

    - Inner class for all synchronized (flow/mem) fields for easier fine grained sync/lock.

Fix: GLWindow lockSurface/unlockSurface
    - Enter locked surface block only if surface lock could be acquired

8 files changed, 421 insertions, 89 deletions

diff --git a/make/scripts/java-run-all.sh b/make/scripts/java-run-all.sh
index 2b3fc21e7..6bb053a16 100755
--- a/make/scripts/java-run-all.sh
+++ b/make/scripts/java-run-all.sh
@@ -48,6 +48,7 @@ uname -a | grep -i Darwin && MOSX=1
 # D_ARGS="-Dnewt.debug.EDT -Dnewt.debug.Window"
 # D_ARGS="-Dsun.awt.disableMixing=true -Dnewt.debug.EDT"
 D_ARGS="-Dnewt.debug.EDT"
+# D_ARGS="-Dnativewindow.debug.TraceLock"
 # D_ARGS="-Dnewt.debug.Display"
 # D_ARGS="-Djogl.debug.Animator -Dnewt.debug.Window -Dnewt.debug.Display"
 # D_ARGS="-Dnewt.debug.Window -Dnewt.debug.Display -Dnewt.test.Window.reparent.incompatible=true"
diff --git a/make/scripts/tests.bat b/make/scripts/tests.bat
index 82dba1c9b..f9bc7a5c8 100644
--- a/make/scripts/tests.bat
+++ b/make/scripts/tests.bat
@@ -12,4 +12,6 @@ REM # ./scripts/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.paren
 REM # ./scripts/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.TestGLWindows01NEWT
 REM # ./scripts/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.TestGLWindows02NEWTAnimated
 REM scripts\java-win64-dbg.bat com.jogamp.test.junit.newt.parenting.TestParenting01NEWT
-scripts\java-win64-dbg.bat com.jogamp.test.junit.newt.TestFocus01SwingAWT
+scripts\java-win64-dbg.bat com.jogamp.test.junit.newt.TestFocus01SwingAWTRobot
+REM scripts\java-win64-dbg.bat com.jogamp.test.junit.newt.TestFocus01SwingAWTRobot
+REM scripts\java-win64-dbg.bat com.jogamp.test.junit.nativewindow.TestRecursiveToolkitLockCORE
diff --git a/make/scripts/tests.sh b/make/scripts/tests.sh
index 0e3688bb4..c5939e5e5 100755
--- a/make/scripts/tests.sh
+++ b/make/scripts/tests.sh
@@ -21,14 +21,16 @@ spath=`dirname $0`
 # $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.parenting.TestParenting02NEWT $*
 
 # $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.parenting.TestParenting01aAWT $*
-$spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.parenting.TestParenting01bAWT $*
+# $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.parenting.TestParenting01bAWT $*
 # $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.parenting.TestParenting01cAWT $*
 # $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.parenting.TestParenting01cSwingAWT $*
 # $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.parenting.TestParenting02AWT $*
 
 # $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.jogl.awt.TestSwingAWTRobotUsageBeforeJOGLInitBug411 $*
 
-# $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.TestFocus01SwingAWTRobot $*
+$spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.TestFocus01SwingAWTRobot $*
 # $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.newt.TestFocus02SwingAWTRobot $*
 
+# $spath/java-run-all.sh ../build-x86_64 com.jogamp.test.junit.nativewindow.TestRecursiveToolkitLockCORE $*
+
 $spath/count-edt-start.sh java-run.log
diff --git a/src/junit/com/jogamp/test/junit/nativewindow/TestRecursiveToolkitLockCORE.java b/src/junit/com/jogamp/test/junit/nativewindow/TestRecursiveToolkitLockCORE.java
new file mode 100644
index 000000000..7da448363
--- /dev/null
+++ b/src/junit/com/jogamp/test/junit/nativewindow/TestRecursiveToolkitLockCORE.java
@@ -0,0 +1,281 @@
+/**
+ * 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.test.junit.nativewindow;
+
+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;
+
+import com.jogamp.nativewindow.impl.RecursiveToolkitLock;
+
+public class TestRecursiveToolkitLockCORE {
+
+    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 testLockedObjectThreading1x100() throws InterruptedException {
+        System.err.println("++++ TestRecursiveToolkitLockCORE.testLockedObjectThreading1x100");
+        testLockedObjectImpl(1, 100, 100, YIELD_NONE);
+        System.err.println("---- TestRecursiveToolkitLockCORE.testLockedObjectThreading1x100");
+    }
+
+    @Test
+    public void testLockedObjectThreading200x200Yield() throws InterruptedException {
+        System.err.println("++++ TestRecursiveToolkitLockCORE.testLockedObjectThreading200x200-Yield");
+        testLockedObjectImpl(200, 200, 100, YIELD_YIELD);
+        System.err.println("---- TestRecursiveToolkitLockCORE.testLockedObjectThreading200x200-Yield");
+    }
+
+    // @Test
+    public void testLockedObjectThreading200x200Sleep() throws InterruptedException {
+        System.err.println("++++ TestRecursiveToolkitLockCORE.testLockedObjectThreading200x200-Sleep");
+        testLockedObjectImpl(200, 200, 100, YIELD_SLEEP);
+        System.err.println("---- TestRecursiveToolkitLockCORE.testLockedObjectThreading200x200-Sleep");
+    }
+
+    @Test
+    public void testLockedObjectThreading200x200None() throws InterruptedException {
+        System.err.println("++++ TestRecursiveToolkitLockCORE.testLockedObjectThreading200x200-None");
+        testLockedObjectImpl(200, 200, 100, YIELD_NONE);
+        System.err.println("---- TestRecursiveToolkitLockCORE.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 = TestRecursiveToolkitLockCORE.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);
+    }
+
+}
diff --git a/src/junit/com/jogamp/test/junit/util/UITestCase.java b/src/junit/com/jogamp/test/junit/util/UITestCase.java
index 200a96fe9..5bf76234d 100644
--- a/src/junit/com/jogamp/test/junit/util/UITestCase.java
+++ b/src/junit/com/jogamp/test/junit/util/UITestCase.java
@@ -28,7 +28,9 @@
  
 package com.jogamp.test.junit.util;
 
+import org.junit.Before;
 import org.junit.BeforeClass;
+import org.junit.After;
 import org.junit.AfterClass;
 
 import java.lang.reflect.InvocationTargetException;
@@ -55,5 +57,16 @@ public abstract class UITestCase {
         // one-time cleanup code
         singletonInstance.unlock();
     }
+
+    @Before
+    public void setUp() {
+        System.err.println("++++ UITestCase.setUp: "+getClass().getName());
+    }
+
+    @After
+    public void tearDown() {
+        System.err.println("++++ UITestCase.tearDown: "+getClass().getName());
+    }
+
 }
 
diff --git a/src/nativewindow/classes/com/jogamp/nativewindow/impl/RecursiveToolkitLock.java b/src/nativewindow/classes/com/jogamp/nativewindow/impl/RecursiveToolkitLock.java
index a894c616a..bfa3d32a5 100644
--- a/src/nativewindow/classes/com/jogamp/nativewindow/impl/RecursiveToolkitLock.java
+++ b/src/nativewindow/classes/com/jogamp/nativewindow/impl/RecursiveToolkitLock.java
@@ -34,110 +34,144 @@ import javax.media.nativewindow.*;
 // Reentrance locking toolkit
 // 
 public class RecursiveToolkitLock {
-    private Thread owner = null;
-    private int recursionCount = 0;
-    private Exception lockedStack = null;
-    private static final long timeout = 5000;  // maximum wait 5s
-    // private static final long timeout = 300000;  // maximum wait 300s
+    static class SyncData {
+        Thread owner = null;
+        int recursionCount = 0;
+        Exception lockedStack = null;
+    }
+    private SyncData sdata = new SyncData(); // synchronized (flow/mem)  mutable access
+
+    private long timeout;
+    private static final long defaultTimeout = 5000;  // default maximum wait 5s
+    // private static final long defaultTimeout = 10000;  // default maximum wait 10s
+    // private static final long defaultTimeout = 300000;  // default maximum wait 300s / 5min
     private static final boolean TRACE_LOCK = Debug.debug("TraceLock");
 
-    public Exception getLockedStack() {
-        return lockedStack;
+    public RecursiveToolkitLock() {
+        this.timeout = defaultTimeout;
     }
 
-    public Thread getOwner() {
-        return owner;
+    public RecursiveToolkitLock(long timeout) {
+        this.timeout = timeout;
     }
 
-    public boolean isOwner() {
-        return isOwner(Thread.currentThread());
+    public final Exception getLockedStack() {
+        synchronized(sdata) {
+            return sdata.lockedStack;
+        }
     }
 
-    public synchronized boolean isOwner(Thread thread) {
-        return owner == thread ;
+    public final Thread getOwner() {
+        synchronized(sdata) {
+            return sdata.owner;
+        }
     }
 
-    public synchronized boolean isLocked() {
-        return null != owner;
+    public final boolean isOwner() {
+        return isOwner(Thread.currentThread());
     }
 
-    public synchronized boolean isLockedByOtherThread() {
-        return null != owner && Thread.currentThread() != owner ;
+    public final boolean isOwner(Thread thread) {
+        synchronized(sdata) {
+            return sdata.owner == thread ;
+        }
     }
 
-    public synchronized int getRecursionCount() {
-        return recursionCount;
+    public final boolean isLocked() {
+        synchronized(sdata) {
+            return null != sdata.owner;
+        }
     }
 
-    public synchronized void validateLocked() {
-        if ( !isLocked() ) {
-            throw new RuntimeException(Thread.currentThread()+": Not locked");
+    public final boolean isLockedByOtherThread() {
+        synchronized(sdata) {
+            return null != sdata.owner && Thread.currentThread() != sdata.owner ;
         }
-        if ( !isOwner() ) {
-            getLockedStack().printStackTrace();
-            throw new RuntimeException(Thread.currentThread()+": Not owner, owner is "+owner);
+    }
+
+    public final int getRecursionCount() {
+        synchronized(sdata) {
+            return sdata.recursionCount;
         }
     }
 
-    /** Recursive and blocking lockSurface() implementation */
-    public synchronized void lock() {
-        Thread cur = Thread.currentThread();
-        if(TRACE_LOCK) {
-            System.out.println("... LOCK 0 ["+this+"], recursions "+recursionCount+", "+cur);
+    public final void validateLocked() {
+        synchronized(sdata) {
+            if ( null == sdata.owner ) {
+                throw new RuntimeException(Thread.currentThread()+": Not locked");
+            }
+            if ( Thread.currentThread() != sdata.owner ) {
+                getLockedStack().printStackTrace();
+                throw new RuntimeException(Thread.currentThread()+": Not owner, owner is "+sdata.owner);
+            }
         }
-        if (owner == cur) {
-            ++recursionCount;
+    }
+
+    /** Recursive and blocking lockSurface() implementation */
+    public final void lock() {
+        synchronized(sdata) {
+            Thread cur = Thread.currentThread();
             if(TRACE_LOCK) {
-                System.out.println("+++ LOCK 1 ["+this+"], recursions "+recursionCount+", "+cur);
+                System.out.println("... LOCK 0 ["+this+"], recursions "+sdata.recursionCount+", "+cur);
+            }
+            if (sdata.owner == cur) {
+                ++sdata.recursionCount;
+                if(TRACE_LOCK) {
+                    System.out.println("+++ LOCK 1 ["+this+"], recursions "+sdata.recursionCount+", "+cur);
+                }
+                return;
             }
-            return;
-        }
 
-        long ts = System.currentTimeMillis();
-        while (owner != null && (System.currentTimeMillis()-ts) < timeout) {
-            try {
-                wait(timeout);
-            } catch (InterruptedException e) {
-                throw new RuntimeException(e);
+            long ts = System.currentTimeMillis();
+            while (sdata.owner != null && (System.currentTimeMillis()-ts) < timeout) {
+                try {
+                    sdata.wait(timeout);
+                } catch (InterruptedException e) {
+                    throw new RuntimeException(e);
+                }
             }
+            if(sdata.owner != null) {
+                sdata.lockedStack.printStackTrace();
+                throw new RuntimeException("Waited "+timeout+"ms for: "+sdata.owner+" - "+cur+", with recursionCount "+sdata.recursionCount+", lock: "+this);
+            }
+            if(TRACE_LOCK) {
+                System.out.println("+++ LOCK X ["+this+"], recursions "+sdata.recursionCount+", "+cur);
+            }
+            sdata.owner = cur;
+            sdata.lockedStack = new Exception("Previously locked by "+sdata.owner+", lock: "+this);
         }
-        if(owner != null) {
-            lockedStack.printStackTrace();
-            throw new RuntimeException("Waited "+timeout+"ms for: "+owner+" - "+cur+", with recursionCount "+recursionCount+", lock: "+this);
-        }
-        if(TRACE_LOCK) {
-            System.out.println("+++ LOCK X ["+this+"], recursions "+recursionCount+", "+cur);
-        }
-        owner = cur;
-        lockedStack = new Exception("Previously locked by "+owner+", lock: "+this);
     }
     
 
     /** Recursive and unblocking unlockSurface() implementation */
-    public synchronized void unlock() {
+    public final void unlock() {
         unlock(null);
     }
 
     /** Recursive and unblocking unlockSurface() implementation */
-    public synchronized void unlock(Runnable taskAfterUnlockBeforeNotify) {
-        validateLocked();
-
-        if (recursionCount > 0) {
-            --recursionCount;
+    public final void unlock(Runnable taskAfterUnlockBeforeNotify) {
+        synchronized(sdata) {
+            validateLocked();
+
+            if (sdata.recursionCount > 0) {
+                --sdata.recursionCount;
+                if(TRACE_LOCK) {
+                    System.out.println("--- LOCK 1 ["+this+"], recursions "+sdata.recursionCount+", "+Thread.currentThread());
+                }
+                return;
+            }
+            sdata.owner = null;
+            sdata.lockedStack = null;
+            if(null!=taskAfterUnlockBeforeNotify) {
+                taskAfterUnlockBeforeNotify.run();
+            }
             if(TRACE_LOCK) {
-                System.out.println("--- LOCK 1 ["+this+"], recursions "+recursionCount+", "+Thread.currentThread());
+                System.out.println("--- LOCK X ["+this+"], recursions "+sdata.recursionCount+", "+Thread.currentThread());
             }
-            return;
-        }
-        owner = null;
-        lockedStack = null;
-        if(null!=taskAfterUnlockBeforeNotify) {
-            taskAfterUnlockBeforeNotify.run();
-        }
-        if(TRACE_LOCK) {
-            System.out.println("--- LOCK X ["+this+"], recursions "+recursionCount+", "+Thread.currentThread());
+            // Assuming notify() implementation weaks up the longest waiting thread, to avoid starvation. 
+            // Otherwise we would need to have a Thread queue implemented, using sleep(timeout) and interrupt.
+            sdata.notify();
         }
-        notifyAll();
     }
 }
 
diff --git a/src/newt/classes/com/jogamp/newt/impl/WindowImpl.java b/src/newt/classes/com/jogamp/newt/impl/WindowImpl.java
index 0e9114145..72c33f596 100644
--- a/src/newt/classes/com/jogamp/newt/impl/WindowImpl.java
+++ b/src/newt/classes/com/jogamp/newt/impl/WindowImpl.java
@@ -202,7 +202,7 @@ public abstract class WindowImpl implements Window, NEWTEventConsumer
             System.err.println("Window.createNative() START ("+getThreadName()+", "+this+")");
         }
         if( null != parentWindow && 
-            NativeWindow.LOCK_SURFACE_NOT_READY >= parentWindow.lockSurface() ) {
+            NativeSurface.LOCK_SURFACE_NOT_READY >= parentWindow.lockSurface() ) {
                 throw new NativeWindowException("Parent surface lock: not ready: "+parentWindow);
         }
         try {
@@ -236,26 +236,24 @@ public abstract class WindowImpl implements Window, NEWTEventConsumer
     private static long getNativeWindowHandle(NativeWindow nativeWindow) {
         long handle = 0;
         if(null!=nativeWindow) {
-            boolean locked=false;
-            try {
-                if( NativeWindow.LOCK_SURFACE_NOT_READY < nativeWindow.lockSurface() ) {
-                    locked=true;
+            boolean wasLocked = false;
+            if( NativeSurface.LOCK_SURFACE_NOT_READY < nativeWindow.lockSurface() ) {
+                wasLocked = true;
+                try {
                     handle = nativeWindow.getWindowHandle();
                     if(0==handle) {
                         throw new NativeWindowException("Parent native window handle is NULL, after succesful locking: "+nativeWindow);
                     }
-                }
-            } catch (NativeWindowException nwe) {
-                if(DEBUG_IMPLEMENTATION) {
-                    System.err.println("Window.getNativeWindowHandle: not successful yet: "+nwe);
-                }
-            } finally {
-                if(locked) {
+                } catch (NativeWindowException nwe) {
+                    if(DEBUG_IMPLEMENTATION) {
+                        System.err.println("Window.getNativeWindowHandle: not successful yet: "+nwe);
+                    }
+                } finally {
                     nativeWindow.unlockSurface();
                 }
             }
             if(DEBUG_IMPLEMENTATION) {
-                System.err.println("Window.getNativeWindowHandle: locked "+locked+", "+nativeWindow);
+                System.err.println("Window.getNativeWindowHandle: locked "+wasLocked+", "+nativeWindow);
             }
         }
         return handle;
@@ -809,7 +807,7 @@ public abstract class WindowImpl implements Window, NEWTEventConsumer
                     NativeWindow parentWindowLocked = null;
                     if( null != parentWindow ) {
                         parentWindowLocked = parentWindow;
-                        if(NativeWindow.LOCK_SURFACE_NOT_READY >= parentWindowLocked.lockSurface() ) {
+                        if(NativeSurface.LOCK_SURFACE_NOT_READY >= parentWindowLocked.lockSurface() ) {
                             throw new NativeWindowException("Parent surface lock: not ready: "+parentWindow);
                         }
                     }
diff --git a/src/newt/classes/com/jogamp/newt/opengl/GLWindow.java b/src/newt/classes/com/jogamp/newt/opengl/GLWindow.java
index a7104bf1a..d39e0e29b 100644
--- a/src/newt/classes/com/jogamp/newt/opengl/GLWindow.java
+++ b/src/newt/classes/com/jogamp/newt/opengl/GLWindow.java
@@ -456,11 +456,12 @@ public class GLWindow implements GLAutoDrawable, Window {
             if(forceReshape) {
                 sendReshape = true;
             }
-            lockSurface();
-            try{
-                helper.invokeGL(drawable, context, displayAction, initAction);
-            } finally {
-                unlockSurface();
+            if( NativeSurface.LOCK_SURFACE_NOT_READY < lockSurface() ) {
+                try{
+                    helper.invokeGL(drawable, context, displayAction, initAction);
+                } finally {
+                    unlockSurface();
+                }
             }
         }
     }