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diff --git a/src/javax/media/j3d/J3dClock.java b/src/javax/media/j3d/J3dClock.java
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+++ b/src/javax/media/j3d/J3dClock.java
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+/*
+ * Copyright 2005-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+package javax.media.j3d;
+
+/**
+ * Utility class to provide a more accurate replacement for
+ * System.currentTimeMillis().
+ */
+class J3dClock {
+
+    // Issue 543 - Flag to indicate whether clock skews are taken in account
+    // and corrected. false by default. Set by the "j3d.adjustClockSkew" property.
+    private static boolean skewAdjustedClock = false;
+
+    private static long deltaTime;
+    private static final long nsecPerMsec = 1000000;
+
+    /**
+     * Private constructor, since no instance should ever be created.
+     */
+    private J3dClock() {
+    }
+
+    /**
+     * Returns the current time in milliseconds. This is a more
+     * accurate version of System.currentTimeMillis and should be used in
+     * its place.
+     *
+     * @return the current time in milliseconds.
+     */
+    static long currentTimeMillis() {
+        if (!skewAdjustedClock) {
+            return (System.nanoTime() / nsecPerMsec) + deltaTime;
+        } else {
+            // Issue 543 - Adjust for possible clock skew
+            long time = (System.nanoTime() / nsecPerMsec) + deltaTime;
+            long sysTime = System.currentTimeMillis();
+            if (Math.abs(time - sysTime) > 50) {
+                long baseTime, baseTimerValue;
+                synchronized (J3dClock.class) {
+                    baseTime = System.currentTimeMillis();
+                    baseTimerValue = System.nanoTime();
+                }
+                deltaTime = baseTime - (baseTimerValue / nsecPerMsec);
+                time = (System.nanoTime() / nsecPerMsec) + deltaTime;
+            }
+            return time;
+        }
+    }
+
+    static {
+        // Issue 543: get property for clock skew adjustment
+        skewAdjustedClock = MasterControl.getBooleanProperty("j3d.adjustClockSkew",
+                skewAdjustedClock, "clock skew adjustment");
+
+        // Call time methods once without using their values to ensure that
+        // the methods are "warmed up". We need to make sure that the actual
+        // calls that we use take place as close together as possible in time.
+        System.currentTimeMillis();
+        System.nanoTime();
+
+        // Compute deltaTime between System.currentTimeMillis()
+        // and the high-res timer, use a synchronized block to force both calls
+        // to be made before the integer divide
+        long baseTime, baseTimerValue;
+        synchronized (J3dClock.class) {
+            baseTime = System.currentTimeMillis();
+            baseTimerValue = System.nanoTime();
+        }
+        deltaTime = baseTime - (baseTimerValue / nsecPerMsec);
+    }
+}