--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.max.base/src/com/sun/max/profile/Clock.java	Sat Dec 17 19:59:18 2011 +0100
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2007, 2011, Oracle and/or its affiliates. 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.
+ *
+ * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.sun.max.profile;
+
+/**
+ * The {@code Clock} class represents a clock source that has a continuously increasing tick
+ * count. A clock can be used to produce a relative timing between events by comparing the
+ * number of ticks between events. This can be used to implement time-based profiling
+ * by using a clock based on the system time.
+ */
+public abstract class Clock {
+
+    public abstract long getTicks();
+
+    /**
+     * Gets the resolution of this clock as the number of {@linkplain #getTicks() ticks} per second.
+     * @return the resolution of the clock
+     */
+    public abstract long getHZ();
+
+    public static final Clock SYSTEM_NANOSECONDS = new SystemNS();
+    public static final Clock SYSTEM_MILLISECONDS = new SystemMS();
+
+    private static class SystemMS extends Clock {
+        @Override
+        public long getTicks() {
+            return System.currentTimeMillis();
+        }
+        @Override
+        public long getHZ() {
+            return 1000;
+        }
+    }
+
+    private static class SystemNS extends Clock {
+        @Override
+        public long getTicks() {
+            return System.nanoTime();
+        }
+        @Override
+        public long getHZ() {
+            return 1000000000;
+        }
+    }
+
+    public static int[] sampleDeltas(Clock clock, int numberOfSamples) {
+        final int[] result = new int[numberOfSamples];
+        long sample = clock.getTicks();
+        for (int i = 0; i < numberOfSamples; i++) {
+            final long newSample = clock.getTicks();
+            result[i] = (int) (newSample - sample);
+            sample = newSample;
+        }
+        return result;
+    }
+
+    public static void sample5(Clock clock, long[] samples) {
+        final long sample0 = clock.getTicks();
+        final long sample1 = clock.getTicks();
+        final long sample2 = clock.getTicks();
+        final long sample3 = clock.getTicks();
+        final long sample4 = clock.getTicks();
+        samples[0] = sample0;
+        samples[1] = sample1;
+        samples[2] = sample2;
+        samples[3] = sample3;
+        samples[4] = sample4;
+    }
+}