--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.max.base/src/com/sun/max/program/Trace.java	Sat Dec 17 19:59:18 2011 +0100
@@ -0,0 +1,265 @@
+/*
+ * 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.program;
+
+import java.io.*;
+
+import com.sun.max.annotate.*;
+import com.sun.max.io.*;
+import com.sun.max.program.option.*;
+
+/**
+ * Tracing output for debugging purposes. No performance impact when disabled. Some performance impact when active, even
+ * without output. Possibly significant performance impact when producing a lot of output.
+ */
+public final class Trace {
+
+    private Trace() {
+        // do nothing.
+    }
+
+    private static PrintStream stream;
+
+    public static PrintStream stream() {
+        return stream;
+    }
+
+    public static void setStream(PrintStream stream) {
+        Trace.stream = stream;
+    }
+
+    private static final boolean showThread;
+
+    static {
+        showThread = System.getProperty("max.trace.showThread") != null;
+        final String traceFileName = System.getProperty("max.trace.file");
+        stream = System.out;
+        if (traceFileName != null) {
+            final File traceFile = new File(traceFileName);
+            try {
+                final OutputStream fileStream = new BufferedOutputStream(new FileOutputStream(traceFile));
+                if (System.getProperty("max.trace.noconsole") != null) {
+                    stream = new PrintStream(fileStream);
+                } else {
+                    stream = new PrintStream(new MultiOutputStream(fileStream, System.out));
+                }
+            } catch (IOException ioException) {
+                System.err.println("Could not open file for trace output: " + traceFile.getAbsolutePath());
+            }
+        }
+    }
+
+    /**
+     * Static master switch. Set by source code editing only (for now).
+     *
+     * Set '_enabled' to 'true' to enable tracing output, according to your other trace-related settings.
+     *
+     * Set '_enabled' to 'false' to prevent any tracing. All tracing routines will thus become dead code. The optimizing
+     * compiler should then be able to eliminate the runtime overhead.
+     */
+    private static final boolean ENABLED = true;
+
+    public static void addTo(OptionSet options) {
+        options.addOption(new Option<Integer>("trace", 0, OptionTypes.INT_TYPE, "Sets tracing level.") {
+            @Override
+            public void setValue(Integer value) {
+                super.setValue(value);
+                level = value;
+            }
+        });
+    }
+
+    /**
+     * Dynamically sets tracing level, causing trace commands at this or lower levels to produce output.
+     */
+    public static void on(int newLevel) {
+        assert newLevel >= 0;
+        level = newLevel;
+    }
+
+    /**
+     * Dynamically turns tracing on for all levels.
+     */
+    public static void on() {
+        on(Integer.MAX_VALUE);
+    }
+
+    @RESET
+    private static long count;
+
+    /**
+     * The threshold of trace calls before traces are actually sent to the trace stream.
+     *
+     * This field can be updated by the inspector.
+     */
+    @RESET
+    @INSPECTED
+    private static long threshold;
+
+    /**
+     * The current trace level.
+     *
+     * This field can be updated by the inspector.
+     */
+    @RESET
+    @INSPECTED
+    private static int level;
+
+    /**
+     * Dynamically sets the current tracing level to the greater of the current level or the specified new level.
+     */
+    public static void atLeast(int l) {
+        if (l > level) {
+            level = l;
+        }
+    }
+
+    /**
+     * Dynamically turns tracing off by setting current level to zero.
+     */
+    public static void off() {
+        level = 0;
+    }
+
+    /**
+     * @return current tracing level, which must equal or exceed the level specified by trace commands for output to be produced.
+     */
+    public static int level() {
+        return level;
+    }
+
+    /**
+     * Does the current tracing level equal or exceed the specified level.
+     */
+    public static boolean hasLevel(int requiredLevel) {
+        count++;
+        return level >= requiredLevel && count >= threshold;
+    }
+
+    private static final int MAX_INDENTATION = 10;
+
+    @RESET
+    private static int indentation;
+
+    private static void printInt(int n) {
+        if (n < 10) {
+            stream.write(((char) n) + '0');
+        } else {
+            final int m = n / 10;
+            printInt(m);
+            printInt(n - (m * 10));
+        }
+    }
+
+    /**
+     * This should not cause allocation/GC.
+     */
+    private static void printPrefix(int requiredLevel) {
+        if (showThread) {
+            stream.print(Thread.currentThread().getName() + " <Trace");
+        } else {
+            stream.print("<Trace ");
+        }
+        printInt(requiredLevel);
+        stream.print("> ");
+        for (int i = 0; i < indentation; i++) {
+            stream.print(" ");
+        }
+    }
+
+    /**
+     * Prints a newline on trace output if tracing is globally enabled and current tracing level is at least the level required.
+     */
+    public static void line(int requiredLevel) {
+        if (ENABLED) {
+            if (hasLevel(requiredLevel)) {
+                stream.println();
+                stream.flush();
+            }
+        }
+    }
+
+    /**
+     * Prints a line of trace output if tracing is globally enabled and if current tracing level is at least the level required.
+     */
+    public static void line(int requiredLevel, Object message) {
+        if (ENABLED) {
+            if (hasLevel(requiredLevel)) {
+                printPrefix(requiredLevel);
+                stream.println(message);
+                stream.flush();
+            }
+        }
+    }
+
+    /**
+     * Prints a "BEGIN" line of trace output if tracing is globally enabled and if current tracing level is at least the level required; increases indentation.
+     */
+    public static void begin(int requiredLevel, Object message) {
+        if (ENABLED) {
+            if (hasLevel(requiredLevel)) {
+                printPrefix(requiredLevel);
+                stream.print("BEGIN: ");
+                stream.println(message);
+                stream.flush();
+                indentation++;
+            }
+        }
+    }
+
+    /**
+     * Prints an "END" line of trace output if tracing is globally enabled and if current tracing level is at least the level required; decreases indentation.
+     */
+    public static void end(int requiredLevel, Object message) {
+        end(requiredLevel, message, 0);
+    }
+
+    /**
+     * Prints an "END" line of trace output if tracing is globally enabled and if current tracing level is at least the level required; decreases indentation;
+     * appends a timing message, expressed in milliseconds, if a non-zero starting time is supplied.
+     * @param requiredLevel
+     * @param message
+     * @param startTimeMillis a starting time, output from {@link System#currentTimeMillis()}; no timing message appears if zero.
+     */
+    public static void end(int requiredLevel, Object message, long startTimeMillis) {
+        if (ENABLED) {
+            if (hasLevel(requiredLevel)) {
+                final long endTimeMillis = System.currentTimeMillis();
+                indentation--;
+                // It's quite possible for indentation to go negative in a multithreaded environment
+                //assert _indentation >= 0;
+                printPrefix(requiredLevel);
+                stream.print("END:   ");
+                if (startTimeMillis > 0) {
+                    stream.print(message);
+                    stream.print("  (");
+                    stream.print(endTimeMillis - startTimeMillis);
+                    stream.println("ms)");
+                } else {
+                    stream.println(message);
+                    stream.flush();
+                }
+            }
+        }
+    }
+}