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/* * Copyright (c) 2002, 2008, 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.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */   package sun.misc; import java.util.Vector;import java.io.FileWriter;import java.io.File;import java.io.OutputStreamWriter;import java.io.Writer; /** * This class is intended to be a central place for the jdk to * log timing events of interest.  There is pre-defined event * of startTime, as well as a general * mechanism of setting aribtrary times in an array. * All unreserved times in the array can be used by callers * in application-defined situations.  The caller is responsible * for setting and getting all times and for doing whatever * analysis is interesting; this class is merely a central container * for those timing values. * Note that, due to the variables in this class being static, * use of particular time values by multiple applets will cause * confusing results.  For example, if plugin runs two applets * simultaneously, the initTime for those applets will collide * and the results may be undefined. * <P> * To automatically track startup performance in an app or applet, * use the command-line parameter sun.perflog as follows:<BR> *     -Dsun.perflog[=file:<filename>] * <BR> * where simply using the parameter with no value will enable output * to the console and a value of "file:<filename>" will cause * that given filename to be created and used for all output. * <P> * By default, times are measured using System.currentTimeMillis().  To use * System.nanoTime() instead, add the command-line parameter:<BR>       -Dsun.perflog.nano=true * <BR> * <P> * <B>Warning: Use at your own risk!</B> * This class is intended for internal testing * purposes only and may be removed at any time.  More * permanent monitoring and profiling APIs are expected to be * developed for future releases and this class will cease to * exist once those APIs are in place. * @author Chet Haase */public class PerformanceLogger {     // Timing values of global interest    private static final int START_INDEX    = 0;    // VM start    private static final int LAST_RESERVED  = START_INDEX;     private static boolean perfLoggingOn = false;    private static boolean useNanoTime = false;    private static Vector<TimeData> times;    private static String logFileName = null;    private static Writer logWriter = null;    private static long baseTime;     static {        String perfLoggingProp =            java.security.AccessController.doPrivileged(            new sun.security.action.GetPropertyAction("sun.perflog"));        if (perfLoggingProp != null) {            perfLoggingOn = true;             // Check if we should use nanoTime            String perfNanoProp =                java.security.AccessController.doPrivileged(                new sun.security.action.GetPropertyAction("sun.perflog.nano"));            if (perfNanoProp != null) {                useNanoTime = true;            }             // Now, figure out what the user wants to do with the data            if (perfLoggingProp.regionMatches(true, 0, "file:", 0, 5)) {                logFileName = perfLoggingProp.substring(5);            }            if (logFileName != null) {                if (logWriter == null) {                    java.security.AccessController.doPrivileged(                    new java.security.PrivilegedAction<Void>() {                        public Void run() {                            try {                                File logFile = new File(logFileName);                                logFile.createNewFile();                                logWriter = new FileWriter(logFile);                            } catch (Exception e) {                                System.out.println(e + ": Creating logfile " +                                                   logFileName +                                                   ".  Log to console");                            }                            return null;                        }                    });                }            }            if (logWriter == null) {                logWriter = new OutputStreamWriter(System.out);            }        }        times = new Vector<TimeData>(10);        // Reserve predefined slots        for (int i = 0; i <= LAST_RESERVED; ++i) {            times.add(new TimeData("Time " + i + " not set", 0));        }    }     /**     * Returns status of whether logging is enabled or not.  This is     * provided as a convenience method so that users do not have to     * perform the same GetPropertyAction check as above to determine whether     * to enable performance logging.     */    public static boolean loggingEnabled() {        return perfLoggingOn;    }      /**     * Internal class used to store time/message data together.     */    static class TimeData {        String message;        long time;         TimeData(String message, long time) {            this.message = message;            this.time = time;        }         String getMessage() {            return message;        }         long getTime() {            return time;        }    }     /**     * Return the current time, in millis or nanos as appropriate     */    private static long getCurrentTime() {        if (useNanoTime) {            return System.nanoTime();        } else {            return System.currentTimeMillis();        }    }     /**     * Sets the start time.  Ideally, this is the earliest time available     * during the startup of a Java applet or application.  This time is     * later used to analyze the difference between the initial startup     * time and other events in the system (such as an applet's init time).     */    public static void setStartTime(String message) {        if (loggingEnabled()) {            long nowTime = getCurrentTime();            setStartTime(message, nowTime);        }    }     /**     * Sets the base time, output can then     * be displayed as offsets from the base time;.     */    public static void setBaseTime(long time) {        if (loggingEnabled()) {            baseTime = time;        }    }     /**     * Sets the start time.     * This version of the method is     * given the time to log, instead of expecting this method to     * get the time itself.  This is done in case the time was     * recorded much earlier than this method was called.     */    public static void setStartTime(String message, long time) {        if (loggingEnabled()) {            times.set(START_INDEX, new TimeData(message, time));        }    }     /**     * Gets the start time, which should be the time when     * the java process started, prior to the VM actually being     * loaded.     */    public static long getStartTime() {        if (loggingEnabled()) {            return times.get(START_INDEX).getTime();        } else {            return 0;        }    }     /**     * Sets the value of a given time and returns the index of the     * slot that that time was stored in.     */    public static int setTime(String message) {        if (loggingEnabled()) {            long nowTime = getCurrentTime();            return setTime(message, nowTime);        } else {            return 0;        }    }     /**     * Sets the value of a given time and returns the index of the     * slot that that time was stored in.     * This version of the method is     * given the time to log, instead of expecting this method to     * get the time itself.  This is done in case the time was     * recorded much earlier than this method was called.     */    public static int setTime(String message, long time) {        if (loggingEnabled()) {            // times is already synchronized, but we need to ensure that            // the size used in times.set() is the same used when returning            // the index of that operation.            synchronized (times) {                times.add(new TimeData(message, time));                return (times.size() - 1);            }        } else {            return 0;        }    }     /**     * Returns time at given index.     */    public static long getTimeAtIndex(int index) {        if (loggingEnabled()) {            return times.get(index).getTime();        } else {            return 0;        }    }     /**     * Returns message at given index.     */    public static String getMessageAtIndex(int index) {        if (loggingEnabled()) {            return times.get(index).getMessage();        } else {            return null;        }    }     /**     * Outputs all data to parameter-specified Writer object     */    public static void outputLog(Writer writer) {        if (loggingEnabled()) {            try {                synchronized(times) {                    for (int i = 0; i < times.size(); ++i) {                        TimeData td = times.get(i);                        if (td != null) {                            writer.write(i + " " + td.getMessage() + ": " +                                         (td.getTime() - baseTime) + "\n");                         }                    }                }                writer.flush();            } catch (Exception e) {                System.out.println(e + ": Writing performance log to " +                                   writer);            }        }    }     /**     * Outputs all data to whatever location the user specified     * via sun.perflog command-line parameter.     */    public static void outputLog() {        outputLog(logWriter);    }}