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	/*
	* Copyright (c) 2002, 2013, 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 arbitrary 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);
	}
	}

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