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	/*
	* Copyright (c) 2003, 2017, 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.management;

	import java.io.BufferedInputStream;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.io.InputStream;
	import java.lang.management.ManagementFactory;
	import java.lang.reflect.InvocationTargetException;
	import java.lang.reflect.Method;
	import java.net.InetAddress;
	import java.net.UnknownHostException;
	import java.text.MessageFormat;
	import java.util.MissingResourceException;
	import java.util.Properties;
	import java.util.ResourceBundle;

	import javax.management.remote.JMXConnectorServer;
	import javax.management.remote.JMXServiceURL;

	import static sun.management.AgentConfigurationError.*;
	import sun.management.jmxremote.ConnectorBootstrap;
	import sun.management.jdp.JdpController;
	import sun.management.jdp.JdpException;
	import sun.misc.VMSupport;

	/**
	* This Agent is started by the VM when -Dcom.sun.management.snmp or
	* -Dcom.sun.management.jmxremote is set. This class will be loaded by the
	* system class loader. Also jmx framework could be started by jcmd
	*/
	public class Agent {
	// management properties

	private static Properties mgmtProps;
	private static ResourceBundle messageRB;
	private static final String CONFIG_FILE =
	"com.sun.management.config.file";
	private static final String SNMP_PORT =
	"com.sun.management.snmp.port";
	private static final String JMXREMOTE =
	"com.sun.management.jmxremote";
	private static final String JMXREMOTE_PORT =
	"com.sun.management.jmxremote.port";
	private static final String RMI_PORT =
	"com.sun.management.jmxremote.rmi.port";
	private static final String ENABLE_THREAD_CONTENTION_MONITORING =
	"com.sun.management.enableThreadContentionMonitoring";
	private static final String LOCAL_CONNECTOR_ADDRESS_PROP =
	"com.sun.management.jmxremote.localConnectorAddress";
	private static final String SNMP_ADAPTOR_BOOTSTRAP_CLASS_NAME =
	"sun.management.snmp.AdaptorBootstrap";

	private static final String JDP_DEFAULT_ADDRESS = "224.0.23.178";
	private static final int JDP_DEFAULT_PORT = 7095;

	// The only active agent allowed
	private static JMXConnectorServer jmxServer = null;

	// Parse string com.sun.management.prop=xxx,com.sun.management.prop=yyyy
	// and return property set if args is null or empty
	// return empty property set
	private static Properties parseString(String args) {
	Properties argProps = new Properties();
	if (args != null && !args.trim().equals("")) {
	for (String option : args.split(",")) {
	String s[] = option.split("=", 2);
	String name = s[0].trim();
	String value = (s.length > 1) ? s[1].trim() : "";

	if (!name.startsWith("com.sun.management.")) {
	error(INVALID_OPTION, name);
	}

	argProps.setProperty(name, value);
	}
	}

	return argProps;
	}

	// invoked by -javaagent or -Dcom.sun.management.agent.class
	public static void premain(String args) throws Exception {
	agentmain(args);
	}

	// invoked by attach mechanism
	public static void agentmain(String args) throws Exception {
	if (args == null \|\| args.length() == 0) {
	args = JMXREMOTE; // default to local management
	}

	Properties arg_props = parseString(args);

	// Read properties from the config file
	Properties config_props = new Properties();
	String fname = arg_props.getProperty(CONFIG_FILE);
	readConfiguration(fname, config_props);

	// Arguments override config file
	config_props.putAll(arg_props);
	startAgent(config_props);
	}

	// jcmd ManagementAgent.start_local entry point
	// Also called due to command-line via startAgent()
	private static synchronized void startLocalManagementAgent() {
	Properties agentProps = VMSupport.getAgentProperties();

	// start local connector if not started
	if (agentProps.get(LOCAL_CONNECTOR_ADDRESS_PROP) == null) {
	JMXConnectorServer cs = ConnectorBootstrap.startLocalConnectorServer();
	String address = cs.getAddress().toString();
	// Add the local connector address to the agent properties
	agentProps.put(LOCAL_CONNECTOR_ADDRESS_PROP, address);

	try {
	// export the address to the instrumentation buffer
	ConnectorAddressLink.export(address);
	} catch (Exception x) {
	// Connector server started but unable to export address
	// to instrumentation buffer - non-fatal error.
	warning(EXPORT_ADDRESS_FAILED, x.getMessage());
	}
	}
	}

	// jcmd ManagementAgent.start entry point
	// This method starts the remote JMX agent and starts neither
	// the local JMX agent nor the SNMP agent
	// @see #startLocalManagementAgent and also @see #startAgent.
	private static synchronized void startRemoteManagementAgent(String args) throws Exception {
	if (jmxServer != null) {
	throw new RuntimeException(getText(INVALID_STATE, "Agent already started"));
	}

	try {
	Properties argProps = parseString(args);
	Properties configProps = new Properties();

	// Load the management properties from the config file
	// if config file is not specified readConfiguration implicitly
	// reads <java.home>/lib/management/management.properties

	String fname = System.getProperty(CONFIG_FILE);
	readConfiguration(fname, configProps);

	// management properties can be overridden by system properties
	// which take precedence
	Properties sysProps = System.getProperties();
	synchronized (sysProps) {
	configProps.putAll(sysProps);
	}

	// if user specifies config file into command line for either
	// jcmd utilities or attach command it overrides properties set in
	// command line at the time of VM start
	String fnameUser = argProps.getProperty(CONFIG_FILE);
	if (fnameUser != null) {
	readConfiguration(fnameUser, configProps);
	}

	// arguments specified in command line of jcmd utilities
	// override both system properties and one set by config file
	// specified in jcmd command line
	configProps.putAll(argProps);

	// jcmd doesn't allow to change ThreadContentionMonitoring, but user
	// can specify this property inside config file, so enable optional
	// monitoring functionality if this property is set
	final String enableThreadContentionMonitoring =
	configProps.getProperty(ENABLE_THREAD_CONTENTION_MONITORING);

	if (enableThreadContentionMonitoring != null) {
	ManagementFactory.getThreadMXBean().
	setThreadContentionMonitoringEnabled(true);
	}

	String jmxremotePort = configProps.getProperty(JMXREMOTE_PORT);
	if (jmxremotePort != null) {
	jmxServer = ConnectorBootstrap.
	startRemoteConnectorServer(jmxremotePort, configProps);

	startDiscoveryService(configProps);
	} else {
	throw new AgentConfigurationError(INVALID_JMXREMOTE_PORT, "No port specified");
	}
	} catch (AgentConfigurationError err) {
	error(err);
	}
	}

	private static synchronized void stopRemoteManagementAgent() throws Exception {

	JdpController.stopDiscoveryService();

	if (jmxServer != null) {
	ConnectorBootstrap.unexportRegistry();

	// Attempt to stop already stopped agent
	// Don't cause any errors.
	jmxServer.stop();
	jmxServer = null;
	}
	}

	private static void startAgent(Properties props) throws Exception {
	String snmpPort = props.getProperty(SNMP_PORT);
	String jmxremote = props.getProperty(JMXREMOTE);
	String jmxremotePort = props.getProperty(JMXREMOTE_PORT);

	// Enable optional monitoring functionality if requested
	final String enableThreadContentionMonitoring =
	props.getProperty(ENABLE_THREAD_CONTENTION_MONITORING);
	if (enableThreadContentionMonitoring != null) {
	ManagementFactory.getThreadMXBean().
	setThreadContentionMonitoringEnabled(true);
	}

	try {
	if (snmpPort != null) {
	loadSnmpAgent(snmpPort, props);
	}

	/*
	* If the jmxremote.port property is set then we start the
	* RMIConnectorServer for remote M&M.
	*
	* If the jmxremote or jmxremote.port properties are set then
	* we start a RMIConnectorServer for local M&M. The address
	* of this "local" server is exported as a counter to the jstat
	* instrumentation buffer.
	*/
	if (jmxremote != null \|\| jmxremotePort != null) {
	if (jmxremotePort != null) {
	jmxServer = ConnectorBootstrap.
	startRemoteConnectorServer(jmxremotePort, props);
	startDiscoveryService(props);
	}
	startLocalManagementAgent();
	}

	} catch (AgentConfigurationError e) {
	error(e);
	} catch (Exception e) {
	error(e);
	}
	}

	private static void startDiscoveryService(Properties props)
	throws IOException {
	// Start discovery service if requested
	String discoveryPort = props.getProperty("com.sun.management.jdp.port");
	String discoveryAddress = props.getProperty("com.sun.management.jdp.address");
	String discoveryShouldStart = props.getProperty("com.sun.management.jmxremote.autodiscovery");

	// Decide whether we should start autodicovery service.
	// To start autodiscovery following conditions should be met:
	// autodiscovery==true OR (autodicovery==null AND jdp.port != NULL)

	boolean shouldStart = false;
	if (discoveryShouldStart == null){
	shouldStart = (discoveryPort != null);
	}
	else{
	try{
	shouldStart = Boolean.parseBoolean(discoveryShouldStart);
	} catch (NumberFormatException e) {
	throw new AgentConfigurationError("Couldn't parse autodiscovery argument");
	}
	}

	if (shouldStart) {
	// port and address are required arguments and have no default values
	InetAddress address;
	try {
	address = (discoveryAddress == null) ?
	InetAddress.getByName(JDP_DEFAULT_ADDRESS) : InetAddress.getByName(discoveryAddress);
	} catch (UnknownHostException e) {
	throw new AgentConfigurationError("Unable to broadcast to requested address", e);
	}

	int port = JDP_DEFAULT_PORT;
	if (discoveryPort != null) {
	try {
	port = Integer.parseInt(discoveryPort);
	} catch (NumberFormatException e) {
	throw new AgentConfigurationError("Couldn't parse JDP port argument");
	}
	}

	// Rebuilding service URL to broadcast it
	String jmxremotePort = props.getProperty(JMXREMOTE_PORT);
	String rmiPort = props.getProperty(RMI_PORT);

	JMXServiceURL url = jmxServer.getAddress();
	String hostname = url.getHost();

	String jmxUrlStr = (rmiPort != null)
	? String.format(
	"service:jmx:rmi://%s:%s/jndi/rmi://%s:%s/jmxrmi",
	hostname, rmiPort, hostname, jmxremotePort)
	: String.format(
	"service:jmx:rmi:///jndi/rmi://%s:%s/jmxrmi", hostname, jmxremotePort);

	String instanceName = props.getProperty("com.sun.management.jdp.name");

	try{
	JdpController.startDiscoveryService(address, port, instanceName, jmxUrlStr);
	}
	catch(JdpException e){
	throw new AgentConfigurationError("Couldn't start JDP service", e);
	}
	}
	}

	public static Properties loadManagementProperties() {
	Properties props = new Properties();

	// Load the management properties from the config file

	String fname = System.getProperty(CONFIG_FILE);
	readConfiguration(fname, props);

	// management properties can be overridden by system properties
	// which take precedence
	Properties sysProps = System.getProperties();
	synchronized (sysProps) {
	props.putAll(sysProps);
	}

	return props;
	}

	public static synchronized Properties getManagementProperties() {
	if (mgmtProps == null) {
	String configFile = System.getProperty(CONFIG_FILE);
	String snmpPort = System.getProperty(SNMP_PORT);
	String jmxremote = System.getProperty(JMXREMOTE);
	String jmxremotePort = System.getProperty(JMXREMOTE_PORT);

	if (configFile == null && snmpPort == null
	&& jmxremote == null && jmxremotePort == null) {
	// return if out-of-the-management option is not specified
	return null;
	}
	mgmtProps = loadManagementProperties();
	}
	return mgmtProps;
	}

	private static void loadSnmpAgent(String snmpPort, Properties props) {
	try {
	// invoke the following through reflection:
	// AdaptorBootstrap.initialize(snmpPort, props);
	final Class<?> adaptorClass =
	Class.forName(SNMP_ADAPTOR_BOOTSTRAP_CLASS_NAME, true, null);
	final Method initializeMethod =
	adaptorClass.getMethod("initialize",
	String.class, Properties.class);
	initializeMethod.invoke(null, snmpPort, props);
	} catch (ClassNotFoundException \| NoSuchMethodException \| IllegalAccessException x) {
	// snmp runtime doesn't exist - initialization fails
	throw new UnsupportedOperationException("Unsupported management property: " + SNMP_PORT, x);
	} catch (InvocationTargetException x) {
	final Throwable cause = x.getCause();
	if (cause instanceof RuntimeException) {
	throw (RuntimeException) cause;
	} else if (cause instanceof Error) {
	throw (Error) cause;
	}
	// should not happen...
	throw new UnsupportedOperationException("Unsupported management property: " + SNMP_PORT, cause);
	}
	}

	// read config file and initialize the properties
	private static void readConfiguration(String fname, Properties p) {
	if (fname == null) {
	String home = System.getProperty("java.home");
	if (home == null) {
	throw new Error("Can't find java.home ??");
	}
	StringBuffer defaultFileName = new StringBuffer(home);
	defaultFileName.append(File.separator).append("lib");
	defaultFileName.append(File.separator).append("management");
	defaultFileName.append(File.separator).append("management.properties");
	// Set file name
	fname = defaultFileName.toString();
	}
	final File configFile = new File(fname);
	if (!configFile.exists()) {
	error(CONFIG_FILE_NOT_FOUND, fname);
	}

	InputStream in = null;
	try {
	in = new FileInputStream(configFile);
	BufferedInputStream bin = new BufferedInputStream(in);
	p.load(bin);
	} catch (FileNotFoundException e) {
	error(CONFIG_FILE_OPEN_FAILED, e.getMessage());
	} catch (IOException e) {
	error(CONFIG_FILE_OPEN_FAILED, e.getMessage());
	} catch (SecurityException e) {
	error(CONFIG_FILE_ACCESS_DENIED, fname);
	} finally {
	if (in != null) {
	try {
	in.close();
	} catch (IOException e) {
	error(CONFIG_FILE_CLOSE_FAILED, fname);
	}
	}
	}
	}

	public static void startAgent() throws Exception {
	String prop = System.getProperty("com.sun.management.agent.class");

	// -Dcom.sun.management.agent.class not set so read management
	// properties and start agent
	if (prop == null) {
	// initialize management properties
	Properties props = getManagementProperties();
	if (props != null) {
	startAgent(props);
	}
	return;
	}

	// -Dcom.sun.management.agent.class=<agent classname>:<agent args>
	String[] values = prop.split(":");
	if (values.length < 1 \|\| values.length > 2) {
	error(AGENT_CLASS_INVALID, "\"" + prop + "\"");
	}
	String cname = values[0];
	String args = (values.length == 2 ? values[1] : null);

	if (cname == null \|\| cname.length() == 0) {
	error(AGENT_CLASS_INVALID, "\"" + prop + "\"");
	}

	if (cname != null) {
	try {
	// Instantiate the named class.
	// invoke the premain(String args) method
	Class<?> clz = ClassLoader.getSystemClassLoader().loadClass(cname);
	Method premain = clz.getMethod("premain",
	new Class<?>[]{String.class});
	premain.invoke(null, /* static */
	new Object[]{args});
	} catch (ClassNotFoundException ex) {
	error(AGENT_CLASS_NOT_FOUND, "\"" + cname + "\"");
	} catch (NoSuchMethodException ex) {
	error(AGENT_CLASS_PREMAIN_NOT_FOUND, "\"" + cname + "\"");
	} catch (SecurityException ex) {
	error(AGENT_CLASS_ACCESS_DENIED);
	} catch (Exception ex) {
	String msg = (ex.getCause() == null
	? ex.getMessage()
	: ex.getCause().getMessage());
	error(AGENT_CLASS_FAILED, msg);
	}
	}
	}

	public static void error(String key) {
	String keyText = getText(key);
	System.err.print(getText("agent.err.error") + ": " + keyText);
	throw new RuntimeException(keyText);
	}

	public static void error(String key, String message) {
	String keyText = getText(key);
	System.err.print(getText("agent.err.error") + ": " + keyText);
	System.err.println(": " + message);
	throw new RuntimeException(keyText + ": " + message);
	}

	public static void error(Exception e) {
	e.printStackTrace();
	System.err.println(getText(AGENT_EXCEPTION) + ": " + e.toString());
	throw new RuntimeException(e);
	}

	public static void error(AgentConfigurationError e) {
	String keyText = getText(e.getError());
	String[] params = e.getParams();

	System.err.print(getText("agent.err.error") + ": " + keyText);

	if (params != null && params.length != 0) {
	StringBuffer message = new StringBuffer(params[0]);
	for (int i = 1; i < params.length; i++) {
	message.append(" " + params[i]);
	}
	System.err.println(": " + message);
	}
	e.printStackTrace();
	throw new RuntimeException(e);
	}

	public static void warning(String key, String message) {
	System.err.print(getText("agent.err.warning") + ": " + getText(key));
	System.err.println(": " + message);
	}

	private static void initResource() {
	try {
	messageRB =
	ResourceBundle.getBundle("sun.management.resources.agent");
	} catch (MissingResourceException e) {
	throw new Error("Fatal: Resource for management agent is missing");
	}
	}

	public static String getText(String key) {
	if (messageRB == null) {
	initResource();
	}
	try {
	return messageRB.getString(key);
	} catch (MissingResourceException e) {
	return "Missing management agent resource bundle: key = \"" + key + "\"";
	}
	}

	public static String getText(String key, String... args) {
	if (messageRB == null) {
	initResource();
	}
	String format = messageRB.getString(key);
	if (format == null) {
	format = "missing resource key: key = \"" + key + "\", "
	+ "arguments = \"{0}\", \"{1}\", \"{2}\"";
	}
	return MessageFormat.format(format, (Object[]) args);
	}
	}

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