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	/*
	* Copyright (c) 2006, 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.tools.jinfo;

	import java.lang.reflect.Method;
	import java.io.IOException;
	import java.io.InputStream;

	import com.sun.tools.attach.VirtualMachine;
	import sun.tools.attach.HotSpotVirtualMachine;

	/*
	* This class is the main class for the JInfo utility. It parses its arguments
	* and decides if the command should be satisfied using the VM attach mechanism
	* or an SA tool. At this time the only option that uses the VM attach
	* mechanism is the -flag option to set or print a command line option of a
	* running application. All other options are mapped to SA tools.
	*/
	public class JInfo {

	public static void main(String[] args) throws Exception {
	if (args.length == 0) {
	usage(1); // no arguments
	}

	boolean useSA = true;
	String arg1 = args[0];
	if (arg1.startsWith("-")) {
	if (arg1.equals("-flags") \|\|
	arg1.equals("-sysprops")) {
	// SA JInfo needs <pid> or <server> or
	// (<executable> and <code file>). So, total
	// argument count including option has to 2 or 3.
	if (args.length != 2 && args.length != 3) {
	usage(1);
	}
	} else if (arg1.equals("-flag")) {
	// do not use SA, use attach-on-demand
	useSA = false;
	} else {
	// unknown option or -h or -help, print help
	int exit;
	if (arg1.equals("-help") \|\| arg1.equals("-h")) {
	exit = 0;
	} else {
	exit = 1;
	}
	usage(exit);
	}
	}

	if (useSA) {
	runTool(args);
	} else {
	if (args.length == 3) {
	String pid = args[2];
	String option = args[1];
	flag(pid, option);
	} else {
	int exit;
	if (arg1.equals("-help") \|\| arg1.equals("-h")) {
	exit = 0;
	} else {
	exit = 1;
	}
	usage(exit);
	}
	}
	}

	// Invoke SA tool with the given arguments
	private static void runTool(String args[]) throws Exception {
	String tool = "sun.jvm.hotspot.tools.JInfo";
	// Tool not available on this platform.
	Class<?> c = loadClass(tool);
	if (c == null) {
	usage(1);
	}

	// invoke the main method with the arguments
	Class[] argTypes = { String[].class } ;
	Method m = c.getDeclaredMethod("main", argTypes);

	Object[] invokeArgs = { args };
	m.invoke(null, invokeArgs);
	}

	// loads the given class using the system class loader
	private static Class<?> loadClass(String name) {
	//
	// We specify the system clas loader so as to cater for development
	// environments where this class is on the boot class path but sa-jdi.jar
	// is on the system class path. Once the JDK is deployed then both
	// tools.jar and sa-jdi.jar are on the system class path.
	//
	try {
	return Class.forName(name, true,
	ClassLoader.getSystemClassLoader());
	} catch (Exception x) { }
	return null;
	}

	private static void flag(String pid, String option) throws IOException {
	VirtualMachine vm = attach(pid);
	String flag;
	InputStream in;
	int index = option.indexOf('=');
	if (index != -1) {
	flag = option.substring(0, index);
	String value = option.substring(index + 1);
	in = ((HotSpotVirtualMachine)vm).setFlag(flag, value);
	} else {
	char c = option.charAt(0);
	switch (c) {
	case '+':
	flag = option.substring(1);
	in = ((HotSpotVirtualMachine)vm).setFlag(flag, "1");
	break;
	case '-':
	flag = option.substring(1);
	in = ((HotSpotVirtualMachine)vm).setFlag(flag, "0");
	break;
	default:
	flag = option;
	in = ((HotSpotVirtualMachine)vm).printFlag(flag);
	break;
	}
	}

	drain(vm, in);
	}

	// Attach to <pid>, exiting if we fail to attach
	private static VirtualMachine attach(String pid) {
	try {
	return VirtualMachine.attach(pid);
	} catch (Exception x) {
	String msg = x.getMessage();
	if (msg != null) {
	System.err.println(pid + ": " + msg);
	} else {
	x.printStackTrace();
	}
	System.exit(1);
	return null; // keep compiler happy
	}
	}

	// Read the stream from the target VM until EOF, then detach
	private static void drain(VirtualMachine vm, InputStream in) throws IOException {
	// read to EOF and just print output
	byte b[] = new byte[256];
	int n;
	do {
	n = in.read(b);
	if (n > 0) {
	String s = new String(b, 0, n, "UTF-8");
	System.out.print(s);
	}
	} while (n > 0);
	in.close();
	vm.detach();
	}


	// print usage message
	private static void usage(int exit) {

	Class<?> c = loadClass("sun.jvm.hotspot.tools.JInfo");
	boolean usageSA = (c != null);

	System.err.println("Usage:");
	if (usageSA) {
	System.err.println(" jinfo [option] <pid>");
	System.err.println(" (to connect to running process)");
	System.err.println(" jinfo [option] <executable <core>");
	System.err.println(" (to connect to a core file)");
	System.err.println(" jinfo [option] [server_id@]<remote server IP or hostname>");
	System.err.println(" (to connect to remote debug server)");
	System.err.println("");
	System.err.println("where <option> is one of:");
	System.err.println(" -flag <name> to print the value of the named VM flag");
	System.err.println(" -flag [+\|-]<name> to enable or disable the named VM flag");
	System.err.println(" -flag <name>=<value> to set the named VM flag to the given value");
	System.err.println(" -flags to print VM flags");
	System.err.println(" -sysprops to print Java system properties");
	System.err.println(" <no option> to print both of the above");
	System.err.println(" -h \| -help to print this help message");
	} else {
	System.err.println(" jinfo <option> <pid>");
	System.err.println(" (to connect to a running process)");
	System.err.println("");
	System.err.println("where <option> is one of:");
	System.err.println(" -flag <name> to print the value of the named VM flag");
	System.err.println(" -flag [+\|-]<name> to enable or disable the named VM flag");
	System.err.println(" -flag <name>=<value> to set the named VM flag to the given value");
	System.err.println(" -h \| -help to print this help message");
	}

	System.exit(exit);
	}
	}

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