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/* * Copyright (c) 2005, 2006, 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.jstack; import java.lang.reflect.Method;import java.lang.reflect.Constructor;import java.io.IOException;import java.io.InputStream; import com.sun.tools.attach.VirtualMachine;import com.sun.tools.attach.AttachNotSupportedException;import sun.tools.attach.HotSpotVirtualMachine; /* * This class is the main class for the JStack utility. It parses its arguments * and decides if the command should be executed by the SA JStack tool or by * obtained the thread dump from a target process using the VM attach mechanism */public class JStack {    public static void main(String[] args) throws Exception {        if (args.length == 0) {            usage(); // no arguments        }         boolean useSA = false;        boolean mixed = false;        boolean locks = false;         // Parse the options (arguments starting with "-" )        int optionCount = 0;        while (optionCount < args.length) {            String arg = args[optionCount];            if (!arg.startsWith("-")) {                break;            }            if (arg.equals("-F")) {                useSA = true;            } else {                if (arg.equals("-m")) {                    mixed = true;                } else {                    if (arg.equals("-l")) {                       locks = true;                    } else {                        usage();                    }                }            }            optionCount++;        }         // mixed stack implies SA tool        if (mixed) {            useSA = true;        }         // Next we check the parameter count. If there are two parameters        // we assume core file and executable so we use SA.        int paramCount = args.length - optionCount;        if (paramCount == 0 || paramCount > 2) {            usage();        }        if (paramCount == 2) {            useSA = true;        } else {            // If we can't parse it as a pid then it must be debug server            if (!args[optionCount].matches("[0-9]+")) {                useSA = true;            }        }         // now execute using the SA JStack tool or the built-in thread dumper        if (useSA) {            // parameters (<pid> or <exe> <core>            String params[] = new String[paramCount];            for (int i=optionCount; i<args.length; i++ ){                params[i-optionCount] = args[i];            }            runJStackTool(mixed, locks, params);        } else {            // pass -l to thread dump operation to get extra lock info            String pid = args[optionCount];            String params[];            if (locks) {                params = new String[] { "-l" };            } else {                params = new String[0];            }            runThreadDump(pid, params);        }    }      // SA JStack tool    private static void runJStackTool(boolean mixed, boolean locks, String args[]) throws Exception {        Class<?> cl = loadSAClass();        if (cl == null) {            usage();            // SA not available        }         // JStack tool also takes -m and -l arguments        if (mixed) {            args = prepend("-m", args);        }        if (locks) {            args = prepend("-l", args);        }         Class[] argTypes = { String[].class };        Method m = cl.getDeclaredMethod("main", argTypes);         Object[] invokeArgs = { args };        m.invoke(null, invokeArgs);    }     // Returns sun.jvm.hotspot.tools.JStack if available, otherwise null.    private static Class loadSAClass() {        //        // Attempt to load JStack class - we specify the system class        // 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("sun.jvm.hotspot.tools.JStack", true,                                 ClassLoader.getSystemClassLoader());        } catch (Exception x)  { }        return null;    }     // Attach to pid and perform a thread dump    private static void runThreadDump(String pid, String args[]) throws Exception {        VirtualMachine vm = null;        try {            vm = VirtualMachine.attach(pid);        } catch (Exception x) {            String msg = x.getMessage();            if (msg != null) {                System.err.println(pid + ": " + msg);            } else {                x.printStackTrace();            }            if ((x instanceof AttachNotSupportedException) &&                (loadSAClass() != null)) {                System.err.println("The -F option can be used when the target " +                    "process is not responding");            }            System.exit(1);        }         // Cast to HotSpotVirtualMachine as this is implementation specific        // method.        InputStream in = ((HotSpotVirtualMachine)vm).remoteDataDump((Object[])args);         // 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();    }     // return a new string array with arg as the first element    private static String[] prepend(String arg, String args[]) {        String[] newargs = new String[args.length+1];        newargs[0] = arg;        System.arraycopy(args, 0, newargs, 1, args.length);        return newargs;    }     // print usage message    private static void usage() {        System.out.println("Usage:");        System.out.println("    jstack [-l] <pid>");        System.out.println("        (to connect to running process)");         if (loadSAClass() != null) {            System.out.println("    jstack -F [-m] [-l] <pid>");            System.out.println("        (to connect to a hung process)");            System.out.println("    jstack [-m] [-l] <executable> <core>");            System.out.println("        (to connect to a core file)");            System.out.println("    jstack [-m] [-l] [server_id@]<remote server IP or hostname>");            System.out.println("        (to connect to a remote debug server)");        }         System.out.println("");        System.out.println("Options:");         if (loadSAClass() != null) {            System.out.println("    -F  to force a thread dump. Use when jstack <pid> does not respond" +                " (process is hung)");            System.out.println("    -m  to print both java and native frames (mixed mode)");        }         System.out.println("    -l  long listing. Prints additional information about locks");        System.out.println("    -h or -help to print this help message");        System.exit(1);    }}