1/*
2 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package sun.tools.jstack;
27
28import java.io.InputStream;
29import java.util.Collection;
30
31import com.sun.tools.attach.VirtualMachine;
32import com.sun.tools.attach.VirtualMachineDescriptor;
33import sun.tools.attach.HotSpotVirtualMachine;
34import sun.tools.common.ProcessArgumentMatcher;
35
36/*
37 * This class is the main class for the JStack utility. It parses its arguments
38 * and decides if the command should be executed by the SA JStack tool or by
39 * obtained the thread dump from a target process using the VM attach mechanism
40 */
41public class JStack {
42
43    public static void main(String[] args) throws Exception {
44        if (args.length == 0) {
45            usage(1); // no arguments
46        }
47
48        checkForUnsupportedOptions(args);
49
50        boolean locks = false;
51
52        // Parse the options (arguments starting with "-" )
53        int optionCount = 0;
54        while (optionCount < args.length) {
55            String arg = args[optionCount];
56            if (!arg.startsWith("-")) {
57                break;
58            }
59            if (arg.equals("-help") || arg.equals("-h")) {
60                usage(0);
61            }
62            else {
63                if (arg.equals("-l")) {
64                    locks = true;
65                } else {
66                    usage(1);
67                }
68            }
69            optionCount++;
70        }
71
72        // Next we check the parameter count.
73        int paramCount = args.length - optionCount;
74        if (paramCount != 1) {
75            usage(1);
76        }
77
78        // pass -l to thread dump operation to get extra lock info
79        String pidArg = args[optionCount];
80        String params[];
81        if (locks) {
82            params = new String[] { "-l" };
83        } else {
84            params = new String[0];
85        }
86        ProcessArgumentMatcher ap = new ProcessArgumentMatcher(pidArg);
87        Collection<String> pids = ap.getVirtualMachinePids(JStack.class);
88
89        if (pids.isEmpty()) {
90            System.err.println("Could not find any processes matching : '" + pidArg + "'");
91            System.exit(1);
92        }
93
94        for (String pid : pids) {
95            if (pids.size() > 1) {
96                System.out.println("Pid:" + pid);
97            }
98            runThreadDump(pid, params);
99        }
100    }
101
102    // Attach to pid and perform a thread dump
103    private static void runThreadDump(String pid, String args[]) throws Exception {
104        VirtualMachine vm = null;
105        try {
106            vm = VirtualMachine.attach(pid);
107        } catch (Exception x) {
108            String msg = x.getMessage();
109            if (msg != null) {
110                System.err.println(pid + ": " + msg);
111            } else {
112                x.printStackTrace();
113            }
114            System.exit(1);
115        }
116
117        // Cast to HotSpotVirtualMachine as this is implementation specific
118        // method.
119        InputStream in = ((HotSpotVirtualMachine)vm).remoteDataDump((Object[])args);
120
121        // read to EOF and just print output
122        byte b[] = new byte[256];
123        int n;
124        do {
125            n = in.read(b);
126            if (n > 0) {
127                String s = new String(b, 0, n, "UTF-8");
128                System.out.print(s);
129            }
130        } while (n > 0);
131        in.close();
132        vm.detach();
133    }
134
135    private static void checkForUnsupportedOptions(String[] args) {
136        // Check arguments for -F, -m, and non-numeric value
137        // and warn the user that SA is not supported anymore
138
139        int paramCount = 0;
140
141        for (String s : args) {
142            if (s.equals("-F")) {
143                SAOptionError("-F option used");
144            }
145
146            if (s.equals("-m")) {
147                SAOptionError("-m option used");
148            }
149
150            if (! s.startsWith("-")) {
151                paramCount += 1;
152            }
153        }
154
155        if (paramCount > 1) {
156            SAOptionError("More than one non-option argument");
157        }
158    }
159
160    private static void SAOptionError(String msg) {
161        System.err.println("Error: " + msg);
162        System.err.println("Cannot connect to core dump or remote debug server. Use jhsdb jstack instead");
163        System.exit(1);
164    }
165
166    // print usage message
167    private static void usage(int exit) {
168        System.err.println("Usage:");
169        System.err.println("    jstack [-l] <pid>");
170        System.err.println("        (to connect to running process)");
171        System.err.println("");
172        System.err.println("Options:");
173        System.err.println("    -l  long listing. Prints additional information about locks");
174        System.err.println("    -h or -help to print this help message");
175        System.exit(exit);
176    }
177}
178