1 /*
2 * Copyright (c) 2005, 2018, 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
26 package sun.tools.jstack;
27
28 import java.io.InputStream;
29 import java.util.Collection;
30
31 import com.sun.tools.attach.VirtualMachine;
32 import com.sun.tools.attach.VirtualMachineDescriptor;
33 import sun.tools.attach.HotSpotVirtualMachine;
34 import 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 */
41 public 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 boolean extended = false;
52
53 // Parse the options (arguments starting with "-" )
54 int optionCount = 0;
55 while (optionCount < args.length) {
56 String arg = args[optionCount];
57 if (!arg.startsWith("-")) {
58 break;
59 }
60 if (arg.equals("-?") ||
61 arg.equals("-h") ||
62 arg.equals("--help") ||
63 // -help: legacy.
64 arg.equals("-help")) {
65 usage(0);
66 }
67 else {
68 if (arg.equals("-l")) {
69 locks = true;
70 } else {
71 if (arg.equals("-e")) {
72 extended = true;
73 } else {
74 usage(1);
75 }
76 }
77 }
78 optionCount++;
79 }
80
81 // Next we check the parameter count.
82 int paramCount = args.length - optionCount;
83 if (paramCount != 1) {
84 usage(1);
85 }
86
87 // pass -l to thread dump operation to get extra lock info
88 String pidArg = args[optionCount];
89 String params[]= new String[] { "" };
90 if (extended) {
91 params[0] += "-e ";
92 }
93 if (locks) {
94 params[0] += "-l";
95 }
96
97 ProcessArgumentMatcher ap = new ProcessArgumentMatcher(pidArg);
98 Collection<String> pids = ap.getVirtualMachinePids(JStack.class);
99
100 if (pids.isEmpty()) {
101 System.err.println("Could not find any processes matching : '" + pidArg + "'");
102 System.exit(1);
103 }
104
105 for (String pid : pids) {
106 if (pids.size() > 1) {
107 System.out.println("Pid:" + pid);
108 }
109 runThreadDump(pid, params);
110 }
111 }
112
113 // Attach to pid and perform a thread dump
114 private static void runThreadDump(String pid, String args[]) throws Exception {
115 VirtualMachine vm = null;
116 try {
117 vm = VirtualMachine.attach(pid);
118 } catch (Exception x) {
119 String msg = x.getMessage();
120 if (msg != null) {
121 System.err.println(pid + ": " + msg);
122 } else {
123 x.printStackTrace();
124 }
125 System.exit(1);
126 }
127
128 // Cast to HotSpotVirtualMachine as this is implementation specific
129 // method.
130 InputStream in = ((HotSpotVirtualMachine)vm).remoteDataDump((Object[])args);
131
132 // read to EOF and just print output
133 byte b[] = new byte[256];
134 int n;
135 do {
136 n = in.read(b);
137 if (n > 0) {
138 String s = new String(b, 0, n, "UTF-8");
139 System.out.print(s);
140 }
141 } while (n > 0);
142 in.close();
143 vm.detach();
144 }
145
146 private static void checkForUnsupportedOptions(String[] args) {
147 // Check arguments for -F, -m, and non-numeric value
148 // and warn the user that SA is not supported anymore
149
150 int paramCount = 0;
151
152 for (String s : args) {
153 if (s.equals("-F")) {
154 SAOptionError("-F option used");
155 }
156
157 if (s.equals("-m")) {
158 SAOptionError("-m option used");
159 }
160
161 if (! s.startsWith("-")) {
162 paramCount += 1;
163 }
164 }
165
166 if (paramCount > 1) {
167 SAOptionError("More than one non-option argument");
168 }
169 }
170
171 private static void SAOptionError(String msg) {
172 System.err.println("Error: " + msg);
173 System.err.println("Cannot connect to core dump or remote debug server. Use jhsdb jstack instead");
174 System.exit(1);
175 }
176
177 // print usage message
178 private static void usage(int exit) {
179 System.err.println("Usage:");
180 System.err.println(" jstack [-l][-e] <pid>");
181 System.err.println(" (to connect to running process)");
182 System.err.println("");
183 System.err.println("Options:");
184 System.err.println(" -l long listing. Prints additional information about locks");
185 System.err.println(" -e extended listing. Prints additional information about threads");
186 System.err.println(" -? -h --help -help to print this help message");
187 System.exit(exit);
188 }
189 }