1 /*
2 * Copyright (c) 2006, 2011, 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.jinfo;
27
28 import java.lang.reflect.Method;
29 import java.io.File;
30 import java.io.IOException;
31 import java.io.InputStream;
32
33 import com.sun.tools.attach.VirtualMachine;
34 import sun.tools.attach.HotSpotVirtualMachine;
35
36 /*
37 * This class is the main class for the JInfo utility. It parses its arguments
38 * and decides if the command should be satisfied using the VM attach mechanism
39 * or an SA tool. At this time the only option that uses the VM attach
40 * mechanism is the -flag option to set or print a command line option of a
41 * running application. All other options are mapped to SA tools.
42 */
43 public class JInfo {
44
45 public static void main(String[] args) throws Exception {
46 if (args.length == 0) {
47 usage(1); // no arguments
48 }
49
50 boolean useSA = true;
51 String arg1 = args[0];
52 if (arg1.startsWith("-")) {
53 if (arg1.equals("-flags") ||
54 arg1.equals("-sysprops")) {
55 // SA JInfo needs <pid> or <server> or
56 // (<executable> and <code file>). So, total
57 // argument count including option has to 2 or 3.
58 if (args.length != 2 && args.length != 3) {
59 usage(1);
60 }
61 } else if (arg1.equals("-flag")) {
62 // do not use SA, use attach-on-demand
63 useSA = false;
64 } else {
65 // unknown option or -h or -help, print help
66 int exit;
67 if (arg1.equals("-help") || arg1.equals("-h")) {
68 exit = 0;
69 } else {
70 exit = 1;
71 }
72 usage(exit);
73 }
74 }
75
76 if (useSA) {
77 runTool(args);
78 } else {
79 if (args.length == 3) {
80 String pid = args[2];
81 String option = args[1];
82 flag(pid, option);
83 } else {
84 int exit = arg1.equals("-help") || arg1.equals("-h") ? 0 : 1;
85 usage(exit);
86 }
87 }
88 }
89
90 // Invoke SA tool with the given arguments
91 private static void runTool(String args[]) throws Exception {
92 String tool = "sun.jvm.hotspot.tools.JInfo";
93 // Tool not available on this platform.
94 Class<?> c = loadClass(tool);
95 if (c == null) {
96 usage(1);
97 }
98
99 // invoke the main method with the arguments
100 Class[] argTypes = { String[].class } ;
101 Method m = c.getDeclaredMethod("main", argTypes);
102
103 Object[] invokeArgs = { args };
104 m.invoke(null, invokeArgs);
105 }
106
107 // loads the given class using the system class loader
108 private static Class<?> loadClass(String name) {
109 //
110 // We specify the system clas loader so as to cater for development
111 // environments where this class is on the boot class path but sa-jdi.jar
112 // is on the system class path. Once the JDK is deployed then both
113 // tools.jar and sa-jdi.jar are on the system class path.
114 //
115 try {
116 return Class.forName(name, true,
117 ClassLoader.getSystemClassLoader());
118 } catch (Exception x) { }
119 return null;
120 }
121
122 private static void flag(String pid, String option) throws IOException {
123 VirtualMachine vm = attach(pid);
124 String flag;
125 InputStream in;
126 int index = option.indexOf('=');
127 if (index != -1) {
128 flag = option.substring(0, index);
129 String value = option.substring(index + 1);
130 in = ((HotSpotVirtualMachine)vm).setFlag(flag, value);
131 } else {
132 char c = option.charAt(0);
133 switch (c) {
134 case '+':
135 flag = option.substring(1);
136 in = ((HotSpotVirtualMachine)vm).setFlag(flag, "1");
137 break;
138 case '-':
139 flag = option.substring(1);
140 in = ((HotSpotVirtualMachine)vm).setFlag(flag, "0");
141 break;
142 default:
143 flag = option;
144 in = ((HotSpotVirtualMachine)vm).printFlag(flag);
145 break;
146 }
147 }
148
149 drain(vm, in);
150 }
151
152 // Attach to <pid>, exiting if we fail to attach
153 private static VirtualMachine attach(String pid) {
154 try {
155 return VirtualMachine.attach(pid);
156 } catch (Exception x) {
157 String msg = x.getMessage();
158 if (msg != null) {
159 System.err.println(pid + ": " + msg);
160 } else {
161 x.printStackTrace();
162 }
163 System.exit(1);
164 return null; // keep compiler happy
165 }
166 }
167
168 // Read the stream from the target VM until EOF, then detach
169 private static void drain(VirtualMachine vm, InputStream in) throws IOException {
170 // read to EOF and just print output
171 byte b[] = new byte[256];
172 int n;
173 do {
174 n = in.read(b);
175 if (n > 0) {
176 String s = new String(b, 0, n, "UTF-8");
177 System.out.print(s);
178 }
179 } while (n > 0);
180 in.close();
181 vm.detach();
182 }
183
184
185 // print usage message
186 private static void usage(int exit) {
187
188 Class<?> c = loadClass("sun.jvm.hotspot.tools.JInfo");
189 boolean usageSA = (c != null);
190
191 System.err.println("Usage:");
192 if (usageSA) {
193 System.err.println(" jinfo [option] <pid>");
194 System.err.println(" (to connect to running process)");
195 System.err.println(" jinfo [option] <executable <core>");
196 System.err.println(" (to connect to a core file)");
197 System.err.println(" jinfo [option] [server_id@]<remote server IP or hostname>");
198 System.err.println(" (to connect to remote debug server)");
199 System.err.println("");
200 System.err.println("where <option> is one of:");
201 System.err.println(" -flag <name> to print the value of the named VM flag");
202 System.err.println(" -flag [+|-]<name> to enable or disable the named VM flag");
203 System.err.println(" -flag <name>=<value> to set the named VM flag to the given value");
204 System.err.println(" -flags to print VM flags");
205 System.err.println(" -sysprops to print Java system properties");
206 System.err.println(" <no option> to print both of the above");
207 System.err.println(" -h | -help to print this help message");
208 } else {
209 System.err.println(" jinfo <option> <pid>");
210 System.err.println(" (to connect to a running process)");
211 System.err.println("");
212 System.err.println("where <option> is one of:");
213 System.err.println(" -flag <name> to print the value of the named VM flag");
214 System.err.println(" -flag [+|-]<name> to enable or disable the named VM flag");
215 System.err.println(" -flag <name>=<value> to set the named VM flag to the given value");
216 System.err.println(" -h | -help to print this help message");
217 }
218
219 System.exit(exit);
220 }
221 }