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 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 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 }