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