1 /* 2 * Copyright (c) 2005, 2020, 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.jmap; 27 28 import java.io.File; 29 import java.io.IOException; 30 import java.io.InputStream; 31 import java.io.UnsupportedEncodingException; 32 import java.util.Collection; 33 34 import com.sun.tools.attach.VirtualMachine; 35 import com.sun.tools.attach.VirtualMachineDescriptor; 36 import com.sun.tools.attach.AttachNotSupportedException; 37 import sun.tools.attach.HotSpotVirtualMachine; 38 import sun.tools.common.ProcessArgumentMatcher; 39 40 /* 41 * This class is the main class for the JMap utility. It parses its arguments 42 * and decides if the command should be satisfied using the VM attach mechanism 43 * or an SA tool. At this time the only option that uses the VM attach mechanism 44 * is the -dump option to get a heap dump of a running application. All other 45 * options are mapped to SA tools. 46 */ 47 public class JMap { 48 49 public static void main(String[] args) throws Exception { 50 if (args.length == 0) { 51 usage(1); // no arguments 52 } 53 54 checkForUnsupportedOptions(args); 55 56 // the chosen option 57 String option = null; 58 59 // First iterate over the options (arguments starting with -). There should be 60 // one. 61 int optionCount = 0; 62 while (optionCount < args.length) { 63 String arg = args[optionCount]; 64 if (!arg.startsWith("-")) { 65 break; 66 } 67 if (arg.equals("-?") || 68 arg.equals("-h") || 69 arg.equals("--help") || 70 // -help: legacy. Undocumented. 71 arg.equals("-help")) { 72 usage(0); 73 } else { 74 if (option != null) { 75 usage(1); // option already specified 76 } 77 option = arg; 78 } 79 optionCount++; 80 } 81 82 // if no option provided then use default. 83 if (option == null) { 84 usage(0); 85 } 86 87 // Next we check the parameter count. 88 int paramCount = args.length - optionCount; 89 if (paramCount != 1) { 90 usage(1); 91 } 92 93 String pidArg = args[1]; 94 // Here we handle the built-in options 95 // As more options are added we should create an abstract tool class and 96 // have a table to map the options 97 ProcessArgumentMatcher ap = new ProcessArgumentMatcher(pidArg); 98 Collection<String> pids = ap.getVirtualMachinePids(JMap.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 if (option.equals("-histo")) { 110 histo(pid, ""); 111 } else if (option.startsWith("-histo:")) { 112 histo(pid, option.substring("-histo:".length())); 113 } else if (option.startsWith("-dump:")) { 114 dump(pid, option.substring("-dump:".length())); 115 } else if (option.equals("-finalizerinfo")) { 116 executeCommandForPid(pid, "jcmd", "GC.finalizer_info"); 117 } else if (option.equals("-clstats")) { 118 executeCommandForPid(pid, "jcmd", "VM.classloader_stats"); 119 } else { 120 usage(1); 121 } 122 } 123 } 124 125 private static void executeCommandForPid(String pid, String command, Object ... args) 126 throws AttachNotSupportedException, IOException, 127 UnsupportedEncodingException { 128 VirtualMachine vm = VirtualMachine.attach(pid); 129 130 // Cast to HotSpotVirtualMachine as this is an 131 // implementation specific method. 132 HotSpotVirtualMachine hvm = (HotSpotVirtualMachine) vm; 133 try (InputStream in = hvm.executeCommand(command, args)) { 134 // read to EOF and just print output 135 byte b[] = new byte[256]; 136 int n; 137 do { 138 n = in.read(b); 139 if (n > 0) { 140 String s = new String(b, 0, n, "UTF-8"); 141 System.out.print(s); 142 } 143 } while (n > 0); 144 } 145 vm.detach(); 146 } 147 148 private static String parseFileName(String opt) { 149 // opt starts with "file=" 150 if (opt.length() > 5) { 151 // pass whole "file=" string 152 String filename = opt.substring(5); 153 try { 154 // Get the canonical path - important to avoid just 155 // passing a "heap.bin" and having the dump created 156 // in the target VM working directory rather than the 157 // directory where jmap is executed. 158 return new File(filename).getCanonicalPath(); 159 } catch (IOException ioe) { 160 return null; 161 } 162 } 163 // no filename 164 return null; 165 } 166 167 private static void histo(String pid, String options) 168 throws AttachNotSupportedException, IOException, 169 UnsupportedEncodingException { 170 String liveopt = "-all"; 171 String filename = null; 172 String parallel = null; 173 String subopts[] = options.split(","); 174 boolean set_all = false; 175 boolean set_live = false; 176 177 for (int i = 0; i < subopts.length; i++) { 178 String subopt = subopts[i]; 179 if (subopt.equals("") || subopt.equals("all")) { 180 set_all = true; 181 liveopt = "-all"; 182 } else if (subopt.equals("live")) { 183 // Add '-' for compatibility. 184 set_live = true; 185 liveopt = "-live"; 186 } else if (subopt.startsWith("file=")) { 187 filename = parseFileName(subopt); 188 if (filename == null) { 189 usage(1); // invalid options or no filename 190 } 191 } else if (subopt.startsWith("parallel=")) { 192 parallel = subopt.substring("parallel=".length()); 193 if (parallel == null) { 194 usage(1); 195 } 196 } else { 197 usage(1); 198 } 199 } 200 if (set_live && set_all) { 201 usage(1); 202 } 203 204 System.out.flush(); 205 // inspectHeap is not the same as jcmd GC.class_histogram 206 executeCommandForPid(pid, "inspectheap", liveopt, filename, parallel); 207 } 208 209 private static void dump(String pid, String options) 210 throws AttachNotSupportedException, IOException, 211 UnsupportedEncodingException { 212 213 String subopts[] = options.split(","); 214 String filename = null; 215 String liveopt = "-all"; 216 217 for (int i = 0; i < subopts.length; i++) { 218 String subopt = subopts[i]; 219 if (subopt.equals("live")) { 220 liveopt = "-live"; 221 } else if (subopt.startsWith("file=")) { 222 filename = parseFileName(subopt); 223 } 224 } 225 226 if (filename == null) { 227 usage(1); // invalid options or no filename 228 } 229 230 // dumpHeap is not the same as jcmd GC.heap_dump 231 executeCommandForPid(pid, "dumpheap", filename, liveopt); 232 } 233 234 private static void checkForUnsupportedOptions(String[] args) { 235 // Check arguments for -F, -m, and non-numeric value 236 // and warn the user that SA is not supported anymore 237 238 int paramCount = 0; 239 240 for (String s : args) { 241 if (s.equals("-F")) { 242 SAOptionError("-F option used"); 243 } 244 245 if (s.equals("-heap")) { 246 SAOptionError("-heap option used"); 247 } 248 249 /* Reimplemented using jcmd, output format is different 250 from original one 251 252 if (s.equals("-clstats")) { 253 warnSA("-clstats option used"); 254 } 255 256 if (s.equals("-finalizerinfo")) { 257 warnSA("-finalizerinfo option used"); 258 } 259 */ 260 261 if (! s.startsWith("-")) { 262 paramCount += 1; 263 } 264 } 265 266 if (paramCount > 1) { 267 SAOptionError("More than one non-option argument"); 268 } 269 } 270 271 private static void SAOptionError(String msg) { 272 System.err.println("Error: " + msg); 273 System.err.println("Cannot connect to core dump or remote debug server. Use jhsdb jmap instead"); 274 System.exit(1); 275 } 276 277 // print usage message 278 private static void usage(int exit) { 279 System.err.println("Usage:"); 280 System.err.println(" jmap -clstats <pid>"); 281 System.err.println(" to connect to running process and print class loader statistics"); 282 System.err.println(" jmap -finalizerinfo <pid>"); 283 System.err.println(" to connect to running process and print information on objects awaiting finalization"); 284 System.err.println(" jmap -histo[:[<histo-options>]] <pid>"); 285 System.err.println(" to connect to running process and print histogram of java object heap"); 286 System.err.println(" jmap -dump:<dump-options> <pid>"); 287 System.err.println(" to connect to running process and dump java heap"); 288 System.err.println(" jmap -? -h --help"); 289 System.err.println(" to print this help message"); 290 System.err.println(""); 291 System.err.println(" dump-options:"); 292 System.err.println(" live dump only live objects"); 293 System.err.println(" all dump all objects in the heap (default if one of \"live\" or \"all\" is not specified"); 294 System.err.println(" format=b binary format"); 295 System.err.println(" file=<file> dump heap to <file>"); 296 System.err.println(""); 297 System.err.println(" Example: jmap -dump:live,format=b,file=heap.bin <pid>"); 298 System.err.println(""); 299 System.err.println(" histo-options:"); 300 System.err.println(" live count only live objects"); 301 System.err.println(" all count all objects in the heap (default if one of \"live\" or \"all\" is not specified)"); 302 System.err.println(" file=<file> dump data to <file>"); 303 System.err.println(" parallel=<number> parallel threads number for heap iteration:"); 304 System.err.println(" parallel=0 default behavior, use predefined number of threads"); 305 System.err.println(" parallel=1 disable parallel heap iteration"); 306 System.err.println(" parallel=<N> use N threads for parallel heap iteration"); 307 System.err.println(""); 308 System.err.println(" Example: jmap -histo:live,file=/tmp/histo.data <pid>"); 309 System.exit(exit); 310 } 311 }