1 /* 2 * Copyright 2012 SAP AG. 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* 25 * @test FieldMonitor.java 26 * @bug 7158988 27 * @key regression 28 * @summary verify jvm does not crash while debugging 29 * @run compile TestPostFieldModification.java 30 * @run main/othervm FieldMonitor 31 * @author axel.siebenborn@sap.com 32 */ 33 import java.io.BufferedReader; 34 import java.io.IOException; 35 import java.io.InputStream; 36 import java.io.InputStreamReader; 37 import java.util.Iterator; 38 import java.util.List; 39 import java.util.Map; 40 import java.io.PrintWriter; 41 42 import com.sun.jdi.Bootstrap; 43 import com.sun.jdi.Field; 44 import com.sun.jdi.ReferenceType; 45 import com.sun.jdi.VirtualMachine; 46 import com.sun.jdi.connect.Connector; 47 import com.sun.jdi.connect.IllegalConnectorArgumentsException; 48 import com.sun.jdi.connect.LaunchingConnector; 49 import com.sun.jdi.connect.VMStartException; 50 import com.sun.jdi.event.ClassPrepareEvent; 51 import com.sun.jdi.event.VMStartEvent; 52 import com.sun.jdi.event.Event; 53 import com.sun.jdi.event.EventQueue; 54 import com.sun.jdi.event.EventSet; 55 import com.sun.jdi.event.ModificationWatchpointEvent; 56 import com.sun.jdi.event.VMDeathEvent; 57 import com.sun.jdi.event.VMDisconnectEvent; 58 import com.sun.jdi.request.ClassPrepareRequest; 59 import com.sun.jdi.request.EventRequest; 60 import com.sun.jdi.request.EventRequestManager; 61 import com.sun.jdi.request.ModificationWatchpointRequest; 62 63 public class FieldMonitor { 64 65 public static final String CLASS_NAME = "TestPostFieldModification"; 66 public static final String FIELD_NAME = "value"; 67 public static final String ARGUMENTS = "-Xshare:off -XX:+PrintGC"; 68 69 public static void main(String[] args) 70 throws IOException, InterruptedException { 71 72 VirtualMachine vm = launchTarget(CLASS_NAME); 73 EventQueue eventQueue = vm.eventQueue(); 74 75 // make sure the vm is started 76 boolean started = false; 77 while(!started) { 78 EventSet eventSet = eventQueue.remove(); 79 for (Event event : eventSet) { 80 if (event instanceof VMStartEvent) { 81 started = true; 82 } 83 if (event instanceof VMDeathEvent 84 || event instanceof VMDisconnectEvent) { 85 throw new Error("VM died before it started...:"+event); 86 } 87 } 88 } 89 90 System.out.println("Vm launched"); 91 92 // watch for loaded classes 93 addClassWatch(vm); 94 95 // process events 96 Process process = vm.process(); 97 98 99 // Copy target's output and error to our output and error. 100 Thread outThread = new StreamRedirectThread("out reader", process.getInputStream()); 101 Thread errThread = new StreamRedirectThread("error reader", process.getErrorStream()); 102 103 PrintWriter vmPrinter = null; 104 errThread.start(); 105 outThread.start(); 106 107 108 vm.resume(); 109 boolean connected = true; 110 while (connected) { 111 EventSet eventSet = eventQueue.remove(); 112 for (Event event : eventSet) { 113 if (event instanceof VMDeathEvent 114 || event instanceof VMDisconnectEvent) { 115 // exit 116 connected = false; 117 } else if (event instanceof ClassPrepareEvent) { 118 // watch field on loaded class 119 System.out.println("ClassPrepareEvent"); 120 ClassPrepareEvent classPrepEvent = (ClassPrepareEvent) event; 121 ReferenceType refType = classPrepEvent 122 .referenceType(); 123 addFieldWatch(vm, refType); 124 125 // inform TestPostFieldModification that it can exit. // JDK-8007710 126 if (vmPrinter == null) { 127 vmPrinter = new PrintWriter(process.getOutputStream()); 128 vmPrinter.println(""); 129 vmPrinter.flush(); 130 } 131 } else if (event instanceof ModificationWatchpointEvent) { 132 System.out.println("sleep for 500 ms"); 133 Thread.sleep(500); 134 System.out.println("resume..."); 135 136 ModificationWatchpointEvent modEvent = (ModificationWatchpointEvent) event; 137 System.out.println("old=" 138 + modEvent.valueCurrent()); 139 System.out.println("new=" + modEvent.valueToBe()); 140 System.out.println(); 141 } 142 } 143 eventSet.resume(); 144 } 145 // Shutdown begins when event thread terminates 146 try { 147 errThread.join(); // Make sure output is forwarded 148 outThread.join(); 149 } catch (InterruptedException exc) { 150 // we don't interrupt 151 } 152 } 153 154 /** 155 * Find a com.sun.jdi.CommandLineLaunch connector 156 */ 157 static LaunchingConnector findLaunchingConnector() { 158 List <Connector> connectors = Bootstrap.virtualMachineManager().allConnectors(); 159 Iterator <Connector> iter = connectors.iterator(); 160 while (iter.hasNext()) { 161 Connector connector = iter.next(); 162 if (connector.name().equals("com.sun.jdi.CommandLineLaunch")) { 163 return (LaunchingConnector)connector; 164 } 165 } 166 throw new Error("No launching connector"); 167 } 168 /** 169 * Return the launching connector's arguments. 170 */ 171 static Map <String,Connector.Argument> connectorArguments(LaunchingConnector connector, String mainArgs) { 172 Map<String,Connector.Argument> arguments = connector.defaultArguments(); 173 for (String key : arguments.keySet()) { 174 System.out.println(key); 175 } 176 177 Connector.Argument mainArg = (Connector.Argument)arguments.get("main"); 178 if (mainArg == null) { 179 throw new Error("Bad launching connector"); 180 } 181 mainArg.setValue(mainArgs); 182 183 Connector.Argument optionsArg = (Connector.Argument)arguments.get("options"); 184 if (optionsArg == null) { 185 throw new Error("Bad launching connector"); 186 } 187 optionsArg.setValue(ARGUMENTS); 188 return arguments; 189 } 190 191 static VirtualMachine launchTarget(String mainArgs) { 192 LaunchingConnector connector = findLaunchingConnector(); 193 Map arguments = connectorArguments(connector, mainArgs); 194 try { 195 return (VirtualMachine) connector.launch(arguments); 196 } catch (IOException exc) { 197 throw new Error("Unable to launch target VM: " + exc); 198 } catch (IllegalConnectorArgumentsException exc) { 199 throw new Error("Internal error: " + exc); 200 } catch (VMStartException exc) { 201 throw new Error("Target VM failed to initialize: " + 202 exc.getMessage()); 203 } 204 } 205 206 207 private static void addClassWatch(VirtualMachine vm) { 208 EventRequestManager erm = vm.eventRequestManager(); 209 ClassPrepareRequest classPrepareRequest = erm 210 .createClassPrepareRequest(); 211 classPrepareRequest.addClassFilter(CLASS_NAME); 212 classPrepareRequest.setEnabled(true); 213 } 214 215 216 private static void addFieldWatch(VirtualMachine vm, 217 ReferenceType refType) { 218 EventRequestManager erm = vm.eventRequestManager(); 219 Field field = refType.fieldByName(FIELD_NAME); 220 ModificationWatchpointRequest modificationWatchpointRequest = erm 221 .createModificationWatchpointRequest(field); 222 modificationWatchpointRequest.setSuspendPolicy(EventRequest.SUSPEND_EVENT_THREAD); 223 modificationWatchpointRequest.setEnabled(true); 224 } 225 } 226 227 class StreamRedirectThread extends Thread { 228 229 private final BufferedReader in; 230 231 private static final int BUFFER_SIZE = 2048; 232 233 /** 234 * Set up for copy. 235 * @param name Name of the thread 236 * @param in Stream to copy from 237 * @param out Stream to copy to 238 */ 239 StreamRedirectThread(String name, InputStream in) { 240 super(name); 241 this.in = new BufferedReader(new InputStreamReader(in)); 242 } 243 244 /** 245 * Copy. 246 */ 247 public void run() { 248 try { 249 String line; 250 while ((line = in.readLine ()) != null) { 251 System.out.println ("testvm: " + line); 252 } 253 System.out.flush(); 254 } catch(IOException exc) { 255 System.err.println("Child I/O Transfer - " + exc); 256 } 257 } 258 }