FieldMonitor.java revision 9727:f944761a3ce3 
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 */
33import java.io.BufferedReader;
34import java.io.IOException;
35import java.io.InputStream;
36import java.io.InputStreamReader;
37import java.util.Iterator;
38import java.util.List;
39import java.util.Map;
40
41import com.sun.jdi.Bootstrap;
42import com.sun.jdi.Field;
43import com.sun.jdi.ReferenceType;
44import com.sun.jdi.VirtualMachine;
45import com.sun.jdi.connect.Connector;
46import com.sun.jdi.connect.IllegalConnectorArgumentsException;
47import com.sun.jdi.connect.LaunchingConnector;
48import com.sun.jdi.connect.VMStartException;
49import com.sun.jdi.event.ClassPrepareEvent;
50import com.sun.jdi.event.Event;
51import com.sun.jdi.event.EventQueue;
52import com.sun.jdi.event.EventSet;
53import com.sun.jdi.event.ModificationWatchpointEvent;
54import com.sun.jdi.event.VMDeathEvent;
55import com.sun.jdi.event.VMStartEvent;
56import com.sun.jdi.event.VMDisconnectEvent;
57import com.sun.jdi.request.ClassPrepareRequest;
58import com.sun.jdi.request.EventRequest;
59import com.sun.jdi.request.EventRequestManager;
60import com.sun.jdi.request.ModificationWatchpointRequest;
61
62public class FieldMonitor {
63
64  public static final String CLASS_NAME = "TestPostFieldModification";
65  public static final String FIELD_NAME = "value";
66  public static final String ARGUMENTS = "-Xshare:off -Xlog:gc";
67
68  public static void main(String[] args)
69      throws IOException, InterruptedException {
70
71    //VirtualMachine vm = launchTarget(sb.toString());
72    VirtualMachine vm = launchTarget(CLASS_NAME);
73
74    System.out.println("Vm launched");
75
76    // process events
77    EventQueue eventQueue = vm.eventQueue();
78    // resume the vm
79
80    Process process = vm.process();
81
82
83    // Copy target's output and error to our output and error.
84    Thread outThread = new StreamRedirectThread("out reader", process.getInputStream());
85    Thread errThread = new StreamRedirectThread("error reader", process.getErrorStream());
86
87    errThread.start();
88    outThread.start();
89
90    boolean connected = true;
91    int watched = 0;
92    while (connected) {
93        try {
94            EventSet eventSet = eventQueue.remove();
95            for (Event event : eventSet) {
96              System.out.println("FieldMonitor-main receives: "+event);
97              if (event instanceof VMStartEvent) {
98                addClassWatch(vm);
99              } else if (event instanceof VMDeathEvent
100                  || event instanceof VMDisconnectEvent) {
101                // exit
102                connected = false;
103              } else if (event instanceof ClassPrepareEvent) {
104                // watch field on loaded class
105                System.out.println("ClassPrepareEvent");
106                ClassPrepareEvent classPrepEvent = (ClassPrepareEvent) event;
107                ReferenceType refType = classPrepEvent
108                    .referenceType();
109                addFieldWatch(vm, refType);
110              } else if (event instanceof ModificationWatchpointEvent) {
111                watched++;
112                System.out.println("sleep for 500 ms");
113                Thread.sleep(500);
114
115                ModificationWatchpointEvent modEvent = (ModificationWatchpointEvent) event;
116                System.out.println("old="
117                    + modEvent.valueCurrent());
118                System.out.println("new=" + modEvent.valueToBe());
119              }
120            }
121            System.out.println("resume...");
122            eventSet.resume();
123        } catch (com.sun.jdi.VMDisconnectedException exc) {
124            // Guess this means it's not connected anymore,
125            // sometimes this happens and everything else hangs, just return.
126            return;
127        }
128    }
129    // Shutdown begins when event thread terminates
130    try {
131        errThread.join(); // Make sure output is forwarded
132        outThread.join();
133    } catch (InterruptedException exc) {
134        // we don't interrupt
135    }
136
137    if (watched != 11) { // init + 10 modifications in TestPostFieldModification class
138        throw new Error("Expected to receive 11 times ModificationWatchpointEvent, but got "+watched);
139    }
140  }
141
142  /**
143   * Find a com.sun.jdi.CommandLineLaunch connector
144   */
145  static LaunchingConnector findLaunchingConnector() {
146    List <Connector> connectors = Bootstrap.virtualMachineManager().allConnectors();
147    Iterator <Connector> iter = connectors.iterator();
148    while (iter.hasNext()) {
149      Connector connector = iter.next();
150      if (connector.name().equals("com.sun.jdi.CommandLineLaunch")) {
151        return (LaunchingConnector)connector;
152      }
153    }
154    throw new Error("No launching connector");
155  }
156  /**
157   * Return the launching connector's arguments.
158   */
159 static Map <String,Connector.Argument> connectorArguments(LaunchingConnector connector, String mainArgs) {
160      Map<String,Connector.Argument> arguments = connector.defaultArguments();
161      for (String key : arguments.keySet()) {
162        System.out.println(key);
163      }
164
165      Connector.Argument mainArg = (Connector.Argument)arguments.get("main");
166      if (mainArg == null) {
167          throw new Error("Bad launching connector");
168      }
169      mainArg.setValue(mainArgs);
170
171      Connector.Argument optionsArg = (Connector.Argument)arguments.get("options");
172      if (optionsArg == null) {
173        throw new Error("Bad launching connector");
174      }
175      optionsArg.setValue(ARGUMENTS);
176      return arguments;
177  }
178
179 static VirtualMachine launchTarget(String mainArgs) {
180    LaunchingConnector connector = findLaunchingConnector();
181    Map  arguments = connectorArguments(connector, mainArgs);
182    try {
183        return (VirtualMachine) connector.launch(arguments);
184    } catch (IOException exc) {
185        throw new Error("Unable to launch target VM: " + exc);
186    } catch (IllegalConnectorArgumentsException exc) {
187        throw new Error("Internal error: " + exc);
188    } catch (VMStartException exc) {
189        throw new Error("Target VM failed to initialize: " +
190                        exc.getMessage());
191    }
192}
193
194
195  private static void addClassWatch(VirtualMachine vm) {
196    EventRequestManager erm = vm.eventRequestManager();
197    ClassPrepareRequest classPrepareRequest = erm
198        .createClassPrepareRequest();
199    classPrepareRequest.addClassFilter(CLASS_NAME);
200    classPrepareRequest.setEnabled(true);
201  }
202
203
204  private static void addFieldWatch(VirtualMachine vm,
205      ReferenceType refType) {
206    EventRequestManager erm = vm.eventRequestManager();
207    Field field = refType.fieldByName(FIELD_NAME);
208    ModificationWatchpointRequest modificationWatchpointRequest = erm
209        .createModificationWatchpointRequest(field);
210    modificationWatchpointRequest.setSuspendPolicy(EventRequest.SUSPEND_EVENT_THREAD);
211    modificationWatchpointRequest.setEnabled(true);
212  }
213}
214
215class StreamRedirectThread extends Thread {
216
217  private final BufferedReader in;
218
219  private static final int BUFFER_SIZE = 2048;
220
221  /**
222   * Set up for copy.
223   * @param name  Name of the thread
224   * @param in    Stream to copy from
225   * @param out   Stream to copy to
226   */
227  StreamRedirectThread(String name, InputStream in) {
228    super(name);
229    this.in = new BufferedReader(new InputStreamReader(in));
230  }
231
232  /**
233   * Copy.
234   */
235  public void run() {
236    try {
237      String line;
238        while ((line = in.readLine ()) != null) {
239          System.out.println ("testvm: " + line);
240      }
241     System.out.flush();
242    } catch(IOException exc) {
243      System.err.println("Child I/O Transfer - " + exc);
244    }
245  }
246}
247