jdk

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/*
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 * Copyright (c) 2012 SAP SE. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 */
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/*
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 * @test FieldMonitor.java
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 * @bug 7158988
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 * @requires vm.jvmti
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 * @summary verify jvm does not crash while debugging
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 * @run compile TestPostFieldModification.java
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 * @run main/othervm FieldMonitor
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 * @author axel.siebenborn@sap.com
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 */
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import java.io.BufferedReader;
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import java.io.IOException;
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import java.io.InputStream;
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import java.io.InputStreamReader;
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import java.util.Iterator;
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import java.util.List;
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import java.util.Map;
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import com.sun.jdi.Bootstrap;
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import com.sun.jdi.Field;
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import com.sun.jdi.ReferenceType;
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import com.sun.jdi.VirtualMachine;
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import com.sun.jdi.connect.Connector;
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import com.sun.jdi.connect.IllegalConnectorArgumentsException;
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import com.sun.jdi.connect.LaunchingConnector;
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import com.sun.jdi.connect.VMStartException;
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import com.sun.jdi.event.ClassPrepareEvent;
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import com.sun.jdi.event.Event;
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import com.sun.jdi.event.EventQueue;
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import com.sun.jdi.event.EventSet;
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import com.sun.jdi.event.ModificationWatchpointEvent;
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import com.sun.jdi.event.VMDeathEvent;
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import com.sun.jdi.event.VMStartEvent;
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import com.sun.jdi.event.VMDisconnectEvent;
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import com.sun.jdi.request.ClassPrepareRequest;
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import com.sun.jdi.request.EventRequest;
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import com.sun.jdi.request.EventRequestManager;
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import com.sun.jdi.request.ModificationWatchpointRequest;
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public class FieldMonitor {
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  public static final String CLASS_NAME = "TestPostFieldModification";
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  public static final String FIELD_NAME = "value";
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  public static final String ARGUMENTS = "-Xshare:off -Xlog:gc";
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  public static void main(String[] args)
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      throws IOException, InterruptedException {
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    //VirtualMachine vm = launchTarget(sb.toString());
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    VirtualMachine vm = launchTarget(CLASS_NAME);
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    System.out.println("Vm launched");
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    // process events
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    EventQueue eventQueue = vm.eventQueue();
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    // resume the vm
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    Process process = vm.process();
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    // Copy target's output and error to our output and error.
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    Thread outThread = new StreamRedirectThread("out reader", process.getInputStream());
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    Thread errThread = new StreamRedirectThread("error reader", process.getErrorStream());
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    errThread.start();
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    outThread.start();
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    boolean connected = true;
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    int watched = 0;
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    while (connected) {
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        try {
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            EventSet eventSet = eventQueue.remove();
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            for (Event event : eventSet) {
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              System.out.println("FieldMonitor-main receives: "+event);
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              if (event instanceof VMStartEvent) {
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                addClassWatch(vm);
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              } else if (event instanceof VMDeathEvent
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                  || event instanceof VMDisconnectEvent) {
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                // exit
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                connected = false;
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              } else if (event instanceof ClassPrepareEvent) {
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                // watch field on loaded class
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                System.out.println("ClassPrepareEvent");
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                ClassPrepareEvent classPrepEvent = (ClassPrepareEvent) event;
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                ReferenceType refType = classPrepEvent
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                    .referenceType();
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                addFieldWatch(vm, refType);
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              } else if (event instanceof ModificationWatchpointEvent) {
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                watched++;
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                System.out.println("sleep for 500 ms");
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                Thread.sleep(500);
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                ModificationWatchpointEvent modEvent = (ModificationWatchpointEvent) event;
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                System.out.println("old="
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                    + modEvent.valueCurrent());
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                System.out.println("new=" + modEvent.valueToBe());
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              }
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            }
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            System.out.println("resume...");
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            eventSet.resume();
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        } catch (com.sun.jdi.VMDisconnectedException exc) {
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            // Guess this means it's not connected anymore,
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            // sometimes this happens and everything else hangs, just return.
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            return;
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        }
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    }
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    // Shutdown begins when event thread terminates
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    try {
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        errThread.join(); // Make sure output is forwarded
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        outThread.join();
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    } catch (InterruptedException exc) {
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        // we don't interrupt
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    }
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    if (watched != 11) { // init + 10 modifications in TestPostFieldModification class
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        throw new Error("Expected to receive 11 times ModificationWatchpointEvent, but got "+watched);
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    }
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  }
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  /**
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   * Find a com.sun.jdi.CommandLineLaunch connector
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   */
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  static LaunchingConnector findLaunchingConnector() {
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    List <Connector> connectors = Bootstrap.virtualMachineManager().allConnectors();
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    Iterator <Connector> iter = connectors.iterator();
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    while (iter.hasNext()) {
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      Connector connector = iter.next();
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      if (connector.name().equals("com.sun.jdi.CommandLineLaunch")) {
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        return (LaunchingConnector)connector;
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      }
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    }
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    throw new Error("No launching connector");
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  }
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  /**
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   * Return the launching connector's arguments.
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   */
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 static Map <String,Connector.Argument> connectorArguments(LaunchingConnector connector, String mainArgs) {
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      Map<String,Connector.Argument> arguments = connector.defaultArguments();
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      for (String key : arguments.keySet()) {
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        System.out.println(key);
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      }
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      Connector.Argument mainArg = (Connector.Argument)arguments.get("main");
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      if (mainArg == null) {
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          throw new Error("Bad launching connector");
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      }
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      mainArg.setValue(mainArgs);
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      Connector.Argument optionsArg = (Connector.Argument)arguments.get("options");
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      if (optionsArg == null) {
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        throw new Error("Bad launching connector");
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      }
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      optionsArg.setValue(ARGUMENTS);
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      return arguments;
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  }
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 static VirtualMachine launchTarget(String mainArgs) {
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    LaunchingConnector connector = findLaunchingConnector();
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    Map  arguments = connectorArguments(connector, mainArgs);
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    try {
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        return (VirtualMachine) connector.launch(arguments);
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    } catch (IOException exc) {
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        throw new Error("Unable to launch target VM: " + exc);
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    } catch (IllegalConnectorArgumentsException exc) {
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        throw new Error("Internal error: " + exc);
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    } catch (VMStartException exc) {
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        throw new Error("Target VM failed to initialize: " +
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                        exc.getMessage());
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    }
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}
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  private static void addClassWatch(VirtualMachine vm) {
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    EventRequestManager erm = vm.eventRequestManager();
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    ClassPrepareRequest classPrepareRequest = erm
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        .createClassPrepareRequest();
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    classPrepareRequest.addClassFilter(CLASS_NAME);
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    classPrepareRequest.setEnabled(true);
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  }
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  private static void addFieldWatch(VirtualMachine vm,
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      ReferenceType refType) {
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    EventRequestManager erm = vm.eventRequestManager();
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    Field field = refType.fieldByName(FIELD_NAME);
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    ModificationWatchpointRequest modificationWatchpointRequest = erm
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        .createModificationWatchpointRequest(field);
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    modificationWatchpointRequest.setSuspendPolicy(EventRequest.SUSPEND_EVENT_THREAD);
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    modificationWatchpointRequest.setEnabled(true);
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  }
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}
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class StreamRedirectThread extends Thread {
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  private final BufferedReader in;
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  private static final int BUFFER_SIZE = 2048;
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  /**
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   * Set up for copy.
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   * @param name  Name of the thread
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   * @param in    Stream to copy from
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   * @param out   Stream to copy to
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   */
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  StreamRedirectThread(String name, InputStream in) {
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    super(name);
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    this.in = new BufferedReader(new InputStreamReader(in));
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  }
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  /**
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   * Copy.
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   */
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  public void run() {
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    try {
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      String line;
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        while ((line = in.readLine ()) != null) {
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          System.out.println ("testvm: " + line);
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      }
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     System.out.flush();
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    } catch(IOException exc) {
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      System.err.println("Child I/O Transfer - " + exc);
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    }
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  }
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}
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