/*
* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
package com.github.dcevm;
import com.sun.jdi.Bootstrap;
import com.sun.jdi.ReferenceType;
import com.sun.jdi.VirtualMachine;
import com.sun.jdi.VirtualMachineManager;
import com.sun.jdi.connect.AttachingConnector;
import com.sun.jdi.connect.Connector.Argument;
import com.sun.jdi.connect.IllegalConnectorArgumentsException;
import java.io.IOException;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Utility class for performing class redefinition using JDI.
* </li>
* </ul>
*
* @author Thomas Wuerthinger
* @author Kerstin Breiteneder
* @author Christoph Wimberger
*
*/
public class JDIRedefiner implements Redefiner {
private static final String PORT_ARGUMENT_NAME = "port";
private static final String TRANSPORT_NAME = "dt_socket";
private VirtualMachine vm;
/** Port at which to connect to the agent of the VM. **/
public static final int PORT = 4000;
public JDIRedefiner(int port) throws IOException {
vm = connect(port);
}
@Override
public void close() throws IOException {
disconnect();
}
private VirtualMachine connect(int port) throws IOException {
VirtualMachineManager manager = Bootstrap.virtualMachineManager();
// Find appropiate connector
List<AttachingConnector> connectors = manager.attachingConnectors();
AttachingConnector chosenConnector = null;
for (AttachingConnector c : connectors) {
if (c.transport().name().equals(TRANSPORT_NAME)) {
chosenConnector = c;
break;
}
}
if (chosenConnector == null) {
throw new IllegalStateException("Could not find socket connector");
}
// Set port argument
AttachingConnector connector = chosenConnector;
Map<String, Argument> defaults = connector.defaultArguments();
Argument arg = defaults.get(PORT_ARGUMENT_NAME);
if (arg == null) {
throw new IllegalStateException("Could not find port argument");
}
arg.setValue(Integer.toString(port));
// Attach
try {
System.out.println("Connector arguments: " + defaults);
return connector.attach(defaults);
} catch (IllegalConnectorArgumentsException e) {
throw new IllegalArgumentException("Illegal connector arguments", e);
}
}
public void disconnect() {
if (vm != null) {
vm.dispose();
vm = null;
}
}
public void redefineClasses(Map<Class<?>, byte[]> classes) {
refreshAllClasses();
List<ReferenceType> references = vm.allClasses();
Map<ReferenceType, byte[]> map = new HashMap<ReferenceType, byte[]>(classes.size());
for (Map.Entry<Class<?>, byte[]> entry : classes.entrySet()) {
map.put(findReference(references, entry.getKey().getName()), entry.getValue());
}
vm.redefineClasses(map);
}
/**
* Call this method before calling allClasses() in order to refresh the JDI state of loaded classes.
* This is necessary because the JDI map of all loaded classes is only updated based on events received over JDWP (network connection)
* and therefore it is not necessarily up-to-date with the real state within the VM.
*/
private void refreshAllClasses() {
try {
Field f = vm.getClass().getDeclaredField("retrievedAllTypes");
f.setAccessible(true);
f.set(vm, false);
} catch (IllegalArgumentException ex) {
Logger.getLogger(HotSwapTool.class.getName()).log(Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
Logger.getLogger(HotSwapTool.class.getName()).log(Level.SEVERE, null, ex);
} catch (NoSuchFieldException ex) {
Logger.getLogger(HotSwapTool.class.getName()).log(Level.SEVERE, null, ex);
} catch (SecurityException ex) {
Logger.getLogger(HotSwapTool.class.getName()).log(Level.SEVERE, null, ex);
}
}
private static ReferenceType findReference(List<ReferenceType> list, String name) {
for (ReferenceType ref : list) {
if (ref.name().equals(name)) {
return ref;
}
}
throw new IllegalArgumentException("Cannot find corresponding reference for class name '" + name + "'" );
}
}