/**

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

  *

  * Copyright 2013-2014 Oracle and/or its affiliates. All rights reserved.

  *

  * Oracle and Java are registered trademarks of Oracle and/or its affiliates.

  * Other names may be trademarks of their respective owners.

  *

  * The contents of this file are subject to the terms of either the GNU

  * General Public License Version 2 only ("GPL") or the Common

  * Development and Distribution License("CDDL") (collectively, the

  * "License"). You may not use this file except in compliance with the

  * License. You can obtain a copy of the License at

  * http://www.netbeans.org/cddl-gplv2.html

  * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the

  * specific language governing permissions and limitations under the

  * License.  When distributing the software, include this License Header

  * Notice in each file and include the License file at

  * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the GPL Version 2 section of the License file that

  * accompanied this code. If applicable, add the following below the

  * License Header, with the fields enclosed by brackets [] replaced by

  * your own identifying information:

  * "Portions Copyrighted [year] [name of copyright owner]"

  *

  * Contributor(s):

  *

  * The Original Software is NetBeans. The Initial Developer of the Original

  * Software is Oracle. Portions Copyright 2013-2014 Oracle. All Rights Reserved.

  *

  * If you wish your version of this file to be governed by only the CDDL

  * or only the GPL Version 2, indicate your decision by adding

  * "[Contributor] elects to include this software in this distribution

  * under the [CDDL or GPL Version 2] license." If you do not indicate a

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  * your version of this file under either the CDDL, the GPL Version 2 or

  * to extend the choice of license to its licensees as provided above.

  * However, if you add GPL Version 2 code and therefore, elected the GPL

  * Version 2 license, then the option applies only if the new code is

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 package org.netbeans.html.equinox.agentclass;

 import java.lang.instrument.ClassDefinition;

 import java.lang.instrument.ClassFileTransformer;

 import java.lang.instrument.IllegalClassFormatException;

 import java.lang.instrument.Instrumentation;

 import java.lang.instrument.UnmodifiableClassException;

 import java.lang.reflect.InvocationTargetException;

 import java.lang.reflect.Method;

 import java.security.ProtectionDomain;

 import java.util.Collection;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Set;

 import java.util.concurrent.CopyOnWriteArrayList;

 import java.util.jar.JarFile;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 /**

  *

  * @author Jaroslav Tulach <jtulach@netbeans.org>

  */

 final class NbInstrumentation implements Instrumentation {

     private static final Logger LOG = Logger.getLogger(NbInstrumentation.class.getName());

     private static final Object LOCK = new Object();

     private static volatile Collection<NbInstrumentation> ACTIVE;

     private final List<ClassFileTransformer> transformers = new CopyOnWriteArrayList<ClassFileTransformer>();

     private static final ThreadLocal<Boolean> IN = new ThreadLocal<Boolean>();

     static NbInstrumentation registerAgent(ClassLoader l, String agentClassName) {

         try {

             return registerImpl(agentClassName, l);

         } catch (Throwable ex) {

             LOG.log(Level.WARNING, "Cannot register " + agentClassName, ex);

             return null;

         }

     }

     static void unregisterAgent(NbInstrumentation instr) {

         synchronized (LOCK) {

             if (ACTIVE != null) {

                 Collection<NbInstrumentation> clone = new HashSet<NbInstrumentation>();

                 clone.addAll(ACTIVE);

                 clone.remove(instr);

                 ACTIVE = clone;

             }

         }

     }

     private static NbInstrumentation registerImpl(String agentClassName, ClassLoader l) throws ClassNotFoundException, IllegalArgumentException, NoSuchMethodException, SecurityException, IllegalAccessException, InvocationTargetException {

         final NbInstrumentation inst = new NbInstrumentation();

         synchronized (LOCK) {

             if (ACTIVE == null) {

                 ACTIVE = new HashSet<NbInstrumentation>();

             } else {

                 Set<NbInstrumentation> s = new HashSet<NbInstrumentation>();

                 s.addAll(ACTIVE);

                 ACTIVE = s;

             }

             ACTIVE.add(inst);

         }

         Class<?> agentClass = Class.forName(agentClassName, true, l);

         try {

             Method m = agentClass.getMethod("agentmain", String.class, Instrumentation.class); // NOI18N

             m.invoke(null, "", inst);

         } catch (NoSuchMethodException ex) {

             Method m = agentClass.getMethod("agentmain", String.class); // NOI18N

             m.invoke(null, "");

         }

         return inst;

     }

     public static byte[] patchByteCode(ClassLoader l, String className, ProtectionDomain pd, byte[] arr) throws IllegalClassFormatException {

         if (ACTIVE == null) {

             return arr;

         }

         if (Boolean.TRUE.equals(IN.get())) {

             return arr;

         }

         try {

             IN.set(Boolean.TRUE);

             for (NbInstrumentation inst : ACTIVE) {

                 for (ClassFileTransformer t : inst.transformers) {

                     arr = t.transform(l, className, null, pd, arr);

                 }

             }

         } finally {

             IN.set(null);

         }

         return arr;

     }

     //

     // Instrumentation methods

     //

     @Override

     public void addTransformer(ClassFileTransformer transformer, boolean canRetransform) {

         transformers.add(transformer);

     }

     @Override

     public void addTransformer(ClassFileTransformer transformer) {

         transformers.add(transformer);

     }

     @Override

     public boolean removeTransformer(ClassFileTransformer transformer) {

         return transformers.remove(transformer);

     }

     @Override

     public boolean isRetransformClassesSupported() {

         return false;

     }

     @Override

     public void retransformClasses(Class<?>... classes) throws UnmodifiableClassException {

         throw new UnmodifiableClassException();

     }

     @Override

     public boolean isRedefineClassesSupported() {

         return false;

     }

     @Override

     public void redefineClasses(ClassDefinition... definitions) throws ClassNotFoundException, UnmodifiableClassException {

         throw new UnmodifiableClassException();

     }

     @Override

     public boolean isModifiableClass(Class<?> theClass) {

         return false;

     }

     @Override

     public Class[] getAllLoadedClasses() {

         return new Class[0];

     }

     @Override

     public Class[] getInitiatedClasses(ClassLoader loader) {

         return new Class[0];

     }

     @Override

     public long getObjectSize(Object objectToSize) {

         return 42;

     }

     @Override

     public void appendToBootstrapClassLoaderSearch(JarFile jarfile) {

     }

     @Override

     public void appendToSystemClassLoaderSearch(JarFile jarfile) {

         throw new UnsupportedOperationException();

     }

     @Override

     public boolean isNativeMethodPrefixSupported() {

         return false;

     }

     @Override

     public void setNativeMethodPrefix(ClassFileTransformer transformer, String prefix) {

         throw new UnsupportedOperationException();

     }

 }