| /* |
| * Copyright (c) 2003, 2016, 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * 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 sun.instrument; |
| |
| import java.lang.instrument.Instrumentation; |
| import java.lang.instrument.ClassFileTransformer; |
| import java.security.ProtectionDomain; |
| |
| /* |
| * Copyright 2003 Wily Technology, Inc. |
| */ |
| |
| /** |
| * Support class for the InstrumentationImpl. Manages the list of registered transformers. |
| * Keeps everything in the right order, deals with sync of the list, |
| * and actually does the calling of the transformers. |
| */ |
| public class TransformerManager |
| { |
| private class TransformerInfo { |
| final ClassFileTransformer mTransformer; |
| String mPrefix; |
| |
| TransformerInfo(ClassFileTransformer transformer) { |
| mTransformer = transformer; |
| mPrefix = null; |
| } |
| |
| ClassFileTransformer transformer() { |
| return mTransformer; |
| } |
| |
| String getPrefix() { |
| return mPrefix; |
| } |
| |
| void setPrefix(String prefix) { |
| mPrefix = prefix; |
| } |
| } |
| |
| /** |
| * a given instance of this list is treated as immutable to simplify sync; |
| * we pay copying overhead whenever the list is changed rather than every time |
| * the list is referenced. |
| * The array is kept in the order the transformers are added via addTransformer |
| * (first added is 0, last added is length-1) |
| * Use an array, not a List or other Collection. This keeps the set of classes |
| * used by this code to a minimum. We want as few dependencies as possible in this |
| * code, since it is used inside the class definition system. Any class referenced here |
| * cannot be transformed by Java code. |
| */ |
| private TransformerInfo[] mTransformerList; |
| |
| /*** |
| * Is this TransformerManager for transformers capable of retransformation? |
| */ |
| private boolean mIsRetransformable; |
| |
| TransformerManager(boolean isRetransformable) { |
| mTransformerList = new TransformerInfo[0]; |
| mIsRetransformable = isRetransformable; |
| } |
| |
| boolean isRetransformable() { |
| return mIsRetransformable; |
| } |
| |
| public synchronized void |
| addTransformer( ClassFileTransformer transformer) { |
| TransformerInfo[] oldList = mTransformerList; |
| TransformerInfo[] newList = new TransformerInfo[oldList.length + 1]; |
| System.arraycopy( oldList, |
| 0, |
| newList, |
| 0, |
| oldList.length); |
| newList[oldList.length] = new TransformerInfo(transformer); |
| mTransformerList = newList; |
| } |
| |
| public synchronized boolean |
| removeTransformer(ClassFileTransformer transformer) { |
| boolean found = false; |
| TransformerInfo[] oldList = mTransformerList; |
| int oldLength = oldList.length; |
| int newLength = oldLength - 1; |
| |
| // look for it in the list, starting at the last added, and remember |
| // where it was if we found it |
| int matchingIndex = 0; |
| for ( int x = oldLength - 1; x >= 0; x-- ) { |
| if ( oldList[x].transformer() == transformer ) { |
| found = true; |
| matchingIndex = x; |
| break; |
| } |
| } |
| |
| // make a copy of the array without the matching element |
| if ( found ) { |
| TransformerInfo[] newList = new TransformerInfo[newLength]; |
| |
| // copy up to but not including the match |
| if ( matchingIndex > 0 ) { |
| System.arraycopy( oldList, |
| 0, |
| newList, |
| 0, |
| matchingIndex); |
| } |
| |
| // if there is anything after the match, copy it as well |
| if ( matchingIndex < (newLength) ) { |
| System.arraycopy( oldList, |
| matchingIndex + 1, |
| newList, |
| matchingIndex, |
| (newLength) - matchingIndex); |
| } |
| mTransformerList = newList; |
| } |
| return found; |
| } |
| |
| synchronized boolean |
| includesTransformer(ClassFileTransformer transformer) { |
| for (TransformerInfo info : mTransformerList) { |
| if ( info.transformer() == transformer ) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // This function doesn't actually snapshot anything, but should be |
| // used to set a local variable, which will snapshot the transformer |
| // list because of the copying semantics of mTransformerList (see |
| // the comment for mTransformerList). |
| private TransformerInfo[] |
| getSnapshotTransformerList() { |
| return mTransformerList; |
| } |
| |
| public byte[] |
| transform( Module module, |
| ClassLoader loader, |
| String classname, |
| Class<?> classBeingRedefined, |
| ProtectionDomain protectionDomain, |
| byte[] classfileBuffer) { |
| boolean someoneTouchedTheBytecode = false; |
| |
| TransformerInfo[] transformerList = getSnapshotTransformerList(); |
| |
| byte[] bufferToUse = classfileBuffer; |
| |
| // order matters, gotta run 'em in the order they were added |
| for ( int x = 0; x < transformerList.length; x++ ) { |
| TransformerInfo transformerInfo = transformerList[x]; |
| ClassFileTransformer transformer = transformerInfo.transformer(); |
| byte[] transformedBytes = null; |
| |
| try { |
| transformedBytes = transformer.transform( module, |
| loader, |
| classname, |
| classBeingRedefined, |
| protectionDomain, |
| bufferToUse); |
| } |
| catch (Throwable t) { |
| // don't let any one transformer mess it up for the others. |
| // This is where we need to put some logging. What should go here? FIXME |
| } |
| |
| if ( transformedBytes != null ) { |
| someoneTouchedTheBytecode = true; |
| bufferToUse = transformedBytes; |
| } |
| } |
| |
| // if someone modified it, return the modified buffer. |
| // otherwise return null to mean "no transforms occurred" |
| byte [] result; |
| if ( someoneTouchedTheBytecode ) { |
| result = bufferToUse; |
| } |
| else { |
| result = null; |
| } |
| |
| return result; |
| } |
| |
| |
| int |
| getTransformerCount() { |
| TransformerInfo[] transformerList = getSnapshotTransformerList(); |
| return transformerList.length; |
| } |
| |
| boolean |
| setNativeMethodPrefix(ClassFileTransformer transformer, String prefix) { |
| TransformerInfo[] transformerList = getSnapshotTransformerList(); |
| |
| for ( int x = 0; x < transformerList.length; x++ ) { |
| TransformerInfo transformerInfo = transformerList[x]; |
| ClassFileTransformer aTransformer = transformerInfo.transformer(); |
| |
| if ( aTransformer == transformer ) { |
| transformerInfo.setPrefix(prefix); |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| |
| String[] |
| getNativeMethodPrefixes() { |
| TransformerInfo[] transformerList = getSnapshotTransformerList(); |
| String[] prefixes = new String[transformerList.length]; |
| |
| for ( int x = 0; x < transformerList.length; x++ ) { |
| TransformerInfo transformerInfo = transformerList[x]; |
| prefixes[x] = transformerInfo.getPrefix(); |
| } |
| return prefixes; |
| } |
| } |