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| 1 | /* | ||
| 2 | * Copyright (c) 2003, 2005, Oracle and/or its affiliates. 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. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 10 | * | ||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 15 | * accompanied this code). | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License version | ||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | package sun.instrument; | ||
| 27 | |||
| 28 | |||
| 29 | import java.lang.instrument.Instrumentation; | ||
| 30 | import java.lang.instrument.ClassFileTransformer; | ||
| 31 | import java.security.ProtectionDomain; | ||
| 32 | |||
| 33 | /* | ||
| 34 | * Copyright 2003 Wily Technology, Inc. | ||
| 35 | */ | ||
| 36 | |||
| 37 | /** | ||
| 38 | * Support class for the InstrumentationImpl. Manages the list of registered transformers. | ||
| 39 | * Keeps everything in the right order, deals with sync of the list, | ||
| 40 | * and actually does the calling of the transformers. | ||
| 41 | */ | ||
| 42 | public class TransformerManager | ||
| 43 | { | ||
| 44 | private class TransformerInfo { | ||
| 45 | final ClassFileTransformer mTransformer; | ||
| 46 | String mPrefix; | ||
| 47 | |||
| 48 | TransformerInfo(ClassFileTransformer transformer) { | ||
| 49 | mTransformer = transformer; | ||
| 50 | mPrefix = null; | ||
| 51 | } | ||
| 52 | |||
| 53 | ClassFileTransformer transformer() { | ||
| 54 | return mTransformer; | ||
| 55 | } | ||
| 56 | |||
| 57 | String getPrefix() { | ||
| 58 | return mPrefix; | ||
| 59 | } | ||
| 60 | |||
| 61 | void setPrefix(String prefix) { | ||
| 62 | mPrefix = prefix; | ||
| 63 | } | ||
| 64 | } | ||
| 65 | |||
| 66 | /** | ||
| 67 | * a given instance of this list is treated as immutable to simplify sync; | ||
| 68 | * we pay copying overhead whenever the list is changed rather than every time | ||
| 69 | * the list is referenced. | ||
| 70 | * The array is kept in the order the transformers are added via addTransformer | ||
| 71 | * (first added is 0, last added is length-1) | ||
| 72 | * Use an array, not a List or other Collection. This keeps the set of classes | ||
| 73 | * used by this code to a minimum. We want as few dependencies as possible in this | ||
| 74 | * code, since it is used inside the class definition system. Any class referenced here | ||
| 75 | * cannot be transformed by Java code. | ||
| 76 | */ | ||
| 77 | private TransformerInfo[] mTransformerList; | ||
| 78 | |||
| 79 | /*** | ||
| 80 | * Is this TransformerManager for transformers capable of retransformation? | ||
| 81 | */ | ||
| 82 | private boolean mIsRetransformable; | ||
| 83 | |||
| 84 | TransformerManager(boolean isRetransformable) { | ||
| 85 | mTransformerList = new TransformerInfo[0]; | ||
| 86 | mIsRetransformable = isRetransformable; | ||
| 87 | } | ||
| 88 | |||
| 89 | boolean isRetransformable() { | ||
| 90 | return mIsRetransformable; | ||
| 91 | } | ||
| 92 | |||
| 93 | public synchronized void | ||
| 94 | addTransformer( ClassFileTransformer transformer) { | ||
| 95 | TransformerInfo[] oldList = mTransformerList; | ||
| 96 | TransformerInfo[] newList = new TransformerInfo[oldList.length + 1]; | ||
| 97 | System.arraycopy( oldList, | ||
| 98 | 0, | ||
| 99 | newList, | ||
| 100 | 0, | ||
| 101 | oldList.length); | ||
| 102 | newList[oldList.length] = new TransformerInfo(transformer); | ||
| 103 | mTransformerList = newList; | ||
| 104 | } | ||
| 105 | |||
| 106 | public synchronized boolean | ||
| 107 | removeTransformer(ClassFileTransformer transformer) { | ||
| 108 | boolean found = false; | ||
| 109 | TransformerInfo[] oldList = mTransformerList; | ||
| 110 | int oldLength = oldList.length; | ||
| 111 | int newLength = oldLength - 1; | ||
| 112 | |||
| 113 | // look for it in the list, starting at the last added, and remember | ||
| 114 | // where it was if we found it | ||
| 115 | int matchingIndex = 0; | ||
| 116 | for ( int x = oldLength - 1; x >= 0; x-- ) { | ||
| 117 | if ( oldList[x].transformer() == transformer ) { | ||
| 118 | found = true; | ||
| 119 | matchingIndex = x; | ||
| 120 | break; | ||
| 121 | } | ||
| 122 | } | ||
| 123 | |||
| 124 | // make a copy of the array without the matching element | ||
| 125 | if ( found ) { | ||
| 126 | TransformerInfo[] newList = new TransformerInfo[newLength]; | ||
| 127 | |||
| 128 | // copy up to but not including the match | ||
| 129 | if ( matchingIndex > 0 ) { | ||
| 130 | System.arraycopy( oldList, | ||
| 131 | 0, | ||
| 132 | newList, | ||
| 133 | 0, | ||
| 134 | matchingIndex); | ||
| 135 | } | ||
| 136 | |||
| 137 | // if there is anything after the match, copy it as well | ||
| 138 | if ( matchingIndex < (newLength) ) { | ||
| 139 | System.arraycopy( oldList, | ||
| 140 | matchingIndex + 1, | ||
| 141 | newList, | ||
| 142 | matchingIndex, | ||
| 143 | (newLength) - matchingIndex); | ||
| 144 | } | ||
| 145 | mTransformerList = newList; | ||
| 146 | } | ||
| 147 | return found; | ||
| 148 | } | ||
| 149 | |||
| 150 | synchronized boolean | ||
| 151 | includesTransformer(ClassFileTransformer transformer) { | ||
| 152 | for (TransformerInfo info : mTransformerList) { | ||
| 153 | if ( info.transformer() == transformer ) { | ||
| 154 | return true; | ||
| 155 | } | ||
| 156 | } | ||
| 157 | return false; | ||
| 158 | } | ||
| 159 | |||
| 160 | // This function doesn't actually snapshot anything, but should be | ||
| 161 | // used to set a local variable, which will snapshot the transformer | ||
| 162 | // list because of the copying semantics of mTransformerList (see | ||
| 163 | // the comment for mTransformerList). | ||
| 164 | private TransformerInfo[] | ||
| 165 | getSnapshotTransformerList() { | ||
| 166 | return mTransformerList; | ||
| 167 | } | ||
| 168 | |||
| 169 | public byte[] | ||
| 170 | transform( ClassLoader loader, | ||
| 171 | String classname, | ||
| 172 | Class classBeingRedefined, | ||
| 173 | ProtectionDomain protectionDomain, | ||
| 174 | byte[] classfileBuffer) { | ||
| 175 | boolean someoneTouchedTheBytecode = false; | ||
| 176 | |||
| 177 | TransformerInfo[] transformerList = getSnapshotTransformerList(); | ||
| 178 | |||
| 179 | byte[] bufferToUse = classfileBuffer; | ||
| 180 | |||
| 181 | // order matters, gotta run 'em in the order they were added | ||
| 182 | for ( int x = 0; x < transformerList.length; x++ ) { | ||
| 183 | TransformerInfo transformerInfo = transformerList[x]; | ||
| 184 | ClassFileTransformer transformer = transformerInfo.transformer(); | ||
| 185 | byte[] transformedBytes = null; | ||
| 186 | |||
| 187 | try { | ||
| 188 | transformedBytes = transformer.transform( loader, | ||
| 189 | classname, | ||
| 190 | classBeingRedefined, | ||
| 191 | protectionDomain, | ||
| 192 | bufferToUse); | ||
| 193 | } | ||
| 194 | catch (Throwable t) { | ||
| 195 | // don't let any one transformer mess it up for the others. | ||
| 196 | // This is where we need to put some logging. What should go here? FIXME | ||
| 197 | } | ||
| 198 | |||
| 199 | if ( transformedBytes != null ) { | ||
| 200 | someoneTouchedTheBytecode = true; | ||
| 201 | bufferToUse = transformedBytes; | ||
| 202 | } | ||
| 203 | } | ||
| 204 | |||
| 205 | // if someone modified it, return the modified buffer. | ||
| 206 | // otherwise return null to mean "no transforms occurred" | ||
| 207 | byte [] result; | ||
| 208 | if ( someoneTouchedTheBytecode ) { | ||
| 209 | result = bufferToUse; | ||
| 210 | } | ||
| 211 | else { | ||
| 212 | result = null; | ||
| 213 | } | ||
| 214 | |||
| 215 | return result; | ||
| 216 | } | ||
| 217 | |||
| 218 | |||
| 219 | int | ||
| 220 | getTransformerCount() { | ||
| 221 | TransformerInfo[] transformerList = getSnapshotTransformerList(); | ||
| 222 | return transformerList.length; | ||
| 223 | } | ||
| 224 | |||
| 225 | boolean | ||
| 226 | setNativeMethodPrefix(ClassFileTransformer transformer, String prefix) { | ||
| 227 | TransformerInfo[] transformerList = getSnapshotTransformerList(); | ||
| 228 | |||
| 229 | for ( int x = 0; x < transformerList.length; x++ ) { | ||
| 230 | TransformerInfo transformerInfo = transformerList[x]; | ||
| 231 | ClassFileTransformer aTransformer = transformerInfo.transformer(); | ||
| 232 | |||
| 233 | if ( aTransformer == transformer ) { | ||
| 234 | transformerInfo.setPrefix(prefix); | ||
| 235 | return true; | ||
| 236 | } | ||
| 237 | } | ||
| 238 | return false; | ||
| 239 | } | ||
| 240 | |||
| 241 | |||
| 242 | String[] | ||
| 243 | getNativeMethodPrefixes() { | ||
| 244 | TransformerInfo[] transformerList = getSnapshotTransformerList(); | ||
| 245 | String[] prefixes = new String[transformerList.length]; | ||
| 246 | |||
| 247 | for ( int x = 0; x < transformerList.length; x++ ) { | ||
| 248 | TransformerInfo transformerInfo = transformerList[x]; | ||
| 249 | prefixes[x] = transformerInfo.getPrefix(); | ||
| 250 | } | ||
| 251 | return prefixes; | ||
| 252 | } | ||
| 253 | } | ||