J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2003-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | package sun.instrument; |
| 28 | |
| 29 | import java.lang.reflect.Method; |
| 30 | import java.lang.reflect.AccessibleObject; |
| 31 | |
| 32 | import java.lang.instrument.ClassFileTransformer; |
| 33 | import java.lang.instrument.ClassDefinition; |
| 34 | import java.lang.instrument.Instrumentation; |
| 35 | |
| 36 | import java.security.AccessController; |
| 37 | import java.security.PrivilegedAction; |
| 38 | import java.security.ProtectionDomain; |
| 39 | |
| 40 | import java.util.jar.JarFile; |
| 41 | |
| 42 | /* |
| 43 | * Copyright 2003 Wily Technology, Inc. |
| 44 | */ |
| 45 | |
| 46 | /** |
| 47 | * The Java side of the JPLIS implementation. Works in concert with a native JVMTI agent |
| 48 | * to implement the JPLIS API set. Provides both the Java API implementation of |
| 49 | * the Instrumentation interface and utility Java routines to support the native code. |
| 50 | * Keeps a pointer to the native data structure in a scalar field to allow native |
| 51 | * processing behind native methods. |
| 52 | */ |
| 53 | public class InstrumentationImpl implements Instrumentation { |
| 54 | private final TransformerManager mTransformerManager; |
| 55 | private TransformerManager mRetransfomableTransformerManager; |
| 56 | // needs to store a native pointer, so use 64 bits |
| 57 | private final long mNativeAgent; |
| 58 | private final boolean mEnvironmentSupportsRedefineClasses; |
| 59 | private volatile boolean mEnvironmentSupportsRetransformClassesKnown; |
| 60 | private volatile boolean mEnvironmentSupportsRetransformClasses; |
| 61 | private final boolean mEnvironmentSupportsNativeMethodPrefix; |
| 62 | |
| 63 | private |
| 64 | InstrumentationImpl(long nativeAgent, |
| 65 | boolean environmentSupportsRedefineClasses, |
| 66 | boolean environmentSupportsNativeMethodPrefix) { |
| 67 | mTransformerManager = new TransformerManager(false); |
| 68 | mRetransfomableTransformerManager = null; |
| 69 | mNativeAgent = nativeAgent; |
| 70 | mEnvironmentSupportsRedefineClasses = environmentSupportsRedefineClasses; |
| 71 | mEnvironmentSupportsRetransformClassesKnown = false; // false = need to ask |
| 72 | mEnvironmentSupportsRetransformClasses = false; // don't know yet |
| 73 | mEnvironmentSupportsNativeMethodPrefix = environmentSupportsNativeMethodPrefix; |
| 74 | } |
| 75 | |
| 76 | public void |
| 77 | addTransformer(ClassFileTransformer transformer) { |
| 78 | addTransformer(transformer, false); |
| 79 | } |
| 80 | |
| 81 | public synchronized void |
| 82 | addTransformer(ClassFileTransformer transformer, boolean canRetransform) { |
| 83 | if (transformer == null) { |
| 84 | throw new NullPointerException("null passed as 'transformer' in addTransformer"); |
| 85 | } |
| 86 | if (canRetransform) { |
| 87 | if (!isRetransformClassesSupported()) { |
| 88 | throw new UnsupportedOperationException( |
| 89 | "adding retransformable transformers is not supported in this environment"); |
| 90 | } |
| 91 | if (mRetransfomableTransformerManager == null) { |
| 92 | mRetransfomableTransformerManager = new TransformerManager(true); |
| 93 | } |
| 94 | mRetransfomableTransformerManager.addTransformer(transformer); |
| 95 | if (mRetransfomableTransformerManager.getTransformerCount() == 1) { |
| 96 | setHasRetransformableTransformers(mNativeAgent, true); |
| 97 | } |
| 98 | } else { |
| 99 | mTransformerManager.addTransformer(transformer); |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | public synchronized boolean |
| 104 | removeTransformer(ClassFileTransformer transformer) { |
| 105 | if (transformer == null) { |
| 106 | throw new NullPointerException("null passed as 'transformer' in removeTransformer"); |
| 107 | } |
| 108 | TransformerManager mgr = findTransformerManager(transformer); |
| 109 | if (mgr != null) { |
| 110 | mgr.removeTransformer(transformer); |
| 111 | if (mgr.isRetransformable() && mgr.getTransformerCount() == 0) { |
| 112 | setHasRetransformableTransformers(mNativeAgent, false); |
| 113 | } |
| 114 | return true; |
| 115 | } |
| 116 | return false; |
| 117 | } |
| 118 | |
| 119 | public boolean |
| 120 | isModifiableClass(Class<?> theClass) { |
| 121 | if (theClass == null) { |
| 122 | throw new NullPointerException( |
| 123 | "null passed as 'theClass' in isModifiableClass"); |
| 124 | } |
| 125 | return isModifiableClass0(mNativeAgent, theClass); |
| 126 | } |
| 127 | |
| 128 | public boolean |
| 129 | isRetransformClassesSupported() { |
| 130 | // ask lazily since there is some overhead |
| 131 | if (!mEnvironmentSupportsRetransformClassesKnown) { |
| 132 | mEnvironmentSupportsRetransformClasses = isRetransformClassesSupported0(mNativeAgent); |
| 133 | mEnvironmentSupportsRetransformClassesKnown = true; |
| 134 | } |
| 135 | return mEnvironmentSupportsRetransformClasses; |
| 136 | } |
| 137 | |
| 138 | public void |
| 139 | retransformClasses(Class<?>[] classes) { |
| 140 | if (!isRetransformClassesSupported()) { |
| 141 | throw new UnsupportedOperationException( |
| 142 | "retransformClasses is not supported in this environment"); |
| 143 | } |
| 144 | retransformClasses0(mNativeAgent, classes); |
| 145 | } |
| 146 | |
| 147 | public boolean |
| 148 | isRedefineClassesSupported() { |
| 149 | return mEnvironmentSupportsRedefineClasses; |
| 150 | } |
| 151 | |
| 152 | public void |
| 153 | redefineClasses(ClassDefinition[] definitions) |
| 154 | throws ClassNotFoundException { |
| 155 | if (!isRedefineClassesSupported()) { |
| 156 | throw new UnsupportedOperationException("redefineClasses is not supported in this environment"); |
| 157 | } |
| 158 | if (definitions == null) { |
| 159 | throw new NullPointerException("null passed as 'definitions' in redefineClasses"); |
| 160 | } |
| 161 | for (int i = 0; i < definitions.length; ++i) { |
| 162 | if (definitions[i] == null) { |
| 163 | throw new NullPointerException("element of 'definitions' is null in redefineClasses"); |
| 164 | } |
| 165 | } |
| 166 | if (definitions.length == 0) { |
| 167 | return; // short-circuit if there are no changes requested |
| 168 | } |
| 169 | |
| 170 | redefineClasses0(mNativeAgent, definitions); |
| 171 | } |
| 172 | |
| 173 | public Class[] |
| 174 | getAllLoadedClasses() { |
| 175 | return getAllLoadedClasses0(mNativeAgent); |
| 176 | } |
| 177 | |
| 178 | public Class[] |
| 179 | getInitiatedClasses(ClassLoader loader) { |
| 180 | return getInitiatedClasses0(mNativeAgent, loader); |
| 181 | } |
| 182 | |
| 183 | public long |
| 184 | getObjectSize(Object objectToSize) { |
| 185 | if (objectToSize == null) { |
| 186 | throw new NullPointerException("null passed as 'objectToSize' in getObjectSize"); |
| 187 | } |
| 188 | return getObjectSize0(mNativeAgent, objectToSize); |
| 189 | } |
| 190 | |
| 191 | public void |
| 192 | appendToBootstrapClassLoaderSearch(JarFile jarfile) { |
| 193 | appendToClassLoaderSearch0(mNativeAgent, jarfile.getName(), true); |
| 194 | } |
| 195 | |
| 196 | public void |
| 197 | appendToSystemClassLoaderSearch(JarFile jarfile) { |
| 198 | appendToClassLoaderSearch0(mNativeAgent, jarfile.getName(), false); |
| 199 | } |
| 200 | |
| 201 | public boolean |
| 202 | isNativeMethodPrefixSupported() { |
| 203 | return mEnvironmentSupportsNativeMethodPrefix; |
| 204 | } |
| 205 | |
| 206 | public synchronized void |
| 207 | setNativeMethodPrefix(ClassFileTransformer transformer, String prefix) { |
| 208 | if (!isNativeMethodPrefixSupported()) { |
| 209 | throw new UnsupportedOperationException( |
| 210 | "setNativeMethodPrefix is not supported in this environment"); |
| 211 | } |
| 212 | if (transformer == null) { |
| 213 | throw new NullPointerException( |
| 214 | "null passed as 'transformer' in setNativeMethodPrefix"); |
| 215 | } |
| 216 | TransformerManager mgr = findTransformerManager(transformer); |
| 217 | if (mgr == null) { |
| 218 | throw new IllegalArgumentException( |
| 219 | "transformer not registered in setNativeMethodPrefix"); |
| 220 | } |
| 221 | mgr.setNativeMethodPrefix(transformer, prefix); |
| 222 | String[] prefixes = mgr.getNativeMethodPrefixes(); |
| 223 | setNativeMethodPrefixes(mNativeAgent, prefixes, mgr.isRetransformable()); |
| 224 | } |
| 225 | |
| 226 | private TransformerManager |
| 227 | findTransformerManager(ClassFileTransformer transformer) { |
| 228 | if (mTransformerManager.includesTransformer(transformer)) { |
| 229 | return mTransformerManager; |
| 230 | } |
| 231 | if (mRetransfomableTransformerManager != null && |
| 232 | mRetransfomableTransformerManager.includesTransformer(transformer)) { |
| 233 | return mRetransfomableTransformerManager; |
| 234 | } |
| 235 | return null; |
| 236 | } |
| 237 | |
| 238 | |
| 239 | /* |
| 240 | * Natives |
| 241 | */ |
| 242 | private native boolean |
| 243 | isModifiableClass0(long nativeAgent, Class<?> theClass); |
| 244 | |
| 245 | private native boolean |
| 246 | isRetransformClassesSupported0(long nativeAgent); |
| 247 | |
| 248 | private native void |
| 249 | setHasRetransformableTransformers(long nativeAgent, boolean has); |
| 250 | |
| 251 | private native void |
| 252 | retransformClasses0(long nativeAgent, Class<?>[] classes); |
| 253 | |
| 254 | private native void |
| 255 | redefineClasses0(long nativeAgent, ClassDefinition[] definitions) |
| 256 | throws ClassNotFoundException; |
| 257 | |
| 258 | private native Class[] |
| 259 | getAllLoadedClasses0(long nativeAgent); |
| 260 | |
| 261 | private native Class[] |
| 262 | getInitiatedClasses0(long nativeAgent, ClassLoader loader); |
| 263 | |
| 264 | private native long |
| 265 | getObjectSize0(long nativeAgent, Object objectToSize); |
| 266 | |
| 267 | private native void |
| 268 | appendToClassLoaderSearch0(long nativeAgent, String jarfile, boolean bootLoader); |
| 269 | |
| 270 | private native void |
| 271 | setNativeMethodPrefixes(long nativeAgent, String[] prefixes, boolean isRetransformable); |
| 272 | |
| 273 | static { |
| 274 | System.loadLibrary("instrument"); |
| 275 | } |
| 276 | |
| 277 | /* |
| 278 | * Internals |
| 279 | */ |
| 280 | |
| 281 | |
| 282 | // Enable or disable Java programming language access checks on a |
| 283 | // reflected object (for example, a method) |
| 284 | private static void setAccessible(final AccessibleObject ao, final boolean accessible) { |
| 285 | AccessController.doPrivileged(new PrivilegedAction<Object>() { |
| 286 | public Object run() { |
| 287 | ao.setAccessible(accessible); |
| 288 | return null; |
| 289 | }}); |
| 290 | } |
| 291 | |
| 292 | // Attempt to load and start an agent |
| 293 | private void |
| 294 | loadClassAndStartAgent( String classname, |
| 295 | String methodname, |
| 296 | String optionsString) |
| 297 | throws Throwable { |
| 298 | |
| 299 | ClassLoader mainAppLoader = ClassLoader.getSystemClassLoader(); |
| 300 | Class<?> javaAgentClass = mainAppLoader.loadClass(classname); |
| 301 | |
| 302 | Method m = null; |
| 303 | NoSuchMethodException firstExc = null; |
| 304 | boolean twoArgAgent = false; |
| 305 | |
| 306 | // The agent class has a premain or agentmain method that has 1 or 2 |
| 307 | // arguments. We first check for a signature of (String, Instrumentation), |
| 308 | // and if not found we check for (String). If neither is found then we |
| 309 | // throw the NoSuchMethodException from the first attempt so that the |
| 310 | // exception text indicates the lookup failed for the 2-arg method |
| 311 | // (same as JDK5.0). |
| 312 | |
| 313 | try { |
| 314 | m = javaAgentClass.getMethod( methodname, |
| 315 | new Class[] { |
| 316 | String.class, |
| 317 | java.lang.instrument.Instrumentation.class |
| 318 | } |
| 319 | ); |
| 320 | twoArgAgent = true; |
| 321 | } catch (NoSuchMethodException x) { |
| 322 | // remember the NoSuchMethodException |
| 323 | firstExc = x; |
| 324 | } |
| 325 | |
| 326 | // check for the 1-arg method |
| 327 | if (m == null) { |
| 328 | try { |
| 329 | m = javaAgentClass.getMethod(methodname, new Class[] { String.class }); |
| 330 | } catch (NoSuchMethodException x) { |
| 331 | // Neither method exists so we throw the first NoSuchMethodException |
| 332 | // as per 5.0 |
| 333 | throw firstExc; |
| 334 | } |
| 335 | } |
| 336 | |
| 337 | // the premain method should not be required to be public, |
| 338 | // make it accessible so we can call it |
| 339 | setAccessible(m, true); |
| 340 | |
| 341 | // invoke the 1 or 2-arg method |
| 342 | if (twoArgAgent) { |
| 343 | m.invoke(null, new Object[] { optionsString, this }); |
| 344 | } else { |
| 345 | m.invoke(null, new Object[] { optionsString }); |
| 346 | } |
| 347 | |
| 348 | // don't let others access a non-public premain method |
| 349 | setAccessible(m, false); |
| 350 | } |
| 351 | |
| 352 | // WARNING: the native code knows the name & signature of this method |
| 353 | private void |
| 354 | loadClassAndCallPremain( String classname, |
| 355 | String optionsString) |
| 356 | throws Throwable { |
| 357 | |
| 358 | loadClassAndStartAgent( classname, "premain", optionsString ); |
| 359 | } |
| 360 | |
| 361 | |
| 362 | // WARNING: the native code knows the name & signature of this method |
| 363 | private void |
| 364 | loadClassAndCallAgentmain( String classname, |
| 365 | String optionsString) |
| 366 | throws Throwable { |
| 367 | |
| 368 | loadClassAndStartAgent( classname, "agentmain", optionsString ); |
| 369 | } |
| 370 | |
| 371 | // WARNING: the native code knows the name & signature of this method |
| 372 | private byte[] |
| 373 | transform( ClassLoader loader, |
| 374 | String classname, |
| 375 | Class classBeingRedefined, |
| 376 | ProtectionDomain protectionDomain, |
| 377 | byte[] classfileBuffer, |
| 378 | boolean isRetransformer) { |
| 379 | TransformerManager mgr = isRetransformer? |
| 380 | mRetransfomableTransformerManager : |
| 381 | mTransformerManager; |
| 382 | if (mgr == null) { |
| 383 | return null; // no manager, no transform |
| 384 | } else { |
| 385 | return mgr.transform( loader, |
| 386 | classname, |
| 387 | classBeingRedefined, |
| 388 | protectionDomain, |
| 389 | classfileBuffer); |
| 390 | } |
| 391 | } |
| 392 | } |