src/share/vm/classfile/classLoaderData.cpp

Wed, 12 Dec 2012 22:41:13 +0100

author
stefank
date
Wed, 12 Dec 2012 22:41:13 +0100
changeset 4353
1b1e16471e46
parent 4304
90273fc0a981
child 4367
c52660592f37
permissions
-rw-r--r--

8005002: Crash because of a raw oop in ClassLoaderData::add_dependency
Summary: Move the handelization of 'last' to a point before the GC might enter.
Reviewed-by: dholmes, sspitsyn, coleenp

coleenp@4037 1 /*
coleenp@4037 2 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
coleenp@4037 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
coleenp@4037 4 *
coleenp@4037 5 * This code is free software; you can redistribute it and/or modify it
coleenp@4037 6 * under the terms of the GNU General Public License version 2 only, as
coleenp@4037 7 * published by the Free Software Foundation.
coleenp@4037 8 *
coleenp@4037 9 * This code is distributed in the hope that it will be useful, but WITHOUT
coleenp@4037 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
coleenp@4037 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
coleenp@4037 12 * version 2 for more details (a copy is included in the LICENSE file that
coleenp@4037 13 * accompanied this code).
coleenp@4037 14 *
coleenp@4037 15 * You should have received a copy of the GNU General Public License version
coleenp@4037 16 * 2 along with this work; if not, write to the Free Software Foundation,
coleenp@4037 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
coleenp@4037 18 *
coleenp@4037 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
coleenp@4037 20 * or visit www.oracle.com if you need additional information or have any
coleenp@4037 21 * questions.
coleenp@4037 22 *
coleenp@4037 23 */
coleenp@4037 24
coleenp@4037 25 // A ClassLoaderData identifies the full set of class types that a class
coleenp@4037 26 // loader's name resolution strategy produces for a given configuration of the
coleenp@4037 27 // class loader.
coleenp@4037 28 // Class types in the ClassLoaderData may be defined by from class file binaries
coleenp@4037 29 // provided by the class loader, or from other class loader it interacts with
coleenp@4037 30 // according to its name resolution strategy.
coleenp@4037 31 //
coleenp@4037 32 // Class loaders that implement a deterministic name resolution strategy
coleenp@4037 33 // (including with respect to their delegation behavior), such as the boot, the
coleenp@4037 34 // extension, and the system loaders of the JDK's built-in class loader
coleenp@4037 35 // hierarchy, always produce the same linkset for a given configuration.
coleenp@4037 36 //
coleenp@4037 37 // ClassLoaderData carries information related to a linkset (e.g.,
coleenp@4037 38 // metaspace holding its klass definitions).
coleenp@4037 39 // The System Dictionary and related data structures (e.g., placeholder table,
coleenp@4037 40 // loader constraints table) as well as the runtime representation of classes
coleenp@4037 41 // only reference ClassLoaderData.
coleenp@4037 42 //
coleenp@4037 43 // Instances of java.lang.ClassLoader holds a pointer to a ClassLoaderData that
coleenp@4037 44 // that represent the loader's "linking domain" in the JVM.
coleenp@4037 45 //
coleenp@4037 46 // The bootstrap loader (represented by NULL) also has a ClassLoaderData,
coleenp@4037 47 // the singleton class the_null_class_loader_data().
coleenp@4037 48
coleenp@4037 49 #include "precompiled.hpp"
coleenp@4037 50 #include "classfile/classLoaderData.hpp"
coleenp@4037 51 #include "classfile/classLoaderData.inline.hpp"
coleenp@4037 52 #include "classfile/javaClasses.hpp"
coleenp@4037 53 #include "classfile/systemDictionary.hpp"
coleenp@4037 54 #include "code/codeCache.hpp"
coleenp@4037 55 #include "memory/metadataFactory.hpp"
coleenp@4037 56 #include "memory/metaspaceShared.hpp"
coleenp@4037 57 #include "prims/jvmtiRedefineClasses.hpp"
coleenp@4037 58 #include "runtime/jniHandles.hpp"
coleenp@4037 59 #include "runtime/mutex.hpp"
coleenp@4037 60 #include "runtime/safepoint.hpp"
coleenp@4037 61 #include "runtime/synchronizer.hpp"
coleenp@4037 62 #include "utilities/growableArray.hpp"
coleenp@4037 63 #include "utilities/ostream.hpp"
coleenp@4037 64
coleenp@4037 65 ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
coleenp@4037 66
coleenp@4037 67 ClassLoaderData::ClassLoaderData(Handle h_class_loader) : _class_loader(h_class_loader()),
coleenp@4304 68 _metaspace(NULL), _unloading(false), _keep_alive(false), _klasses(NULL),
coleenp@4304 69 _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL),
coleenp@4304 70 _next(NULL), _dependencies(NULL),
coleenp@4037 71 _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
coleenp@4037 72 // empty
coleenp@4037 73 }
coleenp@4037 74
coleenp@4304 75 void ClassLoaderData::init_dependencies(TRAPS) {
coleenp@4304 76 // Create empty dependencies array to add to. CMS requires this to be
coleenp@4304 77 // an oop so that it can track additions via card marks. We think.
coleenp@4304 78 _dependencies = (oop)oopFactory::new_objectArray(2, CHECK);
coleenp@4304 79 }
coleenp@4304 80
coleenp@4037 81 bool ClassLoaderData::claim() {
coleenp@4037 82 if (_claimed == 1) {
coleenp@4037 83 return false;
coleenp@4037 84 }
coleenp@4037 85
coleenp@4037 86 return (int) Atomic::cmpxchg(1, &_claimed, 0) == 0;
coleenp@4037 87 }
coleenp@4037 88
coleenp@4037 89 void ClassLoaderData::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
coleenp@4037 90 if (must_claim && !claim()) {
coleenp@4037 91 return;
coleenp@4037 92 }
coleenp@4037 93
coleenp@4037 94 f->do_oop(&_class_loader);
coleenp@4304 95 f->do_oop(&_dependencies);
coleenp@4037 96 _handles->oops_do(f);
coleenp@4037 97 if (klass_closure != NULL) {
coleenp@4037 98 classes_do(klass_closure);
coleenp@4037 99 }
coleenp@4037 100 }
coleenp@4037 101
coleenp@4037 102 void ClassLoaderData::classes_do(KlassClosure* klass_closure) {
coleenp@4037 103 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
coleenp@4037 104 klass_closure->do_klass(k);
coleenp@4037 105 }
coleenp@4037 106 }
coleenp@4037 107
coleenp@4037 108 void ClassLoaderData::classes_do(void f(InstanceKlass*)) {
coleenp@4037 109 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
coleenp@4037 110 if (k->oop_is_instance()) {
coleenp@4037 111 f(InstanceKlass::cast(k));
coleenp@4037 112 }
coleenp@4037 113 }
coleenp@4037 114 }
coleenp@4037 115
coleenp@4037 116 void ClassLoaderData::record_dependency(Klass* k, TRAPS) {
coleenp@4037 117 ClassLoaderData * const from_cld = this;
coleenp@4037 118 ClassLoaderData * const to_cld = k->class_loader_data();
coleenp@4037 119
coleenp@4304 120 // Dependency to the null class loader data doesn't need to be recorded
coleenp@4304 121 // because the null class loader data never goes away.
coleenp@4304 122 if (to_cld->is_the_null_class_loader_data()) {
coleenp@4037 123 return;
coleenp@4037 124 }
coleenp@4037 125
coleenp@4304 126 oop to;
coleenp@4304 127 if (to_cld->is_anonymous()) {
coleenp@4304 128 // Anonymous class dependencies are through the mirror.
coleenp@4304 129 to = k->java_mirror();
coleenp@4304 130 } else {
coleenp@4304 131 to = to_cld->class_loader();
coleenp@4037 132
coleenp@4304 133 // If from_cld is anonymous, even if it's class_loader is a parent of 'to'
coleenp@4304 134 // we still have to add it. The class_loader won't keep from_cld alive.
coleenp@4304 135 if (!from_cld->is_anonymous()) {
coleenp@4304 136 // Check that this dependency isn't from the same or parent class_loader
coleenp@4304 137 oop from = from_cld->class_loader();
coleenp@4304 138
coleenp@4304 139 oop curr = from;
coleenp@4304 140 while (curr != NULL) {
coleenp@4304 141 if (curr == to) {
coleenp@4304 142 return; // this class loader is in the parent list, no need to add it.
coleenp@4304 143 }
coleenp@4304 144 curr = java_lang_ClassLoader::parent(curr);
coleenp@4304 145 }
coleenp@4037 146 }
coleenp@4037 147 }
coleenp@4037 148
coleenp@4037 149 // It's a dependency we won't find through GC, add it. This is relatively rare
coleenp@4304 150 // Must handle over GC point.
coleenp@4304 151 Handle dependency(THREAD, to);
coleenp@4304 152 from_cld->add_dependency(dependency, CHECK);
coleenp@4037 153 }
coleenp@4037 154
coleenp@4037 155
coleenp@4304 156 void ClassLoaderData::add_dependency(Handle dependency, TRAPS) {
coleenp@4304 157 // Check first if this dependency is already in the list.
coleenp@4304 158 // Save a pointer to the last to add to under the lock.
coleenp@4304 159 objArrayOop ok = (objArrayOop)_dependencies;
coleenp@4304 160 objArrayOop last = NULL;
coleenp@4037 161 while (ok != NULL) {
coleenp@4304 162 last = ok;
coleenp@4304 163 if (ok->obj_at(0) == dependency()) {
coleenp@4304 164 // Don't need to add it
coleenp@4304 165 return;
coleenp@4037 166 }
coleenp@4037 167 ok = (objArrayOop)ok->obj_at(1);
coleenp@4037 168 }
coleenp@4304 169
stefank@4353 170 // Must handle over GC points
stefank@4353 171 assert (last != NULL, "dependencies should be initialized");
stefank@4353 172 objArrayHandle last_handle(THREAD, last);
stefank@4353 173
coleenp@4304 174 // Create a new dependency node with fields for (class_loader or mirror, next)
coleenp@4304 175 objArrayOop deps = oopFactory::new_objectArray(2, CHECK);
coleenp@4304 176 deps->obj_at_put(0, dependency());
coleenp@4304 177
stefank@4353 178 // Must handle over GC points
coleenp@4304 179 objArrayHandle new_dependency(THREAD, deps);
coleenp@4304 180
coleenp@4304 181 // Add the dependency under lock
coleenp@4304 182 locked_add_dependency(last_handle, new_dependency);
coleenp@4037 183 }
coleenp@4037 184
coleenp@4304 185 void ClassLoaderData::locked_add_dependency(objArrayHandle last_handle,
coleenp@4304 186 objArrayHandle new_dependency) {
coleenp@4304 187
coleenp@4304 188 // Have to lock and put the new dependency on the end of the dependency
coleenp@4304 189 // array so the card mark for CMS sees that this dependency is new.
coleenp@4304 190 // Can probably do this lock free with some effort.
coleenp@4304 191 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
coleenp@4304 192
coleenp@4304 193 oop loader_or_mirror = new_dependency->obj_at(0);
coleenp@4304 194
coleenp@4304 195 // Since the dependencies are only added, add to the end.
coleenp@4304 196 objArrayOop end = last_handle();
coleenp@4304 197 objArrayOop last = NULL;
coleenp@4304 198 while (end != NULL) {
coleenp@4304 199 last = end;
coleenp@4304 200 // check again if another thread added it to the end.
coleenp@4304 201 if (end->obj_at(0) == loader_or_mirror) {
coleenp@4304 202 // Don't need to add it
coleenp@4304 203 return;
coleenp@4304 204 }
coleenp@4304 205 end = (objArrayOop)end->obj_at(1);
coleenp@4037 206 }
coleenp@4304 207 assert (last != NULL, "dependencies should be initialized");
coleenp@4304 208 // fill in the first element with the oop in new_dependency.
coleenp@4304 209 if (last->obj_at(0) == NULL) {
coleenp@4304 210 last->obj_at_put(0, new_dependency->obj_at(0));
coleenp@4304 211 } else {
coleenp@4304 212 last->obj_at_put(1, new_dependency());
coleenp@4037 213 }
coleenp@4037 214 }
coleenp@4037 215
coleenp@4037 216 void ClassLoaderDataGraph::clear_claimed_marks() {
coleenp@4037 217 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4037 218 cld->clear_claimed();
coleenp@4037 219 }
coleenp@4037 220 }
coleenp@4037 221
coleenp@4037 222 void ClassLoaderData::add_class(Klass* k) {
coleenp@4037 223 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
coleenp@4037 224 Klass* old_value = _klasses;
coleenp@4037 225 k->set_next_link(old_value);
coleenp@4037 226 // link the new item into the list
coleenp@4037 227 _klasses = k;
coleenp@4037 228
coleenp@4304 229 if (TraceClassLoaderData && Verbose && k->class_loader_data() != NULL) {
coleenp@4037 230 ResourceMark rm;
coleenp@4037 231 tty->print_cr("[TraceClassLoaderData] Adding k: " PTR_FORMAT " %s to CLD: "
coleenp@4037 232 PTR_FORMAT " loader: " PTR_FORMAT " %s",
coleenp@4037 233 k,
coleenp@4037 234 k->external_name(),
coleenp@4037 235 k->class_loader_data(),
coleenp@4037 236 k->class_loader(),
coleenp@4304 237 loader_name());
coleenp@4037 238 }
coleenp@4037 239 }
coleenp@4037 240
coleenp@4037 241 // This is called by InstanceKlass::deallocate_contents() to remove the
coleenp@4037 242 // scratch_class for redefine classes. We need a lock because there it may not
coleenp@4037 243 // be called at a safepoint if there's an error.
coleenp@4037 244 void ClassLoaderData::remove_class(Klass* scratch_class) {
coleenp@4037 245 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
coleenp@4037 246 Klass* prev = NULL;
coleenp@4037 247 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
coleenp@4037 248 if (k == scratch_class) {
coleenp@4037 249 if (prev == NULL) {
coleenp@4037 250 _klasses = k->next_link();
coleenp@4037 251 } else {
coleenp@4037 252 Klass* next = k->next_link();
coleenp@4037 253 prev->set_next_link(next);
coleenp@4037 254 }
coleenp@4037 255 return;
coleenp@4037 256 }
coleenp@4037 257 prev = k;
coleenp@4037 258 }
coleenp@4037 259 ShouldNotReachHere(); // should have found this class!!
coleenp@4037 260 }
coleenp@4037 261
coleenp@4304 262
coleenp@4304 263 bool ClassLoaderData::is_anonymous() const {
coleenp@4304 264 Klass* k = _klasses;
coleenp@4304 265 return (_keep_alive || (k != NULL && k->oop_is_instance() &&
coleenp@4304 266 InstanceKlass::cast(k)->is_anonymous()));
coleenp@4304 267 }
coleenp@4304 268
coleenp@4304 269 void ClassLoaderData::unload() {
coleenp@4304 270 _unloading = true;
coleenp@4304 271
coleenp@4304 272 if (TraceClassLoaderData) {
coleenp@4304 273 ResourceMark rm;
coleenp@4304 274 tty->print("[ClassLoaderData: unload loader data "PTR_FORMAT, this);
coleenp@4304 275 tty->print(" for instance "PTR_FORMAT" of %s", class_loader(),
coleenp@4304 276 loader_name());
coleenp@4304 277 if (is_anonymous()) {
coleenp@4304 278 tty->print(" for anonymous class "PTR_FORMAT " ", _klasses);
coleenp@4304 279 }
coleenp@4304 280 tty->print_cr("]");
coleenp@4304 281 }
coleenp@4304 282 }
coleenp@4304 283
coleenp@4304 284 bool ClassLoaderData::is_alive(BoolObjectClosure* is_alive_closure) const {
coleenp@4304 285 bool alive =
coleenp@4304 286 is_anonymous() ?
coleenp@4304 287 is_alive_closure->do_object_b(_klasses->java_mirror()) :
coleenp@4304 288 class_loader() == NULL || is_alive_closure->do_object_b(class_loader());
coleenp@4304 289 assert(!alive || claimed(), "must be claimed");
coleenp@4304 290 return alive;
coleenp@4304 291 }
coleenp@4304 292
coleenp@4304 293
coleenp@4037 294 ClassLoaderData::~ClassLoaderData() {
coleenp@4037 295 Metaspace *m = _metaspace;
coleenp@4037 296 if (m != NULL) {
coleenp@4037 297 _metaspace = NULL;
coleenp@4037 298 // release the metaspace
coleenp@4037 299 delete m;
coleenp@4037 300 // release the handles
coleenp@4037 301 if (_handles != NULL) {
coleenp@4037 302 JNIHandleBlock::release_block(_handles);
coleenp@4037 303 _handles = NULL;
coleenp@4037 304 }
coleenp@4037 305 }
coleenp@4037 306
coleenp@4037 307 // Clear all the JNI handles for methods
coleenp@4037 308 // These aren't deallocated and are going to look like a leak, but that's
coleenp@4037 309 // needed because we can't really get rid of jmethodIDs because we don't
coleenp@4037 310 // know when native code is going to stop using them. The spec says that
coleenp@4037 311 // they're "invalid" but existing programs likely rely on their being
coleenp@4037 312 // NULL after class unloading.
coleenp@4037 313 if (_jmethod_ids != NULL) {
coleenp@4037 314 Method::clear_jmethod_ids(this);
coleenp@4037 315 }
coleenp@4037 316 // Delete lock
coleenp@4037 317 delete _metaspace_lock;
coleenp@4037 318
coleenp@4037 319 // Delete free list
coleenp@4037 320 if (_deallocate_list != NULL) {
coleenp@4037 321 delete _deallocate_list;
coleenp@4037 322 }
coleenp@4037 323 }
coleenp@4037 324
coleenp@4037 325 Metaspace* ClassLoaderData::metaspace_non_null() {
coleenp@4037 326 // If the metaspace has not been allocated, create a new one. Might want
coleenp@4037 327 // to create smaller arena for Reflection class loaders also.
coleenp@4037 328 // The reason for the delayed allocation is because some class loaders are
coleenp@4037 329 // simply for delegating with no metadata of their own.
coleenp@4037 330 if (_metaspace == NULL) {
coleenp@4037 331 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
coleenp@4037 332 // Check again if metaspace has been allocated while we were getting this lock.
coleenp@4037 333 if (_metaspace != NULL) {
coleenp@4037 334 return _metaspace;
coleenp@4037 335 }
coleenp@4304 336 if (this == the_null_class_loader_data()) {
coleenp@4304 337 assert (class_loader() == NULL, "Must be");
coleenp@4037 338 size_t word_size = Metaspace::first_chunk_word_size();
coleenp@4037 339 set_metaspace(new Metaspace(_metaspace_lock, word_size));
coleenp@4037 340 } else {
coleenp@4037 341 set_metaspace(new Metaspace(_metaspace_lock)); // default size for now.
coleenp@4037 342 }
coleenp@4037 343 }
coleenp@4037 344 return _metaspace;
coleenp@4037 345 }
coleenp@4037 346
coleenp@4037 347 JNIHandleBlock* ClassLoaderData::handles() const { return _handles; }
coleenp@4037 348 void ClassLoaderData::set_handles(JNIHandleBlock* handles) { _handles = handles; }
coleenp@4037 349
coleenp@4037 350 jobject ClassLoaderData::add_handle(Handle h) {
coleenp@4037 351 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
coleenp@4037 352 if (handles() == NULL) {
coleenp@4037 353 set_handles(JNIHandleBlock::allocate_block());
coleenp@4037 354 }
coleenp@4037 355 return handles()->allocate_handle(h());
coleenp@4037 356 }
coleenp@4037 357
coleenp@4037 358 // Add this metadata pointer to be freed when it's safe. This is only during
coleenp@4037 359 // class unloading because Handles might point to this metadata field.
coleenp@4037 360 void ClassLoaderData::add_to_deallocate_list(Metadata* m) {
coleenp@4037 361 // Metadata in shared region isn't deleted.
coleenp@4037 362 if (!m->is_shared()) {
coleenp@4037 363 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
coleenp@4037 364 if (_deallocate_list == NULL) {
coleenp@4037 365 _deallocate_list = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(100, true);
coleenp@4037 366 }
coleenp@4037 367 _deallocate_list->append_if_missing(m);
coleenp@4037 368 }
coleenp@4037 369 }
coleenp@4037 370
coleenp@4037 371 // Deallocate free metadata on the free list. How useful the PermGen was!
coleenp@4037 372 void ClassLoaderData::free_deallocate_list() {
coleenp@4037 373 // Don't need lock, at safepoint
coleenp@4037 374 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
coleenp@4037 375 if (_deallocate_list == NULL) {
coleenp@4037 376 return;
coleenp@4037 377 }
coleenp@4037 378 // Go backwards because this removes entries that are freed.
coleenp@4037 379 for (int i = _deallocate_list->length() - 1; i >= 0; i--) {
coleenp@4037 380 Metadata* m = _deallocate_list->at(i);
coleenp@4037 381 if (!m->on_stack()) {
coleenp@4037 382 _deallocate_list->remove_at(i);
coleenp@4037 383 // There are only three types of metadata that we deallocate directly.
coleenp@4037 384 // Cast them so they can be used by the template function.
coleenp@4037 385 if (m->is_method()) {
coleenp@4037 386 MetadataFactory::free_metadata(this, (Method*)m);
coleenp@4037 387 } else if (m->is_constantPool()) {
coleenp@4037 388 MetadataFactory::free_metadata(this, (ConstantPool*)m);
coleenp@4037 389 } else if (m->is_klass()) {
coleenp@4037 390 MetadataFactory::free_metadata(this, (InstanceKlass*)m);
coleenp@4037 391 } else {
coleenp@4037 392 ShouldNotReachHere();
coleenp@4037 393 }
coleenp@4037 394 }
coleenp@4037 395 }
coleenp@4037 396 }
coleenp@4037 397
coleenp@4304 398 // These anonymous class loaders are to contain classes used for JSR292
coleenp@4304 399 ClassLoaderData* ClassLoaderData::anonymous_class_loader_data(oop loader, TRAPS) {
coleenp@4304 400 // Add a new class loader data to the graph.
coleenp@4304 401 ClassLoaderData* cld = ClassLoaderDataGraph::add(NULL, loader, CHECK_NULL);
coleenp@4304 402 return cld;
coleenp@4037 403 }
coleenp@4037 404
coleenp@4304 405 const char* ClassLoaderData::loader_name() {
coleenp@4304 406 // Handles null class loader
coleenp@4304 407 return SystemDictionary::loader_name(class_loader());
coleenp@4304 408 }
coleenp@4304 409
coleenp@4304 410 #ifndef PRODUCT
coleenp@4037 411 // Define to dump klasses
coleenp@4037 412 #undef CLD_DUMP_KLASSES
coleenp@4037 413
coleenp@4037 414 void ClassLoaderData::dump(outputStream * const out) {
coleenp@4037 415 ResourceMark rm;
coleenp@4037 416 out->print("ClassLoaderData CLD: "PTR_FORMAT", loader: "PTR_FORMAT", loader_klass: "PTR_FORMAT" %s {",
coleenp@4037 417 this, class_loader(),
coleenp@4304 418 class_loader() != NULL ? class_loader()->klass() : NULL, loader_name());
coleenp@4037 419 if (claimed()) out->print(" claimed ");
coleenp@4037 420 if (is_unloading()) out->print(" unloading ");
coleenp@4037 421 out->print(" handles " INTPTR_FORMAT, handles());
coleenp@4037 422 out->cr();
coleenp@4037 423 if (metaspace_or_null() != NULL) {
coleenp@4037 424 out->print_cr("metaspace: " PTR_FORMAT, metaspace_or_null());
coleenp@4037 425 metaspace_or_null()->dump(out);
coleenp@4037 426 } else {
coleenp@4037 427 out->print_cr("metaspace: NULL");
coleenp@4037 428 }
coleenp@4037 429
coleenp@4037 430 #ifdef CLD_DUMP_KLASSES
coleenp@4037 431 if (Verbose) {
coleenp@4037 432 ResourceMark rm;
coleenp@4037 433 Klass* k = _klasses;
coleenp@4037 434 while (k != NULL) {
coleenp@4037 435 out->print_cr("klass "PTR_FORMAT", %s, CT: %d, MUT: %d", k, k->name()->as_C_string(),
coleenp@4037 436 k->has_modified_oops(), k->has_accumulated_modified_oops());
coleenp@4037 437 k = k->next_link();
coleenp@4037 438 }
coleenp@4037 439 }
coleenp@4037 440 #endif // CLD_DUMP_KLASSES
coleenp@4037 441 #undef CLD_DUMP_KLASSES
coleenp@4037 442 if (_jmethod_ids != NULL) {
coleenp@4037 443 Method::print_jmethod_ids(this, out);
coleenp@4037 444 }
coleenp@4037 445 out->print_cr("}");
coleenp@4037 446 }
coleenp@4037 447 #endif // PRODUCT
coleenp@4037 448
coleenp@4037 449 void ClassLoaderData::verify() {
coleenp@4037 450 oop cl = class_loader();
coleenp@4037 451
coleenp@4304 452 guarantee(this == class_loader_data(cl) || is_anonymous(), "Must be the same");
coleenp@4304 453 guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data() || is_anonymous(), "must be");
coleenp@4037 454
coleenp@4037 455 // Verify the integrity of the allocated space.
coleenp@4037 456 if (metaspace_or_null() != NULL) {
coleenp@4037 457 metaspace_or_null()->verify();
coleenp@4037 458 }
coleenp@4037 459
coleenp@4037 460 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
coleenp@4037 461 guarantee(k->class_loader_data() == this, "Must be the same");
coleenp@4037 462 k->verify();
coleenp@4037 463 }
coleenp@4037 464 }
coleenp@4037 465
coleenp@4304 466
coleenp@4037 467 // GC root of class loader data created.
coleenp@4037 468 ClassLoaderData* ClassLoaderDataGraph::_head = NULL;
coleenp@4037 469 ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL;
coleenp@4037 470 ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL;
coleenp@4037 471
coleenp@4037 472
coleenp@4037 473 // Add a new class loader data node to the list. Assign the newly created
coleenp@4037 474 // ClassLoaderData into the java/lang/ClassLoader object as a hidden field
coleenp@4304 475 ClassLoaderData* ClassLoaderDataGraph::add(ClassLoaderData** cld_addr, Handle loader, TRAPS) {
coleenp@4037 476 // Not assigned a class loader data yet.
coleenp@4037 477 // Create one.
coleenp@4037 478 ClassLoaderData* *list_head = &_head;
coleenp@4037 479 ClassLoaderData* next = _head;
coleenp@4304 480 ClassLoaderData* cld = new ClassLoaderData(loader);
coleenp@4037 481
coleenp@4304 482 if (cld_addr != NULL) {
coleenp@4304 483 // First, Atomically set it
coleenp@4304 484 ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL);
coleenp@4304 485 if (old != NULL) {
coleenp@4304 486 delete cld;
coleenp@4304 487 // Returns the data.
coleenp@4304 488 return old;
coleenp@4304 489 }
coleenp@4304 490 } else {
coleenp@4304 491 // Disallow unloading for this CLD during initialization if there is no
coleenp@4304 492 // class_loader oop to link this to.
coleenp@4304 493 cld->set_keep_alive(true);
coleenp@4037 494 }
coleenp@4037 495
coleenp@4037 496 // We won the race, and therefore the task of adding the data to the list of
coleenp@4037 497 // class loader data
coleenp@4037 498 do {
coleenp@4037 499 cld->set_next(next);
coleenp@4037 500 ClassLoaderData* exchanged = (ClassLoaderData*)Atomic::cmpxchg_ptr(cld, list_head, next);
coleenp@4037 501 if (exchanged == next) {
coleenp@4037 502 if (TraceClassLoaderData) {
coleenp@4304 503 ResourceMark rm;
coleenp@4037 504 tty->print("[ClassLoaderData: ");
coleenp@4037 505 tty->print("create class loader data "PTR_FORMAT, cld);
coleenp@4304 506 tty->print(" for instance "PTR_FORMAT" of %s", cld->class_loader(),
coleenp@4304 507 cld->loader_name());
coleenp@4037 508 tty->print_cr("]");
coleenp@4037 509 }
coleenp@4304 510 // Create dependencies after the CLD is added to the list. Otherwise,
coleenp@4304 511 // the GC GC will not find the CLD and the _class_loader field will
coleenp@4304 512 // not be updated.
coleenp@4304 513 cld->init_dependencies(CHECK_NULL);
coleenp@4037 514 return cld;
coleenp@4037 515 }
coleenp@4037 516 next = exchanged;
coleenp@4037 517 } while (true);
coleenp@4304 518
coleenp@4037 519 }
coleenp@4037 520
coleenp@4037 521 void ClassLoaderDataGraph::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
coleenp@4037 522 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4037 523 cld->oops_do(f, klass_closure, must_claim);
coleenp@4037 524 }
coleenp@4037 525 }
coleenp@4037 526
coleenp@4304 527 void ClassLoaderDataGraph::keep_alive_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
coleenp@4304 528 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4304 529 if (cld->keep_alive()) {
coleenp@4304 530 cld->oops_do(f, klass_closure, must_claim);
coleenp@4304 531 }
coleenp@4304 532 }
coleenp@4304 533 }
coleenp@4304 534
coleenp@4037 535 void ClassLoaderDataGraph::always_strong_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
coleenp@4037 536 if (ClassUnloading) {
coleenp@4037 537 ClassLoaderData::the_null_class_loader_data()->oops_do(f, klass_closure, must_claim);
coleenp@4304 538 // keep any special CLDs alive.
coleenp@4304 539 ClassLoaderDataGraph::keep_alive_oops_do(f, klass_closure, must_claim);
coleenp@4037 540 } else {
coleenp@4037 541 ClassLoaderDataGraph::oops_do(f, klass_closure, must_claim);
coleenp@4037 542 }
coleenp@4037 543 }
coleenp@4037 544
coleenp@4037 545 void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) {
coleenp@4037 546 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4037 547 cld->classes_do(klass_closure);
coleenp@4037 548 }
coleenp@4037 549 }
coleenp@4037 550
coleenp@4037 551 GrowableArray<ClassLoaderData*>* ClassLoaderDataGraph::new_clds() {
coleenp@4037 552 assert(_head == NULL || _saved_head != NULL, "remember_new_clds(true) not called?");
coleenp@4037 553
coleenp@4037 554 GrowableArray<ClassLoaderData*>* array = new GrowableArray<ClassLoaderData*>();
coleenp@4037 555
coleenp@4037 556 // The CLDs in [_head, _saved_head] were all added during last call to remember_new_clds(true);
coleenp@4037 557 ClassLoaderData* curr = _head;
coleenp@4037 558 while (curr != _saved_head) {
coleenp@4037 559 if (!curr->claimed()) {
coleenp@4037 560 array->push(curr);
coleenp@4037 561
coleenp@4037 562 if (TraceClassLoaderData) {
coleenp@4037 563 tty->print("[ClassLoaderData] found new CLD: ");
coleenp@4037 564 curr->print_value_on(tty);
coleenp@4037 565 tty->cr();
coleenp@4037 566 }
coleenp@4037 567 }
coleenp@4037 568
coleenp@4037 569 curr = curr->_next;
coleenp@4037 570 }
coleenp@4037 571
coleenp@4037 572 return array;
coleenp@4037 573 }
coleenp@4037 574
coleenp@4037 575 #ifndef PRODUCT
coleenp@4037 576 // for debugging and hsfind(x)
coleenp@4037 577 bool ClassLoaderDataGraph::contains(address x) {
coleenp@4037 578 // I think we need the _metaspace_lock taken here because the class loader
coleenp@4037 579 // data graph could be changing while we are walking it (new entries added,
coleenp@4037 580 // new entries being unloaded, etc).
coleenp@4037 581 if (DumpSharedSpaces) {
coleenp@4037 582 // There are only two metaspaces to worry about.
coleenp@4037 583 ClassLoaderData* ncld = ClassLoaderData::the_null_class_loader_data();
coleenp@4037 584 return (ncld->ro_metaspace()->contains(x) || ncld->rw_metaspace()->contains(x));
coleenp@4037 585 }
coleenp@4037 586
coleenp@4037 587 if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(x)) {
coleenp@4037 588 return true;
coleenp@4037 589 }
coleenp@4037 590
coleenp@4037 591 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
coleenp@4037 592 if (cld->metaspace_or_null() != NULL && cld->metaspace_or_null()->contains(x)) {
coleenp@4037 593 return true;
coleenp@4037 594 }
coleenp@4037 595 }
coleenp@4037 596
coleenp@4037 597 // Could also be on an unloading list which is okay, ie. still allocated
coleenp@4037 598 // for a little while.
coleenp@4037 599 for (ClassLoaderData* ucld = _unloading; ucld != NULL; ucld = ucld->next()) {
coleenp@4037 600 if (ucld->metaspace_or_null() != NULL && ucld->metaspace_or_null()->contains(x)) {
coleenp@4037 601 return true;
coleenp@4037 602 }
coleenp@4037 603 }
coleenp@4037 604 return false;
coleenp@4037 605 }
coleenp@4037 606
coleenp@4037 607 bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) {
coleenp@4037 608 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
coleenp@4037 609 if (loader_data == data) {
coleenp@4037 610 return true;
coleenp@4037 611 }
coleenp@4037 612 }
coleenp@4037 613
coleenp@4037 614 return false;
coleenp@4037 615 }
coleenp@4037 616 #endif // PRODUCT
coleenp@4037 617
coleenp@4304 618
coleenp@4037 619 // Move class loader data from main list to the unloaded list for unloading
coleenp@4037 620 // and deallocation later.
coleenp@4304 621 bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure) {
coleenp@4037 622 ClassLoaderData* data = _head;
coleenp@4037 623 ClassLoaderData* prev = NULL;
coleenp@4037 624 bool seen_dead_loader = false;
coleenp@4037 625 // mark metadata seen on the stack and code cache so we can delete
coleenp@4037 626 // unneeded entries.
coleenp@4037 627 bool has_redefined_a_class = JvmtiExport::has_redefined_a_class();
coleenp@4037 628 MetadataOnStackMark md_on_stack;
coleenp@4037 629 while (data != NULL) {
coleenp@4304 630 if (data->keep_alive() || data->is_alive(is_alive_closure)) {
coleenp@4037 631 if (has_redefined_a_class) {
coleenp@4037 632 data->classes_do(InstanceKlass::purge_previous_versions);
coleenp@4037 633 }
coleenp@4037 634 data->free_deallocate_list();
coleenp@4037 635 prev = data;
coleenp@4037 636 data = data->next();
coleenp@4037 637 continue;
coleenp@4037 638 }
coleenp@4037 639 seen_dead_loader = true;
coleenp@4037 640 ClassLoaderData* dead = data;
coleenp@4304 641 dead->unload();
coleenp@4037 642 data = data->next();
coleenp@4037 643 // Remove from loader list.
coleenp@4037 644 if (prev != NULL) {
coleenp@4037 645 prev->set_next(data);
coleenp@4037 646 } else {
coleenp@4037 647 assert(dead == _head, "sanity check");
coleenp@4037 648 _head = data;
coleenp@4037 649 }
coleenp@4037 650 dead->set_next(_unloading);
coleenp@4037 651 _unloading = dead;
coleenp@4037 652 }
coleenp@4037 653 return seen_dead_loader;
coleenp@4037 654 }
coleenp@4037 655
coleenp@4037 656 void ClassLoaderDataGraph::purge() {
coleenp@4037 657 ClassLoaderData* list = _unloading;
coleenp@4037 658 _unloading = NULL;
coleenp@4037 659 ClassLoaderData* next = list;
coleenp@4037 660 while (next != NULL) {
coleenp@4037 661 ClassLoaderData* purge_me = next;
coleenp@4037 662 next = purge_me->next();
coleenp@4037 663 delete purge_me;
coleenp@4037 664 }
coleenp@4037 665 }
coleenp@4037 666
coleenp@4037 667 // CDS support
coleenp@4037 668
coleenp@4037 669 // Global metaspaces for writing information to the shared archive. When
coleenp@4037 670 // application CDS is supported, we may need one per metaspace, so this
coleenp@4037 671 // sort of looks like it.
coleenp@4037 672 Metaspace* ClassLoaderData::_ro_metaspace = NULL;
coleenp@4037 673 Metaspace* ClassLoaderData::_rw_metaspace = NULL;
coleenp@4037 674 static bool _shared_metaspaces_initialized = false;
coleenp@4037 675
coleenp@4037 676 // Initialize shared metaspaces (change to call from somewhere not lazily)
coleenp@4037 677 void ClassLoaderData::initialize_shared_metaspaces() {
coleenp@4037 678 assert(DumpSharedSpaces, "only use this for dumping shared spaces");
coleenp@4037 679 assert(this == ClassLoaderData::the_null_class_loader_data(),
coleenp@4037 680 "only supported for null loader data for now");
coleenp@4037 681 assert (!_shared_metaspaces_initialized, "only initialize once");
coleenp@4037 682 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
coleenp@4037 683 _ro_metaspace = new Metaspace(_metaspace_lock, SharedReadOnlySize/wordSize);
coleenp@4037 684 _rw_metaspace = new Metaspace(_metaspace_lock, SharedReadWriteSize/wordSize);
coleenp@4037 685 _shared_metaspaces_initialized = true;
coleenp@4037 686 }
coleenp@4037 687
coleenp@4037 688 Metaspace* ClassLoaderData::ro_metaspace() {
coleenp@4037 689 assert(_ro_metaspace != NULL, "should already be initialized");
coleenp@4037 690 return _ro_metaspace;
coleenp@4037 691 }
coleenp@4037 692
coleenp@4037 693 Metaspace* ClassLoaderData::rw_metaspace() {
coleenp@4037 694 assert(_rw_metaspace != NULL, "should already be initialized");
coleenp@4037 695 return _rw_metaspace;
coleenp@4037 696 }
coleenp@4037 697
coleenp@4037 698
coleenp@4037 699 ClassLoaderDataGraphMetaspaceIterator::ClassLoaderDataGraphMetaspaceIterator() {
coleenp@4037 700 _data = ClassLoaderDataGraph::_head;
coleenp@4037 701 }
coleenp@4037 702
coleenp@4037 703 ClassLoaderDataGraphMetaspaceIterator::~ClassLoaderDataGraphMetaspaceIterator() {}
coleenp@4037 704
coleenp@4037 705 #ifndef PRODUCT
coleenp@4037 706 // callable from debugger
coleenp@4037 707 extern "C" int print_loader_data_graph() {
coleenp@4037 708 ClassLoaderDataGraph::dump_on(tty);
coleenp@4037 709 return 0;
coleenp@4037 710 }
coleenp@4037 711
coleenp@4037 712 void ClassLoaderDataGraph::verify() {
coleenp@4037 713 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
coleenp@4037 714 data->verify();
coleenp@4037 715 }
coleenp@4037 716 }
coleenp@4037 717
coleenp@4037 718 void ClassLoaderDataGraph::dump_on(outputStream * const out) {
coleenp@4037 719 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
coleenp@4037 720 data->dump(out);
coleenp@4037 721 }
coleenp@4037 722 MetaspaceAux::dump(out);
coleenp@4037 723 }
coleenp@4037 724
coleenp@4037 725 void ClassLoaderData::print_value_on(outputStream* out) const {
coleenp@4037 726 if (class_loader() == NULL) {
coleenp@4037 727 out->print_cr("NULL class_loader");
coleenp@4037 728 } else {
coleenp@4037 729 out->print("class loader "PTR_FORMAT, this);
coleenp@4037 730 class_loader()->print_value_on(out);
coleenp@4037 731 }
coleenp@4037 732 }
coleenp@4037 733 #endif // PRODUCT

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