Fri, 12 Apr 2013 12:22:59 -0700
8011933: add number of classes, methods and time spent to CompileTheWorld
Reviewed-by: jrose, kvn
1 /*
2 * Copyright (c) 2012, 2013, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 // A ClassLoaderData identifies the full set of class types that a class
26 // loader's name resolution strategy produces for a given configuration of the
27 // class loader.
28 // Class types in the ClassLoaderData may be defined by from class file binaries
29 // provided by the class loader, or from other class loader it interacts with
30 // according to its name resolution strategy.
31 //
32 // Class loaders that implement a deterministic name resolution strategy
33 // (including with respect to their delegation behavior), such as the boot, the
34 // extension, and the system loaders of the JDK's built-in class loader
35 // hierarchy, always produce the same linkset for a given configuration.
36 //
37 // ClassLoaderData carries information related to a linkset (e.g.,
38 // metaspace holding its klass definitions).
39 // The System Dictionary and related data structures (e.g., placeholder table,
40 // loader constraints table) as well as the runtime representation of classes
41 // only reference ClassLoaderData.
42 //
43 // Instances of java.lang.ClassLoader holds a pointer to a ClassLoaderData that
44 // that represent the loader's "linking domain" in the JVM.
45 //
46 // The bootstrap loader (represented by NULL) also has a ClassLoaderData,
47 // the singleton class the_null_class_loader_data().
49 #include "precompiled.hpp"
50 #include "classfile/classLoaderData.hpp"
51 #include "classfile/classLoaderData.inline.hpp"
52 #include "classfile/javaClasses.hpp"
53 #include "classfile/metadataOnStackMark.hpp"
54 #include "classfile/systemDictionary.hpp"
55 #include "code/codeCache.hpp"
56 #include "memory/metadataFactory.hpp"
57 #include "memory/metaspaceShared.hpp"
58 #include "memory/oopFactory.hpp"
59 #include "runtime/jniHandles.hpp"
60 #include "runtime/mutex.hpp"
61 #include "runtime/safepoint.hpp"
62 #include "runtime/synchronizer.hpp"
63 #include "utilities/growableArray.hpp"
64 #include "utilities/ostream.hpp"
66 ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
68 ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous) :
69 _class_loader(h_class_loader()),
70 _is_anonymous(is_anonymous), _keep_alive(is_anonymous), // initially
71 _metaspace(NULL), _unloading(false), _klasses(NULL),
72 _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL),
73 _next(NULL), _dependencies(),
74 _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
75 // empty
76 }
78 void ClassLoaderData::init_dependencies(TRAPS) {
79 _dependencies.init(CHECK);
80 }
82 void ClassLoaderData::Dependencies::init(TRAPS) {
83 // Create empty dependencies array to add to. CMS requires this to be
84 // an oop so that it can track additions via card marks. We think.
85 _list_head = oopFactory::new_objectArray(2, CHECK);
86 }
88 bool ClassLoaderData::claim() {
89 if (_claimed == 1) {
90 return false;
91 }
93 return (int) Atomic::cmpxchg(1, &_claimed, 0) == 0;
94 }
96 void ClassLoaderData::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
97 if (must_claim && !claim()) {
98 return;
99 }
101 f->do_oop(&_class_loader);
102 _dependencies.oops_do(f);
103 _handles->oops_do(f);
104 if (klass_closure != NULL) {
105 classes_do(klass_closure);
106 }
107 }
109 void ClassLoaderData::Dependencies::oops_do(OopClosure* f) {
110 f->do_oop((oop*)&_list_head);
111 }
113 void ClassLoaderData::classes_do(KlassClosure* klass_closure) {
114 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
115 klass_closure->do_klass(k);
116 assert(k != k->next_link(), "no loops!");
117 }
118 }
120 void ClassLoaderData::classes_do(void f(InstanceKlass*)) {
121 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
122 if (k->oop_is_instance()) {
123 f(InstanceKlass::cast(k));
124 }
125 assert(k != k->next_link(), "no loops!");
126 }
127 }
129 void ClassLoaderData::record_dependency(Klass* k, TRAPS) {
130 ClassLoaderData * const from_cld = this;
131 ClassLoaderData * const to_cld = k->class_loader_data();
133 // Dependency to the null class loader data doesn't need to be recorded
134 // because the null class loader data never goes away.
135 if (to_cld->is_the_null_class_loader_data()) {
136 return;
137 }
139 oop to;
140 if (to_cld->is_anonymous()) {
141 // Anonymous class dependencies are through the mirror.
142 to = k->java_mirror();
143 } else {
144 to = to_cld->class_loader();
146 // If from_cld is anonymous, even if it's class_loader is a parent of 'to'
147 // we still have to add it. The class_loader won't keep from_cld alive.
148 if (!from_cld->is_anonymous()) {
149 // Check that this dependency isn't from the same or parent class_loader
150 oop from = from_cld->class_loader();
152 oop curr = from;
153 while (curr != NULL) {
154 if (curr == to) {
155 return; // this class loader is in the parent list, no need to add it.
156 }
157 curr = java_lang_ClassLoader::parent(curr);
158 }
159 }
160 }
162 // It's a dependency we won't find through GC, add it. This is relatively rare
163 // Must handle over GC point.
164 Handle dependency(THREAD, to);
165 from_cld->_dependencies.add(dependency, CHECK);
166 }
169 void ClassLoaderData::Dependencies::add(Handle dependency, TRAPS) {
170 // Check first if this dependency is already in the list.
171 // Save a pointer to the last to add to under the lock.
172 objArrayOop ok = _list_head;
173 objArrayOop last = NULL;
174 while (ok != NULL) {
175 last = ok;
176 if (ok->obj_at(0) == dependency()) {
177 // Don't need to add it
178 return;
179 }
180 ok = (objArrayOop)ok->obj_at(1);
181 }
183 // Must handle over GC points
184 assert (last != NULL, "dependencies should be initialized");
185 objArrayHandle last_handle(THREAD, last);
187 // Create a new dependency node with fields for (class_loader or mirror, next)
188 objArrayOop deps = oopFactory::new_objectArray(2, CHECK);
189 deps->obj_at_put(0, dependency());
191 // Must handle over GC points
192 objArrayHandle new_dependency(THREAD, deps);
194 // Add the dependency under lock
195 locked_add(last_handle, new_dependency, THREAD);
196 }
198 void ClassLoaderData::Dependencies::locked_add(objArrayHandle last_handle,
199 objArrayHandle new_dependency,
200 Thread* THREAD) {
202 // Have to lock and put the new dependency on the end of the dependency
203 // array so the card mark for CMS sees that this dependency is new.
204 // Can probably do this lock free with some effort.
205 ObjectLocker ol(Handle(THREAD, _list_head), THREAD);
207 oop loader_or_mirror = new_dependency->obj_at(0);
209 // Since the dependencies are only added, add to the end.
210 objArrayOop end = last_handle();
211 objArrayOop last = NULL;
212 while (end != NULL) {
213 last = end;
214 // check again if another thread added it to the end.
215 if (end->obj_at(0) == loader_or_mirror) {
216 // Don't need to add it
217 return;
218 }
219 end = (objArrayOop)end->obj_at(1);
220 }
221 assert (last != NULL, "dependencies should be initialized");
222 // fill in the first element with the oop in new_dependency.
223 if (last->obj_at(0) == NULL) {
224 last->obj_at_put(0, new_dependency->obj_at(0));
225 } else {
226 last->obj_at_put(1, new_dependency());
227 }
228 }
230 void ClassLoaderDataGraph::clear_claimed_marks() {
231 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
232 cld->clear_claimed();
233 }
234 }
236 void ClassLoaderData::add_class(Klass* k) {
237 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
238 Klass* old_value = _klasses;
239 k->set_next_link(old_value);
240 // link the new item into the list
241 _klasses = k;
243 if (TraceClassLoaderData && Verbose && k->class_loader_data() != NULL) {
244 ResourceMark rm;
245 tty->print_cr("[TraceClassLoaderData] Adding k: " PTR_FORMAT " %s to CLD: "
246 PTR_FORMAT " loader: " PTR_FORMAT " %s",
247 k,
248 k->external_name(),
249 k->class_loader_data(),
250 k->class_loader(),
251 loader_name());
252 }
253 }
255 // This is called by InstanceKlass::deallocate_contents() to remove the
256 // scratch_class for redefine classes. We need a lock because there it may not
257 // be called at a safepoint if there's an error.
258 void ClassLoaderData::remove_class(Klass* scratch_class) {
259 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
260 Klass* prev = NULL;
261 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
262 if (k == scratch_class) {
263 if (prev == NULL) {
264 _klasses = k->next_link();
265 } else {
266 Klass* next = k->next_link();
267 prev->set_next_link(next);
268 }
269 return;
270 }
271 prev = k;
272 assert(k != k->next_link(), "no loops!");
273 }
274 ShouldNotReachHere(); // should have found this class!!
275 }
277 void ClassLoaderData::unload() {
278 _unloading = true;
280 if (TraceClassLoaderData) {
281 ResourceMark rm;
282 tty->print("[ClassLoaderData: unload loader data "PTR_FORMAT, this);
283 tty->print(" for instance "PTR_FORMAT" of %s", class_loader(),
284 loader_name());
285 if (is_anonymous()) {
286 tty->print(" for anonymous class "PTR_FORMAT " ", _klasses);
287 }
288 tty->print_cr("]");
289 }
290 }
292 bool ClassLoaderData::is_alive(BoolObjectClosure* is_alive_closure) const {
293 bool alive =
294 is_anonymous() ?
295 is_alive_closure->do_object_b(_klasses->java_mirror()) :
296 class_loader() == NULL || is_alive_closure->do_object_b(class_loader());
297 assert(!alive || claimed(), "must be claimed");
298 return alive;
299 }
302 ClassLoaderData::~ClassLoaderData() {
303 Metaspace *m = _metaspace;
304 if (m != NULL) {
305 _metaspace = NULL;
306 // release the metaspace
307 delete m;
308 // release the handles
309 if (_handles != NULL) {
310 JNIHandleBlock::release_block(_handles);
311 _handles = NULL;
312 }
313 }
315 // Clear all the JNI handles for methods
316 // These aren't deallocated and are going to look like a leak, but that's
317 // needed because we can't really get rid of jmethodIDs because we don't
318 // know when native code is going to stop using them. The spec says that
319 // they're "invalid" but existing programs likely rely on their being
320 // NULL after class unloading.
321 if (_jmethod_ids != NULL) {
322 Method::clear_jmethod_ids(this);
323 }
324 // Delete lock
325 delete _metaspace_lock;
327 // Delete free list
328 if (_deallocate_list != NULL) {
329 delete _deallocate_list;
330 }
331 }
333 /**
334 * Returns true if this class loader data is for the extension class loader.
335 */
336 bool ClassLoaderData::is_ext_class_loader_data() const {
337 return SystemDictionary::is_ext_class_loader(class_loader());
338 }
340 Metaspace* ClassLoaderData::metaspace_non_null() {
341 assert(!DumpSharedSpaces, "wrong metaspace!");
342 // If the metaspace has not been allocated, create a new one. Might want
343 // to create smaller arena for Reflection class loaders also.
344 // The reason for the delayed allocation is because some class loaders are
345 // simply for delegating with no metadata of their own.
346 if (_metaspace == NULL) {
347 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
348 // Check again if metaspace has been allocated while we were getting this lock.
349 if (_metaspace != NULL) {
350 return _metaspace;
351 }
352 if (this == the_null_class_loader_data()) {
353 assert (class_loader() == NULL, "Must be");
354 set_metaspace(new Metaspace(_metaspace_lock, Metaspace::BootMetaspaceType));
355 } else if (is_anonymous()) {
356 if (TraceClassLoaderData && Verbose && class_loader() != NULL) {
357 tty->print_cr("is_anonymous: %s", class_loader()->klass()->internal_name());
358 }
359 set_metaspace(new Metaspace(_metaspace_lock, Metaspace::AnonymousMetaspaceType));
360 } else if (class_loader()->is_a(SystemDictionary::reflect_DelegatingClassLoader_klass())) {
361 if (TraceClassLoaderData && Verbose && class_loader() != NULL) {
362 tty->print_cr("is_reflection: %s", class_loader()->klass()->internal_name());
363 }
364 set_metaspace(new Metaspace(_metaspace_lock, Metaspace::ReflectionMetaspaceType));
365 } else {
366 set_metaspace(new Metaspace(_metaspace_lock, Metaspace::StandardMetaspaceType));
367 }
368 }
369 return _metaspace;
370 }
372 JNIHandleBlock* ClassLoaderData::handles() const { return _handles; }
373 void ClassLoaderData::set_handles(JNIHandleBlock* handles) { _handles = handles; }
375 jobject ClassLoaderData::add_handle(Handle h) {
376 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
377 if (handles() == NULL) {
378 set_handles(JNIHandleBlock::allocate_block());
379 }
380 return handles()->allocate_handle(h());
381 }
383 // Add this metadata pointer to be freed when it's safe. This is only during
384 // class unloading because Handles might point to this metadata field.
385 void ClassLoaderData::add_to_deallocate_list(Metadata* m) {
386 // Metadata in shared region isn't deleted.
387 if (!m->is_shared()) {
388 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
389 if (_deallocate_list == NULL) {
390 _deallocate_list = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(100, true);
391 }
392 _deallocate_list->append_if_missing(m);
393 }
394 }
396 // Deallocate free metadata on the free list. How useful the PermGen was!
397 void ClassLoaderData::free_deallocate_list() {
398 // Don't need lock, at safepoint
399 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
400 if (_deallocate_list == NULL) {
401 return;
402 }
403 // Go backwards because this removes entries that are freed.
404 for (int i = _deallocate_list->length() - 1; i >= 0; i--) {
405 Metadata* m = _deallocate_list->at(i);
406 if (!m->on_stack()) {
407 _deallocate_list->remove_at(i);
408 // There are only three types of metadata that we deallocate directly.
409 // Cast them so they can be used by the template function.
410 if (m->is_method()) {
411 MetadataFactory::free_metadata(this, (Method*)m);
412 } else if (m->is_constantPool()) {
413 MetadataFactory::free_metadata(this, (ConstantPool*)m);
414 } else if (m->is_klass()) {
415 MetadataFactory::free_metadata(this, (InstanceKlass*)m);
416 } else {
417 ShouldNotReachHere();
418 }
419 }
420 }
421 }
423 // These anonymous class loaders are to contain classes used for JSR292
424 ClassLoaderData* ClassLoaderData::anonymous_class_loader_data(oop loader, TRAPS) {
425 // Add a new class loader data to the graph.
426 return ClassLoaderDataGraph::add(NULL, loader, CHECK_NULL);
427 }
429 const char* ClassLoaderData::loader_name() {
430 // Handles null class loader
431 return SystemDictionary::loader_name(class_loader());
432 }
434 #ifndef PRODUCT
435 // Define to dump klasses
436 #undef CLD_DUMP_KLASSES
438 void ClassLoaderData::dump(outputStream * const out) {
439 ResourceMark rm;
440 out->print("ClassLoaderData CLD: "PTR_FORMAT", loader: "PTR_FORMAT", loader_klass: "PTR_FORMAT" %s {",
441 this, class_loader(),
442 class_loader() != NULL ? class_loader()->klass() : NULL, loader_name());
443 if (claimed()) out->print(" claimed ");
444 if (is_unloading()) out->print(" unloading ");
445 out->print(" handles " INTPTR_FORMAT, handles());
446 out->cr();
447 if (metaspace_or_null() != NULL) {
448 out->print_cr("metaspace: " PTR_FORMAT, metaspace_or_null());
449 metaspace_or_null()->dump(out);
450 } else {
451 out->print_cr("metaspace: NULL");
452 }
454 #ifdef CLD_DUMP_KLASSES
455 if (Verbose) {
456 ResourceMark rm;
457 Klass* k = _klasses;
458 while (k != NULL) {
459 out->print_cr("klass "PTR_FORMAT", %s, CT: %d, MUT: %d", k, k->name()->as_C_string(),
460 k->has_modified_oops(), k->has_accumulated_modified_oops());
461 assert(k != k->next_link(), "no loops!");
462 k = k->next_link();
463 }
464 }
465 #endif // CLD_DUMP_KLASSES
466 #undef CLD_DUMP_KLASSES
467 if (_jmethod_ids != NULL) {
468 Method::print_jmethod_ids(this, out);
469 }
470 out->print_cr("}");
471 }
472 #endif // PRODUCT
474 void ClassLoaderData::verify() {
475 oop cl = class_loader();
477 guarantee(this == class_loader_data(cl) || is_anonymous(), "Must be the same");
478 guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data() || is_anonymous(), "must be");
480 // Verify the integrity of the allocated space.
481 if (metaspace_or_null() != NULL) {
482 metaspace_or_null()->verify();
483 }
485 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
486 guarantee(k->class_loader_data() == this, "Must be the same");
487 k->verify();
488 assert(k != k->next_link(), "no loops!");
489 }
490 }
493 // GC root of class loader data created.
494 ClassLoaderData* ClassLoaderDataGraph::_head = NULL;
495 ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL;
496 ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL;
499 // Add a new class loader data node to the list. Assign the newly created
500 // ClassLoaderData into the java/lang/ClassLoader object as a hidden field
501 ClassLoaderData* ClassLoaderDataGraph::add(ClassLoaderData** cld_addr, Handle loader, TRAPS) {
502 // Not assigned a class loader data yet.
503 // Create one.
504 ClassLoaderData* *list_head = &_head;
505 ClassLoaderData* next = _head;
507 bool is_anonymous = (cld_addr == NULL);
508 ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous);
510 if (cld_addr != NULL) {
511 // First, Atomically set it
512 ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL);
513 if (old != NULL) {
514 delete cld;
515 // Returns the data.
516 return old;
517 }
518 }
520 // We won the race, and therefore the task of adding the data to the list of
521 // class loader data
522 do {
523 cld->set_next(next);
524 ClassLoaderData* exchanged = (ClassLoaderData*)Atomic::cmpxchg_ptr(cld, list_head, next);
525 if (exchanged == next) {
526 if (TraceClassLoaderData) {
527 ResourceMark rm;
528 tty->print("[ClassLoaderData: ");
529 tty->print("create class loader data "PTR_FORMAT, cld);
530 tty->print(" for instance "PTR_FORMAT" of %s", cld->class_loader(),
531 cld->loader_name());
532 tty->print_cr("]");
533 }
534 // Create dependencies after the CLD is added to the list. Otherwise,
535 // the GC GC will not find the CLD and the _class_loader field will
536 // not be updated.
537 cld->init_dependencies(CHECK_NULL);
538 return cld;
539 }
540 next = exchanged;
541 } while (true);
543 }
545 void ClassLoaderDataGraph::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
546 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
547 cld->oops_do(f, klass_closure, must_claim);
548 }
549 }
551 void ClassLoaderDataGraph::keep_alive_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
552 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
553 if (cld->keep_alive()) {
554 cld->oops_do(f, klass_closure, must_claim);
555 }
556 }
557 }
559 void ClassLoaderDataGraph::always_strong_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
560 if (ClassUnloading) {
561 ClassLoaderData::the_null_class_loader_data()->oops_do(f, klass_closure, must_claim);
562 // keep any special CLDs alive.
563 ClassLoaderDataGraph::keep_alive_oops_do(f, klass_closure, must_claim);
564 } else {
565 ClassLoaderDataGraph::oops_do(f, klass_closure, must_claim);
566 }
567 }
569 void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) {
570 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
571 cld->classes_do(klass_closure);
572 }
573 }
575 GrowableArray<ClassLoaderData*>* ClassLoaderDataGraph::new_clds() {
576 assert(_head == NULL || _saved_head != NULL, "remember_new_clds(true) not called?");
578 GrowableArray<ClassLoaderData*>* array = new GrowableArray<ClassLoaderData*>();
580 // The CLDs in [_head, _saved_head] were all added during last call to remember_new_clds(true);
581 ClassLoaderData* curr = _head;
582 while (curr != _saved_head) {
583 if (!curr->claimed()) {
584 array->push(curr);
586 if (TraceClassLoaderData) {
587 tty->print("[ClassLoaderData] found new CLD: ");
588 curr->print_value_on(tty);
589 tty->cr();
590 }
591 }
593 curr = curr->_next;
594 }
596 return array;
597 }
599 #ifndef PRODUCT
600 // for debugging and hsfind(x)
601 bool ClassLoaderDataGraph::contains(address x) {
602 // I think we need the _metaspace_lock taken here because the class loader
603 // data graph could be changing while we are walking it (new entries added,
604 // new entries being unloaded, etc).
605 if (DumpSharedSpaces) {
606 // There are only two metaspaces to worry about.
607 ClassLoaderData* ncld = ClassLoaderData::the_null_class_loader_data();
608 return (ncld->ro_metaspace()->contains(x) || ncld->rw_metaspace()->contains(x));
609 }
611 if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(x)) {
612 return true;
613 }
615 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
616 if (cld->metaspace_or_null() != NULL && cld->metaspace_or_null()->contains(x)) {
617 return true;
618 }
619 }
621 // Could also be on an unloading list which is okay, ie. still allocated
622 // for a little while.
623 for (ClassLoaderData* ucld = _unloading; ucld != NULL; ucld = ucld->next()) {
624 if (ucld->metaspace_or_null() != NULL && ucld->metaspace_or_null()->contains(x)) {
625 return true;
626 }
627 }
628 return false;
629 }
631 bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) {
632 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
633 if (loader_data == data) {
634 return true;
635 }
636 }
638 return false;
639 }
640 #endif // PRODUCT
643 // Move class loader data from main list to the unloaded list for unloading
644 // and deallocation later.
645 bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure) {
646 ClassLoaderData* data = _head;
647 ClassLoaderData* prev = NULL;
648 bool seen_dead_loader = false;
649 // mark metadata seen on the stack and code cache so we can delete
650 // unneeded entries.
651 bool has_redefined_a_class = JvmtiExport::has_redefined_a_class();
652 MetadataOnStackMark md_on_stack;
653 while (data != NULL) {
654 if (data->keep_alive() || data->is_alive(is_alive_closure)) {
655 if (has_redefined_a_class) {
656 data->classes_do(InstanceKlass::purge_previous_versions);
657 }
658 data->free_deallocate_list();
659 prev = data;
660 data = data->next();
661 continue;
662 }
663 seen_dead_loader = true;
664 ClassLoaderData* dead = data;
665 dead->unload();
666 data = data->next();
667 // Remove from loader list.
668 if (prev != NULL) {
669 prev->set_next(data);
670 } else {
671 assert(dead == _head, "sanity check");
672 _head = data;
673 }
674 dead->set_next(_unloading);
675 _unloading = dead;
676 }
677 return seen_dead_loader;
678 }
680 void ClassLoaderDataGraph::purge() {
681 ClassLoaderData* list = _unloading;
682 _unloading = NULL;
683 ClassLoaderData* next = list;
684 while (next != NULL) {
685 ClassLoaderData* purge_me = next;
686 next = purge_me->next();
687 delete purge_me;
688 }
689 }
691 // CDS support
693 // Global metaspaces for writing information to the shared archive. When
694 // application CDS is supported, we may need one per metaspace, so this
695 // sort of looks like it.
696 Metaspace* ClassLoaderData::_ro_metaspace = NULL;
697 Metaspace* ClassLoaderData::_rw_metaspace = NULL;
698 static bool _shared_metaspaces_initialized = false;
700 // Initialize shared metaspaces (change to call from somewhere not lazily)
701 void ClassLoaderData::initialize_shared_metaspaces() {
702 assert(DumpSharedSpaces, "only use this for dumping shared spaces");
703 assert(this == ClassLoaderData::the_null_class_loader_data(),
704 "only supported for null loader data for now");
705 assert (!_shared_metaspaces_initialized, "only initialize once");
706 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
707 _ro_metaspace = new Metaspace(_metaspace_lock, Metaspace::ROMetaspaceType);
708 _rw_metaspace = new Metaspace(_metaspace_lock, Metaspace::ReadWriteMetaspaceType);
709 _shared_metaspaces_initialized = true;
710 }
712 Metaspace* ClassLoaderData::ro_metaspace() {
713 assert(_ro_metaspace != NULL, "should already be initialized");
714 return _ro_metaspace;
715 }
717 Metaspace* ClassLoaderData::rw_metaspace() {
718 assert(_rw_metaspace != NULL, "should already be initialized");
719 return _rw_metaspace;
720 }
723 ClassLoaderDataGraphMetaspaceIterator::ClassLoaderDataGraphMetaspaceIterator() {
724 _data = ClassLoaderDataGraph::_head;
725 }
727 ClassLoaderDataGraphMetaspaceIterator::~ClassLoaderDataGraphMetaspaceIterator() {}
729 #ifndef PRODUCT
730 // callable from debugger
731 extern "C" int print_loader_data_graph() {
732 ClassLoaderDataGraph::dump_on(tty);
733 return 0;
734 }
736 void ClassLoaderDataGraph::verify() {
737 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
738 data->verify();
739 }
740 }
742 void ClassLoaderDataGraph::dump_on(outputStream * const out) {
743 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
744 data->dump(out);
745 }
746 MetaspaceAux::dump(out);
747 }
748 #endif // PRODUCT
750 void ClassLoaderData::print_value_on(outputStream* out) const {
751 if (class_loader() == NULL) {
752 out->print("NULL class_loader");
753 } else {
754 out->print("class loader "PTR_FORMAT, this);
755 class_loader()->print_value_on(out);
756 }
757 }