Tue, 14 May 2013 11:34:30 +0400
8014448: Purge PrintCompactFieldsSavings
Summary: Remove obsolete debugging code.
Reviewed-by: dholmes, kvn
Contributed-by: Aleksey Shipilev <aleksey.shipilev@oracle.com>
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/gcLocker.hpp"
57 #include "memory/metadataFactory.hpp"
58 #include "memory/metaspaceShared.hpp"
59 #include "memory/oopFactory.hpp"
60 #include "runtime/jniHandles.hpp"
61 #include "runtime/mutex.hpp"
62 #include "runtime/safepoint.hpp"
63 #include "runtime/synchronizer.hpp"
64 #include "utilities/growableArray.hpp"
65 #include "utilities/ostream.hpp"
67 ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
69 ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous, Dependencies dependencies) :
70 _class_loader(h_class_loader()),
71 _is_anonymous(is_anonymous), _keep_alive(is_anonymous), // initially
72 _metaspace(NULL), _unloading(false), _klasses(NULL),
73 _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL),
74 _next(NULL), _dependencies(dependencies),
75 _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
76 // empty
77 }
79 void ClassLoaderData::init_dependencies(TRAPS) {
80 assert(!Universe::is_fully_initialized(), "should only be called when initializing");
81 assert(is_the_null_class_loader_data(), "should only call this for the null class loader");
82 _dependencies.init(CHECK);
83 }
85 void ClassLoaderData::Dependencies::init(TRAPS) {
86 // Create empty dependencies array to add to. CMS requires this to be
87 // an oop so that it can track additions via card marks. We think.
88 _list_head = oopFactory::new_objectArray(2, CHECK);
89 }
91 bool ClassLoaderData::claim() {
92 if (_claimed == 1) {
93 return false;
94 }
96 return (int) Atomic::cmpxchg(1, &_claimed, 0) == 0;
97 }
99 void ClassLoaderData::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
100 if (must_claim && !claim()) {
101 return;
102 }
104 f->do_oop(&_class_loader);
105 _dependencies.oops_do(f);
106 _handles->oops_do(f);
107 if (klass_closure != NULL) {
108 classes_do(klass_closure);
109 }
110 }
112 void ClassLoaderData::Dependencies::oops_do(OopClosure* f) {
113 f->do_oop((oop*)&_list_head);
114 }
116 void ClassLoaderData::classes_do(KlassClosure* klass_closure) {
117 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
118 klass_closure->do_klass(k);
119 assert(k != k->next_link(), "no loops!");
120 }
121 }
123 void ClassLoaderData::classes_do(void f(InstanceKlass*)) {
124 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
125 if (k->oop_is_instance()) {
126 f(InstanceKlass::cast(k));
127 }
128 assert(k != k->next_link(), "no loops!");
129 }
130 }
132 void ClassLoaderData::record_dependency(Klass* k, TRAPS) {
133 ClassLoaderData * const from_cld = this;
134 ClassLoaderData * const to_cld = k->class_loader_data();
136 // Dependency to the null class loader data doesn't need to be recorded
137 // because the null class loader data never goes away.
138 if (to_cld->is_the_null_class_loader_data()) {
139 return;
140 }
142 oop to;
143 if (to_cld->is_anonymous()) {
144 // Anonymous class dependencies are through the mirror.
145 to = k->java_mirror();
146 } else {
147 to = to_cld->class_loader();
149 // If from_cld is anonymous, even if it's class_loader is a parent of 'to'
150 // we still have to add it. The class_loader won't keep from_cld alive.
151 if (!from_cld->is_anonymous()) {
152 // Check that this dependency isn't from the same or parent class_loader
153 oop from = from_cld->class_loader();
155 oop curr = from;
156 while (curr != NULL) {
157 if (curr == to) {
158 return; // this class loader is in the parent list, no need to add it.
159 }
160 curr = java_lang_ClassLoader::parent(curr);
161 }
162 }
163 }
165 // It's a dependency we won't find through GC, add it. This is relatively rare
166 // Must handle over GC point.
167 Handle dependency(THREAD, to);
168 from_cld->_dependencies.add(dependency, CHECK);
169 }
172 void ClassLoaderData::Dependencies::add(Handle dependency, TRAPS) {
173 // Check first if this dependency is already in the list.
174 // Save a pointer to the last to add to under the lock.
175 objArrayOop ok = _list_head;
176 objArrayOop last = NULL;
177 while (ok != NULL) {
178 last = ok;
179 if (ok->obj_at(0) == dependency()) {
180 // Don't need to add it
181 return;
182 }
183 ok = (objArrayOop)ok->obj_at(1);
184 }
186 // Must handle over GC points
187 assert (last != NULL, "dependencies should be initialized");
188 objArrayHandle last_handle(THREAD, last);
190 // Create a new dependency node with fields for (class_loader or mirror, next)
191 objArrayOop deps = oopFactory::new_objectArray(2, CHECK);
192 deps->obj_at_put(0, dependency());
194 // Must handle over GC points
195 objArrayHandle new_dependency(THREAD, deps);
197 // Add the dependency under lock
198 locked_add(last_handle, new_dependency, THREAD);
199 }
201 void ClassLoaderData::Dependencies::locked_add(objArrayHandle last_handle,
202 objArrayHandle new_dependency,
203 Thread* THREAD) {
205 // Have to lock and put the new dependency on the end of the dependency
206 // array so the card mark for CMS sees that this dependency is new.
207 // Can probably do this lock free with some effort.
208 ObjectLocker ol(Handle(THREAD, _list_head), THREAD);
210 oop loader_or_mirror = new_dependency->obj_at(0);
212 // Since the dependencies are only added, add to the end.
213 objArrayOop end = last_handle();
214 objArrayOop last = NULL;
215 while (end != NULL) {
216 last = end;
217 // check again if another thread added it to the end.
218 if (end->obj_at(0) == loader_or_mirror) {
219 // Don't need to add it
220 return;
221 }
222 end = (objArrayOop)end->obj_at(1);
223 }
224 assert (last != NULL, "dependencies should be initialized");
225 // fill in the first element with the oop in new_dependency.
226 if (last->obj_at(0) == NULL) {
227 last->obj_at_put(0, new_dependency->obj_at(0));
228 } else {
229 last->obj_at_put(1, new_dependency());
230 }
231 }
233 void ClassLoaderDataGraph::clear_claimed_marks() {
234 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
235 cld->clear_claimed();
236 }
237 }
239 void ClassLoaderData::add_class(Klass* k) {
240 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
241 Klass* old_value = _klasses;
242 k->set_next_link(old_value);
243 // link the new item into the list
244 _klasses = k;
246 if (TraceClassLoaderData && Verbose && k->class_loader_data() != NULL) {
247 ResourceMark rm;
248 tty->print_cr("[TraceClassLoaderData] Adding k: " PTR_FORMAT " %s to CLD: "
249 PTR_FORMAT " loader: " PTR_FORMAT " %s",
250 k,
251 k->external_name(),
252 k->class_loader_data(),
253 k->class_loader(),
254 loader_name());
255 }
256 }
258 // This is called by InstanceKlass::deallocate_contents() to remove the
259 // scratch_class for redefine classes. We need a lock because there it may not
260 // be called at a safepoint if there's an error.
261 void ClassLoaderData::remove_class(Klass* scratch_class) {
262 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
263 Klass* prev = NULL;
264 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
265 if (k == scratch_class) {
266 if (prev == NULL) {
267 _klasses = k->next_link();
268 } else {
269 Klass* next = k->next_link();
270 prev->set_next_link(next);
271 }
272 return;
273 }
274 prev = k;
275 assert(k != k->next_link(), "no loops!");
276 }
277 ShouldNotReachHere(); // should have found this class!!
278 }
280 void ClassLoaderData::unload() {
281 _unloading = true;
283 // Tell serviceability tools these classes are unloading
284 classes_do(InstanceKlass::notify_unload_class);
286 if (TraceClassLoaderData) {
287 ResourceMark rm;
288 tty->print("[ClassLoaderData: unload loader data "PTR_FORMAT, this);
289 tty->print(" for instance "PTR_FORMAT" of %s", class_loader(),
290 loader_name());
291 if (is_anonymous()) {
292 tty->print(" for anonymous class "PTR_FORMAT " ", _klasses);
293 }
294 tty->print_cr("]");
295 }
296 }
298 bool ClassLoaderData::is_alive(BoolObjectClosure* is_alive_closure) const {
299 bool alive =
300 is_anonymous() ?
301 is_alive_closure->do_object_b(_klasses->java_mirror()) :
302 class_loader() == NULL || is_alive_closure->do_object_b(class_loader());
303 assert(!alive || claimed(), "must be claimed");
304 return alive;
305 }
308 ClassLoaderData::~ClassLoaderData() {
309 // Release C heap structures for all the classes.
310 classes_do(InstanceKlass::release_C_heap_structures);
312 Metaspace *m = _metaspace;
313 if (m != NULL) {
314 _metaspace = NULL;
315 // release the metaspace
316 delete m;
317 // release the handles
318 if (_handles != NULL) {
319 JNIHandleBlock::release_block(_handles);
320 _handles = NULL;
321 }
322 }
324 // Clear all the JNI handles for methods
325 // These aren't deallocated and are going to look like a leak, but that's
326 // needed because we can't really get rid of jmethodIDs because we don't
327 // know when native code is going to stop using them. The spec says that
328 // they're "invalid" but existing programs likely rely on their being
329 // NULL after class unloading.
330 if (_jmethod_ids != NULL) {
331 Method::clear_jmethod_ids(this);
332 }
333 // Delete lock
334 delete _metaspace_lock;
336 // Delete free list
337 if (_deallocate_list != NULL) {
338 delete _deallocate_list;
339 }
340 }
342 /**
343 * Returns true if this class loader data is for the extension class loader.
344 */
345 bool ClassLoaderData::is_ext_class_loader_data() const {
346 return SystemDictionary::is_ext_class_loader(class_loader());
347 }
349 Metaspace* ClassLoaderData::metaspace_non_null() {
350 assert(!DumpSharedSpaces, "wrong metaspace!");
351 // If the metaspace has not been allocated, create a new one. Might want
352 // to create smaller arena for Reflection class loaders also.
353 // The reason for the delayed allocation is because some class loaders are
354 // simply for delegating with no metadata of their own.
355 if (_metaspace == NULL) {
356 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
357 // Check again if metaspace has been allocated while we were getting this lock.
358 if (_metaspace != NULL) {
359 return _metaspace;
360 }
361 if (this == the_null_class_loader_data()) {
362 assert (class_loader() == NULL, "Must be");
363 set_metaspace(new Metaspace(_metaspace_lock, Metaspace::BootMetaspaceType));
364 } else if (is_anonymous()) {
365 if (TraceClassLoaderData && Verbose && class_loader() != NULL) {
366 tty->print_cr("is_anonymous: %s", class_loader()->klass()->internal_name());
367 }
368 set_metaspace(new Metaspace(_metaspace_lock, Metaspace::AnonymousMetaspaceType));
369 } else if (class_loader()->is_a(SystemDictionary::reflect_DelegatingClassLoader_klass())) {
370 if (TraceClassLoaderData && Verbose && class_loader() != NULL) {
371 tty->print_cr("is_reflection: %s", class_loader()->klass()->internal_name());
372 }
373 set_metaspace(new Metaspace(_metaspace_lock, Metaspace::ReflectionMetaspaceType));
374 } else {
375 set_metaspace(new Metaspace(_metaspace_lock, Metaspace::StandardMetaspaceType));
376 }
377 }
378 return _metaspace;
379 }
381 JNIHandleBlock* ClassLoaderData::handles() const { return _handles; }
382 void ClassLoaderData::set_handles(JNIHandleBlock* handles) { _handles = handles; }
384 jobject ClassLoaderData::add_handle(Handle h) {
385 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
386 if (handles() == NULL) {
387 set_handles(JNIHandleBlock::allocate_block());
388 }
389 return handles()->allocate_handle(h());
390 }
392 // Add this metadata pointer to be freed when it's safe. This is only during
393 // class unloading because Handles might point to this metadata field.
394 void ClassLoaderData::add_to_deallocate_list(Metadata* m) {
395 // Metadata in shared region isn't deleted.
396 if (!m->is_shared()) {
397 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
398 if (_deallocate_list == NULL) {
399 _deallocate_list = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(100, true);
400 }
401 _deallocate_list->append_if_missing(m);
402 }
403 }
405 // Deallocate free metadata on the free list. How useful the PermGen was!
406 void ClassLoaderData::free_deallocate_list() {
407 // Don't need lock, at safepoint
408 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
409 if (_deallocate_list == NULL) {
410 return;
411 }
412 // Go backwards because this removes entries that are freed.
413 for (int i = _deallocate_list->length() - 1; i >= 0; i--) {
414 Metadata* m = _deallocate_list->at(i);
415 if (!m->on_stack()) {
416 _deallocate_list->remove_at(i);
417 // There are only three types of metadata that we deallocate directly.
418 // Cast them so they can be used by the template function.
419 if (m->is_method()) {
420 MetadataFactory::free_metadata(this, (Method*)m);
421 } else if (m->is_constantPool()) {
422 MetadataFactory::free_metadata(this, (ConstantPool*)m);
423 } else if (m->is_klass()) {
424 MetadataFactory::free_metadata(this, (InstanceKlass*)m);
425 } else {
426 ShouldNotReachHere();
427 }
428 }
429 }
430 }
432 // These anonymous class loaders are to contain classes used for JSR292
433 ClassLoaderData* ClassLoaderData::anonymous_class_loader_data(oop loader, TRAPS) {
434 // Add a new class loader data to the graph.
435 return ClassLoaderDataGraph::add(loader, true, CHECK_NULL);
436 }
438 const char* ClassLoaderData::loader_name() {
439 // Handles null class loader
440 return SystemDictionary::loader_name(class_loader());
441 }
443 #ifndef PRODUCT
444 // Define to dump klasses
445 #undef CLD_DUMP_KLASSES
447 void ClassLoaderData::dump(outputStream * const out) {
448 ResourceMark rm;
449 out->print("ClassLoaderData CLD: "PTR_FORMAT", loader: "PTR_FORMAT", loader_klass: "PTR_FORMAT" %s {",
450 this, class_loader(),
451 class_loader() != NULL ? class_loader()->klass() : NULL, loader_name());
452 if (claimed()) out->print(" claimed ");
453 if (is_unloading()) out->print(" unloading ");
454 out->print(" handles " INTPTR_FORMAT, handles());
455 out->cr();
456 if (metaspace_or_null() != NULL) {
457 out->print_cr("metaspace: " PTR_FORMAT, metaspace_or_null());
458 metaspace_or_null()->dump(out);
459 } else {
460 out->print_cr("metaspace: NULL");
461 }
463 #ifdef CLD_DUMP_KLASSES
464 if (Verbose) {
465 ResourceMark rm;
466 Klass* k = _klasses;
467 while (k != NULL) {
468 out->print_cr("klass "PTR_FORMAT", %s, CT: %d, MUT: %d", k, k->name()->as_C_string(),
469 k->has_modified_oops(), k->has_accumulated_modified_oops());
470 assert(k != k->next_link(), "no loops!");
471 k = k->next_link();
472 }
473 }
474 #endif // CLD_DUMP_KLASSES
475 #undef CLD_DUMP_KLASSES
476 if (_jmethod_ids != NULL) {
477 Method::print_jmethod_ids(this, out);
478 }
479 out->print_cr("}");
480 }
481 #endif // PRODUCT
483 void ClassLoaderData::verify() {
484 oop cl = class_loader();
486 guarantee(this == class_loader_data(cl) || is_anonymous(), "Must be the same");
487 guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data() || is_anonymous(), "must be");
489 // Verify the integrity of the allocated space.
490 if (metaspace_or_null() != NULL) {
491 metaspace_or_null()->verify();
492 }
494 for (Klass* k = _klasses; k != NULL; k = k->next_link()) {
495 guarantee(k->class_loader_data() == this, "Must be the same");
496 k->verify();
497 assert(k != k->next_link(), "no loops!");
498 }
499 }
502 // GC root of class loader data created.
503 ClassLoaderData* ClassLoaderDataGraph::_head = NULL;
504 ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL;
505 ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL;
507 // Add a new class loader data node to the list. Assign the newly created
508 // ClassLoaderData into the java/lang/ClassLoader object as a hidden field
509 ClassLoaderData* ClassLoaderDataGraph::add(Handle loader, bool is_anonymous, TRAPS) {
510 // We need to allocate all the oops for the ClassLoaderData before allocating the
511 // actual ClassLoaderData object.
512 ClassLoaderData::Dependencies dependencies(CHECK_NULL);
514 No_Safepoint_Verifier no_safepoints; // we mustn't GC until we've installed the
515 // ClassLoaderData in the graph since the CLD
516 // contains unhandled oops
518 ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous, dependencies);
521 if (!is_anonymous) {
522 ClassLoaderData** cld_addr = java_lang_ClassLoader::loader_data_addr(loader());
523 // First, Atomically set it
524 ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL);
525 if (old != NULL) {
526 delete cld;
527 // Returns the data.
528 return old;
529 }
530 }
532 // We won the race, and therefore the task of adding the data to the list of
533 // class loader data
534 ClassLoaderData** list_head = &_head;
535 ClassLoaderData* next = _head;
537 do {
538 cld->set_next(next);
539 ClassLoaderData* exchanged = (ClassLoaderData*)Atomic::cmpxchg_ptr(cld, list_head, next);
540 if (exchanged == next) {
541 if (TraceClassLoaderData) {
542 ResourceMark rm;
543 tty->print("[ClassLoaderData: ");
544 tty->print("create class loader data "PTR_FORMAT, cld);
545 tty->print(" for instance "PTR_FORMAT" of %s", cld->class_loader(),
546 cld->loader_name());
547 tty->print_cr("]");
548 }
549 return cld;
550 }
551 next = exchanged;
552 } while (true);
554 }
556 void ClassLoaderDataGraph::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
557 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
558 cld->oops_do(f, klass_closure, must_claim);
559 }
560 }
562 void ClassLoaderDataGraph::keep_alive_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
563 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
564 if (cld->keep_alive()) {
565 cld->oops_do(f, klass_closure, must_claim);
566 }
567 }
568 }
570 void ClassLoaderDataGraph::always_strong_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) {
571 if (ClassUnloading) {
572 ClassLoaderData::the_null_class_loader_data()->oops_do(f, klass_closure, must_claim);
573 // keep any special CLDs alive.
574 ClassLoaderDataGraph::keep_alive_oops_do(f, klass_closure, must_claim);
575 } else {
576 ClassLoaderDataGraph::oops_do(f, klass_closure, must_claim);
577 }
578 }
580 void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) {
581 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
582 cld->classes_do(klass_closure);
583 }
584 }
586 GrowableArray<ClassLoaderData*>* ClassLoaderDataGraph::new_clds() {
587 assert(_head == NULL || _saved_head != NULL, "remember_new_clds(true) not called?");
589 GrowableArray<ClassLoaderData*>* array = new GrowableArray<ClassLoaderData*>();
591 // The CLDs in [_head, _saved_head] were all added during last call to remember_new_clds(true);
592 ClassLoaderData* curr = _head;
593 while (curr != _saved_head) {
594 if (!curr->claimed()) {
595 array->push(curr);
597 if (TraceClassLoaderData) {
598 tty->print("[ClassLoaderData] found new CLD: ");
599 curr->print_value_on(tty);
600 tty->cr();
601 }
602 }
604 curr = curr->_next;
605 }
607 return array;
608 }
610 #ifndef PRODUCT
611 // for debugging and hsfind(x)
612 bool ClassLoaderDataGraph::contains(address x) {
613 // I think we need the _metaspace_lock taken here because the class loader
614 // data graph could be changing while we are walking it (new entries added,
615 // new entries being unloaded, etc).
616 if (DumpSharedSpaces) {
617 // There are only two metaspaces to worry about.
618 ClassLoaderData* ncld = ClassLoaderData::the_null_class_loader_data();
619 return (ncld->ro_metaspace()->contains(x) || ncld->rw_metaspace()->contains(x));
620 }
622 if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(x)) {
623 return true;
624 }
626 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
627 if (cld->metaspace_or_null() != NULL && cld->metaspace_or_null()->contains(x)) {
628 return true;
629 }
630 }
632 // Could also be on an unloading list which is okay, ie. still allocated
633 // for a little while.
634 for (ClassLoaderData* ucld = _unloading; ucld != NULL; ucld = ucld->next()) {
635 if (ucld->metaspace_or_null() != NULL && ucld->metaspace_or_null()->contains(x)) {
636 return true;
637 }
638 }
639 return false;
640 }
642 bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) {
643 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
644 if (loader_data == data) {
645 return true;
646 }
647 }
649 return false;
650 }
651 #endif // PRODUCT
654 // Move class loader data from main list to the unloaded list for unloading
655 // and deallocation later.
656 bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure) {
657 ClassLoaderData* data = _head;
658 ClassLoaderData* prev = NULL;
659 bool seen_dead_loader = false;
660 // mark metadata seen on the stack and code cache so we can delete
661 // unneeded entries.
662 bool has_redefined_a_class = JvmtiExport::has_redefined_a_class();
663 MetadataOnStackMark md_on_stack;
664 while (data != NULL) {
665 if (data->keep_alive() || data->is_alive(is_alive_closure)) {
666 if (has_redefined_a_class) {
667 data->classes_do(InstanceKlass::purge_previous_versions);
668 }
669 data->free_deallocate_list();
670 prev = data;
671 data = data->next();
672 continue;
673 }
674 seen_dead_loader = true;
675 ClassLoaderData* dead = data;
676 dead->unload();
677 data = data->next();
678 // Remove from loader list.
679 // This class loader data will no longer be found
680 // in the ClassLoaderDataGraph.
681 if (prev != NULL) {
682 prev->set_next(data);
683 } else {
684 assert(dead == _head, "sanity check");
685 _head = data;
686 }
687 dead->set_next(_unloading);
688 _unloading = dead;
689 }
690 return seen_dead_loader;
691 }
693 void ClassLoaderDataGraph::purge() {
694 ClassLoaderData* list = _unloading;
695 _unloading = NULL;
696 ClassLoaderData* next = list;
697 while (next != NULL) {
698 ClassLoaderData* purge_me = next;
699 next = purge_me->next();
700 delete purge_me;
701 }
702 Metaspace::purge();
703 }
705 // CDS support
707 // Global metaspaces for writing information to the shared archive. When
708 // application CDS is supported, we may need one per metaspace, so this
709 // sort of looks like it.
710 Metaspace* ClassLoaderData::_ro_metaspace = NULL;
711 Metaspace* ClassLoaderData::_rw_metaspace = NULL;
712 static bool _shared_metaspaces_initialized = false;
714 // Initialize shared metaspaces (change to call from somewhere not lazily)
715 void ClassLoaderData::initialize_shared_metaspaces() {
716 assert(DumpSharedSpaces, "only use this for dumping shared spaces");
717 assert(this == ClassLoaderData::the_null_class_loader_data(),
718 "only supported for null loader data for now");
719 assert (!_shared_metaspaces_initialized, "only initialize once");
720 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag);
721 _ro_metaspace = new Metaspace(_metaspace_lock, Metaspace::ROMetaspaceType);
722 _rw_metaspace = new Metaspace(_metaspace_lock, Metaspace::ReadWriteMetaspaceType);
723 _shared_metaspaces_initialized = true;
724 }
726 Metaspace* ClassLoaderData::ro_metaspace() {
727 assert(_ro_metaspace != NULL, "should already be initialized");
728 return _ro_metaspace;
729 }
731 Metaspace* ClassLoaderData::rw_metaspace() {
732 assert(_rw_metaspace != NULL, "should already be initialized");
733 return _rw_metaspace;
734 }
737 ClassLoaderDataGraphMetaspaceIterator::ClassLoaderDataGraphMetaspaceIterator() {
738 _data = ClassLoaderDataGraph::_head;
739 }
741 ClassLoaderDataGraphMetaspaceIterator::~ClassLoaderDataGraphMetaspaceIterator() {}
743 #ifndef PRODUCT
744 // callable from debugger
745 extern "C" int print_loader_data_graph() {
746 ClassLoaderDataGraph::dump_on(tty);
747 return 0;
748 }
750 void ClassLoaderDataGraph::verify() {
751 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
752 data->verify();
753 }
754 }
756 void ClassLoaderDataGraph::dump_on(outputStream * const out) {
757 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
758 data->dump(out);
759 }
760 MetaspaceAux::dump(out);
761 }
762 #endif // PRODUCT
764 void ClassLoaderData::print_value_on(outputStream* out) const {
765 if (class_loader() == NULL) {
766 out->print("NULL class_loader");
767 } else {
768 out->print("class loader "PTR_FORMAT, this);
769 class_loader()->print_value_on(out);
770 }
771 }