Mercurial > hg > truffle
comparison src/share/vm/classfile/classLoaderData.cpp @ 6725:da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>
author | coleenp |
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date | Sat, 01 Sep 2012 13:25:18 -0400 |
parents | |
children | 90273fc0a981 |
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6724:36d1d483d5d6 | 6725:da91efe96a93 |
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1 /* | |
2 * Copyright (c) 2012, 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 */ | |
24 | |
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(). | |
48 | |
49 #include "precompiled.hpp" | |
50 #include "classfile/classLoaderData.hpp" | |
51 #include "classfile/classLoaderData.inline.hpp" | |
52 #include "classfile/javaClasses.hpp" | |
53 #include "classfile/systemDictionary.hpp" | |
54 #include "code/codeCache.hpp" | |
55 #include "memory/metadataFactory.hpp" | |
56 #include "memory/metaspaceShared.hpp" | |
57 #include "prims/jvmtiRedefineClasses.hpp" | |
58 #include "runtime/jniHandles.hpp" | |
59 #include "runtime/mutex.hpp" | |
60 #include "runtime/safepoint.hpp" | |
61 #include "runtime/synchronizer.hpp" | |
62 #include "utilities/growableArray.hpp" | |
63 #include "utilities/ostream.hpp" | |
64 | |
65 ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL; | |
66 | |
67 ClassLoaderData::ClassLoaderData(Handle h_class_loader) : _class_loader(h_class_loader()), | |
68 _metaspace(NULL), _unloading(false), _klasses(NULL), | |
69 _claimed(0), _jmethod_ids(NULL), _handles(NULL), | |
70 _deallocate_list(NULL), _next(NULL), | |
71 _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) { | |
72 // empty | |
73 } | |
74 | |
75 bool ClassLoaderData::claim() { | |
76 if (_claimed == 1) { | |
77 return false; | |
78 } | |
79 | |
80 return (int) Atomic::cmpxchg(1, &_claimed, 0) == 0; | |
81 } | |
82 | |
83 void ClassLoaderData::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { | |
84 if (must_claim && !claim()) { | |
85 return; | |
86 } | |
87 | |
88 f->do_oop(&_class_loader); | |
89 _handles->oops_do(f); | |
90 if (klass_closure != NULL) { | |
91 classes_do(klass_closure); | |
92 } | |
93 } | |
94 | |
95 void ClassLoaderData::classes_do(KlassClosure* klass_closure) { | |
96 for (Klass* k = _klasses; k != NULL; k = k->next_link()) { | |
97 klass_closure->do_klass(k); | |
98 } | |
99 } | |
100 | |
101 void ClassLoaderData::classes_do(void f(InstanceKlass*)) { | |
102 for (Klass* k = _klasses; k != NULL; k = k->next_link()) { | |
103 if (k->oop_is_instance()) { | |
104 f(InstanceKlass::cast(k)); | |
105 } | |
106 } | |
107 } | |
108 | |
109 void ClassLoaderData::record_dependency(Klass* k, TRAPS) { | |
110 ClassLoaderData * const from_cld = this; | |
111 ClassLoaderData * const to_cld = k->class_loader_data(); | |
112 | |
113 // Records dependency between non-null class loaders only. | |
114 if (to_cld->is_the_null_class_loader_data() || from_cld->is_the_null_class_loader_data()) { | |
115 return; | |
116 } | |
117 | |
118 // Check that this dependency isn't from the same or parent class_loader | |
119 oop to = to_cld->class_loader(); | |
120 oop from = from_cld->class_loader(); | |
121 | |
122 oop curr = from; | |
123 while (curr != NULL) { | |
124 if (curr == to) { | |
125 return; // this class loader is in the parent list, no need to add it. | |
126 } | |
127 curr = java_lang_ClassLoader::parent(curr); | |
128 } | |
129 | |
130 // It's a dependency we won't find through GC, add it. This is relatively rare | |
131 from_cld->add_dependency(to_cld, CHECK); | |
132 } | |
133 | |
134 bool ClassLoaderData::has_dependency(ClassLoaderData* dependency) { | |
135 oop loader = dependency->class_loader(); | |
136 | |
137 // Get objArrayOop out of the class_loader oop and see if this dependency | |
138 // is there. Don't safepoint! These are all oops. | |
139 // Dependency list is (oop class_loader, objArrayOop next) | |
140 objArrayOop ok = (objArrayOop)java_lang_ClassLoader::dependencies(class_loader()); | |
141 while (ok != NULL) { | |
142 if (ok->obj_at(0) == loader) { | |
143 return true; | |
144 } | |
145 ok = (objArrayOop)ok->obj_at(1); | |
146 } | |
147 return false; | |
148 } | |
149 | |
150 void ClassLoaderData::add_dependency(ClassLoaderData* dependency, TRAPS) { | |
151 // Minimize the number of duplicates in the list. | |
152 if (has_dependency(dependency)) { | |
153 return; | |
154 } | |
155 | |
156 // Create a new dependency node with fields for (class_loader, next) | |
157 objArrayOop deps = oopFactory::new_objectArray(2, CHECK); | |
158 deps->obj_at_put(0, dependency->class_loader()); | |
159 | |
160 // Add this lock free, using compare and exchange, need barriers for GC | |
161 // Do the barrier first. | |
162 HeapWord* addr = java_lang_ClassLoader::dependencies_addr(class_loader()); | |
163 while (true) { | |
164 oop old_dependency = java_lang_ClassLoader::dependencies(class_loader()); | |
165 deps->obj_at_put(1, old_dependency); | |
166 | |
167 oop newold = oopDesc::atomic_compare_exchange_oop((oop)deps, addr, old_dependency, true); | |
168 if (newold == old_dependency) { | |
169 update_barrier_set((void*)addr, (oop)deps); | |
170 // we won the race to add this dependency | |
171 break; | |
172 } | |
173 } | |
174 } | |
175 | |
176 | |
177 void ClassLoaderDataGraph::clear_claimed_marks() { | |
178 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { | |
179 cld->clear_claimed(); | |
180 } | |
181 } | |
182 | |
183 void ClassLoaderData::add_class(Klass* k) { | |
184 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); | |
185 Klass* old_value = _klasses; | |
186 k->set_next_link(old_value); | |
187 // link the new item into the list | |
188 _klasses = k; | |
189 | |
190 if (TraceClassLoaderData && k->class_loader_data() != NULL) { | |
191 ResourceMark rm; | |
192 tty->print_cr("[TraceClassLoaderData] Adding k: " PTR_FORMAT " %s to CLD: " | |
193 PTR_FORMAT " loader: " PTR_FORMAT " %s", | |
194 k, | |
195 k->external_name(), | |
196 k->class_loader_data(), | |
197 k->class_loader(), | |
198 k->class_loader() != NULL ? k->class_loader()->klass()->external_name() : "NULL" | |
199 ); | |
200 } | |
201 } | |
202 | |
203 // This is called by InstanceKlass::deallocate_contents() to remove the | |
204 // scratch_class for redefine classes. We need a lock because there it may not | |
205 // be called at a safepoint if there's an error. | |
206 void ClassLoaderData::remove_class(Klass* scratch_class) { | |
207 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); | |
208 Klass* prev = NULL; | |
209 for (Klass* k = _klasses; k != NULL; k = k->next_link()) { | |
210 if (k == scratch_class) { | |
211 if (prev == NULL) { | |
212 _klasses = k->next_link(); | |
213 } else { | |
214 Klass* next = k->next_link(); | |
215 prev->set_next_link(next); | |
216 } | |
217 return; | |
218 } | |
219 prev = k; | |
220 } | |
221 ShouldNotReachHere(); // should have found this class!! | |
222 } | |
223 | |
224 ClassLoaderData::~ClassLoaderData() { | |
225 Metaspace *m = _metaspace; | |
226 if (m != NULL) { | |
227 _metaspace = NULL; | |
228 // release the metaspace | |
229 delete m; | |
230 // release the handles | |
231 if (_handles != NULL) { | |
232 JNIHandleBlock::release_block(_handles); | |
233 _handles = NULL; | |
234 } | |
235 } | |
236 | |
237 // Clear all the JNI handles for methods | |
238 // These aren't deallocated and are going to look like a leak, but that's | |
239 // needed because we can't really get rid of jmethodIDs because we don't | |
240 // know when native code is going to stop using them. The spec says that | |
241 // they're "invalid" but existing programs likely rely on their being | |
242 // NULL after class unloading. | |
243 if (_jmethod_ids != NULL) { | |
244 Method::clear_jmethod_ids(this); | |
245 } | |
246 // Delete lock | |
247 delete _metaspace_lock; | |
248 | |
249 // Delete free list | |
250 if (_deallocate_list != NULL) { | |
251 delete _deallocate_list; | |
252 } | |
253 } | |
254 | |
255 Metaspace* ClassLoaderData::metaspace_non_null() { | |
256 // If the metaspace has not been allocated, create a new one. Might want | |
257 // to create smaller arena for Reflection class loaders also. | |
258 // The reason for the delayed allocation is because some class loaders are | |
259 // simply for delegating with no metadata of their own. | |
260 if (_metaspace == NULL) { | |
261 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); | |
262 // Check again if metaspace has been allocated while we were getting this lock. | |
263 if (_metaspace != NULL) { | |
264 return _metaspace; | |
265 } | |
266 if (class_loader() == NULL) { | |
267 assert(this == the_null_class_loader_data(), "Must be"); | |
268 size_t word_size = Metaspace::first_chunk_word_size(); | |
269 set_metaspace(new Metaspace(_metaspace_lock, word_size)); | |
270 } else { | |
271 set_metaspace(new Metaspace(_metaspace_lock)); // default size for now. | |
272 } | |
273 } | |
274 return _metaspace; | |
275 } | |
276 | |
277 JNIHandleBlock* ClassLoaderData::handles() const { return _handles; } | |
278 void ClassLoaderData::set_handles(JNIHandleBlock* handles) { _handles = handles; } | |
279 | |
280 jobject ClassLoaderData::add_handle(Handle h) { | |
281 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); | |
282 if (handles() == NULL) { | |
283 set_handles(JNIHandleBlock::allocate_block()); | |
284 } | |
285 return handles()->allocate_handle(h()); | |
286 } | |
287 | |
288 // Add this metadata pointer to be freed when it's safe. This is only during | |
289 // class unloading because Handles might point to this metadata field. | |
290 void ClassLoaderData::add_to_deallocate_list(Metadata* m) { | |
291 // Metadata in shared region isn't deleted. | |
292 if (!m->is_shared()) { | |
293 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); | |
294 if (_deallocate_list == NULL) { | |
295 _deallocate_list = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(100, true); | |
296 } | |
297 _deallocate_list->append_if_missing(m); | |
298 } | |
299 } | |
300 | |
301 // Deallocate free metadata on the free list. How useful the PermGen was! | |
302 void ClassLoaderData::free_deallocate_list() { | |
303 // Don't need lock, at safepoint | |
304 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint"); | |
305 if (_deallocate_list == NULL) { | |
306 return; | |
307 } | |
308 // Go backwards because this removes entries that are freed. | |
309 for (int i = _deallocate_list->length() - 1; i >= 0; i--) { | |
310 Metadata* m = _deallocate_list->at(i); | |
311 if (!m->on_stack()) { | |
312 _deallocate_list->remove_at(i); | |
313 // There are only three types of metadata that we deallocate directly. | |
314 // Cast them so they can be used by the template function. | |
315 if (m->is_method()) { | |
316 MetadataFactory::free_metadata(this, (Method*)m); | |
317 } else if (m->is_constantPool()) { | |
318 MetadataFactory::free_metadata(this, (ConstantPool*)m); | |
319 } else if (m->is_klass()) { | |
320 MetadataFactory::free_metadata(this, (InstanceKlass*)m); | |
321 } else { | |
322 ShouldNotReachHere(); | |
323 } | |
324 } | |
325 } | |
326 } | |
327 | |
328 #ifndef PRODUCT | |
329 void ClassLoaderData::print_loader(ClassLoaderData *loader_data, outputStream* out) { | |
330 oop class_loader = loader_data->class_loader(); | |
331 out->print("%s", SystemDictionary::loader_name(class_loader)); | |
332 } | |
333 | |
334 // Define to dump klasses | |
335 #undef CLD_DUMP_KLASSES | |
336 | |
337 void ClassLoaderData::dump(outputStream * const out) { | |
338 ResourceMark rm; | |
339 out->print("ClassLoaderData CLD: "PTR_FORMAT", loader: "PTR_FORMAT", loader_klass: "PTR_FORMAT" %s {", | |
340 this, class_loader(), | |
341 class_loader() != NULL ? class_loader()->klass() : NULL, | |
342 class_loader() != NULL ? class_loader()->klass()->external_name() : "NULL"); | |
343 if (claimed()) out->print(" claimed "); | |
344 if (is_unloading()) out->print(" unloading "); | |
345 out->print(" handles " INTPTR_FORMAT, handles()); | |
346 out->cr(); | |
347 if (metaspace_or_null() != NULL) { | |
348 out->print_cr("metaspace: " PTR_FORMAT, metaspace_or_null()); | |
349 metaspace_or_null()->dump(out); | |
350 } else { | |
351 out->print_cr("metaspace: NULL"); | |
352 } | |
353 | |
354 #ifdef CLD_DUMP_KLASSES | |
355 if (Verbose) { | |
356 ResourceMark rm; | |
357 Klass* k = _klasses; | |
358 while (k != NULL) { | |
359 out->print_cr("klass "PTR_FORMAT", %s, CT: %d, MUT: %d", k, k->name()->as_C_string(), | |
360 k->has_modified_oops(), k->has_accumulated_modified_oops()); | |
361 k = k->next_link(); | |
362 } | |
363 } | |
364 #endif // CLD_DUMP_KLASSES | |
365 #undef CLD_DUMP_KLASSES | |
366 if (_jmethod_ids != NULL) { | |
367 Method::print_jmethod_ids(this, out); | |
368 } | |
369 out->print_cr("}"); | |
370 } | |
371 #endif // PRODUCT | |
372 | |
373 void ClassLoaderData::verify() { | |
374 oop cl = class_loader(); | |
375 | |
376 guarantee(this == class_loader_data(cl), "Must be the same"); | |
377 guarantee(cl != NULL || this == ClassLoaderData::the_null_class_loader_data(), "must be"); | |
378 | |
379 // Verify the integrity of the allocated space. | |
380 if (metaspace_or_null() != NULL) { | |
381 metaspace_or_null()->verify(); | |
382 } | |
383 | |
384 for (Klass* k = _klasses; k != NULL; k = k->next_link()) { | |
385 guarantee(k->class_loader_data() == this, "Must be the same"); | |
386 k->verify(); | |
387 } | |
388 } | |
389 | |
390 // GC root of class loader data created. | |
391 ClassLoaderData* ClassLoaderDataGraph::_head = NULL; | |
392 ClassLoaderData* ClassLoaderDataGraph::_unloading = NULL; | |
393 ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL; | |
394 | |
395 | |
396 // Add a new class loader data node to the list. Assign the newly created | |
397 // ClassLoaderData into the java/lang/ClassLoader object as a hidden field | |
398 ClassLoaderData* ClassLoaderDataGraph::add(ClassLoaderData** cld_addr, Handle loader_data) { | |
399 // Not assigned a class loader data yet. | |
400 // Create one. | |
401 ClassLoaderData* *list_head = &_head; | |
402 ClassLoaderData* next = _head; | |
403 ClassLoaderData* cld = new ClassLoaderData(loader_data); | |
404 | |
405 // First, Atomically set it. | |
406 ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL); | |
407 if (old != NULL) { | |
408 delete cld; | |
409 // Returns the data. | |
410 return old; | |
411 } | |
412 | |
413 // We won the race, and therefore the task of adding the data to the list of | |
414 // class loader data | |
415 do { | |
416 cld->set_next(next); | |
417 ClassLoaderData* exchanged = (ClassLoaderData*)Atomic::cmpxchg_ptr(cld, list_head, next); | |
418 if (exchanged == next) { | |
419 if (TraceClassLoaderData) { | |
420 tty->print("[ClassLoaderData: "); | |
421 tty->print("create class loader data "PTR_FORMAT, cld); | |
422 tty->print(" for instance "PTR_FORMAT" of ", cld->class_loader()); | |
423 loader_data->klass()->name()->print_symbol_on(tty); | |
424 tty->print_cr("]"); | |
425 } | |
426 return cld; | |
427 } | |
428 next = exchanged; | |
429 } while (true); | |
430 } | |
431 | |
432 void ClassLoaderDataGraph::oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { | |
433 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { | |
434 cld->oops_do(f, klass_closure, must_claim); | |
435 } | |
436 } | |
437 | |
438 void ClassLoaderDataGraph::always_strong_oops_do(OopClosure* f, KlassClosure* klass_closure, bool must_claim) { | |
439 if (ClassUnloading) { | |
440 ClassLoaderData::the_null_class_loader_data()->oops_do(f, klass_closure, must_claim); | |
441 } else { | |
442 ClassLoaderDataGraph::oops_do(f, klass_closure, must_claim); | |
443 } | |
444 } | |
445 | |
446 void ClassLoaderDataGraph::classes_do(KlassClosure* klass_closure) { | |
447 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { | |
448 cld->classes_do(klass_closure); | |
449 } | |
450 } | |
451 | |
452 GrowableArray<ClassLoaderData*>* ClassLoaderDataGraph::new_clds() { | |
453 assert(_head == NULL || _saved_head != NULL, "remember_new_clds(true) not called?"); | |
454 | |
455 GrowableArray<ClassLoaderData*>* array = new GrowableArray<ClassLoaderData*>(); | |
456 | |
457 // The CLDs in [_head, _saved_head] were all added during last call to remember_new_clds(true); | |
458 ClassLoaderData* curr = _head; | |
459 while (curr != _saved_head) { | |
460 if (!curr->claimed()) { | |
461 array->push(curr); | |
462 | |
463 if (TraceClassLoaderData) { | |
464 tty->print("[ClassLoaderData] found new CLD: "); | |
465 curr->print_value_on(tty); | |
466 tty->cr(); | |
467 } | |
468 } | |
469 | |
470 curr = curr->_next; | |
471 } | |
472 | |
473 return array; | |
474 } | |
475 | |
476 #ifndef PRODUCT | |
477 // for debugging and hsfind(x) | |
478 bool ClassLoaderDataGraph::contains(address x) { | |
479 // I think we need the _metaspace_lock taken here because the class loader | |
480 // data graph could be changing while we are walking it (new entries added, | |
481 // new entries being unloaded, etc). | |
482 if (DumpSharedSpaces) { | |
483 // There are only two metaspaces to worry about. | |
484 ClassLoaderData* ncld = ClassLoaderData::the_null_class_loader_data(); | |
485 return (ncld->ro_metaspace()->contains(x) || ncld->rw_metaspace()->contains(x)); | |
486 } | |
487 | |
488 if (UseSharedSpaces && MetaspaceShared::is_in_shared_space(x)) { | |
489 return true; | |
490 } | |
491 | |
492 for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) { | |
493 if (cld->metaspace_or_null() != NULL && cld->metaspace_or_null()->contains(x)) { | |
494 return true; | |
495 } | |
496 } | |
497 | |
498 // Could also be on an unloading list which is okay, ie. still allocated | |
499 // for a little while. | |
500 for (ClassLoaderData* ucld = _unloading; ucld != NULL; ucld = ucld->next()) { | |
501 if (ucld->metaspace_or_null() != NULL && ucld->metaspace_or_null()->contains(x)) { | |
502 return true; | |
503 } | |
504 } | |
505 return false; | |
506 } | |
507 | |
508 bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) { | |
509 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) { | |
510 if (loader_data == data) { | |
511 return true; | |
512 } | |
513 } | |
514 | |
515 return false; | |
516 } | |
517 #endif // PRODUCT | |
518 | |
519 // Move class loader data from main list to the unloaded list for unloading | |
520 // and deallocation later. | |
521 bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive) { | |
522 ClassLoaderData* data = _head; | |
523 ClassLoaderData* prev = NULL; | |
524 bool seen_dead_loader = false; | |
525 // mark metadata seen on the stack and code cache so we can delete | |
526 // unneeded entries. | |
527 bool has_redefined_a_class = JvmtiExport::has_redefined_a_class(); | |
528 MetadataOnStackMark md_on_stack; | |
529 while (data != NULL) { | |
530 if (data->class_loader() == NULL || is_alive->do_object_b(data->class_loader())) { | |
531 assert(data->claimed(), "class loader data must have been claimed"); | |
532 if (has_redefined_a_class) { | |
533 data->classes_do(InstanceKlass::purge_previous_versions); | |
534 } | |
535 data->free_deallocate_list(); | |
536 prev = data; | |
537 data = data->next(); | |
538 continue; | |
539 } | |
540 seen_dead_loader = true; | |
541 ClassLoaderData* dead = data; | |
542 dead->mark_for_unload(); | |
543 if (TraceClassLoaderData) { | |
544 tty->print("[ClassLoaderData: unload loader data "PTR_FORMAT, dead); | |
545 tty->print(" for instance "PTR_FORMAT" of ", dead->class_loader()); | |
546 dead->class_loader()->klass()->name()->print_symbol_on(tty); | |
547 tty->print_cr("]"); | |
548 } | |
549 data = data->next(); | |
550 // Remove from loader list. | |
551 if (prev != NULL) { | |
552 prev->set_next(data); | |
553 } else { | |
554 assert(dead == _head, "sanity check"); | |
555 _head = data; | |
556 } | |
557 dead->set_next(_unloading); | |
558 _unloading = dead; | |
559 } | |
560 return seen_dead_loader; | |
561 } | |
562 | |
563 void ClassLoaderDataGraph::purge() { | |
564 ClassLoaderData* list = _unloading; | |
565 _unloading = NULL; | |
566 ClassLoaderData* next = list; | |
567 while (next != NULL) { | |
568 ClassLoaderData* purge_me = next; | |
569 next = purge_me->next(); | |
570 delete purge_me; | |
571 } | |
572 } | |
573 | |
574 // CDS support | |
575 | |
576 // Global metaspaces for writing information to the shared archive. When | |
577 // application CDS is supported, we may need one per metaspace, so this | |
578 // sort of looks like it. | |
579 Metaspace* ClassLoaderData::_ro_metaspace = NULL; | |
580 Metaspace* ClassLoaderData::_rw_metaspace = NULL; | |
581 static bool _shared_metaspaces_initialized = false; | |
582 | |
583 // Initialize shared metaspaces (change to call from somewhere not lazily) | |
584 void ClassLoaderData::initialize_shared_metaspaces() { | |
585 assert(DumpSharedSpaces, "only use this for dumping shared spaces"); | |
586 assert(this == ClassLoaderData::the_null_class_loader_data(), | |
587 "only supported for null loader data for now"); | |
588 assert (!_shared_metaspaces_initialized, "only initialize once"); | |
589 MutexLockerEx ml(metaspace_lock(), Mutex::_no_safepoint_check_flag); | |
590 _ro_metaspace = new Metaspace(_metaspace_lock, SharedReadOnlySize/wordSize); | |
591 _rw_metaspace = new Metaspace(_metaspace_lock, SharedReadWriteSize/wordSize); | |
592 _shared_metaspaces_initialized = true; | |
593 } | |
594 | |
595 Metaspace* ClassLoaderData::ro_metaspace() { | |
596 assert(_ro_metaspace != NULL, "should already be initialized"); | |
597 return _ro_metaspace; | |
598 } | |
599 | |
600 Metaspace* ClassLoaderData::rw_metaspace() { | |
601 assert(_rw_metaspace != NULL, "should already be initialized"); | |
602 return _rw_metaspace; | |
603 } | |
604 | |
605 | |
606 ClassLoaderDataGraphMetaspaceIterator::ClassLoaderDataGraphMetaspaceIterator() { | |
607 _data = ClassLoaderDataGraph::_head; | |
608 } | |
609 | |
610 ClassLoaderDataGraphMetaspaceIterator::~ClassLoaderDataGraphMetaspaceIterator() {} | |
611 | |
612 #ifndef PRODUCT | |
613 // callable from debugger | |
614 extern "C" int print_loader_data_graph() { | |
615 ClassLoaderDataGraph::dump_on(tty); | |
616 return 0; | |
617 } | |
618 | |
619 void ClassLoaderDataGraph::verify() { | |
620 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) { | |
621 data->verify(); | |
622 } | |
623 } | |
624 | |
625 void ClassLoaderDataGraph::dump_on(outputStream * const out) { | |
626 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) { | |
627 data->dump(out); | |
628 } | |
629 MetaspaceAux::dump(out); | |
630 } | |
631 | |
632 void ClassLoaderData::print_value_on(outputStream* out) const { | |
633 if (class_loader() == NULL) { | |
634 out->print_cr("NULL class_loader"); | |
635 } else { | |
636 out->print("class loader "PTR_FORMAT, this); | |
637 class_loader()->print_value_on(out); | |
638 } | |
639 } | |
640 #endif // PRODUCT |