1 /*
2 * Copyright (c) 2002, 2020, 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 #include "precompiled.hpp"
26 #include "classfile/classLoaderData.inline.hpp"
27 #include "classfile/classLoaderDataGraph.hpp"
28 #include "classfile/moduleEntry.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "gc/shared/collectedHeap.hpp"
31 #include "memory/heapInspection.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "memory/universe.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "oops/reflectionAccessorImplKlassHelper.hpp"
36 #include "runtime/os.hpp"
37 #include "utilities/globalDefinitions.hpp"
38 #include "utilities/macros.hpp"
39 #include "utilities/stack.inline.hpp"
40
41 // HeapInspection
42
43 inline KlassInfoEntry::~KlassInfoEntry() {
44 if (_subclasses != NULL) {
45 delete _subclasses;
46 }
47 }
48
49 inline void KlassInfoEntry::add_subclass(KlassInfoEntry* cie) {
50 if (_subclasses == NULL) {
51 _subclasses = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<KlassInfoEntry*>(4, true);
52 }
53 _subclasses->append(cie);
54 }
55
56 int KlassInfoEntry::compare(KlassInfoEntry* e1, KlassInfoEntry* e2) {
57 if(e1->_instance_words > e2->_instance_words) {
58 return -1;
59 } else if(e1->_instance_words < e2->_instance_words) {
60 return 1;
61 }
62 // Sort alphabetically, note 'Z' < '[' < 'a', but it's better to group
63 // the array classes before all the instance classes.
64 ResourceMark rm;
65 const char* name1 = e1->klass()->external_name();
66 const char* name2 = e2->klass()->external_name();
67 bool d1 = (name1[0] == JVM_SIGNATURE_ARRAY);
68 bool d2 = (name2[0] == JVM_SIGNATURE_ARRAY);
69 if (d1 && !d2) {
70 return -1;
71 } else if (d2 && !d1) {
72 return 1;
73 } else {
74 return strcmp(name1, name2);
75 }
76 }
77
78 const char* KlassInfoEntry::name() const {
79 const char* name;
80 if (_klass->name() != NULL) {
81 name = _klass->external_name();
82 } else {
83 if (_klass == Universe::boolArrayKlassObj()) name = "<boolArrayKlass>"; else
84 if (_klass == Universe::charArrayKlassObj()) name = "<charArrayKlass>"; else
85 if (_klass == Universe::floatArrayKlassObj()) name = "<floatArrayKlass>"; else
86 if (_klass == Universe::doubleArrayKlassObj()) name = "<doubleArrayKlass>"; else
87 if (_klass == Universe::byteArrayKlassObj()) name = "<byteArrayKlass>"; else
88 if (_klass == Universe::shortArrayKlassObj()) name = "<shortArrayKlass>"; else
89 if (_klass == Universe::intArrayKlassObj()) name = "<intArrayKlass>"; else
90 if (_klass == Universe::longArrayKlassObj()) name = "<longArrayKlass>"; else
91 name = "<no name>";
92 }
93 return name;
94 }
95
96 void KlassInfoEntry::print_on(outputStream* st) const {
97 ResourceMark rm;
98
99 // simplify the formatting (ILP32 vs LP64) - always cast the numbers to 64-bit
100 ModuleEntry* module = _klass->module();
101 if (module->is_named()) {
102 st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s (%s@%s)",
103 (int64_t)_instance_count,
104 (uint64_t)_instance_words * HeapWordSize,
105 name(),
106 module->name()->as_C_string(),
107 module->version() != NULL ? module->version()->as_C_string() : "");
108 } else {
109 st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s",
110 (int64_t)_instance_count,
111 (uint64_t)_instance_words * HeapWordSize,
112 name());
113 }
114 }
115
116 KlassInfoEntry* KlassInfoBucket::lookup(Klass* const k) {
117 // Can happen if k is an archived class that we haven't loaded yet.
118 if (k->java_mirror_no_keepalive() == NULL) {
119 return NULL;
120 }
121
122 KlassInfoEntry* elt = _list;
123 while (elt != NULL) {
124 if (elt->is_equal(k)) {
125 return elt;
126 }
127 elt = elt->next();
128 }
129 elt = new (std::nothrow) KlassInfoEntry(k, list());
130 // We may be out of space to allocate the new entry.
131 if (elt != NULL) {
132 set_list(elt);
133 }
134 return elt;
135 }
136
137 void KlassInfoBucket::iterate(KlassInfoClosure* cic) {
138 KlassInfoEntry* elt = _list;
139 while (elt != NULL) {
140 cic->do_cinfo(elt);
141 elt = elt->next();
142 }
143 }
144
145 void KlassInfoBucket::empty() {
146 KlassInfoEntry* elt = _list;
147 _list = NULL;
148 while (elt != NULL) {
149 KlassInfoEntry* next = elt->next();
150 delete elt;
151 elt = next;
152 }
153 }
154
155 class KlassInfoTable::AllClassesFinder : public LockedClassesDo {
156 KlassInfoTable *_table;
157 public:
158 AllClassesFinder(KlassInfoTable* table) : _table(table) {}
159 virtual void do_klass(Klass* k) {
160 // This has the SIDE EFFECT of creating a KlassInfoEntry
161 // for <k>, if one doesn't exist yet.
162 _table->lookup(k);
163 }
164 };
165
166
167 KlassInfoTable::KlassInfoTable(bool add_all_classes) {
168 _size_of_instances_in_words = 0;
169 _ref = (HeapWord*) Universe::boolArrayKlassObj();
170 _buckets =
171 (KlassInfoBucket*) AllocateHeap(sizeof(KlassInfoBucket) * _num_buckets,
172 mtInternal, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
173 if (_buckets != NULL) {
174 for (int index = 0; index < _num_buckets; index++) {
175 _buckets[index].initialize();
176 }
177 if (add_all_classes) {
178 AllClassesFinder finder(this);
179 ClassLoaderDataGraph::classes_do(&finder);
180 }
181 }
182 }
183
184 KlassInfoTable::~KlassInfoTable() {
185 if (_buckets != NULL) {
186 for (int index = 0; index < _num_buckets; index++) {
187 _buckets[index].empty();
188 }
189 FREE_C_HEAP_ARRAY(KlassInfoBucket, _buckets);
190 _buckets = NULL;
191 }
192 }
193
194 uint KlassInfoTable::hash(const Klass* p) {
195 return (uint)(((uintptr_t)p - (uintptr_t)_ref) >> 2);
196 }
197
198 KlassInfoEntry* KlassInfoTable::lookup(Klass* k) {
199 uint idx = hash(k) % _num_buckets;
200 assert(_buckets != NULL, "Allocation failure should have been caught");
201 KlassInfoEntry* e = _buckets[idx].lookup(k);
202 // Lookup may fail if this is a new klass for which we
203 // could not allocate space for an new entry, or if it's
204 // an archived class that we haven't loaded yet.
205 assert(e == NULL || k == e->klass(), "must be equal");
206 return e;
207 }
208
209 // Return false if the entry could not be recorded on account
210 // of running out of space required to create a new entry.
211 bool KlassInfoTable::record_instance(const oop obj) {
212 Klass* k = obj->klass();
213 KlassInfoEntry* elt = lookup(k);
214 // elt may be NULL if it's a new klass for which we
215 // could not allocate space for a new entry in the hashtable.
216 if (elt != NULL) {
217 elt->set_count(elt->count() + 1);
218 elt->set_words(elt->words() + obj->size());
219 _size_of_instances_in_words += obj->size();
220 return true;
221 } else {
222 return false;
223 }
224 }
225
226 void KlassInfoTable::iterate(KlassInfoClosure* cic) {
227 assert(_buckets != NULL, "Allocation failure should have been caught");
228 for (int index = 0; index < _num_buckets; index++) {
229 _buckets[index].iterate(cic);
230 }
231 }
232
233 size_t KlassInfoTable::size_of_instances_in_words() const {
234 return _size_of_instances_in_words;
235 }
236
237 int KlassInfoHisto::sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2) {
238 return (*e1)->compare(*e1,*e2);
239 }
240
241 KlassInfoHisto::KlassInfoHisto(KlassInfoTable* cit) :
242 _cit(cit) {
243 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<KlassInfoEntry*>(_histo_initial_size, true);
244 }
245
246 KlassInfoHisto::~KlassInfoHisto() {
247 delete _elements;
248 }
249
250 void KlassInfoHisto::add(KlassInfoEntry* cie) {
251 elements()->append(cie);
252 }
253
254 void KlassInfoHisto::sort() {
255 elements()->sort(KlassInfoHisto::sort_helper);
256 }
257
258 void KlassInfoHisto::print_elements(outputStream* st) const {
259 // simplify the formatting (ILP32 vs LP64) - store the sum in 64-bit
260 int64_t total = 0;
261 uint64_t totalw = 0;
262 for(int i=0; i < elements()->length(); i++) {
263 st->print("%4d: ", i+1);
264 elements()->at(i)->print_on(st);
265 total += elements()->at(i)->count();
266 totalw += elements()->at(i)->words();
267 }
268 st->print_cr("Total " INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13),
269 total, totalw * HeapWordSize);
270 }
271
272 class HierarchyClosure : public KlassInfoClosure {
273 private:
274 GrowableArray<KlassInfoEntry*> *_elements;
275 public:
276 HierarchyClosure(GrowableArray<KlassInfoEntry*> *_elements) : _elements(_elements) {}
277
278 void do_cinfo(KlassInfoEntry* cie) {
279 // ignore array classes
280 if (cie->klass()->is_instance_klass()) {
281 _elements->append(cie);
282 }
283 }
284 };
285
286 void KlassHierarchy::print_class_hierarchy(outputStream* st, bool print_interfaces,
287 bool print_subclasses, char* classname) {
288 ResourceMark rm;
289 Stack <KlassInfoEntry*, mtClass> class_stack;
290 GrowableArray<KlassInfoEntry*> elements;
291
292 // Add all classes to the KlassInfoTable, which allows for quick lookup.
293 // A KlassInfoEntry will be created for each class.
294 KlassInfoTable cit(true);
295 if (cit.allocation_failed()) {
296 st->print_cr("ERROR: Ran out of C-heap; hierarchy not generated");
297 return;
298 }
299
300 // Add all created KlassInfoEntry instances to the elements array for easy
301 // iteration, and to allow each KlassInfoEntry instance to have a unique index.
302 HierarchyClosure hc(&elements);
303 cit.iterate(&hc);
304
305 for(int i = 0; i < elements.length(); i++) {
306 KlassInfoEntry* cie = elements.at(i);
307 Klass* super = cie->klass()->super();
308
309 // Set the index for the class.
310 cie->set_index(i + 1);
311
312 // Add the class to the subclass array of its superclass.
313 if (super != NULL) {
314 KlassInfoEntry* super_cie = cit.lookup(super);
315 assert(super_cie != NULL, "could not lookup superclass");
316 super_cie->add_subclass(cie);
317 }
318 }
319
320 // Set the do_print flag for each class that should be printed.
321 for(int i = 0; i < elements.length(); i++) {
322 KlassInfoEntry* cie = elements.at(i);
323 if (classname == NULL) {
324 // We are printing all classes.
325 cie->set_do_print(true);
326 } else {
327 // We are only printing the hierarchy of a specific class.
328 if (strcmp(classname, cie->klass()->external_name()) == 0) {
329 KlassHierarchy::set_do_print_for_class_hierarchy(cie, &cit, print_subclasses);
330 }
331 }
332 }
333
334 // Now we do a depth first traversal of the class hierachry. The class_stack will
335 // maintain the list of classes we still need to process. Start things off
336 // by priming it with java.lang.Object.
337 KlassInfoEntry* jlo_cie = cit.lookup(SystemDictionary::Object_klass());
338 assert(jlo_cie != NULL, "could not lookup java.lang.Object");
339 class_stack.push(jlo_cie);
340
341 // Repeatedly pop the top item off the stack, print its class info,
342 // and push all of its subclasses on to the stack. Do this until there
343 // are no classes left on the stack.
344 while (!class_stack.is_empty()) {
345 KlassInfoEntry* curr_cie = class_stack.pop();
346 if (curr_cie->do_print()) {
347 print_class(st, curr_cie, print_interfaces);
348 if (curr_cie->subclasses() != NULL) {
349 // Current class has subclasses, so push all of them onto the stack.
350 for (int i = 0; i < curr_cie->subclasses()->length(); i++) {
351 KlassInfoEntry* cie = curr_cie->subclasses()->at(i);
352 if (cie->do_print()) {
353 class_stack.push(cie);
354 }
355 }
356 }
357 }
358 }
359
360 st->flush();
361 }
362
363 // Sets the do_print flag for every superclass and subclass of the specified class.
364 void KlassHierarchy::set_do_print_for_class_hierarchy(KlassInfoEntry* cie, KlassInfoTable* cit,
365 bool print_subclasses) {
366 // Set do_print for all superclasses of this class.
367 Klass* super = ((InstanceKlass*)cie->klass())->java_super();
368 while (super != NULL) {
369 KlassInfoEntry* super_cie = cit->lookup(super);
370 super_cie->set_do_print(true);
371 super = super->super();
372 }
373
374 // Set do_print for this class and all of its subclasses.
375 Stack <KlassInfoEntry*, mtClass> class_stack;
376 class_stack.push(cie);
377 while (!class_stack.is_empty()) {
378 KlassInfoEntry* curr_cie = class_stack.pop();
379 curr_cie->set_do_print(true);
380 if (print_subclasses && curr_cie->subclasses() != NULL) {
381 // Current class has subclasses, so push all of them onto the stack.
382 for (int i = 0; i < curr_cie->subclasses()->length(); i++) {
383 KlassInfoEntry* cie = curr_cie->subclasses()->at(i);
384 class_stack.push(cie);
385 }
386 }
387 }
388 }
389
390 static void print_indent(outputStream* st, int indent) {
391 while (indent != 0) {
392 st->print("|");
393 indent--;
394 if (indent != 0) {
395 st->print(" ");
396 }
397 }
398 }
399
400 // Print the class name and its unique ClassLoader identifer.
401 static void print_classname(outputStream* st, Klass* klass) {
402 oop loader_oop = klass->class_loader_data()->class_loader();
403 st->print("%s/", klass->external_name());
404 if (loader_oop == NULL) {
405 st->print("null");
406 } else {
407 st->print(INTPTR_FORMAT, p2i(klass->class_loader_data()));
408 }
409 }
410
411 static void print_interface(outputStream* st, InstanceKlass* intf_klass, const char* intf_type, int indent) {
412 print_indent(st, indent);
413 st->print(" implements ");
414 print_classname(st, intf_klass);
415 st->print(" (%s intf)\n", intf_type);
416 }
417
418 void KlassHierarchy::print_class(outputStream* st, KlassInfoEntry* cie, bool print_interfaces) {
419 ResourceMark rm;
420 InstanceKlass* klass = (InstanceKlass*)cie->klass();
421 int indent = 0;
422
423 // Print indentation with proper indicators of superclass.
424 Klass* super = klass->super();
425 while (super != NULL) {
426 super = super->super();
427 indent++;
428 }
429 print_indent(st, indent);
430 if (indent != 0) st->print("--");
431
432 // Print the class name, its unique ClassLoader identifer, and if it is an interface.
433 print_classname(st, klass);
434 if (klass->is_interface()) {
435 st->print(" (intf)");
436 }
437 // Special treatment for generated core reflection accessor classes: print invocation target.
438 if (ReflectionAccessorImplKlassHelper::is_generated_accessor(klass)) {
439 st->print(" (invokes: ");
440 ReflectionAccessorImplKlassHelper::print_invocation_target(st, klass);
441 st->print(")");
442 }
443 st->print("\n");
444
445 // Print any interfaces the class has.
446 if (print_interfaces) {
447 Array<InstanceKlass*>* local_intfs = klass->local_interfaces();
448 Array<InstanceKlass*>* trans_intfs = klass->transitive_interfaces();
449 for (int i = 0; i < local_intfs->length(); i++) {
450 print_interface(st, local_intfs->at(i), "declared", indent);
451 }
452 for (int i = 0; i < trans_intfs->length(); i++) {
453 InstanceKlass* trans_interface = trans_intfs->at(i);
454 // Only print transitive interfaces if they are not also declared.
455 if (!local_intfs->contains(trans_interface)) {
456 print_interface(st, trans_interface, "inherited", indent);
457 }
458 }
459 }
460 }
461
462 void KlassInfoHisto::print_histo_on(outputStream* st) {
463 st->print_cr(" num #instances #bytes class name (module)");
464 st->print_cr("-------------------------------------------------------");
465 print_elements(st);
466 }
467
468 class HistoClosure : public KlassInfoClosure {
469 private:
470 KlassInfoHisto* _cih;
471 public:
472 HistoClosure(KlassInfoHisto* cih) : _cih(cih) {}
473
474 void do_cinfo(KlassInfoEntry* cie) {
475 _cih->add(cie);
476 }
477 };
478
479 class RecordInstanceClosure : public ObjectClosure {
480 private:
481 KlassInfoTable* _cit;
482 size_t _missed_count;
483 BoolObjectClosure* _filter;
484 public:
485 RecordInstanceClosure(KlassInfoTable* cit, BoolObjectClosure* filter) :
486 _cit(cit), _missed_count(0), _filter(filter) {}
487
488 void do_object(oop obj) {
489 if (should_visit(obj)) {
490 if (!_cit->record_instance(obj)) {
491 _missed_count++;
492 }
493 }
494 }
495
496 size_t missed_count() { return _missed_count; }
497
498 private:
499 bool should_visit(oop obj) {
500 return _filter == NULL || _filter->do_object_b(obj);
501 }
502 };
503
504 size_t HeapInspection::populate_table(KlassInfoTable* cit, BoolObjectClosure *filter) {
505 ResourceMark rm;
506
507 RecordInstanceClosure ric(cit, filter);
508 Universe::heap()->object_iterate(&ric);
509 return ric.missed_count();
510 }
511
512 void HeapInspection::heap_inspection(outputStream* st) {
513 ResourceMark rm;
514
515 KlassInfoTable cit(true);
516 if (!cit.allocation_failed()) {
517 // populate table with object allocation info
518 size_t missed_count = populate_table(&cit);
519 if (missed_count != 0) {
520 st->print_cr("WARNING: Ran out of C-heap; undercounted " SIZE_FORMAT
521 " total instances in data below",
522 missed_count);
523 }
524
525 // Sort and print klass instance info
526 KlassInfoHisto histo(&cit);
527 HistoClosure hc(&histo);
528
529 cit.iterate(&hc);
530
531 histo.sort();
532 histo.print_histo_on(st);
533 } else {
534 st->print_cr("ERROR: Ran out of C-heap; histogram not generated");
535 }
536 st->flush();
537 }
538
539 class FindInstanceClosure : public ObjectClosure {
540 private:
541 Klass* _klass;
542 GrowableArray<oop>* _result;
543
544 public:
545 FindInstanceClosure(Klass* k, GrowableArray<oop>* result) : _klass(k), _result(result) {};
546
547 void do_object(oop obj) {
548 if (obj->is_a(_klass)) {
549 // obj was read with AS_NO_KEEPALIVE, or equivalent.
550 // The object needs to be kept alive when it is published.
551 Universe::heap()->keep_alive(obj);
552
553 _result->append(obj);
554 }
555 }
556 };
557
558 void HeapInspection::find_instances_at_safepoint(Klass* k, GrowableArray<oop>* result) {
559 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
560 assert(Heap_lock->is_locked(), "should have the Heap_lock");
561
562 // Ensure that the heap is parsable
563 Universe::heap()->ensure_parsability(false); // no need to retire TALBs
564
565 // Iterate over objects in the heap
566 FindInstanceClosure fic(k, result);
567 Universe::heap()->object_iterate(&fic);
568 }
--- EOF ---