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 "logging/log.hpp"
32 #include "logging/logTag.hpp"
33 #include "memory/heapInspection.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "memory/universe.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "oops/reflectionAccessorImplKlassHelper.hpp"
38 #include "runtime/os.hpp"
39 #include "utilities/globalDefinitions.hpp"
40 #include "utilities/macros.hpp"
41 #include "utilities/stack.inline.hpp"
42
43 // HeapInspection
44
45 inline KlassInfoEntry::~KlassInfoEntry() {
46 if (_subclasses != NULL) {
47 delete _subclasses;
48 }
49 }
50
51 inline void KlassInfoEntry::add_subclass(KlassInfoEntry* cie) {
52 if (_subclasses == NULL) {
53 _subclasses = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<KlassInfoEntry*>(4, true);
54 }
55 _subclasses->append(cie);
56 }
57
58 int KlassInfoEntry::compare(KlassInfoEntry* e1, KlassInfoEntry* e2) {
59 if(e1->_instance_words > e2->_instance_words) {
60 return -1;
61 } else if(e1->_instance_words < e2->_instance_words) {
62 return 1;
63 }
64 // Sort alphabetically, note 'Z' < '[' < 'a', but it's better to group
65 // the array classes before all the instance classes.
66 ResourceMark rm;
67 const char* name1 = e1->klass()->external_name();
68 const char* name2 = e2->klass()->external_name();
69 bool d1 = (name1[0] == JVM_SIGNATURE_ARRAY);
70 bool d2 = (name2[0] == JVM_SIGNATURE_ARRAY);
71 if (d1 && !d2) {
72 return -1;
73 } else if (d2 && !d1) {
74 return 1;
75 } else {
76 return strcmp(name1, name2);
77 }
78 }
79
80 const char* KlassInfoEntry::name() const {
81 const char* name;
82 if (_klass->name() != NULL) {
83 name = _klass->external_name();
84 } else {
85 if (_klass == Universe::boolArrayKlassObj()) name = "<boolArrayKlass>"; else
86 if (_klass == Universe::charArrayKlassObj()) name = "<charArrayKlass>"; else
87 if (_klass == Universe::floatArrayKlassObj()) name = "<floatArrayKlass>"; else
88 if (_klass == Universe::doubleArrayKlassObj()) name = "<doubleArrayKlass>"; else
89 if (_klass == Universe::byteArrayKlassObj()) name = "<byteArrayKlass>"; else
90 if (_klass == Universe::shortArrayKlassObj()) name = "<shortArrayKlass>"; else
91 if (_klass == Universe::intArrayKlassObj()) name = "<intArrayKlass>"; else
92 if (_klass == Universe::longArrayKlassObj()) name = "<longArrayKlass>"; else
93 name = "<no name>";
94 }
95 return name;
96 }
97
98 void KlassInfoEntry::print_on(outputStream* st) const {
99 ResourceMark rm;
100
101 // simplify the formatting (ILP32 vs LP64) - always cast the numbers to 64-bit
102 ModuleEntry* module = _klass->module();
103 if (module->is_named()) {
104 st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s (%s@%s)",
105 (int64_t)_instance_count,
106 (uint64_t)_instance_words * HeapWordSize,
107 name(),
108 module->name()->as_C_string(),
109 module->version() != NULL ? module->version()->as_C_string() : "");
110 } else {
111 st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s",
112 (int64_t)_instance_count,
113 (uint64_t)_instance_words * HeapWordSize,
114 name());
115 }
116 }
117
118 KlassInfoEntry* KlassInfoBucket::lookup(Klass* const k) {
119 // Can happen if k is an archived class that we haven't loaded yet.
120 if (k->java_mirror_no_keepalive() == NULL) {
121 return NULL;
122 }
123
124 KlassInfoEntry* elt = _list;
125 while (elt != NULL) {
126 if (elt->is_equal(k)) {
127 return elt;
128 }
129 elt = elt->next();
130 }
131 elt = new (std::nothrow) KlassInfoEntry(k, list());
132 // We may be out of space to allocate the new entry.
133 if (elt != NULL) {
134 set_list(elt);
135 }
136 return elt;
137 }
138
139 void KlassInfoBucket::iterate(KlassInfoClosure* cic) {
140 KlassInfoEntry* elt = _list;
141 while (elt != NULL) {
142 cic->do_cinfo(elt);
143 elt = elt->next();
144 }
145 }
146
147 void KlassInfoBucket::empty() {
148 KlassInfoEntry* elt = _list;
149 _list = NULL;
150 while (elt != NULL) {
151 KlassInfoEntry* next = elt->next();
152 delete elt;
153 elt = next;
154 }
155 }
156
157 class KlassInfoTable::AllClassesFinder : public LockedClassesDo {
158 KlassInfoTable *_table;
159 public:
160 AllClassesFinder(KlassInfoTable* table) : _table(table) {}
161 virtual void do_klass(Klass* k) {
162 // This has the SIDE EFFECT of creating a KlassInfoEntry
163 // for <k>, if one doesn't exist yet.
164 _table->lookup(k);
165 }
166 };
167
168
169 KlassInfoTable::KlassInfoTable(bool add_all_classes) {
170 _size_of_instances_in_words = 0;
171 _ref = (HeapWord*) Universe::boolArrayKlassObj();
172 _buckets =
173 (KlassInfoBucket*) AllocateHeap(sizeof(KlassInfoBucket) * _num_buckets,
174 mtInternal, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
175 if (_buckets != NULL) {
176 for (int index = 0; index < _num_buckets; index++) {
177 _buckets[index].initialize();
178 }
179 if (add_all_classes) {
180 AllClassesFinder finder(this);
181 ClassLoaderDataGraph::classes_do(&finder);
182 }
183 }
184 }
185
186 KlassInfoTable::~KlassInfoTable() {
187 if (_buckets != NULL) {
188 for (int index = 0; index < _num_buckets; index++) {
189 _buckets[index].empty();
190 }
191 FREE_C_HEAP_ARRAY(KlassInfoBucket, _buckets);
192 _buckets = NULL;
193 }
194 }
195
196 uint KlassInfoTable::hash(const Klass* p) {
197 return (uint)(((uintptr_t)p - (uintptr_t)_ref) >> 2);
198 }
199
200 KlassInfoEntry* KlassInfoTable::lookup(Klass* k) {
201 uint idx = hash(k) % _num_buckets;
202 assert(_buckets != NULL, "Allocation failure should have been caught");
203 KlassInfoEntry* e = _buckets[idx].lookup(k);
204 // Lookup may fail if this is a new klass for which we
205 // could not allocate space for an new entry, or if it's
206 // an archived class that we haven't loaded yet.
207 assert(e == NULL || k == e->klass(), "must be equal");
208 return e;
209 }
210
211 // Return false if the entry could not be recorded on account
212 // of running out of space required to create a new entry.
213 bool KlassInfoTable::record_instance(const oop obj) {
214 Klass* k = obj->klass();
215 KlassInfoEntry* elt = lookup(k);
216 // elt may be NULL if it's a new klass for which we
217 // could not allocate space for a new entry in the hashtable.
218 if (elt != NULL) {
219 elt->set_count(elt->count() + 1);
220 elt->set_words(elt->words() + obj->size());
221 _size_of_instances_in_words += obj->size();
222 return true;
223 } else {
224 return false;
225 }
226 }
227
228 void KlassInfoTable::iterate(KlassInfoClosure* cic) {
229 assert(_buckets != NULL, "Allocation failure should have been caught");
230 for (int index = 0; index < _num_buckets; index++) {
231 _buckets[index].iterate(cic);
232 }
233 }
234
235 size_t KlassInfoTable::size_of_instances_in_words() const {
236 return _size_of_instances_in_words;
237 }
238
239 int KlassInfoHisto::sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2) {
240 return (*e1)->compare(*e1,*e2);
241 }
242
243 KlassInfoHisto::KlassInfoHisto(KlassInfoTable* cit) :
244 _cit(cit) {
245 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<KlassInfoEntry*>(_histo_initial_size, true);
246 }
247
248 KlassInfoHisto::~KlassInfoHisto() {
249 delete _elements;
250 }
251
252 void KlassInfoHisto::add(KlassInfoEntry* cie) {
253 elements()->append(cie);
254 }
255
256 void KlassInfoHisto::sort() {
257 elements()->sort(KlassInfoHisto::sort_helper);
258 }
259
260 void KlassInfoHisto::print_elements(outputStream* st) const {
261 // simplify the formatting (ILP32 vs LP64) - store the sum in 64-bit
262 int64_t total = 0;
263 uint64_t totalw = 0;
264 for(int i=0; i < elements()->length(); i++) {
265 st->print("%4d: ", i+1);
266 elements()->at(i)->print_on(st);
267 total += elements()->at(i)->count();
268 totalw += elements()->at(i)->words();
269 }
270 st->print_cr("Total " INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13),
271 total, totalw * HeapWordSize);
272 }
273
274 class HierarchyClosure : public KlassInfoClosure {
275 private:
276 GrowableArray<KlassInfoEntry*> *_elements;
277 public:
278 HierarchyClosure(GrowableArray<KlassInfoEntry*> *_elements) : _elements(_elements) {}
279
280 void do_cinfo(KlassInfoEntry* cie) {
281 // ignore array classes
282 if (cie->klass()->is_instance_klass()) {
283 _elements->append(cie);
284 }
285 }
286 };
287
288 void KlassHierarchy::print_class_hierarchy(outputStream* st, bool print_interfaces,
289 bool print_subclasses, char* classname) {
290 ResourceMark rm;
291 Stack <KlassInfoEntry*, mtClass> class_stack;
292 GrowableArray<KlassInfoEntry*> elements;
293
294 // Add all classes to the KlassInfoTable, which allows for quick lookup.
295 // A KlassInfoEntry will be created for each class.
296 KlassInfoTable cit(true);
297 if (cit.allocation_failed()) {
298 st->print_cr("ERROR: Ran out of C-heap; hierarchy not generated");
299 return;
300 }
301
302 // Add all created KlassInfoEntry instances to the elements array for easy
303 // iteration, and to allow each KlassInfoEntry instance to have a unique index.
304 HierarchyClosure hc(&elements);
305 cit.iterate(&hc);
306
307 for(int i = 0; i < elements.length(); i++) {
308 KlassInfoEntry* cie = elements.at(i);
309 Klass* super = cie->klass()->super();
310
311 // Set the index for the class.
312 cie->set_index(i + 1);
313
314 // Add the class to the subclass array of its superclass.
315 if (super != NULL) {
316 KlassInfoEntry* super_cie = cit.lookup(super);
317 assert(super_cie != NULL, "could not lookup superclass");
318 super_cie->add_subclass(cie);
319 }
320 }
321
322 // Set the do_print flag for each class that should be printed.
323 for(int i = 0; i < elements.length(); i++) {
324 KlassInfoEntry* cie = elements.at(i);
325 if (classname == NULL) {
326 // We are printing all classes.
327 cie->set_do_print(true);
328 } else {
329 // We are only printing the hierarchy of a specific class.
330 if (strcmp(classname, cie->klass()->external_name()) == 0) {
331 KlassHierarchy::set_do_print_for_class_hierarchy(cie, &cit, print_subclasses);
332 }
333 }
334 }
335
336 // Now we do a depth first traversal of the class hierachry. The class_stack will
337 // maintain the list of classes we still need to process. Start things off
338 // by priming it with java.lang.Object.
339 KlassInfoEntry* jlo_cie = cit.lookup(SystemDictionary::Object_klass());
340 assert(jlo_cie != NULL, "could not lookup java.lang.Object");
341 class_stack.push(jlo_cie);
342
343 // Repeatedly pop the top item off the stack, print its class info,
344 // and push all of its subclasses on to the stack. Do this until there
345 // are no classes left on the stack.
346 while (!class_stack.is_empty()) {
347 KlassInfoEntry* curr_cie = class_stack.pop();
348 if (curr_cie->do_print()) {
349 print_class(st, curr_cie, print_interfaces);
350 if (curr_cie->subclasses() != NULL) {
351 // Current class has subclasses, so push all of them onto the stack.
352 for (int i = 0; i < curr_cie->subclasses()->length(); i++) {
353 KlassInfoEntry* cie = curr_cie->subclasses()->at(i);
354 if (cie->do_print()) {
355 class_stack.push(cie);
356 }
357 }
358 }
359 }
360 }
361
362 st->flush();
363 }
364
365 // Sets the do_print flag for every superclass and subclass of the specified class.
366 void KlassHierarchy::set_do_print_for_class_hierarchy(KlassInfoEntry* cie, KlassInfoTable* cit,
367 bool print_subclasses) {
368 // Set do_print for all superclasses of this class.
369 Klass* super = ((InstanceKlass*)cie->klass())->java_super();
370 while (super != NULL) {
371 KlassInfoEntry* super_cie = cit->lookup(super);
372 super_cie->set_do_print(true);
373 super = super->super();
374 }
375
376 // Set do_print for this class and all of its subclasses.
377 Stack <KlassInfoEntry*, mtClass> class_stack;
378 class_stack.push(cie);
379 while (!class_stack.is_empty()) {
380 KlassInfoEntry* curr_cie = class_stack.pop();
381 curr_cie->set_do_print(true);
382 if (print_subclasses && curr_cie->subclasses() != NULL) {
383 // Current class has subclasses, so push all of them onto the stack.
384 for (int i = 0; i < curr_cie->subclasses()->length(); i++) {
385 KlassInfoEntry* cie = curr_cie->subclasses()->at(i);
386 class_stack.push(cie);
387 }
388 }
389 }
390 }
391
392 static void print_indent(outputStream* st, int indent) {
393 while (indent != 0) {
394 st->print("|");
395 indent--;
396 if (indent != 0) {
397 st->print(" ");
398 }
399 }
400 }
401
402 // Print the class name and its unique ClassLoader identifer.
403 static void print_classname(outputStream* st, Klass* klass) {
404 oop loader_oop = klass->class_loader_data()->class_loader();
405 st->print("%s/", klass->external_name());
406 if (loader_oop == NULL) {
407 st->print("null");
408 } else {
409 st->print(INTPTR_FORMAT, p2i(klass->class_loader_data()));
410 }
411 }
412
413 static void print_interface(outputStream* st, InstanceKlass* intf_klass, const char* intf_type, int indent) {
414 print_indent(st, indent);
415 st->print(" implements ");
416 print_classname(st, intf_klass);
417 st->print(" (%s intf)\n", intf_type);
418 }
419
420 void KlassHierarchy::print_class(outputStream* st, KlassInfoEntry* cie, bool print_interfaces) {
421 ResourceMark rm;
422 InstanceKlass* klass = (InstanceKlass*)cie->klass();
423 int indent = 0;
424
425 // Print indentation with proper indicators of superclass.
426 Klass* super = klass->super();
427 while (super != NULL) {
428 super = super->super();
429 indent++;
430 }
431 print_indent(st, indent);
432 if (indent != 0) st->print("--");
433
434 // Print the class name, its unique ClassLoader identifer, and if it is an interface.
435 print_classname(st, klass);
436 if (klass->is_interface()) {
437 st->print(" (intf)");
438 }
439 // Special treatment for generated core reflection accessor classes: print invocation target.
440 if (ReflectionAccessorImplKlassHelper::is_generated_accessor(klass)) {
441 st->print(" (invokes: ");
442 ReflectionAccessorImplKlassHelper::print_invocation_target(st, klass);
443 st->print(")");
444 }
445 st->print("\n");
446
447 // Print any interfaces the class has.
448 if (print_interfaces) {
449 Array<InstanceKlass*>* local_intfs = klass->local_interfaces();
450 Array<InstanceKlass*>* trans_intfs = klass->transitive_interfaces();
451 for (int i = 0; i < local_intfs->length(); i++) {
452 print_interface(st, local_intfs->at(i), "declared", indent);
453 }
454 for (int i = 0; i < trans_intfs->length(); i++) {
455 InstanceKlass* trans_interface = trans_intfs->at(i);
456 // Only print transitive interfaces if they are not also declared.
457 if (!local_intfs->contains(trans_interface)) {
458 print_interface(st, trans_interface, "inherited", indent);
459 }
460 }
461 }
462 }
463
464 void KlassInfoHisto::print_histo_on(outputStream* st) {
465 st->print_cr(" num #instances #bytes class name (module)");
466 st->print_cr("-------------------------------------------------------");
467 print_elements(st);
468 }
469
470 class HistoClosure : public KlassInfoClosure {
471 private:
472 KlassInfoHisto* _cih;
473 public:
474 HistoClosure(KlassInfoHisto* cih) : _cih(cih) {}
475
476 void do_cinfo(KlassInfoEntry* cie) {
477 _cih->add(cie);
478 }
479 };
480
481 class RecordInstanceClosure : public ObjectClosure {
482 private:
483 KlassInfoTable* _cit;
484 size_t _missed_count;
485 BoolObjectClosure* _filter;
486 public:
487 RecordInstanceClosure(KlassInfoTable* cit, BoolObjectClosure* filter) :
488 _cit(cit), _missed_count(0), _filter(filter) {}
489
490 void do_object(oop obj) {
491 if (should_visit(obj)) {
492 if (!_cit->record_instance(obj)) {
493 _missed_count++;
494 }
495 }
496 }
497
498 size_t missed_count() { return _missed_count; }
499
500 private:
501 bool should_visit(oop obj) {
502 return _filter == NULL || _filter->do_object_b(obj);
503 }
504 };
505
506 size_t HeapInspection::populate_table(KlassInfoTable* cit, BoolObjectClosure *filter) {
507 ResourceMark rm;
508
509 RecordInstanceClosure ric(cit, filter);
510 Universe::heap()->object_iterate(&ric);
511 return ric.missed_count();
512 }
513
514 void HeapInspection::heap_inspection(outputStream* st) {
515 ResourceMark rm;
516
517 KlassInfoTable cit(false);
518 if (!cit.allocation_failed()) {
519 // populate table with object allocation info
520 size_t missed_count = populate_table(&cit);
521 if (missed_count != 0) {
522 log_info(gc, classhisto)("WARNING: Ran out of C-heap; undercounted " SIZE_FORMAT
523 " total instances in data below",
524 missed_count);
525 }
526
527 // Sort and print klass instance info
528 KlassInfoHisto histo(&cit);
529 HistoClosure hc(&histo);
530
531 cit.iterate(&hc);
532
533 histo.sort();
534 histo.print_histo_on(st);
535 } else {
536 st->print_cr("ERROR: Ran out of C-heap; histogram not generated");
537 }
538 st->flush();
539 }
540
541 class FindInstanceClosure : public ObjectClosure {
542 private:
543 Klass* _klass;
544 GrowableArray<oop>* _result;
545
546 public:
547 FindInstanceClosure(Klass* k, GrowableArray<oop>* result) : _klass(k), _result(result) {};
548
549 void do_object(oop obj) {
550 if (obj->is_a(_klass)) {
551 // obj was read with AS_NO_KEEPALIVE, or equivalent.
552 // The object needs to be kept alive when it is published.
553 Universe::heap()->keep_alive(obj);
554
555 _result->append(obj);
556 }
557 }
558 };
559
560 void HeapInspection::find_instances_at_safepoint(Klass* k, GrowableArray<oop>* result) {
561 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
562 assert(Heap_lock->is_locked(), "should have the Heap_lock");
563
564 // Ensure that the heap is parsable
565 Universe::heap()->ensure_parsability(false); // no need to retire TALBs
566
567 // Iterate over objects in the heap
568 FindInstanceClosure fic(k, result);
569 Universe::heap()->object_iterate(&fic);
570 }