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/atomic.hpp" 39 #include "runtime/os.hpp" 40 #include "utilities/globalDefinitions.hpp" 41 #include "utilities/macros.hpp" 42 #include "utilities/stack.inline.hpp" 43 44 // HeapInspection 45 46 inline KlassInfoEntry::~KlassInfoEntry() { 47 if (_subclasses != NULL) { 48 delete _subclasses; 49 } 50 } 51 52 inline void KlassInfoEntry::add_subclass(KlassInfoEntry* cie) { 53 if (_subclasses == NULL) { 54 _subclasses = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<KlassInfoEntry*>(4, true); 55 } 56 _subclasses->append(cie); 57 } 58 59 int KlassInfoEntry::compare(KlassInfoEntry* e1, KlassInfoEntry* e2) { 60 if(e1->_instance_words > e2->_instance_words) { 61 return -1; 62 } else if(e1->_instance_words < e2->_instance_words) { 63 return 1; 64 } 65 // Sort alphabetically, note 'Z' < '[' < 'a', but it's better to group 66 // the array classes before all the instance classes. 67 ResourceMark rm; 68 const char* name1 = e1->klass()->external_name(); 69 const char* name2 = e2->klass()->external_name(); 70 bool d1 = (name1[0] == JVM_SIGNATURE_ARRAY); 71 bool d2 = (name2[0] == JVM_SIGNATURE_ARRAY); 72 if (d1 && !d2) { 73 return -1; 74 } else if (d2 && !d1) { 75 return 1; 76 } else { 77 return strcmp(name1, name2); 78 } 79 } 80 81 const char* KlassInfoEntry::name() const { 82 const char* name; 83 if (_klass->name() != NULL) { 84 name = _klass->external_name(); 85 } else { 86 if (_klass == Universe::boolArrayKlassObj()) name = "<boolArrayKlass>"; else 87 if (_klass == Universe::charArrayKlassObj()) name = "<charArrayKlass>"; else 88 if (_klass == Universe::floatArrayKlassObj()) name = "<floatArrayKlass>"; else 89 if (_klass == Universe::doubleArrayKlassObj()) name = "<doubleArrayKlass>"; else 90 if (_klass == Universe::byteArrayKlassObj()) name = "<byteArrayKlass>"; else 91 if (_klass == Universe::shortArrayKlassObj()) name = "<shortArrayKlass>"; else 92 if (_klass == Universe::intArrayKlassObj()) name = "<intArrayKlass>"; else 93 if (_klass == Universe::longArrayKlassObj()) name = "<longArrayKlass>"; else 94 name = "<no name>"; 95 } 96 return name; 97 } 98 99 void KlassInfoEntry::print_on(outputStream* st) const { 100 ResourceMark rm; 101 102 // simplify the formatting (ILP32 vs LP64) - always cast the numbers to 64-bit 103 ModuleEntry* module = _klass->module(); 104 if (module->is_named()) { 105 st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s (%s%s%s)", 106 (int64_t)_instance_count, 107 (uint64_t)_instance_words * HeapWordSize, 108 name(), 109 module->name()->as_C_string(), 110 module->version() != NULL ? "@" : "", 111 module->version() != NULL ? module->version()->as_C_string() : ""); 112 } else { 113 st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s", 114 (int64_t)_instance_count, 115 (uint64_t)_instance_words * HeapWordSize, 116 name()); 117 } 118 } 119 120 KlassInfoEntry* KlassInfoBucket::lookup(Klass* const k) { 121 // Can happen if k is an archived class that we haven't loaded yet. 122 if (k->java_mirror_no_keepalive() == NULL) { 123 return NULL; 124 } 125 126 KlassInfoEntry* elt = _list; 127 while (elt != NULL) { 128 if (elt->is_equal(k)) { 129 return elt; 130 } 131 elt = elt->next(); 132 } 133 elt = new (std::nothrow) KlassInfoEntry(k, list()); 134 // We may be out of space to allocate the new entry. 135 if (elt != NULL) { 136 set_list(elt); 137 } 138 return elt; 139 } 140 141 void KlassInfoBucket::iterate(KlassInfoClosure* cic) { 142 KlassInfoEntry* elt = _list; 143 while (elt != NULL) { 144 cic->do_cinfo(elt); 145 elt = elt->next(); 146 } 147 } 148 149 void KlassInfoBucket::empty() { 150 KlassInfoEntry* elt = _list; 151 _list = NULL; 152 while (elt != NULL) { 153 KlassInfoEntry* next = elt->next(); 154 delete elt; 155 elt = next; 156 } 157 } 158 159 class KlassInfoTable::AllClassesFinder : public LockedClassesDo { 160 KlassInfoTable *_table; 161 public: 162 AllClassesFinder(KlassInfoTable* table) : _table(table) {} 163 virtual void do_klass(Klass* k) { 164 // This has the SIDE EFFECT of creating a KlassInfoEntry 165 // for <k>, if one doesn't exist yet. 166 _table->lookup(k); 167 } 168 }; 169 170 171 KlassInfoTable::KlassInfoTable(bool add_all_classes) { 172 _size_of_instances_in_words = 0; 173 _ref = (HeapWord*) Universe::boolArrayKlassObj(); 174 _buckets = 175 (KlassInfoBucket*) AllocateHeap(sizeof(KlassInfoBucket) * _num_buckets, 176 mtInternal, CURRENT_PC, AllocFailStrategy::RETURN_NULL); 177 if (_buckets != NULL) { 178 for (int index = 0; index < _num_buckets; index++) { 179 _buckets[index].initialize(); 180 } 181 if (add_all_classes) { 182 AllClassesFinder finder(this); 183 ClassLoaderDataGraph::classes_do(&finder); 184 } 185 } 186 } 187 188 KlassInfoTable::~KlassInfoTable() { 189 if (_buckets != NULL) { 190 for (int index = 0; index < _num_buckets; index++) { 191 _buckets[index].empty(); 192 } 193 FREE_C_HEAP_ARRAY(KlassInfoBucket, _buckets); 194 _buckets = NULL; 195 } 196 } 197 198 uint KlassInfoTable::hash(const Klass* p) { 199 return (uint)(((uintptr_t)p - (uintptr_t)_ref) >> 2); 200 } 201 202 KlassInfoEntry* KlassInfoTable::lookup(Klass* k) { 203 uint idx = hash(k) % _num_buckets; 204 assert(_buckets != NULL, "Allocation failure should have been caught"); 205 KlassInfoEntry* e = _buckets[idx].lookup(k); 206 // Lookup may fail if this is a new klass for which we 207 // could not allocate space for an new entry, or if it's 208 // an archived class that we haven't loaded yet. 209 assert(e == NULL || k == e->klass(), "must be equal"); 210 return e; 211 } 212 213 // Return false if the entry could not be recorded on account 214 // of running out of space required to create a new entry. 215 bool KlassInfoTable::record_instance(const oop obj) { 216 Klass* k = obj->klass(); 217 KlassInfoEntry* elt = lookup(k); 218 // elt may be NULL if it's a new klass for which we 219 // could not allocate space for a new entry in the hashtable. 220 if (elt != NULL) { 221 elt->set_count(elt->count() + 1); 222 elt->set_words(elt->words() + obj->size()); 223 _size_of_instances_in_words += obj->size(); 224 return true; 225 } else { 226 return false; 227 } 228 } 229 230 void KlassInfoTable::iterate(KlassInfoClosure* cic) { 231 assert(_buckets != NULL, "Allocation failure should have been caught"); 232 for (int index = 0; index < _num_buckets; index++) { 233 _buckets[index].iterate(cic); 234 } 235 } 236 237 size_t KlassInfoTable::size_of_instances_in_words() const { 238 return _size_of_instances_in_words; 239 } 240 241 // Return false if the entry could not be recorded on account 242 // of running out of space required to create a new entry. 243 bool KlassInfoTable::merge_entry(const KlassInfoEntry* cie) { 244 Klass* k = cie->klass(); 245 KlassInfoEntry* elt = lookup(k); 246 // elt may be NULL if it's a new klass for which we 247 // could not allocate space for a new entry in the hashtable. 248 if (elt != NULL) { 249 elt->set_count(elt->count() + cie->count()); 250 elt->set_words(elt->words() + cie->words()); 251 _size_of_instances_in_words += cie->words(); 252 return true; 253 } else { 254 return false; 255 } 256 } 257 258 class KlassInfoTableMergeClosure : public KlassInfoClosure { 259 private: 260 KlassInfoTable* _dest; 261 bool _success; 262 public: 263 KlassInfoTableMergeClosure(KlassInfoTable* table) : _dest(table), _success(true) {} 264 void do_cinfo(KlassInfoEntry* cie) { 265 _success &= _dest->merge_entry(cie); 266 } 267 bool is_success() { return _success; } 268 }; 269 270 // merge from table 271 bool KlassInfoTable::merge(KlassInfoTable* table) { 272 KlassInfoTableMergeClosure closure(this); 273 table->iterate(&closure); 274 return closure.is_success(); 275 } 276 277 int KlassInfoHisto::sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2) { 278 return (*e1)->compare(*e1,*e2); 279 } 280 281 KlassInfoHisto::KlassInfoHisto(KlassInfoTable* cit) : 282 _cit(cit) { 283 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<KlassInfoEntry*>(_histo_initial_size, true); 284 } 285 286 KlassInfoHisto::~KlassInfoHisto() { 287 delete _elements; 288 } 289 290 void KlassInfoHisto::add(KlassInfoEntry* cie) { 291 elements()->append(cie); 292 } 293 294 void KlassInfoHisto::sort() { 295 elements()->sort(KlassInfoHisto::sort_helper); 296 } 297 298 void KlassInfoHisto::print_elements(outputStream* st) const { 299 // simplify the formatting (ILP32 vs LP64) - store the sum in 64-bit 300 int64_t total = 0; 301 uint64_t totalw = 0; 302 for(int i=0; i < elements()->length(); i++) { 303 st->print("%4d: ", i+1); 304 elements()->at(i)->print_on(st); 305 total += elements()->at(i)->count(); 306 totalw += elements()->at(i)->words(); 307 } 308 st->print_cr("Total " INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13), 309 total, totalw * HeapWordSize); 310 } 311 312 class HierarchyClosure : public KlassInfoClosure { 313 private: 314 GrowableArray<KlassInfoEntry*> *_elements; 315 public: 316 HierarchyClosure(GrowableArray<KlassInfoEntry*> *_elements) : _elements(_elements) {} 317 318 void do_cinfo(KlassInfoEntry* cie) { 319 // ignore array classes 320 if (cie->klass()->is_instance_klass()) { 321 _elements->append(cie); 322 } 323 } 324 }; 325 326 void KlassHierarchy::print_class_hierarchy(outputStream* st, bool print_interfaces, 327 bool print_subclasses, char* classname) { 328 ResourceMark rm; 329 Stack <KlassInfoEntry*, mtClass> class_stack; 330 GrowableArray<KlassInfoEntry*> elements; 331 332 // Add all classes to the KlassInfoTable, which allows for quick lookup. 333 // A KlassInfoEntry will be created for each class. 334 KlassInfoTable cit(true); 335 if (cit.allocation_failed()) { 336 st->print_cr("ERROR: Ran out of C-heap; hierarchy not generated"); 337 return; 338 } 339 340 // Add all created KlassInfoEntry instances to the elements array for easy 341 // iteration, and to allow each KlassInfoEntry instance to have a unique index. 342 HierarchyClosure hc(&elements); 343 cit.iterate(&hc); 344 345 for(int i = 0; i < elements.length(); i++) { 346 KlassInfoEntry* cie = elements.at(i); 347 Klass* super = cie->klass()->super(); 348 349 // Set the index for the class. 350 cie->set_index(i + 1); 351 352 // Add the class to the subclass array of its superclass. 353 if (super != NULL) { 354 KlassInfoEntry* super_cie = cit.lookup(super); 355 assert(super_cie != NULL, "could not lookup superclass"); 356 super_cie->add_subclass(cie); 357 } 358 } 359 360 // Set the do_print flag for each class that should be printed. 361 for(int i = 0; i < elements.length(); i++) { 362 KlassInfoEntry* cie = elements.at(i); 363 if (classname == NULL) { 364 // We are printing all classes. 365 cie->set_do_print(true); 366 } else { 367 // We are only printing the hierarchy of a specific class. 368 if (strcmp(classname, cie->klass()->external_name()) == 0) { 369 KlassHierarchy::set_do_print_for_class_hierarchy(cie, &cit, print_subclasses); 370 } 371 } 372 } 373 374 // Now we do a depth first traversal of the class hierachry. The class_stack will 375 // maintain the list of classes we still need to process. Start things off 376 // by priming it with java.lang.Object. 377 KlassInfoEntry* jlo_cie = cit.lookup(SystemDictionary::Object_klass()); 378 assert(jlo_cie != NULL, "could not lookup java.lang.Object"); 379 class_stack.push(jlo_cie); 380 381 // Repeatedly pop the top item off the stack, print its class info, 382 // and push all of its subclasses on to the stack. Do this until there 383 // are no classes left on the stack. 384 while (!class_stack.is_empty()) { 385 KlassInfoEntry* curr_cie = class_stack.pop(); 386 if (curr_cie->do_print()) { 387 print_class(st, curr_cie, print_interfaces); 388 if (curr_cie->subclasses() != NULL) { 389 // Current class has subclasses, so push all of them onto the stack. 390 for (int i = 0; i < curr_cie->subclasses()->length(); i++) { 391 KlassInfoEntry* cie = curr_cie->subclasses()->at(i); 392 if (cie->do_print()) { 393 class_stack.push(cie); 394 } 395 } 396 } 397 } 398 } 399 400 st->flush(); 401 } 402 403 // Sets the do_print flag for every superclass and subclass of the specified class. 404 void KlassHierarchy::set_do_print_for_class_hierarchy(KlassInfoEntry* cie, KlassInfoTable* cit, 405 bool print_subclasses) { 406 // Set do_print for all superclasses of this class. 407 Klass* super = ((InstanceKlass*)cie->klass())->java_super(); 408 while (super != NULL) { 409 KlassInfoEntry* super_cie = cit->lookup(super); 410 super_cie->set_do_print(true); 411 super = super->super(); 412 } 413 414 // Set do_print for this class and all of its subclasses. 415 Stack <KlassInfoEntry*, mtClass> class_stack; 416 class_stack.push(cie); 417 while (!class_stack.is_empty()) { 418 KlassInfoEntry* curr_cie = class_stack.pop(); 419 curr_cie->set_do_print(true); 420 if (print_subclasses && curr_cie->subclasses() != NULL) { 421 // Current class has subclasses, so push all of them onto the stack. 422 for (int i = 0; i < curr_cie->subclasses()->length(); i++) { 423 KlassInfoEntry* cie = curr_cie->subclasses()->at(i); 424 class_stack.push(cie); 425 } 426 } 427 } 428 } 429 430 static void print_indent(outputStream* st, int indent) { 431 while (indent != 0) { 432 st->print("|"); 433 indent--; 434 if (indent != 0) { 435 st->print(" "); 436 } 437 } 438 } 439 440 // Print the class name and its unique ClassLoader identifer. 441 static void print_classname(outputStream* st, Klass* klass) { 442 oop loader_oop = klass->class_loader_data()->class_loader(); 443 st->print("%s/", klass->external_name()); 444 if (loader_oop == NULL) { 445 st->print("null"); 446 } else { 447 st->print(INTPTR_FORMAT, p2i(klass->class_loader_data())); 448 } 449 } 450 451 static void print_interface(outputStream* st, InstanceKlass* intf_klass, const char* intf_type, int indent) { 452 print_indent(st, indent); 453 st->print(" implements "); 454 print_classname(st, intf_klass); 455 st->print(" (%s intf)\n", intf_type); 456 } 457 458 void KlassHierarchy::print_class(outputStream* st, KlassInfoEntry* cie, bool print_interfaces) { 459 ResourceMark rm; 460 InstanceKlass* klass = (InstanceKlass*)cie->klass(); 461 int indent = 0; 462 463 // Print indentation with proper indicators of superclass. 464 Klass* super = klass->super(); 465 while (super != NULL) { 466 super = super->super(); 467 indent++; 468 } 469 print_indent(st, indent); 470 if (indent != 0) st->print("--"); 471 472 // Print the class name, its unique ClassLoader identifer, and if it is an interface. 473 print_classname(st, klass); 474 if (klass->is_interface()) { 475 st->print(" (intf)"); 476 } 477 // Special treatment for generated core reflection accessor classes: print invocation target. 478 if (ReflectionAccessorImplKlassHelper::is_generated_accessor(klass)) { 479 st->print(" (invokes: "); 480 ReflectionAccessorImplKlassHelper::print_invocation_target(st, klass); 481 st->print(")"); 482 } 483 st->print("\n"); 484 485 // Print any interfaces the class has. 486 if (print_interfaces) { 487 Array<InstanceKlass*>* local_intfs = klass->local_interfaces(); 488 Array<InstanceKlass*>* trans_intfs = klass->transitive_interfaces(); 489 for (int i = 0; i < local_intfs->length(); i++) { 490 print_interface(st, local_intfs->at(i), "declared", indent); 491 } 492 for (int i = 0; i < trans_intfs->length(); i++) { 493 InstanceKlass* trans_interface = trans_intfs->at(i); 494 // Only print transitive interfaces if they are not also declared. 495 if (!local_intfs->contains(trans_interface)) { 496 print_interface(st, trans_interface, "inherited", indent); 497 } 498 } 499 } 500 } 501 502 void KlassInfoHisto::print_histo_on(outputStream* st) { 503 st->print_cr(" num #instances #bytes class name (module)"); 504 st->print_cr("-------------------------------------------------------"); 505 print_elements(st); 506 } 507 508 class HistoClosure : public KlassInfoClosure { 509 private: 510 KlassInfoHisto* _cih; 511 public: 512 HistoClosure(KlassInfoHisto* cih) : _cih(cih) {} 513 514 void do_cinfo(KlassInfoEntry* cie) { 515 _cih->add(cie); 516 } 517 }; 518 519 class RecordInstanceClosure : public ObjectClosure { 520 private: 521 KlassInfoTable* _cit; 522 size_t _missed_count; 523 BoolObjectClosure* _filter; 524 public: 525 RecordInstanceClosure(KlassInfoTable* cit, BoolObjectClosure* filter) : 526 _cit(cit), _missed_count(0), _filter(filter) {} 527 528 void do_object(oop obj) { 529 if (should_visit(obj)) { 530 if (!_cit->record_instance(obj)) { 531 _missed_count++; 532 } 533 } 534 } 535 536 size_t missed_count() { return _missed_count; } 537 538 private: 539 bool should_visit(oop obj) { 540 return _filter == NULL || _filter->do_object_b(obj); 541 } 542 }; 543 544 // Heap inspection for every worker. 545 // When native OOM hanppens for KlassInfoTable, set _success to false. 546 void ParHeapInspectTask::work(uint worker_id) { 547 size_t missed_count = 0; 548 bool merge_success = true; 549 if (!Atomic::load(&_success)) { 550 // other worker has failed on parallel iteration. 551 return; 552 } 553 554 KlassInfoTable cit(false); 555 if (!cit.allocation_failed()) { 556 RecordInstanceClosure ric(&cit, _filter); 557 _poi->object_iterate(&ric, worker_id); 558 missed_count = ric.missed_count(); 559 } else { 560 // fail to allocate memory, stop parallel mode 561 Atomic::store(&_success, false); 562 return; 563 } 564 { 565 MutexLocker x(&_mutex); 566 merge_success = _shared_cit->merge(&cit); 567 } 568 if (!merge_success) { 569 Atomic::store(&_success, false); 570 return; 571 } 572 Atomic::add(&_shared_missed_count, missed_count); 573 } 574 575 size_t HeapInspection::populate_table(KlassInfoTable* cit, BoolObjectClosure *filter, size_t parallel_thread_num) { 576 ResourceMark rm; 577 578 // Try parallel first. 579 if (parallel_thread_num > 1) { 580 ParallelObjectIterator* poi = Universe::heap()->parallel_object_iterator(parallel_thread_num); 581 if (poi != NULL) { 582 ParHeapInspectTask task(poi, cit, filter); 583 Universe::heap()->run_task(&task); 584 delete poi; 585 if (task.success()) { 586 return task.missed_count(); 587 } 588 } 589 } 590 591 // If no parallel iteration available, run serially. 592 RecordInstanceClosure ric(cit, filter); 593 Universe::heap()->object_iterate(&ric); 594 return ric.missed_count(); 595 } 596 597 void HeapInspection::heap_inspection(outputStream* st, size_t parallel_thread_num) { 598 ResourceMark rm; 599 600 KlassInfoTable cit(false); 601 if (!cit.allocation_failed()) { 602 size_t missed_count = 0;; 603 // populate table with object allocation info 604 missed_count = populate_table(&cit, NULL, parallel_thread_num); 605 if (missed_count != 0) { 606 log_info(gc, classhisto)("WARNING: Ran out of C-heap; undercounted " SIZE_FORMAT 607 " total instances in data below", 608 missed_count); 609 } 610 611 // Sort and print klass instance info 612 KlassInfoHisto histo(&cit); 613 HistoClosure hc(&histo); 614 615 cit.iterate(&hc); 616 617 histo.sort(); 618 histo.print_histo_on(st); 619 } else { 620 st->print_cr("ERROR: Ran out of C-heap; histogram not generated"); 621 } 622 st->flush(); 623 } 624 625 class FindInstanceClosure : public ObjectClosure { 626 private: 627 Klass* _klass; 628 GrowableArray<oop>* _result; 629 630 public: 631 FindInstanceClosure(Klass* k, GrowableArray<oop>* result) : _klass(k), _result(result) {}; 632 633 void do_object(oop obj) { 634 if (obj->is_a(_klass)) { 635 // obj was read with AS_NO_KEEPALIVE, or equivalent. 636 // The object needs to be kept alive when it is published. 637 Universe::heap()->keep_alive(obj); 638 639 _result->append(obj); 640 } 641 } 642 }; 643 644 void HeapInspection::find_instances_at_safepoint(Klass* k, GrowableArray<oop>* result) { 645 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); 646 assert(Heap_lock->is_locked(), "should have the Heap_lock"); 647 648 // Ensure that the heap is parsable 649 Universe::heap()->ensure_parsability(false); // no need to retire TALBs 650 651 // Iterate over objects in the heap 652 FindInstanceClosure fic(k, result); 653 Universe::heap()->object_iterate(&fic); 654 }