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%s)", 105 (int64_t)_instance_count, 106 (uint64_t)_instance_words * HeapWordSize, 107 name(), 108 module->name()->as_C_string(), 109 module->version() != NULL ? "@" : "", 110 module->version() != NULL ? module->version()->as_C_string() : ""); 111 } else { 112 st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s", 113 (int64_t)_instance_count, 114 (uint64_t)_instance_words * HeapWordSize, 115 name()); 116 } 117 } 118 119 KlassInfoEntry* KlassInfoBucket::lookup(Klass* const k) { 120 // Can happen if k is an archived class that we haven't loaded yet. 121 if (k->java_mirror_no_keepalive() == NULL) { 122 return NULL; 123 } 124 125 KlassInfoEntry* elt = _list; 126 while (elt != NULL) { 127 if (elt->is_equal(k)) { 128 return elt; 129 } 130 elt = elt->next(); 131 } 132 elt = new (std::nothrow) KlassInfoEntry(k, list()); 133 // We may be out of space to allocate the new entry. 134 if (elt != NULL) { 135 set_list(elt); 136 } 137 return elt; 138 } 139 140 void KlassInfoBucket::iterate(KlassInfoClosure* cic) { 141 KlassInfoEntry* elt = _list; 142 while (elt != NULL) { 143 cic->do_cinfo(elt); 144 elt = elt->next(); 145 } 146 } 147 148 void KlassInfoBucket::empty() { 149 KlassInfoEntry* elt = _list; 150 _list = NULL; 151 while (elt != NULL) { 152 KlassInfoEntry* next = elt->next(); 153 delete elt; 154 elt = next; 155 } 156 } 157 158 class KlassInfoTable::AllClassesFinder : public LockedClassesDo { 159 KlassInfoTable *_table; 160 public: 161 AllClassesFinder(KlassInfoTable* table) : _table(table) {} 162 virtual void do_klass(Klass* k) { 163 // This has the SIDE EFFECT of creating a KlassInfoEntry 164 // for <k>, if one doesn't exist yet. 165 _table->lookup(k); 166 } 167 }; 168 169 170 KlassInfoTable::KlassInfoTable(bool add_all_classes) { 171 _size_of_instances_in_words = 0; 172 _ref = (HeapWord*) Universe::boolArrayKlassObj(); 173 _buckets = 174 (KlassInfoBucket*) AllocateHeap(sizeof(KlassInfoBucket) * _num_buckets, 175 mtInternal, CURRENT_PC, AllocFailStrategy::RETURN_NULL); 176 if (_buckets != NULL) { 177 for (int index = 0; index < _num_buckets; index++) { 178 _buckets[index].initialize(); 179 } 180 if (add_all_classes) { 181 AllClassesFinder finder(this); 182 ClassLoaderDataGraph::classes_do(&finder); 183 } 184 } 185 } 186 187 KlassInfoTable::~KlassInfoTable() { 188 if (_buckets != NULL) { 189 for (int index = 0; index < _num_buckets; index++) { 190 _buckets[index].empty(); 191 } 192 FREE_C_HEAP_ARRAY(KlassInfoBucket, _buckets); 193 _buckets = NULL; 194 } 195 } 196 197 uint KlassInfoTable::hash(const Klass* p) { 198 return (uint)(((uintptr_t)p - (uintptr_t)_ref) >> 2); 199 } 200 201 KlassInfoEntry* KlassInfoTable::lookup(Klass* k) { 202 uint idx = hash(k) % _num_buckets; 203 assert(_buckets != NULL, "Allocation failure should have been caught"); 204 KlassInfoEntry* e = _buckets[idx].lookup(k); 205 // Lookup may fail if this is a new klass for which we 206 // could not allocate space for an new entry, or if it's 207 // an archived class that we haven't loaded yet. 208 assert(e == NULL || k == e->klass(), "must be equal"); 209 return e; 210 } 211 212 // Return false if the entry could not be recorded on account 213 // of running out of space required to create a new entry. 214 bool KlassInfoTable::record_instance(const oop obj) { 215 Klass* k = obj->klass(); 216 KlassInfoEntry* elt = lookup(k); 217 // elt may be NULL if it's a new klass for which we 218 // could not allocate space for a new entry in the hashtable. 219 if (elt != NULL) { 220 elt->set_count(elt->count() + 1); 221 elt->set_words(elt->words() + obj->size()); 222 _size_of_instances_in_words += obj->size(); 223 return true; 224 } else { 225 return false; 226 } 227 } 228 229 void KlassInfoTable::iterate(KlassInfoClosure* cic) { 230 assert(_buckets != NULL, "Allocation failure should have been caught"); 231 for (int index = 0; index < _num_buckets; index++) { 232 _buckets[index].iterate(cic); 233 } 234 } 235 236 size_t KlassInfoTable::size_of_instances_in_words() const { 237 return _size_of_instances_in_words; 238 } 239 240 int KlassInfoHisto::sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2) { 241 return (*e1)->compare(*e1,*e2); 242 } 243 244 KlassInfoHisto::KlassInfoHisto(KlassInfoTable* cit) : 245 _cit(cit) { 246 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<KlassInfoEntry*>(_histo_initial_size, true); 247 } 248 249 KlassInfoHisto::~KlassInfoHisto() { 250 delete _elements; 251 } 252 253 void KlassInfoHisto::add(KlassInfoEntry* cie) { 254 elements()->append(cie); 255 } 256 257 void KlassInfoHisto::sort() { 258 elements()->sort(KlassInfoHisto::sort_helper); 259 } 260 261 void KlassInfoHisto::print_elements(outputStream* st) const { 262 // simplify the formatting (ILP32 vs LP64) - store the sum in 64-bit 263 int64_t total = 0; 264 uint64_t totalw = 0; 265 for(int i=0; i < elements()->length(); i++) { 266 st->print("%4d: ", i+1); 267 elements()->at(i)->print_on(st); 268 total += elements()->at(i)->count(); 269 totalw += elements()->at(i)->words(); 270 } 271 st->print_cr("Total " INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13), 272 total, totalw * HeapWordSize); 273 } 274 275 class HierarchyClosure : public KlassInfoClosure { 276 private: 277 GrowableArray<KlassInfoEntry*> *_elements; 278 public: 279 HierarchyClosure(GrowableArray<KlassInfoEntry*> *_elements) : _elements(_elements) {} 280 281 void do_cinfo(KlassInfoEntry* cie) { 282 // ignore array classes 283 if (cie->klass()->is_instance_klass()) { 284 _elements->append(cie); 285 } 286 } 287 }; 288 289 void KlassHierarchy::print_class_hierarchy(outputStream* st, bool print_interfaces, 290 bool print_subclasses, char* classname) { 291 ResourceMark rm; 292 Stack <KlassInfoEntry*, mtClass> class_stack; 293 GrowableArray<KlassInfoEntry*> elements; 294 295 // Add all classes to the KlassInfoTable, which allows for quick lookup. 296 // A KlassInfoEntry will be created for each class. 297 KlassInfoTable cit(true); 298 if (cit.allocation_failed()) { 299 st->print_cr("ERROR: Ran out of C-heap; hierarchy not generated"); 300 return; 301 } 302 303 // Add all created KlassInfoEntry instances to the elements array for easy 304 // iteration, and to allow each KlassInfoEntry instance to have a unique index. 305 HierarchyClosure hc(&elements); 306 cit.iterate(&hc); 307 308 for(int i = 0; i < elements.length(); i++) { 309 KlassInfoEntry* cie = elements.at(i); 310 Klass* super = cie->klass()->super(); 311 312 // Set the index for the class. 313 cie->set_index(i + 1); 314 315 // Add the class to the subclass array of its superclass. 316 if (super != NULL) { 317 KlassInfoEntry* super_cie = cit.lookup(super); 318 assert(super_cie != NULL, "could not lookup superclass"); 319 super_cie->add_subclass(cie); 320 } 321 } 322 323 // Set the do_print flag for each class that should be printed. 324 for(int i = 0; i < elements.length(); i++) { 325 KlassInfoEntry* cie = elements.at(i); 326 if (classname == NULL) { 327 // We are printing all classes. 328 cie->set_do_print(true); 329 } else { 330 // We are only printing the hierarchy of a specific class. 331 if (strcmp(classname, cie->klass()->external_name()) == 0) { 332 KlassHierarchy::set_do_print_for_class_hierarchy(cie, &cit, print_subclasses); 333 } 334 } 335 } 336 337 // Now we do a depth first traversal of the class hierachry. The class_stack will 338 // maintain the list of classes we still need to process. Start things off 339 // by priming it with java.lang.Object. 340 KlassInfoEntry* jlo_cie = cit.lookup(SystemDictionary::Object_klass()); 341 assert(jlo_cie != NULL, "could not lookup java.lang.Object"); 342 class_stack.push(jlo_cie); 343 344 // Repeatedly pop the top item off the stack, print its class info, 345 // and push all of its subclasses on to the stack. Do this until there 346 // are no classes left on the stack. 347 while (!class_stack.is_empty()) { 348 KlassInfoEntry* curr_cie = class_stack.pop(); 349 if (curr_cie->do_print()) { 350 print_class(st, curr_cie, print_interfaces); 351 if (curr_cie->subclasses() != NULL) { 352 // Current class has subclasses, so push all of them onto the stack. 353 for (int i = 0; i < curr_cie->subclasses()->length(); i++) { 354 KlassInfoEntry* cie = curr_cie->subclasses()->at(i); 355 if (cie->do_print()) { 356 class_stack.push(cie); 357 } 358 } 359 } 360 } 361 } 362 363 st->flush(); 364 } 365 366 // Sets the do_print flag for every superclass and subclass of the specified class. 367 void KlassHierarchy::set_do_print_for_class_hierarchy(KlassInfoEntry* cie, KlassInfoTable* cit, 368 bool print_subclasses) { 369 // Set do_print for all superclasses of this class. 370 Klass* super = ((InstanceKlass*)cie->klass())->java_super(); 371 while (super != NULL) { 372 KlassInfoEntry* super_cie = cit->lookup(super); 373 super_cie->set_do_print(true); 374 super = super->super(); 375 } 376 377 // Set do_print for this class and all of its subclasses. 378 Stack <KlassInfoEntry*, mtClass> class_stack; 379 class_stack.push(cie); 380 while (!class_stack.is_empty()) { 381 KlassInfoEntry* curr_cie = class_stack.pop(); 382 curr_cie->set_do_print(true); 383 if (print_subclasses && curr_cie->subclasses() != NULL) { 384 // Current class has subclasses, so push all of them onto the stack. 385 for (int i = 0; i < curr_cie->subclasses()->length(); i++) { 386 KlassInfoEntry* cie = curr_cie->subclasses()->at(i); 387 class_stack.push(cie); 388 } 389 } 390 } 391 } 392 393 static void print_indent(outputStream* st, int indent) { 394 while (indent != 0) { 395 st->print("|"); 396 indent--; 397 if (indent != 0) { 398 st->print(" "); 399 } 400 } 401 } 402 403 // Print the class name and its unique ClassLoader identifer. 404 static void print_classname(outputStream* st, Klass* klass) { 405 oop loader_oop = klass->class_loader_data()->class_loader(); 406 st->print("%s/", klass->external_name()); 407 if (loader_oop == NULL) { 408 st->print("null"); 409 } else { 410 st->print(INTPTR_FORMAT, p2i(klass->class_loader_data())); 411 } 412 } 413 414 static void print_interface(outputStream* st, InstanceKlass* intf_klass, const char* intf_type, int indent) { 415 print_indent(st, indent); 416 st->print(" implements "); 417 print_classname(st, intf_klass); 418 st->print(" (%s intf)\n", intf_type); 419 } 420 421 void KlassHierarchy::print_class(outputStream* st, KlassInfoEntry* cie, bool print_interfaces) { 422 ResourceMark rm; 423 InstanceKlass* klass = (InstanceKlass*)cie->klass(); 424 int indent = 0; 425 426 // Print indentation with proper indicators of superclass. 427 Klass* super = klass->super(); 428 while (super != NULL) { 429 super = super->super(); 430 indent++; 431 } 432 print_indent(st, indent); 433 if (indent != 0) st->print("--"); 434 435 // Print the class name, its unique ClassLoader identifer, and if it is an interface. 436 print_classname(st, klass); 437 if (klass->is_interface()) { 438 st->print(" (intf)"); 439 } 440 // Special treatment for generated core reflection accessor classes: print invocation target. 441 if (ReflectionAccessorImplKlassHelper::is_generated_accessor(klass)) { 442 st->print(" (invokes: "); 443 ReflectionAccessorImplKlassHelper::print_invocation_target(st, klass); 444 st->print(")"); 445 } 446 st->print("\n"); 447 448 // Print any interfaces the class has. 449 if (print_interfaces) { 450 Array<InstanceKlass*>* local_intfs = klass->local_interfaces(); 451 Array<InstanceKlass*>* trans_intfs = klass->transitive_interfaces(); 452 for (int i = 0; i < local_intfs->length(); i++) { 453 print_interface(st, local_intfs->at(i), "declared", indent); 454 } 455 for (int i = 0; i < trans_intfs->length(); i++) { 456 InstanceKlass* trans_interface = trans_intfs->at(i); 457 // Only print transitive interfaces if they are not also declared. 458 if (!local_intfs->contains(trans_interface)) { 459 print_interface(st, trans_interface, "inherited", indent); 460 } 461 } 462 } 463 } 464 465 void KlassInfoHisto::print_histo_on(outputStream* st) { 466 st->print_cr(" num #instances #bytes class name (module)"); 467 st->print_cr("-------------------------------------------------------"); 468 print_elements(st); 469 } 470 471 class HistoClosure : public KlassInfoClosure { 472 private: 473 KlassInfoHisto* _cih; 474 public: 475 HistoClosure(KlassInfoHisto* cih) : _cih(cih) {} 476 477 void do_cinfo(KlassInfoEntry* cie) { 478 _cih->add(cie); 479 } 480 }; 481 482 class RecordInstanceClosure : public ObjectClosure { 483 private: 484 KlassInfoTable* _cit; 485 size_t _missed_count; 486 BoolObjectClosure* _filter; 487 public: 488 RecordInstanceClosure(KlassInfoTable* cit, BoolObjectClosure* filter) : 489 _cit(cit), _missed_count(0), _filter(filter) {} 490 491 void do_object(oop obj) { 492 if (should_visit(obj)) { 493 if (!_cit->record_instance(obj)) { 494 _missed_count++; 495 } 496 } 497 } 498 499 size_t missed_count() { return _missed_count; } 500 501 private: 502 bool should_visit(oop obj) { 503 return _filter == NULL || _filter->do_object_b(obj); 504 } 505 }; 506 507 size_t HeapInspection::populate_table(KlassInfoTable* cit, BoolObjectClosure *filter) { 508 ResourceMark rm; 509 510 RecordInstanceClosure ric(cit, filter); 511 Universe::heap()->object_iterate(&ric); 512 return ric.missed_count(); 513 } 514 515 void HeapInspection::heap_inspection(outputStream* st) { 516 ResourceMark rm; 517 518 KlassInfoTable cit(false); 519 if (!cit.allocation_failed()) { 520 // populate table with object allocation info 521 size_t missed_count = populate_table(&cit); 522 if (missed_count != 0) { 523 log_info(gc, classhisto)("WARNING: Ran out of C-heap; undercounted " SIZE_FORMAT 524 " total instances in data below", 525 missed_count); 526 } 527 528 // Sort and print klass instance info 529 KlassInfoHisto histo(&cit); 530 HistoClosure hc(&histo); 531 532 cit.iterate(&hc); 533 534 histo.sort(); 535 histo.print_histo_on(st); 536 } else { 537 st->print_cr("ERROR: Ran out of C-heap; histogram not generated"); 538 } 539 st->flush(); 540 } 541 542 class FindInstanceClosure : public ObjectClosure { 543 private: 544 Klass* _klass; 545 GrowableArray<oop>* _result; 546 547 public: 548 FindInstanceClosure(Klass* k, GrowableArray<oop>* result) : _klass(k), _result(result) {}; 549 550 void do_object(oop obj) { 551 if (obj->is_a(_klass)) { 552 // obj was read with AS_NO_KEEPALIVE, or equivalent. 553 // The object needs to be kept alive when it is published. 554 Universe::heap()->keep_alive(obj); 555 556 _result->append(obj); 557 } 558 } 559 }; 560 561 void HeapInspection::find_instances_at_safepoint(Klass* k, GrowableArray<oop>* result) { 562 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); 563 assert(Heap_lock->is_locked(), "should have the Heap_lock"); 564 565 // Ensure that the heap is parsable 566 Universe::heap()->ensure_parsability(false); // no need to retire TALBs 567 568 // Iterate over objects in the heap 569 FindInstanceClosure fic(k, result); 570 Universe::heap()->object_iterate(&fic); 571 }