1 /* 2 * Copyright (c) 2001, 2019, 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 "code/nmethod.hpp" 27 #include "gc/g1/g1BlockOffsetTable.inline.hpp" 28 #include "gc/g1/g1CollectedHeap.inline.hpp" 29 #include "gc/g1/g1CollectionSet.hpp" 30 #include "gc/g1/g1HeapRegionTraceType.hpp" 31 #include "gc/g1/g1NUMA.hpp" 32 #include "gc/g1/g1OopClosures.inline.hpp" 33 #include "gc/g1/heapRegion.inline.hpp" 34 #include "gc/g1/heapRegionBounds.inline.hpp" 35 #include "gc/g1/heapRegionManager.inline.hpp" 36 #include "gc/g1/heapRegionRemSet.hpp" 37 #include "gc/g1/heapRegionTracer.hpp" 38 #include "gc/shared/genOopClosures.inline.hpp" 39 #include "logging/log.hpp" 40 #include "logging/logStream.hpp" 41 #include "memory/iterator.inline.hpp" 42 #include "memory/resourceArea.hpp" 43 #include "oops/access.inline.hpp" 44 #include "oops/compressedOops.inline.hpp" 45 #include "oops/oop.inline.hpp" 46 #include "runtime/atomic.hpp" 47 #include "runtime/orderAccess.hpp" 48 49 int HeapRegion::LogOfHRGrainBytes = 0; 50 int HeapRegion::LogOfHRGrainWords = 0; 51 int HeapRegion::LogCardsPerRegion = 0; 52 size_t HeapRegion::GrainBytes = 0; 53 size_t HeapRegion::GrainWords = 0; 54 size_t HeapRegion::CardsPerRegion = 0; 55 56 size_t HeapRegion::max_region_size() { 57 return HeapRegionBounds::max_size(); 58 } 59 60 size_t HeapRegion::min_region_size_in_words() { 61 return HeapRegionBounds::min_size() >> LogHeapWordSize; 62 } 63 64 void HeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) { 65 size_t region_size = G1HeapRegionSize; 66 if (FLAG_IS_DEFAULT(G1HeapRegionSize)) { 67 size_t average_heap_size = (initial_heap_size + max_heap_size) / 2; 68 region_size = MAX2(average_heap_size / HeapRegionBounds::target_number(), 69 HeapRegionBounds::min_size()); 70 } 71 72 int region_size_log = log2_long((jlong) region_size); 73 // Recalculate the region size to make sure it's a power of 74 // 2. This means that region_size is the largest power of 2 that's 75 // <= what we've calculated so far. 76 region_size = ((size_t)1 << region_size_log); 77 78 // Now make sure that we don't go over or under our limits. 79 if (region_size < HeapRegionBounds::min_size()) { 80 region_size = HeapRegionBounds::min_size(); 81 } else if (region_size > HeapRegionBounds::max_size()) { 82 region_size = HeapRegionBounds::max_size(); 83 } 84 85 // And recalculate the log. 86 region_size_log = log2_long((jlong) region_size); 87 88 // Now, set up the globals. 89 guarantee(LogOfHRGrainBytes == 0, "we should only set it once"); 90 LogOfHRGrainBytes = region_size_log; 91 92 guarantee(LogOfHRGrainWords == 0, "we should only set it once"); 93 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize; 94 95 guarantee(GrainBytes == 0, "we should only set it once"); 96 // The cast to int is safe, given that we've bounded region_size by 97 // MIN_REGION_SIZE and MAX_REGION_SIZE. 98 GrainBytes = region_size; 99 log_info(gc, heap)("Heap region size: " SIZE_FORMAT "M", GrainBytes / M); 100 101 guarantee(GrainWords == 0, "we should only set it once"); 102 GrainWords = GrainBytes >> LogHeapWordSize; 103 guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity"); 104 105 guarantee(CardsPerRegion == 0, "we should only set it once"); 106 CardsPerRegion = GrainBytes >> G1CardTable::card_shift; 107 108 LogCardsPerRegion = log2_long((jlong) CardsPerRegion); 109 110 if (G1HeapRegionSize != GrainBytes) { 111 FLAG_SET_ERGO(G1HeapRegionSize, GrainBytes); 112 } 113 } 114 115 void HeapRegion::hr_clear(bool keep_remset, bool clear_space, bool locked) { 116 assert(_humongous_start_region == NULL, 117 "we should have already filtered out humongous regions"); 118 assert(!in_collection_set(), 119 "Should not clear heap region %u in the collection set", hrm_index()); 120 121 clear_young_index_in_cset(); 122 clear_index_in_opt_cset(); 123 uninstall_surv_rate_group(); 124 set_free(); 125 reset_pre_dummy_top(); 126 127 if (!keep_remset) { 128 if (locked) { 129 rem_set()->clear_locked(); 130 } else { 131 rem_set()->clear(); 132 } 133 } 134 135 zero_marked_bytes(); 136 137 init_top_at_mark_start(); 138 if (clear_space) clear(SpaceDecorator::Mangle); 139 140 _evacuation_failed = false; 141 _gc_efficiency = 0.0; 142 _recorded_rs_length = 0; 143 _predicted_elapsed_time_ms = 0.0; 144 } 145 146 void HeapRegion::clear_cardtable() { 147 G1CardTable* ct = G1CollectedHeap::heap()->card_table(); 148 ct->clear(MemRegion(bottom(), end())); 149 } 150 151 void HeapRegion::calc_gc_efficiency() { 152 // GC efficiency is the ratio of how much space would be 153 // reclaimed over how long we predict it would take to reclaim it. 154 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 155 G1Policy* policy = g1h->policy(); 156 157 // Retrieve a prediction of the elapsed time for this region for 158 // a mixed gc because the region will only be evacuated during a 159 // mixed gc. 160 double region_elapsed_time_ms = 161 policy->predict_region_elapsed_time_ms(this, false /* for_young_gc */); 162 _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms; 163 } 164 165 void HeapRegion::set_free() { 166 report_region_type_change(G1HeapRegionTraceType::Free); 167 _type.set_free(); 168 } 169 170 void HeapRegion::set_eden() { 171 report_region_type_change(G1HeapRegionTraceType::Eden); 172 _type.set_eden(); 173 } 174 175 void HeapRegion::set_eden_pre_gc() { 176 report_region_type_change(G1HeapRegionTraceType::Eden); 177 _type.set_eden_pre_gc(); 178 } 179 180 void HeapRegion::set_survivor() { 181 report_region_type_change(G1HeapRegionTraceType::Survivor); 182 _type.set_survivor(); 183 } 184 185 void HeapRegion::move_to_old() { 186 if (_type.relabel_as_old()) { 187 report_region_type_change(G1HeapRegionTraceType::Old); 188 } 189 } 190 191 void HeapRegion::set_old() { 192 report_region_type_change(G1HeapRegionTraceType::Old); 193 _type.set_old(); 194 } 195 196 void HeapRegion::set_open_archive() { 197 report_region_type_change(G1HeapRegionTraceType::OpenArchive); 198 _type.set_open_archive(); 199 } 200 201 void HeapRegion::set_closed_archive() { 202 report_region_type_change(G1HeapRegionTraceType::ClosedArchive); 203 _type.set_closed_archive(); 204 } 205 206 void HeapRegion::set_starts_humongous(HeapWord* obj_top, size_t fill_size) { 207 assert(!is_humongous(), "sanity / pre-condition"); 208 assert(top() == bottom(), "should be empty"); 209 210 report_region_type_change(G1HeapRegionTraceType::StartsHumongous); 211 _type.set_starts_humongous(); 212 _humongous_start_region = this; 213 214 _bot_part.set_for_starts_humongous(obj_top, fill_size); 215 } 216 217 void HeapRegion::set_continues_humongous(HeapRegion* first_hr) { 218 assert(!is_humongous(), "sanity / pre-condition"); 219 assert(top() == bottom(), "should be empty"); 220 assert(first_hr->is_starts_humongous(), "pre-condition"); 221 222 report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous); 223 _type.set_continues_humongous(); 224 _humongous_start_region = first_hr; 225 226 _bot_part.set_object_can_span(true); 227 } 228 229 void HeapRegion::clear_humongous() { 230 assert(is_humongous(), "pre-condition"); 231 232 assert(capacity() == HeapRegion::GrainBytes, "pre-condition"); 233 _humongous_start_region = NULL; 234 235 _bot_part.set_object_can_span(false); 236 } 237 238 HeapRegion::HeapRegion(uint hrm_index, 239 G1BlockOffsetTable* bot, 240 MemRegion mr) : 241 _bottom(mr.start()), 242 _end(mr.end()), 243 _top(NULL), 244 _compaction_top(NULL), 245 _bot_part(bot, this), 246 _par_alloc_lock(Mutex::leaf, "HeapRegion par alloc lock", true), 247 _pre_dummy_top(NULL), 248 _rem_set(NULL), 249 _hrm_index(hrm_index), 250 _type(), 251 _humongous_start_region(NULL), 252 _evacuation_failed(false), 253 _index_in_opt_cset(InvalidCSetIndex), 254 _next(NULL), _prev(NULL), 255 #ifdef ASSERT 256 _containing_set(NULL), 257 #endif 258 _prev_top_at_mark_start(NULL), _next_top_at_mark_start(NULL), 259 _prev_marked_bytes(0), _next_marked_bytes(0), 260 _young_index_in_cset(-1), 261 _surv_rate_group(NULL), _age_index(-1), _gc_efficiency(0.0), 262 _recorded_rs_length(0), _predicted_elapsed_time_ms(0), 263 _node_index(G1NUMA::UnknownNodeIndex) 264 { 265 assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()), 266 "invalid space boundaries"); 267 268 _rem_set = new HeapRegionRemSet(bot, this); 269 initialize(); 270 } 271 272 void HeapRegion::initialize(bool clear_space, bool mangle_space) { 273 assert(_rem_set->is_empty(), "Remembered set must be empty"); 274 275 if (clear_space) { 276 clear(mangle_space); 277 } 278 279 set_top(bottom()); 280 set_compaction_top(bottom()); 281 reset_bot(); 282 283 hr_clear(false /*par*/, false /*clear_space*/); 284 } 285 286 void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) { 287 HeapRegionTracer::send_region_type_change(_hrm_index, 288 get_trace_type(), 289 to, 290 (uintptr_t)bottom(), 291 used()); 292 } 293 294 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark, 295 bool during_conc_mark) { 296 // We always recreate the prev marking info and we'll explicitly 297 // mark all objects we find to be self-forwarded on the prev 298 // bitmap. So all objects need to be below PTAMS. 299 _prev_marked_bytes = 0; 300 301 if (during_initial_mark) { 302 // During initial-mark, we'll also explicitly mark all objects 303 // we find to be self-forwarded on the next bitmap. So all 304 // objects need to be below NTAMS. 305 _next_top_at_mark_start = top(); 306 _next_marked_bytes = 0; 307 } else if (during_conc_mark) { 308 // During concurrent mark, all objects in the CSet (including 309 // the ones we find to be self-forwarded) are implicitly live. 310 // So all objects need to be above NTAMS. 311 _next_top_at_mark_start = bottom(); 312 _next_marked_bytes = 0; 313 } 314 } 315 316 void HeapRegion::note_self_forwarding_removal_end(size_t marked_bytes) { 317 assert(marked_bytes <= used(), 318 "marked: " SIZE_FORMAT " used: " SIZE_FORMAT, marked_bytes, used()); 319 _prev_top_at_mark_start = top(); 320 _prev_marked_bytes = marked_bytes; 321 } 322 323 // Code roots support 324 325 void HeapRegion::add_strong_code_root(nmethod* nm) { 326 HeapRegionRemSet* hrrs = rem_set(); 327 hrrs->add_strong_code_root(nm); 328 } 329 330 void HeapRegion::add_strong_code_root_locked(nmethod* nm) { 331 assert_locked_or_safepoint(CodeCache_lock); 332 HeapRegionRemSet* hrrs = rem_set(); 333 hrrs->add_strong_code_root_locked(nm); 334 } 335 336 void HeapRegion::remove_strong_code_root(nmethod* nm) { 337 HeapRegionRemSet* hrrs = rem_set(); 338 hrrs->remove_strong_code_root(nm); 339 } 340 341 void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const { 342 HeapRegionRemSet* hrrs = rem_set(); 343 hrrs->strong_code_roots_do(blk); 344 } 345 346 class VerifyStrongCodeRootOopClosure: public OopClosure { 347 const HeapRegion* _hr; 348 bool _failures; 349 bool _has_oops_in_region; 350 351 template <class T> void do_oop_work(T* p) { 352 T heap_oop = RawAccess<>::oop_load(p); 353 if (!CompressedOops::is_null(heap_oop)) { 354 oop obj = CompressedOops::decode_not_null(heap_oop); 355 356 // Note: not all the oops embedded in the nmethod are in the 357 // current region. We only look at those which are. 358 if (_hr->is_in(obj)) { 359 // Object is in the region. Check that its less than top 360 if (_hr->top() <= (HeapWord*)obj) { 361 // Object is above top 362 log_error(gc, verify)("Object " PTR_FORMAT " in region " HR_FORMAT " is above top ", 363 p2i(obj), HR_FORMAT_PARAMS(_hr)); 364 _failures = true; 365 return; 366 } 367 // Nmethod has at least one oop in the current region 368 _has_oops_in_region = true; 369 } 370 } 371 } 372 373 public: 374 VerifyStrongCodeRootOopClosure(const HeapRegion* hr): 375 _hr(hr), _failures(false), _has_oops_in_region(false) {} 376 377 void do_oop(narrowOop* p) { do_oop_work(p); } 378 void do_oop(oop* p) { do_oop_work(p); } 379 380 bool failures() { return _failures; } 381 bool has_oops_in_region() { return _has_oops_in_region; } 382 }; 383 384 class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure { 385 const HeapRegion* _hr; 386 bool _failures; 387 public: 388 VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) : 389 _hr(hr), _failures(false) {} 390 391 void do_code_blob(CodeBlob* cb) { 392 nmethod* nm = (cb == NULL) ? NULL : cb->as_compiled_method()->as_nmethod_or_null(); 393 if (nm != NULL) { 394 // Verify that the nemthod is live 395 if (!nm->is_alive()) { 396 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has dead nmethod " PTR_FORMAT " in its strong code roots", 397 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm)); 398 _failures = true; 399 } else { 400 VerifyStrongCodeRootOopClosure oop_cl(_hr); 401 nm->oops_do(&oop_cl); 402 if (!oop_cl.has_oops_in_region()) { 403 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has nmethod " PTR_FORMAT " in its strong code roots with no pointers into region", 404 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm)); 405 _failures = true; 406 } else if (oop_cl.failures()) { 407 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has other failures for nmethod " PTR_FORMAT, 408 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm)); 409 _failures = true; 410 } 411 } 412 } 413 } 414 415 bool failures() { return _failures; } 416 }; 417 418 void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const { 419 if (!G1VerifyHeapRegionCodeRoots) { 420 // We're not verifying code roots. 421 return; 422 } 423 if (vo == VerifyOption_G1UseFullMarking) { 424 // Marking verification during a full GC is performed after class 425 // unloading, code cache unloading, etc so the strong code roots 426 // attached to each heap region are in an inconsistent state. They won't 427 // be consistent until the strong code roots are rebuilt after the 428 // actual GC. Skip verifying the strong code roots in this particular 429 // time. 430 assert(VerifyDuringGC, "only way to get here"); 431 return; 432 } 433 434 HeapRegionRemSet* hrrs = rem_set(); 435 size_t strong_code_roots_length = hrrs->strong_code_roots_list_length(); 436 437 // if this region is empty then there should be no entries 438 // on its strong code root list 439 if (is_empty()) { 440 if (strong_code_roots_length > 0) { 441 log_error(gc, verify)("region " HR_FORMAT " is empty but has " SIZE_FORMAT " code root entries", 442 HR_FORMAT_PARAMS(this), strong_code_roots_length); 443 *failures = true; 444 } 445 return; 446 } 447 448 if (is_continues_humongous()) { 449 if (strong_code_roots_length > 0) { 450 log_error(gc, verify)("region " HR_FORMAT " is a continuation of a humongous region but has " SIZE_FORMAT " code root entries", 451 HR_FORMAT_PARAMS(this), strong_code_roots_length); 452 *failures = true; 453 } 454 return; 455 } 456 457 VerifyStrongCodeRootCodeBlobClosure cb_cl(this); 458 strong_code_roots_do(&cb_cl); 459 460 if (cb_cl.failures()) { 461 *failures = true; 462 } 463 } 464 465 void HeapRegion::print() const { print_on(tty); } 466 467 void HeapRegion::print_on(outputStream* st) const { 468 st->print("|%4u", this->_hrm_index); 469 st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT, 470 p2i(bottom()), p2i(top()), p2i(end())); 471 st->print("|%3d%%", (int) ((double) used() * 100 / capacity())); 472 st->print("|%2s", get_short_type_str()); 473 if (in_collection_set()) { 474 st->print("|CS"); 475 } else { 476 st->print("| "); 477 } 478 st->print("|TAMS " PTR_FORMAT ", " PTR_FORMAT "| %s ", 479 p2i(prev_top_at_mark_start()), p2i(next_top_at_mark_start()), rem_set()->get_state_str()); 480 if (UseNUMA) { 481 G1NUMA* numa = G1NUMA::numa(); 482 if (node_index() < numa->num_active_nodes()) { 483 st->print("|%d", numa->numa_id(node_index())); 484 } else { 485 st->print("|-"); 486 } 487 } 488 st->print_cr(""); 489 } 490 491 class G1VerificationClosure : public BasicOopIterateClosure { 492 protected: 493 G1CollectedHeap* _g1h; 494 G1CardTable *_ct; 495 oop _containing_obj; 496 bool _failures; 497 int _n_failures; 498 VerifyOption _vo; 499 public: 500 // _vo == UsePrevMarking -> use "prev" marking information, 501 // _vo == UseNextMarking -> use "next" marking information, 502 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS. 503 G1VerificationClosure(G1CollectedHeap* g1h, VerifyOption vo) : 504 _g1h(g1h), _ct(g1h->card_table()), 505 _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) { 506 } 507 508 void set_containing_obj(oop obj) { 509 _containing_obj = obj; 510 } 511 512 bool failures() { return _failures; } 513 int n_failures() { return _n_failures; } 514 515 void print_object(outputStream* out, oop obj) { 516 #ifdef PRODUCT 517 Klass* k = obj->klass(); 518 const char* class_name = k->external_name(); 519 out->print_cr("class name %s", class_name); 520 #else // PRODUCT 521 obj->print_on(out); 522 #endif // PRODUCT 523 } 524 525 // This closure provides its own oop verification code. 526 debug_only(virtual bool should_verify_oops() { return false; }) 527 }; 528 529 class VerifyLiveClosure : public G1VerificationClosure { 530 public: 531 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {} 532 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 533 virtual void do_oop(oop* p) { do_oop_work(p); } 534 535 template <class T> 536 void do_oop_work(T* p) { 537 assert(_containing_obj != NULL, "Precondition"); 538 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo), 539 "Precondition"); 540 verify_liveness(p); 541 } 542 543 template <class T> 544 void verify_liveness(T* p) { 545 T heap_oop = RawAccess<>::oop_load(p); 546 Log(gc, verify) log; 547 if (!CompressedOops::is_null(heap_oop)) { 548 oop obj = CompressedOops::decode_not_null(heap_oop); 549 bool failed = false; 550 if (!_g1h->is_in(obj) || _g1h->is_obj_dead_cond(obj, _vo)) { 551 MutexLocker x(ParGCRareEvent_lock, 552 Mutex::_no_safepoint_check_flag); 553 554 if (!_failures) { 555 log.error("----------"); 556 } 557 ResourceMark rm; 558 if (!_g1h->is_in(obj)) { 559 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); 560 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT, 561 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from)); 562 LogStream ls(log.error()); 563 print_object(&ls, _containing_obj); 564 HeapRegion* const to = _g1h->heap_region_containing(obj); 565 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s", 566 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str()); 567 } else { 568 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); 569 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj); 570 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region " HR_FORMAT, 571 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from)); 572 LogStream ls(log.error()); 573 print_object(&ls, _containing_obj); 574 log.error("points to dead obj " PTR_FORMAT " in region " HR_FORMAT, 575 p2i(obj), HR_FORMAT_PARAMS(to)); 576 print_object(&ls, obj); 577 } 578 log.error("----------"); 579 _failures = true; 580 failed = true; 581 _n_failures++; 582 } 583 } 584 } 585 }; 586 587 class VerifyRemSetClosure : public G1VerificationClosure { 588 public: 589 VerifyRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {} 590 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 591 virtual void do_oop(oop* p) { do_oop_work(p); } 592 593 template <class T> 594 void do_oop_work(T* p) { 595 assert(_containing_obj != NULL, "Precondition"); 596 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo), 597 "Precondition"); 598 verify_remembered_set(p); 599 } 600 601 template <class T> 602 void verify_remembered_set(T* p) { 603 T heap_oop = RawAccess<>::oop_load(p); 604 Log(gc, verify) log; 605 if (!CompressedOops::is_null(heap_oop)) { 606 oop obj = CompressedOops::decode_not_null(heap_oop); 607 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); 608 HeapRegion* to = _g1h->heap_region_containing(obj); 609 if (from != NULL && to != NULL && 610 from != to && 611 !to->is_pinned() && 612 to->rem_set()->is_complete()) { 613 jbyte cv_obj = *_ct->byte_for_const(_containing_obj); 614 jbyte cv_field = *_ct->byte_for_const(p); 615 const jbyte dirty = G1CardTable::dirty_card_val(); 616 617 bool is_bad = !(from->is_young() 618 || to->rem_set()->contains_reference(p) 619 || (_containing_obj->is_objArray() ? 620 cv_field == dirty : 621 cv_obj == dirty || cv_field == dirty)); 622 if (is_bad) { 623 MutexLocker x(ParGCRareEvent_lock, 624 Mutex::_no_safepoint_check_flag); 625 626 if (!_failures) { 627 log.error("----------"); 628 } 629 log.error("Missing rem set entry:"); 630 log.error("Field " PTR_FORMAT " of obj " PTR_FORMAT " in region " HR_FORMAT, 631 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from)); 632 ResourceMark rm; 633 LogStream ls(log.error()); 634 _containing_obj->print_on(&ls); 635 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s", 636 p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str()); 637 if (oopDesc::is_oop(obj)) { 638 obj->print_on(&ls); 639 } 640 log.error("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field); 641 log.error("----------"); 642 _failures = true; 643 _n_failures++; 644 } 645 } 646 } 647 } 648 }; 649 650 // Closure that applies the given two closures in sequence. 651 class G1Mux2Closure : public BasicOopIterateClosure { 652 OopClosure* _c1; 653 OopClosure* _c2; 654 public: 655 G1Mux2Closure(OopClosure *c1, OopClosure *c2) { _c1 = c1; _c2 = c2; } 656 template <class T> inline void do_oop_work(T* p) { 657 // Apply first closure; then apply the second. 658 _c1->do_oop(p); 659 _c2->do_oop(p); 660 } 661 virtual inline void do_oop(oop* p) { do_oop_work(p); } 662 virtual inline void do_oop(narrowOop* p) { do_oop_work(p); } 663 664 // This closure provides its own oop verification code. 665 debug_only(virtual bool should_verify_oops() { return false; }) 666 }; 667 668 void HeapRegion::verify(VerifyOption vo, 669 bool* failures) const { 670 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 671 *failures = false; 672 HeapWord* p = bottom(); 673 HeapWord* prev_p = NULL; 674 VerifyLiveClosure vl_cl(g1h, vo); 675 VerifyRemSetClosure vr_cl(g1h, vo); 676 bool is_region_humongous = is_humongous(); 677 size_t object_num = 0; 678 while (p < top()) { 679 oop obj = oop(p); 680 size_t obj_size = block_size(p); 681 object_num += 1; 682 683 if (!g1h->is_obj_dead_cond(obj, this, vo)) { 684 if (oopDesc::is_oop(obj)) { 685 Klass* klass = obj->klass(); 686 bool is_metaspace_object = Metaspace::contains(klass); 687 if (!is_metaspace_object) { 688 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " " 689 "not metadata", p2i(klass), p2i(obj)); 690 *failures = true; 691 return; 692 } else if (!klass->is_klass()) { 693 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " " 694 "not a klass", p2i(klass), p2i(obj)); 695 *failures = true; 696 return; 697 } else { 698 vl_cl.set_containing_obj(obj); 699 if (!g1h->collector_state()->in_full_gc() || G1VerifyRSetsDuringFullGC) { 700 // verify liveness and rem_set 701 vr_cl.set_containing_obj(obj); 702 G1Mux2Closure mux(&vl_cl, &vr_cl); 703 obj->oop_iterate(&mux); 704 705 if (vr_cl.failures()) { 706 *failures = true; 707 } 708 if (G1MaxVerifyFailures >= 0 && 709 vr_cl.n_failures() >= G1MaxVerifyFailures) { 710 return; 711 } 712 } else { 713 // verify only liveness 714 obj->oop_iterate(&vl_cl); 715 } 716 if (vl_cl.failures()) { 717 *failures = true; 718 } 719 if (G1MaxVerifyFailures >= 0 && 720 vl_cl.n_failures() >= G1MaxVerifyFailures) { 721 return; 722 } 723 } 724 } else { 725 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj)); 726 *failures = true; 727 return; 728 } 729 } 730 prev_p = p; 731 p += obj_size; 732 } 733 734 if (!is_young() && !is_empty()) { 735 _bot_part.verify(); 736 } 737 738 if (is_region_humongous) { 739 oop obj = oop(this->humongous_start_region()->bottom()); 740 if ((HeapWord*)obj > bottom() || (HeapWord*)obj + obj->size() < bottom()) { 741 log_error(gc, verify)("this humongous region is not part of its' humongous object " PTR_FORMAT, p2i(obj)); 742 *failures = true; 743 return; 744 } 745 } 746 747 if (!is_region_humongous && p != top()) { 748 log_error(gc, verify)("end of last object " PTR_FORMAT " " 749 "does not match top " PTR_FORMAT, p2i(p), p2i(top())); 750 *failures = true; 751 return; 752 } 753 754 HeapWord* the_end = end(); 755 // Do some extra BOT consistency checking for addresses in the 756 // range [top, end). BOT look-ups in this range should yield 757 // top. No point in doing that if top == end (there's nothing there). 758 if (p < the_end) { 759 // Look up top 760 HeapWord* addr_1 = p; 761 HeapWord* b_start_1 = block_start_const(addr_1); 762 if (b_start_1 != p) { 763 log_error(gc, verify)("BOT look up for top: " PTR_FORMAT " " 764 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 765 p2i(addr_1), p2i(b_start_1), p2i(p)); 766 *failures = true; 767 return; 768 } 769 770 // Look up top + 1 771 HeapWord* addr_2 = p + 1; 772 if (addr_2 < the_end) { 773 HeapWord* b_start_2 = block_start_const(addr_2); 774 if (b_start_2 != p) { 775 log_error(gc, verify)("BOT look up for top + 1: " PTR_FORMAT " " 776 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 777 p2i(addr_2), p2i(b_start_2), p2i(p)); 778 *failures = true; 779 return; 780 } 781 } 782 783 // Look up an address between top and end 784 size_t diff = pointer_delta(the_end, p) / 2; 785 HeapWord* addr_3 = p + diff; 786 if (addr_3 < the_end) { 787 HeapWord* b_start_3 = block_start_const(addr_3); 788 if (b_start_3 != p) { 789 log_error(gc, verify)("BOT look up for top + diff: " PTR_FORMAT " " 790 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 791 p2i(addr_3), p2i(b_start_3), p2i(p)); 792 *failures = true; 793 return; 794 } 795 } 796 797 // Look up end - 1 798 HeapWord* addr_4 = the_end - 1; 799 HeapWord* b_start_4 = block_start_const(addr_4); 800 if (b_start_4 != p) { 801 log_error(gc, verify)("BOT look up for end - 1: " PTR_FORMAT " " 802 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 803 p2i(addr_4), p2i(b_start_4), p2i(p)); 804 *failures = true; 805 return; 806 } 807 } 808 809 verify_strong_code_roots(vo, failures); 810 } 811 812 void HeapRegion::verify() const { 813 bool dummy = false; 814 verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy); 815 } 816 817 void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const { 818 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 819 *failures = false; 820 HeapWord* p = bottom(); 821 HeapWord* prev_p = NULL; 822 VerifyRemSetClosure vr_cl(g1h, vo); 823 while (p < top()) { 824 oop obj = oop(p); 825 size_t obj_size = block_size(p); 826 827 if (!g1h->is_obj_dead_cond(obj, this, vo)) { 828 if (oopDesc::is_oop(obj)) { 829 vr_cl.set_containing_obj(obj); 830 obj->oop_iterate(&vr_cl); 831 832 if (vr_cl.failures()) { 833 *failures = true; 834 } 835 if (G1MaxVerifyFailures >= 0 && 836 vr_cl.n_failures() >= G1MaxVerifyFailures) { 837 return; 838 } 839 } else { 840 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj)); 841 *failures = true; 842 return; 843 } 844 } 845 846 prev_p = p; 847 p += obj_size; 848 } 849 } 850 851 void HeapRegion::verify_rem_set() const { 852 bool failures = false; 853 verify_rem_set(VerifyOption_G1UsePrevMarking, &failures); 854 guarantee(!failures, "HeapRegion RemSet verification failed"); 855 } 856 857 void HeapRegion::clear(bool mangle_space) { 858 set_top(bottom()); 859 set_compaction_top(bottom()); 860 861 if (ZapUnusedHeapArea && mangle_space) { 862 mangle_unused_area(); 863 } 864 reset_bot(); 865 } 866 867 #ifndef PRODUCT 868 void HeapRegion::mangle_unused_area() { 869 SpaceMangler::mangle_region(MemRegion(top(), end())); 870 } 871 #endif 872 873 HeapWord* HeapRegion::initialize_threshold() { 874 return _bot_part.initialize_threshold(); 875 } 876 877 HeapWord* HeapRegion::cross_threshold(HeapWord* start, HeapWord* end) { 878 _bot_part.alloc_block(start, end); 879 return _bot_part.threshold(); 880 } 881 882 void HeapRegion::object_iterate(ObjectClosure* blk) { 883 HeapWord* p = bottom(); 884 while (p < top()) { 885 if (block_is_obj(p)) { 886 blk->do_object(oop(p)); 887 } 888 p += block_size(p); 889 } 890 }