1 /* 2 * Copyright (c) 2001, 2018, 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/g1HeapRegionTraceType.hpp" 30 #include "gc/g1/g1OopClosures.inline.hpp" 31 #include "gc/g1/heapRegion.inline.hpp" 32 #include "gc/g1/heapRegionBounds.inline.hpp" 33 #include "gc/g1/heapRegionManager.inline.hpp" 34 #include "gc/g1/heapRegionRemSet.hpp" 35 #include "gc/g1/heapRegionTracer.hpp" 36 #include "gc/shared/genOopClosures.inline.hpp" 37 #include "gc/shared/space.inline.hpp" 38 #include "logging/log.hpp" 39 #include "logging/logStream.hpp" 40 #include "memory/iterator.inline.hpp" 41 #include "memory/resourceArea.hpp" 42 #include "oops/access.inline.hpp" 43 #include "oops/compressedOops.inline.hpp" 44 #include "oops/oop.inline.hpp" 45 #include "runtime/atomic.hpp" 46 #include "runtime/orderAccess.hpp" 47 #include "utilities/growableArray.hpp" 48 49 int HeapRegion::LogOfHRGrainBytes = 0; 50 int HeapRegion::LogOfHRGrainWords = 0; 51 size_t HeapRegion::GrainBytes = 0; 52 size_t HeapRegion::GrainWords = 0; 53 size_t HeapRegion::CardsPerRegion = 0; 54 55 size_t HeapRegion::max_region_size() { 56 return HeapRegionBounds::max_size(); 57 } 58 59 size_t HeapRegion::min_region_size_in_words() { 60 return HeapRegionBounds::min_size() >> LogHeapWordSize; 61 } 62 63 void HeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) { 64 size_t region_size = G1HeapRegionSize; 65 if (FLAG_IS_DEFAULT(G1HeapRegionSize)) { 66 size_t average_heap_size = (initial_heap_size + max_heap_size) / 2; 67 region_size = MAX2(average_heap_size / HeapRegionBounds::target_number(), 68 HeapRegionBounds::min_size()); 69 if (DumpSharedSpaces && max_heap_size >= 128*M && region_size < 8*M) { 70 // CDS archived heap supports up to 32G heaps, with region size up to 8MB. 71 // At CDS dump time, if we use small regions for G1, the CARC and OARC regions may end up 72 // in the same 8MB block. At run time with a large heap, G1CollectedHeap::alloc_archive_regions 73 // might fail because CARC and OARC will end up in the same G1 region. 74 region_size = 8*M; 75 } 76 } 77 78 int region_size_log = log2_long((jlong) region_size); 79 // Recalculate the region size to make sure it's a power of 80 // 2. This means that region_size is the largest power of 2 that's 81 // <= what we've calculated so far. 82 region_size = ((size_t)1 << region_size_log); 83 84 // Now make sure that we don't go over or under our limits. 85 if (region_size < HeapRegionBounds::min_size()) { 86 region_size = HeapRegionBounds::min_size(); 87 } else if (region_size > HeapRegionBounds::max_size()) { 88 region_size = HeapRegionBounds::max_size(); 89 } 90 91 // And recalculate the log. 92 region_size_log = log2_long((jlong) region_size); 93 94 // Now, set up the globals. 95 guarantee(LogOfHRGrainBytes == 0, "we should only set it once"); 96 LogOfHRGrainBytes = region_size_log; 97 98 guarantee(LogOfHRGrainWords == 0, "we should only set it once"); 99 LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize; 100 101 guarantee(GrainBytes == 0, "we should only set it once"); 102 // The cast to int is safe, given that we've bounded region_size by 103 // MIN_REGION_SIZE and MAX_REGION_SIZE. 104 GrainBytes = region_size; 105 log_info(gc, heap)("Heap region size: " SIZE_FORMAT "M", GrainBytes / M); 106 107 guarantee(GrainWords == 0, "we should only set it once"); 108 GrainWords = GrainBytes >> LogHeapWordSize; 109 guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity"); 110 111 guarantee(CardsPerRegion == 0, "we should only set it once"); 112 CardsPerRegion = GrainBytes >> G1CardTable::card_shift; 113 114 if (G1HeapRegionSize != GrainBytes) { 115 FLAG_SET_ERGO(size_t, G1HeapRegionSize, GrainBytes); 116 } 117 } 118 119 void HeapRegion::hr_clear(bool keep_remset, bool clear_space, bool locked) { 120 assert(_humongous_start_region == NULL, 121 "we should have already filtered out humongous regions"); 122 assert(!in_collection_set(), 123 "Should not clear heap region %u in the collection set", hrm_index()); 124 125 set_young_index_in_cset(-1); 126 uninstall_surv_rate_group(); 127 set_free(); 128 reset_pre_dummy_top(); 129 130 if (!keep_remset) { 131 if (locked) { 132 rem_set()->clear_locked(); 133 } else { 134 rem_set()->clear(); 135 } 136 } 137 138 zero_marked_bytes(); 139 140 init_top_at_mark_start(); 141 if (clear_space) clear(SpaceDecorator::Mangle); 142 } 143 144 void HeapRegion::clear_cardtable() { 145 G1CardTable* ct = G1CollectedHeap::heap()->card_table(); 146 ct->clear(MemRegion(bottom(), end())); 147 } 148 149 void HeapRegion::calc_gc_efficiency() { 150 // GC efficiency is the ratio of how much space would be 151 // reclaimed over how long we predict it would take to reclaim it. 152 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 153 G1Policy* g1p = g1h->g1_policy(); 154 155 // Retrieve a prediction of the elapsed time for this region for 156 // a mixed gc because the region will only be evacuated during a 157 // mixed gc. 158 double region_elapsed_time_ms = 159 g1p->predict_region_elapsed_time_ms(this, false /* for_young_gc */); 160 _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms; 161 } 162 163 void HeapRegion::set_free() { 164 report_region_type_change(G1HeapRegionTraceType::Free); 165 _type.set_free(); 166 } 167 168 void HeapRegion::set_eden() { 169 report_region_type_change(G1HeapRegionTraceType::Eden); 170 _type.set_eden(); 171 } 172 173 void HeapRegion::set_eden_pre_gc() { 174 report_region_type_change(G1HeapRegionTraceType::Eden); 175 _type.set_eden_pre_gc(); 176 } 177 178 void HeapRegion::set_survivor() { 179 report_region_type_change(G1HeapRegionTraceType::Survivor); 180 _type.set_survivor(); 181 } 182 183 void HeapRegion::move_to_old() { 184 if (_type.relabel_as_old()) { 185 report_region_type_change(G1HeapRegionTraceType::Old); 186 } 187 } 188 189 void HeapRegion::set_old() { 190 report_region_type_change(G1HeapRegionTraceType::Old); 191 _type.set_old(); 192 } 193 194 void HeapRegion::set_open_archive() { 195 report_region_type_change(G1HeapRegionTraceType::OpenArchive); 196 _type.set_open_archive(); 197 } 198 199 void HeapRegion::set_closed_archive() { 200 report_region_type_change(G1HeapRegionTraceType::ClosedArchive); 201 _type.set_closed_archive(); 202 } 203 204 void HeapRegion::set_starts_humongous(HeapWord* obj_top, size_t fill_size) { 205 assert(!is_humongous(), "sanity / pre-condition"); 206 assert(top() == bottom(), "should be empty"); 207 208 report_region_type_change(G1HeapRegionTraceType::StartsHumongous); 209 _type.set_starts_humongous(); 210 _humongous_start_region = this; 211 212 _bot_part.set_for_starts_humongous(obj_top, fill_size); 213 } 214 215 void HeapRegion::set_continues_humongous(HeapRegion* first_hr) { 216 assert(!is_humongous(), "sanity / pre-condition"); 217 assert(top() == bottom(), "should be empty"); 218 assert(first_hr->is_starts_humongous(), "pre-condition"); 219 220 report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous); 221 _type.set_continues_humongous(); 222 _humongous_start_region = first_hr; 223 224 _bot_part.set_object_can_span(true); 225 } 226 227 void HeapRegion::clear_humongous() { 228 assert(is_humongous(), "pre-condition"); 229 230 assert(capacity() == HeapRegion::GrainBytes, "pre-condition"); 231 _humongous_start_region = NULL; 232 233 _bot_part.set_object_can_span(false); 234 } 235 236 HeapRegion::HeapRegion(uint hrm_index, 237 G1BlockOffsetTable* bot, 238 MemRegion mr) : 239 G1ContiguousSpace(bot), 240 _hrm_index(hrm_index), 241 _humongous_start_region(NULL), 242 _evacuation_failed(false), 243 _prev_marked_bytes(0), _next_marked_bytes(0), _gc_efficiency(0.0), 244 _next(NULL), _prev(NULL), 245 #ifdef ASSERT 246 _containing_set(NULL), 247 #endif // ASSERT 248 _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1), 249 _rem_set(NULL), _recorded_rs_length(0), _predicted_elapsed_time_ms(0) 250 { 251 _rem_set = new HeapRegionRemSet(bot, this); 252 253 initialize(mr); 254 } 255 256 void HeapRegion::initialize(MemRegion mr, bool clear_space, bool mangle_space) { 257 assert(_rem_set->is_empty(), "Remembered set must be empty"); 258 259 G1ContiguousSpace::initialize(mr, clear_space, mangle_space); 260 261 hr_clear(false /*par*/, false /*clear_space*/); 262 set_top(bottom()); 263 } 264 265 void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) { 266 HeapRegionTracer::send_region_type_change(_hrm_index, 267 get_trace_type(), 268 to, 269 (uintptr_t)bottom(), 270 used()); 271 } 272 273 void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark, 274 bool during_conc_mark) { 275 // We always recreate the prev marking info and we'll explicitly 276 // mark all objects we find to be self-forwarded on the prev 277 // bitmap. So all objects need to be below PTAMS. 278 _prev_marked_bytes = 0; 279 280 if (during_initial_mark) { 281 // During initial-mark, we'll also explicitly mark all objects 282 // we find to be self-forwarded on the next bitmap. So all 283 // objects need to be below NTAMS. 284 _next_top_at_mark_start = top(); 285 _next_marked_bytes = 0; 286 } else if (during_conc_mark) { 287 // During concurrent mark, all objects in the CSet (including 288 // the ones we find to be self-forwarded) are implicitly live. 289 // So all objects need to be above NTAMS. 290 _next_top_at_mark_start = bottom(); 291 _next_marked_bytes = 0; 292 } 293 } 294 295 void HeapRegion::note_self_forwarding_removal_end(size_t marked_bytes) { 296 assert(marked_bytes <= used(), 297 "marked: " SIZE_FORMAT " used: " SIZE_FORMAT, marked_bytes, used()); 298 _prev_top_at_mark_start = top(); 299 _prev_marked_bytes = marked_bytes; 300 } 301 302 // Code roots support 303 304 void HeapRegion::add_strong_code_root(nmethod* nm) { 305 HeapRegionRemSet* hrrs = rem_set(); 306 hrrs->add_strong_code_root(nm); 307 } 308 309 void HeapRegion::add_strong_code_root_locked(nmethod* nm) { 310 assert_locked_or_safepoint(CodeCache_lock); 311 HeapRegionRemSet* hrrs = rem_set(); 312 hrrs->add_strong_code_root_locked(nm); 313 } 314 315 void HeapRegion::remove_strong_code_root(nmethod* nm) { 316 HeapRegionRemSet* hrrs = rem_set(); 317 hrrs->remove_strong_code_root(nm); 318 } 319 320 void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const { 321 HeapRegionRemSet* hrrs = rem_set(); 322 hrrs->strong_code_roots_do(blk); 323 } 324 325 class VerifyStrongCodeRootOopClosure: public OopClosure { 326 const HeapRegion* _hr; 327 bool _failures; 328 bool _has_oops_in_region; 329 330 template <class T> void do_oop_work(T* p) { 331 T heap_oop = RawAccess<>::oop_load(p); 332 if (!CompressedOops::is_null(heap_oop)) { 333 oop obj = CompressedOops::decode_not_null(heap_oop); 334 335 // Note: not all the oops embedded in the nmethod are in the 336 // current region. We only look at those which are. 337 if (_hr->is_in(obj)) { 338 // Object is in the region. Check that its less than top 339 if (_hr->top() <= (HeapWord*)obj) { 340 // Object is above top 341 log_error(gc, verify)("Object " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ") is above top " PTR_FORMAT, 342 p2i(obj), p2i(_hr->bottom()), p2i(_hr->end()), p2i(_hr->top())); 343 _failures = true; 344 return; 345 } 346 // Nmethod has at least one oop in the current region 347 _has_oops_in_region = true; 348 } 349 } 350 } 351 352 public: 353 VerifyStrongCodeRootOopClosure(const HeapRegion* hr): 354 _hr(hr), _failures(false), _has_oops_in_region(false) {} 355 356 void do_oop(narrowOop* p) { do_oop_work(p); } 357 void do_oop(oop* p) { do_oop_work(p); } 358 359 bool failures() { return _failures; } 360 bool has_oops_in_region() { return _has_oops_in_region; } 361 }; 362 363 class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure { 364 const HeapRegion* _hr; 365 bool _failures; 366 public: 367 VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) : 368 _hr(hr), _failures(false) {} 369 370 void do_code_blob(CodeBlob* cb) { 371 nmethod* nm = (cb == NULL) ? NULL : cb->as_compiled_method()->as_nmethod_or_null(); 372 if (nm != NULL) { 373 // Verify that the nemthod is live 374 if (!nm->is_alive()) { 375 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has dead nmethod " PTR_FORMAT " in its strong code roots", 376 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm)); 377 _failures = true; 378 } else { 379 VerifyStrongCodeRootOopClosure oop_cl(_hr); 380 nm->oops_do(&oop_cl); 381 if (!oop_cl.has_oops_in_region()) { 382 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has nmethod " PTR_FORMAT " in its strong code roots with no pointers into region", 383 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm)); 384 _failures = true; 385 } else if (oop_cl.failures()) { 386 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] has other failures for nmethod " PTR_FORMAT, 387 p2i(_hr->bottom()), p2i(_hr->end()), p2i(nm)); 388 _failures = true; 389 } 390 } 391 } 392 } 393 394 bool failures() { return _failures; } 395 }; 396 397 void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const { 398 if (!G1VerifyHeapRegionCodeRoots) { 399 // We're not verifying code roots. 400 return; 401 } 402 if (vo == VerifyOption_G1UseFullMarking) { 403 // Marking verification during a full GC is performed after class 404 // unloading, code cache unloading, etc so the strong code roots 405 // attached to each heap region are in an inconsistent state. They won't 406 // be consistent until the strong code roots are rebuilt after the 407 // actual GC. Skip verifying the strong code roots in this particular 408 // time. 409 assert(VerifyDuringGC, "only way to get here"); 410 return; 411 } 412 413 HeapRegionRemSet* hrrs = rem_set(); 414 size_t strong_code_roots_length = hrrs->strong_code_roots_list_length(); 415 416 // if this region is empty then there should be no entries 417 // on its strong code root list 418 if (is_empty()) { 419 if (strong_code_roots_length > 0) { 420 log_error(gc, verify)("region [" PTR_FORMAT "," PTR_FORMAT "] is empty but has " SIZE_FORMAT " code root entries", 421 p2i(bottom()), p2i(end()), strong_code_roots_length); 422 *failures = true; 423 } 424 return; 425 } 426 427 if (is_continues_humongous()) { 428 if (strong_code_roots_length > 0) { 429 log_error(gc, verify)("region " HR_FORMAT " is a continuation of a humongous region but has " SIZE_FORMAT " code root entries", 430 HR_FORMAT_PARAMS(this), strong_code_roots_length); 431 *failures = true; 432 } 433 return; 434 } 435 436 VerifyStrongCodeRootCodeBlobClosure cb_cl(this); 437 strong_code_roots_do(&cb_cl); 438 439 if (cb_cl.failures()) { 440 *failures = true; 441 } 442 } 443 444 void HeapRegion::print() const { print_on(tty); } 445 void HeapRegion::print_on(outputStream* st) const { 446 st->print("|%4u", this->_hrm_index); 447 st->print("|" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT, 448 p2i(bottom()), p2i(top()), p2i(end())); 449 st->print("|%3d%%", (int) ((double) used() * 100 / capacity())); 450 st->print("|%2s", get_short_type_str()); 451 if (in_collection_set()) { 452 st->print("|CS"); 453 } else { 454 st->print("| "); 455 } 456 st->print_cr("|TAMS " PTR_FORMAT ", " PTR_FORMAT "| %s ", 457 p2i(prev_top_at_mark_start()), p2i(next_top_at_mark_start()), rem_set()->get_state_str()); 458 } 459 460 class G1VerificationClosure : public BasicOopIterateClosure { 461 protected: 462 G1CollectedHeap* _g1h; 463 G1CardTable *_ct; 464 oop _containing_obj; 465 bool _failures; 466 int _n_failures; 467 VerifyOption _vo; 468 public: 469 // _vo == UsePrevMarking -> use "prev" marking information, 470 // _vo == UseNextMarking -> use "next" marking information, 471 // _vo == UseFullMarking -> use "next" marking bitmap but no TAMS. 472 G1VerificationClosure(G1CollectedHeap* g1h, VerifyOption vo) : 473 _g1h(g1h), _ct(g1h->card_table()), 474 _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) { 475 } 476 477 void set_containing_obj(oop obj) { 478 _containing_obj = obj; 479 } 480 481 bool failures() { return _failures; } 482 int n_failures() { return _n_failures; } 483 484 void print_object(outputStream* out, oop obj) { 485 #ifdef PRODUCT 486 Klass* k = obj->klass(); 487 const char* class_name = k->external_name(); 488 out->print_cr("class name %s", class_name); 489 #else // PRODUCT 490 obj->print_on(out); 491 #endif // PRODUCT 492 } 493 494 // This closure provides its own oop verification code. 495 debug_only(virtual bool should_verify_oops() { return false; }) 496 }; 497 498 class VerifyLiveClosure : public G1VerificationClosure { 499 public: 500 VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {} 501 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 502 virtual void do_oop(oop* p) { do_oop_work(p); } 503 504 template <class T> 505 void do_oop_work(T* p) { 506 assert(_containing_obj != NULL, "Precondition"); 507 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo), 508 "Precondition"); 509 verify_liveness(p); 510 } 511 512 template <class T> 513 void verify_liveness(T* p) { 514 T heap_oop = RawAccess<>::oop_load(p); 515 Log(gc, verify) log; 516 if (!CompressedOops::is_null(heap_oop)) { 517 oop obj = CompressedOops::decode_not_null(heap_oop); 518 bool failed = false; 519 if (!_g1h->is_in_closed_subset(obj) || _g1h->is_obj_dead_cond(obj, _vo)) { 520 MutexLockerEx x(ParGCRareEvent_lock, 521 Mutex::_no_safepoint_check_flag); 522 523 if (!_failures) { 524 log.error("----------"); 525 } 526 ResourceMark rm; 527 if (!_g1h->is_in_closed_subset(obj)) { 528 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); 529 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")", 530 p2i(p), p2i(_containing_obj), p2i(from->bottom()), p2i(from->end())); 531 LogStream ls(log.error()); 532 print_object(&ls, _containing_obj); 533 HeapRegion* const to = _g1h->heap_region_containing(obj); 534 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s", p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str()); 535 } else { 536 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); 537 HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj); 538 log.error("Field " PTR_FORMAT " of live obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")", 539 p2i(p), p2i(_containing_obj), p2i(from->bottom()), p2i(from->end())); 540 LogStream ls(log.error()); 541 print_object(&ls, _containing_obj); 542 log.error("points to dead obj " PTR_FORMAT " in region [" PTR_FORMAT ", " PTR_FORMAT ")", 543 p2i(obj), p2i(to->bottom()), p2i(to->end())); 544 print_object(&ls, obj); 545 } 546 log.error("----------"); 547 _failures = true; 548 failed = true; 549 _n_failures++; 550 } 551 } 552 } 553 }; 554 555 class VerifyRemSetClosure : public G1VerificationClosure { 556 public: 557 VerifyRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) : G1VerificationClosure(g1h, vo) {} 558 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 559 virtual void do_oop(oop* p) { do_oop_work(p); } 560 561 template <class T> 562 void do_oop_work(T* p) { 563 assert(_containing_obj != NULL, "Precondition"); 564 assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo), 565 "Precondition"); 566 verify_remembered_set(p); 567 } 568 569 template <class T> 570 void verify_remembered_set(T* p) { 571 T heap_oop = RawAccess<>::oop_load(p); 572 Log(gc, verify) log; 573 if (!CompressedOops::is_null(heap_oop)) { 574 oop obj = CompressedOops::decode_not_null(heap_oop); 575 HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); 576 HeapRegion* to = _g1h->heap_region_containing(obj); 577 if (from != NULL && to != NULL && 578 from != to && 579 !to->is_pinned() && 580 to->rem_set()->is_complete()) { 581 jbyte cv_obj = *_ct->byte_for_const(_containing_obj); 582 jbyte cv_field = *_ct->byte_for_const(p); 583 const jbyte dirty = G1CardTable::dirty_card_val(); 584 585 bool is_bad = !(from->is_young() 586 || to->rem_set()->contains_reference(p) 587 || (_containing_obj->is_objArray() ? 588 cv_field == dirty : 589 cv_obj == dirty || cv_field == dirty)); 590 if (is_bad) { 591 MutexLockerEx x(ParGCRareEvent_lock, 592 Mutex::_no_safepoint_check_flag); 593 594 if (!_failures) { 595 log.error("----------"); 596 } 597 log.error("Missing rem set entry:"); 598 log.error("Field " PTR_FORMAT " of obj " PTR_FORMAT ", in region " HR_FORMAT, 599 p2i(p), p2i(_containing_obj), HR_FORMAT_PARAMS(from)); 600 ResourceMark rm; 601 LogStream ls(log.error()); 602 _containing_obj->print_on(&ls); 603 log.error("points to obj " PTR_FORMAT " in region " HR_FORMAT " remset %s", p2i(obj), HR_FORMAT_PARAMS(to), to->rem_set()->get_state_str()); 604 if (oopDesc::is_oop(obj)) { 605 obj->print_on(&ls); 606 } 607 log.error("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field); 608 log.error("----------"); 609 _failures = true; 610 _n_failures++; 611 } 612 } 613 } 614 } 615 }; 616 617 // Closure that applies the given two closures in sequence. 618 class G1Mux2Closure : public BasicOopIterateClosure { 619 OopClosure* _c1; 620 OopClosure* _c2; 621 public: 622 G1Mux2Closure(OopClosure *c1, OopClosure *c2) { _c1 = c1; _c2 = c2; } 623 template <class T> inline void do_oop_work(T* p) { 624 // Apply first closure; then apply the second. 625 _c1->do_oop(p); 626 _c2->do_oop(p); 627 } 628 virtual inline void do_oop(oop* p) { do_oop_work(p); } 629 virtual inline void do_oop(narrowOop* p) { do_oop_work(p); } 630 631 // This closure provides its own oop verification code. 632 debug_only(virtual bool should_verify_oops() { return false; }) 633 }; 634 635 // This really ought to be commoned up into OffsetTableContigSpace somehow. 636 // We would need a mechanism to make that code skip dead objects. 637 638 void HeapRegion::verify(VerifyOption vo, 639 bool* failures) const { 640 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 641 *failures = false; 642 HeapWord* p = bottom(); 643 HeapWord* prev_p = NULL; 644 VerifyLiveClosure vl_cl(g1h, vo); 645 VerifyRemSetClosure vr_cl(g1h, vo); 646 bool is_region_humongous = is_humongous(); 647 size_t object_num = 0; 648 while (p < top()) { 649 oop obj = oop(p); 650 size_t obj_size = block_size(p); 651 object_num += 1; 652 653 if (!g1h->is_obj_dead_cond(obj, this, vo)) { 654 if (oopDesc::is_oop(obj)) { 655 Klass* klass = obj->klass(); 656 bool is_metaspace_object = Metaspace::contains(klass); 657 if (!is_metaspace_object) { 658 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " " 659 "not metadata", p2i(klass), p2i(obj)); 660 *failures = true; 661 return; 662 } else if (!klass->is_klass()) { 663 log_error(gc, verify)("klass " PTR_FORMAT " of object " PTR_FORMAT " " 664 "not a klass", p2i(klass), p2i(obj)); 665 *failures = true; 666 return; 667 } else { 668 vl_cl.set_containing_obj(obj); 669 if (!g1h->collector_state()->in_full_gc() || G1VerifyRSetsDuringFullGC) { 670 // verify liveness and rem_set 671 vr_cl.set_containing_obj(obj); 672 G1Mux2Closure mux(&vl_cl, &vr_cl); 673 obj->oop_iterate(&mux); 674 675 if (vr_cl.failures()) { 676 *failures = true; 677 } 678 if (G1MaxVerifyFailures >= 0 && 679 vr_cl.n_failures() >= G1MaxVerifyFailures) { 680 return; 681 } 682 } else { 683 // verify only liveness 684 obj->oop_iterate(&vl_cl); 685 } 686 if (vl_cl.failures()) { 687 *failures = true; 688 } 689 if (G1MaxVerifyFailures >= 0 && 690 vl_cl.n_failures() >= G1MaxVerifyFailures) { 691 return; 692 } 693 } 694 } else { 695 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj)); 696 *failures = true; 697 return; 698 } 699 } 700 prev_p = p; 701 p += obj_size; 702 } 703 704 if (!is_young() && !is_empty()) { 705 _bot_part.verify(); 706 } 707 708 if (is_region_humongous) { 709 oop obj = oop(this->humongous_start_region()->bottom()); 710 if ((HeapWord*)obj > bottom() || (HeapWord*)obj + obj->size() < bottom()) { 711 log_error(gc, verify)("this humongous region is not part of its' humongous object " PTR_FORMAT, p2i(obj)); 712 *failures = true; 713 return; 714 } 715 } 716 717 if (!is_region_humongous && p != top()) { 718 log_error(gc, verify)("end of last object " PTR_FORMAT " " 719 "does not match top " PTR_FORMAT, p2i(p), p2i(top())); 720 *failures = true; 721 return; 722 } 723 724 HeapWord* the_end = end(); 725 // Do some extra BOT consistency checking for addresses in the 726 // range [top, end). BOT look-ups in this range should yield 727 // top. No point in doing that if top == end (there's nothing there). 728 if (p < the_end) { 729 // Look up top 730 HeapWord* addr_1 = p; 731 HeapWord* b_start_1 = _bot_part.block_start_const(addr_1); 732 if (b_start_1 != p) { 733 log_error(gc, verify)("BOT look up for top: " PTR_FORMAT " " 734 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 735 p2i(addr_1), p2i(b_start_1), p2i(p)); 736 *failures = true; 737 return; 738 } 739 740 // Look up top + 1 741 HeapWord* addr_2 = p + 1; 742 if (addr_2 < the_end) { 743 HeapWord* b_start_2 = _bot_part.block_start_const(addr_2); 744 if (b_start_2 != p) { 745 log_error(gc, verify)("BOT look up for top + 1: " PTR_FORMAT " " 746 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 747 p2i(addr_2), p2i(b_start_2), p2i(p)); 748 *failures = true; 749 return; 750 } 751 } 752 753 // Look up an address between top and end 754 size_t diff = pointer_delta(the_end, p) / 2; 755 HeapWord* addr_3 = p + diff; 756 if (addr_3 < the_end) { 757 HeapWord* b_start_3 = _bot_part.block_start_const(addr_3); 758 if (b_start_3 != p) { 759 log_error(gc, verify)("BOT look up for top + diff: " PTR_FORMAT " " 760 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 761 p2i(addr_3), p2i(b_start_3), p2i(p)); 762 *failures = true; 763 return; 764 } 765 } 766 767 // Look up end - 1 768 HeapWord* addr_4 = the_end - 1; 769 HeapWord* b_start_4 = _bot_part.block_start_const(addr_4); 770 if (b_start_4 != p) { 771 log_error(gc, verify)("BOT look up for end - 1: " PTR_FORMAT " " 772 " yielded " PTR_FORMAT ", expecting " PTR_FORMAT, 773 p2i(addr_4), p2i(b_start_4), p2i(p)); 774 *failures = true; 775 return; 776 } 777 } 778 779 verify_strong_code_roots(vo, failures); 780 } 781 782 void HeapRegion::verify() const { 783 bool dummy = false; 784 verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy); 785 } 786 787 void HeapRegion::verify_rem_set(VerifyOption vo, bool* failures) const { 788 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 789 *failures = false; 790 HeapWord* p = bottom(); 791 HeapWord* prev_p = NULL; 792 VerifyRemSetClosure vr_cl(g1h, vo); 793 while (p < top()) { 794 oop obj = oop(p); 795 size_t obj_size = block_size(p); 796 797 if (!g1h->is_obj_dead_cond(obj, this, vo)) { 798 if (oopDesc::is_oop(obj)) { 799 vr_cl.set_containing_obj(obj); 800 obj->oop_iterate(&vr_cl); 801 802 if (vr_cl.failures()) { 803 *failures = true; 804 } 805 if (G1MaxVerifyFailures >= 0 && 806 vr_cl.n_failures() >= G1MaxVerifyFailures) { 807 return; 808 } 809 } else { 810 log_error(gc, verify)(PTR_FORMAT " not an oop", p2i(obj)); 811 *failures = true; 812 return; 813 } 814 } 815 816 prev_p = p; 817 p += obj_size; 818 } 819 } 820 821 void HeapRegion::verify_rem_set() const { 822 bool failures = false; 823 verify_rem_set(VerifyOption_G1UsePrevMarking, &failures); 824 guarantee(!failures, "HeapRegion RemSet verification failed"); 825 } 826 827 void HeapRegion::prepare_for_compaction(CompactPoint* cp) { 828 // Not used for G1 anymore, but pure virtual in Space. 829 ShouldNotReachHere(); 830 } 831 832 // G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go 833 // away eventually. 834 835 void G1ContiguousSpace::clear(bool mangle_space) { 836 set_top(bottom()); 837 CompactibleSpace::clear(mangle_space); 838 reset_bot(); 839 } 840 #ifndef PRODUCT 841 void G1ContiguousSpace::mangle_unused_area() { 842 mangle_unused_area_complete(); 843 } 844 845 void G1ContiguousSpace::mangle_unused_area_complete() { 846 SpaceMangler::mangle_region(MemRegion(top(), end())); 847 } 848 #endif 849 850 void G1ContiguousSpace::print() const { 851 print_short(); 852 tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " 853 INTPTR_FORMAT ", " INTPTR_FORMAT ")", 854 p2i(bottom()), p2i(top()), p2i(_bot_part.threshold()), p2i(end())); 855 } 856 857 HeapWord* G1ContiguousSpace::initialize_threshold() { 858 return _bot_part.initialize_threshold(); 859 } 860 861 HeapWord* G1ContiguousSpace::cross_threshold(HeapWord* start, 862 HeapWord* end) { 863 _bot_part.alloc_block(start, end); 864 return _bot_part.threshold(); 865 } 866 867 void G1ContiguousSpace::safe_object_iterate(ObjectClosure* blk) { 868 object_iterate(blk); 869 } 870 871 void G1ContiguousSpace::object_iterate(ObjectClosure* blk) { 872 HeapWord* p = bottom(); 873 while (p < top()) { 874 if (block_is_obj(p)) { 875 blk->do_object(oop(p)); 876 } 877 p += block_size(p); 878 } 879 } 880 881 G1ContiguousSpace::G1ContiguousSpace(G1BlockOffsetTable* bot) : 882 _bot_part(bot, this), 883 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true) 884 { 885 } 886 887 void G1ContiguousSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) { 888 CompactibleSpace::initialize(mr, clear_space, mangle_space); 889 _top = bottom(); 890 set_saved_mark_word(NULL); 891 reset_bot(); 892 }