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 #ifndef SHARE_GC_G1_HEAPREGION_HPP 26 #define SHARE_GC_G1_HEAPREGION_HPP 27 28 #include "gc/g1/g1BlockOffsetTable.hpp" 29 #include "gc/g1/g1HeapRegionTraceType.hpp" 30 #include "gc/g1/heapRegionTracer.hpp" 31 #include "gc/g1/heapRegionType.hpp" 32 #include "gc/g1/survRateGroup.hpp" 33 #include "gc/shared/ageTable.hpp" 34 #include "gc/shared/spaceDecorator.hpp" 35 #include "gc/shared/verifyOption.hpp" 36 #include "runtime/mutex.hpp" 37 #include "utilities/macros.hpp" 38 39 class G1CollectedHeap; 40 class G1CMBitMap; 41 class G1Predictions; 42 class HeapRegionRemSet; 43 class HeapRegion; 44 class HeapRegionSetBase; 45 class nmethod; 46 47 #define HR_FORMAT "%u:(%s)[" PTR_FORMAT "," PTR_FORMAT "," PTR_FORMAT "]" 48 #define HR_FORMAT_PARAMS(_hr_) \ 49 (_hr_)->hrm_index(), \ 50 (_hr_)->get_short_type_str(), \ 51 p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end()) 52 53 // sentinel value for hrm_index 54 #define G1_NO_HRM_INDEX ((uint) -1) 55 56 // A HeapRegion is the smallest piece of a G1CollectedHeap that 57 // can be collected independently. 58 59 // Each heap region is self contained. top() and end() can never 60 // be set beyond the end of the region. For humongous objects, 61 // the first region is a StartsHumongous region. If the humongous 62 // object is larger than a heap region, the following regions will 63 // be of type ContinuesHumongous. In this case the top() of the 64 // StartHumongous region and all ContinuesHumongous regions except 65 // the last will point to their own end. The last ContinuesHumongous 66 // region may have top() equal the end of object if there isn't 67 // room for filler objects to pad out to the end of the region. 68 class HeapRegion : public CHeapObj<mtGC> { 69 friend class VMStructs; 70 71 HeapWord* const _bottom; 72 HeapWord* const _end; 73 74 HeapWord* volatile _top; 75 HeapWord* _compaction_top; 76 77 G1BlockOffsetTablePart _bot_part; 78 Mutex _par_alloc_lock; 79 // When we need to retire an allocation region, while other threads 80 // are also concurrently trying to allocate into it, we typically 81 // allocate a dummy object at the end of the region to ensure that 82 // no more allocations can take place in it. However, sometimes we 83 // want to know where the end of the last "real" object we allocated 84 // into the region was and this is what this keeps track. 85 HeapWord* _pre_dummy_top; 86 87 public: 88 HeapWord* bottom() const { return _bottom; } 89 HeapWord* end() const { return _end; } 90 91 void set_compaction_top(HeapWord* compaction_top) { _compaction_top = compaction_top; } 92 HeapWord* compaction_top() const { return _compaction_top; } 93 94 void set_top(HeapWord* value) { _top = value; } 95 HeapWord* top() const { return _top; } 96 97 // See the comment above in the declaration of _pre_dummy_top for an 98 // explanation of what it is. 99 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 100 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 101 _pre_dummy_top = pre_dummy_top; 102 } 103 HeapWord* pre_dummy_top() { return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; } 104 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 105 106 // Returns true iff the given the heap region contains the 107 // given address as part of an allocated object. This may 108 // be a potentially, so we restrict its use to assertion checks only. 109 bool is_in(const void* p) const { 110 return is_in_reserved(p); 111 } 112 bool is_in(oop obj) const { 113 return is_in((void*)obj); 114 } 115 // Returns true iff the given reserved memory of the space contains the 116 // given address. 117 bool is_in_reserved(const void* p) const { return _bottom <= p && p < _end; } 118 119 size_t capacity() const { return byte_size(bottom(), end()); } 120 size_t used() const { return byte_size(bottom(), top()); } 121 size_t free() const { return byte_size(top(), end()); } 122 123 bool is_empty() const { return used() == 0; } 124 125 private: 126 void reset_after_compaction() { set_top(compaction_top()); } 127 128 void clear(bool mangle_space); 129 130 HeapWord* block_start_const(const void* p) const; 131 132 void mangle_unused_area() PRODUCT_RETURN; 133 134 // Try to allocate at least min_word_size and up to desired_size from this region. 135 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 136 // space allocated. 137 // This version assumes that all allocation requests to this HeapRegion are properly 138 // synchronized. 139 inline HeapWord* allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 140 // Try to allocate at least min_word_size and up to desired_size from this HeapRegion. 141 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 142 // space allocated. 143 // This version synchronizes with other calls to par_allocate_impl(). 144 inline HeapWord* par_allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 145 146 public: 147 HeapWord* block_start(const void* p); 148 149 void object_iterate(ObjectClosure* blk); 150 151 // Allocation (return NULL if full). Assumes the caller has established 152 // mutually exclusive access to the HeapRegion. 153 HeapWord* allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 154 // Allocation (return NULL if full). Enforces mutual exclusion internally. 155 HeapWord* par_allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 156 157 HeapWord* allocate(size_t word_size); 158 HeapWord* par_allocate(size_t word_size); 159 160 inline HeapWord* par_allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* word_size); 161 inline HeapWord* allocate_no_bot_updates(size_t word_size); 162 inline HeapWord* allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* actual_size); 163 164 // Full GC support methods. 165 166 HeapWord* initialize_threshold(); 167 HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 168 // Update heap region to be consistent after Full GC compaction. 169 void reset_humongous_during_compaction() { 170 assert(is_humongous(), 171 "should only be called for humongous regions"); 172 173 zero_marked_bytes(); 174 init_top_at_mark_start(); 175 } 176 // Update heap region to be consistent after Full GC compaction. 177 void complete_compaction(); 178 179 // All allocated blocks are occupied by objects in a HeapRegion 180 bool block_is_obj(const HeapWord* p) const; 181 182 // Returns whether the given object is dead based on TAMS and bitmap. 183 bool is_obj_dead(const oop obj, const G1CMBitMap* const prev_bitmap) const; 184 185 // Returns the object size for all valid block starts 186 // and the amount of unallocated words if called on top() 187 size_t block_size(const HeapWord* p) const; 188 189 // Scans through the region using the bitmap to determine what 190 // objects to call size_t ApplyToMarkedClosure::apply(oop) for. 191 template<typename ApplyToMarkedClosure> 192 inline void apply_to_marked_objects(G1CMBitMap* bitmap, ApplyToMarkedClosure* closure); 193 194 void reset_bot() { 195 _bot_part.reset_bot(); 196 } 197 198 private: 199 // The remembered set for this region. 200 HeapRegionRemSet* _rem_set; 201 202 // Cached index of this region in the heap region sequence. 203 const uint _hrm_index; 204 205 HeapRegionType _type; 206 207 // For a humongous region, region in which it starts. 208 HeapRegion* _humongous_start_region; 209 210 // True iff an attempt to evacuate an object in the region failed. 211 bool _evacuation_failed; 212 213 static const uint InvalidCSetIndex = UINT_MAX; 214 215 // The index in the optional regions array, if this region 216 // is considered optional during a mixed collections. 217 uint _index_in_opt_cset; 218 219 // Fields used by the HeapRegionSetBase class and subclasses. 220 HeapRegion* _next; 221 HeapRegion* _prev; 222 #ifdef ASSERT 223 HeapRegionSetBase* _containing_set; 224 #endif // ASSERT 225 226 // The start of the unmarked area. The unmarked area extends from this 227 // word until the top and/or end of the region, and is the part 228 // of the region for which no marking was done, i.e. objects may 229 // have been allocated in this part since the last mark phase. 230 // "prev" is the top at the start of the last completed marking. 231 // "next" is the top at the start of the in-progress marking (if any.) 232 HeapWord* _prev_top_at_mark_start; 233 HeapWord* _next_top_at_mark_start; 234 235 // We use concurrent marking to determine the amount of live data 236 // in each heap region. 237 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 238 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 239 240 void init_top_at_mark_start() { 241 assert(_prev_marked_bytes == 0 && 242 _next_marked_bytes == 0, 243 "Must be called after zero_marked_bytes."); 244 _prev_top_at_mark_start = _next_top_at_mark_start = bottom(); 245 } 246 247 // Data for young region survivor prediction. 248 uint _young_index_in_cset; 249 SurvRateGroup* _surv_rate_group; 250 int _age_index; 251 252 // Cached attributes used in the collection set policy information 253 254 // The calculated GC efficiency of the region. 255 double _gc_efficiency; 256 257 // The remembered set length that was added to the total value 258 // for the collection set. 259 size_t _recorded_rs_length; 260 261 // The predicted elapsed time that was added to total value 262 // for the collection set. 263 double _predicted_elapsed_time_ms; 264 265 uint _node_index; 266 267 void report_region_type_change(G1HeapRegionTraceType::Type to); 268 269 // Returns whether the given object address refers to a dead object, and either the 270 // size of the object (if live) or the size of the block (if dead) in size. 271 // May 272 // - only called with obj < top() 273 // - not called on humongous objects or archive regions 274 inline bool is_obj_dead_with_size(const oop obj, const G1CMBitMap* const prev_bitmap, size_t* size) const; 275 276 // Iterate over the references covered by the given MemRegion in a humongous 277 // object and apply the given closure to them. 278 // Humongous objects are allocated directly in the old-gen. So we need special 279 // handling for concurrent processing encountering an in-progress allocation. 280 // Returns the address after the last actually scanned or NULL if the area could 281 // not be scanned (That should only happen when invoked concurrently with the 282 // mutator). 283 template <class Closure, bool is_gc_active> 284 inline HeapWord* do_oops_on_memregion_in_humongous(MemRegion mr, 285 Closure* cl, 286 G1CollectedHeap* g1h); 287 288 // Returns the block size of the given (dead, potentially having its class unloaded) object 289 // starting at p extending to at most the prev TAMS using the given mark bitmap. 290 inline size_t block_size_using_bitmap(const HeapWord* p, const G1CMBitMap* const prev_bitmap) const; 291 public: 292 HeapRegion(uint hrm_index, G1BlockOffsetTable* bot, MemRegion mr); 293 294 // If this region is a member of a HeapRegionManager, the index in that 295 // sequence, otherwise -1. 296 uint hrm_index() const { return _hrm_index; } 297 298 // Initializing the HeapRegion not only resets the data structure, but also 299 // resets the BOT for that heap region. 300 // The default values for clear_space means that we will do the clearing if 301 // there's clearing to be done ourselves. We also always mangle the space. 302 void initialize(bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 303 304 static int LogOfHRGrainBytes; 305 static int LogOfHRGrainWords; 306 static int LogCardsPerRegion; 307 308 static size_t GrainBytes; 309 static size_t GrainWords; 310 static size_t CardsPerRegion; 311 312 static size_t align_up_to_region_byte_size(size_t sz) { 313 return (sz + (size_t) GrainBytes - 1) & 314 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 315 } 316 317 // Returns whether a field is in the same region as the obj it points to. 318 template <typename T> 319 static bool is_in_same_region(T* p, oop obj) { 320 assert(p != NULL, "p can't be NULL"); 321 assert(obj != NULL, "obj can't be NULL"); 322 return (((uintptr_t) p ^ cast_from_oop<uintptr_t>(obj)) >> LogOfHRGrainBytes) == 0; 323 } 324 325 static size_t max_region_size(); 326 static size_t min_region_size_in_words(); 327 328 // It sets up the heap region size (GrainBytes / GrainWords), as 329 // well as other related fields that are based on the heap region 330 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 331 // CardsPerRegion). All those fields are considered constant 332 // throughout the JVM's execution, therefore they should only be set 333 // up once during initialization time. 334 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 335 336 // The number of bytes marked live in the region in the last marking phase. 337 size_t marked_bytes() { return _prev_marked_bytes; } 338 size_t live_bytes() { 339 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 340 } 341 342 // The number of bytes counted in the next marking. 343 size_t next_marked_bytes() { return _next_marked_bytes; } 344 // The number of bytes live wrt the next marking. 345 size_t next_live_bytes() { 346 return 347 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 348 } 349 350 // A lower bound on the amount of garbage bytes in the region. 351 size_t garbage_bytes() { 352 size_t used_at_mark_start_bytes = 353 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 354 return used_at_mark_start_bytes - marked_bytes(); 355 } 356 357 // Return the amount of bytes we'll reclaim if we collect this 358 // region. This includes not only the known garbage bytes in the 359 // region but also any unallocated space in it, i.e., [top, end), 360 // since it will also be reclaimed if we collect the region. 361 size_t reclaimable_bytes() { 362 size_t known_live_bytes = live_bytes(); 363 assert(known_live_bytes <= capacity(), "sanity"); 364 return capacity() - known_live_bytes; 365 } 366 367 // An upper bound on the number of live bytes in the region. 368 size_t max_live_bytes() { return used() - garbage_bytes(); } 369 370 void add_to_marked_bytes(size_t incr_bytes) { 371 _next_marked_bytes = _next_marked_bytes + incr_bytes; 372 } 373 374 void zero_marked_bytes() { 375 _prev_marked_bytes = _next_marked_bytes = 0; 376 } 377 // Get the start of the unmarked area in this region. 378 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 379 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 380 381 // Note the start or end of marking. This tells the heap region 382 // that the collector is about to start or has finished (concurrently) 383 // marking the heap. 384 385 // Notify the region that concurrent marking is starting. Initialize 386 // all fields related to the next marking info. 387 inline void note_start_of_marking(); 388 389 // Notify the region that concurrent marking has finished. Copy the 390 // (now finalized) next marking info fields into the prev marking 391 // info fields. 392 inline void note_end_of_marking(); 393 394 const char* get_type_str() const { return _type.get_str(); } 395 const char* get_short_type_str() const { return _type.get_short_str(); } 396 G1HeapRegionTraceType::Type get_trace_type() { return _type.get_trace_type(); } 397 398 bool is_free() const { return _type.is_free(); } 399 400 bool is_young() const { return _type.is_young(); } 401 bool is_eden() const { return _type.is_eden(); } 402 bool is_survivor() const { return _type.is_survivor(); } 403 404 bool is_humongous() const { return _type.is_humongous(); } 405 bool is_starts_humongous() const { return _type.is_starts_humongous(); } 406 bool is_continues_humongous() const { return _type.is_continues_humongous(); } 407 408 bool is_old() const { return _type.is_old(); } 409 410 bool is_old_or_humongous() const { return _type.is_old_or_humongous(); } 411 412 bool is_old_or_humongous_or_archive() const { return _type.is_old_or_humongous_or_archive(); } 413 414 // A pinned region contains objects which are not moved by garbage collections. 415 // Humongous regions and archive regions are pinned. 416 bool is_pinned() const { return _type.is_pinned(); } 417 418 // An archive region is a pinned region, also tagged as old, which 419 // should not be marked during mark/sweep. This allows the address 420 // space to be shared by JVM instances. 421 bool is_archive() const { return _type.is_archive(); } 422 bool is_open_archive() const { return _type.is_open_archive(); } 423 bool is_closed_archive() const { return _type.is_closed_archive(); } 424 425 void set_free(); 426 427 void set_eden(); 428 void set_eden_pre_gc(); 429 void set_survivor(); 430 431 void move_to_old(); 432 void set_old(); 433 434 void set_open_archive(); 435 void set_closed_archive(); 436 437 // For a humongous region, region in which it starts. 438 HeapRegion* humongous_start_region() const { 439 return _humongous_start_region; 440 } 441 442 // Makes the current region be a "starts humongous" region, i.e., 443 // the first region in a series of one or more contiguous regions 444 // that will contain a single "humongous" object. 445 // 446 // obj_top : points to the top of the humongous object. 447 // fill_size : size of the filler object at the end of the region series. 448 void set_starts_humongous(HeapWord* obj_top, size_t fill_size); 449 450 // Makes the current region be a "continues humongous' 451 // region. first_hr is the "start humongous" region of the series 452 // which this region will be part of. 453 void set_continues_humongous(HeapRegion* first_hr); 454 455 // Unsets the humongous-related fields on the region. 456 void clear_humongous(); 457 458 // If the region has a remembered set, return a pointer to it. 459 HeapRegionRemSet* rem_set() const { 460 return _rem_set; 461 } 462 463 inline bool in_collection_set() const; 464 465 // Methods used by the HeapRegionSetBase class and subclasses. 466 467 // Getter and setter for the next and prev fields used to link regions into 468 // linked lists. 469 void set_next(HeapRegion* next) { _next = next; } 470 HeapRegion* next() { return _next; } 471 472 void set_prev(HeapRegion* prev) { _prev = prev; } 473 HeapRegion* prev() { return _prev; } 474 475 // Every region added to a set is tagged with a reference to that 476 // set. This is used for doing consistency checking to make sure that 477 // the contents of a set are as they should be and it's only 478 // available in non-product builds. 479 #ifdef ASSERT 480 void set_containing_set(HeapRegionSetBase* containing_set) { 481 assert((containing_set == NULL && _containing_set != NULL) || 482 (containing_set != NULL && _containing_set == NULL), 483 "containing_set: " PTR_FORMAT " " 484 "_containing_set: " PTR_FORMAT, 485 p2i(containing_set), p2i(_containing_set)); 486 487 _containing_set = containing_set; 488 } 489 490 HeapRegionSetBase* containing_set() { return _containing_set; } 491 #else // ASSERT 492 void set_containing_set(HeapRegionSetBase* containing_set) { } 493 494 // containing_set() is only used in asserts so there's no reason 495 // to provide a dummy version of it. 496 #endif // ASSERT 497 498 499 // Reset the HeapRegion to default values. 500 // If skip_remset is true, do not clear the remembered set. 501 // If clear_space is true, clear the HeapRegion's memory. 502 // If locked is true, assume we are the only thread doing this operation. 503 void hr_clear(bool skip_remset, bool clear_space, bool locked = false); 504 // Clear the card table corresponding to this region. 505 void clear_cardtable(); 506 507 // Returns the "evacuation_failed" property of the region. 508 bool evacuation_failed() { return _evacuation_failed; } 509 510 // Sets the "evacuation_failed" property of the region. 511 void set_evacuation_failed(bool b) { 512 _evacuation_failed = b; 513 514 if (b) { 515 _next_marked_bytes = 0; 516 } 517 } 518 519 // Notify the region that we are about to start processing 520 // self-forwarded objects during evac failure handling. 521 void note_self_forwarding_removal_start(bool during_initial_mark, 522 bool during_conc_mark); 523 524 // Notify the region that we have finished processing self-forwarded 525 // objects during evac failure handling. 526 void note_self_forwarding_removal_end(size_t marked_bytes); 527 528 uint index_in_opt_cset() const { 529 assert(has_index_in_opt_cset(), "Opt cset index not set."); 530 return _index_in_opt_cset; 531 } 532 bool has_index_in_opt_cset() const { return _index_in_opt_cset != InvalidCSetIndex; } 533 void set_index_in_opt_cset(uint index) { _index_in_opt_cset = index; } 534 void clear_index_in_opt_cset() { _index_in_opt_cset = InvalidCSetIndex; } 535 536 void calc_gc_efficiency(void); 537 double gc_efficiency() const { return _gc_efficiency;} 538 539 uint young_index_in_cset() const { return _young_index_in_cset; } 540 void clear_young_index_in_cset() { _young_index_in_cset = 0; } 541 void set_young_index_in_cset(uint index) { 542 assert(index != UINT_MAX, "just checking"); 543 assert(index != 0, "just checking"); 544 assert(is_young(), "pre-condition"); 545 _young_index_in_cset = index; 546 } 547 548 int age_in_surv_rate_group() const; 549 bool has_valid_age_in_surv_rate() const; 550 551 bool has_surv_rate_group() const; 552 553 double surv_rate_prediction(G1Predictions const& predictor) const; 554 555 void install_surv_rate_group(SurvRateGroup* surv_rate_group); 556 void uninstall_surv_rate_group(); 557 558 void record_surv_words_in_group(size_t words_survived); 559 560 // Determine if an object has been allocated since the last 561 // mark performed by the collector. This returns true iff the object 562 // is within the unmarked area of the region. 563 bool obj_allocated_since_prev_marking(oop obj) const { 564 return (HeapWord *) obj >= prev_top_at_mark_start(); 565 } 566 bool obj_allocated_since_next_marking(oop obj) const { 567 return (HeapWord *) obj >= next_top_at_mark_start(); 568 } 569 570 // Iterate over the objects overlapping the given memory region, applying cl 571 // to all references in the region. This is a helper for 572 // G1RemSet::refine_card*, and is tightly coupled with them. 573 // mr must not be empty. Must be trimmed to the allocated/parseable space in this region. 574 // This region must be old or humongous. 575 // Returns the next unscanned address if the designated objects were successfully 576 // processed, NULL if an unparseable part of the heap was encountered (That should 577 // only happen when invoked concurrently with the mutator). 578 template <bool is_gc_active, class Closure> 579 inline HeapWord* oops_on_memregion_seq_iterate_careful(MemRegion mr, Closure* cl); 580 581 size_t recorded_rs_length() const { return _recorded_rs_length; } 582 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 583 584 void set_recorded_rs_length(size_t rs_length) { 585 _recorded_rs_length = rs_length; 586 } 587 588 void set_predicted_elapsed_time_ms(double ms) { 589 _predicted_elapsed_time_ms = ms; 590 } 591 592 // Routines for managing a list of code roots (attached to the 593 // this region's RSet) that point into this heap region. 594 void add_strong_code_root(nmethod* nm); 595 void add_strong_code_root_locked(nmethod* nm); 596 void remove_strong_code_root(nmethod* nm); 597 598 // Applies blk->do_code_blob() to each of the entries in 599 // the strong code roots list for this region 600 void strong_code_roots_do(CodeBlobClosure* blk) const; 601 602 uint node_index() const { return _node_index; } 603 void set_node_index(uint node_index) { _node_index = node_index; } 604 605 // Verify that the entries on the strong code root list for this 606 // region are live and include at least one pointer into this region. 607 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 608 609 void print() const; 610 void print_on(outputStream* st) const; 611 612 // vo == UsePrevMarking -> use "prev" marking information, 613 // vo == UseNextMarking -> use "next" marking information 614 // vo == UseFullMarking -> use "next" marking bitmap but no TAMS 615 // 616 // NOTE: Only the "prev" marking information is guaranteed to be 617 // consistent most of the time, so most calls to this should use 618 // vo == UsePrevMarking. 619 // Currently, there is only one case where this is called with 620 // vo == UseNextMarking, which is to verify the "next" marking 621 // information at the end of remark. 622 // Currently there is only one place where this is called with 623 // vo == UseFullMarking, which is to verify the marking during a 624 // full GC. 625 void verify(VerifyOption vo, bool *failures) const; 626 627 // Verify using the "prev" marking information 628 void verify() const; 629 630 void verify_rem_set(VerifyOption vo, bool *failures) const; 631 void verify_rem_set() const; 632 }; 633 634 // HeapRegionClosure is used for iterating over regions. 635 // Terminates the iteration when the "do_heap_region" method returns "true". 636 class HeapRegionClosure : public StackObj { 637 friend class HeapRegionManager; 638 friend class G1CollectionSet; 639 friend class G1CollectionSetCandidates; 640 641 bool _is_complete; 642 void set_incomplete() { _is_complete = false; } 643 644 public: 645 HeapRegionClosure(): _is_complete(true) {} 646 647 // Typically called on each region until it returns true. 648 virtual bool do_heap_region(HeapRegion* r) = 0; 649 650 // True after iteration if the closure was applied to all heap regions 651 // and returned "false" in all cases. 652 bool is_complete() { return _is_complete; } 653 }; 654 655 #endif // SHARE_GC_G1_HEAPREGION_HPP