1 /* 2 * Copyright (c) 2001, 2014, 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_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP 27 28 #include "gc_implementation/g1/g1BlockOffsetTable.hpp" 29 #include "gc_implementation/g1/g1_specialized_oop_closures.hpp" 30 #include "gc_implementation/g1/heapRegionType.hpp" 31 #include "gc_implementation/g1/survRateGroup.hpp" 32 #include "gc_implementation/shared/ageTable.hpp" 33 #include "gc_implementation/shared/spaceDecorator.hpp" 34 #include "memory/space.inline.hpp" 35 #include "memory/watermark.hpp" 36 #include "utilities/macros.hpp" 37 38 // A HeapRegion is the smallest piece of a G1CollectedHeap that 39 // can be collected independently. 40 41 // NOTE: Although a HeapRegion is a Space, its 42 // Space::initDirtyCardClosure method must not be called. 43 // The problem is that the existence of this method breaks 44 // the independence of barrier sets from remembered sets. 45 // The solution is to remove this method from the definition 46 // of a Space. 47 48 class HeapRegionRemSet; 49 class HeapRegionRemSetIterator; 50 class HeapRegion; 51 class HeapRegionSetBase; 52 class nmethod; 53 54 #define HR_FORMAT "%u:(%s)["PTR_FORMAT","PTR_FORMAT","PTR_FORMAT"]" 55 #define HR_FORMAT_PARAMS(_hr_) \ 56 (_hr_)->hrm_index(), \ 57 (_hr_)->get_short_type_str(), \ 58 p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end()) 59 60 // sentinel value for hrm_index 61 #define G1_NO_HRM_INDEX ((uint) -1) 62 63 // A dirty card to oop closure for heap regions. It 64 // knows how to get the G1 heap and how to use the bitmap 65 // in the concurrent marker used by G1 to filter remembered 66 // sets. 67 68 class HeapRegionDCTOC : public DirtyCardToOopClosure { 69 public: 70 // Specification of possible DirtyCardToOopClosure filtering. 71 enum FilterKind { 72 NoFilterKind, 73 IntoCSFilterKind, 74 OutOfRegionFilterKind 75 }; 76 77 protected: 78 HeapRegion* _hr; 79 FilterKind _fk; 80 G1CollectedHeap* _g1; 81 82 // Walk the given memory region from bottom to (actual) top 83 // looking for objects and applying the oop closure (_cl) to 84 // them. The base implementation of this treats the area as 85 // blocks, where a block may or may not be an object. Sub- 86 // classes should override this to provide more accurate 87 // or possibly more efficient walking. 88 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top); 89 90 public: 91 HeapRegionDCTOC(G1CollectedHeap* g1, 92 HeapRegion* hr, ExtendedOopClosure* cl, 93 CardTableModRefBS::PrecisionStyle precision, 94 FilterKind fk); 95 }; 96 97 // The complicating factor is that BlockOffsetTable diverged 98 // significantly, and we need functionality that is only in the G1 version. 99 // So I copied that code, which led to an alternate G1 version of 100 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could 101 // be reconciled, then G1OffsetTableContigSpace could go away. 102 103 // The idea behind time stamps is the following. Doing a save_marks on 104 // all regions at every GC pause is time consuming (if I remember 105 // well, 10ms or so). So, we would like to do that only for regions 106 // that are GC alloc regions. To achieve this, we use time 107 // stamps. For every evacuation pause, G1CollectedHeap generates a 108 // unique time stamp (essentially a counter that gets 109 // incremented). Every time we want to call save_marks on a region, 110 // we set the saved_mark_word to top and also copy the current GC 111 // time stamp to the time stamp field of the space. Reading the 112 // saved_mark_word involves checking the time stamp of the 113 // region. If it is the same as the current GC time stamp, then we 114 // can safely read the saved_mark_word field, as it is valid. If the 115 // time stamp of the region is not the same as the current GC time 116 // stamp, then we instead read top, as the saved_mark_word field is 117 // invalid. Time stamps (on the regions and also on the 118 // G1CollectedHeap) are reset at every cleanup (we iterate over 119 // the regions anyway) and at the end of a Full GC. The current scheme 120 // that uses sequential unsigned ints will fail only if we have 4b 121 // evacuation pauses between two cleanups, which is _highly_ unlikely. 122 class G1OffsetTableContigSpace: public CompactibleSpace { 123 friend class VMStructs; 124 HeapWord* _top; 125 protected: 126 G1BlockOffsetArrayContigSpace _offsets; 127 Mutex _par_alloc_lock; 128 volatile unsigned _gc_time_stamp; 129 // When we need to retire an allocation region, while other threads 130 // are also concurrently trying to allocate into it, we typically 131 // allocate a dummy object at the end of the region to ensure that 132 // no more allocations can take place in it. However, sometimes we 133 // want to know where the end of the last "real" object we allocated 134 // into the region was and this is what this keeps track. 135 HeapWord* _pre_dummy_top; 136 137 public: 138 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray, 139 MemRegion mr); 140 141 void set_top(HeapWord* value) { _top = value; } 142 HeapWord* top() const { return _top; } 143 144 protected: 145 // Reset the G1OffsetTableContigSpace. 146 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); 147 148 HeapWord** top_addr() { return &_top; } 149 // Allocation helpers (return NULL if full). 150 inline HeapWord* allocate_impl(size_t word_size, HeapWord* end_value); 151 inline HeapWord* par_allocate_impl(size_t word_size, HeapWord* end_value); 152 153 public: 154 void reset_after_compaction() { set_top(compaction_top()); } 155 156 size_t used() const { return byte_size(bottom(), top()); } 157 size_t free() const { return byte_size(top(), end()); } 158 bool is_free_block(const HeapWord* p) const { return p >= top(); } 159 160 MemRegion used_region() const { return MemRegion(bottom(), top()); } 161 162 void object_iterate(ObjectClosure* blk); 163 void safe_object_iterate(ObjectClosure* blk); 164 165 void set_bottom(HeapWord* value); 166 void set_end(HeapWord* value); 167 168 virtual HeapWord* saved_mark_word() const; 169 void record_top_and_timestamp(); 170 void reset_gc_time_stamp() { _gc_time_stamp = 0; } 171 unsigned get_gc_time_stamp() { return _gc_time_stamp; } 172 173 // See the comment above in the declaration of _pre_dummy_top for an 174 // explanation of what it is. 175 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 176 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 177 _pre_dummy_top = pre_dummy_top; 178 } 179 HeapWord* pre_dummy_top() { 180 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; 181 } 182 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 183 184 virtual void clear(bool mangle_space); 185 186 HeapWord* block_start(const void* p); 187 HeapWord* block_start_const(const void* p) const; 188 189 void prepare_for_compaction(CompactPoint* cp); 190 191 // Add offset table update. 192 virtual HeapWord* allocate(size_t word_size); 193 HeapWord* par_allocate(size_t word_size); 194 195 // MarkSweep support phase3 196 virtual HeapWord* initialize_threshold(); 197 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 198 199 virtual void print() const; 200 201 void reset_bot() { 202 _offsets.reset_bot(); 203 } 204 205 void print_bot_on(outputStream* out) { 206 _offsets.print_on(out); 207 } 208 }; 209 210 class HeapRegion: public G1OffsetTableContigSpace { 211 friend class VMStructs; 212 private: 213 214 // The remembered set for this region. 215 // (Might want to make this "inline" later, to avoid some alloc failure 216 // issues.) 217 HeapRegionRemSet* _rem_set; 218 219 G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; } 220 221 protected: 222 // The index of this region in the heap region sequence. 223 uint _hrm_index; 224 225 HeapRegionType _type; 226 227 // For a humongous region, region in which it starts. 228 HeapRegion* _humongous_start_region; 229 // For the start region of a humongous sequence, it's original end(). 230 HeapWord* _orig_end; 231 232 // True iff the region is in current collection_set. 233 bool _in_collection_set; 234 235 // True iff an attempt to evacuate an object in the region failed. 236 bool _evacuation_failed; 237 238 // A heap region may be a member one of a number of special subsets, each 239 // represented as linked lists through the field below. Currently, there 240 // is only one set: 241 // The collection set. 242 HeapRegion* _next_in_special_set; 243 244 // next region in the young "generation" region set 245 HeapRegion* _next_young_region; 246 247 // Next region whose cards need cleaning 248 HeapRegion* _next_dirty_cards_region; 249 250 // Fields used by the HeapRegionSetBase class and subclasses. 251 HeapRegion* _next; 252 HeapRegion* _prev; 253 #ifdef ASSERT 254 HeapRegionSetBase* _containing_set; 255 #endif // ASSERT 256 257 // For parallel heapRegion traversal. 258 jint _claimed; 259 260 // We use concurrent marking to determine the amount of live data 261 // in each heap region. 262 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 263 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 264 265 // The calculated GC efficiency of the region. 266 double _gc_efficiency; 267 268 int _young_index_in_cset; 269 SurvRateGroup* _surv_rate_group; 270 int _age_index; 271 272 // The start of the unmarked area. The unmarked area extends from this 273 // word until the top and/or end of the region, and is the part 274 // of the region for which no marking was done, i.e. objects may 275 // have been allocated in this part since the last mark phase. 276 // "prev" is the top at the start of the last completed marking. 277 // "next" is the top at the start of the in-progress marking (if any.) 278 HeapWord* _prev_top_at_mark_start; 279 HeapWord* _next_top_at_mark_start; 280 // If a collection pause is in progress, this is the top at the start 281 // of that pause. 282 283 void init_top_at_mark_start() { 284 assert(_prev_marked_bytes == 0 && 285 _next_marked_bytes == 0, 286 "Must be called after zero_marked_bytes."); 287 HeapWord* bot = bottom(); 288 _prev_top_at_mark_start = bot; 289 _next_top_at_mark_start = bot; 290 } 291 292 // Cached attributes used in the collection set policy information 293 294 // The RSet length that was added to the total value 295 // for the collection set. 296 size_t _recorded_rs_length; 297 298 // The predicted elapsed time that was added to total value 299 // for the collection set. 300 double _predicted_elapsed_time_ms; 301 302 // The predicted number of bytes to copy that was added to 303 // the total value for the collection set. 304 size_t _predicted_bytes_to_copy; 305 306 public: 307 HeapRegion(uint hrm_index, 308 G1BlockOffsetSharedArray* sharedOffsetArray, 309 MemRegion mr); 310 311 // Initializing the HeapRegion not only resets the data structure, but also 312 // resets the BOT for that heap region. 313 // The default values for clear_space means that we will do the clearing if 314 // there's clearing to be done ourselves. We also always mangle the space. 315 virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 316 317 static int LogOfHRGrainBytes; 318 static int LogOfHRGrainWords; 319 320 static size_t GrainBytes; 321 static size_t GrainWords; 322 static size_t CardsPerRegion; 323 324 static size_t align_up_to_region_byte_size(size_t sz) { 325 return (sz + (size_t) GrainBytes - 1) & 326 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 327 } 328 329 static size_t max_region_size(); 330 331 // It sets up the heap region size (GrainBytes / GrainWords), as 332 // well as other related fields that are based on the heap region 333 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 334 // CardsPerRegion). All those fields are considered constant 335 // throughout the JVM's execution, therefore they should only be set 336 // up once during initialization time. 337 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 338 339 enum ClaimValues { 340 InitialClaimValue = 0, 341 FinalCountClaimValue = 1, 342 NoteEndClaimValue = 2, 343 ScrubRemSetClaimValue = 3, 344 ParVerifyClaimValue = 4, 345 RebuildRSClaimValue = 5, 346 ParEvacFailureClaimValue = 6, 347 AggregateCountClaimValue = 7, 348 VerifyCountClaimValue = 8, 349 ParMarkRootClaimValue = 9 350 }; 351 352 // All allocated blocks are occupied by objects in a HeapRegion 353 bool block_is_obj(const HeapWord* p) const; 354 355 // Returns the object size for all valid block starts 356 // and the amount of unallocated words if called on top() 357 size_t block_size(const HeapWord* p) const; 358 359 inline HeapWord* par_allocate_no_bot_updates(size_t word_size); 360 inline HeapWord* allocate_no_bot_updates(size_t word_size); 361 362 // If this region is a member of a HeapRegionManager, the index in that 363 // sequence, otherwise -1. 364 uint hrm_index() const { return _hrm_index; } 365 366 // The number of bytes marked live in the region in the last marking phase. 367 size_t marked_bytes() { return _prev_marked_bytes; } 368 size_t live_bytes() { 369 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 370 } 371 372 // The number of bytes counted in the next marking. 373 size_t next_marked_bytes() { return _next_marked_bytes; } 374 // The number of bytes live wrt the next marking. 375 size_t next_live_bytes() { 376 return 377 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 378 } 379 380 // A lower bound on the amount of garbage bytes in the region. 381 size_t garbage_bytes() { 382 size_t used_at_mark_start_bytes = 383 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 384 assert(used_at_mark_start_bytes >= marked_bytes(), 385 "Can't mark more than we have."); 386 return used_at_mark_start_bytes - marked_bytes(); 387 } 388 389 // Return the amount of bytes we'll reclaim if we collect this 390 // region. This includes not only the known garbage bytes in the 391 // region but also any unallocated space in it, i.e., [top, end), 392 // since it will also be reclaimed if we collect the region. 393 size_t reclaimable_bytes() { 394 size_t known_live_bytes = live_bytes(); 395 assert(known_live_bytes <= capacity(), "sanity"); 396 return capacity() - known_live_bytes; 397 } 398 399 // An upper bound on the number of live bytes in the region. 400 size_t max_live_bytes() { return used() - garbage_bytes(); } 401 402 void add_to_marked_bytes(size_t incr_bytes) { 403 _next_marked_bytes = _next_marked_bytes + incr_bytes; 404 assert(_next_marked_bytes <= used(), "invariant" ); 405 } 406 407 void zero_marked_bytes() { 408 _prev_marked_bytes = _next_marked_bytes = 0; 409 } 410 411 const char* get_type_str() const { return _type.get_str(); } 412 const char* get_short_type_str() const { return _type.get_short_str(); } 413 414 bool is_free() const { return _type.is_free(); } 415 416 bool is_young() const { return _type.is_young(); } 417 bool is_eden() const { return _type.is_eden(); } 418 bool is_survivor() const { return _type.is_survivor(); } 419 420 bool isHumongous() const { return _type.is_humongous(); } 421 bool startsHumongous() const { return _type.is_starts_humongous(); } 422 bool continuesHumongous() const { return _type.is_continues_humongous(); } 423 424 bool is_old() const { return _type.is_old(); } 425 426 // For a humongous region, region in which it starts. 427 HeapRegion* humongous_start_region() const { 428 return _humongous_start_region; 429 } 430 431 // Return the number of distinct regions that are covered by this region: 432 // 1 if the region is not humongous, >= 1 if the region is humongous. 433 uint region_num() const { 434 if (!isHumongous()) { 435 return 1U; 436 } else { 437 assert(startsHumongous(), "doesn't make sense on HC regions"); 438 assert(capacity() % HeapRegion::GrainBytes == 0, "sanity"); 439 return (uint) (capacity() >> HeapRegion::LogOfHRGrainBytes); 440 } 441 } 442 443 // Return the index + 1 of the last HC regions that's associated 444 // with this HS region. 445 uint last_hc_index() const { 446 assert(startsHumongous(), "don't call this otherwise"); 447 return hrm_index() + region_num(); 448 } 449 450 // Same as Space::is_in_reserved, but will use the original size of the region. 451 // The original size is different only for start humongous regions. They get 452 // their _end set up to be the end of the last continues region of the 453 // corresponding humongous object. 454 bool is_in_reserved_raw(const void* p) const { 455 return _bottom <= p && p < _orig_end; 456 } 457 458 // Makes the current region be a "starts humongous" region, i.e., 459 // the first region in a series of one or more contiguous regions 460 // that will contain a single "humongous" object. The two parameters 461 // are as follows: 462 // 463 // new_top : The new value of the top field of this region which 464 // points to the end of the humongous object that's being 465 // allocated. If there is more than one region in the series, top 466 // will lie beyond this region's original end field and on the last 467 // region in the series. 468 // 469 // new_end : The new value of the end field of this region which 470 // points to the end of the last region in the series. If there is 471 // one region in the series (namely: this one) end will be the same 472 // as the original end of this region. 473 // 474 // Updating top and end as described above makes this region look as 475 // if it spans the entire space taken up by all the regions in the 476 // series and an single allocation moved its top to new_top. This 477 // ensures that the space (capacity / allocated) taken up by all 478 // humongous regions can be calculated by just looking at the 479 // "starts humongous" regions and by ignoring the "continues 480 // humongous" regions. 481 void set_startsHumongous(HeapWord* new_top, HeapWord* new_end); 482 483 // Makes the current region be a "continues humongous' 484 // region. first_hr is the "start humongous" region of the series 485 // which this region will be part of. 486 void set_continuesHumongous(HeapRegion* first_hr); 487 488 // Unsets the humongous-related fields on the region. 489 void clear_humongous(); 490 491 // If the region has a remembered set, return a pointer to it. 492 HeapRegionRemSet* rem_set() const { 493 return _rem_set; 494 } 495 496 // True iff the region is in current collection_set. 497 bool in_collection_set() const { 498 return _in_collection_set; 499 } 500 void set_in_collection_set(bool b) { 501 _in_collection_set = b; 502 } 503 HeapRegion* next_in_collection_set() { 504 assert(in_collection_set(), "should only invoke on member of CS."); 505 assert(_next_in_special_set == NULL || 506 _next_in_special_set->in_collection_set(), 507 "Malformed CS."); 508 return _next_in_special_set; 509 } 510 void set_next_in_collection_set(HeapRegion* r) { 511 assert(in_collection_set(), "should only invoke on member of CS."); 512 assert(r == NULL || r->in_collection_set(), "Malformed CS."); 513 _next_in_special_set = r; 514 } 515 516 // Methods used by the HeapRegionSetBase class and subclasses. 517 518 // Getter and setter for the next and prev fields used to link regions into 519 // linked lists. 520 HeapRegion* next() { return _next; } 521 HeapRegion* prev() { return _prev; } 522 523 void set_next(HeapRegion* next) { _next = next; } 524 void set_prev(HeapRegion* prev) { _prev = prev; } 525 526 // Every region added to a set is tagged with a reference to that 527 // set. This is used for doing consistency checking to make sure that 528 // the contents of a set are as they should be and it's only 529 // available in non-product builds. 530 #ifdef ASSERT 531 void set_containing_set(HeapRegionSetBase* containing_set) { 532 assert((containing_set == NULL && _containing_set != NULL) || 533 (containing_set != NULL && _containing_set == NULL), 534 err_msg("containing_set: "PTR_FORMAT" " 535 "_containing_set: "PTR_FORMAT, 536 p2i(containing_set), p2i(_containing_set))); 537 538 _containing_set = containing_set; 539 } 540 541 HeapRegionSetBase* containing_set() { return _containing_set; } 542 #else // ASSERT 543 void set_containing_set(HeapRegionSetBase* containing_set) { } 544 545 // containing_set() is only used in asserts so there's no reason 546 // to provide a dummy version of it. 547 #endif // ASSERT 548 549 HeapRegion* get_next_young_region() { return _next_young_region; } 550 void set_next_young_region(HeapRegion* hr) { 551 _next_young_region = hr; 552 } 553 554 HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; } 555 HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; } 556 void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; } 557 bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; } 558 559 HeapWord* orig_end() const { return _orig_end; } 560 561 // Reset HR stuff to default values. 562 void hr_clear(bool par, bool clear_space, bool locked = false); 563 void par_clear(); 564 565 // Get the start of the unmarked area in this region. 566 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 567 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 568 569 // Note the start or end of marking. This tells the heap region 570 // that the collector is about to start or has finished (concurrently) 571 // marking the heap. 572 573 // Notify the region that concurrent marking is starting. Initialize 574 // all fields related to the next marking info. 575 inline void note_start_of_marking(); 576 577 // Notify the region that concurrent marking has finished. Copy the 578 // (now finalized) next marking info fields into the prev marking 579 // info fields. 580 inline void note_end_of_marking(); 581 582 // Notify the region that it will be used as to-space during a GC 583 // and we are about to start copying objects into it. 584 inline void note_start_of_copying(bool during_initial_mark); 585 586 // Notify the region that it ceases being to-space during a GC and 587 // we will not copy objects into it any more. 588 inline void note_end_of_copying(bool during_initial_mark); 589 590 // Notify the region that we are about to start processing 591 // self-forwarded objects during evac failure handling. 592 void note_self_forwarding_removal_start(bool during_initial_mark, 593 bool during_conc_mark); 594 595 // Notify the region that we have finished processing self-forwarded 596 // objects during evac failure handling. 597 void note_self_forwarding_removal_end(bool during_initial_mark, 598 bool during_conc_mark, 599 size_t marked_bytes); 600 601 // Returns "false" iff no object in the region was allocated when the 602 // last mark phase ended. 603 bool is_marked() { return _prev_top_at_mark_start != bottom(); } 604 605 void reset_during_compaction() { 606 assert(isHumongous() && startsHumongous(), 607 "should only be called for starts humongous regions"); 608 609 zero_marked_bytes(); 610 init_top_at_mark_start(); 611 } 612 613 void calc_gc_efficiency(void); 614 double gc_efficiency() { return _gc_efficiency;} 615 616 int young_index_in_cset() const { return _young_index_in_cset; } 617 void set_young_index_in_cset(int index) { 618 assert( (index == -1) || is_young(), "pre-condition" ); 619 _young_index_in_cset = index; 620 } 621 622 int age_in_surv_rate_group() { 623 assert( _surv_rate_group != NULL, "pre-condition" ); 624 assert( _age_index > -1, "pre-condition" ); 625 return _surv_rate_group->age_in_group(_age_index); 626 } 627 628 void record_surv_words_in_group(size_t words_survived) { 629 assert( _surv_rate_group != NULL, "pre-condition" ); 630 assert( _age_index > -1, "pre-condition" ); 631 int age_in_group = age_in_surv_rate_group(); 632 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 633 } 634 635 int age_in_surv_rate_group_cond() { 636 if (_surv_rate_group != NULL) 637 return age_in_surv_rate_group(); 638 else 639 return -1; 640 } 641 642 SurvRateGroup* surv_rate_group() { 643 return _surv_rate_group; 644 } 645 646 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 647 assert( surv_rate_group != NULL, "pre-condition" ); 648 assert( _surv_rate_group == NULL, "pre-condition" ); 649 assert( is_young(), "pre-condition" ); 650 651 _surv_rate_group = surv_rate_group; 652 _age_index = surv_rate_group->next_age_index(); 653 } 654 655 void uninstall_surv_rate_group() { 656 if (_surv_rate_group != NULL) { 657 assert( _age_index > -1, "pre-condition" ); 658 assert( is_young(), "pre-condition" ); 659 660 _surv_rate_group = NULL; 661 _age_index = -1; 662 } else { 663 assert( _age_index == -1, "pre-condition" ); 664 } 665 } 666 667 void set_free() { _type.set_free(); } 668 669 void set_eden() { _type.set_eden(); } 670 void set_eden_pre_gc() { _type.set_eden_pre_gc(); } 671 void set_survivor() { _type.set_survivor(); } 672 673 void set_old() { _type.set_old(); } 674 675 // Determine if an object has been allocated since the last 676 // mark performed by the collector. This returns true iff the object 677 // is within the unmarked area of the region. 678 bool obj_allocated_since_prev_marking(oop obj) const { 679 return (HeapWord *) obj >= prev_top_at_mark_start(); 680 } 681 bool obj_allocated_since_next_marking(oop obj) const { 682 return (HeapWord *) obj >= next_top_at_mark_start(); 683 } 684 685 // For parallel heapRegion traversal. 686 bool claimHeapRegion(int claimValue); 687 jint claim_value() { return _claimed; } 688 // Use this carefully: only when you're sure no one is claiming... 689 void set_claim_value(int claimValue) { _claimed = claimValue; } 690 691 // Returns the "evacuation_failed" property of the region. 692 bool evacuation_failed() { return _evacuation_failed; } 693 694 // Sets the "evacuation_failed" property of the region. 695 void set_evacuation_failed(bool b) { 696 _evacuation_failed = b; 697 698 if (b) { 699 _next_marked_bytes = 0; 700 } 701 } 702 703 // Requires that "mr" be entirely within the region. 704 // Apply "cl->do_object" to all objects that intersect with "mr". 705 // If the iteration encounters an unparseable portion of the region, 706 // or if "cl->abort()" is true after a closure application, 707 // terminate the iteration and return the address of the start of the 708 // subregion that isn't done. (The two can be distinguished by querying 709 // "cl->abort()".) Return of "NULL" indicates that the iteration 710 // completed. 711 HeapWord* 712 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl); 713 714 // filter_young: if true and the region is a young region then we 715 // skip the iteration. 716 // card_ptr: if not NULL, and we decide that the card is not young 717 // and we iterate over it, we'll clean the card before we start the 718 // iteration. 719 HeapWord* 720 oops_on_card_seq_iterate_careful(MemRegion mr, 721 FilterOutOfRegionClosure* cl, 722 bool filter_young, 723 jbyte* card_ptr); 724 725 size_t recorded_rs_length() const { return _recorded_rs_length; } 726 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 727 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; } 728 729 void set_recorded_rs_length(size_t rs_length) { 730 _recorded_rs_length = rs_length; 731 } 732 733 void set_predicted_elapsed_time_ms(double ms) { 734 _predicted_elapsed_time_ms = ms; 735 } 736 737 void set_predicted_bytes_to_copy(size_t bytes) { 738 _predicted_bytes_to_copy = bytes; 739 } 740 741 virtual CompactibleSpace* next_compaction_space() const; 742 743 virtual void reset_after_compaction(); 744 745 // Routines for managing a list of code roots (attached to the 746 // this region's RSet) that point into this heap region. 747 void add_strong_code_root(nmethod* nm); 748 void add_strong_code_root_locked(nmethod* nm); 749 void remove_strong_code_root(nmethod* nm); 750 751 // Applies blk->do_code_blob() to each of the entries in 752 // the strong code roots list for this region 753 void strong_code_roots_do(CodeBlobClosure* blk) const; 754 755 // Verify that the entries on the strong code root list for this 756 // region are live and include at least one pointer into this region. 757 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 758 759 void print() const; 760 void print_on(outputStream* st) const; 761 762 // vo == UsePrevMarking -> use "prev" marking information, 763 // vo == UseNextMarking -> use "next" marking information 764 // vo == UseMarkWord -> use the mark word in the object header 765 // 766 // NOTE: Only the "prev" marking information is guaranteed to be 767 // consistent most of the time, so most calls to this should use 768 // vo == UsePrevMarking. 769 // Currently, there is only one case where this is called with 770 // vo == UseNextMarking, which is to verify the "next" marking 771 // information at the end of remark. 772 // Currently there is only one place where this is called with 773 // vo == UseMarkWord, which is to verify the marking during a 774 // full GC. 775 void verify(VerifyOption vo, bool *failures) const; 776 777 // Override; it uses the "prev" marking information 778 virtual void verify() const; 779 }; 780 781 // HeapRegionClosure is used for iterating over regions. 782 // Terminates the iteration when the "doHeapRegion" method returns "true". 783 class HeapRegionClosure : public StackObj { 784 friend class HeapRegionManager; 785 friend class G1CollectedHeap; 786 787 bool _complete; 788 void incomplete() { _complete = false; } 789 790 public: 791 HeapRegionClosure(): _complete(true) {} 792 793 // Typically called on each region until it returns true. 794 virtual bool doHeapRegion(HeapRegion* r) = 0; 795 796 // True after iteration if the closure was applied to all heap regions 797 // and returned "false" in all cases. 798 bool complete() { return _complete; } 799 }; 800 801 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP