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 // Add offset table update. 190 virtual HeapWord* allocate(size_t word_size); 191 HeapWord* par_allocate(size_t word_size); 192 193 // MarkSweep support phase3 194 virtual HeapWord* initialize_threshold(); 195 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 196 197 virtual void print() const; 198 199 void reset_bot() { 200 _offsets.reset_bot(); 201 } 202 203 void print_bot_on(outputStream* out) { 204 _offsets.print_on(out); 205 } 206 }; 207 208 class HeapRegion: public G1OffsetTableContigSpace { 209 friend class VMStructs; 210 private: 211 212 // The remembered set for this region. 213 // (Might want to make this "inline" later, to avoid some alloc failure 214 // issues.) 215 HeapRegionRemSet* _rem_set; 216 217 G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; } 218 219 protected: 220 // The index of this region in the heap region sequence. 221 uint _hrm_index; 222 223 HeapRegionType _type; 224 225 // For a humongous region, region in which it starts. 226 HeapRegion* _humongous_start_region; 227 // True iff the region is in current collection_set. 228 bool _in_collection_set; 229 230 // True iff an attempt to evacuate an object in the region failed. 231 bool _evacuation_failed; 232 233 // A heap region may be a member one of a number of special subsets, each 234 // represented as linked lists through the field below. Currently, there 235 // is only one set: 236 // The collection set. 237 HeapRegion* _next_in_special_set; 238 239 // next region in the young "generation" region set 240 HeapRegion* _next_young_region; 241 242 // Next region whose cards need cleaning 243 HeapRegion* _next_dirty_cards_region; 244 245 // Fields used by the HeapRegionSetBase class and subclasses. 246 HeapRegion* _next; 247 HeapRegion* _prev; 248 #ifdef ASSERT 249 HeapRegionSetBase* _containing_set; 250 #endif // ASSERT 251 252 // For parallel heapRegion traversal. 253 jint _claimed; 254 255 // We use concurrent marking to determine the amount of live data 256 // in each heap region. 257 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 258 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 259 260 // The calculated GC efficiency of the region. 261 double _gc_efficiency; 262 263 int _young_index_in_cset; 264 SurvRateGroup* _surv_rate_group; 265 int _age_index; 266 267 // The start of the unmarked area. The unmarked area extends from this 268 // word until the top and/or end of the region, and is the part 269 // of the region for which no marking was done, i.e. objects may 270 // have been allocated in this part since the last mark phase. 271 // "prev" is the top at the start of the last completed marking. 272 // "next" is the top at the start of the in-progress marking (if any.) 273 HeapWord* _prev_top_at_mark_start; 274 HeapWord* _next_top_at_mark_start; 275 // If a collection pause is in progress, this is the top at the start 276 // of that pause. 277 278 void init_top_at_mark_start() { 279 assert(_prev_marked_bytes == 0 && 280 _next_marked_bytes == 0, 281 "Must be called after zero_marked_bytes."); 282 HeapWord* bot = bottom(); 283 _prev_top_at_mark_start = bot; 284 _next_top_at_mark_start = bot; 285 } 286 287 // Cached attributes used in the collection set policy information 288 289 // The RSet length that was added to the total value 290 // for the collection set. 291 size_t _recorded_rs_length; 292 293 // The predicted elapsed time that was added to total value 294 // for the collection set. 295 double _predicted_elapsed_time_ms; 296 297 // The predicted number of bytes to copy that was added to 298 // the total value for the collection set. 299 size_t _predicted_bytes_to_copy; 300 301 public: 302 HeapRegion(uint hrm_index, 303 G1BlockOffsetSharedArray* sharedOffsetArray, 304 MemRegion mr); 305 306 // Initializing the HeapRegion not only resets the data structure, but also 307 // resets the BOT for that heap region. 308 // The default values for clear_space means that we will do the clearing if 309 // there's clearing to be done ourselves. We also always mangle the space. 310 virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 311 312 static int LogOfHRGrainBytes; 313 static int LogOfHRGrainWords; 314 315 static size_t GrainBytes; 316 static size_t GrainWords; 317 static size_t CardsPerRegion; 318 319 static size_t align_up_to_region_byte_size(size_t sz) { 320 return (sz + (size_t) GrainBytes - 1) & 321 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 322 } 323 324 static size_t max_region_size(); 325 326 // It sets up the heap region size (GrainBytes / GrainWords), as 327 // well as other related fields that are based on the heap region 328 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 329 // CardsPerRegion). All those fields are considered constant 330 // throughout the JVM's execution, therefore they should only be set 331 // up once during initialization time. 332 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 333 334 enum ClaimValues { 335 InitialClaimValue = 0, 336 FinalCountClaimValue = 1, 337 NoteEndClaimValue = 2, 338 ScrubRemSetClaimValue = 3, 339 ParVerifyClaimValue = 4, 340 RebuildRSClaimValue = 5, 341 ParEvacFailureClaimValue = 6, 342 AggregateCountClaimValue = 7, 343 VerifyCountClaimValue = 8, 344 ParMarkRootClaimValue = 9 345 }; 346 347 // All allocated blocks are occupied by objects in a HeapRegion 348 bool block_is_obj(const HeapWord* p) const; 349 350 // Returns the object size for all valid block starts 351 // and the amount of unallocated words if called on top() 352 size_t block_size(const HeapWord* p) const; 353 354 // Functions for scan_and_forward support. 355 void prepare_for_compaction(CompactPoint* cp); 356 357 inline HeapWord* scan_limit() const { 358 return top(); 359 } 360 361 inline bool scanned_block_is_obj(const HeapWord* addr) const { 362 return true; // Always true, since scan_limit is top 363 } 364 365 inline size_t scanned_block_size(const HeapWord* addr) const { 366 return HeapRegion::block_size(addr); // Avoid virtual call 367 } 368 369 inline HeapWord* par_allocate_no_bot_updates(size_t word_size); 370 inline HeapWord* allocate_no_bot_updates(size_t word_size); 371 372 // If this region is a member of a HeapRegionManager, the index in that 373 // sequence, otherwise -1. 374 uint hrm_index() const { return _hrm_index; } 375 376 // The number of bytes marked live in the region in the last marking phase. 377 size_t marked_bytes() { return _prev_marked_bytes; } 378 size_t live_bytes() { 379 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 380 } 381 382 // The number of bytes counted in the next marking. 383 size_t next_marked_bytes() { return _next_marked_bytes; } 384 // The number of bytes live wrt the next marking. 385 size_t next_live_bytes() { 386 return 387 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 388 } 389 390 // A lower bound on the amount of garbage bytes in the region. 391 size_t garbage_bytes() { 392 size_t used_at_mark_start_bytes = 393 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 394 assert(used_at_mark_start_bytes >= marked_bytes(), 395 "Can't mark more than we have."); 396 return used_at_mark_start_bytes - marked_bytes(); 397 } 398 399 // Return the amount of bytes we'll reclaim if we collect this 400 // region. This includes not only the known garbage bytes in the 401 // region but also any unallocated space in it, i.e., [top, end), 402 // since it will also be reclaimed if we collect the region. 403 size_t reclaimable_bytes() { 404 size_t known_live_bytes = live_bytes(); 405 assert(known_live_bytes <= capacity(), "sanity"); 406 return capacity() - known_live_bytes; 407 } 408 409 // An upper bound on the number of live bytes in the region. 410 size_t max_live_bytes() { return used() - garbage_bytes(); } 411 412 void add_to_marked_bytes(size_t incr_bytes) { 413 _next_marked_bytes = _next_marked_bytes + incr_bytes; 414 assert(_next_marked_bytes <= used(), "invariant" ); 415 } 416 417 void zero_marked_bytes() { 418 _prev_marked_bytes = _next_marked_bytes = 0; 419 } 420 421 const char* get_type_str() const { return _type.get_str(); } 422 const char* get_short_type_str() const { return _type.get_short_str(); } 423 424 bool is_free() const { return _type.is_free(); } 425 426 bool is_young() const { return _type.is_young(); } 427 bool is_eden() const { return _type.is_eden(); } 428 bool is_survivor() const { return _type.is_survivor(); } 429 430 bool isHumongous() const { return _type.is_humongous(); } 431 bool startsHumongous() const { return _type.is_starts_humongous(); } 432 bool continuesHumongous() const { return _type.is_continues_humongous(); } 433 434 bool is_old() const { return _type.is_old(); } 435 436 // For a humongous region, region in which it starts. 437 HeapRegion* humongous_start_region() const { 438 return _humongous_start_region; 439 } 440 441 // Return the number of distinct regions that are covered by this region: 442 // 1 if the region is not humongous, >= 1 if the region is humongous. 443 uint region_num() const { 444 if (!isHumongous()) { 445 return 1U; 446 } else { 447 assert(startsHumongous(), "doesn't make sense on HC regions"); 448 assert(capacity() % HeapRegion::GrainBytes == 0, "sanity"); 449 return (uint) (capacity() >> HeapRegion::LogOfHRGrainBytes); 450 } 451 } 452 453 // Return the index + 1 of the last HC regions that's associated 454 // with this HS region. 455 uint last_hc_index() const { 456 assert(startsHumongous(), "don't call this otherwise"); 457 return hrm_index() + region_num(); 458 } 459 460 // Same as Space::is_in_reserved, but will use the original size of the region. 461 // The original size is different only for start humongous regions. They get 462 // their _end set up to be the end of the last continues region of the 463 // corresponding humongous object. 464 bool is_in_reserved_raw(const void* p) const { 465 return _bottom <= p && p < orig_end(); 466 } 467 468 // Makes the current region be a "starts humongous" region, i.e., 469 // the first region in a series of one or more contiguous regions 470 // that will contain a single "humongous" object. The two parameters 471 // are as follows: 472 // 473 // new_top : The new value of the top field of this region which 474 // points to the end of the humongous object that's being 475 // allocated. If there is more than one region in the series, top 476 // will lie beyond this region's original end field and on the last 477 // region in the series. 478 // 479 // new_end : The new value of the end field of this region which 480 // points to the end of the last region in the series. If there is 481 // one region in the series (namely: this one) end will be the same 482 // as the original end of this region. 483 // 484 // Updating top and end as described above makes this region look as 485 // if it spans the entire space taken up by all the regions in the 486 // series and an single allocation moved its top to new_top. This 487 // ensures that the space (capacity / allocated) taken up by all 488 // humongous regions can be calculated by just looking at the 489 // "starts humongous" regions and by ignoring the "continues 490 // humongous" regions. 491 void set_startsHumongous(HeapWord* new_top, HeapWord* new_end); 492 493 // Makes the current region be a "continues humongous' 494 // region. first_hr is the "start humongous" region of the series 495 // which this region will be part of. 496 void set_continuesHumongous(HeapRegion* first_hr); 497 498 // Unsets the humongous-related fields on the region. 499 void clear_humongous(); 500 501 // If the region has a remembered set, return a pointer to it. 502 HeapRegionRemSet* rem_set() const { 503 return _rem_set; 504 } 505 506 // True iff the region is in current collection_set. 507 bool in_collection_set() const { 508 return _in_collection_set; 509 } 510 void set_in_collection_set(bool b) { 511 _in_collection_set = b; 512 } 513 HeapRegion* next_in_collection_set() { 514 assert(in_collection_set(), "should only invoke on member of CS."); 515 assert(_next_in_special_set == NULL || 516 _next_in_special_set->in_collection_set(), 517 "Malformed CS."); 518 return _next_in_special_set; 519 } 520 void set_next_in_collection_set(HeapRegion* r) { 521 assert(in_collection_set(), "should only invoke on member of CS."); 522 assert(r == NULL || r->in_collection_set(), "Malformed CS."); 523 _next_in_special_set = r; 524 } 525 526 // Methods used by the HeapRegionSetBase class and subclasses. 527 528 // Getter and setter for the next and prev fields used to link regions into 529 // linked lists. 530 HeapRegion* next() { return _next; } 531 HeapRegion* prev() { return _prev; } 532 533 void set_next(HeapRegion* next) { _next = next; } 534 void set_prev(HeapRegion* prev) { _prev = prev; } 535 536 // Every region added to a set is tagged with a reference to that 537 // set. This is used for doing consistency checking to make sure that 538 // the contents of a set are as they should be and it's only 539 // available in non-product builds. 540 #ifdef ASSERT 541 void set_containing_set(HeapRegionSetBase* containing_set) { 542 assert((containing_set == NULL && _containing_set != NULL) || 543 (containing_set != NULL && _containing_set == NULL), 544 err_msg("containing_set: "PTR_FORMAT" " 545 "_containing_set: "PTR_FORMAT, 546 p2i(containing_set), p2i(_containing_set))); 547 548 _containing_set = containing_set; 549 } 550 551 HeapRegionSetBase* containing_set() { return _containing_set; } 552 #else // ASSERT 553 void set_containing_set(HeapRegionSetBase* containing_set) { } 554 555 // containing_set() is only used in asserts so there's no reason 556 // to provide a dummy version of it. 557 #endif // ASSERT 558 559 HeapRegion* get_next_young_region() { return _next_young_region; } 560 void set_next_young_region(HeapRegion* hr) { 561 _next_young_region = hr; 562 } 563 564 HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; } 565 HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; } 566 void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; } 567 bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; } 568 569 // For the start region of a humongous sequence, it's original end(). 570 HeapWord* orig_end() const { return _bottom + GrainWords; } 571 572 // Reset HR stuff to default values. 573 void hr_clear(bool par, bool clear_space, bool locked = false); 574 void par_clear(); 575 576 // Get the start of the unmarked area in this region. 577 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 578 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 579 580 // Note the start or end of marking. This tells the heap region 581 // that the collector is about to start or has finished (concurrently) 582 // marking the heap. 583 584 // Notify the region that concurrent marking is starting. Initialize 585 // all fields related to the next marking info. 586 inline void note_start_of_marking(); 587 588 // Notify the region that concurrent marking has finished. Copy the 589 // (now finalized) next marking info fields into the prev marking 590 // info fields. 591 inline void note_end_of_marking(); 592 593 // Notify the region that it will be used as to-space during a GC 594 // and we are about to start copying objects into it. 595 inline void note_start_of_copying(bool during_initial_mark); 596 597 // Notify the region that it ceases being to-space during a GC and 598 // we will not copy objects into it any more. 599 inline void note_end_of_copying(bool during_initial_mark); 600 601 // Notify the region that we are about to start processing 602 // self-forwarded objects during evac failure handling. 603 void note_self_forwarding_removal_start(bool during_initial_mark, 604 bool during_conc_mark); 605 606 // Notify the region that we have finished processing self-forwarded 607 // objects during evac failure handling. 608 void note_self_forwarding_removal_end(bool during_initial_mark, 609 bool during_conc_mark, 610 size_t marked_bytes); 611 612 // Returns "false" iff no object in the region was allocated when the 613 // last mark phase ended. 614 bool is_marked() { return _prev_top_at_mark_start != bottom(); } 615 616 void reset_during_compaction() { 617 assert(isHumongous() && startsHumongous(), 618 "should only be called for starts humongous regions"); 619 620 zero_marked_bytes(); 621 init_top_at_mark_start(); 622 } 623 624 void calc_gc_efficiency(void); 625 double gc_efficiency() { return _gc_efficiency;} 626 627 int young_index_in_cset() const { return _young_index_in_cset; } 628 void set_young_index_in_cset(int index) { 629 assert( (index == -1) || is_young(), "pre-condition" ); 630 _young_index_in_cset = index; 631 } 632 633 int age_in_surv_rate_group() { 634 assert( _surv_rate_group != NULL, "pre-condition" ); 635 assert( _age_index > -1, "pre-condition" ); 636 return _surv_rate_group->age_in_group(_age_index); 637 } 638 639 void record_surv_words_in_group(size_t words_survived) { 640 assert( _surv_rate_group != NULL, "pre-condition" ); 641 assert( _age_index > -1, "pre-condition" ); 642 int age_in_group = age_in_surv_rate_group(); 643 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 644 } 645 646 int age_in_surv_rate_group_cond() { 647 if (_surv_rate_group != NULL) 648 return age_in_surv_rate_group(); 649 else 650 return -1; 651 } 652 653 SurvRateGroup* surv_rate_group() { 654 return _surv_rate_group; 655 } 656 657 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 658 assert( surv_rate_group != NULL, "pre-condition" ); 659 assert( _surv_rate_group == NULL, "pre-condition" ); 660 assert( is_young(), "pre-condition" ); 661 662 _surv_rate_group = surv_rate_group; 663 _age_index = surv_rate_group->next_age_index(); 664 } 665 666 void uninstall_surv_rate_group() { 667 if (_surv_rate_group != NULL) { 668 assert( _age_index > -1, "pre-condition" ); 669 assert( is_young(), "pre-condition" ); 670 671 _surv_rate_group = NULL; 672 _age_index = -1; 673 } else { 674 assert( _age_index == -1, "pre-condition" ); 675 } 676 } 677 678 void set_free() { _type.set_free(); } 679 680 void set_eden() { _type.set_eden(); } 681 void set_eden_pre_gc() { _type.set_eden_pre_gc(); } 682 void set_survivor() { _type.set_survivor(); } 683 684 void set_old() { _type.set_old(); } 685 686 // Determine if an object has been allocated since the last 687 // mark performed by the collector. This returns true iff the object 688 // is within the unmarked area of the region. 689 bool obj_allocated_since_prev_marking(oop obj) const { 690 return (HeapWord *) obj >= prev_top_at_mark_start(); 691 } 692 bool obj_allocated_since_next_marking(oop obj) const { 693 return (HeapWord *) obj >= next_top_at_mark_start(); 694 } 695 696 // For parallel heapRegion traversal. 697 bool claimHeapRegion(int claimValue); 698 jint claim_value() { return _claimed; } 699 // Use this carefully: only when you're sure no one is claiming... 700 void set_claim_value(int claimValue) { _claimed = claimValue; } 701 702 // Returns the "evacuation_failed" property of the region. 703 bool evacuation_failed() { return _evacuation_failed; } 704 705 // Sets the "evacuation_failed" property of the region. 706 void set_evacuation_failed(bool b) { 707 _evacuation_failed = b; 708 709 if (b) { 710 _next_marked_bytes = 0; 711 } 712 } 713 714 // Requires that "mr" be entirely within the region. 715 // Apply "cl->do_object" to all objects that intersect with "mr". 716 // If the iteration encounters an unparseable portion of the region, 717 // or if "cl->abort()" is true after a closure application, 718 // terminate the iteration and return the address of the start of the 719 // subregion that isn't done. (The two can be distinguished by querying 720 // "cl->abort()".) Return of "NULL" indicates that the iteration 721 // completed. 722 HeapWord* 723 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl); 724 725 // filter_young: if true and the region is a young region then we 726 // skip the iteration. 727 // card_ptr: if not NULL, and we decide that the card is not young 728 // and we iterate over it, we'll clean the card before we start the 729 // iteration. 730 HeapWord* 731 oops_on_card_seq_iterate_careful(MemRegion mr, 732 FilterOutOfRegionClosure* cl, 733 bool filter_young, 734 jbyte* card_ptr); 735 736 size_t recorded_rs_length() const { return _recorded_rs_length; } 737 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 738 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; } 739 740 void set_recorded_rs_length(size_t rs_length) { 741 _recorded_rs_length = rs_length; 742 } 743 744 void set_predicted_elapsed_time_ms(double ms) { 745 _predicted_elapsed_time_ms = ms; 746 } 747 748 void set_predicted_bytes_to_copy(size_t bytes) { 749 _predicted_bytes_to_copy = bytes; 750 } 751 752 virtual CompactibleSpace* next_compaction_space() const; 753 754 virtual void reset_after_compaction(); 755 756 // Routines for managing a list of code roots (attached to the 757 // this region's RSet) that point into this heap region. 758 void add_strong_code_root(nmethod* nm); 759 void add_strong_code_root_locked(nmethod* nm); 760 void remove_strong_code_root(nmethod* nm); 761 762 // Applies blk->do_code_blob() to each of the entries in 763 // the strong code roots list for this region 764 void strong_code_roots_do(CodeBlobClosure* blk) const; 765 766 // Verify that the entries on the strong code root list for this 767 // region are live and include at least one pointer into this region. 768 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 769 770 void print() const; 771 void print_on(outputStream* st) const; 772 773 // vo == UsePrevMarking -> use "prev" marking information, 774 // vo == UseNextMarking -> use "next" marking information 775 // vo == UseMarkWord -> use the mark word in the object header 776 // 777 // NOTE: Only the "prev" marking information is guaranteed to be 778 // consistent most of the time, so most calls to this should use 779 // vo == UsePrevMarking. 780 // Currently, there is only one case where this is called with 781 // vo == UseNextMarking, which is to verify the "next" marking 782 // information at the end of remark. 783 // Currently there is only one place where this is called with 784 // vo == UseMarkWord, which is to verify the marking during a 785 // full GC. 786 void verify(VerifyOption vo, bool *failures) const; 787 788 // Override; it uses the "prev" marking information 789 virtual void verify() const; 790 }; 791 792 // HeapRegionClosure is used for iterating over regions. 793 // Terminates the iteration when the "doHeapRegion" method returns "true". 794 class HeapRegionClosure : public StackObj { 795 friend class HeapRegionManager; 796 friend class G1CollectedHeap; 797 798 bool _complete; 799 void incomplete() { _complete = false; } 800 801 public: 802 HeapRegionClosure(): _complete(true) {} 803 804 // Typically called on each region until it returns true. 805 virtual bool doHeapRegion(HeapRegion* r) = 0; 806 807 // True after iteration if the closure was applied to all heap regions 808 // and returned "false" in all cases. 809 bool complete() { return _complete; } 810 }; 811 812 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP