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/g1AllocationContext.hpp" 29 #include "gc_implementation/g1/g1BlockOffsetTable.hpp" 30 #include "gc_implementation/g1/g1_specialized_oop_closures.hpp" 31 #include "gc_implementation/g1/heapRegionType.hpp" 32 #include "gc_implementation/g1/survRateGroup.hpp" 33 #include "gc_implementation/shared/ageTable.hpp" 34 #include "gc_implementation/shared/spaceDecorator.hpp" 35 #include "memory/space.inline.hpp" 36 #include "memory/watermark.hpp" 37 #include "utilities/macros.hpp" 38 39 // A HeapRegion is the smallest piece of a G1CollectedHeap that 40 // can be collected independently. 41 42 // NOTE: Although a HeapRegion is a Space, its 43 // Space::initDirtyCardClosure method must not be called. 44 // The problem is that the existence of this method breaks 45 // the independence of barrier sets from remembered sets. 46 // The solution is to remove this method from the definition 47 // of a Space. 48 49 class HeapRegionRemSet; 50 class HeapRegionRemSetIterator; 51 class HeapRegion; 52 class HeapRegionSetBase; 53 class nmethod; 54 55 #define HR_FORMAT "%u:(%s)["PTR_FORMAT","PTR_FORMAT","PTR_FORMAT"]" 56 #define HR_FORMAT_PARAMS(_hr_) \ 57 (_hr_)->hrm_index(), \ 58 (_hr_)->get_short_type_str(), \ 59 p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end()) 60 61 // sentinel value for hrm_index 62 #define G1_NO_HRM_INDEX ((uint) -1) 63 64 // A dirty card to oop closure for heap regions. It 65 // knows how to get the G1 heap and how to use the bitmap 66 // in the concurrent marker used by G1 to filter remembered 67 // sets. 68 69 class HeapRegionDCTOC : public DirtyCardToOopClosure { 70 public: 71 // Specification of possible DirtyCardToOopClosure filtering. 72 enum FilterKind { 73 NoFilterKind, 74 IntoCSFilterKind, 75 OutOfRegionFilterKind 76 }; 77 78 protected: 79 HeapRegion* _hr; 80 FilterKind _fk; 81 G1CollectedHeap* _g1; 82 83 // Walk the given memory region from bottom to (actual) top 84 // looking for objects and applying the oop closure (_cl) to 85 // them. The base implementation of this treats the area as 86 // blocks, where a block may or may not be an object. Sub- 87 // classes should override this to provide more accurate 88 // or possibly more efficient walking. 89 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top); 90 91 public: 92 HeapRegionDCTOC(G1CollectedHeap* g1, 93 HeapRegion* hr, ExtendedOopClosure* cl, 94 CardTableModRefBS::PrecisionStyle precision, 95 FilterKind fk); 96 }; 97 98 // The complicating factor is that BlockOffsetTable diverged 99 // significantly, and we need functionality that is only in the G1 version. 100 // So I copied that code, which led to an alternate G1 version of 101 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could 102 // be reconciled, then G1OffsetTableContigSpace could go away. 103 104 // The idea behind time stamps is the following. We want to keep track of 105 // the highest address where it's safe to scan objects for each region. 106 // This is only relevant for current GC alloc regions so we keep a time stamp 107 // per region to determine if the region has been allocated during the current 108 // GC or not. If the time stamp is current we report a scan_top value which 109 // was saved at the end of the previous GC for retained alloc regions and which is 110 // equal to the bottom for all other regions. 111 // There is a race between card scanners and allocating gc workers where we must ensure 112 // that card scanners do not read the memory allocated by the gc workers. 113 // In order to enforce that, we must not return a value of _top which is more recent than the 114 // time stamp. This is due to the fact that a region may become a gc alloc region at 115 // some point after we've read the timestamp value as being < the current time stamp. 116 // The time stamps are re-initialized to zero at cleanup and at Full GCs. 117 // The current scheme that uses sequential unsigned ints will fail only if we have 4b 118 // evacuation pauses between two cleanups, which is _highly_ unlikely. 119 class G1OffsetTableContigSpace: public CompactibleSpace { 120 friend class VMStructs; 121 HeapWord* _top; 122 HeapWord* volatile _scan_top; 123 protected: 124 G1BlockOffsetArrayContigSpace _offsets; 125 Mutex _par_alloc_lock; 126 volatile unsigned _gc_time_stamp; 127 // When we need to retire an allocation region, while other threads 128 // are also concurrently trying to allocate into it, we typically 129 // allocate a dummy object at the end of the region to ensure that 130 // no more allocations can take place in it. However, sometimes we 131 // want to know where the end of the last "real" object we allocated 132 // into the region was and this is what this keeps track. 133 HeapWord* _pre_dummy_top; 134 135 public: 136 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray, 137 MemRegion mr); 138 139 void set_top(HeapWord* value) { _top = value; } 140 HeapWord* top() const { return _top; } 141 142 protected: 143 // Reset the G1OffsetTableContigSpace. 144 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); 145 146 HeapWord** top_addr() { return &_top; } 147 // Allocation helpers (return NULL if full). 148 inline HeapWord* allocate_impl(size_t word_size, HeapWord* end_value); 149 inline HeapWord* par_allocate_impl(size_t word_size, HeapWord* end_value); 150 151 public: 152 void reset_after_compaction() { set_top(compaction_top()); } 153 154 size_t used() const { return byte_size(bottom(), top()); } 155 size_t free() const { return byte_size(top(), end()); } 156 bool is_free_block(const HeapWord* p) const { return p >= top(); } 157 158 MemRegion used_region() const { return MemRegion(bottom(), top()); } 159 160 void object_iterate(ObjectClosure* blk); 161 void safe_object_iterate(ObjectClosure* blk); 162 163 void set_bottom(HeapWord* value); 164 void set_end(HeapWord* value); 165 166 HeapWord* scan_top() const; 167 void record_timestamp(); 168 void reset_gc_time_stamp() { _gc_time_stamp = 0; } 169 unsigned get_gc_time_stamp() { return _gc_time_stamp; } 170 void record_retained_region(); 171 172 // See the comment above in the declaration of _pre_dummy_top for an 173 // explanation of what it is. 174 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 175 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 176 _pre_dummy_top = pre_dummy_top; 177 } 178 HeapWord* pre_dummy_top() { 179 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; 180 } 181 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 182 183 virtual void clear(bool mangle_space); 184 185 HeapWord* block_start(const void* p); 186 HeapWord* block_start_const(const void* p) const; 187 188 // Add offset table update. 189 virtual HeapWord* allocate(size_t word_size); 190 HeapWord* par_allocate(size_t word_size); 191 192 HeapWord* saved_mark_word() const { ShouldNotReachHere(); return NULL; } 193 194 // MarkSweep support phase3 195 virtual HeapWord* initialize_threshold(); 196 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 197 198 virtual void print() const; 199 200 void reset_bot() { 201 _offsets.reset_bot(); 202 } 203 204 void print_bot_on(outputStream* out) { 205 _offsets.print_on(out); 206 } 207 }; 208 209 class HeapRegion: public G1OffsetTableContigSpace { 210 friend class VMStructs; 211 // Allow scan_and_forward to call (private) overrides for auxiliary functions on this class 212 template <typename SpaceType> 213 friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp); 214 private: 215 216 // The remembered set for this region. 217 // (Might want to make this "inline" later, to avoid some alloc failure 218 // issues.) 219 HeapRegionRemSet* _rem_set; 220 221 G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; } 222 223 // Auxiliary functions for scan_and_forward support. 224 // See comments for CompactibleSpace for more information. 225 inline HeapWord* scan_limit() const { 226 return top(); 227 } 228 229 inline bool scanned_block_is_obj(const HeapWord* addr) const { 230 return true; // Always true, since scan_limit is top 231 } 232 233 inline size_t scanned_block_size(const HeapWord* addr) const { 234 return HeapRegion::block_size(addr); // Avoid virtual call 235 } 236 237 protected: 238 // The index of this region in the heap region sequence. 239 uint _hrm_index; 240 241 AllocationContext_t _allocation_context; 242 243 HeapRegionType _type; 244 245 // For a humongous region, region in which it starts. 246 HeapRegion* _humongous_start_region; 247 // True iff the region is in current collection_set. 248 bool _in_collection_set; 249 250 // True iff an attempt to evacuate an object in the region failed. 251 bool _evacuation_failed; 252 253 // A heap region may be a member one of a number of special subsets, each 254 // represented as linked lists through the field below. Currently, there 255 // is only one set: 256 // The collection set. 257 HeapRegion* _next_in_special_set; 258 259 // next region in the young "generation" region set 260 HeapRegion* _next_young_region; 261 262 // Next region whose cards need cleaning 263 HeapRegion* _next_dirty_cards_region; 264 265 // Fields used by the HeapRegionSetBase class and subclasses. 266 HeapRegion* _next; 267 HeapRegion* _prev; 268 #ifdef ASSERT 269 HeapRegionSetBase* _containing_set; 270 #endif // ASSERT 271 272 // We use concurrent marking to determine the amount of live data 273 // in each heap region. 274 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 275 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 276 277 // The calculated GC efficiency of the region. 278 double _gc_efficiency; 279 280 int _young_index_in_cset; 281 SurvRateGroup* _surv_rate_group; 282 int _age_index; 283 284 // The start of the unmarked area. The unmarked area extends from this 285 // word until the top and/or end of the region, and is the part 286 // of the region for which no marking was done, i.e. objects may 287 // have been allocated in this part since the last mark phase. 288 // "prev" is the top at the start of the last completed marking. 289 // "next" is the top at the start of the in-progress marking (if any.) 290 HeapWord* _prev_top_at_mark_start; 291 HeapWord* _next_top_at_mark_start; 292 // If a collection pause is in progress, this is the top at the start 293 // of that pause. 294 295 void init_top_at_mark_start() { 296 assert(_prev_marked_bytes == 0 && 297 _next_marked_bytes == 0, 298 "Must be called after zero_marked_bytes."); 299 HeapWord* bot = bottom(); 300 _prev_top_at_mark_start = bot; 301 _next_top_at_mark_start = bot; 302 } 303 304 // Cached attributes used in the collection set policy information 305 306 // The RSet length that was added to the total value 307 // for the collection set. 308 size_t _recorded_rs_length; 309 310 // The predicted elapsed time that was added to total value 311 // for the collection set. 312 double _predicted_elapsed_time_ms; 313 314 // The predicted number of bytes to copy that was added to 315 // the total value for the collection set. 316 size_t _predicted_bytes_to_copy; 317 318 public: 319 HeapRegion(uint hrm_index, 320 G1BlockOffsetSharedArray* sharedOffsetArray, 321 MemRegion mr); 322 323 // Initializing the HeapRegion not only resets the data structure, but also 324 // resets the BOT for that heap region. 325 // The default values for clear_space means that we will do the clearing if 326 // there's clearing to be done ourselves. We also always mangle the space. 327 virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 328 329 static int LogOfHRGrainBytes; 330 static int LogOfHRGrainWords; 331 332 static size_t GrainBytes; 333 static size_t GrainWords; 334 static size_t CardsPerRegion; 335 336 static size_t align_up_to_region_byte_size(size_t sz) { 337 return (sz + (size_t) GrainBytes - 1) & 338 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 339 } 340 341 static size_t max_region_size(); 342 343 // It sets up the heap region size (GrainBytes / GrainWords), as 344 // well as other related fields that are based on the heap region 345 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 346 // CardsPerRegion). All those fields are considered constant 347 // throughout the JVM's execution, therefore they should only be set 348 // up once during initialization time. 349 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 350 351 // All allocated blocks are occupied by objects in a HeapRegion 352 bool block_is_obj(const HeapWord* p) const; 353 354 // Returns the object size for all valid block starts 355 // and the amount of unallocated words if called on top() 356 size_t block_size(const HeapWord* p) const; 357 358 // Override for scan_and_forward support. 359 void prepare_for_compaction(CompactPoint* cp); 360 361 inline HeapWord* par_allocate_no_bot_updates(size_t word_size); 362 inline HeapWord* allocate_no_bot_updates(size_t word_size); 363 364 // If this region is a member of a HeapRegionManager, the index in that 365 // sequence, otherwise -1. 366 uint hrm_index() const { return _hrm_index; } 367 368 // The number of bytes marked live in the region in the last marking phase. 369 size_t marked_bytes() { return _prev_marked_bytes; } 370 size_t live_bytes() { 371 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 372 } 373 374 // The number of bytes counted in the next marking. 375 size_t next_marked_bytes() { return _next_marked_bytes; } 376 // The number of bytes live wrt the next marking. 377 size_t next_live_bytes() { 378 return 379 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 380 } 381 382 // A lower bound on the amount of garbage bytes in the region. 383 size_t garbage_bytes() { 384 size_t used_at_mark_start_bytes = 385 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 386 assert(used_at_mark_start_bytes >= marked_bytes(), 387 "Can't mark more than we have."); 388 return used_at_mark_start_bytes - marked_bytes(); 389 } 390 391 // Return the amount of bytes we'll reclaim if we collect this 392 // region. This includes not only the known garbage bytes in the 393 // region but also any unallocated space in it, i.e., [top, end), 394 // since it will also be reclaimed if we collect the region. 395 size_t reclaimable_bytes() { 396 size_t known_live_bytes = live_bytes(); 397 assert(known_live_bytes <= capacity(), "sanity"); 398 return capacity() - known_live_bytes; 399 } 400 401 // An upper bound on the number of live bytes in the region. 402 size_t max_live_bytes() { return used() - garbage_bytes(); } 403 404 void add_to_marked_bytes(size_t incr_bytes) { 405 _next_marked_bytes = _next_marked_bytes + incr_bytes; 406 assert(_next_marked_bytes <= used(), "invariant" ); 407 } 408 409 void zero_marked_bytes() { 410 _prev_marked_bytes = _next_marked_bytes = 0; 411 } 412 413 const char* get_type_str() const { return _type.get_str(); } 414 const char* get_short_type_str() const { return _type.get_short_str(); } 415 416 bool is_free() const { return _type.is_free(); } 417 418 bool is_young() const { return _type.is_young(); } 419 bool is_eden() const { return _type.is_eden(); } 420 bool is_survivor() const { return _type.is_survivor(); } 421 422 bool is_humongous() const { return _type.is_humongous(); } 423 bool is_starts_humongous() const { return _type.is_starts_humongous(); } 424 bool is_continues_humongous() const { return _type.is_continues_humongous(); } 425 426 bool is_old() const { return _type.is_old(); } 427 428 // For a humongous region, region in which it starts. 429 HeapRegion* humongous_start_region() const { 430 return _humongous_start_region; 431 } 432 433 // Return the number of distinct regions that are covered by this region: 434 // 1 if the region is not humongous, >= 1 if the region is humongous. 435 uint region_num() const { 436 if (!is_humongous()) { 437 return 1U; 438 } else { 439 assert(is_starts_humongous(), "doesn't make sense on HC regions"); 440 assert(capacity() % HeapRegion::GrainBytes == 0, "sanity"); 441 return (uint) (capacity() >> HeapRegion::LogOfHRGrainBytes); 442 } 443 } 444 445 // Return the index + 1 of the last HC regions that's associated 446 // with this HS region. 447 uint last_hc_index() const { 448 assert(is_starts_humongous(), "don't call this otherwise"); 449 return hrm_index() + region_num(); 450 } 451 452 // Same as Space::is_in_reserved, but will use the original size of the region. 453 // The original size is different only for start humongous regions. They get 454 // their _end set up to be the end of the last continues region of the 455 // corresponding humongous object. 456 bool is_in_reserved_raw(const void* p) const { 457 return _bottom <= p && p < orig_end(); 458 } 459 460 // Makes the current region be a "starts humongous" region, i.e., 461 // the first region in a series of one or more contiguous regions 462 // that will contain a single "humongous" object. The two parameters 463 // are as follows: 464 // 465 // new_top : The new value of the top field of this region which 466 // points to the end of the humongous object that's being 467 // allocated. If there is more than one region in the series, top 468 // will lie beyond this region's original end field and on the last 469 // region in the series. 470 // 471 // new_end : The new value of the end field of this region which 472 // points to the end of the last region in the series. If there is 473 // one region in the series (namely: this one) end will be the same 474 // as the original end of this region. 475 // 476 // Updating top and end as described above makes this region look as 477 // if it spans the entire space taken up by all the regions in the 478 // series and an single allocation moved its top to new_top. This 479 // ensures that the space (capacity / allocated) taken up by all 480 // humongous regions can be calculated by just looking at the 481 // "starts humongous" regions and by ignoring the "continues 482 // humongous" regions. 483 void set_starts_humongous(HeapWord* new_top, HeapWord* new_end); 484 485 // Makes the current region be a "continues humongous' 486 // region. first_hr is the "start humongous" region of the series 487 // which this region will be part of. 488 void set_continues_humongous(HeapRegion* first_hr); 489 490 // Unsets the humongous-related fields on the region. 491 void clear_humongous(); 492 493 // If the region has a remembered set, return a pointer to it. 494 HeapRegionRemSet* rem_set() const { 495 return _rem_set; 496 } 497 498 // True iff the region is in current collection_set. 499 bool in_collection_set() const { 500 return _in_collection_set; 501 } 502 void set_in_collection_set(bool b) { 503 _in_collection_set = b; 504 } 505 HeapRegion* next_in_collection_set() { 506 assert(in_collection_set(), "should only invoke on member of CS."); 507 assert(_next_in_special_set == NULL || 508 _next_in_special_set->in_collection_set(), 509 "Malformed CS."); 510 return _next_in_special_set; 511 } 512 void set_next_in_collection_set(HeapRegion* r) { 513 assert(in_collection_set(), "should only invoke on member of CS."); 514 assert(r == NULL || r->in_collection_set(), "Malformed CS."); 515 _next_in_special_set = r; 516 } 517 518 void set_allocation_context(AllocationContext_t context) { 519 _allocation_context = context; 520 } 521 522 AllocationContext_t allocation_context() const { 523 return _allocation_context; 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(is_starts_humongous(), 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 // Returns the "evacuation_failed" property of the region. 697 bool evacuation_failed() { return _evacuation_failed; } 698 699 // Sets the "evacuation_failed" property of the region. 700 void set_evacuation_failed(bool b) { 701 _evacuation_failed = b; 702 703 if (b) { 704 _next_marked_bytes = 0; 705 } 706 } 707 708 // Requires that "mr" be entirely within the region. 709 // Apply "cl->do_object" to all objects that intersect with "mr". 710 // If the iteration encounters an unparseable portion of the region, 711 // or if "cl->abort()" is true after a closure application, 712 // terminate the iteration and return the address of the start of the 713 // subregion that isn't done. (The two can be distinguished by querying 714 // "cl->abort()".) Return of "NULL" indicates that the iteration 715 // completed. 716 HeapWord* 717 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl); 718 719 // filter_young: if true and the region is a young region then we 720 // skip the iteration. 721 // card_ptr: if not NULL, and we decide that the card is not young 722 // and we iterate over it, we'll clean the card before we start the 723 // iteration. 724 HeapWord* 725 oops_on_card_seq_iterate_careful(MemRegion mr, 726 FilterOutOfRegionClosure* cl, 727 bool filter_young, 728 jbyte* card_ptr); 729 730 size_t recorded_rs_length() const { return _recorded_rs_length; } 731 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 732 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; } 733 734 void set_recorded_rs_length(size_t rs_length) { 735 _recorded_rs_length = rs_length; 736 } 737 738 void set_predicted_elapsed_time_ms(double ms) { 739 _predicted_elapsed_time_ms = ms; 740 } 741 742 void set_predicted_bytes_to_copy(size_t bytes) { 743 _predicted_bytes_to_copy = bytes; 744 } 745 746 virtual CompactibleSpace* next_compaction_space() const; 747 748 virtual void reset_after_compaction(); 749 750 // Routines for managing a list of code roots (attached to the 751 // this region's RSet) that point into this heap region. 752 void add_strong_code_root(nmethod* nm); 753 void add_strong_code_root_locked(nmethod* nm); 754 void remove_strong_code_root(nmethod* nm); 755 756 // Applies blk->do_code_blob() to each of the entries in 757 // the strong code roots list for this region 758 void strong_code_roots_do(CodeBlobClosure* blk) const; 759 760 // Verify that the entries on the strong code root list for this 761 // region are live and include at least one pointer into this region. 762 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 763 764 void print() const; 765 void print_on(outputStream* st) const; 766 767 // vo == UsePrevMarking -> use "prev" marking information, 768 // vo == UseNextMarking -> use "next" marking information 769 // vo == UseMarkWord -> use the mark word in the object header 770 // 771 // NOTE: Only the "prev" marking information is guaranteed to be 772 // consistent most of the time, so most calls to this should use 773 // vo == UsePrevMarking. 774 // Currently, there is only one case where this is called with 775 // vo == UseNextMarking, which is to verify the "next" marking 776 // information at the end of remark. 777 // Currently there is only one place where this is called with 778 // vo == UseMarkWord, which is to verify the marking during a 779 // full GC. 780 void verify(VerifyOption vo, bool *failures) const; 781 782 // Override; it uses the "prev" marking information 783 virtual void verify() const; 784 }; 785 786 // HeapRegionClosure is used for iterating over regions. 787 // Terminates the iteration when the "doHeapRegion" method returns "true". 788 class HeapRegionClosure : public StackObj { 789 friend class HeapRegionManager; 790 friend class G1CollectedHeap; 791 792 bool _complete; 793 void incomplete() { _complete = false; } 794 795 public: 796 HeapRegionClosure(): _complete(true) {} 797 798 // Typically called on each region until it returns true. 799 virtual bool doHeapRegion(HeapRegion* r) = 0; 800 801 // True after iteration if the closure was applied to all heap regions 802 // and returned "false" in all cases. 803 bool complete() { return _complete; } 804 }; 805 806 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP