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 #include "gc_implementation/g1/g1HeapRegionTraceType.hpp" 39 40 // A HeapRegion is the smallest piece of a G1CollectedHeap that 41 // can be collected independently. 42 43 // NOTE: Although a HeapRegion is a Space, its 44 // Space::initDirtyCardClosure method must not be called. 45 // The problem is that the existence of this method breaks 46 // the independence of barrier sets from remembered sets. 47 // The solution is to remove this method from the definition 48 // of a Space. 49 50 class HeapRegionRemSet; 51 class HeapRegionRemSetIterator; 52 class HeapRegion; 53 class HeapRegionSetBase; 54 class nmethod; 55 56 #define HR_FORMAT "%u:(%s)[" PTR_FORMAT "," PTR_FORMAT "," PTR_FORMAT "]" 57 #define HR_FORMAT_PARAMS(_hr_) \ 58 (_hr_)->hrm_index(), \ 59 (_hr_)->get_short_type_str(), \ 60 p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end()) 61 62 // sentinel value for hrm_index 63 #define G1_NO_HRM_INDEX ((uint) -1) 64 65 // A dirty card to oop closure for heap regions. It 66 // knows how to get the G1 heap and how to use the bitmap 67 // in the concurrent marker used by G1 to filter remembered 68 // sets. 69 70 class HeapRegionDCTOC : public DirtyCardToOopClosure { 71 private: 72 HeapRegion* _hr; 73 G1ParPushHeapRSClosure* _rs_scan; 74 G1CollectedHeap* _g1; 75 76 // Walk the given memory region from bottom to (actual) top 77 // looking for objects and applying the oop closure (_cl) to 78 // them. The base implementation of this treats the area as 79 // blocks, where a block may or may not be an object. Sub- 80 // classes should override this to provide more accurate 81 // or possibly more efficient walking. 82 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top); 83 84 public: 85 HeapRegionDCTOC(G1CollectedHeap* g1, 86 HeapRegion* hr, 87 G1ParPushHeapRSClosure* cl, 88 CardTableModRefBS::PrecisionStyle precision); 89 }; 90 91 // The complicating factor is that BlockOffsetTable diverged 92 // significantly, and we need functionality that is only in the G1 version. 93 // So I copied that code, which led to an alternate G1 version of 94 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could 95 // be reconciled, then G1OffsetTableContigSpace could go away. 96 97 // The idea behind time stamps is the following. We want to keep track of 98 // the highest address where it's safe to scan objects for each region. 99 // This is only relevant for current GC alloc regions so we keep a time stamp 100 // per region to determine if the region has been allocated during the current 101 // GC or not. If the time stamp is current we report a scan_top value which 102 // was saved at the end of the previous GC for retained alloc regions and which is 103 // equal to the bottom for all other regions. 104 // There is a race between card scanners and allocating gc workers where we must ensure 105 // that card scanners do not read the memory allocated by the gc workers. 106 // In order to enforce that, we must not return a value of _top which is more recent than the 107 // time stamp. This is due to the fact that a region may become a gc alloc region at 108 // some point after we've read the timestamp value as being < the current time stamp. 109 // The time stamps are re-initialized to zero at cleanup and at Full GCs. 110 // The current scheme that uses sequential unsigned ints will fail only if we have 4b 111 // evacuation pauses between two cleanups, which is _highly_ unlikely. 112 class G1OffsetTableContigSpace: public CompactibleSpace { 113 friend class VMStructs; 114 HeapWord* _top; 115 HeapWord* volatile _scan_top; 116 protected: 117 G1BlockOffsetArrayContigSpace _offsets; 118 Mutex _par_alloc_lock; 119 volatile unsigned _gc_time_stamp; 120 // When we need to retire an allocation region, while other threads 121 // are also concurrently trying to allocate into it, we typically 122 // allocate a dummy object at the end of the region to ensure that 123 // no more allocations can take place in it. However, sometimes we 124 // want to know where the end of the last "real" object we allocated 125 // into the region was and this is what this keeps track. 126 HeapWord* _pre_dummy_top; 127 128 public: 129 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray, 130 MemRegion mr); 131 132 void set_top(HeapWord* value) { _top = value; } 133 HeapWord* top() const { return _top; } 134 135 protected: 136 // Reset the G1OffsetTableContigSpace. 137 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); 138 139 HeapWord** top_addr() { return &_top; } 140 // Allocation helpers (return NULL if full). 141 inline HeapWord* allocate_impl(size_t word_size, HeapWord* end_value); 142 inline HeapWord* par_allocate_impl(size_t word_size, HeapWord* end_value); 143 144 public: 145 void reset_after_compaction() { set_top(compaction_top()); } 146 147 size_t used() const { return byte_size(bottom(), top()); } 148 size_t free() const { return byte_size(top(), end()); } 149 bool is_free_block(const HeapWord* p) const { return p >= top(); } 150 151 MemRegion used_region() const { return MemRegion(bottom(), top()); } 152 153 void object_iterate(ObjectClosure* blk); 154 void safe_object_iterate(ObjectClosure* blk); 155 156 void set_bottom(HeapWord* value); 157 void set_end(HeapWord* value); 158 159 HeapWord* scan_top() const; 160 void record_timestamp(); 161 void reset_gc_time_stamp() { _gc_time_stamp = 0; } 162 unsigned get_gc_time_stamp() { return _gc_time_stamp; } 163 void record_retained_region(); 164 165 // See the comment above in the declaration of _pre_dummy_top for an 166 // explanation of what it is. 167 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 168 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 169 _pre_dummy_top = pre_dummy_top; 170 } 171 HeapWord* pre_dummy_top() { 172 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; 173 } 174 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 175 176 virtual void clear(bool mangle_space); 177 178 HeapWord* block_start(const void* p); 179 HeapWord* block_start_const(const void* p) const; 180 181 void prepare_for_compaction(CompactPoint* cp); 182 183 // Add offset table update. 184 virtual HeapWord* allocate(size_t word_size); 185 HeapWord* par_allocate(size_t word_size); 186 187 HeapWord* saved_mark_word() const { ShouldNotReachHere(); return NULL; } 188 189 // MarkSweep support phase3 190 virtual HeapWord* initialize_threshold(); 191 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 192 193 virtual void print() const; 194 195 void reset_bot() { 196 _offsets.reset_bot(); 197 } 198 199 void print_bot_on(outputStream* out) { 200 _offsets.print_on(out); 201 } 202 }; 203 204 class HeapRegion: public G1OffsetTableContigSpace { 205 friend class VMStructs; 206 private: 207 208 // The remembered set for this region. 209 // (Might want to make this "inline" later, to avoid some alloc failure 210 // issues.) 211 HeapRegionRemSet* _rem_set; 212 213 G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; } 214 215 void report_region_type_change(G1HeapRegionTraceType::Type to); 216 217 protected: 218 // The index of this region in the heap region sequence. 219 uint _hrm_index; 220 221 AllocationContext_t _allocation_context; 222 223 HeapRegionType _type; 224 225 // For a humongous region, region in which it starts. 226 HeapRegion* _humongous_start_region; 227 // For the start region of a humongous sequence, it's original end(). 228 HeapWord* _orig_end; 229 230 // True iff the region is in current collection_set. 231 bool _in_collection_set; 232 233 // True iff an attempt to evacuate an object in the region failed. 234 bool _evacuation_failed; 235 236 // A heap region may be a member one of a number of special subsets, each 237 // represented as linked lists through the field below. Currently, there 238 // is only one set: 239 // The collection set. 240 HeapRegion* _next_in_special_set; 241 242 // next region in the young "generation" region set 243 HeapRegion* _next_young_region; 244 245 // Next region whose cards need cleaning 246 HeapRegion* _next_dirty_cards_region; 247 248 // Fields used by the HeapRegionSetBase class and subclasses. 249 HeapRegion* _next; 250 HeapRegion* _prev; 251 #ifdef ASSERT 252 HeapRegionSetBase* _containing_set; 253 #endif // ASSERT 254 255 // For parallel heapRegion traversal. 256 jint _claimed; 257 258 // We use concurrent marking to determine the amount of live data 259 // in each heap region. 260 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 261 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 262 263 // The calculated GC efficiency of the region. 264 double _gc_efficiency; 265 266 int _young_index_in_cset; 267 SurvRateGroup* _surv_rate_group; 268 int _age_index; 269 270 // The start of the unmarked area. The unmarked area extends from this 271 // word until the top and/or end of the region, and is the part 272 // of the region for which no marking was done, i.e. objects may 273 // have been allocated in this part since the last mark phase. 274 // "prev" is the top at the start of the last completed marking. 275 // "next" is the top at the start of the in-progress marking (if any.) 276 HeapWord* _prev_top_at_mark_start; 277 HeapWord* _next_top_at_mark_start; 278 // If a collection pause is in progress, this is the top at the start 279 // of that pause. 280 281 void init_top_at_mark_start() { 282 assert(_prev_marked_bytes == 0 && 283 _next_marked_bytes == 0, 284 "Must be called after zero_marked_bytes."); 285 HeapWord* bot = bottom(); 286 _prev_top_at_mark_start = bot; 287 _next_top_at_mark_start = bot; 288 } 289 290 // Cached attributes used in the collection set policy information 291 292 // The RSet length that was added to the total value 293 // for the collection set. 294 size_t _recorded_rs_length; 295 296 // The predicted elapsed time that was added to total value 297 // for the collection set. 298 double _predicted_elapsed_time_ms; 299 300 // The predicted number of bytes to copy that was added to 301 // the total value for the collection set. 302 size_t _predicted_bytes_to_copy; 303 304 public: 305 HeapRegion(uint hrm_index, 306 G1BlockOffsetSharedArray* sharedOffsetArray, 307 MemRegion mr); 308 309 // Initializing the HeapRegion not only resets the data structure, but also 310 // resets the BOT for that heap region. 311 // The default values for clear_space means that we will do the clearing if 312 // there's clearing to be done ourselves. We also always mangle the space. 313 virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 314 315 static int LogOfHRGrainBytes; 316 static int LogOfHRGrainWords; 317 318 static size_t GrainBytes; 319 static size_t GrainWords; 320 static size_t CardsPerRegion; 321 322 static size_t align_up_to_region_byte_size(size_t sz) { 323 return (sz + (size_t) GrainBytes - 1) & 324 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 325 } 326 327 static size_t max_region_size(); 328 329 // It sets up the heap region size (GrainBytes / GrainWords), as 330 // well as other related fields that are based on the heap region 331 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 332 // CardsPerRegion). All those fields are considered constant 333 // throughout the JVM's execution, therefore they should only be set 334 // up once during initialization time. 335 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 336 337 enum ClaimValues { 338 InitialClaimValue = 0, 339 FinalCountClaimValue = 1, 340 NoteEndClaimValue = 2, 341 ScrubRemSetClaimValue = 3, 342 ParVerifyClaimValue = 4, 343 RebuildRSClaimValue = 5, 344 ParEvacFailureClaimValue = 6, 345 AggregateCountClaimValue = 7, 346 VerifyCountClaimValue = 8, 347 ParMarkRootClaimValue = 9 348 }; 349 350 // All allocated blocks are occupied by objects in a HeapRegion 351 bool block_is_obj(const HeapWord* p) const; 352 353 // Returns the object size for all valid block starts 354 // and the amount of unallocated words if called on top() 355 size_t block_size(const HeapWord* p) const; 356 357 inline HeapWord* par_allocate_no_bot_updates(size_t word_size); 358 inline HeapWord* allocate_no_bot_updates(size_t word_size); 359 360 // If this region is a member of a HeapRegionManager, the index in that 361 // sequence, otherwise -1. 362 uint hrm_index() const { return _hrm_index; } 363 364 // The number of bytes marked live in the region in the last marking phase. 365 size_t marked_bytes() { return _prev_marked_bytes; } 366 size_t live_bytes() { 367 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 368 } 369 370 // The number of bytes counted in the next marking. 371 size_t next_marked_bytes() { return _next_marked_bytes; } 372 // The number of bytes live wrt the next marking. 373 size_t next_live_bytes() { 374 return 375 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 376 } 377 378 // A lower bound on the amount of garbage bytes in the region. 379 size_t garbage_bytes() { 380 size_t used_at_mark_start_bytes = 381 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 382 assert(used_at_mark_start_bytes >= marked_bytes(), 383 "Can't mark more than we have."); 384 return used_at_mark_start_bytes - marked_bytes(); 385 } 386 387 // Return the amount of bytes we'll reclaim if we collect this 388 // region. This includes not only the known garbage bytes in the 389 // region but also any unallocated space in it, i.e., [top, end), 390 // since it will also be reclaimed if we collect the region. 391 size_t reclaimable_bytes() { 392 size_t known_live_bytes = live_bytes(); 393 assert(known_live_bytes <= capacity(), "sanity"); 394 return capacity() - known_live_bytes; 395 } 396 397 // An upper bound on the number of live bytes in the region. 398 size_t max_live_bytes() { return used() - garbage_bytes(); } 399 400 void add_to_marked_bytes(size_t incr_bytes) { 401 _next_marked_bytes = _next_marked_bytes + incr_bytes; 402 assert(_next_marked_bytes <= used(), "invariant" ); 403 } 404 405 void zero_marked_bytes() { 406 _prev_marked_bytes = _next_marked_bytes = 0; 407 } 408 409 const char* get_type_str() const { return _type.get_str(); } 410 const char* get_short_type_str() const { return _type.get_short_str(); } 411 G1HeapRegionTraceType::Type get_trace_type() { return _type.get_trace_type(); } 412 413 bool is_free() const { return _type.is_free(); } 414 415 bool is_young() const { return _type.is_young(); } 416 bool is_eden() const { return _type.is_eden(); } 417 bool is_survivor() const { return _type.is_survivor(); } 418 419 bool isHumongous() const { return _type.is_humongous(); } 420 bool startsHumongous() const { return _type.is_starts_humongous(); } 421 bool continuesHumongous() const { return _type.is_continues_humongous(); } 422 423 bool is_old() const { return _type.is_old(); } 424 425 // For a humongous region, region in which it starts. 426 HeapRegion* humongous_start_region() const { 427 return _humongous_start_region; 428 } 429 430 // Return the number of distinct regions that are covered by this region: 431 // 1 if the region is not humongous, >= 1 if the region is humongous. 432 uint region_num() const { 433 if (!isHumongous()) { 434 return 1U; 435 } else { 436 assert(startsHumongous(), "doesn't make sense on HC regions"); 437 assert(capacity() % HeapRegion::GrainBytes == 0, "sanity"); 438 return (uint) (capacity() >> HeapRegion::LogOfHRGrainBytes); 439 } 440 } 441 442 // Return the index + 1 of the last HC regions that's associated 443 // with this HS region. 444 uint last_hc_index() const { 445 assert(startsHumongous(), "don't call this otherwise"); 446 return hrm_index() + region_num(); 447 } 448 449 // Same as Space::is_in_reserved, but will use the original size of the region. 450 // The original size is different only for start humongous regions. They get 451 // their _end set up to be the end of the last continues region of the 452 // corresponding humongous object. 453 bool is_in_reserved_raw(const void* p) const { 454 return _bottom <= p && p < _orig_end; 455 } 456 457 // Makes the current region be a "starts humongous" region, i.e., 458 // the first region in a series of one or more contiguous regions 459 // that will contain a single "humongous" object. The two parameters 460 // are as follows: 461 // 462 // new_top : The new value of the top field of this region which 463 // points to the end of the humongous object that's being 464 // allocated. If there is more than one region in the series, top 465 // will lie beyond this region's original end field and on the last 466 // region in the series. 467 // 468 // new_end : The new value of the end field of this region which 469 // points to the end of the last region in the series. If there is 470 // one region in the series (namely: this one) end will be the same 471 // as the original end of this region. 472 // 473 // Updating top and end as described above makes this region look as 474 // if it spans the entire space taken up by all the regions in the 475 // series and an single allocation moved its top to new_top. This 476 // ensures that the space (capacity / allocated) taken up by all 477 // humongous regions can be calculated by just looking at the 478 // "starts humongous" regions and by ignoring the "continues 479 // humongous" regions. 480 void set_startsHumongous(HeapWord* new_top, HeapWord* new_end); 481 482 // Makes the current region be a "continues humongous' 483 // region. first_hr is the "start humongous" region of the series 484 // which this region will be part of. 485 void set_continuesHumongous(HeapRegion* first_hr); 486 487 // Unsets the humongous-related fields on the region. 488 void clear_humongous(); 489 490 // If the region has a remembered set, return a pointer to it. 491 HeapRegionRemSet* rem_set() const { 492 return _rem_set; 493 } 494 495 // True iff the region is in current collection_set. 496 bool in_collection_set() const { 497 return _in_collection_set; 498 } 499 void set_in_collection_set(bool b) { 500 _in_collection_set = b; 501 } 502 HeapRegion* next_in_collection_set() { 503 assert(in_collection_set(), "should only invoke on member of CS."); 504 assert(_next_in_special_set == NULL || 505 _next_in_special_set->in_collection_set(), 506 "Malformed CS."); 507 return _next_in_special_set; 508 } 509 void set_next_in_collection_set(HeapRegion* r) { 510 assert(in_collection_set(), "should only invoke on member of CS."); 511 assert(r == NULL || r->in_collection_set(), "Malformed CS."); 512 _next_in_special_set = r; 513 } 514 515 void set_allocation_context(AllocationContext_t context) { 516 _allocation_context = context; 517 } 518 519 AllocationContext_t allocation_context() const { 520 return _allocation_context; 521 } 522 523 // Methods used by the HeapRegionSetBase class and subclasses. 524 525 // Getter and setter for the next and prev fields used to link regions into 526 // linked lists. 527 HeapRegion* next() { return _next; } 528 HeapRegion* prev() { return _prev; } 529 530 void set_next(HeapRegion* next) { _next = next; } 531 void set_prev(HeapRegion* prev) { _prev = prev; } 532 533 // Every region added to a set is tagged with a reference to that 534 // set. This is used for doing consistency checking to make sure that 535 // the contents of a set are as they should be and it's only 536 // available in non-product builds. 537 #ifdef ASSERT 538 void set_containing_set(HeapRegionSetBase* containing_set) { 539 assert((containing_set == NULL && _containing_set != NULL) || 540 (containing_set != NULL && _containing_set == NULL), 541 err_msg("containing_set: " PTR_FORMAT " " 542 "_containing_set: " PTR_FORMAT, 543 p2i(containing_set), p2i(_containing_set))); 544 545 _containing_set = containing_set; 546 } 547 548 HeapRegionSetBase* containing_set() { return _containing_set; } 549 #else // ASSERT 550 void set_containing_set(HeapRegionSetBase* containing_set) { } 551 552 // containing_set() is only used in asserts so there's no reason 553 // to provide a dummy version of it. 554 #endif // ASSERT 555 556 HeapRegion* get_next_young_region() { return _next_young_region; } 557 void set_next_young_region(HeapRegion* hr) { 558 _next_young_region = hr; 559 } 560 561 HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; } 562 HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; } 563 void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; } 564 bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; } 565 566 HeapWord* orig_end() const { return _orig_end; } 567 568 // Reset HR stuff to default values. 569 void hr_clear(bool par, bool clear_space, bool locked = false); 570 void par_clear(); 571 572 // Get the start of the unmarked area in this region. 573 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 574 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 575 576 // Note the start or end of marking. This tells the heap region 577 // that the collector is about to start or has finished (concurrently) 578 // marking the heap. 579 580 // Notify the region that concurrent marking is starting. Initialize 581 // all fields related to the next marking info. 582 inline void note_start_of_marking(); 583 584 // Notify the region that concurrent marking has finished. Copy the 585 // (now finalized) next marking info fields into the prev marking 586 // info fields. 587 inline void note_end_of_marking(); 588 589 // Notify the region that it will be used as to-space during a GC 590 // and we are about to start copying objects into it. 591 inline void note_start_of_copying(bool during_initial_mark); 592 593 // Notify the region that it ceases being to-space during a GC and 594 // we will not copy objects into it any more. 595 inline void note_end_of_copying(bool during_initial_mark); 596 597 // Notify the region that we are about to start processing 598 // self-forwarded objects during evac failure handling. 599 void note_self_forwarding_removal_start(bool during_initial_mark, 600 bool during_conc_mark); 601 602 // Notify the region that we have finished processing self-forwarded 603 // objects during evac failure handling. 604 void note_self_forwarding_removal_end(bool during_initial_mark, 605 bool during_conc_mark, 606 size_t marked_bytes); 607 608 // Returns "false" iff no object in the region was allocated when the 609 // last mark phase ended. 610 bool is_marked() { return _prev_top_at_mark_start != bottom(); } 611 612 void reset_during_compaction() { 613 assert(isHumongous() && startsHumongous(), 614 "should only be called for starts humongous regions"); 615 616 zero_marked_bytes(); 617 init_top_at_mark_start(); 618 } 619 620 void calc_gc_efficiency(void); 621 double gc_efficiency() { return _gc_efficiency;} 622 623 int young_index_in_cset() const { return _young_index_in_cset; } 624 void set_young_index_in_cset(int index) { 625 assert( (index == -1) || is_young(), "pre-condition" ); 626 _young_index_in_cset = index; 627 } 628 629 int age_in_surv_rate_group() { 630 assert( _surv_rate_group != NULL, "pre-condition" ); 631 assert( _age_index > -1, "pre-condition" ); 632 return _surv_rate_group->age_in_group(_age_index); 633 } 634 635 void record_surv_words_in_group(size_t words_survived) { 636 assert( _surv_rate_group != NULL, "pre-condition" ); 637 assert( _age_index > -1, "pre-condition" ); 638 int age_in_group = age_in_surv_rate_group(); 639 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 640 } 641 642 int age_in_surv_rate_group_cond() { 643 if (_surv_rate_group != NULL) 644 return age_in_surv_rate_group(); 645 else 646 return -1; 647 } 648 649 SurvRateGroup* surv_rate_group() { 650 return _surv_rate_group; 651 } 652 653 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 654 assert( surv_rate_group != NULL, "pre-condition" ); 655 assert( _surv_rate_group == NULL, "pre-condition" ); 656 assert( is_young(), "pre-condition" ); 657 658 _surv_rate_group = surv_rate_group; 659 _age_index = surv_rate_group->next_age_index(); 660 } 661 662 void uninstall_surv_rate_group() { 663 if (_surv_rate_group != NULL) { 664 assert( _age_index > -1, "pre-condition" ); 665 assert( is_young(), "pre-condition" ); 666 667 _surv_rate_group = NULL; 668 _age_index = -1; 669 } else { 670 assert( _age_index == -1, "pre-condition" ); 671 } 672 } 673 674 void set_free(); 675 676 void set_eden(); 677 void set_eden_pre_gc(); 678 void set_survivor(); 679 680 void set_old(); 681 682 // Determine if an object has been allocated since the last 683 // mark performed by the collector. This returns true iff the object 684 // is within the unmarked area of the region. 685 bool obj_allocated_since_prev_marking(oop obj) const { 686 return (HeapWord *) obj >= prev_top_at_mark_start(); 687 } 688 bool obj_allocated_since_next_marking(oop obj) const { 689 return (HeapWord *) obj >= next_top_at_mark_start(); 690 } 691 692 // For parallel heapRegion traversal. 693 bool claimHeapRegion(int claimValue); 694 jint claim_value() { return _claimed; } 695 // Use this carefully: only when you're sure no one is claiming... 696 void set_claim_value(int claimValue) { _claimed = claimValue; } 697 698 // Returns the "evacuation_failed" property of the region. 699 bool evacuation_failed() { return _evacuation_failed; } 700 701 // Sets the "evacuation_failed" property of the region. 702 void set_evacuation_failed(bool b) { 703 _evacuation_failed = b; 704 705 if (b) { 706 _next_marked_bytes = 0; 707 } 708 } 709 710 // Requires that "mr" be entirely within the region. 711 // Apply "cl->do_object" to all objects that intersect with "mr". 712 // If the iteration encounters an unparseable portion of the region, 713 // or if "cl->abort()" is true after a closure application, 714 // terminate the iteration and return the address of the start of the 715 // subregion that isn't done. (The two can be distinguished by querying 716 // "cl->abort()".) Return of "NULL" indicates that the iteration 717 // completed. 718 HeapWord* 719 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl); 720 721 // Iterate over the card in the card designated by card_ptr, 722 // applying cl to all references in the region. 723 // mr: the memory region covered by the card. 724 // card_ptr: if we decide that the card is not young and we iterate 725 // over it, we'll clean the card before we start the iteration. 726 // Returns true if the card was successfully processed, false if an 727 // unparsable part of the heap was encountered, which should only 728 // happen when invoked concurrently with the mutator. 729 bool oops_on_card_seq_iterate_careful(MemRegion mr, 730 FilterOutOfRegionClosure* cl, 731 jbyte* card_ptr); 732 733 size_t recorded_rs_length() const { return _recorded_rs_length; } 734 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 735 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; } 736 737 void set_recorded_rs_length(size_t rs_length) { 738 _recorded_rs_length = rs_length; 739 } 740 741 void set_predicted_elapsed_time_ms(double ms) { 742 _predicted_elapsed_time_ms = ms; 743 } 744 745 void set_predicted_bytes_to_copy(size_t bytes) { 746 _predicted_bytes_to_copy = bytes; 747 } 748 749 virtual CompactibleSpace* next_compaction_space() const; 750 751 virtual void reset_after_compaction(); 752 753 // Routines for managing a list of code roots (attached to the 754 // this region's RSet) that point into this heap region. 755 void add_strong_code_root(nmethod* nm); 756 void add_strong_code_root_locked(nmethod* nm); 757 void remove_strong_code_root(nmethod* nm); 758 759 // Applies blk->do_code_blob() to each of the entries in 760 // the strong code roots list for this region 761 void strong_code_roots_do(CodeBlobClosure* blk) const; 762 763 // Verify that the entries on the strong code root list for this 764 // region are live and include at least one pointer into this region. 765 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 766 767 void print() const; 768 void print_on(outputStream* st) const; 769 770 // vo == UsePrevMarking -> use "prev" marking information, 771 // vo == UseNextMarking -> use "next" marking information 772 // vo == UseMarkWord -> use the mark word in the object header 773 // 774 // NOTE: Only the "prev" marking information is guaranteed to be 775 // consistent most of the time, so most calls to this should use 776 // vo == UsePrevMarking. 777 // Currently, there is only one case where this is called with 778 // vo == UseNextMarking, which is to verify the "next" marking 779 // information at the end of remark. 780 // Currently there is only one place where this is called with 781 // vo == UseMarkWord, which is to verify the marking during a 782 // full GC. 783 void verify(VerifyOption vo, bool *failures) const; 784 785 // Override; it uses the "prev" marking information 786 virtual void verify() const; 787 788 void verify_rem_set(VerifyOption vo, bool *failures) const; 789 void verify_rem_set() 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