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 private: 71 HeapRegion* _hr; 72 G1ParPushHeapRSClosure* _rs_scan; 73 G1CollectedHeap* _g1; 74 75 // Walk the given memory region from bottom to (actual) top 76 // looking for objects and applying the oop closure (_cl) to 77 // them. The base implementation of this treats the area as 78 // blocks, where a block may or may not be an object. Sub- 79 // classes should override this to provide more accurate 80 // or possibly more efficient walking. 81 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top); 82 83 public: 84 HeapRegionDCTOC(G1CollectedHeap* g1, 85 HeapRegion* hr, 86 G1ParPushHeapRSClosure* cl, 87 CardTableModRefBS::PrecisionStyle precision); 88 }; 89 90 // The complicating factor is that BlockOffsetTable diverged 91 // significantly, and we need functionality that is only in the G1 version. 92 // So I copied that code, which led to an alternate G1 version of 93 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could 94 // be reconciled, then G1OffsetTableContigSpace could go away. 95 96 // The idea behind time stamps is the following. We want to keep track of 97 // the highest address where it's safe to scan objects for each region. 98 // This is only relevant for current GC alloc regions so we keep a time stamp 99 // per region to determine if the region has been allocated during the current 100 // GC or not. If the time stamp is current we report a scan_top value which 101 // was saved at the end of the previous GC for retained alloc regions and which is 102 // equal to the bottom for all other regions. 103 // There is a race between card scanners and allocating gc workers where we must ensure 104 // that card scanners do not read the memory allocated by the gc workers. 105 // In order to enforce that, we must not return a value of _top which is more recent than the 106 // time stamp. This is due to the fact that a region may become a gc alloc region at 107 // some point after we've read the timestamp value as being < the current time stamp. 108 // The time stamps are re-initialized to zero at cleanup and at Full GCs. 109 // The current scheme that uses sequential unsigned ints will fail only if we have 4b 110 // evacuation pauses between two cleanups, which is _highly_ unlikely. 111 class G1OffsetTableContigSpace: public CompactibleSpace { 112 friend class VMStructs; 113 HeapWord* _top; 114 HeapWord* volatile _scan_top; 115 protected: 116 G1BlockOffsetArrayContigSpace _offsets; 117 Mutex _par_alloc_lock; 118 volatile unsigned _gc_time_stamp; 119 // When we need to retire an allocation region, while other threads 120 // are also concurrently trying to allocate into it, we typically 121 // allocate a dummy object at the end of the region to ensure that 122 // no more allocations can take place in it. However, sometimes we 123 // want to know where the end of the last "real" object we allocated 124 // into the region was and this is what this keeps track. 125 HeapWord* _pre_dummy_top; 126 127 public: 128 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray, 129 MemRegion mr); 130 131 void set_top(HeapWord* value) { _top = value; } 132 HeapWord* top() const { return _top; } 133 134 protected: 135 // Reset the G1OffsetTableContigSpace. 136 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); 137 138 HeapWord** top_addr() { return &_top; } 139 // Allocation helpers (return NULL if full). 140 inline HeapWord* allocate_impl(size_t word_size, HeapWord* end_value); 141 inline HeapWord* par_allocate_impl(size_t word_size, HeapWord* end_value); 142 143 public: 144 void reset_after_compaction() { set_top(compaction_top()); } 145 146 size_t used() const { return byte_size(bottom(), top()); } 147 size_t free() const { return byte_size(top(), end()); } 148 bool is_free_block(const HeapWord* p) const { return p >= top(); } 149 150 MemRegion used_region() const { return MemRegion(bottom(), top()); } 151 152 void object_iterate(ObjectClosure* blk); 153 void safe_object_iterate(ObjectClosure* blk); 154 155 void set_bottom(HeapWord* value); 156 void set_end(HeapWord* value); 157 158 HeapWord* scan_top() const; 159 void record_timestamp(); 160 void reset_gc_time_stamp() { _gc_time_stamp = 0; } 161 unsigned get_gc_time_stamp() { return _gc_time_stamp; } 162 void record_retained_region(); 163 164 // See the comment above in the declaration of _pre_dummy_top for an 165 // explanation of what it is. 166 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 167 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 168 _pre_dummy_top = pre_dummy_top; 169 } 170 HeapWord* pre_dummy_top() { 171 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; 172 } 173 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 174 175 virtual void clear(bool mangle_space); 176 177 HeapWord* block_start(const void* p); 178 HeapWord* block_start_const(const void* p) const; 179 180 // Add offset table update. 181 virtual HeapWord* allocate(size_t word_size); 182 HeapWord* par_allocate(size_t word_size); 183 184 HeapWord* saved_mark_word() const { ShouldNotReachHere(); return NULL; } 185 186 // MarkSweep support phase3 187 virtual HeapWord* initialize_threshold(); 188 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 189 190 virtual void print() const; 191 192 void reset_bot() { 193 _offsets.reset_bot(); 194 } 195 196 void print_bot_on(outputStream* out) { 197 _offsets.print_on(out); 198 } 199 }; 200 201 class HeapRegion: public G1OffsetTableContigSpace { 202 friend class VMStructs; 203 // Allow scan_and_forward to call (private) overrides for auxiliary functions on this class 204 template <typename SpaceType> 205 friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp); 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 // Auxiliary functions for scan_and_forward support. 216 // See comments for CompactibleSpace for more information. 217 inline HeapWord* scan_limit() const { 218 return top(); 219 } 220 221 inline bool scanned_block_is_obj(const HeapWord* addr) const { 222 return true; // Always true, since scan_limit is top 223 } 224 225 inline size_t scanned_block_size(const HeapWord* addr) const { 226 return HeapRegion::block_size(addr); // Avoid virtual call 227 } 228 229 protected: 230 // The index of this region in the heap region sequence. 231 uint _hrm_index; 232 233 AllocationContext_t _allocation_context; 234 235 HeapRegionType _type; 236 237 // For a humongous region, region in which it starts. 238 HeapRegion* _humongous_start_region; 239 240 // True iff an attempt to evacuate an object in the region failed. 241 bool _evacuation_failed; 242 243 // A heap region may be a member one of a number of special subsets, each 244 // represented as linked lists through the field below. Currently, there 245 // is only one set: 246 // The collection set. 247 HeapRegion* _next_in_special_set; 248 249 // next region in the young "generation" region set 250 HeapRegion* _next_young_region; 251 252 // Next region whose cards need cleaning 253 HeapRegion* _next_dirty_cards_region; 254 255 // Fields used by the HeapRegionSetBase class and subclasses. 256 HeapRegion* _next; 257 HeapRegion* _prev; 258 #ifdef ASSERT 259 HeapRegionSetBase* _containing_set; 260 #endif // ASSERT 261 262 // We use concurrent marking to determine the amount of live data 263 // in each heap region. 264 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 265 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 266 267 // The calculated GC efficiency of the region. 268 double _gc_efficiency; 269 270 int _young_index_in_cset; 271 SurvRateGroup* _surv_rate_group; 272 int _age_index; 273 274 // The start of the unmarked area. The unmarked area extends from this 275 // word until the top and/or end of the region, and is the part 276 // of the region for which no marking was done, i.e. objects may 277 // have been allocated in this part since the last mark phase. 278 // "prev" is the top at the start of the last completed marking. 279 // "next" is the top at the start of the in-progress marking (if any.) 280 HeapWord* _prev_top_at_mark_start; 281 HeapWord* _next_top_at_mark_start; 282 // If a collection pause is in progress, this is the top at the start 283 // of that pause. 284 285 void init_top_at_mark_start() { 286 assert(_prev_marked_bytes == 0 && 287 _next_marked_bytes == 0, 288 "Must be called after zero_marked_bytes."); 289 HeapWord* bot = bottom(); 290 _prev_top_at_mark_start = bot; 291 _next_top_at_mark_start = bot; 292 } 293 294 // Cached attributes used in the collection set policy information 295 296 // The RSet length that was added to the total value 297 // for the collection set. 298 size_t _recorded_rs_length; 299 300 // The predicted elapsed time that was added to total value 301 // for the collection set. 302 double _predicted_elapsed_time_ms; 303 304 // The predicted number of bytes to copy that was added to 305 // the total value for the collection set. 306 size_t _predicted_bytes_to_copy; 307 308 public: 309 HeapRegion(uint hrm_index, 310 G1BlockOffsetSharedArray* sharedOffsetArray, 311 MemRegion mr); 312 313 // Initializing the HeapRegion not only resets the data structure, but also 314 // resets the BOT for that heap region. 315 // The default values for clear_space means that we will do the clearing if 316 // there's clearing to be done ourselves. We also always mangle the space. 317 virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 318 319 static int LogOfHRGrainBytes; 320 static int LogOfHRGrainWords; 321 322 static size_t GrainBytes; 323 static size_t GrainWords; 324 static size_t CardsPerRegion; 325 326 static size_t align_up_to_region_byte_size(size_t sz) { 327 return (sz + (size_t) GrainBytes - 1) & 328 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 329 } 330 331 static size_t max_region_size(); 332 333 // It sets up the heap region size (GrainBytes / GrainWords), as 334 // well as other related fields that are based on the heap region 335 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 336 // CardsPerRegion). All those fields are considered constant 337 // throughout the JVM's execution, therefore they should only be set 338 // up once during initialization time. 339 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 340 341 // All allocated blocks are occupied by objects in a HeapRegion 342 bool block_is_obj(const HeapWord* p) const; 343 344 // Returns the object size for all valid block starts 345 // and the amount of unallocated words if called on top() 346 size_t block_size(const HeapWord* p) const; 347 348 // Override for scan_and_forward support. 349 void prepare_for_compaction(CompactPoint* cp); 350 351 inline HeapWord* par_allocate_no_bot_updates(size_t word_size); 352 inline HeapWord* allocate_no_bot_updates(size_t word_size); 353 354 // If this region is a member of a HeapRegionManager, the index in that 355 // sequence, otherwise -1. 356 uint hrm_index() const { return _hrm_index; } 357 358 // The number of bytes marked live in the region in the last marking phase. 359 size_t marked_bytes() { return _prev_marked_bytes; } 360 size_t live_bytes() { 361 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 362 } 363 364 // The number of bytes counted in the next marking. 365 size_t next_marked_bytes() { return _next_marked_bytes; } 366 // The number of bytes live wrt the next marking. 367 size_t next_live_bytes() { 368 return 369 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 370 } 371 372 // A lower bound on the amount of garbage bytes in the region. 373 size_t garbage_bytes() { 374 size_t used_at_mark_start_bytes = 375 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 376 assert(used_at_mark_start_bytes >= marked_bytes(), 377 "Can't mark more than we have."); 378 return used_at_mark_start_bytes - marked_bytes(); 379 } 380 381 // Return the amount of bytes we'll reclaim if we collect this 382 // region. This includes not only the known garbage bytes in the 383 // region but also any unallocated space in it, i.e., [top, end), 384 // since it will also be reclaimed if we collect the region. 385 size_t reclaimable_bytes() { 386 size_t known_live_bytes = live_bytes(); 387 assert(known_live_bytes <= capacity(), "sanity"); 388 return capacity() - known_live_bytes; 389 } 390 391 // An upper bound on the number of live bytes in the region. 392 size_t max_live_bytes() { return used() - garbage_bytes(); } 393 394 void add_to_marked_bytes(size_t incr_bytes) { 395 _next_marked_bytes = _next_marked_bytes + incr_bytes; 396 assert(_next_marked_bytes <= used(), "invariant" ); 397 } 398 399 void zero_marked_bytes() { 400 _prev_marked_bytes = _next_marked_bytes = 0; 401 } 402 403 const char* get_type_str() const { return _type.get_str(); } 404 const char* get_short_type_str() const { return _type.get_short_str(); } 405 406 bool is_free() const { return _type.is_free(); } 407 408 bool is_young() const { return _type.is_young(); } 409 bool is_eden() const { return _type.is_eden(); } 410 bool is_survivor() const { return _type.is_survivor(); } 411 412 bool is_humongous() const { return _type.is_humongous(); } 413 bool is_starts_humongous() const { return _type.is_starts_humongous(); } 414 bool is_continues_humongous() const { return _type.is_continues_humongous(); } 415 416 bool is_old() const { return _type.is_old(); } 417 418 // For a humongous region, region in which it starts. 419 HeapRegion* humongous_start_region() const { 420 return _humongous_start_region; 421 } 422 423 // Return the number of distinct regions that are covered by this region: 424 // 1 if the region is not humongous, >= 1 if the region is humongous. 425 uint region_num() const { 426 if (!is_humongous()) { 427 return 1U; 428 } else { 429 assert(is_starts_humongous(), "doesn't make sense on HC regions"); 430 assert(capacity() % HeapRegion::GrainBytes == 0, "sanity"); 431 return (uint) (capacity() >> HeapRegion::LogOfHRGrainBytes); 432 } 433 } 434 435 // Return the index + 1 of the last HC regions that's associated 436 // with this HS region. 437 uint last_hc_index() const { 438 assert(is_starts_humongous(), "don't call this otherwise"); 439 return hrm_index() + region_num(); 440 } 441 442 // Same as Space::is_in_reserved, but will use the original size of the region. 443 // The original size is different only for start humongous regions. They get 444 // their _end set up to be the end of the last continues region of the 445 // corresponding humongous object. 446 bool is_in_reserved_raw(const void* p) const { 447 return _bottom <= p && p < orig_end(); 448 } 449 450 // Makes the current region be a "starts humongous" region, i.e., 451 // the first region in a series of one or more contiguous regions 452 // that will contain a single "humongous" object. The two parameters 453 // are as follows: 454 // 455 // new_top : The new value of the top field of this region which 456 // points to the end of the humongous object that's being 457 // allocated. If there is more than one region in the series, top 458 // will lie beyond this region's original end field and on the last 459 // region in the series. 460 // 461 // new_end : The new value of the end field of this region which 462 // points to the end of the last region in the series. If there is 463 // one region in the series (namely: this one) end will be the same 464 // as the original end of this region. 465 // 466 // Updating top and end as described above makes this region look as 467 // if it spans the entire space taken up by all the regions in the 468 // series and an single allocation moved its top to new_top. This 469 // ensures that the space (capacity / allocated) taken up by all 470 // humongous regions can be calculated by just looking at the 471 // "starts humongous" regions and by ignoring the "continues 472 // humongous" regions. 473 void set_starts_humongous(HeapWord* new_top, HeapWord* new_end); 474 475 // Makes the current region be a "continues humongous' 476 // region. first_hr is the "start humongous" region of the series 477 // which this region will be part of. 478 void set_continues_humongous(HeapRegion* first_hr); 479 480 // Unsets the humongous-related fields on the region. 481 void clear_humongous(); 482 483 // If the region has a remembered set, return a pointer to it. 484 HeapRegionRemSet* rem_set() const { 485 return _rem_set; 486 } 487 488 bool in_collection_set() const; 489 490 HeapRegion* next_in_collection_set() { 491 assert(in_collection_set(), "should only invoke on member of CS."); 492 assert(_next_in_special_set == NULL || 493 _next_in_special_set->in_collection_set(), 494 "Malformed CS."); 495 return _next_in_special_set; 496 } 497 void set_next_in_collection_set(HeapRegion* r) { 498 assert(in_collection_set(), "should only invoke on member of CS."); 499 assert(r == NULL || r->in_collection_set(), "Malformed CS."); 500 _next_in_special_set = r; 501 } 502 503 void set_allocation_context(AllocationContext_t context) { 504 _allocation_context = context; 505 } 506 507 AllocationContext_t allocation_context() const { 508 return _allocation_context; 509 } 510 511 // Methods used by the HeapRegionSetBase class and subclasses. 512 513 // Getter and setter for the next and prev fields used to link regions into 514 // linked lists. 515 HeapRegion* next() { return _next; } 516 HeapRegion* prev() { return _prev; } 517 518 void set_next(HeapRegion* next) { _next = next; } 519 void set_prev(HeapRegion* prev) { _prev = prev; } 520 521 // Every region added to a set is tagged with a reference to that 522 // set. This is used for doing consistency checking to make sure that 523 // the contents of a set are as they should be and it's only 524 // available in non-product builds. 525 #ifdef ASSERT 526 void set_containing_set(HeapRegionSetBase* containing_set) { 527 assert((containing_set == NULL && _containing_set != NULL) || 528 (containing_set != NULL && _containing_set == NULL), 529 err_msg("containing_set: "PTR_FORMAT" " 530 "_containing_set: "PTR_FORMAT, 531 p2i(containing_set), p2i(_containing_set))); 532 533 _containing_set = containing_set; 534 } 535 536 HeapRegionSetBase* containing_set() { return _containing_set; } 537 #else // ASSERT 538 void set_containing_set(HeapRegionSetBase* containing_set) { } 539 540 // containing_set() is only used in asserts so there's no reason 541 // to provide a dummy version of it. 542 #endif // ASSERT 543 544 HeapRegion* get_next_young_region() { return _next_young_region; } 545 void set_next_young_region(HeapRegion* hr) { 546 _next_young_region = hr; 547 } 548 549 HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; } 550 HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; } 551 void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; } 552 bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; } 553 554 // For the start region of a humongous sequence, it's original end(). 555 HeapWord* orig_end() const { return _bottom + GrainWords; } 556 557 // Reset HR stuff to default values. 558 void hr_clear(bool par, bool clear_space, bool locked = false); 559 void par_clear(); 560 561 // Get the start of the unmarked area in this region. 562 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 563 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 564 565 // Note the start or end of marking. This tells the heap region 566 // that the collector is about to start or has finished (concurrently) 567 // marking the heap. 568 569 // Notify the region that concurrent marking is starting. Initialize 570 // all fields related to the next marking info. 571 inline void note_start_of_marking(); 572 573 // Notify the region that concurrent marking has finished. Copy the 574 // (now finalized) next marking info fields into the prev marking 575 // info fields. 576 inline void note_end_of_marking(); 577 578 // Notify the region that it will be used as to-space during a GC 579 // and we are about to start copying objects into it. 580 inline void note_start_of_copying(bool during_initial_mark); 581 582 // Notify the region that it ceases being to-space during a GC and 583 // we will not copy objects into it any more. 584 inline void note_end_of_copying(bool during_initial_mark); 585 586 // Notify the region that we are about to start processing 587 // self-forwarded objects during evac failure handling. 588 void note_self_forwarding_removal_start(bool during_initial_mark, 589 bool during_conc_mark); 590 591 // Notify the region that we have finished processing self-forwarded 592 // objects during evac failure handling. 593 void note_self_forwarding_removal_end(bool during_initial_mark, 594 bool during_conc_mark, 595 size_t marked_bytes); 596 597 // Returns "false" iff no object in the region was allocated when the 598 // last mark phase ended. 599 bool is_marked() { return _prev_top_at_mark_start != bottom(); } 600 601 void reset_during_compaction() { 602 assert(is_starts_humongous(), 603 "should only be called for starts humongous regions"); 604 605 zero_marked_bytes(); 606 init_top_at_mark_start(); 607 } 608 609 void calc_gc_efficiency(void); 610 double gc_efficiency() { return _gc_efficiency;} 611 612 int young_index_in_cset() const { return _young_index_in_cset; } 613 void set_young_index_in_cset(int index) { 614 assert( (index == -1) || is_young(), "pre-condition" ); 615 _young_index_in_cset = index; 616 } 617 618 int age_in_surv_rate_group() { 619 assert( _surv_rate_group != NULL, "pre-condition" ); 620 assert( _age_index > -1, "pre-condition" ); 621 return _surv_rate_group->age_in_group(_age_index); 622 } 623 624 void record_surv_words_in_group(size_t words_survived) { 625 assert( _surv_rate_group != NULL, "pre-condition" ); 626 assert( _age_index > -1, "pre-condition" ); 627 int age_in_group = age_in_surv_rate_group(); 628 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 629 } 630 631 int age_in_surv_rate_group_cond() { 632 if (_surv_rate_group != NULL) 633 return age_in_surv_rate_group(); 634 else 635 return -1; 636 } 637 638 SurvRateGroup* surv_rate_group() { 639 return _surv_rate_group; 640 } 641 642 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 643 assert( surv_rate_group != NULL, "pre-condition" ); 644 assert( _surv_rate_group == NULL, "pre-condition" ); 645 assert( is_young(), "pre-condition" ); 646 647 _surv_rate_group = surv_rate_group; 648 _age_index = surv_rate_group->next_age_index(); 649 } 650 651 void uninstall_surv_rate_group() { 652 if (_surv_rate_group != NULL) { 653 assert( _age_index > -1, "pre-condition" ); 654 assert( is_young(), "pre-condition" ); 655 656 _surv_rate_group = NULL; 657 _age_index = -1; 658 } else { 659 assert( _age_index == -1, "pre-condition" ); 660 } 661 } 662 663 void set_free() { _type.set_free(); } 664 665 void set_eden() { _type.set_eden(); } 666 void set_eden_pre_gc() { _type.set_eden_pre_gc(); } 667 void set_survivor() { _type.set_survivor(); } 668 669 void set_old() { _type.set_old(); } 670 671 // Determine if an object has been allocated since the last 672 // mark performed by the collector. This returns true iff the object 673 // is within the unmarked area of the region. 674 bool obj_allocated_since_prev_marking(oop obj) const { 675 return (HeapWord *) obj >= prev_top_at_mark_start(); 676 } 677 bool obj_allocated_since_next_marking(oop obj) const { 678 return (HeapWord *) obj >= next_top_at_mark_start(); 679 } 680 681 // Returns the "evacuation_failed" property of the region. 682 bool evacuation_failed() { return _evacuation_failed; } 683 684 // Sets the "evacuation_failed" property of the region. 685 void set_evacuation_failed(bool b) { 686 _evacuation_failed = b; 687 688 if (b) { 689 _next_marked_bytes = 0; 690 } 691 } 692 693 // Requires that "mr" be entirely within the region. 694 // Apply "cl->do_object" to all objects that intersect with "mr". 695 // If the iteration encounters an unparseable portion of the region, 696 // or if "cl->abort()" is true after a closure application, 697 // terminate the iteration and return the address of the start of the 698 // subregion that isn't done. (The two can be distinguished by querying 699 // "cl->abort()".) Return of "NULL" indicates that the iteration 700 // completed. 701 HeapWord* 702 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl); 703 704 // filter_young: if true and the region is a young region then we 705 // skip the iteration. 706 // card_ptr: if not NULL, and we decide that the card is not young 707 // and we iterate over it, we'll clean the card before we start the 708 // iteration. 709 HeapWord* 710 oops_on_card_seq_iterate_careful(MemRegion mr, 711 FilterOutOfRegionClosure* cl, 712 bool filter_young, 713 jbyte* card_ptr); 714 715 size_t recorded_rs_length() const { return _recorded_rs_length; } 716 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 717 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; } 718 719 void set_recorded_rs_length(size_t rs_length) { 720 _recorded_rs_length = rs_length; 721 } 722 723 void set_predicted_elapsed_time_ms(double ms) { 724 _predicted_elapsed_time_ms = ms; 725 } 726 727 void set_predicted_bytes_to_copy(size_t bytes) { 728 _predicted_bytes_to_copy = bytes; 729 } 730 731 virtual CompactibleSpace* next_compaction_space() const; 732 733 virtual void reset_after_compaction(); 734 735 // Routines for managing a list of code roots (attached to the 736 // this region's RSet) that point into this heap region. 737 void add_strong_code_root(nmethod* nm); 738 void add_strong_code_root_locked(nmethod* nm); 739 void remove_strong_code_root(nmethod* nm); 740 741 // Applies blk->do_code_blob() to each of the entries in 742 // the strong code roots list for this region 743 void strong_code_roots_do(CodeBlobClosure* blk) const; 744 745 // Verify that the entries on the strong code root list for this 746 // region are live and include at least one pointer into this region. 747 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 748 749 void print() const; 750 void print_on(outputStream* st) const; 751 752 // vo == UsePrevMarking -> use "prev" marking information, 753 // vo == UseNextMarking -> use "next" marking information 754 // vo == UseMarkWord -> use the mark word in the object header 755 // 756 // NOTE: Only the "prev" marking information is guaranteed to be 757 // consistent most of the time, so most calls to this should use 758 // vo == UsePrevMarking. 759 // Currently, there is only one case where this is called with 760 // vo == UseNextMarking, which is to verify the "next" marking 761 // information at the end of remark. 762 // Currently there is only one place where this is called with 763 // vo == UseMarkWord, which is to verify the marking during a 764 // full GC. 765 void verify(VerifyOption vo, bool *failures) const; 766 767 // Override; it uses the "prev" marking information 768 virtual void verify() const; 769 }; 770 771 // HeapRegionClosure is used for iterating over regions. 772 // Terminates the iteration when the "doHeapRegion" method returns "true". 773 class HeapRegionClosure : public StackObj { 774 friend class HeapRegionManager; 775 friend class G1CollectedHeap; 776 777 bool _complete; 778 void incomplete() { _complete = false; } 779 780 public: 781 HeapRegionClosure(): _complete(true) {} 782 783 // Typically called on each region until it returns true. 784 virtual bool doHeapRegion(HeapRegion* r) = 0; 785 786 // True after iteration if the closure was applied to all heap regions 787 // and returned "false" in all cases. 788 bool complete() { return _complete; } 789 }; 790 791 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP