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