1 /* 2 * Copyright (c) 2001, 2019, 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_GC_G1_HEAPREGION_HPP 26 #define SHARE_GC_G1_HEAPREGION_HPP 27 28 #include "gc/g1/g1BlockOffsetTable.hpp" 29 #include "gc/g1/g1HeapRegionTraceType.hpp" 30 #include "gc/g1/heapRegionTracer.hpp" 31 #include "gc/g1/heapRegionType.hpp" 32 #include "gc/g1/survRateGroup.hpp" 33 #include "gc/shared/ageTable.hpp" 34 #include "gc/shared/spaceDecorator.hpp" 35 #include "gc/shared/verifyOption.hpp" 36 #include "runtime/mutex.hpp" 37 #include "utilities/macros.hpp" 38 39 class G1CollectedHeap; 40 class G1CMBitMap; 41 class HeapRegionRemSet; 42 class HeapRegion; 43 class HeapRegionSetBase; 44 class nmethod; 45 46 #define HR_FORMAT "%u:(%s)[" PTR_FORMAT "," PTR_FORMAT "," PTR_FORMAT "]" 47 #define HR_FORMAT_PARAMS(_hr_) \ 48 (_hr_)->hrm_index(), \ 49 (_hr_)->get_short_type_str(), \ 50 p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end()) 51 52 // sentinel value for hrm_index 53 #define G1_NO_HRM_INDEX ((uint) -1) 54 55 // A HeapRegion is the smallest piece of a G1CollectedHeap that 56 // can be collected independently. 57 58 // Each heap region is self contained. top() and end() can never 59 // be set beyond the end of the region. For humongous objects, 60 // the first region is a StartsHumongous region. If the humongous 61 // object is larger than a heap region, the following regions will 62 // be of type ContinuesHumongous. In this case the top() of the 63 // StartHumongous region and all ContinuesHumongous regions except 64 // the last will point to their own end. The last ContinuesHumongous 65 // region may have top() equal the end of object if there isn't 66 // room for filler objects to pad out to the end of the region. 67 class HeapRegion : public CHeapObj<mtGC> { 68 friend class VMStructs; 69 70 HeapWord* const _bottom; 71 HeapWord* const _end; 72 73 HeapWord* volatile _top; 74 HeapWord* _compaction_top; 75 76 G1BlockOffsetTablePart _bot_part; 77 Mutex _par_alloc_lock; 78 // When we need to retire an allocation region, while other threads 79 // are also concurrently trying to allocate into it, we typically 80 // allocate a dummy object at the end of the region to ensure that 81 // no more allocations can take place in it. However, sometimes we 82 // want to know where the end of the last "real" object we allocated 83 // into the region was and this is what this keeps track. 84 HeapWord* _pre_dummy_top; 85 86 public: 87 HeapWord* bottom() const { return _bottom; } 88 HeapWord* end() const { return _end; } 89 90 void set_compaction_top(HeapWord* compaction_top) { _compaction_top = compaction_top; } 91 HeapWord* compaction_top() const { return _compaction_top; } 92 93 void set_top(HeapWord* value) { _top = value; } 94 HeapWord* top() const { return _top; } 95 96 // See the comment above in the declaration of _pre_dummy_top for an 97 // explanation of what it is. 98 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 99 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 100 _pre_dummy_top = pre_dummy_top; 101 } 102 HeapWord* pre_dummy_top() { return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; } 103 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 104 105 // Returns true iff the given the heap region contains the 106 // given address as part of an allocated object. This may 107 // be a potentially, so we restrict its use to assertion checks only. 108 bool is_in(const void* p) const { 109 return is_in_reserved(p); 110 } 111 bool is_in(oop obj) const { 112 return is_in((void*)obj); 113 } 114 // Returns true iff the given reserved memory of the space contains the 115 // given address. 116 bool is_in_reserved(const void* p) const { return _bottom <= p && p < _end; } 117 118 size_t capacity() const { return byte_size(bottom(), end()); } 119 size_t used() const { return byte_size(bottom(), top()); } 120 size_t free() const { return byte_size(top(), end()); } 121 122 bool is_empty() const { return used() == 0; } 123 124 private: 125 void reset_after_compaction() { set_top(compaction_top()); } 126 127 void clear(bool mangle_space); 128 129 HeapWord* block_start_const(const void* p) const; 130 131 void mangle_unused_area() PRODUCT_RETURN; 132 133 // Try to allocate at least min_word_size and up to desired_size from this region. 134 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 135 // space allocated. 136 // This version assumes that all allocation requests to this HeapRegion are properly 137 // synchronized. 138 inline HeapWord* allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 139 // Try to allocate at least min_word_size and up to desired_size from this HeapRegion. 140 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 141 // space allocated. 142 // This version synchronizes with other calls to par_allocate_impl(). 143 inline HeapWord* par_allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 144 145 public: 146 HeapWord* block_start(const void* p); 147 148 void object_iterate(ObjectClosure* blk); 149 150 // Allocation (return NULL if full). Assumes the caller has established 151 // mutually exclusive access to the HeapRegion. 152 HeapWord* allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 153 // Allocation (return NULL if full). Enforces mutual exclusion internally. 154 HeapWord* par_allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 155 156 HeapWord* allocate(size_t word_size); 157 HeapWord* par_allocate(size_t word_size); 158 159 inline HeapWord* par_allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* word_size); 160 inline HeapWord* allocate_no_bot_updates(size_t word_size); 161 inline HeapWord* allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* actual_size); 162 163 // Full GC support methods. 164 165 HeapWord* initialize_threshold(); 166 HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 167 // Update heap region to be consistent after Full GC compaction. 168 void reset_humongous_during_compaction() { 169 assert(is_humongous(), 170 "should only be called for humongous regions"); 171 172 zero_marked_bytes(); 173 init_top_at_mark_start(); 174 } 175 // Update heap region to be consistent after Full GC compaction. 176 void complete_compaction(); 177 178 // All allocated blocks are occupied by objects in a HeapRegion 179 bool block_is_obj(const HeapWord* p) const; 180 181 // Returns whether the given object is dead based on TAMS and bitmap. 182 bool is_obj_dead(const oop obj, const G1CMBitMap* const prev_bitmap) const; 183 184 // Returns the object size for all valid block starts 185 // and the amount of unallocated words if called on top() 186 size_t block_size(const HeapWord* p) const; 187 188 // Scans through the region using the bitmap to determine what 189 // objects to call size_t ApplyToMarkedClosure::apply(oop) for. 190 template<typename ApplyToMarkedClosure> 191 inline void apply_to_marked_objects(G1CMBitMap* bitmap, ApplyToMarkedClosure* closure); 192 193 void reset_bot() { 194 _bot_part.reset_bot(); 195 } 196 197 private: 198 // The remembered set for this region. 199 HeapRegionRemSet* _rem_set; 200 201 // Cached index of this region in the heap region sequence. 202 const uint _hrm_index; 203 204 HeapRegionType _type; 205 206 // For a humongous region, region in which it starts. 207 HeapRegion* _humongous_start_region; 208 209 // True iff an attempt to evacuate an object in the region failed. 210 bool _evacuation_failed; 211 212 static const uint InvalidCSetIndex = UINT_MAX; 213 214 // The index in the optional regions array, if this region 215 // is considered optional during a mixed collections. 216 uint _index_in_opt_cset; 217 218 // Fields used by the HeapRegionSetBase class and subclasses. 219 HeapRegion* _next; 220 HeapRegion* _prev; 221 #ifdef ASSERT 222 HeapRegionSetBase* _containing_set; 223 #endif // ASSERT 224 225 // The start of the unmarked area. The unmarked area extends from this 226 // word until the top and/or end of the region, and is the part 227 // of the region for which no marking was done, i.e. objects may 228 // have been allocated in this part since the last mark phase. 229 // "prev" is the top at the start of the last completed marking. 230 // "next" is the top at the start of the in-progress marking (if any.) 231 HeapWord* _prev_top_at_mark_start; 232 HeapWord* _next_top_at_mark_start; 233 234 // We use concurrent marking to determine the amount of live data 235 // in each heap region. 236 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 237 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 238 239 void init_top_at_mark_start() { 240 assert(_prev_marked_bytes == 0 && 241 _next_marked_bytes == 0, 242 "Must be called after zero_marked_bytes."); 243 _prev_top_at_mark_start = _next_top_at_mark_start = bottom(); 244 } 245 246 // Data for young region survivor prediction. 247 uint _young_index_in_cset; 248 SurvRateGroup* _surv_rate_group; 249 int _age_index; 250 251 // Cached attributes used in the collection set policy information 252 253 // The calculated GC efficiency of the region. 254 double _gc_efficiency; 255 256 // The remembered set length that was added to the total value 257 // for the collection set. 258 size_t _recorded_rs_length; 259 260 // The predicted elapsed time that was added to total value 261 // for the collection set. 262 double _predicted_elapsed_time_ms; 263 264 uint _node_index; 265 266 void report_region_type_change(G1HeapRegionTraceType::Type to); 267 268 // Returns whether the given object address refers to a dead object, and either the 269 // size of the object (if live) or the size of the block (if dead) in size. 270 // May 271 // - only called with obj < top() 272 // - not called on humongous objects or archive regions 273 inline bool is_obj_dead_with_size(const oop obj, const G1CMBitMap* const prev_bitmap, size_t* size) const; 274 275 // Iterate over the references covered by the given MemRegion in a humongous 276 // object and apply the given closure to them. 277 // Humongous objects are allocated directly in the old-gen. So we need special 278 // handling for concurrent processing encountering an in-progress allocation. 279 // Returns the address after the last actually scanned or NULL if the area could 280 // not be scanned (That should only happen when invoked concurrently with the 281 // mutator). 282 template <class Closure, bool is_gc_active> 283 inline HeapWord* do_oops_on_memregion_in_humongous(MemRegion mr, 284 Closure* cl, 285 G1CollectedHeap* g1h); 286 287 // Returns the block size of the given (dead, potentially having its class unloaded) object 288 // starting at p extending to at most the prev TAMS using the given mark bitmap. 289 inline size_t block_size_using_bitmap(const HeapWord* p, const G1CMBitMap* const prev_bitmap) const; 290 public: 291 HeapRegion(uint hrm_index, G1BlockOffsetTable* bot, MemRegion mr); 292 293 // If this region is a member of a HeapRegionManager, the index in that 294 // sequence, otherwise -1. 295 uint hrm_index() const { return _hrm_index; } 296 297 // Initializing the HeapRegion not only resets the data structure, but also 298 // resets the BOT for that heap region. 299 // The default values for clear_space means that we will do the clearing if 300 // there's clearing to be done ourselves. We also always mangle the space. 301 void initialize(bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 302 303 static int LogOfHRGrainBytes; 304 static int LogOfHRGrainWords; 305 static int LogCardsPerRegion; 306 307 static size_t GrainBytes; 308 static size_t GrainWords; 309 static size_t CardsPerRegion; 310 311 static size_t align_up_to_region_byte_size(size_t sz) { 312 return (sz + (size_t) GrainBytes - 1) & 313 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 314 } 315 316 // Returns whether a field is in the same region as the obj it points to. 317 template <typename T> 318 static bool is_in_same_region(T* p, oop obj) { 319 assert(p != NULL, "p can't be NULL"); 320 assert(obj != NULL, "obj can't be NULL"); 321 return (((uintptr_t) p ^ cast_from_oop<uintptr_t>(obj)) >> LogOfHRGrainBytes) == 0; 322 } 323 324 static size_t max_region_size(); 325 static size_t min_region_size_in_words(); 326 327 // It sets up the heap region size (GrainBytes / GrainWords), as 328 // well as other related fields that are based on the heap region 329 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 330 // CardsPerRegion). All those fields are considered constant 331 // throughout the JVM's execution, therefore they should only be set 332 // up once during initialization time. 333 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 334 335 // The number of bytes marked live in the region in the last marking phase. 336 size_t marked_bytes() { return _prev_marked_bytes; } 337 size_t live_bytes() { 338 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 339 } 340 341 // The number of bytes counted in the next marking. 342 size_t next_marked_bytes() { return _next_marked_bytes; } 343 // The number of bytes live wrt the next marking. 344 size_t next_live_bytes() { 345 return 346 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 347 } 348 349 // A lower bound on the amount of garbage bytes in the region. 350 size_t garbage_bytes() { 351 size_t used_at_mark_start_bytes = 352 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 353 return used_at_mark_start_bytes - marked_bytes(); 354 } 355 356 // Return the amount of bytes we'll reclaim if we collect this 357 // region. This includes not only the known garbage bytes in the 358 // region but also any unallocated space in it, i.e., [top, end), 359 // since it will also be reclaimed if we collect the region. 360 size_t reclaimable_bytes() { 361 size_t known_live_bytes = live_bytes(); 362 assert(known_live_bytes <= capacity(), "sanity"); 363 return capacity() - known_live_bytes; 364 } 365 366 // An upper bound on the number of live bytes in the region. 367 size_t max_live_bytes() { return used() - garbage_bytes(); } 368 369 void add_to_marked_bytes(size_t incr_bytes) { 370 _next_marked_bytes = _next_marked_bytes + incr_bytes; 371 } 372 373 void zero_marked_bytes() { 374 _prev_marked_bytes = _next_marked_bytes = 0; 375 } 376 // Get the start of the unmarked area in this region. 377 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 378 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 379 380 // Note the start or end of marking. This tells the heap region 381 // that the collector is about to start or has finished (concurrently) 382 // marking the heap. 383 384 // Notify the region that concurrent marking is starting. Initialize 385 // all fields related to the next marking info. 386 inline void note_start_of_marking(); 387 388 // Notify the region that concurrent marking has finished. Copy the 389 // (now finalized) next marking info fields into the prev marking 390 // info fields. 391 inline void note_end_of_marking(); 392 393 const char* get_type_str() const { return _type.get_str(); } 394 const char* get_short_type_str() const { return _type.get_short_str(); } 395 G1HeapRegionTraceType::Type get_trace_type() { return _type.get_trace_type(); } 396 397 bool is_free() const { return _type.is_free(); } 398 399 bool is_young() const { return _type.is_young(); } 400 bool is_eden() const { return _type.is_eden(); } 401 bool is_survivor() const { return _type.is_survivor(); } 402 403 bool is_humongous() const { return _type.is_humongous(); } 404 bool is_starts_humongous() const { return _type.is_starts_humongous(); } 405 bool is_continues_humongous() const { return _type.is_continues_humongous(); } 406 407 bool is_old() const { return _type.is_old(); } 408 409 bool is_old_or_humongous() const { return _type.is_old_or_humongous(); } 410 411 bool is_old_or_humongous_or_archive() const { return _type.is_old_or_humongous_or_archive(); } 412 413 // A pinned region contains objects which are not moved by garbage collections. 414 // Humongous regions and archive regions are pinned. 415 bool is_pinned() const { return _type.is_pinned(); } 416 417 // An archive region is a pinned region, also tagged as old, which 418 // should not be marked during mark/sweep. This allows the address 419 // space to be shared by JVM instances. 420 bool is_archive() const { return _type.is_archive(); } 421 bool is_open_archive() const { return _type.is_open_archive(); } 422 bool is_closed_archive() const { return _type.is_closed_archive(); } 423 424 void set_free(); 425 426 void set_eden(); 427 void set_eden_pre_gc(); 428 void set_survivor(); 429 430 void move_to_old(); 431 void set_old(); 432 433 void set_open_archive(); 434 void set_closed_archive(); 435 436 // For a humongous region, region in which it starts. 437 HeapRegion* humongous_start_region() const { 438 return _humongous_start_region; 439 } 440 441 // Makes the current region be a "starts humongous" region, i.e., 442 // the first region in a series of one or more contiguous regions 443 // that will contain a single "humongous" object. 444 // 445 // obj_top : points to the top of the humongous object. 446 // fill_size : size of the filler object at the end of the region series. 447 void set_starts_humongous(HeapWord* obj_top, size_t fill_size); 448 449 // Makes the current region be a "continues humongous' 450 // region. first_hr is the "start humongous" region of the series 451 // which this region will be part of. 452 void set_continues_humongous(HeapRegion* first_hr); 453 454 // Unsets the humongous-related fields on the region. 455 void clear_humongous(); 456 457 // If the region has a remembered set, return a pointer to it. 458 HeapRegionRemSet* rem_set() const { 459 return _rem_set; 460 } 461 462 inline bool in_collection_set() const; 463 464 // Methods used by the HeapRegionSetBase class and subclasses. 465 466 // Getter and setter for the next and prev fields used to link regions into 467 // linked lists. 468 void set_next(HeapRegion* next) { _next = next; } 469 HeapRegion* next() { return _next; } 470 471 void set_prev(HeapRegion* prev) { _prev = prev; } 472 HeapRegion* prev() { return _prev; } 473 474 // Every region added to a set is tagged with a reference to that 475 // set. This is used for doing consistency checking to make sure that 476 // the contents of a set are as they should be and it's only 477 // available in non-product builds. 478 #ifdef ASSERT 479 void set_containing_set(HeapRegionSetBase* containing_set) { 480 assert((containing_set == NULL && _containing_set != NULL) || 481 (containing_set != NULL && _containing_set == NULL), 482 "containing_set: " PTR_FORMAT " " 483 "_containing_set: " PTR_FORMAT, 484 p2i(containing_set), p2i(_containing_set)); 485 486 _containing_set = containing_set; 487 } 488 489 HeapRegionSetBase* containing_set() { return _containing_set; } 490 #else // ASSERT 491 void set_containing_set(HeapRegionSetBase* containing_set) { } 492 493 // containing_set() is only used in asserts so there's no reason 494 // to provide a dummy version of it. 495 #endif // ASSERT 496 497 498 // Reset the HeapRegion to default values. 499 // If skip_remset is true, do not clear the remembered set. 500 // If clear_space is true, clear the HeapRegion's memory. 501 // If locked is true, assume we are the only thread doing this operation. 502 void hr_clear(bool skip_remset, bool clear_space, bool locked = false); 503 // Clear the card table corresponding to this region. 504 void clear_cardtable(); 505 506 // Returns the "evacuation_failed" property of the region. 507 bool evacuation_failed() { return _evacuation_failed; } 508 509 // Sets the "evacuation_failed" property of the region. 510 void set_evacuation_failed(bool b) { 511 _evacuation_failed = b; 512 513 if (b) { 514 _next_marked_bytes = 0; 515 } 516 } 517 518 // Notify the region that we are about to start processing 519 // self-forwarded objects during evac failure handling. 520 void note_self_forwarding_removal_start(bool during_initial_mark, 521 bool during_conc_mark); 522 523 // Notify the region that we have finished processing self-forwarded 524 // objects during evac failure handling. 525 void note_self_forwarding_removal_end(size_t marked_bytes); 526 527 uint index_in_opt_cset() const { 528 assert(has_index_in_opt_cset(), "Opt cset index not set."); 529 return _index_in_opt_cset; 530 } 531 bool has_index_in_opt_cset() const { return _index_in_opt_cset != InvalidCSetIndex; } 532 void set_index_in_opt_cset(uint index) { _index_in_opt_cset = index; } 533 void clear_index_in_opt_cset() { _index_in_opt_cset = InvalidCSetIndex; } 534 535 void calc_gc_efficiency(void); 536 double gc_efficiency() const { return _gc_efficiency;} 537 538 uint young_index_in_cset() const { return _young_index_in_cset; } 539 void clear_young_index_in_cset() { _young_index_in_cset = 0; } 540 void set_young_index_in_cset(uint index) { 541 assert(index != UINT_MAX, "just checking"); 542 assert(index != 0, "just checking"); 543 assert(is_young(), "pre-condition"); 544 _young_index_in_cset = index; 545 } 546 547 int age_in_surv_rate_group() { 548 assert(_surv_rate_group != NULL, "pre-condition"); 549 assert(_age_index > -1, "pre-condition"); 550 return _surv_rate_group->age_in_group(_age_index); 551 } 552 553 void record_surv_words_in_group(size_t words_survived) { 554 assert(_surv_rate_group != NULL, "pre-condition"); 555 assert(_age_index > -1, "pre-condition"); 556 int age_in_group = age_in_surv_rate_group(); 557 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 558 } 559 560 int age_in_surv_rate_group_cond() { 561 if (_surv_rate_group != NULL) 562 return age_in_surv_rate_group(); 563 else 564 return -1; 565 } 566 567 SurvRateGroup* surv_rate_group() { 568 return _surv_rate_group; 569 } 570 571 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 572 assert(surv_rate_group != NULL, "pre-condition"); 573 assert(_surv_rate_group == NULL, "pre-condition"); 574 assert(is_young(), "pre-condition"); 575 576 _surv_rate_group = surv_rate_group; 577 _age_index = surv_rate_group->next_age_index(); 578 } 579 580 void uninstall_surv_rate_group() { 581 if (_surv_rate_group != NULL) { 582 assert(_age_index > -1, "pre-condition"); 583 assert(is_young(), "pre-condition"); 584 585 _surv_rate_group = NULL; 586 _age_index = -1; 587 } else { 588 assert(_age_index == -1, "pre-condition"); 589 } 590 } 591 592 // Determine if an object has been allocated since the last 593 // mark performed by the collector. This returns true iff the object 594 // is within the unmarked area of the region. 595 bool obj_allocated_since_prev_marking(oop obj) const { 596 return (HeapWord *) obj >= prev_top_at_mark_start(); 597 } 598 bool obj_allocated_since_next_marking(oop obj) const { 599 return (HeapWord *) obj >= next_top_at_mark_start(); 600 } 601 602 // Iterate over the objects overlapping the given memory region, applying cl 603 // to all references in the region. This is a helper for 604 // G1RemSet::refine_card*, and is tightly coupled with them. 605 // mr must not be empty. Must be trimmed to the allocated/parseable space in this region. 606 // This region must be old or humongous. 607 // Returns the next unscanned address if the designated objects were successfully 608 // processed, NULL if an unparseable part of the heap was encountered (That should 609 // only happen when invoked concurrently with the mutator). 610 template <bool is_gc_active, class Closure> 611 inline HeapWord* oops_on_memregion_seq_iterate_careful(MemRegion mr, Closure* cl); 612 613 size_t recorded_rs_length() const { return _recorded_rs_length; } 614 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 615 616 void set_recorded_rs_length(size_t rs_length) { 617 _recorded_rs_length = rs_length; 618 } 619 620 void set_predicted_elapsed_time_ms(double ms) { 621 _predicted_elapsed_time_ms = ms; 622 } 623 624 // Routines for managing a list of code roots (attached to the 625 // this region's RSet) that point into this heap region. 626 void add_strong_code_root(nmethod* nm); 627 void add_strong_code_root_locked(nmethod* nm); 628 void remove_strong_code_root(nmethod* nm); 629 630 // Applies blk->do_code_blob() to each of the entries in 631 // the strong code roots list for this region 632 void strong_code_roots_do(CodeBlobClosure* blk) const; 633 634 uint node_index() const { return _node_index; } 635 void set_node_index(uint node_index) { _node_index = node_index; } 636 637 // Verify that the entries on the strong code root list for this 638 // region are live and include at least one pointer into this region. 639 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 640 641 void print() const; 642 void print_on(outputStream* st) const; 643 644 // vo == UsePrevMarking -> use "prev" marking information, 645 // vo == UseNextMarking -> use "next" marking information 646 // vo == UseFullMarking -> use "next" marking bitmap but no TAMS 647 // 648 // NOTE: Only the "prev" marking information is guaranteed to be 649 // consistent most of the time, so most calls to this should use 650 // vo == UsePrevMarking. 651 // Currently, there is only one case where this is called with 652 // vo == UseNextMarking, which is to verify the "next" marking 653 // information at the end of remark. 654 // Currently there is only one place where this is called with 655 // vo == UseFullMarking, which is to verify the marking during a 656 // full GC. 657 void verify(VerifyOption vo, bool *failures) const; 658 659 // Verify using the "prev" marking information 660 void verify() const; 661 662 void verify_rem_set(VerifyOption vo, bool *failures) const; 663 void verify_rem_set() const; 664 }; 665 666 // HeapRegionClosure is used for iterating over regions. 667 // Terminates the iteration when the "do_heap_region" method returns "true". 668 class HeapRegionClosure : public StackObj { 669 friend class HeapRegionManager; 670 friend class G1CollectionSet; 671 friend class G1CollectionSetCandidates; 672 673 bool _is_complete; 674 void set_incomplete() { _is_complete = false; } 675 676 public: 677 HeapRegionClosure(): _is_complete(true) {} 678 679 // Typically called on each region until it returns true. 680 virtual bool do_heap_region(HeapRegion* r) = 0; 681 682 // True after iteration if the closure was applied to all heap regions 683 // and returned "false" in all cases. 684 bool is_complete() { return _is_complete; } 685 }; 686 687 #endif // SHARE_GC_G1_HEAPREGION_HPP