1 /* 2 * Copyright (c) 2001, 2015, 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_G1_HEAPREGION_HPP 26 #define SHARE_VM_GC_G1_HEAPREGION_HPP 27 28 #include "gc/g1/g1AllocationContext.hpp" 29 #include "gc/g1/g1BlockOffsetTable.hpp" 30 #include "gc/g1/heapRegionType.hpp" 31 #include "gc/g1/survRateGroup.hpp" 32 #include "gc/shared/ageTable.hpp" 33 #include "gc/shared/spaceDecorator.hpp" 34 #include "utilities/macros.hpp" 35 36 // A HeapRegion is the smallest piece of a G1CollectedHeap that 37 // can be collected independently. 38 39 // NOTE: Although a HeapRegion is a Space, its 40 // Space::initDirtyCardClosure method must not be called. 41 // The problem is that the existence of this method breaks 42 // the independence of barrier sets from remembered sets. 43 // The solution is to remove this method from the definition 44 // of a Space. 45 46 // Each heap region is self contained. top() and end() can never 47 // be set beyond the end of the region. For humongous objects, 48 // the first region is a StartsHumongous region. If the humongous 49 // object is larger than a heap region, the following regions will 50 // be of type ContinuesHumongous. In this case the top() of the 51 // StartHumongous region and all ContinuesHumongous regions except 52 // the last will point to their own end. For the last ContinuesHumongous 53 // region, top() will equal the object's top. 54 55 class G1CollectedHeap; 56 class HeapRegionRemSet; 57 class HeapRegionRemSetIterator; 58 class HeapRegion; 59 class HeapRegionSetBase; 60 class nmethod; 61 62 #define HR_FORMAT "%u:(%s)[" PTR_FORMAT "," PTR_FORMAT "," PTR_FORMAT "]" 63 #define HR_FORMAT_PARAMS(_hr_) \ 64 (_hr_)->hrm_index(), \ 65 (_hr_)->get_short_type_str(), \ 66 p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end()) 67 68 // sentinel value for hrm_index 69 #define G1_NO_HRM_INDEX ((uint) -1) 70 71 // A dirty card to oop closure for heap regions. It 72 // knows how to get the G1 heap and how to use the bitmap 73 // in the concurrent marker used by G1 to filter remembered 74 // sets. 75 76 class HeapRegionDCTOC : public DirtyCardToOopClosure { 77 private: 78 HeapRegion* _hr; 79 G1ParPushHeapRSClosure* _rs_scan; 80 G1CollectedHeap* _g1; 81 82 // Walk the given memory region from bottom to (actual) top 83 // looking for objects and applying the oop closure (_cl) to 84 // them. The base implementation of this treats the area as 85 // blocks, where a block may or may not be an object. Sub- 86 // classes should override this to provide more accurate 87 // or possibly more efficient walking. 88 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top); 89 90 public: 91 HeapRegionDCTOC(G1CollectedHeap* g1, 92 HeapRegion* hr, 93 G1ParPushHeapRSClosure* cl, 94 CardTableModRefBS::PrecisionStyle precision); 95 }; 96 97 // The complicating factor is that BlockOffsetTable diverged 98 // significantly, and we need functionality that is only in the G1 version. 99 // So I copied that code, which led to an alternate G1 version of 100 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could 101 // be reconciled, then G1OffsetTableContigSpace could go away. 102 103 // The idea behind time stamps is the following. We want to keep track of 104 // the highest address where it's safe to scan objects for each region. 105 // This is only relevant for current GC alloc regions so we keep a time stamp 106 // per region to determine if the region has been allocated during the current 107 // GC or not. If the time stamp is current we report a scan_top value which 108 // was saved at the end of the previous GC for retained alloc regions and which is 109 // equal to the bottom for all other regions. 110 // There is a race between card scanners and allocating gc workers where we must ensure 111 // that card scanners do not read the memory allocated by the gc workers. 112 // In order to enforce that, we must not return a value of _top which is more recent than the 113 // time stamp. This is due to the fact that a region may become a gc alloc region at 114 // some point after we've read the timestamp value as being < the current time stamp. 115 // The time stamps are re-initialized to zero at cleanup and at Full GCs. 116 // The current scheme that uses sequential unsigned ints will fail only if we have 4b 117 // evacuation pauses between two cleanups, which is _highly_ unlikely. 118 class G1ContiguousSpace: public CompactibleSpace { 119 friend class VMStructs; 120 HeapWord* volatile _top; 121 HeapWord* volatile _scan_top; 122 protected: 123 G1BlockOffsetTablePart _bot_part; 124 Mutex _par_alloc_lock; 125 volatile unsigned _gc_time_stamp; 126 // When we need to retire an allocation region, while other threads 127 // are also concurrently trying to allocate into it, we typically 128 // allocate a dummy object at the end of the region to ensure that 129 // no more allocations can take place in it. However, sometimes we 130 // want to know where the end of the last "real" object we allocated 131 // into the region was and this is what this keeps track. 132 HeapWord* _pre_dummy_top; 133 134 public: 135 G1ContiguousSpace(G1BlockOffsetTable* bot); 136 137 void set_top(HeapWord* value) { _top = value; } 138 HeapWord* top() const { return _top; } 139 140 protected: 141 // Reset the G1ContiguousSpace. 142 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); 143 144 HeapWord* volatile* top_addr() { return &_top; } 145 // Try to allocate at least min_word_size and up to desired_size from this Space. 146 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 147 // space allocated. 148 // This version assumes that all allocation requests to this Space are properly 149 // synchronized. 150 inline HeapWord* allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 151 // Try to allocate at least min_word_size and up to desired_size from this Space. 152 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 153 // space allocated. 154 // This version synchronizes with other calls to par_allocate_impl(). 155 inline HeapWord* par_allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 156 157 public: 158 void reset_after_compaction() { set_top(compaction_top()); } 159 160 size_t used() const { return byte_size(bottom(), top()); } 161 size_t free() const { return byte_size(top(), end()); } 162 bool is_free_block(const HeapWord* p) const { return p >= top(); } 163 164 MemRegion used_region() const { return MemRegion(bottom(), top()); } 165 166 void object_iterate(ObjectClosure* blk); 167 void safe_object_iterate(ObjectClosure* blk); 168 169 void mangle_unused_area() PRODUCT_RETURN; 170 void mangle_unused_area_complete() PRODUCT_RETURN; 171 172 HeapWord* scan_top() const; 173 void record_timestamp(); 174 void reset_gc_time_stamp() { _gc_time_stamp = 0; } 175 unsigned get_gc_time_stamp() { return _gc_time_stamp; } 176 void record_retained_region(); 177 178 // See the comment above in the declaration of _pre_dummy_top for an 179 // explanation of what it is. 180 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 181 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 182 _pre_dummy_top = pre_dummy_top; 183 } 184 HeapWord* pre_dummy_top() { 185 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; 186 } 187 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 188 189 virtual void clear(bool mangle_space); 190 191 HeapWord* block_start(const void* p); 192 HeapWord* block_start_const(const void* p) const; 193 194 // Allocation (return NULL if full). Assumes the caller has established 195 // mutually exclusive access to the space. 196 HeapWord* allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 197 // Allocation (return NULL if full). Enforces mutual exclusion internally. 198 HeapWord* par_allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 199 200 virtual HeapWord* allocate(size_t word_size); 201 virtual HeapWord* par_allocate(size_t word_size); 202 203 HeapWord* saved_mark_word() const { ShouldNotReachHere(); return NULL; } 204 205 // MarkSweep support phase3 206 virtual HeapWord* initialize_threshold(); 207 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 208 209 virtual void print() const; 210 211 void reset_bot() { 212 _bot_part.reset_bot(); 213 } 214 215 void print_bot_on(outputStream* out) { 216 _bot_part.print_on(out); 217 } 218 }; 219 220 class HeapRegion: public G1ContiguousSpace { 221 friend class VMStructs; 222 // Allow scan_and_forward to call (private) overrides for auxiliary functions on this class 223 template <typename SpaceType> 224 friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp); 225 private: 226 227 // The remembered set for this region. 228 // (Might want to make this "inline" later, to avoid some alloc failure 229 // issues.) 230 HeapRegionRemSet* _rem_set; 231 232 // Auxiliary functions for scan_and_forward support. 233 // See comments for CompactibleSpace for more information. 234 inline HeapWord* scan_limit() const { 235 return top(); 236 } 237 238 inline bool scanned_block_is_obj(const HeapWord* addr) const { 239 return true; // Always true, since scan_limit is top 240 } 241 242 inline size_t scanned_block_size(const HeapWord* addr) const { 243 return HeapRegion::block_size(addr); // Avoid virtual call 244 } 245 246 protected: 247 // The index of this region in the heap region sequence. 248 uint _hrm_index; 249 250 AllocationContext_t _allocation_context; 251 252 HeapRegionType _type; 253 254 // For a humongous region, region in which it starts. 255 HeapRegion* _humongous_start_region; 256 257 // True iff an attempt to evacuate an object in the region failed. 258 bool _evacuation_failed; 259 260 // A heap region may be a member one of a number of special subsets, each 261 // represented as linked lists through the field below. Currently, there 262 // is only one set: 263 // The collection set. 264 HeapRegion* _next_in_special_set; 265 266 // next region in the young "generation" region set 267 HeapRegion* _next_young_region; 268 269 // Next region whose cards need cleaning 270 HeapRegion* _next_dirty_cards_region; 271 272 // Fields used by the HeapRegionSetBase class and subclasses. 273 HeapRegion* _next; 274 HeapRegion* _prev; 275 #ifdef ASSERT 276 HeapRegionSetBase* _containing_set; 277 #endif // ASSERT 278 279 // We use concurrent marking to determine the amount of live data 280 // in each heap region. 281 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 282 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 283 284 // The calculated GC efficiency of the region. 285 double _gc_efficiency; 286 287 int _young_index_in_cset; 288 SurvRateGroup* _surv_rate_group; 289 int _age_index; 290 291 // The start of the unmarked area. The unmarked area extends from this 292 // word until the top and/or end of the region, and is the part 293 // of the region for which no marking was done, i.e. objects may 294 // have been allocated in this part since the last mark phase. 295 // "prev" is the top at the start of the last completed marking. 296 // "next" is the top at the start of the in-progress marking (if any.) 297 HeapWord* _prev_top_at_mark_start; 298 HeapWord* _next_top_at_mark_start; 299 // If a collection pause is in progress, this is the top at the start 300 // of that pause. 301 302 void init_top_at_mark_start() { 303 assert(_prev_marked_bytes == 0 && 304 _next_marked_bytes == 0, 305 "Must be called after zero_marked_bytes."); 306 HeapWord* bot = bottom(); 307 _prev_top_at_mark_start = bot; 308 _next_top_at_mark_start = bot; 309 } 310 311 // Cached attributes used in the collection set policy information 312 313 // The RSet length that was added to the total value 314 // for the collection set. 315 size_t _recorded_rs_length; 316 317 // The predicted elapsed time that was added to total value 318 // for the collection set. 319 double _predicted_elapsed_time_ms; 320 321 // The predicted number of bytes to copy that was added to 322 // the total value for the collection set. 323 size_t _predicted_bytes_to_copy; 324 325 public: 326 HeapRegion(uint hrm_index, 327 G1BlockOffsetTable* bot, 328 MemRegion mr); 329 330 // Initializing the HeapRegion not only resets the data structure, but also 331 // resets the BOT for that heap region. 332 // The default values for clear_space means that we will do the clearing if 333 // there's clearing to be done ourselves. We also always mangle the space. 334 virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 335 336 static int LogOfHRGrainBytes; 337 static int LogOfHRGrainWords; 338 339 static size_t GrainBytes; 340 static size_t GrainWords; 341 static size_t CardsPerRegion; 342 343 static size_t align_up_to_region_byte_size(size_t sz) { 344 return (sz + (size_t) GrainBytes - 1) & 345 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 346 } 347 348 349 // Returns whether a field is in the same region as the obj it points to. 350 template <typename T> 351 static bool is_in_same_region(T* p, oop obj) { 352 assert(p != NULL, "p can't be NULL"); 353 assert(obj != NULL, "obj can't be NULL"); 354 return (((uintptr_t) p ^ cast_from_oop<uintptr_t>(obj)) >> LogOfHRGrainBytes) == 0; 355 } 356 357 static size_t max_region_size(); 358 static size_t min_region_size_in_words(); 359 360 // It sets up the heap region size (GrainBytes / GrainWords), as 361 // well as other related fields that are based on the heap region 362 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 363 // CardsPerRegion). All those fields are considered constant 364 // throughout the JVM's execution, therefore they should only be set 365 // up once during initialization time. 366 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 367 368 // All allocated blocks are occupied by objects in a HeapRegion 369 bool block_is_obj(const HeapWord* p) const; 370 371 // Returns the object size for all valid block starts 372 // and the amount of unallocated words if called on top() 373 size_t block_size(const HeapWord* p) const; 374 375 // Override for scan_and_forward support. 376 void prepare_for_compaction(CompactPoint* cp); 377 378 inline HeapWord* par_allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* word_size); 379 inline HeapWord* allocate_no_bot_updates(size_t word_size); 380 inline HeapWord* allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* actual_size); 381 382 // If this region is a member of a HeapRegionManager, the index in that 383 // sequence, otherwise -1. 384 uint hrm_index() const { return _hrm_index; } 385 386 // The number of bytes marked live in the region in the last marking phase. 387 size_t marked_bytes() { return _prev_marked_bytes; } 388 size_t live_bytes() { 389 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 390 } 391 392 // The number of bytes counted in the next marking. 393 size_t next_marked_bytes() { return _next_marked_bytes; } 394 // The number of bytes live wrt the next marking. 395 size_t next_live_bytes() { 396 return 397 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 398 } 399 400 // A lower bound on the amount of garbage bytes in the region. 401 size_t garbage_bytes() { 402 size_t used_at_mark_start_bytes = 403 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 404 return used_at_mark_start_bytes - marked_bytes(); 405 } 406 407 // Return the amount of bytes we'll reclaim if we collect this 408 // region. This includes not only the known garbage bytes in the 409 // region but also any unallocated space in it, i.e., [top, end), 410 // since it will also be reclaimed if we collect the region. 411 size_t reclaimable_bytes() { 412 size_t known_live_bytes = live_bytes(); 413 assert(known_live_bytes <= capacity(), "sanity"); 414 return capacity() - known_live_bytes; 415 } 416 417 // An upper bound on the number of live bytes in the region. 418 size_t max_live_bytes() { return used() - garbage_bytes(); } 419 420 void add_to_marked_bytes(size_t incr_bytes) { 421 _next_marked_bytes = _next_marked_bytes + incr_bytes; 422 } 423 424 void zero_marked_bytes() { 425 _prev_marked_bytes = _next_marked_bytes = 0; 426 } 427 428 const char* get_type_str() const { return _type.get_str(); } 429 const char* get_short_type_str() const { return _type.get_short_str(); } 430 431 bool is_free() const { return _type.is_free(); } 432 433 bool is_young() const { return _type.is_young(); } 434 bool is_eden() const { return _type.is_eden(); } 435 bool is_survivor() const { return _type.is_survivor(); } 436 437 bool is_humongous() const { return _type.is_humongous(); } 438 bool is_starts_humongous() const { return _type.is_starts_humongous(); } 439 bool is_continues_humongous() const { return _type.is_continues_humongous(); } 440 441 bool is_old() const { return _type.is_old(); } 442 443 // A pinned region contains objects which are not moved by garbage collections. 444 // Humongous regions and archive regions are pinned. 445 bool is_pinned() const { return _type.is_pinned(); } 446 447 // An archive region is a pinned region, also tagged as old, which 448 // should not be marked during mark/sweep. This allows the address 449 // space to be shared by JVM instances. 450 bool is_archive() const { return _type.is_archive(); } 451 452 // For a humongous region, region in which it starts. 453 HeapRegion* humongous_start_region() const { 454 return _humongous_start_region; 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. 460 // 461 // obj_top : points to the top of the humongous object. 462 // fill_size : size of the filler object at the end of the region series. 463 void set_starts_humongous(HeapWord* obj_top, size_t fill_size); 464 465 // Makes the current region be a "continues humongous' 466 // region. first_hr is the "start humongous" region of the series 467 // which this region will be part of. 468 void set_continues_humongous(HeapRegion* first_hr); 469 470 // Unsets the humongous-related fields on the region. 471 void clear_humongous(); 472 473 // If the region has a remembered set, return a pointer to it. 474 HeapRegionRemSet* rem_set() const { 475 return _rem_set; 476 } 477 478 inline bool in_collection_set() const; 479 480 inline HeapRegion* next_in_collection_set() const; 481 inline void set_next_in_collection_set(HeapRegion* r); 482 483 void set_allocation_context(AllocationContext_t context) { 484 _allocation_context = context; 485 } 486 487 AllocationContext_t allocation_context() const { 488 return _allocation_context; 489 } 490 491 // Methods used by the HeapRegionSetBase class and subclasses. 492 493 // Getter and setter for the next and prev fields used to link regions into 494 // linked lists. 495 HeapRegion* next() { return _next; } 496 HeapRegion* prev() { return _prev; } 497 498 void set_next(HeapRegion* next) { _next = next; } 499 void set_prev(HeapRegion* prev) { _prev = prev; } 500 501 // Every region added to a set is tagged with a reference to that 502 // set. This is used for doing consistency checking to make sure that 503 // the contents of a set are as they should be and it's only 504 // available in non-product builds. 505 #ifdef ASSERT 506 void set_containing_set(HeapRegionSetBase* containing_set) { 507 assert((containing_set == NULL && _containing_set != NULL) || 508 (containing_set != NULL && _containing_set == NULL), 509 "containing_set: " PTR_FORMAT " " 510 "_containing_set: " PTR_FORMAT, 511 p2i(containing_set), p2i(_containing_set)); 512 513 _containing_set = containing_set; 514 } 515 516 HeapRegionSetBase* containing_set() { return _containing_set; } 517 #else // ASSERT 518 void set_containing_set(HeapRegionSetBase* containing_set) { } 519 520 // containing_set() is only used in asserts so there's no reason 521 // to provide a dummy version of it. 522 #endif // ASSERT 523 524 HeapRegion* get_next_young_region() { return _next_young_region; } 525 void set_next_young_region(HeapRegion* hr) { 526 _next_young_region = hr; 527 } 528 529 HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; } 530 HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; } 531 void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; } 532 bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; } 533 534 // Reset HR stuff to default values. 535 void hr_clear(bool par, bool clear_space, bool locked = false); 536 void par_clear(); 537 538 // Get the start of the unmarked area in this region. 539 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 540 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 541 542 // Note the start or end of marking. This tells the heap region 543 // that the collector is about to start or has finished (concurrently) 544 // marking the heap. 545 546 // Notify the region that concurrent marking is starting. Initialize 547 // all fields related to the next marking info. 548 inline void note_start_of_marking(); 549 550 // Notify the region that concurrent marking has finished. Copy the 551 // (now finalized) next marking info fields into the prev marking 552 // info fields. 553 inline void note_end_of_marking(); 554 555 // Notify the region that it will be used as to-space during a GC 556 // and we are about to start copying objects into it. 557 inline void note_start_of_copying(bool during_initial_mark); 558 559 // Notify the region that it ceases being to-space during a GC and 560 // we will not copy objects into it any more. 561 inline void note_end_of_copying(bool during_initial_mark); 562 563 // Notify the region that we are about to start processing 564 // self-forwarded objects during evac failure handling. 565 void note_self_forwarding_removal_start(bool during_initial_mark, 566 bool during_conc_mark); 567 568 // Notify the region that we have finished processing self-forwarded 569 // objects during evac failure handling. 570 void note_self_forwarding_removal_end(bool during_initial_mark, 571 bool during_conc_mark, 572 size_t marked_bytes); 573 574 // Returns "false" iff no object in the region was allocated when the 575 // last mark phase ended. 576 bool is_marked() { return _prev_top_at_mark_start != bottom(); } 577 578 void reset_during_compaction() { 579 assert(is_humongous(), 580 "should only be called for humongous regions"); 581 582 zero_marked_bytes(); 583 init_top_at_mark_start(); 584 } 585 586 void calc_gc_efficiency(void); 587 double gc_efficiency() { return _gc_efficiency;} 588 589 int young_index_in_cset() const { return _young_index_in_cset; } 590 void set_young_index_in_cset(int index) { 591 assert( (index == -1) || is_young(), "pre-condition" ); 592 _young_index_in_cset = index; 593 } 594 595 int age_in_surv_rate_group() { 596 assert( _surv_rate_group != NULL, "pre-condition" ); 597 assert( _age_index > -1, "pre-condition" ); 598 return _surv_rate_group->age_in_group(_age_index); 599 } 600 601 void record_surv_words_in_group(size_t words_survived) { 602 assert( _surv_rate_group != NULL, "pre-condition" ); 603 assert( _age_index > -1, "pre-condition" ); 604 int age_in_group = age_in_surv_rate_group(); 605 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 606 } 607 608 int age_in_surv_rate_group_cond() { 609 if (_surv_rate_group != NULL) 610 return age_in_surv_rate_group(); 611 else 612 return -1; 613 } 614 615 SurvRateGroup* surv_rate_group() { 616 return _surv_rate_group; 617 } 618 619 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 620 assert( surv_rate_group != NULL, "pre-condition" ); 621 assert( _surv_rate_group == NULL, "pre-condition" ); 622 assert( is_young(), "pre-condition" ); 623 624 _surv_rate_group = surv_rate_group; 625 _age_index = surv_rate_group->next_age_index(); 626 } 627 628 void uninstall_surv_rate_group() { 629 if (_surv_rate_group != NULL) { 630 assert( _age_index > -1, "pre-condition" ); 631 assert( is_young(), "pre-condition" ); 632 633 _surv_rate_group = NULL; 634 _age_index = -1; 635 } else { 636 assert( _age_index == -1, "pre-condition" ); 637 } 638 } 639 640 void set_free() { _type.set_free(); } 641 642 void set_eden() { _type.set_eden(); } 643 void set_eden_pre_gc() { _type.set_eden_pre_gc(); } 644 void set_survivor() { _type.set_survivor(); } 645 646 void set_old() { _type.set_old(); } 647 648 void set_archive() { _type.set_archive(); } 649 650 // Determine if an object has been allocated since the last 651 // mark performed by the collector. This returns true iff the object 652 // is within the unmarked area of the region. 653 bool obj_allocated_since_prev_marking(oop obj) const { 654 return (HeapWord *) obj >= prev_top_at_mark_start(); 655 } 656 bool obj_allocated_since_next_marking(oop obj) const { 657 return (HeapWord *) obj >= next_top_at_mark_start(); 658 } 659 660 // Returns the "evacuation_failed" property of the region. 661 bool evacuation_failed() { return _evacuation_failed; } 662 663 // Sets the "evacuation_failed" property of the region. 664 void set_evacuation_failed(bool b) { 665 _evacuation_failed = b; 666 667 if (b) { 668 _next_marked_bytes = 0; 669 } 670 } 671 672 // Requires that "mr" be entirely within the region. 673 // Apply "cl->do_object" to all objects that intersect with "mr". 674 // If the iteration encounters an unparseable portion of the region, 675 // or if "cl->abort()" is true after a closure application, 676 // terminate the iteration and return the address of the start of the 677 // subregion that isn't done. (The two can be distinguished by querying 678 // "cl->abort()".) Return of "NULL" indicates that the iteration 679 // completed. 680 HeapWord* 681 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl); 682 683 // filter_young: if true and the region is a young region then we 684 // skip the iteration. 685 // card_ptr: if not NULL, and we decide that the card is not young 686 // and we iterate over it, we'll clean the card before we start the 687 // iteration. 688 HeapWord* 689 oops_on_card_seq_iterate_careful(MemRegion mr, 690 FilterOutOfRegionClosure* cl, 691 bool filter_young, 692 jbyte* card_ptr); 693 694 size_t recorded_rs_length() const { return _recorded_rs_length; } 695 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 696 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; } 697 698 void set_recorded_rs_length(size_t rs_length) { 699 _recorded_rs_length = rs_length; 700 } 701 702 void set_predicted_elapsed_time_ms(double ms) { 703 _predicted_elapsed_time_ms = ms; 704 } 705 706 void set_predicted_bytes_to_copy(size_t bytes) { 707 _predicted_bytes_to_copy = bytes; 708 } 709 710 virtual CompactibleSpace* next_compaction_space() const; 711 712 virtual void reset_after_compaction(); 713 714 // Routines for managing a list of code roots (attached to the 715 // this region's RSet) that point into this heap region. 716 void add_strong_code_root(nmethod* nm); 717 void add_strong_code_root_locked(nmethod* nm); 718 void remove_strong_code_root(nmethod* nm); 719 720 // Applies blk->do_code_blob() to each of the entries in 721 // the strong code roots list for this region 722 void strong_code_roots_do(CodeBlobClosure* blk) const; 723 724 // Verify that the entries on the strong code root list for this 725 // region are live and include at least one pointer into this region. 726 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 727 728 void print() const; 729 void print_on(outputStream* st) const; 730 731 // vo == UsePrevMarking -> use "prev" marking information, 732 // vo == UseNextMarking -> use "next" marking information 733 // vo == UseMarkWord -> use the mark word in the object header 734 // 735 // NOTE: Only the "prev" marking information is guaranteed to be 736 // consistent most of the time, so most calls to this should use 737 // vo == UsePrevMarking. 738 // Currently, there is only one case where this is called with 739 // vo == UseNextMarking, which is to verify the "next" marking 740 // information at the end of remark. 741 // Currently there is only one place where this is called with 742 // vo == UseMarkWord, which is to verify the marking during a 743 // full GC. 744 void verify(VerifyOption vo, bool *failures) const; 745 746 // Override; it uses the "prev" marking information 747 virtual void verify() const; 748 }; 749 750 // HeapRegionClosure is used for iterating over regions. 751 // Terminates the iteration when the "doHeapRegion" method returns "true". 752 class HeapRegionClosure : public StackObj { 753 friend class HeapRegionManager; 754 friend class G1CollectedHeap; 755 756 bool _complete; 757 void incomplete() { _complete = false; } 758 759 public: 760 HeapRegionClosure(): _complete(true) {} 761 762 // Typically called on each region until it returns true. 763 virtual bool doHeapRegion(HeapRegion* r) = 0; 764 765 // True after iteration if the closure was applied to all heap regions 766 // and returned "false" in all cases. 767 bool complete() { return _complete; } 768 }; 769 770 #endif // SHARE_VM_GC_G1_HEAPREGION_HPP