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/g1HeapRegionTraceType.hpp" 31 #include "gc/g1/heapRegionTracer.hpp" 32 #include "gc/g1/heapRegionType.hpp" 33 #include "gc/g1/survRateGroup.hpp" 34 #include "gc/shared/ageTable.hpp" 35 #include "gc/shared/spaceDecorator.hpp" 36 #include "utilities/macros.hpp" 37 38 // A HeapRegion is the smallest piece of a G1CollectedHeap that 39 // can be collected independently. 40 41 // NOTE: Although a HeapRegion is a Space, its 42 // Space::initDirtyCardClosure method must not be called. 43 // The problem is that the existence of this method breaks 44 // the independence of barrier sets from remembered sets. 45 // The solution is to remove this method from the definition 46 // of a Space. 47 48 // Each heap region is self contained. top() and end() can never 49 // be set beyond the end of the region. For humongous objects, 50 // the first region is a StartsHumongous region. If the humongous 51 // object is larger than a heap region, the following regions will 52 // be of type ContinuesHumongous. In this case the top() of the 53 // StartHumongous region and all ContinuesHumongous regions except 54 // the last will point to their own end. For the last ContinuesHumongous 55 // region, top() will equal the object's top. 56 57 class G1CollectedHeap; 58 class HeapRegionRemSet; 59 class HeapRegionRemSetIterator; 60 class HeapRegion; 61 class HeapRegionSetBase; 62 class nmethod; 63 64 #define HR_FORMAT "%u:(%s)[" PTR_FORMAT "," PTR_FORMAT "," PTR_FORMAT "]" 65 #define HR_FORMAT_PARAMS(_hr_) \ 66 (_hr_)->hrm_index(), \ 67 (_hr_)->get_short_type_str(), \ 68 p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end()) 69 70 // sentinel value for hrm_index 71 #define G1_NO_HRM_INDEX ((uint) -1) 72 73 // A dirty card to oop closure for heap regions. It 74 // knows how to get the G1 heap and how to use the bitmap 75 // in the concurrent marker used by G1 to filter remembered 76 // sets. 77 78 class HeapRegionDCTOC : public DirtyCardToOopClosure { 79 private: 80 HeapRegion* _hr; 81 G1ParPushHeapRSClosure* _rs_scan; 82 G1CollectedHeap* _g1; 83 84 // Walk the given memory region from bottom to (actual) top 85 // looking for objects and applying the oop closure (_cl) to 86 // them. The base implementation of this treats the area as 87 // blocks, where a block may or may not be an object. Sub- 88 // classes should override this to provide more accurate 89 // or possibly more efficient walking. 90 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top); 91 92 public: 93 HeapRegionDCTOC(G1CollectedHeap* g1, 94 HeapRegion* hr, 95 G1ParPushHeapRSClosure* cl, 96 CardTableModRefBS::PrecisionStyle precision); 97 }; 98 99 // The complicating factor is that BlockOffsetTable diverged 100 // significantly, and we need functionality that is only in the G1 version. 101 // So I copied that code, which led to an alternate G1 version of 102 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could 103 // be reconciled, then G1OffsetTableContigSpace could go away. 104 105 // The idea behind time stamps is the following. We want to keep track of 106 // the highest address where it's safe to scan objects for each region. 107 // This is only relevant for current GC alloc regions so we keep a time stamp 108 // per region to determine if the region has been allocated during the current 109 // GC or not. If the time stamp is current we report a scan_top value which 110 // was saved at the end of the previous GC for retained alloc regions and which is 111 // equal to the bottom for all other regions. 112 // There is a race between card scanners and allocating gc workers where we must ensure 113 // that card scanners do not read the memory allocated by the gc workers. 114 // In order to enforce that, we must not return a value of _top which is more recent than the 115 // time stamp. This is due to the fact that a region may become a gc alloc region at 116 // some point after we've read the timestamp value as being < the current time stamp. 117 // The time stamps are re-initialized to zero at cleanup and at Full GCs. 118 // The current scheme that uses sequential unsigned ints will fail only if we have 4b 119 // evacuation pauses between two cleanups, which is _highly_ unlikely. 120 class G1ContiguousSpace: public CompactibleSpace { 121 friend class VMStructs; 122 HeapWord* volatile _top; 123 HeapWord* volatile _scan_top; 124 protected: 125 G1BlockOffsetTablePart _bot_part; 126 Mutex _par_alloc_lock; 127 volatile unsigned _gc_time_stamp; 128 // When we need to retire an allocation region, while other threads 129 // are also concurrently trying to allocate into it, we typically 130 // allocate a dummy object at the end of the region to ensure that 131 // no more allocations can take place in it. However, sometimes we 132 // want to know where the end of the last "real" object we allocated 133 // into the region was and this is what this keeps track. 134 HeapWord* _pre_dummy_top; 135 136 public: 137 G1ContiguousSpace(G1BlockOffsetTable* bot); 138 139 void set_top(HeapWord* value) { _top = value; } 140 HeapWord* top() const { return _top; } 141 142 protected: 143 // Reset the G1ContiguousSpace. 144 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); 145 146 HeapWord* volatile* top_addr() { return &_top; } 147 // Try to allocate at least min_word_size and up to desired_size from this Space. 148 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 149 // space allocated. 150 // This version assumes that all allocation requests to this Space are properly 151 // synchronized. 152 inline HeapWord* allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 153 // Try to allocate at least min_word_size and up to desired_size from this Space. 154 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 155 // space allocated. 156 // This version synchronizes with other calls to par_allocate_impl(). 157 inline HeapWord* par_allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 158 159 public: 160 void reset_after_compaction() { set_top(compaction_top()); } 161 162 size_t used() const { return byte_size(bottom(), top()); } 163 size_t free() const { return byte_size(top(), end()); } 164 bool is_free_block(const HeapWord* p) const { return p >= top(); } 165 166 MemRegion used_region() const { return MemRegion(bottom(), top()); } 167 168 void object_iterate(ObjectClosure* blk); 169 void safe_object_iterate(ObjectClosure* blk); 170 171 void mangle_unused_area() PRODUCT_RETURN; 172 void mangle_unused_area_complete() PRODUCT_RETURN; 173 174 HeapWord* scan_top() const; 175 void record_timestamp(); 176 void reset_gc_time_stamp() { _gc_time_stamp = 0; } 177 unsigned get_gc_time_stamp() { return _gc_time_stamp; } 178 void record_retained_region(); 179 180 // See the comment above in the declaration of _pre_dummy_top for an 181 // explanation of what it is. 182 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 183 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 184 _pre_dummy_top = pre_dummy_top; 185 } 186 HeapWord* pre_dummy_top() { 187 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; 188 } 189 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 190 191 virtual void clear(bool mangle_space); 192 193 HeapWord* block_start(const void* p); 194 HeapWord* block_start_const(const void* p) const; 195 196 // Allocation (return NULL if full). Assumes the caller has established 197 // mutually exclusive access to the space. 198 HeapWord* allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 199 // Allocation (return NULL if full). Enforces mutual exclusion internally. 200 HeapWord* par_allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 201 202 virtual HeapWord* allocate(size_t word_size); 203 virtual HeapWord* par_allocate(size_t word_size); 204 205 HeapWord* saved_mark_word() const { ShouldNotReachHere(); return NULL; } 206 207 // MarkSweep support phase3 208 virtual HeapWord* initialize_threshold(); 209 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 210 211 virtual void print() const; 212 213 void reset_bot() { 214 _bot_part.reset_bot(); 215 } 216 217 void print_bot_on(outputStream* out) { 218 _bot_part.print_on(out); 219 } 220 }; 221 222 class HeapRegion: public G1ContiguousSpace { 223 friend class VMStructs; 224 // Allow scan_and_forward to call (private) overrides for auxiliary functions on this class 225 template <typename SpaceType> 226 friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp); 227 private: 228 229 // The remembered set for this region. 230 // (Might want to make this "inline" later, to avoid some alloc failure 231 // issues.) 232 HeapRegionRemSet* _rem_set; 233 234 // Auxiliary functions for scan_and_forward support. 235 // See comments for CompactibleSpace for more information. 236 inline HeapWord* scan_limit() const { 237 return top(); 238 } 239 240 inline bool scanned_block_is_obj(const HeapWord* addr) const { 241 return true; // Always true, since scan_limit is top 242 } 243 244 inline size_t scanned_block_size(const HeapWord* addr) const { 245 return HeapRegion::block_size(addr); // Avoid virtual call 246 } 247 248 void report_region_type_change(G1HeapRegionTraceType::Type to); 249 250 protected: 251 // The index of this region in the heap region sequence. 252 uint _hrm_index; 253 254 AllocationContext_t _allocation_context; 255 256 HeapRegionType _type; 257 258 // For a humongous region, region in which it starts. 259 HeapRegion* _humongous_start_region; 260 261 // True iff an attempt to evacuate an object in the region failed. 262 bool _evacuation_failed; 263 264 // A heap region may be a member one of a number of special subsets, each 265 // represented as linked lists through the field below. Currently, there 266 // is only one set: 267 // The collection set. 268 HeapRegion* _next_in_special_set; 269 270 // next region in the young "generation" region set 271 HeapRegion* _next_young_region; 272 273 // Next region whose cards need cleaning 274 HeapRegion* _next_dirty_cards_region; 275 276 // Fields used by the HeapRegionSetBase class and subclasses. 277 HeapRegion* _next; 278 HeapRegion* _prev; 279 #ifdef ASSERT 280 HeapRegionSetBase* _containing_set; 281 #endif // ASSERT 282 283 // We use concurrent marking to determine the amount of live data 284 // in each heap region. 285 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 286 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 287 288 // The calculated GC efficiency of the region. 289 double _gc_efficiency; 290 291 int _young_index_in_cset; 292 SurvRateGroup* _surv_rate_group; 293 int _age_index; 294 295 // The start of the unmarked area. The unmarked area extends from this 296 // word until the top and/or end of the region, and is the part 297 // of the region for which no marking was done, i.e. objects may 298 // have been allocated in this part since the last mark phase. 299 // "prev" is the top at the start of the last completed marking. 300 // "next" is the top at the start of the in-progress marking (if any.) 301 HeapWord* _prev_top_at_mark_start; 302 HeapWord* _next_top_at_mark_start; 303 // If a collection pause is in progress, this is the top at the start 304 // of that pause. 305 306 void init_top_at_mark_start() { 307 assert(_prev_marked_bytes == 0 && 308 _next_marked_bytes == 0, 309 "Must be called after zero_marked_bytes."); 310 HeapWord* bot = bottom(); 311 _prev_top_at_mark_start = bot; 312 _next_top_at_mark_start = bot; 313 } 314 315 // Cached attributes used in the collection set policy information 316 317 // The RSet length that was added to the total value 318 // for the collection set. 319 size_t _recorded_rs_length; 320 321 // The predicted elapsed time that was added to total value 322 // for the collection set. 323 double _predicted_elapsed_time_ms; 324 325 // The predicted number of bytes to copy that was added to 326 // the total value for the collection set. 327 size_t _predicted_bytes_to_copy; 328 329 public: 330 HeapRegion(uint hrm_index, 331 G1BlockOffsetTable* bot, 332 MemRegion mr); 333 334 // Initializing the HeapRegion not only resets the data structure, but also 335 // resets the BOT for that heap region. 336 // The default values for clear_space means that we will do the clearing if 337 // there's clearing to be done ourselves. We also always mangle the space. 338 virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 339 340 static int LogOfHRGrainBytes; 341 static int LogOfHRGrainWords; 342 343 static size_t GrainBytes; 344 static size_t GrainWords; 345 static size_t CardsPerRegion; 346 347 static size_t align_up_to_region_byte_size(size_t sz) { 348 return (sz + (size_t) GrainBytes - 1) & 349 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 350 } 351 352 353 // Returns whether a field is in the same region as the obj it points to. 354 template <typename T> 355 static bool is_in_same_region(T* p, oop obj) { 356 assert(p != NULL, "p can't be NULL"); 357 assert(obj != NULL, "obj can't be NULL"); 358 return (((uintptr_t) p ^ cast_from_oop<uintptr_t>(obj)) >> LogOfHRGrainBytes) == 0; 359 } 360 361 static size_t max_region_size(); 362 static size_t min_region_size_in_words(); 363 364 // It sets up the heap region size (GrainBytes / GrainWords), as 365 // well as other related fields that are based on the heap region 366 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 367 // CardsPerRegion). All those fields are considered constant 368 // throughout the JVM's execution, therefore they should only be set 369 // up once during initialization time. 370 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 371 372 // All allocated blocks are occupied by objects in a HeapRegion 373 bool block_is_obj(const HeapWord* p) const; 374 375 // Returns the object size for all valid block starts 376 // and the amount of unallocated words if called on top() 377 size_t block_size(const HeapWord* p) const; 378 379 // Override for scan_and_forward support. 380 void prepare_for_compaction(CompactPoint* cp); 381 382 inline HeapWord* par_allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* word_size); 383 inline HeapWord* allocate_no_bot_updates(size_t word_size); 384 inline HeapWord* allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* actual_size); 385 386 // If this region is a member of a HeapRegionManager, the index in that 387 // sequence, otherwise -1. 388 uint hrm_index() const { return _hrm_index; } 389 390 // The number of bytes marked live in the region in the last marking phase. 391 size_t marked_bytes() { return _prev_marked_bytes; } 392 size_t live_bytes() { 393 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 394 } 395 396 // The number of bytes counted in the next marking. 397 size_t next_marked_bytes() { return _next_marked_bytes; } 398 // The number of bytes live wrt the next marking. 399 size_t next_live_bytes() { 400 return 401 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 402 } 403 404 // A lower bound on the amount of garbage bytes in the region. 405 size_t garbage_bytes() { 406 size_t used_at_mark_start_bytes = 407 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 408 return used_at_mark_start_bytes - marked_bytes(); 409 } 410 411 // Return the amount of bytes we'll reclaim if we collect this 412 // region. This includes not only the known garbage bytes in the 413 // region but also any unallocated space in it, i.e., [top, end), 414 // since it will also be reclaimed if we collect the region. 415 size_t reclaimable_bytes() { 416 size_t known_live_bytes = live_bytes(); 417 assert(known_live_bytes <= capacity(), "sanity"); 418 return capacity() - known_live_bytes; 419 } 420 421 // An upper bound on the number of live bytes in the region. 422 size_t max_live_bytes() { return used() - garbage_bytes(); } 423 424 void add_to_marked_bytes(size_t incr_bytes) { 425 _next_marked_bytes = _next_marked_bytes + incr_bytes; 426 } 427 428 void zero_marked_bytes() { 429 _prev_marked_bytes = _next_marked_bytes = 0; 430 } 431 432 const char* get_type_str() const { return _type.get_str(); } 433 const char* get_short_type_str() const { return _type.get_short_str(); } 434 G1HeapRegionTraceType::Type get_trace_type() { return _type.get_trace_type(); } 435 436 bool is_free() const { return _type.is_free(); } 437 438 bool is_young() const { return _type.is_young(); } 439 bool is_eden() const { return _type.is_eden(); } 440 bool is_survivor() const { return _type.is_survivor(); } 441 442 bool is_humongous() const { return _type.is_humongous(); } 443 bool is_starts_humongous() const { return _type.is_starts_humongous(); } 444 bool is_continues_humongous() const { return _type.is_continues_humongous(); } 445 446 bool is_old() const { return _type.is_old(); } 447 448 // A pinned region contains objects which are not moved by garbage collections. 449 // Humongous regions and archive regions are pinned. 450 bool is_pinned() const { return _type.is_pinned(); } 451 452 // An archive region is a pinned region, also tagged as old, which 453 // should not be marked during mark/sweep. This allows the address 454 // space to be shared by JVM instances. 455 bool is_archive() const { return _type.is_archive(); } 456 457 // For a humongous region, region in which it starts. 458 HeapRegion* humongous_start_region() const { 459 return _humongous_start_region; 460 } 461 462 // Makes the current region be a "starts humongous" region, i.e., 463 // the first region in a series of one or more contiguous regions 464 // that will contain a single "humongous" object. 465 // 466 // obj_top : points to the top of the humongous object. 467 // fill_size : size of the filler object at the end of the region series. 468 void set_starts_humongous(HeapWord* obj_top, size_t fill_size); 469 470 // Makes the current region be a "continues humongous' 471 // region. first_hr is the "start humongous" region of the series 472 // which this region will be part of. 473 void set_continues_humongous(HeapRegion* first_hr); 474 475 // Unsets the humongous-related fields on the region. 476 void clear_humongous(); 477 478 // If the region has a remembered set, return a pointer to it. 479 HeapRegionRemSet* rem_set() const { 480 return _rem_set; 481 } 482 483 inline bool in_collection_set() const; 484 485 inline HeapRegion* next_in_collection_set() const; 486 inline void set_next_in_collection_set(HeapRegion* r); 487 488 void set_allocation_context(AllocationContext_t context) { 489 _allocation_context = context; 490 } 491 492 AllocationContext_t allocation_context() const { 493 return _allocation_context; 494 } 495 496 // Methods used by the HeapRegionSetBase class and subclasses. 497 498 // Getter and setter for the next and prev fields used to link regions into 499 // linked lists. 500 HeapRegion* next() { return _next; } 501 HeapRegion* prev() { return _prev; } 502 503 void set_next(HeapRegion* next) { _next = next; } 504 void set_prev(HeapRegion* prev) { _prev = prev; } 505 506 // Every region added to a set is tagged with a reference to that 507 // set. This is used for doing consistency checking to make sure that 508 // the contents of a set are as they should be and it's only 509 // available in non-product builds. 510 #ifdef ASSERT 511 void set_containing_set(HeapRegionSetBase* containing_set) { 512 assert((containing_set == NULL && _containing_set != NULL) || 513 (containing_set != NULL && _containing_set == NULL), 514 "containing_set: " PTR_FORMAT " " 515 "_containing_set: " PTR_FORMAT, 516 p2i(containing_set), p2i(_containing_set)); 517 518 _containing_set = containing_set; 519 } 520 521 HeapRegionSetBase* containing_set() { return _containing_set; } 522 #else // ASSERT 523 void set_containing_set(HeapRegionSetBase* containing_set) { } 524 525 // containing_set() is only used in asserts so there's no reason 526 // to provide a dummy version of it. 527 #endif // ASSERT 528 529 HeapRegion* get_next_young_region() { return _next_young_region; } 530 void set_next_young_region(HeapRegion* hr) { 531 _next_young_region = hr; 532 } 533 534 HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; } 535 HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; } 536 void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; } 537 bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; } 538 539 // Reset HR stuff to default values. 540 void hr_clear(bool par, bool clear_space, bool locked = false); 541 void par_clear(); 542 543 // Get the start of the unmarked area in this region. 544 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 545 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 546 547 // Note the start or end of marking. This tells the heap region 548 // that the collector is about to start or has finished (concurrently) 549 // marking the heap. 550 551 // Notify the region that concurrent marking is starting. Initialize 552 // all fields related to the next marking info. 553 inline void note_start_of_marking(); 554 555 // Notify the region that concurrent marking has finished. Copy the 556 // (now finalized) next marking info fields into the prev marking 557 // info fields. 558 inline void note_end_of_marking(); 559 560 // Notify the region that it will be used as to-space during a GC 561 // and we are about to start copying objects into it. 562 inline void note_start_of_copying(bool during_initial_mark); 563 564 // Notify the region that it ceases being to-space during a GC and 565 // we will not copy objects into it any more. 566 inline void note_end_of_copying(bool during_initial_mark); 567 568 // Notify the region that we are about to start processing 569 // self-forwarded objects during evac failure handling. 570 void note_self_forwarding_removal_start(bool during_initial_mark, 571 bool during_conc_mark); 572 573 // Notify the region that we have finished processing self-forwarded 574 // objects during evac failure handling. 575 void note_self_forwarding_removal_end(bool during_initial_mark, 576 bool during_conc_mark, 577 size_t marked_bytes); 578 579 // Returns "false" iff no object in the region was allocated when the 580 // last mark phase ended. 581 bool is_marked() { return _prev_top_at_mark_start != bottom(); } 582 583 void reset_during_compaction() { 584 assert(is_humongous(), 585 "should only be called for humongous regions"); 586 587 zero_marked_bytes(); 588 init_top_at_mark_start(); 589 } 590 591 void calc_gc_efficiency(void); 592 double gc_efficiency() { return _gc_efficiency;} 593 594 int young_index_in_cset() const { return _young_index_in_cset; } 595 void set_young_index_in_cset(int index) { 596 assert( (index == -1) || is_young(), "pre-condition" ); 597 _young_index_in_cset = index; 598 } 599 600 int age_in_surv_rate_group() { 601 assert( _surv_rate_group != NULL, "pre-condition" ); 602 assert( _age_index > -1, "pre-condition" ); 603 return _surv_rate_group->age_in_group(_age_index); 604 } 605 606 void record_surv_words_in_group(size_t words_survived) { 607 assert( _surv_rate_group != NULL, "pre-condition" ); 608 assert( _age_index > -1, "pre-condition" ); 609 int age_in_group = age_in_surv_rate_group(); 610 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 611 } 612 613 int age_in_surv_rate_group_cond() { 614 if (_surv_rate_group != NULL) 615 return age_in_surv_rate_group(); 616 else 617 return -1; 618 } 619 620 SurvRateGroup* surv_rate_group() { 621 return _surv_rate_group; 622 } 623 624 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 625 assert( surv_rate_group != NULL, "pre-condition" ); 626 assert( _surv_rate_group == NULL, "pre-condition" ); 627 assert( is_young(), "pre-condition" ); 628 629 _surv_rate_group = surv_rate_group; 630 _age_index = surv_rate_group->next_age_index(); 631 } 632 633 void uninstall_surv_rate_group() { 634 if (_surv_rate_group != NULL) { 635 assert( _age_index > -1, "pre-condition" ); 636 assert( is_young(), "pre-condition" ); 637 638 _surv_rate_group = NULL; 639 _age_index = -1; 640 } else { 641 assert( _age_index == -1, "pre-condition" ); 642 } 643 } 644 645 void set_free(); 646 647 void set_eden(); 648 void set_eden_pre_gc(); 649 void set_survivor(); 650 651 void set_old(); 652 653 void set_archive(); 654 655 // Determine if an object has been allocated since the last 656 // mark performed by the collector. This returns true iff the object 657 // is within the unmarked area of the region. 658 bool obj_allocated_since_prev_marking(oop obj) const { 659 return (HeapWord *) obj >= prev_top_at_mark_start(); 660 } 661 bool obj_allocated_since_next_marking(oop obj) const { 662 return (HeapWord *) obj >= next_top_at_mark_start(); 663 } 664 665 // Returns the "evacuation_failed" property of the region. 666 bool evacuation_failed() { return _evacuation_failed; } 667 668 // Sets the "evacuation_failed" property of the region. 669 void set_evacuation_failed(bool b) { 670 _evacuation_failed = b; 671 672 if (b) { 673 _next_marked_bytes = 0; 674 } 675 } 676 677 // Requires that "mr" be entirely within the region. 678 // Apply "cl->do_object" to all objects that intersect with "mr". 679 // If the iteration encounters an unparseable portion of the region, 680 // or if "cl->abort()" is true after a closure application, 681 // terminate the iteration and return the address of the start of the 682 // subregion that isn't done. (The two can be distinguished by querying 683 // "cl->abort()".) Return of "NULL" indicates that the iteration 684 // completed. 685 HeapWord* 686 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl); 687 688 // filter_young: if true and the region is a young region then we 689 // skip the iteration. 690 // card_ptr: if not NULL, and we decide that the card is not young 691 // and we iterate over it, we'll clean the card before we start the 692 // iteration. 693 HeapWord* 694 oops_on_card_seq_iterate_careful(MemRegion mr, 695 FilterOutOfRegionClosure* cl, 696 bool filter_young, 697 jbyte* card_ptr); 698 699 size_t recorded_rs_length() const { return _recorded_rs_length; } 700 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 701 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; } 702 703 void set_recorded_rs_length(size_t rs_length) { 704 _recorded_rs_length = rs_length; 705 } 706 707 void set_predicted_elapsed_time_ms(double ms) { 708 _predicted_elapsed_time_ms = ms; 709 } 710 711 void set_predicted_bytes_to_copy(size_t bytes) { 712 _predicted_bytes_to_copy = bytes; 713 } 714 715 virtual CompactibleSpace* next_compaction_space() const; 716 717 virtual void reset_after_compaction(); 718 719 // Routines for managing a list of code roots (attached to the 720 // this region's RSet) that point into this heap region. 721 void add_strong_code_root(nmethod* nm); 722 void add_strong_code_root_locked(nmethod* nm); 723 void remove_strong_code_root(nmethod* nm); 724 725 // Applies blk->do_code_blob() to each of the entries in 726 // the strong code roots list for this region 727 void strong_code_roots_do(CodeBlobClosure* blk) const; 728 729 // Verify that the entries on the strong code root list for this 730 // region are live and include at least one pointer into this region. 731 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 732 733 void print() const; 734 void print_on(outputStream* st) const; 735 736 // vo == UsePrevMarking -> use "prev" marking information, 737 // vo == UseNextMarking -> use "next" marking information 738 // vo == UseMarkWord -> use the mark word in the object header 739 // 740 // NOTE: Only the "prev" marking information is guaranteed to be 741 // consistent most of the time, so most calls to this should use 742 // vo == UsePrevMarking. 743 // Currently, there is only one case where this is called with 744 // vo == UseNextMarking, which is to verify the "next" marking 745 // information at the end of remark. 746 // Currently there is only one place where this is called with 747 // vo == UseMarkWord, which is to verify the marking during a 748 // full GC. 749 void verify(VerifyOption vo, bool *failures) const; 750 751 // Override; it uses the "prev" marking information 752 virtual void verify() const; 753 754 void verify_rem_set(VerifyOption vo, bool *failures) const; 755 void verify_rem_set() const; 756 }; 757 758 // HeapRegionClosure is used for iterating over regions. 759 // Terminates the iteration when the "doHeapRegion" method returns "true". 760 class HeapRegionClosure : public StackObj { 761 friend class HeapRegionManager; 762 friend class G1CollectedHeap; 763 764 bool _complete; 765 void incomplete() { _complete = false; } 766 767 public: 768 HeapRegionClosure(): _complete(true) {} 769 770 // Typically called on each region until it returns true. 771 virtual bool doHeapRegion(HeapRegion* r) = 0; 772 773 // True after iteration if the closure was applied to all heap regions 774 // and returned "false" in all cases. 775 bool complete() { return _complete; } 776 }; 777 778 #endif // SHARE_VM_GC_G1_HEAPREGION_HPP