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/cardTable.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. The last ContinuesHumongous 55 // region may have top() equal the end of object if there isn't 56 // room for filler objects to pad out to the end of the region. 57 58 class G1CollectedHeap; 59 class G1CMBitMap; 60 class G1IsAliveAndApplyClosure; 61 class HeapRegionRemSet; 62 class HeapRegionRemSetIterator; 63 class HeapRegion; 64 class HeapRegionSetBase; 65 class nmethod; 66 67 #define HR_FORMAT "%u:(%s)[" PTR_FORMAT "," PTR_FORMAT "," PTR_FORMAT "]" 68 #define HR_FORMAT_PARAMS(_hr_) \ 69 (_hr_)->hrm_index(), \ 70 (_hr_)->get_short_type_str(), \ 71 p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end()) 72 73 // sentinel value for hrm_index 74 #define G1_NO_HRM_INDEX ((uint) -1) 75 76 // The complicating factor is that BlockOffsetTable diverged 77 // significantly, and we need functionality that is only in the G1 version. 78 // So I copied that code, which led to an alternate G1 version of 79 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could 80 // be reconciled, then G1OffsetTableContigSpace could go away. 81 82 // The idea behind time stamps is the following. We want to keep track of 83 // the highest address where it's safe to scan objects for each region. 84 // This is only relevant for current GC alloc regions so we keep a time stamp 85 // per region to determine if the region has been allocated during the current 86 // GC or not. If the time stamp is current we report a scan_top value which 87 // was saved at the end of the previous GC for retained alloc regions and which is 88 // equal to the bottom for all other regions. 89 // There is a race between card scanners and allocating gc workers where we must ensure 90 // that card scanners do not read the memory allocated by the gc workers. 91 // In order to enforce that, we must not return a value of _top which is more recent than the 92 // time stamp. This is due to the fact that a region may become a gc alloc region at 93 // some point after we've read the timestamp value as being < the current time stamp. 94 // The time stamps are re-initialized to zero at cleanup and at Full GCs. 95 // The current scheme that uses sequential unsigned ints will fail only if we have 4b 96 // evacuation pauses between two cleanups, which is _highly_ unlikely. 97 class G1ContiguousSpace: public CompactibleSpace { 98 friend class VMStructs; 99 HeapWord* volatile _top; 100 protected: 101 G1BlockOffsetTablePart _bot_part; 102 Mutex _par_alloc_lock; 103 // When we need to retire an allocation region, while other threads 104 // are also concurrently trying to allocate into it, we typically 105 // allocate a dummy object at the end of the region to ensure that 106 // no more allocations can take place in it. However, sometimes we 107 // want to know where the end of the last "real" object we allocated 108 // into the region was and this is what this keeps track. 109 HeapWord* _pre_dummy_top; 110 111 public: 112 G1ContiguousSpace(G1BlockOffsetTable* bot); 113 114 void set_top(HeapWord* value) { _top = value; } 115 HeapWord* top() const { return _top; } 116 117 protected: 118 // Reset the G1ContiguousSpace. 119 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); 120 121 HeapWord* volatile* top_addr() { return &_top; } 122 // Try to allocate at least min_word_size and up to desired_size from this Space. 123 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 124 // space allocated. 125 // This version assumes that all allocation requests to this Space are properly 126 // synchronized. 127 inline HeapWord* allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 128 // Try to allocate at least min_word_size and up to desired_size from this Space. 129 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 130 // space allocated. 131 // This version synchronizes with other calls to par_allocate_impl(). 132 inline HeapWord* par_allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 133 134 public: 135 void reset_after_compaction() { set_top(compaction_top()); } 136 137 size_t used() const { return byte_size(bottom(), top()); } 138 size_t free() const { return byte_size(top(), end()); } 139 bool is_free_block(const HeapWord* p) const { return p >= top(); } 140 141 MemRegion used_region() const { return MemRegion(bottom(), top()); } 142 143 void object_iterate(ObjectClosure* blk); 144 void safe_object_iterate(ObjectClosure* blk); 145 146 void mangle_unused_area() PRODUCT_RETURN; 147 void mangle_unused_area_complete() PRODUCT_RETURN; 148 149 // See the comment above in the declaration of _pre_dummy_top for an 150 // explanation of what it is. 151 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 152 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 153 _pre_dummy_top = pre_dummy_top; 154 } 155 HeapWord* pre_dummy_top() { 156 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; 157 } 158 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 159 160 virtual void clear(bool mangle_space); 161 162 HeapWord* block_start(const void* p); 163 HeapWord* block_start_const(const void* p) const; 164 165 // Allocation (return NULL if full). Assumes the caller has established 166 // mutually exclusive access to the space. 167 HeapWord* allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 168 // Allocation (return NULL if full). Enforces mutual exclusion internally. 169 HeapWord* par_allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 170 171 virtual HeapWord* allocate(size_t word_size); 172 virtual HeapWord* par_allocate(size_t word_size); 173 174 HeapWord* saved_mark_word() const { ShouldNotReachHere(); return NULL; } 175 176 // MarkSweep support phase3 177 virtual HeapWord* initialize_threshold(); 178 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 179 180 virtual void print() const; 181 182 void reset_bot() { 183 _bot_part.reset_bot(); 184 } 185 186 void print_bot_on(outputStream* out) { 187 _bot_part.print_on(out); 188 } 189 }; 190 191 class HeapRegion: public G1ContiguousSpace { 192 friend class VMStructs; 193 // Allow scan_and_forward to call (private) overrides for auxiliary functions on this class 194 template <typename SpaceType> 195 friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp); 196 private: 197 198 // The remembered set for this region. 199 // (Might want to make this "inline" later, to avoid some alloc failure 200 // issues.) 201 HeapRegionRemSet* _rem_set; 202 203 // Auxiliary functions for scan_and_forward support. 204 // See comments for CompactibleSpace for more information. 205 inline HeapWord* scan_limit() const { 206 return top(); 207 } 208 209 inline bool scanned_block_is_obj(const HeapWord* addr) const { 210 return true; // Always true, since scan_limit is top 211 } 212 213 inline size_t scanned_block_size(const HeapWord* addr) const { 214 return HeapRegion::block_size(addr); // Avoid virtual call 215 } 216 217 void report_region_type_change(G1HeapRegionTraceType::Type to); 218 219 // Returns whether the given object address refers to a dead object, and either the 220 // size of the object (if live) or the size of the block (if dead) in size. 221 // May 222 // - only called with obj < top() 223 // - not called on humongous objects or archive regions 224 inline bool is_obj_dead_with_size(const oop obj, const G1CMBitMap* const prev_bitmap, size_t* size) const; 225 226 protected: 227 // The index of this region in the heap region sequence. 228 uint _hrm_index; 229 230 HeapRegionType _type; 231 232 // For a humongous region, region in which it starts. 233 HeapRegion* _humongous_start_region; 234 235 // True iff an attempt to evacuate an object in the region failed. 236 bool _evacuation_failed; 237 238 // Fields used by the HeapRegionSetBase class and subclasses. 239 HeapRegion* _next; 240 HeapRegion* _prev; 241 #ifdef ASSERT 242 HeapRegionSetBase* _containing_set; 243 #endif // ASSERT 244 245 // We use concurrent marking to determine the amount of live data 246 // in each heap region. 247 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 248 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 249 250 // The calculated GC efficiency of the region. 251 double _gc_efficiency; 252 253 // The index in the optional regions array, if this region 254 // is considered optional during a mixed collections. 255 uint _index_in_opt_cset; 256 int _young_index_in_cset; 257 SurvRateGroup* _surv_rate_group; 258 int _age_index; 259 260 // The start of the unmarked area. The unmarked area extends from this 261 // word until the top and/or end of the region, and is the part 262 // of the region for which no marking was done, i.e. objects may 263 // have been allocated in this part since the last mark phase. 264 // "prev" is the top at the start of the last completed marking. 265 // "next" is the top at the start of the in-progress marking (if any.) 266 HeapWord* _prev_top_at_mark_start; 267 HeapWord* _next_top_at_mark_start; 268 // If a collection pause is in progress, this is the top at the start 269 // of that pause. 270 271 void init_top_at_mark_start() { 272 assert(_prev_marked_bytes == 0 && 273 _next_marked_bytes == 0, 274 "Must be called after zero_marked_bytes."); 275 HeapWord* bot = bottom(); 276 _prev_top_at_mark_start = bot; 277 _next_top_at_mark_start = bot; 278 } 279 280 // Cached attributes used in the collection set policy information 281 282 // The RSet length that was added to the total value 283 // for the collection set. 284 size_t _recorded_rs_length; 285 286 // The predicted elapsed time that was added to total value 287 // for the collection set. 288 double _predicted_elapsed_time_ms; 289 290 // Iterate over the references in a humongous objects and apply the given closure 291 // to them. 292 // Humongous objects are allocated directly in the old-gen. So we need special 293 // handling for concurrent processing encountering an in-progress allocation. 294 template <class Closure, bool is_gc_active> 295 inline bool do_oops_on_card_in_humongous(MemRegion mr, 296 Closure* cl, 297 G1CollectedHeap* g1h); 298 299 // Returns the block size of the given (dead, potentially having its class unloaded) object 300 // starting at p extending to at most the prev TAMS using the given mark bitmap. 301 inline size_t block_size_using_bitmap(const HeapWord* p, const G1CMBitMap* const prev_bitmap) const; 302 public: 303 HeapRegion(uint hrm_index, 304 G1BlockOffsetTable* bot, 305 MemRegion mr); 306 307 // Initializing the HeapRegion not only resets the data structure, but also 308 // resets the BOT for that heap region. 309 // The default values for clear_space means that we will do the clearing if 310 // there's clearing to be done ourselves. We also always mangle the space. 311 virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 312 313 static int LogOfHRGrainBytes; 314 static int LogOfHRGrainWords; 315 316 static size_t GrainBytes; 317 static size_t GrainWords; 318 static size_t CardsPerRegion; 319 320 static size_t align_up_to_region_byte_size(size_t sz) { 321 return (sz + (size_t) GrainBytes - 1) & 322 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 323 } 324 325 326 // Returns whether a field is in the same region as the obj it points to. 327 template <typename T> 328 static bool is_in_same_region(T* p, oop obj) { 329 assert(p != NULL, "p can't be NULL"); 330 assert(obj != NULL, "obj can't be NULL"); 331 return (((uintptr_t) p ^ cast_from_oop<uintptr_t>(obj)) >> LogOfHRGrainBytes) == 0; 332 } 333 334 static size_t max_region_size(); 335 static size_t min_region_size_in_words(); 336 337 // It sets up the heap region size (GrainBytes / GrainWords), as 338 // well as other related fields that are based on the heap region 339 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 340 // CardsPerRegion). All those fields are considered constant 341 // throughout the JVM's execution, therefore they should only be set 342 // up once during initialization time. 343 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 344 345 // All allocated blocks are occupied by objects in a HeapRegion 346 bool block_is_obj(const HeapWord* p) const; 347 348 // Returns whether the given object is dead based on TAMS and bitmap. 349 bool is_obj_dead(const oop obj, const G1CMBitMap* const prev_bitmap) const; 350 351 // Returns the object size for all valid block starts 352 // and the amount of unallocated words if called on top() 353 size_t block_size(const HeapWord* p) const; 354 355 // Scans through the region using the bitmap to determine what 356 // objects to call size_t ApplyToMarkedClosure::apply(oop) for. 357 template<typename ApplyToMarkedClosure> 358 inline void apply_to_marked_objects(G1CMBitMap* bitmap, ApplyToMarkedClosure* closure); 359 // Override for scan_and_forward support. 360 void prepare_for_compaction(CompactPoint* cp); 361 // Update heap region to be consistent after compaction. 362 void complete_compaction(); 363 364 inline HeapWord* par_allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* word_size); 365 inline HeapWord* allocate_no_bot_updates(size_t word_size); 366 inline HeapWord* allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* actual_size); 367 368 // If this region is a member of a HeapRegionManager, the index in that 369 // sequence, otherwise -1. 370 uint hrm_index() const { return _hrm_index; } 371 372 // The number of bytes marked live in the region in the last marking phase. 373 size_t marked_bytes() { return _prev_marked_bytes; } 374 size_t live_bytes() { 375 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 376 } 377 378 // The number of bytes counted in the next marking. 379 size_t next_marked_bytes() { return _next_marked_bytes; } 380 // The number of bytes live wrt the next marking. 381 size_t next_live_bytes() { 382 return 383 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 384 } 385 386 // A lower bound on the amount of garbage bytes in the region. 387 size_t garbage_bytes() { 388 size_t used_at_mark_start_bytes = 389 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 390 return used_at_mark_start_bytes - marked_bytes(); 391 } 392 393 // Return the amount of bytes we'll reclaim if we collect this 394 // region. This includes not only the known garbage bytes in the 395 // region but also any unallocated space in it, i.e., [top, end), 396 // since it will also be reclaimed if we collect the region. 397 size_t reclaimable_bytes() { 398 size_t known_live_bytes = live_bytes(); 399 assert(known_live_bytes <= capacity(), "sanity"); 400 return capacity() - known_live_bytes; 401 } 402 403 // An upper bound on the number of live bytes in the region. 404 size_t max_live_bytes() { return used() - garbage_bytes(); } 405 406 void add_to_marked_bytes(size_t incr_bytes) { 407 _next_marked_bytes = _next_marked_bytes + incr_bytes; 408 } 409 410 void zero_marked_bytes() { 411 _prev_marked_bytes = _next_marked_bytes = 0; 412 } 413 414 const char* get_type_str() const { return _type.get_str(); } 415 const char* get_short_type_str() const { return _type.get_short_str(); } 416 G1HeapRegionTraceType::Type get_trace_type() { return _type.get_trace_type(); } 417 418 bool is_free() const { return _type.is_free(); } 419 420 bool is_young() const { return _type.is_young(); } 421 bool is_eden() const { return _type.is_eden(); } 422 bool is_survivor() const { return _type.is_survivor(); } 423 424 bool is_humongous() const { return _type.is_humongous(); } 425 bool is_starts_humongous() const { return _type.is_starts_humongous(); } 426 bool is_continues_humongous() const { return _type.is_continues_humongous(); } 427 428 bool is_old() const { return _type.is_old(); } 429 430 bool is_old_or_humongous() const { return _type.is_old_or_humongous(); } 431 432 bool is_old_or_humongous_or_archive() const { return _type.is_old_or_humongous_or_archive(); } 433 434 // A pinned region contains objects which are not moved by garbage collections. 435 // Humongous regions and archive regions are pinned. 436 bool is_pinned() const { return _type.is_pinned(); } 437 438 // An archive region is a pinned region, also tagged as old, which 439 // should not be marked during mark/sweep. This allows the address 440 // space to be shared by JVM instances. 441 bool is_archive() const { return _type.is_archive(); } 442 bool is_open_archive() const { return _type.is_open_archive(); } 443 bool is_closed_archive() const { return _type.is_closed_archive(); } 444 445 // For a humongous region, region in which it starts. 446 HeapRegion* humongous_start_region() const { 447 return _humongous_start_region; 448 } 449 450 // Makes the current region be a "starts humongous" region, i.e., 451 // the first region in a series of one or more contiguous regions 452 // that will contain a single "humongous" object. 453 // 454 // obj_top : points to the top of the humongous object. 455 // fill_size : size of the filler object at the end of the region series. 456 void set_starts_humongous(HeapWord* obj_top, size_t fill_size); 457 458 // Makes the current region be a "continues humongous' 459 // region. first_hr is the "start humongous" region of the series 460 // which this region will be part of. 461 void set_continues_humongous(HeapRegion* first_hr); 462 463 // Unsets the humongous-related fields on the region. 464 void clear_humongous(); 465 466 // If the region has a remembered set, return a pointer to it. 467 HeapRegionRemSet* rem_set() const { 468 return _rem_set; 469 } 470 471 inline bool in_collection_set() const; 472 473 // Methods used by the HeapRegionSetBase class and subclasses. 474 475 // Getter and setter for the next and prev fields used to link regions into 476 // linked lists. 477 HeapRegion* next() { return _next; } 478 HeapRegion* prev() { return _prev; } 479 480 void set_next(HeapRegion* next) { _next = next; } 481 void set_prev(HeapRegion* prev) { _prev = prev; } 482 483 // Every region added to a set is tagged with a reference to that 484 // set. This is used for doing consistency checking to make sure that 485 // the contents of a set are as they should be and it's only 486 // available in non-product builds. 487 #ifdef ASSERT 488 void set_containing_set(HeapRegionSetBase* containing_set) { 489 assert((containing_set == NULL && _containing_set != NULL) || 490 (containing_set != NULL && _containing_set == NULL), 491 "containing_set: " PTR_FORMAT " " 492 "_containing_set: " PTR_FORMAT, 493 p2i(containing_set), p2i(_containing_set)); 494 495 _containing_set = containing_set; 496 } 497 498 HeapRegionSetBase* containing_set() { return _containing_set; } 499 #else // ASSERT 500 void set_containing_set(HeapRegionSetBase* containing_set) { } 501 502 // containing_set() is only used in asserts so there's no reason 503 // to provide a dummy version of it. 504 #endif // ASSERT 505 506 507 // Reset the HeapRegion to default values. 508 // If skip_remset is true, do not clear the remembered set. 509 // If clear_space is true, clear the HeapRegion's memory. 510 // If locked is true, assume we are the only thread doing this operation. 511 void hr_clear(bool skip_remset, bool clear_space, bool locked = false); 512 // Clear the card table corresponding to this region. 513 void clear_cardtable(); 514 515 // Get the start of the unmarked area in this region. 516 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 517 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 518 519 // Note the start or end of marking. This tells the heap region 520 // that the collector is about to start or has finished (concurrently) 521 // marking the heap. 522 523 // Notify the region that concurrent marking is starting. Initialize 524 // all fields related to the next marking info. 525 inline void note_start_of_marking(); 526 527 // Notify the region that concurrent marking has finished. Copy the 528 // (now finalized) next marking info fields into the prev marking 529 // info fields. 530 inline void note_end_of_marking(); 531 532 // Notify the region that we are about to start processing 533 // self-forwarded objects during evac failure handling. 534 void note_self_forwarding_removal_start(bool during_initial_mark, 535 bool during_conc_mark); 536 537 // Notify the region that we have finished processing self-forwarded 538 // objects during evac failure handling. 539 void note_self_forwarding_removal_end(size_t marked_bytes); 540 541 void reset_during_compaction() { 542 assert(is_humongous(), 543 "should only be called for humongous regions"); 544 545 zero_marked_bytes(); 546 init_top_at_mark_start(); 547 } 548 549 void calc_gc_efficiency(void); 550 double gc_efficiency() { return _gc_efficiency;} 551 552 uint index_in_opt_cset() const { return _index_in_opt_cset; } 553 void set_index_in_opt_cset(uint index) { _index_in_opt_cset = index; } 554 555 int young_index_in_cset() const { return _young_index_in_cset; } 556 void set_young_index_in_cset(int index) { 557 assert( (index == -1) || is_young(), "pre-condition" ); 558 _young_index_in_cset = index; 559 } 560 561 int age_in_surv_rate_group() { 562 assert( _surv_rate_group != NULL, "pre-condition" ); 563 assert( _age_index > -1, "pre-condition" ); 564 return _surv_rate_group->age_in_group(_age_index); 565 } 566 567 void record_surv_words_in_group(size_t words_survived) { 568 assert( _surv_rate_group != NULL, "pre-condition" ); 569 assert( _age_index > -1, "pre-condition" ); 570 int age_in_group = age_in_surv_rate_group(); 571 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 572 } 573 574 int age_in_surv_rate_group_cond() { 575 if (_surv_rate_group != NULL) 576 return age_in_surv_rate_group(); 577 else 578 return -1; 579 } 580 581 SurvRateGroup* surv_rate_group() { 582 return _surv_rate_group; 583 } 584 585 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 586 assert( surv_rate_group != NULL, "pre-condition" ); 587 assert( _surv_rate_group == NULL, "pre-condition" ); 588 assert( is_young(), "pre-condition" ); 589 590 _surv_rate_group = surv_rate_group; 591 _age_index = surv_rate_group->next_age_index(); 592 } 593 594 void uninstall_surv_rate_group() { 595 if (_surv_rate_group != NULL) { 596 assert( _age_index > -1, "pre-condition" ); 597 assert( is_young(), "pre-condition" ); 598 599 _surv_rate_group = NULL; 600 _age_index = -1; 601 } else { 602 assert( _age_index == -1, "pre-condition" ); 603 } 604 } 605 606 void set_free(); 607 608 void set_eden(); 609 void set_eden_pre_gc(); 610 void set_survivor(); 611 612 void move_to_old(); 613 void set_old(); 614 615 void set_open_archive(); 616 void set_closed_archive(); 617 618 // Determine if an object has been allocated since the last 619 // mark performed by the collector. This returns true iff the object 620 // is within the unmarked area of the region. 621 bool obj_allocated_since_prev_marking(oop obj) const { 622 return (HeapWord *) obj >= prev_top_at_mark_start(); 623 } 624 bool obj_allocated_since_next_marking(oop obj) const { 625 return (HeapWord *) obj >= next_top_at_mark_start(); 626 } 627 628 // Returns the "evacuation_failed" property of the region. 629 bool evacuation_failed() { return _evacuation_failed; } 630 631 // Sets the "evacuation_failed" property of the region. 632 void set_evacuation_failed(bool b) { 633 _evacuation_failed = b; 634 635 if (b) { 636 _next_marked_bytes = 0; 637 } 638 } 639 640 // Iterate over the objects overlapping part of a card, applying cl 641 // to all references in the region. This is a helper for 642 // G1RemSet::refine_card*, and is tightly coupled with them. 643 // mr is the memory region covered by the card, trimmed to the 644 // allocated space for this region. Must not be empty. 645 // This region must be old or humongous. 646 // Returns true if the designated objects were successfully 647 // processed, false if an unparsable part of the heap was 648 // encountered; that only happens when invoked concurrently with the 649 // mutator. 650 template <bool is_gc_active, class Closure> 651 inline bool oops_on_card_seq_iterate_careful(MemRegion mr, Closure* cl); 652 653 size_t recorded_rs_length() const { return _recorded_rs_length; } 654 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 655 656 void set_recorded_rs_length(size_t rs_length) { 657 _recorded_rs_length = rs_length; 658 } 659 660 void set_predicted_elapsed_time_ms(double ms) { 661 _predicted_elapsed_time_ms = ms; 662 } 663 664 // Routines for managing a list of code roots (attached to the 665 // this region's RSet) that point into this heap region. 666 void add_strong_code_root(nmethod* nm); 667 void add_strong_code_root_locked(nmethod* nm); 668 void remove_strong_code_root(nmethod* nm); 669 670 // Applies blk->do_code_blob() to each of the entries in 671 // the strong code roots list for this region 672 void strong_code_roots_do(CodeBlobClosure* blk) const; 673 674 // Verify that the entries on the strong code root list for this 675 // region are live and include at least one pointer into this region. 676 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 677 678 void print() const; 679 void print_on(outputStream* st) const; 680 681 // vo == UsePrevMarking -> use "prev" marking information, 682 // vo == UseNextMarking -> use "next" marking information 683 // vo == UseFullMarking -> use "next" marking bitmap but no TAMS 684 // 685 // NOTE: Only the "prev" marking information is guaranteed to be 686 // consistent most of the time, so most calls to this should use 687 // vo == UsePrevMarking. 688 // Currently, there is only one case where this is called with 689 // vo == UseNextMarking, which is to verify the "next" marking 690 // information at the end of remark. 691 // Currently there is only one place where this is called with 692 // vo == UseFullMarking, which is to verify the marking during a 693 // full GC. 694 void verify(VerifyOption vo, bool *failures) const; 695 696 // Override; it uses the "prev" marking information 697 virtual void verify() const; 698 699 void verify_rem_set(VerifyOption vo, bool *failures) const; 700 void verify_rem_set() const; 701 }; 702 703 // HeapRegionClosure is used for iterating over regions. 704 // Terminates the iteration when the "do_heap_region" method returns "true". 705 class HeapRegionClosure : public StackObj { 706 friend class HeapRegionManager; 707 friend class G1CollectionSet; 708 friend class CollectionSetChooser; 709 710 bool _is_complete; 711 void set_incomplete() { _is_complete = false; } 712 713 public: 714 HeapRegionClosure(): _is_complete(true) {} 715 716 // Typically called on each region until it returns true. 717 virtual bool do_heap_region(HeapRegion* r) = 0; 718 719 // True after iteration if the closure was applied to all heap regions 720 // and returned "false" in all cases. 721 bool is_complete() { return _is_complete; } 722 }; 723 724 #endif // SHARE_GC_G1_HEAPREGION_HPP