1 /* 2 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP 27 28 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp" 29 #include "gc_implementation/g1/g1_specialized_oop_closures.hpp" 30 #include "gc_implementation/g1/survRateGroup.hpp" 31 #include "gc_implementation/shared/ageTable.hpp" 32 #include "gc_implementation/shared/spaceDecorator.hpp" 33 #include "memory/space.inline.hpp" 34 #include "memory/watermark.hpp" 35 36 #ifndef SERIALGC 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 class CompactibleSpace; 49 class ContiguousSpace; 50 class HeapRegionRemSet; 51 class HeapRegionRemSetIterator; 52 class HeapRegion; 53 54 // A dirty card to oop closure for heap regions. It 55 // knows how to get the G1 heap and how to use the bitmap 56 // in the concurrent marker used by G1 to filter remembered 57 // sets. 58 59 class HeapRegionDCTOC : public ContiguousSpaceDCTOC { 60 public: 61 // Specification of possible DirtyCardToOopClosure filtering. 62 enum FilterKind { 63 NoFilterKind, 64 IntoCSFilterKind, 65 OutOfRegionFilterKind 66 }; 67 68 protected: 69 HeapRegion* _hr; 70 FilterKind _fk; 71 G1CollectedHeap* _g1; 72 73 void walk_mem_region_with_cl(MemRegion mr, 74 HeapWord* bottom, HeapWord* top, 75 OopClosure* cl); 76 77 // We don't specialize this for FilteringClosure; filtering is handled by 78 // the "FilterKind" mechanism. But we provide this to avoid a compiler 79 // warning. 80 void walk_mem_region_with_cl(MemRegion mr, 81 HeapWord* bottom, HeapWord* top, 82 FilteringClosure* cl) { 83 HeapRegionDCTOC::walk_mem_region_with_cl(mr, bottom, top, 84 (OopClosure*)cl); 85 } 86 87 // Get the actual top of the area on which the closure will 88 // operate, given where the top is assumed to be (the end of the 89 // memory region passed to do_MemRegion) and where the object 90 // at the top is assumed to start. For example, an object may 91 // start at the top but actually extend past the assumed top, 92 // in which case the top becomes the end of the object. 93 HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj) { 94 return ContiguousSpaceDCTOC::get_actual_top(top, top_obj); 95 } 96 97 // Walk the given memory region from bottom to (actual) top 98 // looking for objects and applying the oop closure (_cl) to 99 // them. The base implementation of this treats the area as 100 // blocks, where a block may or may not be an object. Sub- 101 // classes should override this to provide more accurate 102 // or possibly more efficient walking. 103 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top) { 104 Filtering_DCTOC::walk_mem_region(mr, bottom, top); 105 } 106 107 public: 108 HeapRegionDCTOC(G1CollectedHeap* g1, 109 HeapRegion* hr, OopClosure* cl, 110 CardTableModRefBS::PrecisionStyle precision, 111 FilterKind fk); 112 }; 113 114 115 // The complicating factor is that BlockOffsetTable diverged 116 // significantly, and we need functionality that is only in the G1 version. 117 // So I copied that code, which led to an alternate G1 version of 118 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could 119 // be reconciled, then G1OffsetTableContigSpace could go away. 120 121 // The idea behind time stamps is the following. Doing a save_marks on 122 // all regions at every GC pause is time consuming (if I remember 123 // well, 10ms or so). So, we would like to do that only for regions 124 // that are GC alloc regions. To achieve this, we use time 125 // stamps. For every evacuation pause, G1CollectedHeap generates a 126 // unique time stamp (essentially a counter that gets 127 // incremented). Every time we want to call save_marks on a region, 128 // we set the saved_mark_word to top and also copy the current GC 129 // time stamp to the time stamp field of the space. Reading the 130 // saved_mark_word involves checking the time stamp of the 131 // region. If it is the same as the current GC time stamp, then we 132 // can safely read the saved_mark_word field, as it is valid. If the 133 // time stamp of the region is not the same as the current GC time 134 // stamp, then we instead read top, as the saved_mark_word field is 135 // invalid. Time stamps (on the regions and also on the 136 // G1CollectedHeap) are reset at every cleanup (we iterate over 137 // the regions anyway) and at the end of a Full GC. The current scheme 138 // that uses sequential unsigned ints will fail only if we have 4b 139 // evacuation pauses between two cleanups, which is _highly_ unlikely. 140 141 class G1OffsetTableContigSpace: public ContiguousSpace { 142 friend class VMStructs; 143 protected: 144 G1BlockOffsetArrayContigSpace _offsets; 145 Mutex _par_alloc_lock; 146 volatile unsigned _gc_time_stamp; 147 148 public: 149 // Constructor. If "is_zeroed" is true, the MemRegion "mr" may be 150 // assumed to contain zeros. 151 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray, 152 MemRegion mr, bool is_zeroed = false); 153 154 void set_bottom(HeapWord* value); 155 void set_end(HeapWord* value); 156 157 virtual HeapWord* saved_mark_word() const; 158 virtual void set_saved_mark(); 159 void reset_gc_time_stamp() { _gc_time_stamp = 0; } 160 161 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); 162 virtual void clear(bool mangle_space); 163 164 HeapWord* block_start(const void* p); 165 HeapWord* block_start_const(const void* p) const; 166 167 // Add offset table update. 168 virtual HeapWord* allocate(size_t word_size); 169 HeapWord* par_allocate(size_t word_size); 170 171 // MarkSweep support phase3 172 virtual HeapWord* initialize_threshold(); 173 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 174 175 virtual void print() const; 176 }; 177 178 class HeapRegion: public G1OffsetTableContigSpace { 179 friend class VMStructs; 180 private: 181 182 enum HumongousType { 183 NotHumongous = 0, 184 StartsHumongous, 185 ContinuesHumongous 186 }; 187 188 // The next filter kind that should be used for a "new_dcto_cl" call with 189 // the "traditional" signature. 190 HeapRegionDCTOC::FilterKind _next_fk; 191 192 // Requires that the region "mr" be dense with objects, and begin and end 193 // with an object. 194 void oops_in_mr_iterate(MemRegion mr, OopClosure* cl); 195 196 // The remembered set for this region. 197 // (Might want to make this "inline" later, to avoid some alloc failure 198 // issues.) 199 HeapRegionRemSet* _rem_set; 200 201 G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; } 202 203 protected: 204 // If this region is a member of a HeapRegionSeq, the index in that 205 // sequence, otherwise -1. 206 int _hrs_index; 207 208 HumongousType _humongous_type; 209 // For a humongous region, region in which it starts. 210 HeapRegion* _humongous_start_region; 211 // For the start region of a humongous sequence, it's original end(). 212 HeapWord* _orig_end; 213 214 // True iff the region is in current collection_set. 215 bool _in_collection_set; 216 217 // True iff the region is on the unclean list, waiting to be zero filled. 218 bool _is_on_unclean_list; 219 220 // True iff the region is on the free list, ready for allocation. 221 bool _is_on_free_list; 222 223 // Is this or has it been an allocation region in the current collection 224 // pause. 225 bool _is_gc_alloc_region; 226 227 // True iff an attempt to evacuate an object in the region failed. 228 bool _evacuation_failed; 229 230 // A heap region may be a member one of a number of special subsets, each 231 // represented as linked lists through the field below. Currently, these 232 // sets include: 233 // The collection set. 234 // The set of allocation regions used in a collection pause. 235 // Spaces that may contain gray objects. 236 HeapRegion* _next_in_special_set; 237 238 // next region in the young "generation" region set 239 HeapRegion* _next_young_region; 240 241 // Next region whose cards need cleaning 242 HeapRegion* _next_dirty_cards_region; 243 244 // For parallel heapRegion traversal. 245 jint _claimed; 246 247 // We use concurrent marking to determine the amount of live data 248 // in each heap region. 249 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 250 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 251 252 // See "sort_index" method. -1 means is not in the array. 253 int _sort_index; 254 255 // <PREDICTION> 256 double _gc_efficiency; 257 // </PREDICTION> 258 259 enum YoungType { 260 NotYoung, // a region is not young 261 Young, // a region is young 262 Survivor // a region is young and it contains 263 // survivor 264 }; 265 266 volatile YoungType _young_type; 267 int _young_index_in_cset; 268 SurvRateGroup* _surv_rate_group; 269 int _age_index; 270 271 // The start of the unmarked area. The unmarked area extends from this 272 // word until the top and/or end of the region, and is the part 273 // of the region for which no marking was done, i.e. objects may 274 // have been allocated in this part since the last mark phase. 275 // "prev" is the top at the start of the last completed marking. 276 // "next" is the top at the start of the in-progress marking (if any.) 277 HeapWord* _prev_top_at_mark_start; 278 HeapWord* _next_top_at_mark_start; 279 // If a collection pause is in progress, this is the top at the start 280 // of that pause. 281 282 // We've counted the marked bytes of objects below here. 283 HeapWord* _top_at_conc_mark_count; 284 285 void init_top_at_mark_start() { 286 assert(_prev_marked_bytes == 0 && 287 _next_marked_bytes == 0, 288 "Must be called after zero_marked_bytes."); 289 HeapWord* bot = bottom(); 290 _prev_top_at_mark_start = bot; 291 _next_top_at_mark_start = bot; 292 _top_at_conc_mark_count = bot; 293 } 294 295 jint _zfs; // A member of ZeroFillState. Protected by ZF_lock. 296 Thread* _zero_filler; // If _zfs is ZeroFilling, the thread that (last) 297 // made it so. 298 299 void set_young_type(YoungType new_type) { 300 //assert(_young_type != new_type, "setting the same type" ); 301 // TODO: add more assertions here 302 _young_type = new_type; 303 } 304 305 // Cached attributes used in the collection set policy information 306 307 // The RSet length that was added to the total value 308 // for the collection set. 309 size_t _recorded_rs_length; 310 311 // The predicted elapsed time that was added to total value 312 // for the collection set. 313 double _predicted_elapsed_time_ms; 314 315 // The predicted number of bytes to copy that was added to 316 // the total value for the collection set. 317 size_t _predicted_bytes_to_copy; 318 319 public: 320 // If "is_zeroed" is "true", the region "mr" can be assumed to contain zeros. 321 HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray, 322 MemRegion mr, bool is_zeroed); 323 324 static int LogOfHRGrainBytes; 325 static int LogOfHRGrainWords; 326 // The normal type of these should be size_t. However, they used to 327 // be members of an enum before and they are assumed by the 328 // compilers to be ints. To avoid going and fixing all their uses, 329 // I'm declaring them as ints. I'm not anticipating heap region 330 // sizes to reach anywhere near 2g, so using an int here is safe. 331 static int GrainBytes; 332 static int GrainWords; 333 static int CardsPerRegion; 334 335 // It sets up the heap region size (GrainBytes / GrainWords), as 336 // well as other related fields that are based on the heap region 337 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 338 // CardsPerRegion). All those fields are considered constant 339 // throughout the JVM's execution, therefore they should only be set 340 // up once during initialization time. 341 static void setup_heap_region_size(uintx min_heap_size); 342 343 enum ClaimValues { 344 InitialClaimValue = 0, 345 FinalCountClaimValue = 1, 346 NoteEndClaimValue = 2, 347 ScrubRemSetClaimValue = 3, 348 ParVerifyClaimValue = 4, 349 RebuildRSClaimValue = 5 350 }; 351 352 // Concurrent refinement requires contiguous heap regions (in which TLABs 353 // might be allocated) to be zero-filled. Each region therefore has a 354 // zero-fill-state. 355 enum ZeroFillState { 356 NotZeroFilled, 357 ZeroFilling, 358 ZeroFilled, 359 Allocated 360 }; 361 362 // If this region is a member of a HeapRegionSeq, the index in that 363 // sequence, otherwise -1. 364 int hrs_index() const { return _hrs_index; } 365 void set_hrs_index(int index) { _hrs_index = index; } 366 367 // The number of bytes marked live in the region in the last marking phase. 368 size_t marked_bytes() { return _prev_marked_bytes; } 369 // The number of bytes counted in the next marking. 370 size_t next_marked_bytes() { return _next_marked_bytes; } 371 // The number of bytes live wrt the next marking. 372 size_t next_live_bytes() { 373 return (top() - next_top_at_mark_start()) 374 * HeapWordSize 375 + next_marked_bytes(); 376 } 377 378 // A lower bound on the amount of garbage bytes in the region. 379 size_t garbage_bytes() { 380 size_t used_at_mark_start_bytes = 381 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 382 assert(used_at_mark_start_bytes >= marked_bytes(), 383 "Can't mark more than we have."); 384 return used_at_mark_start_bytes - marked_bytes(); 385 } 386 387 // An upper bound on the number of live bytes in the region. 388 size_t max_live_bytes() { return used() - garbage_bytes(); } 389 390 void add_to_marked_bytes(size_t incr_bytes) { 391 _next_marked_bytes = _next_marked_bytes + incr_bytes; 392 guarantee( _next_marked_bytes <= used(), "invariant" ); 393 } 394 395 void zero_marked_bytes() { 396 _prev_marked_bytes = _next_marked_bytes = 0; 397 } 398 399 bool isHumongous() const { return _humongous_type != NotHumongous; } 400 bool startsHumongous() const { return _humongous_type == StartsHumongous; } 401 bool continuesHumongous() const { return _humongous_type == ContinuesHumongous; } 402 // For a humongous region, region in which it starts. 403 HeapRegion* humongous_start_region() const { 404 return _humongous_start_region; 405 } 406 407 // Causes the current region to represent a humongous object spanning "n" 408 // regions. 409 virtual void set_startsHumongous(); 410 411 // The regions that continue a humongous sequence should be added using 412 // this method, in increasing address order. 413 void set_continuesHumongous(HeapRegion* start); 414 415 void add_continuingHumongousRegion(HeapRegion* cont); 416 417 // If the region has a remembered set, return a pointer to it. 418 HeapRegionRemSet* rem_set() const { 419 return _rem_set; 420 } 421 422 // True iff the region is in current collection_set. 423 bool in_collection_set() const { 424 return _in_collection_set; 425 } 426 void set_in_collection_set(bool b) { 427 _in_collection_set = b; 428 } 429 HeapRegion* next_in_collection_set() { 430 assert(in_collection_set(), "should only invoke on member of CS."); 431 assert(_next_in_special_set == NULL || 432 _next_in_special_set->in_collection_set(), 433 "Malformed CS."); 434 return _next_in_special_set; 435 } 436 void set_next_in_collection_set(HeapRegion* r) { 437 assert(in_collection_set(), "should only invoke on member of CS."); 438 assert(r == NULL || r->in_collection_set(), "Malformed CS."); 439 _next_in_special_set = r; 440 } 441 442 // True iff it is or has been an allocation region in the current 443 // collection pause. 444 bool is_gc_alloc_region() const { 445 return _is_gc_alloc_region; 446 } 447 void set_is_gc_alloc_region(bool b) { 448 _is_gc_alloc_region = b; 449 } 450 HeapRegion* next_gc_alloc_region() { 451 assert(is_gc_alloc_region(), "should only invoke on member of CS."); 452 assert(_next_in_special_set == NULL || 453 _next_in_special_set->is_gc_alloc_region(), 454 "Malformed CS."); 455 return _next_in_special_set; 456 } 457 void set_next_gc_alloc_region(HeapRegion* r) { 458 assert(is_gc_alloc_region(), "should only invoke on member of CS."); 459 assert(r == NULL || r->is_gc_alloc_region(), "Malformed CS."); 460 _next_in_special_set = r; 461 } 462 463 bool is_on_free_list() { 464 return _is_on_free_list; 465 } 466 467 void set_on_free_list(bool b) { 468 _is_on_free_list = b; 469 } 470 471 HeapRegion* next_from_free_list() { 472 assert(is_on_free_list(), 473 "Should only invoke on free space."); 474 assert(_next_in_special_set == NULL || 475 _next_in_special_set->is_on_free_list(), 476 "Malformed Free List."); 477 return _next_in_special_set; 478 } 479 480 void set_next_on_free_list(HeapRegion* r) { 481 assert(r == NULL || r->is_on_free_list(), "Malformed free list."); 482 _next_in_special_set = r; 483 } 484 485 bool is_on_unclean_list() { 486 return _is_on_unclean_list; 487 } 488 489 void set_on_unclean_list(bool b); 490 491 HeapRegion* next_from_unclean_list() { 492 assert(is_on_unclean_list(), 493 "Should only invoke on unclean space."); 494 assert(_next_in_special_set == NULL || 495 _next_in_special_set->is_on_unclean_list(), 496 "Malformed unclean List."); 497 return _next_in_special_set; 498 } 499 500 void set_next_on_unclean_list(HeapRegion* r); 501 502 HeapRegion* get_next_young_region() { return _next_young_region; } 503 void set_next_young_region(HeapRegion* hr) { 504 _next_young_region = hr; 505 } 506 507 HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; } 508 HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; } 509 void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; } 510 bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; } 511 512 // Allows logical separation between objects allocated before and after. 513 void save_marks(); 514 515 // Reset HR stuff to default values. 516 void hr_clear(bool par, bool clear_space); 517 518 void initialize(MemRegion mr, bool clear_space, bool mangle_space); 519 520 // Ensure that "this" is zero-filled. 521 void ensure_zero_filled(); 522 // This one requires that the calling thread holds ZF_mon. 523 void ensure_zero_filled_locked(); 524 525 // Get the start of the unmarked area in this region. 526 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 527 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 528 529 // Apply "cl->do_oop" to (the addresses of) all reference fields in objects 530 // allocated in the current region before the last call to "save_mark". 531 void oop_before_save_marks_iterate(OopClosure* cl); 532 533 // This call determines the "filter kind" argument that will be used for 534 // the next call to "new_dcto_cl" on this region with the "traditional" 535 // signature (i.e., the call below.) The default, in the absence of a 536 // preceding call to this method, is "NoFilterKind", and a call to this 537 // method is necessary for each such call, or else it reverts to the 538 // default. 539 // (This is really ugly, but all other methods I could think of changed a 540 // lot of main-line code for G1.) 541 void set_next_filter_kind(HeapRegionDCTOC::FilterKind nfk) { 542 _next_fk = nfk; 543 } 544 545 DirtyCardToOopClosure* 546 new_dcto_closure(OopClosure* cl, 547 CardTableModRefBS::PrecisionStyle precision, 548 HeapRegionDCTOC::FilterKind fk); 549 550 #if WHASSUP 551 DirtyCardToOopClosure* 552 new_dcto_closure(OopClosure* cl, 553 CardTableModRefBS::PrecisionStyle precision, 554 HeapWord* boundary) { 555 assert(boundary == NULL, "This arg doesn't make sense here."); 556 DirtyCardToOopClosure* res = new_dcto_closure(cl, precision, _next_fk); 557 _next_fk = HeapRegionDCTOC::NoFilterKind; 558 return res; 559 } 560 #endif 561 562 // 563 // Note the start or end of marking. This tells the heap region 564 // that the collector is about to start or has finished (concurrently) 565 // marking the heap. 566 // 567 568 // Note the start of a marking phase. Record the 569 // start of the unmarked area of the region here. 570 void note_start_of_marking(bool during_initial_mark) { 571 init_top_at_conc_mark_count(); 572 _next_marked_bytes = 0; 573 if (during_initial_mark && is_young() && !is_survivor()) 574 _next_top_at_mark_start = bottom(); 575 else 576 _next_top_at_mark_start = top(); 577 } 578 579 // Note the end of a marking phase. Install the start of 580 // the unmarked area that was captured at start of marking. 581 void note_end_of_marking() { 582 _prev_top_at_mark_start = _next_top_at_mark_start; 583 _prev_marked_bytes = _next_marked_bytes; 584 _next_marked_bytes = 0; 585 586 guarantee(_prev_marked_bytes <= 587 (size_t) (prev_top_at_mark_start() - bottom()) * HeapWordSize, 588 "invariant"); 589 } 590 591 // After an evacuation, we need to update _next_top_at_mark_start 592 // to be the current top. Note this is only valid if we have only 593 // ever evacuated into this region. If we evacuate, allocate, and 594 // then evacuate we are in deep doodoo. 595 void note_end_of_copying() { 596 assert(top() >= _next_top_at_mark_start, "Increase only"); 597 _next_top_at_mark_start = top(); 598 } 599 600 // Returns "false" iff no object in the region was allocated when the 601 // last mark phase ended. 602 bool is_marked() { return _prev_top_at_mark_start != bottom(); } 603 604 // If "is_marked()" is true, then this is the index of the region in 605 // an array constructed at the end of marking of the regions in a 606 // "desirability" order. 607 int sort_index() { 608 return _sort_index; 609 } 610 void set_sort_index(int i) { 611 _sort_index = i; 612 } 613 614 void init_top_at_conc_mark_count() { 615 _top_at_conc_mark_count = bottom(); 616 } 617 618 void set_top_at_conc_mark_count(HeapWord *cur) { 619 assert(bottom() <= cur && cur <= end(), "Sanity."); 620 _top_at_conc_mark_count = cur; 621 } 622 623 HeapWord* top_at_conc_mark_count() { 624 return _top_at_conc_mark_count; 625 } 626 627 void reset_during_compaction() { 628 guarantee( isHumongous() && startsHumongous(), 629 "should only be called for humongous regions"); 630 631 zero_marked_bytes(); 632 init_top_at_mark_start(); 633 } 634 635 // <PREDICTION> 636 void calc_gc_efficiency(void); 637 double gc_efficiency() { return _gc_efficiency;} 638 // </PREDICTION> 639 640 bool is_young() const { return _young_type != NotYoung; } 641 bool is_survivor() const { return _young_type == Survivor; } 642 643 int young_index_in_cset() const { return _young_index_in_cset; } 644 void set_young_index_in_cset(int index) { 645 assert( (index == -1) || is_young(), "pre-condition" ); 646 _young_index_in_cset = index; 647 } 648 649 int age_in_surv_rate_group() { 650 assert( _surv_rate_group != NULL, "pre-condition" ); 651 assert( _age_index > -1, "pre-condition" ); 652 return _surv_rate_group->age_in_group(_age_index); 653 } 654 655 void record_surv_words_in_group(size_t words_survived) { 656 assert( _surv_rate_group != NULL, "pre-condition" ); 657 assert( _age_index > -1, "pre-condition" ); 658 int age_in_group = age_in_surv_rate_group(); 659 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 660 } 661 662 int age_in_surv_rate_group_cond() { 663 if (_surv_rate_group != NULL) 664 return age_in_surv_rate_group(); 665 else 666 return -1; 667 } 668 669 SurvRateGroup* surv_rate_group() { 670 return _surv_rate_group; 671 } 672 673 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 674 assert( surv_rate_group != NULL, "pre-condition" ); 675 assert( _surv_rate_group == NULL, "pre-condition" ); 676 assert( is_young(), "pre-condition" ); 677 678 _surv_rate_group = surv_rate_group; 679 _age_index = surv_rate_group->next_age_index(); 680 } 681 682 void uninstall_surv_rate_group() { 683 if (_surv_rate_group != NULL) { 684 assert( _age_index > -1, "pre-condition" ); 685 assert( is_young(), "pre-condition" ); 686 687 _surv_rate_group = NULL; 688 _age_index = -1; 689 } else { 690 assert( _age_index == -1, "pre-condition" ); 691 } 692 } 693 694 void set_young() { set_young_type(Young); } 695 696 void set_survivor() { set_young_type(Survivor); } 697 698 void set_not_young() { set_young_type(NotYoung); } 699 700 // Determine if an object has been allocated since the last 701 // mark performed by the collector. This returns true iff the object 702 // is within the unmarked area of the region. 703 bool obj_allocated_since_prev_marking(oop obj) const { 704 return (HeapWord *) obj >= prev_top_at_mark_start(); 705 } 706 bool obj_allocated_since_next_marking(oop obj) const { 707 return (HeapWord *) obj >= next_top_at_mark_start(); 708 } 709 710 // For parallel heapRegion traversal. 711 bool claimHeapRegion(int claimValue); 712 jint claim_value() { return _claimed; } 713 // Use this carefully: only when you're sure no one is claiming... 714 void set_claim_value(int claimValue) { _claimed = claimValue; } 715 716 // Returns the "evacuation_failed" property of the region. 717 bool evacuation_failed() { return _evacuation_failed; } 718 719 // Sets the "evacuation_failed" property of the region. 720 void set_evacuation_failed(bool b) { 721 _evacuation_failed = b; 722 723 if (b) { 724 init_top_at_conc_mark_count(); 725 _next_marked_bytes = 0; 726 } 727 } 728 729 // Requires that "mr" be entirely within the region. 730 // Apply "cl->do_object" to all objects that intersect with "mr". 731 // If the iteration encounters an unparseable portion of the region, 732 // or if "cl->abort()" is true after a closure application, 733 // terminate the iteration and return the address of the start of the 734 // subregion that isn't done. (The two can be distinguished by querying 735 // "cl->abort()".) Return of "NULL" indicates that the iteration 736 // completed. 737 HeapWord* 738 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl); 739 740 // In this version - if filter_young is true and the region 741 // is a young region then we skip the iteration. 742 HeapWord* 743 oops_on_card_seq_iterate_careful(MemRegion mr, 744 FilterOutOfRegionClosure* cl, 745 bool filter_young); 746 747 // The region "mr" is entirely in "this", and starts and ends at block 748 // boundaries. The caller declares that all the contained blocks are 749 // coalesced into one. 750 void declare_filled_region_to_BOT(MemRegion mr) { 751 _offsets.single_block(mr.start(), mr.end()); 752 } 753 754 // A version of block start that is guaranteed to find *some* block 755 // boundary at or before "p", but does not object iteration, and may 756 // therefore be used safely when the heap is unparseable. 757 HeapWord* block_start_careful(const void* p) const { 758 return _offsets.block_start_careful(p); 759 } 760 761 // Requires that "addr" is within the region. Returns the start of the 762 // first ("careful") block that starts at or after "addr", or else the 763 // "end" of the region if there is no such block. 764 HeapWord* next_block_start_careful(HeapWord* addr); 765 766 // Returns the zero-fill-state of the current region. 767 ZeroFillState zero_fill_state() { return (ZeroFillState)_zfs; } 768 bool zero_fill_is_allocated() { return _zfs == Allocated; } 769 Thread* zero_filler() { return _zero_filler; } 770 771 // Indicate that the contents of the region are unknown, and therefore 772 // might require zero-filling. 773 void set_zero_fill_needed() { 774 set_zero_fill_state_work(NotZeroFilled); 775 } 776 void set_zero_fill_in_progress(Thread* t) { 777 set_zero_fill_state_work(ZeroFilling); 778 _zero_filler = t; 779 } 780 void set_zero_fill_complete(); 781 void set_zero_fill_allocated() { 782 set_zero_fill_state_work(Allocated); 783 } 784 785 void set_zero_fill_state_work(ZeroFillState zfs); 786 787 // This is called when a full collection shrinks the heap. 788 // We want to set the heap region to a value which says 789 // it is no longer part of the heap. For now, we'll let "NotZF" fill 790 // that role. 791 void reset_zero_fill() { 792 set_zero_fill_state_work(NotZeroFilled); 793 _zero_filler = NULL; 794 } 795 796 size_t recorded_rs_length() const { return _recorded_rs_length; } 797 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 798 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; } 799 800 void set_recorded_rs_length(size_t rs_length) { 801 _recorded_rs_length = rs_length; 802 } 803 804 void set_predicted_elapsed_time_ms(double ms) { 805 _predicted_elapsed_time_ms = ms; 806 } 807 808 void set_predicted_bytes_to_copy(size_t bytes) { 809 _predicted_bytes_to_copy = bytes; 810 } 811 812 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \ 813 virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl); 814 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DECL) 815 816 CompactibleSpace* next_compaction_space() const; 817 818 virtual void reset_after_compaction(); 819 820 void print() const; 821 void print_on(outputStream* st) const; 822 823 // use_prev_marking == true -> use "prev" marking information, 824 // use_prev_marking == false -> use "next" marking information 825 // NOTE: Only the "prev" marking information is guaranteed to be 826 // consistent most of the time, so most calls to this should use 827 // use_prev_marking == true. Currently, there is only one case where 828 // this is called with use_prev_marking == false, which is to verify 829 // the "next" marking information at the end of remark. 830 void verify(bool allow_dirty, bool use_prev_marking, bool *failures) const; 831 832 // Override; it uses the "prev" marking information 833 virtual void verify(bool allow_dirty) const; 834 835 #ifdef DEBUG 836 HeapWord* allocate(size_t size); 837 #endif 838 }; 839 840 // HeapRegionClosure is used for iterating over regions. 841 // Terminates the iteration when the "doHeapRegion" method returns "true". 842 class HeapRegionClosure : public StackObj { 843 friend class HeapRegionSeq; 844 friend class G1CollectedHeap; 845 846 bool _complete; 847 void incomplete() { _complete = false; } 848 849 public: 850 HeapRegionClosure(): _complete(true) {} 851 852 // Typically called on each region until it returns true. 853 virtual bool doHeapRegion(HeapRegion* r) = 0; 854 855 // True after iteration if the closure was applied to all heap regions 856 // and returned "false" in all cases. 857 bool complete() { return _complete; } 858 }; 859 860 // A linked lists of heap regions. It leaves the "next" field 861 // unspecified; that's up to subtypes. 862 class RegionList VALUE_OBJ_CLASS_SPEC { 863 protected: 864 virtual HeapRegion* get_next(HeapRegion* chr) = 0; 865 virtual void set_next(HeapRegion* chr, 866 HeapRegion* new_next) = 0; 867 868 HeapRegion* _hd; 869 HeapRegion* _tl; 870 size_t _sz; 871 872 // Protected constructor because this type is only meaningful 873 // when the _get/_set next functions are defined. 874 RegionList() : _hd(NULL), _tl(NULL), _sz(0) {} 875 public: 876 void reset() { 877 _hd = NULL; 878 _tl = NULL; 879 _sz = 0; 880 } 881 HeapRegion* hd() { return _hd; } 882 HeapRegion* tl() { return _tl; } 883 size_t sz() { return _sz; } 884 size_t length(); 885 886 bool well_formed() { 887 return 888 ((hd() == NULL && tl() == NULL && sz() == 0) 889 || (hd() != NULL && tl() != NULL && sz() > 0)) 890 && (sz() == length()); 891 } 892 virtual void insert_before_head(HeapRegion* r); 893 void prepend_list(RegionList* new_list); 894 virtual HeapRegion* pop(); 895 void dec_sz() { _sz--; } 896 // Requires that "r" is an element of the list, and is not the tail. 897 void delete_after(HeapRegion* r); 898 }; 899 900 class EmptyNonHRegionList: public RegionList { 901 protected: 902 // Protected constructor because this type is only meaningful 903 // when the _get/_set next functions are defined. 904 EmptyNonHRegionList() : RegionList() {} 905 906 public: 907 void insert_before_head(HeapRegion* r) { 908 // assert(r->is_empty(), "Better be empty"); 909 assert(!r->isHumongous(), "Better not be humongous."); 910 RegionList::insert_before_head(r); 911 } 912 void prepend_list(EmptyNonHRegionList* new_list) { 913 // assert(new_list->hd() == NULL || new_list->hd()->is_empty(), 914 // "Better be empty"); 915 assert(new_list->hd() == NULL || !new_list->hd()->isHumongous(), 916 "Better not be humongous."); 917 // assert(new_list->tl() == NULL || new_list->tl()->is_empty(), 918 // "Better be empty"); 919 assert(new_list->tl() == NULL || !new_list->tl()->isHumongous(), 920 "Better not be humongous."); 921 RegionList::prepend_list(new_list); 922 } 923 }; 924 925 class UncleanRegionList: public EmptyNonHRegionList { 926 public: 927 HeapRegion* get_next(HeapRegion* hr) { 928 return hr->next_from_unclean_list(); 929 } 930 void set_next(HeapRegion* hr, HeapRegion* new_next) { 931 hr->set_next_on_unclean_list(new_next); 932 } 933 934 UncleanRegionList() : EmptyNonHRegionList() {} 935 936 void insert_before_head(HeapRegion* r) { 937 assert(!r->is_on_free_list(), 938 "Better not already be on free list"); 939 assert(!r->is_on_unclean_list(), 940 "Better not already be on unclean list"); 941 r->set_zero_fill_needed(); 942 r->set_on_unclean_list(true); 943 EmptyNonHRegionList::insert_before_head(r); 944 } 945 void prepend_list(UncleanRegionList* new_list) { 946 assert(new_list->tl() == NULL || !new_list->tl()->is_on_free_list(), 947 "Better not already be on free list"); 948 assert(new_list->tl() == NULL || new_list->tl()->is_on_unclean_list(), 949 "Better already be marked as on unclean list"); 950 assert(new_list->hd() == NULL || !new_list->hd()->is_on_free_list(), 951 "Better not already be on free list"); 952 assert(new_list->hd() == NULL || new_list->hd()->is_on_unclean_list(), 953 "Better already be marked as on unclean list"); 954 EmptyNonHRegionList::prepend_list(new_list); 955 } 956 HeapRegion* pop() { 957 HeapRegion* res = RegionList::pop(); 958 if (res != NULL) res->set_on_unclean_list(false); 959 return res; 960 } 961 }; 962 963 // Local Variables: *** 964 // c-indentation-style: gnu *** 965 // End: *** 966 967 #endif // SERIALGC 968 969 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP