1 /* 2 * Copyright (c) 2001, 2017, 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. 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 G1CMBitMapRO; 60 class HeapRegionRemSet; 61 class HeapRegionRemSetIterator; 62 class HeapRegion; 63 class HeapRegionSetBase; 64 class nmethod; 65 66 #define HR_FORMAT "%u:(%s)[" PTR_FORMAT "," PTR_FORMAT "," PTR_FORMAT "]" 67 #define HR_FORMAT_PARAMS(_hr_) \ 68 (_hr_)->hrm_index(), \ 69 (_hr_)->get_short_type_str(), \ 70 p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end()) 71 72 // sentinel value for hrm_index 73 #define G1_NO_HRM_INDEX ((uint) -1) 74 75 // A dirty card to oop closure for heap regions. It 76 // knows how to get the G1 heap and how to use the bitmap 77 // in the concurrent marker used by G1 to filter remembered 78 // sets. 79 80 class HeapRegionDCTOC : public DirtyCardToOopClosure { 81 private: 82 HeapRegion* _hr; 83 G1ParPushHeapRSClosure* _rs_scan; 84 G1CollectedHeap* _g1; 85 86 // Walk the given memory region from bottom to (actual) top 87 // looking for objects and applying the oop closure (_cl) to 88 // them. The base implementation of this treats the area as 89 // blocks, where a block may or may not be an object. Sub- 90 // classes should override this to provide more accurate 91 // or possibly more efficient walking. 92 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top); 93 94 public: 95 HeapRegionDCTOC(G1CollectedHeap* g1, 96 HeapRegion* hr, 97 G1ParPushHeapRSClosure* cl, 98 CardTableModRefBS::PrecisionStyle precision); 99 }; 100 101 // The complicating factor is that BlockOffsetTable diverged 102 // significantly, and we need functionality that is only in the G1 version. 103 // So I copied that code, which led to an alternate G1 version of 104 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could 105 // be reconciled, then G1OffsetTableContigSpace could go away. 106 107 // The idea behind time stamps is the following. We want to keep track of 108 // the highest address where it's safe to scan objects for each region. 109 // This is only relevant for current GC alloc regions so we keep a time stamp 110 // per region to determine if the region has been allocated during the current 111 // GC or not. If the time stamp is current we report a scan_top value which 112 // was saved at the end of the previous GC for retained alloc regions and which is 113 // equal to the bottom for all other regions. 114 // There is a race between card scanners and allocating gc workers where we must ensure 115 // that card scanners do not read the memory allocated by the gc workers. 116 // In order to enforce that, we must not return a value of _top which is more recent than the 117 // time stamp. This is due to the fact that a region may become a gc alloc region at 118 // some point after we've read the timestamp value as being < the current time stamp. 119 // The time stamps are re-initialized to zero at cleanup and at Full GCs. 120 // The current scheme that uses sequential unsigned ints will fail only if we have 4b 121 // evacuation pauses between two cleanups, which is _highly_ unlikely. 122 class G1ContiguousSpace: public CompactibleSpace { 123 friend class VMStructs; 124 HeapWord* volatile _top; 125 HeapWord* volatile _scan_top; 126 protected: 127 G1BlockOffsetTablePart _bot_part; 128 Mutex _par_alloc_lock; 129 volatile uint _gc_time_stamp; 130 // When we need to retire an allocation region, while other threads 131 // are also concurrently trying to allocate into it, we typically 132 // allocate a dummy object at the end of the region to ensure that 133 // no more allocations can take place in it. However, sometimes we 134 // want to know where the end of the last "real" object we allocated 135 // into the region was and this is what this keeps track. 136 HeapWord* _pre_dummy_top; 137 138 public: 139 G1ContiguousSpace(G1BlockOffsetTable* bot); 140 141 void set_top(HeapWord* value) { _top = value; } 142 HeapWord* top() const { return _top; } 143 144 protected: 145 // Reset the G1ContiguousSpace. 146 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space); 147 148 HeapWord* volatile* top_addr() { return &_top; } 149 // Try to allocate at least min_word_size and up to desired_size from this Space. 150 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 151 // space allocated. 152 // This version assumes that all allocation requests to this Space are properly 153 // synchronized. 154 inline HeapWord* allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 155 // Try to allocate at least min_word_size and up to desired_size from this Space. 156 // Returns NULL if not possible, otherwise sets actual_word_size to the amount of 157 // space allocated. 158 // This version synchronizes with other calls to par_allocate_impl(). 159 inline HeapWord* par_allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 160 161 public: 162 void reset_after_compaction() { set_top(compaction_top()); } 163 164 size_t used() const { return byte_size(bottom(), top()); } 165 size_t free() const { return byte_size(top(), end()); } 166 bool is_free_block(const HeapWord* p) const { return p >= top(); } 167 168 MemRegion used_region() const { return MemRegion(bottom(), top()); } 169 170 void object_iterate(ObjectClosure* blk); 171 void safe_object_iterate(ObjectClosure* blk); 172 173 void mangle_unused_area() PRODUCT_RETURN; 174 void mangle_unused_area_complete() PRODUCT_RETURN; 175 176 HeapWord* scan_top() const; 177 void record_timestamp(); 178 void reset_gc_time_stamp() { _gc_time_stamp = 0; } 179 uint get_gc_time_stamp() { return _gc_time_stamp; } 180 void record_retained_region(); 181 182 // See the comment above in the declaration of _pre_dummy_top for an 183 // explanation of what it is. 184 void set_pre_dummy_top(HeapWord* pre_dummy_top) { 185 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition"); 186 _pre_dummy_top = pre_dummy_top; 187 } 188 HeapWord* pre_dummy_top() { 189 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top; 190 } 191 void reset_pre_dummy_top() { _pre_dummy_top = NULL; } 192 193 virtual void clear(bool mangle_space); 194 195 HeapWord* block_start(const void* p); 196 HeapWord* block_start_const(const void* p) const; 197 198 // Allocation (return NULL if full). Assumes the caller has established 199 // mutually exclusive access to the space. 200 HeapWord* allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 201 // Allocation (return NULL if full). Enforces mutual exclusion internally. 202 HeapWord* par_allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size); 203 204 virtual HeapWord* allocate(size_t word_size); 205 virtual HeapWord* par_allocate(size_t word_size); 206 207 HeapWord* saved_mark_word() const { ShouldNotReachHere(); return NULL; } 208 209 // MarkSweep support phase3 210 virtual HeapWord* initialize_threshold(); 211 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); 212 213 virtual void print() const; 214 215 void reset_bot() { 216 _bot_part.reset_bot(); 217 } 218 219 void print_bot_on(outputStream* out) { 220 _bot_part.print_on(out); 221 } 222 }; 223 224 class HeapRegion: public G1ContiguousSpace { 225 friend class VMStructs; 226 // Allow scan_and_forward to call (private) overrides for auxiliary functions on this class 227 template <typename SpaceType> 228 friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp); 229 private: 230 231 // The remembered set for this region. 232 // (Might want to make this "inline" later, to avoid some alloc failure 233 // issues.) 234 HeapRegionRemSet* _rem_set; 235 236 // Auxiliary functions for scan_and_forward support. 237 // See comments for CompactibleSpace for more information. 238 inline HeapWord* scan_limit() const { 239 return top(); 240 } 241 242 inline bool scanned_block_is_obj(const HeapWord* addr) const { 243 return true; // Always true, since scan_limit is top 244 } 245 246 inline size_t scanned_block_size(const HeapWord* addr) const { 247 return HeapRegion::block_size(addr); // Avoid virtual call 248 } 249 250 void report_region_type_change(G1HeapRegionTraceType::Type to); 251 252 // Returns whether the given object address refers to a dead address, and either the 253 // size of the object (if live) or the size of the block (if dead) in size. 254 // Performs some optimizations if is_gc_active is set. 255 template <bool is_gc_active> 256 inline bool is_obj_dead_with_size(const oop obj, G1CMBitMapRO* bitmap, size_t* size) const; 257 258 protected: 259 // The index of this region in the heap region sequence. 260 uint _hrm_index; 261 262 AllocationContext_t _allocation_context; 263 264 HeapRegionType _type; 265 266 // For a humongous region, region in which it starts. 267 HeapRegion* _humongous_start_region; 268 269 // True iff an attempt to evacuate an object in the region failed. 270 bool _evacuation_failed; 271 272 // Fields used by the HeapRegionSetBase class and subclasses. 273 HeapRegion* _next; 274 HeapRegion* _prev; 275 #ifdef ASSERT 276 HeapRegionSetBase* _containing_set; 277 #endif // ASSERT 278 279 // We use concurrent marking to determine the amount of live data 280 // in each heap region. 281 size_t _prev_marked_bytes; // Bytes known to be live via last completed marking. 282 size_t _next_marked_bytes; // Bytes known to be live via in-progress marking. 283 284 // The calculated GC efficiency of the region. 285 double _gc_efficiency; 286 287 int _young_index_in_cset; 288 SurvRateGroup* _surv_rate_group; 289 int _age_index; 290 291 // The start of the unmarked area. The unmarked area extends from this 292 // word until the top and/or end of the region, and is the part 293 // of the region for which no marking was done, i.e. objects may 294 // have been allocated in this part since the last mark phase. 295 // "prev" is the top at the start of the last completed marking. 296 // "next" is the top at the start of the in-progress marking (if any.) 297 HeapWord* _prev_top_at_mark_start; 298 HeapWord* _next_top_at_mark_start; 299 // If a collection pause is in progress, this is the top at the start 300 // of that pause. 301 302 void init_top_at_mark_start() { 303 assert(_prev_marked_bytes == 0 && 304 _next_marked_bytes == 0, 305 "Must be called after zero_marked_bytes."); 306 HeapWord* bot = bottom(); 307 _prev_top_at_mark_start = bot; 308 _next_top_at_mark_start = bot; 309 } 310 311 // Cached attributes used in the collection set policy information 312 313 // The RSet length that was added to the total value 314 // for the collection set. 315 size_t _recorded_rs_length; 316 317 // The predicted elapsed time that was added to total value 318 // for the collection set. 319 double _predicted_elapsed_time_ms; 320 321 // Returns the object size for all valid block starts. Must only be called for 322 // blocks with an address < top(). 323 size_t block_size_during_gc(const HeapWord* p, const G1CMBitMapRO* bitmap) const; 324 325 // Iterate over the references in a humongous objects and apply the given closure 326 // to them. 327 // Humongous objects are allocated directly in the old-gen. So we need special 328 // handling for concurrent processing encountering an in-progress allocation. 329 template <class Closure, bool is_gc_active> 330 inline bool do_oops_on_card_in_humongous(MemRegion mr, 331 Closure* cl, 332 G1CollectedHeap* g1h); 333 public: 334 HeapRegion(uint hrm_index, 335 G1BlockOffsetTable* bot, 336 MemRegion mr); 337 338 // Initializing the HeapRegion not only resets the data structure, but also 339 // resets the BOT for that heap region. 340 // The default values for clear_space means that we will do the clearing if 341 // there's clearing to be done ourselves. We also always mangle the space. 342 virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle); 343 344 static int LogOfHRGrainBytes; 345 static int LogOfHRGrainWords; 346 347 static size_t GrainBytes; 348 static size_t GrainWords; 349 static size_t CardsPerRegion; 350 351 static size_t align_up_to_region_byte_size(size_t sz) { 352 return (sz + (size_t) GrainBytes - 1) & 353 ~((1 << (size_t) LogOfHRGrainBytes) - 1); 354 } 355 356 357 // Returns whether a field is in the same region as the obj it points to. 358 template <typename T> 359 static bool is_in_same_region(T* p, oop obj) { 360 assert(p != NULL, "p can't be NULL"); 361 assert(obj != NULL, "obj can't be NULL"); 362 return (((uintptr_t) p ^ cast_from_oop<uintptr_t>(obj)) >> LogOfHRGrainBytes) == 0; 363 } 364 365 static size_t max_region_size(); 366 static size_t min_region_size_in_words(); 367 368 // It sets up the heap region size (GrainBytes / GrainWords), as 369 // well as other related fields that are based on the heap region 370 // size (LogOfHRGrainBytes / LogOfHRGrainWords / 371 // CardsPerRegion). All those fields are considered constant 372 // throughout the JVM's execution, therefore they should only be set 373 // up once during initialization time. 374 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 375 376 // All allocated blocks are occupied by objects in a HeapRegion 377 bool block_is_obj(const HeapWord* p) const; 378 379 // Returns the object size for all valid block starts 380 // and the amount of unallocated words if called on top() 381 size_t block_size(const HeapWord* p) const; 382 383 // Override for scan_and_forward support. 384 void prepare_for_compaction(CompactPoint* cp); 385 386 inline HeapWord* par_allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* word_size); 387 inline HeapWord* allocate_no_bot_updates(size_t word_size); 388 inline HeapWord* allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* actual_size); 389 390 // If this region is a member of a HeapRegionManager, the index in that 391 // sequence, otherwise -1. 392 uint hrm_index() const { return _hrm_index; } 393 394 // The number of bytes marked live in the region in the last marking phase. 395 size_t marked_bytes() { return _prev_marked_bytes; } 396 size_t live_bytes() { 397 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes(); 398 } 399 400 // The number of bytes counted in the next marking. 401 size_t next_marked_bytes() { return _next_marked_bytes; } 402 // The number of bytes live wrt the next marking. 403 size_t next_live_bytes() { 404 return 405 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes(); 406 } 407 408 // A lower bound on the amount of garbage bytes in the region. 409 size_t garbage_bytes() { 410 size_t used_at_mark_start_bytes = 411 (prev_top_at_mark_start() - bottom()) * HeapWordSize; 412 return used_at_mark_start_bytes - marked_bytes(); 413 } 414 415 // Return the amount of bytes we'll reclaim if we collect this 416 // region. This includes not only the known garbage bytes in the 417 // region but also any unallocated space in it, i.e., [top, end), 418 // since it will also be reclaimed if we collect the region. 419 size_t reclaimable_bytes() { 420 size_t known_live_bytes = live_bytes(); 421 assert(known_live_bytes <= capacity(), "sanity"); 422 return capacity() - known_live_bytes; 423 } 424 425 // An upper bound on the number of live bytes in the region. 426 size_t max_live_bytes() { return used() - garbage_bytes(); } 427 428 void add_to_marked_bytes(size_t incr_bytes) { 429 _next_marked_bytes = _next_marked_bytes + incr_bytes; 430 } 431 432 void zero_marked_bytes() { 433 _prev_marked_bytes = _next_marked_bytes = 0; 434 } 435 436 const char* get_type_str() const { return _type.get_str(); } 437 const char* get_short_type_str() const { return _type.get_short_str(); } 438 G1HeapRegionTraceType::Type get_trace_type() { return _type.get_trace_type(); } 439 440 bool is_free() const { return _type.is_free(); } 441 442 bool is_young() const { return _type.is_young(); } 443 bool is_eden() const { return _type.is_eden(); } 444 bool is_survivor() const { return _type.is_survivor(); } 445 446 bool is_humongous() const { return _type.is_humongous(); } 447 bool is_starts_humongous() const { return _type.is_starts_humongous(); } 448 bool is_continues_humongous() const { return _type.is_continues_humongous(); } 449 450 bool is_old() const { return _type.is_old(); } 451 452 bool is_old_or_humongous() const { return _type.is_old_or_humongous(); } 453 454 // A pinned region contains objects which are not moved by garbage collections. 455 // Humongous regions and archive regions are pinned. 456 bool is_pinned() const { return _type.is_pinned(); } 457 458 // An archive region is a pinned region, also tagged as old, which 459 // should not be marked during mark/sweep. This allows the address 460 // space to be shared by JVM instances. 461 bool is_archive() const { return _type.is_archive(); } 462 463 // For a humongous region, region in which it starts. 464 HeapRegion* humongous_start_region() const { 465 return _humongous_start_region; 466 } 467 468 // Makes the current region be a "starts humongous" region, i.e., 469 // the first region in a series of one or more contiguous regions 470 // that will contain a single "humongous" object. 471 // 472 // obj_top : points to the top of the humongous object. 473 // fill_size : size of the filler object at the end of the region series. 474 void set_starts_humongous(HeapWord* obj_top, size_t fill_size); 475 476 // Makes the current region be a "continues humongous' 477 // region. first_hr is the "start humongous" region of the series 478 // which this region will be part of. 479 void set_continues_humongous(HeapRegion* first_hr); 480 481 // Unsets the humongous-related fields on the region. 482 void clear_humongous(); 483 484 // If the region has a remembered set, return a pointer to it. 485 HeapRegionRemSet* rem_set() const { 486 return _rem_set; 487 } 488 489 inline bool in_collection_set() const; 490 491 void set_allocation_context(AllocationContext_t context) { 492 _allocation_context = context; 493 } 494 495 AllocationContext_t allocation_context() const { 496 return _allocation_context; 497 } 498 499 // Methods used by the HeapRegionSetBase class and subclasses. 500 501 // Getter and setter for the next and prev fields used to link regions into 502 // linked lists. 503 HeapRegion* next() { return _next; } 504 HeapRegion* prev() { return _prev; } 505 506 void set_next(HeapRegion* next) { _next = next; } 507 void set_prev(HeapRegion* prev) { _prev = prev; } 508 509 // Every region added to a set is tagged with a reference to that 510 // set. This is used for doing consistency checking to make sure that 511 // the contents of a set are as they should be and it's only 512 // available in non-product builds. 513 #ifdef ASSERT 514 void set_containing_set(HeapRegionSetBase* containing_set) { 515 assert((containing_set == NULL && _containing_set != NULL) || 516 (containing_set != NULL && _containing_set == NULL), 517 "containing_set: " PTR_FORMAT " " 518 "_containing_set: " PTR_FORMAT, 519 p2i(containing_set), p2i(_containing_set)); 520 521 _containing_set = containing_set; 522 } 523 524 HeapRegionSetBase* containing_set() { return _containing_set; } 525 #else // ASSERT 526 void set_containing_set(HeapRegionSetBase* containing_set) { } 527 528 // containing_set() is only used in asserts so there's no reason 529 // to provide a dummy version of it. 530 #endif // ASSERT 531 532 533 // Reset the HeapRegion to default values. 534 // If skip_remset is true, do not clear the remembered set. 535 void hr_clear(bool skip_remset, bool clear_space, bool locked = false); 536 // Clear the parts skipped by skip_remset in hr_clear() in the HeapRegion during 537 // a concurrent phase. 538 void par_clear(); 539 540 // Get the start of the unmarked area in this region. 541 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; } 542 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; } 543 544 // Note the start or end of marking. This tells the heap region 545 // that the collector is about to start or has finished (concurrently) 546 // marking the heap. 547 548 // Notify the region that concurrent marking is starting. Initialize 549 // all fields related to the next marking info. 550 inline void note_start_of_marking(); 551 552 // Notify the region that concurrent marking has finished. Copy the 553 // (now finalized) next marking info fields into the prev marking 554 // info fields. 555 inline void note_end_of_marking(); 556 557 // Notify the region that it will be used as to-space during a GC 558 // and we are about to start copying objects into it. 559 inline void note_start_of_copying(bool during_initial_mark); 560 561 // Notify the region that it ceases being to-space during a GC and 562 // we will not copy objects into it any more. 563 inline void note_end_of_copying(bool during_initial_mark); 564 565 // Notify the region that we are about to start processing 566 // self-forwarded objects during evac failure handling. 567 void note_self_forwarding_removal_start(bool during_initial_mark, 568 bool during_conc_mark); 569 570 // Notify the region that we have finished processing self-forwarded 571 // objects during evac failure handling. 572 void note_self_forwarding_removal_end(size_t marked_bytes); 573 574 // Returns "false" iff no object in the region was allocated when the 575 // last mark phase ended. 576 bool is_marked() { return _prev_top_at_mark_start != bottom(); } 577 578 void reset_during_compaction() { 579 assert(is_humongous(), 580 "should only be called for humongous regions"); 581 582 zero_marked_bytes(); 583 init_top_at_mark_start(); 584 } 585 586 void calc_gc_efficiency(void); 587 double gc_efficiency() { return _gc_efficiency;} 588 589 int young_index_in_cset() const { return _young_index_in_cset; } 590 void set_young_index_in_cset(int index) { 591 assert( (index == -1) || is_young(), "pre-condition" ); 592 _young_index_in_cset = index; 593 } 594 595 int age_in_surv_rate_group() { 596 assert( _surv_rate_group != NULL, "pre-condition" ); 597 assert( _age_index > -1, "pre-condition" ); 598 return _surv_rate_group->age_in_group(_age_index); 599 } 600 601 void record_surv_words_in_group(size_t words_survived) { 602 assert( _surv_rate_group != NULL, "pre-condition" ); 603 assert( _age_index > -1, "pre-condition" ); 604 int age_in_group = age_in_surv_rate_group(); 605 _surv_rate_group->record_surviving_words(age_in_group, words_survived); 606 } 607 608 int age_in_surv_rate_group_cond() { 609 if (_surv_rate_group != NULL) 610 return age_in_surv_rate_group(); 611 else 612 return -1; 613 } 614 615 SurvRateGroup* surv_rate_group() { 616 return _surv_rate_group; 617 } 618 619 void install_surv_rate_group(SurvRateGroup* surv_rate_group) { 620 assert( surv_rate_group != NULL, "pre-condition" ); 621 assert( _surv_rate_group == NULL, "pre-condition" ); 622 assert( is_young(), "pre-condition" ); 623 624 _surv_rate_group = surv_rate_group; 625 _age_index = surv_rate_group->next_age_index(); 626 } 627 628 void uninstall_surv_rate_group() { 629 if (_surv_rate_group != NULL) { 630 assert( _age_index > -1, "pre-condition" ); 631 assert( is_young(), "pre-condition" ); 632 633 _surv_rate_group = NULL; 634 _age_index = -1; 635 } else { 636 assert( _age_index == -1, "pre-condition" ); 637 } 638 } 639 640 void set_free(); 641 642 void set_eden(); 643 void set_eden_pre_gc(); 644 void set_survivor(); 645 646 void set_old(); 647 648 void set_archive(); 649 650 // Determine if an object has been allocated since the last 651 // mark performed by the collector. This returns true iff the object 652 // is within the unmarked area of the region. 653 bool obj_allocated_since_prev_marking(oop obj) const { 654 return (HeapWord *) obj >= prev_top_at_mark_start(); 655 } 656 bool obj_allocated_since_next_marking(oop obj) const { 657 return (HeapWord *) obj >= next_top_at_mark_start(); 658 } 659 660 // Returns the "evacuation_failed" property of the region. 661 bool evacuation_failed() { return _evacuation_failed; } 662 663 // Sets the "evacuation_failed" property of the region. 664 void set_evacuation_failed(bool b) { 665 _evacuation_failed = b; 666 667 if (b) { 668 _next_marked_bytes = 0; 669 } 670 } 671 672 // Iterate over the objects overlapping part of a card, applying cl 673 // to all references in the region. This is a helper for 674 // G1RemSet::refine_card, and is tightly coupled with it. 675 // mr: the memory region covered by the card, trimmed to the 676 // allocated space for this region. Must not be empty. 677 // This region must be old or humongous. 678 // Returns true if the designated objects were successfully 679 // processed, false if an unparsable part of the heap was 680 // encountered; that only happens when invoked concurrently with the 681 // mutator. 682 template <class Closure, bool is_gc_active> 683 inline bool oops_on_card_seq_iterate_careful(MemRegion mr, Closure* cl); 684 685 size_t recorded_rs_length() const { return _recorded_rs_length; } 686 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; } 687 688 void set_recorded_rs_length(size_t rs_length) { 689 _recorded_rs_length = rs_length; 690 } 691 692 void set_predicted_elapsed_time_ms(double ms) { 693 _predicted_elapsed_time_ms = ms; 694 } 695 696 virtual CompactibleSpace* next_compaction_space() const; 697 698 virtual void reset_after_compaction(); 699 700 // Routines for managing a list of code roots (attached to the 701 // this region's RSet) that point into this heap region. 702 void add_strong_code_root(nmethod* nm); 703 void add_strong_code_root_locked(nmethod* nm); 704 void remove_strong_code_root(nmethod* nm); 705 706 // Applies blk->do_code_blob() to each of the entries in 707 // the strong code roots list for this region 708 void strong_code_roots_do(CodeBlobClosure* blk) const; 709 710 // Verify that the entries on the strong code root list for this 711 // region are live and include at least one pointer into this region. 712 void verify_strong_code_roots(VerifyOption vo, bool* failures) const; 713 714 void print() const; 715 void print_on(outputStream* st) const; 716 717 // vo == UsePrevMarking -> use "prev" marking information, 718 // vo == UseNextMarking -> use "next" marking information 719 // vo == UseMarkWord -> use the mark word in the object header 720 // 721 // NOTE: Only the "prev" marking information is guaranteed to be 722 // consistent most of the time, so most calls to this should use 723 // vo == UsePrevMarking. 724 // Currently, there is only one case where this is called with 725 // vo == UseNextMarking, which is to verify the "next" marking 726 // information at the end of remark. 727 // Currently there is only one place where this is called with 728 // vo == UseMarkWord, which is to verify the marking during a 729 // full GC. 730 void verify(VerifyOption vo, bool *failures) const; 731 732 // Override; it uses the "prev" marking information 733 virtual void verify() const; 734 735 void verify_rem_set(VerifyOption vo, bool *failures) const; 736 void verify_rem_set() const; 737 }; 738 739 // HeapRegionClosure is used for iterating over regions. 740 // Terminates the iteration when the "doHeapRegion" method returns "true". 741 class HeapRegionClosure : public StackObj { 742 friend class HeapRegionManager; 743 friend class G1CollectionSet; 744 745 bool _complete; 746 void incomplete() { _complete = false; } 747 748 public: 749 HeapRegionClosure(): _complete(true) {} 750 751 // Typically called on each region until it returns true. 752 virtual bool doHeapRegion(HeapRegion* r) = 0; 753 754 // True after iteration if the closure was applied to all heap regions 755 // and returned "false" in all cases. 756 bool complete() { return _complete; } 757 }; 758 759 #endif // SHARE_VM_GC_G1_HEAPREGION_HPP