Wed, 25 Apr 2012 10:23:12 -0700
7143490: G1: Remove HeapRegion::_top_at_conc_mark_count
Summary: Removed the HeapRegion::_top_at_conc_mark_count field. It is no longer needed as a result of the changes for 6888336 and 7127706. Refactored the closures that finalize and verify the liveness counting data so that common functionality was placed into a base class.
Reviewed-by: brutisso, tonyp
1 /*
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25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP
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"
36 #ifndef SERIALGC
38 // A HeapRegion is the smallest piece of a G1CollectedHeap that
39 // can be collected independently.
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.
48 class CompactibleSpace;
49 class ContiguousSpace;
50 class HeapRegionRemSet;
51 class HeapRegionRemSetIterator;
52 class HeapRegion;
53 class HeapRegionSetBase;
55 #define HR_FORMAT "%u:(%s)["PTR_FORMAT","PTR_FORMAT","PTR_FORMAT"]"
56 #define HR_FORMAT_PARAMS(_hr_) \
57 (_hr_)->hrs_index(), \
58 (_hr_)->is_survivor() ? "S" : (_hr_)->is_young() ? "E" : "-", \
59 (_hr_)->bottom(), (_hr_)->top(), (_hr_)->end()
61 // sentinel value for hrs_index
62 #define G1_NULL_HRS_INDEX ((uint) -1)
64 // A dirty card to oop closure for heap regions. It
65 // knows how to get the G1 heap and how to use the bitmap
66 // in the concurrent marker used by G1 to filter remembered
67 // sets.
69 class HeapRegionDCTOC : public ContiguousSpaceDCTOC {
70 public:
71 // Specification of possible DirtyCardToOopClosure filtering.
72 enum FilterKind {
73 NoFilterKind,
74 IntoCSFilterKind,
75 OutOfRegionFilterKind
76 };
78 protected:
79 HeapRegion* _hr;
80 FilterKind _fk;
81 G1CollectedHeap* _g1;
83 void walk_mem_region_with_cl(MemRegion mr,
84 HeapWord* bottom, HeapWord* top,
85 OopClosure* cl);
87 // We don't specialize this for FilteringClosure; filtering is handled by
88 // the "FilterKind" mechanism. But we provide this to avoid a compiler
89 // warning.
90 void walk_mem_region_with_cl(MemRegion mr,
91 HeapWord* bottom, HeapWord* top,
92 FilteringClosure* cl) {
93 HeapRegionDCTOC::walk_mem_region_with_cl(mr, bottom, top,
94 (OopClosure*)cl);
95 }
97 // Get the actual top of the area on which the closure will
98 // operate, given where the top is assumed to be (the end of the
99 // memory region passed to do_MemRegion) and where the object
100 // at the top is assumed to start. For example, an object may
101 // start at the top but actually extend past the assumed top,
102 // in which case the top becomes the end of the object.
103 HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj) {
104 return ContiguousSpaceDCTOC::get_actual_top(top, top_obj);
105 }
107 // Walk the given memory region from bottom to (actual) top
108 // looking for objects and applying the oop closure (_cl) to
109 // them. The base implementation of this treats the area as
110 // blocks, where a block may or may not be an object. Sub-
111 // classes should override this to provide more accurate
112 // or possibly more efficient walking.
113 void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top) {
114 Filtering_DCTOC::walk_mem_region(mr, bottom, top);
115 }
117 public:
118 HeapRegionDCTOC(G1CollectedHeap* g1,
119 HeapRegion* hr, OopClosure* cl,
120 CardTableModRefBS::PrecisionStyle precision,
121 FilterKind fk);
122 };
124 // The complicating factor is that BlockOffsetTable diverged
125 // significantly, and we need functionality that is only in the G1 version.
126 // So I copied that code, which led to an alternate G1 version of
127 // OffsetTableContigSpace. If the two versions of BlockOffsetTable could
128 // be reconciled, then G1OffsetTableContigSpace could go away.
130 // The idea behind time stamps is the following. Doing a save_marks on
131 // all regions at every GC pause is time consuming (if I remember
132 // well, 10ms or so). So, we would like to do that only for regions
133 // that are GC alloc regions. To achieve this, we use time
134 // stamps. For every evacuation pause, G1CollectedHeap generates a
135 // unique time stamp (essentially a counter that gets
136 // incremented). Every time we want to call save_marks on a region,
137 // we set the saved_mark_word to top and also copy the current GC
138 // time stamp to the time stamp field of the space. Reading the
139 // saved_mark_word involves checking the time stamp of the
140 // region. If it is the same as the current GC time stamp, then we
141 // can safely read the saved_mark_word field, as it is valid. If the
142 // time stamp of the region is not the same as the current GC time
143 // stamp, then we instead read top, as the saved_mark_word field is
144 // invalid. Time stamps (on the regions and also on the
145 // G1CollectedHeap) are reset at every cleanup (we iterate over
146 // the regions anyway) and at the end of a Full GC. The current scheme
147 // that uses sequential unsigned ints will fail only if we have 4b
148 // evacuation pauses between two cleanups, which is _highly_ unlikely.
150 class G1OffsetTableContigSpace: public ContiguousSpace {
151 friend class VMStructs;
152 protected:
153 G1BlockOffsetArrayContigSpace _offsets;
154 Mutex _par_alloc_lock;
155 volatile unsigned _gc_time_stamp;
156 // When we need to retire an allocation region, while other threads
157 // are also concurrently trying to allocate into it, we typically
158 // allocate a dummy object at the end of the region to ensure that
159 // no more allocations can take place in it. However, sometimes we
160 // want to know where the end of the last "real" object we allocated
161 // into the region was and this is what this keeps track.
162 HeapWord* _pre_dummy_top;
164 public:
165 // Constructor. If "is_zeroed" is true, the MemRegion "mr" may be
166 // assumed to contain zeros.
167 G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray,
168 MemRegion mr, bool is_zeroed = false);
170 void set_bottom(HeapWord* value);
171 void set_end(HeapWord* value);
173 virtual HeapWord* saved_mark_word() const;
174 virtual void set_saved_mark();
175 void reset_gc_time_stamp() { _gc_time_stamp = 0; }
177 // See the comment above in the declaration of _pre_dummy_top for an
178 // explanation of what it is.
179 void set_pre_dummy_top(HeapWord* pre_dummy_top) {
180 assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition");
181 _pre_dummy_top = pre_dummy_top;
182 }
183 HeapWord* pre_dummy_top() {
184 return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top;
185 }
186 void reset_pre_dummy_top() { _pre_dummy_top = NULL; }
188 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space);
189 virtual void clear(bool mangle_space);
191 HeapWord* block_start(const void* p);
192 HeapWord* block_start_const(const void* p) const;
194 // Add offset table update.
195 virtual HeapWord* allocate(size_t word_size);
196 HeapWord* par_allocate(size_t word_size);
198 // MarkSweep support phase3
199 virtual HeapWord* initialize_threshold();
200 virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end);
202 virtual void print() const;
204 void reset_bot() {
205 _offsets.zero_bottom_entry();
206 _offsets.initialize_threshold();
207 }
209 void update_bot_for_object(HeapWord* start, size_t word_size) {
210 _offsets.alloc_block(start, word_size);
211 }
213 void print_bot_on(outputStream* out) {
214 _offsets.print_on(out);
215 }
216 };
218 class HeapRegion: public G1OffsetTableContigSpace {
219 friend class VMStructs;
220 private:
222 enum HumongousType {
223 NotHumongous = 0,
224 StartsHumongous,
225 ContinuesHumongous
226 };
228 // Requires that the region "mr" be dense with objects, and begin and end
229 // with an object.
230 void oops_in_mr_iterate(MemRegion mr, OopClosure* cl);
232 // The remembered set for this region.
233 // (Might want to make this "inline" later, to avoid some alloc failure
234 // issues.)
235 HeapRegionRemSet* _rem_set;
237 G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; }
239 protected:
240 // The index of this region in the heap region sequence.
241 uint _hrs_index;
243 HumongousType _humongous_type;
244 // For a humongous region, region in which it starts.
245 HeapRegion* _humongous_start_region;
246 // For the start region of a humongous sequence, it's original end().
247 HeapWord* _orig_end;
249 // True iff the region is in current collection_set.
250 bool _in_collection_set;
252 // True iff an attempt to evacuate an object in the region failed.
253 bool _evacuation_failed;
255 // A heap region may be a member one of a number of special subsets, each
256 // represented as linked lists through the field below. Currently, these
257 // sets include:
258 // The collection set.
259 // The set of allocation regions used in a collection pause.
260 // Spaces that may contain gray objects.
261 HeapRegion* _next_in_special_set;
263 // next region in the young "generation" region set
264 HeapRegion* _next_young_region;
266 // Next region whose cards need cleaning
267 HeapRegion* _next_dirty_cards_region;
269 // Fields used by the HeapRegionSetBase class and subclasses.
270 HeapRegion* _next;
271 #ifdef ASSERT
272 HeapRegionSetBase* _containing_set;
273 #endif // ASSERT
274 bool _pending_removal;
276 // For parallel heapRegion traversal.
277 jint _claimed;
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.
284 // The calculated GC efficiency of the region.
285 double _gc_efficiency;
287 enum YoungType {
288 NotYoung, // a region is not young
289 Young, // a region is young
290 Survivor // a region is young and it contains survivors
291 };
293 volatile YoungType _young_type;
294 int _young_index_in_cset;
295 SurvRateGroup* _surv_rate_group;
296 int _age_index;
298 // The start of the unmarked area. The unmarked area extends from this
299 // word until the top and/or end of the region, and is the part
300 // of the region for which no marking was done, i.e. objects may
301 // have been allocated in this part since the last mark phase.
302 // "prev" is the top at the start of the last completed marking.
303 // "next" is the top at the start of the in-progress marking (if any.)
304 HeapWord* _prev_top_at_mark_start;
305 HeapWord* _next_top_at_mark_start;
306 // If a collection pause is in progress, this is the top at the start
307 // of that pause.
309 void init_top_at_mark_start() {
310 assert(_prev_marked_bytes == 0 &&
311 _next_marked_bytes == 0,
312 "Must be called after zero_marked_bytes.");
313 HeapWord* bot = bottom();
314 _prev_top_at_mark_start = bot;
315 _next_top_at_mark_start = bot;
316 }
318 void set_young_type(YoungType new_type) {
319 //assert(_young_type != new_type, "setting the same type" );
320 // TODO: add more assertions here
321 _young_type = new_type;
322 }
324 // Cached attributes used in the collection set policy information
326 // The RSet length that was added to the total value
327 // for the collection set.
328 size_t _recorded_rs_length;
330 // The predicted elapsed time that was added to total value
331 // for the collection set.
332 double _predicted_elapsed_time_ms;
334 // The predicted number of bytes to copy that was added to
335 // the total value for the collection set.
336 size_t _predicted_bytes_to_copy;
338 public:
339 // If "is_zeroed" is "true", the region "mr" can be assumed to contain zeros.
340 HeapRegion(uint hrs_index,
341 G1BlockOffsetSharedArray* sharedOffsetArray,
342 MemRegion mr, bool is_zeroed);
344 static int LogOfHRGrainBytes;
345 static int LogOfHRGrainWords;
347 static size_t GrainBytes;
348 static size_t GrainWords;
349 static size_t CardsPerRegion;
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 }
356 // It sets up the heap region size (GrainBytes / GrainWords), as
357 // well as other related fields that are based on the heap region
358 // size (LogOfHRGrainBytes / LogOfHRGrainWords /
359 // CardsPerRegion). All those fields are considered constant
360 // throughout the JVM's execution, therefore they should only be set
361 // up once during initialization time.
362 static void setup_heap_region_size(uintx min_heap_size);
364 enum ClaimValues {
365 InitialClaimValue = 0,
366 FinalCountClaimValue = 1,
367 NoteEndClaimValue = 2,
368 ScrubRemSetClaimValue = 3,
369 ParVerifyClaimValue = 4,
370 RebuildRSClaimValue = 5,
371 ParEvacFailureClaimValue = 6,
372 AggregateCountClaimValue = 7,
373 VerifyCountClaimValue = 8
374 };
376 inline HeapWord* par_allocate_no_bot_updates(size_t word_size) {
377 assert(is_young(), "we can only skip BOT updates on young regions");
378 return ContiguousSpace::par_allocate(word_size);
379 }
380 inline HeapWord* allocate_no_bot_updates(size_t word_size) {
381 assert(is_young(), "we can only skip BOT updates on young regions");
382 return ContiguousSpace::allocate(word_size);
383 }
385 // If this region is a member of a HeapRegionSeq, the index in that
386 // sequence, otherwise -1.
387 uint hrs_index() const { return _hrs_index; }
389 // The number of bytes marked live in the region in the last marking phase.
390 size_t marked_bytes() { return _prev_marked_bytes; }
391 size_t live_bytes() {
392 return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes();
393 }
395 // The number of bytes counted in the next marking.
396 size_t next_marked_bytes() { return _next_marked_bytes; }
397 // The number of bytes live wrt the next marking.
398 size_t next_live_bytes() {
399 return
400 (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes();
401 }
403 // A lower bound on the amount of garbage bytes in the region.
404 size_t garbage_bytes() {
405 size_t used_at_mark_start_bytes =
406 (prev_top_at_mark_start() - bottom()) * HeapWordSize;
407 assert(used_at_mark_start_bytes >= marked_bytes(),
408 "Can't mark more than we have.");
409 return used_at_mark_start_bytes - marked_bytes();
410 }
412 // Return the amount of bytes we'll reclaim if we collect this
413 // region. This includes not only the known garbage bytes in the
414 // region but also any unallocated space in it, i.e., [top, end),
415 // since it will also be reclaimed if we collect the region.
416 size_t reclaimable_bytes() {
417 size_t known_live_bytes = live_bytes();
418 assert(known_live_bytes <= capacity(), "sanity");
419 return capacity() - known_live_bytes;
420 }
422 // An upper bound on the number of live bytes in the region.
423 size_t max_live_bytes() { return used() - garbage_bytes(); }
425 void add_to_marked_bytes(size_t incr_bytes) {
426 _next_marked_bytes = _next_marked_bytes + incr_bytes;
427 assert(_next_marked_bytes <= used(), "invariant" );
428 }
430 void zero_marked_bytes() {
431 _prev_marked_bytes = _next_marked_bytes = 0;
432 }
434 bool isHumongous() const { return _humongous_type != NotHumongous; }
435 bool startsHumongous() const { return _humongous_type == StartsHumongous; }
436 bool continuesHumongous() const { return _humongous_type == ContinuesHumongous; }
437 // For a humongous region, region in which it starts.
438 HeapRegion* humongous_start_region() const {
439 return _humongous_start_region;
440 }
442 // Same as Space::is_in_reserved, but will use the original size of the region.
443 // The original size is different only for start humongous regions. They get
444 // their _end set up to be the end of the last continues region of the
445 // corresponding humongous object.
446 bool is_in_reserved_raw(const void* p) const {
447 return _bottom <= p && p < _orig_end;
448 }
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. The two parameters
453 // are as follows:
454 //
455 // new_top : The new value of the top field of this region which
456 // points to the end of the humongous object that's being
457 // allocated. If there is more than one region in the series, top
458 // will lie beyond this region's original end field and on the last
459 // region in the series.
460 //
461 // new_end : The new value of the end field of this region which
462 // points to the end of the last region in the series. If there is
463 // one region in the series (namely: this one) end will be the same
464 // as the original end of this region.
465 //
466 // Updating top and end as described above makes this region look as
467 // if it spans the entire space taken up by all the regions in the
468 // series and an single allocation moved its top to new_top. This
469 // ensures that the space (capacity / allocated) taken up by all
470 // humongous regions can be calculated by just looking at the
471 // "starts humongous" regions and by ignoring the "continues
472 // humongous" regions.
473 void set_startsHumongous(HeapWord* new_top, HeapWord* new_end);
475 // Makes the current region be a "continues humongous'
476 // region. first_hr is the "start humongous" region of the series
477 // which this region will be part of.
478 void set_continuesHumongous(HeapRegion* first_hr);
480 // Unsets the humongous-related fields on the region.
481 void set_notHumongous();
483 // If the region has a remembered set, return a pointer to it.
484 HeapRegionRemSet* rem_set() const {
485 return _rem_set;
486 }
488 // True iff the region is in current collection_set.
489 bool in_collection_set() const {
490 return _in_collection_set;
491 }
492 void set_in_collection_set(bool b) {
493 _in_collection_set = b;
494 }
495 HeapRegion* next_in_collection_set() {
496 assert(in_collection_set(), "should only invoke on member of CS.");
497 assert(_next_in_special_set == NULL ||
498 _next_in_special_set->in_collection_set(),
499 "Malformed CS.");
500 return _next_in_special_set;
501 }
502 void set_next_in_collection_set(HeapRegion* r) {
503 assert(in_collection_set(), "should only invoke on member of CS.");
504 assert(r == NULL || r->in_collection_set(), "Malformed CS.");
505 _next_in_special_set = r;
506 }
508 // Methods used by the HeapRegionSetBase class and subclasses.
510 // Getter and setter for the next field used to link regions into
511 // linked lists.
512 HeapRegion* next() { return _next; }
514 void set_next(HeapRegion* next) { _next = next; }
516 // Every region added to a set is tagged with a reference to that
517 // set. This is used for doing consistency checking to make sure that
518 // the contents of a set are as they should be and it's only
519 // available in non-product builds.
520 #ifdef ASSERT
521 void set_containing_set(HeapRegionSetBase* containing_set) {
522 assert((containing_set == NULL && _containing_set != NULL) ||
523 (containing_set != NULL && _containing_set == NULL),
524 err_msg("containing_set: "PTR_FORMAT" "
525 "_containing_set: "PTR_FORMAT,
526 containing_set, _containing_set));
528 _containing_set = containing_set;
529 }
531 HeapRegionSetBase* containing_set() { return _containing_set; }
532 #else // ASSERT
533 void set_containing_set(HeapRegionSetBase* containing_set) { }
535 // containing_set() is only used in asserts so there's no reason
536 // to provide a dummy version of it.
537 #endif // ASSERT
539 // If we want to remove regions from a list in bulk we can simply tag
540 // them with the pending_removal tag and call the
541 // remove_all_pending() method on the list.
543 bool pending_removal() { return _pending_removal; }
545 void set_pending_removal(bool pending_removal) {
546 if (pending_removal) {
547 assert(!_pending_removal && containing_set() != NULL,
548 "can only set pending removal to true if it's false and "
549 "the region belongs to a region set");
550 } else {
551 assert( _pending_removal && containing_set() == NULL,
552 "can only set pending removal to false if it's true and "
553 "the region does not belong to a region set");
554 }
556 _pending_removal = pending_removal;
557 }
559 HeapRegion* get_next_young_region() { return _next_young_region; }
560 void set_next_young_region(HeapRegion* hr) {
561 _next_young_region = hr;
562 }
564 HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; }
565 HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; }
566 void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; }
567 bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; }
569 HeapWord* orig_end() { return _orig_end; }
571 // Allows logical separation between objects allocated before and after.
572 void save_marks();
574 // Reset HR stuff to default values.
575 void hr_clear(bool par, bool clear_space);
576 void par_clear();
578 void initialize(MemRegion mr, bool clear_space, bool mangle_space);
580 // Get the start of the unmarked area in this region.
581 HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; }
582 HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; }
584 // Apply "cl->do_oop" to (the addresses of) all reference fields in objects
585 // allocated in the current region before the last call to "save_mark".
586 void oop_before_save_marks_iterate(OopClosure* cl);
588 // Note the start or end of marking. This tells the heap region
589 // that the collector is about to start or has finished (concurrently)
590 // marking the heap.
592 // Notify the region that concurrent marking is starting. Initialize
593 // all fields related to the next marking info.
594 inline void note_start_of_marking();
596 // Notify the region that concurrent marking has finished. Copy the
597 // (now finalized) next marking info fields into the prev marking
598 // info fields.
599 inline void note_end_of_marking();
601 // Notify the region that it will be used as to-space during a GC
602 // and we are about to start copying objects into it.
603 inline void note_start_of_copying(bool during_initial_mark);
605 // Notify the region that it ceases being to-space during a GC and
606 // we will not copy objects into it any more.
607 inline void note_end_of_copying(bool during_initial_mark);
609 // Notify the region that we are about to start processing
610 // self-forwarded objects during evac failure handling.
611 void note_self_forwarding_removal_start(bool during_initial_mark,
612 bool during_conc_mark);
614 // Notify the region that we have finished processing self-forwarded
615 // objects during evac failure handling.
616 void note_self_forwarding_removal_end(bool during_initial_mark,
617 bool during_conc_mark,
618 size_t marked_bytes);
620 // Returns "false" iff no object in the region was allocated when the
621 // last mark phase ended.
622 bool is_marked() { return _prev_top_at_mark_start != bottom(); }
624 void reset_during_compaction() {
625 guarantee( isHumongous() && startsHumongous(),
626 "should only be called for humongous regions");
628 zero_marked_bytes();
629 init_top_at_mark_start();
630 }
632 void calc_gc_efficiency(void);
633 double gc_efficiency() { return _gc_efficiency;}
635 bool is_young() const { return _young_type != NotYoung; }
636 bool is_survivor() const { return _young_type == Survivor; }
638 int young_index_in_cset() const { return _young_index_in_cset; }
639 void set_young_index_in_cset(int index) {
640 assert( (index == -1) || is_young(), "pre-condition" );
641 _young_index_in_cset = index;
642 }
644 int age_in_surv_rate_group() {
645 assert( _surv_rate_group != NULL, "pre-condition" );
646 assert( _age_index > -1, "pre-condition" );
647 return _surv_rate_group->age_in_group(_age_index);
648 }
650 void record_surv_words_in_group(size_t words_survived) {
651 assert( _surv_rate_group != NULL, "pre-condition" );
652 assert( _age_index > -1, "pre-condition" );
653 int age_in_group = age_in_surv_rate_group();
654 _surv_rate_group->record_surviving_words(age_in_group, words_survived);
655 }
657 int age_in_surv_rate_group_cond() {
658 if (_surv_rate_group != NULL)
659 return age_in_surv_rate_group();
660 else
661 return -1;
662 }
664 SurvRateGroup* surv_rate_group() {
665 return _surv_rate_group;
666 }
668 void install_surv_rate_group(SurvRateGroup* surv_rate_group) {
669 assert( surv_rate_group != NULL, "pre-condition" );
670 assert( _surv_rate_group == NULL, "pre-condition" );
671 assert( is_young(), "pre-condition" );
673 _surv_rate_group = surv_rate_group;
674 _age_index = surv_rate_group->next_age_index();
675 }
677 void uninstall_surv_rate_group() {
678 if (_surv_rate_group != NULL) {
679 assert( _age_index > -1, "pre-condition" );
680 assert( is_young(), "pre-condition" );
682 _surv_rate_group = NULL;
683 _age_index = -1;
684 } else {
685 assert( _age_index == -1, "pre-condition" );
686 }
687 }
689 void set_young() { set_young_type(Young); }
691 void set_survivor() { set_young_type(Survivor); }
693 void set_not_young() { set_young_type(NotYoung); }
695 // Determine if an object has been allocated since the last
696 // mark performed by the collector. This returns true iff the object
697 // is within the unmarked area of the region.
698 bool obj_allocated_since_prev_marking(oop obj) const {
699 return (HeapWord *) obj >= prev_top_at_mark_start();
700 }
701 bool obj_allocated_since_next_marking(oop obj) const {
702 return (HeapWord *) obj >= next_top_at_mark_start();
703 }
705 // For parallel heapRegion traversal.
706 bool claimHeapRegion(int claimValue);
707 jint claim_value() { return _claimed; }
708 // Use this carefully: only when you're sure no one is claiming...
709 void set_claim_value(int claimValue) { _claimed = claimValue; }
711 // Returns the "evacuation_failed" property of the region.
712 bool evacuation_failed() { return _evacuation_failed; }
714 // Sets the "evacuation_failed" property of the region.
715 void set_evacuation_failed(bool b) {
716 _evacuation_failed = b;
718 if (b) {
719 _next_marked_bytes = 0;
720 }
721 }
723 // Requires that "mr" be entirely within the region.
724 // Apply "cl->do_object" to all objects that intersect with "mr".
725 // If the iteration encounters an unparseable portion of the region,
726 // or if "cl->abort()" is true after a closure application,
727 // terminate the iteration and return the address of the start of the
728 // subregion that isn't done. (The two can be distinguished by querying
729 // "cl->abort()".) Return of "NULL" indicates that the iteration
730 // completed.
731 HeapWord*
732 object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl);
734 // filter_young: if true and the region is a young region then we
735 // skip the iteration.
736 // card_ptr: if not NULL, and we decide that the card is not young
737 // and we iterate over it, we'll clean the card before we start the
738 // iteration.
739 HeapWord*
740 oops_on_card_seq_iterate_careful(MemRegion mr,
741 FilterOutOfRegionClosure* cl,
742 bool filter_young,
743 jbyte* card_ptr);
745 // A version of block start that is guaranteed to find *some* block
746 // boundary at or before "p", but does not object iteration, and may
747 // therefore be used safely when the heap is unparseable.
748 HeapWord* block_start_careful(const void* p) const {
749 return _offsets.block_start_careful(p);
750 }
752 // Requires that "addr" is within the region. Returns the start of the
753 // first ("careful") block that starts at or after "addr", or else the
754 // "end" of the region if there is no such block.
755 HeapWord* next_block_start_careful(HeapWord* addr);
757 size_t recorded_rs_length() const { return _recorded_rs_length; }
758 double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; }
759 size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; }
761 void set_recorded_rs_length(size_t rs_length) {
762 _recorded_rs_length = rs_length;
763 }
765 void set_predicted_elapsed_time_ms(double ms) {
766 _predicted_elapsed_time_ms = ms;
767 }
769 void set_predicted_bytes_to_copy(size_t bytes) {
770 _predicted_bytes_to_copy = bytes;
771 }
773 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \
774 virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
775 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DECL)
777 CompactibleSpace* next_compaction_space() const;
779 virtual void reset_after_compaction();
781 void print() const;
782 void print_on(outputStream* st) const;
784 // vo == UsePrevMarking -> use "prev" marking information,
785 // vo == UseNextMarking -> use "next" marking information
786 // vo == UseMarkWord -> use the mark word in the object header
787 //
788 // NOTE: Only the "prev" marking information is guaranteed to be
789 // consistent most of the time, so most calls to this should use
790 // vo == UsePrevMarking.
791 // Currently, there is only one case where this is called with
792 // vo == UseNextMarking, which is to verify the "next" marking
793 // information at the end of remark.
794 // Currently there is only one place where this is called with
795 // vo == UseMarkWord, which is to verify the marking during a
796 // full GC.
797 void verify(VerifyOption vo, bool *failures) const;
799 // Override; it uses the "prev" marking information
800 virtual void verify() const;
801 };
803 // HeapRegionClosure is used for iterating over regions.
804 // Terminates the iteration when the "doHeapRegion" method returns "true".
805 class HeapRegionClosure : public StackObj {
806 friend class HeapRegionSeq;
807 friend class G1CollectedHeap;
809 bool _complete;
810 void incomplete() { _complete = false; }
812 public:
813 HeapRegionClosure(): _complete(true) {}
815 // Typically called on each region until it returns true.
816 virtual bool doHeapRegion(HeapRegion* r) = 0;
818 // True after iteration if the closure was applied to all heap regions
819 // and returned "false" in all cases.
820 bool complete() { return _complete; }
821 };
823 #endif // SERIALGC
825 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP