#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP

#define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP

#include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp"

#include "gc_implementation/g1/g1_specialized_oop_closures.hpp"

#include "gc_implementation/g1/survRateGroup.hpp"

#include "gc_implementation/shared/ageTable.hpp"

#include "gc_implementation/shared/spaceDecorator.hpp"

#include "memory/space.inline.hpp"

#include "memory/watermark.hpp"

#ifndef SERIALGC

class CompactibleSpace;

class ContiguousSpace;

class HeapRegionRemSet;

class HeapRegionRemSetIterator;

class HeapRegion;

class HeapRegionSetBase;

#define HR_FORMAT "%u:(%s)["PTR_FORMAT","PTR_FORMAT","PTR_FORMAT"]"

#define HR_FORMAT_PARAMS(_hr_) \

(_hr_)->hrs_index(), \

(_hr_)->is_survivor() ? "S" : (_hr_)->is_young() ? "E" : \

(_hr_)->startsHumongous() ? "HS" : \

(_hr_)->continuesHumongous() ? "HC" : \

!(_hr_)->is_empty() ? "O" : "F", \

(_hr_)->bottom(), (_hr_)->top(), (_hr_)->end()

#define G1_NULL_HRS_INDEX ((uint) -1)

class HeapRegionDCTOC : public ContiguousSpaceDCTOC {

public:

// Specification of possible DirtyCardToOopClosure filtering.

enum FilterKind {

NoFilterKind,

IntoCSFilterKind,

OutOfRegionFilterKind

};

protected:

HeapRegion* _hr;

FilterKind _fk;

G1CollectedHeap* _g1;

void walk_mem_region_with_cl(MemRegion mr,

HeapWord* bottom, HeapWord* top,

OopClosure* cl);

// We don't specialize this for FilteringClosure; filtering is handled by

// the "FilterKind" mechanism. But we provide this to avoid a compiler

// warning.

void walk_mem_region_with_cl(MemRegion mr,

HeapWord* bottom, HeapWord* top,

FilteringClosure* cl) {

HeapRegionDCTOC::walk_mem_region_with_cl(mr, bottom, top,

(OopClosure*)cl);

}

// Get the actual top of the area on which the closure will

// operate, given where the top is assumed to be (the end of the

// memory region passed to do_MemRegion) and where the object

// at the top is assumed to start. For example, an object may

// start at the top but actually extend past the assumed top,

// in which case the top becomes the end of the object.

HeapWord* get_actual_top(HeapWord* top, HeapWord* top_obj) {

return ContiguousSpaceDCTOC::get_actual_top(top, top_obj);

}

// Walk the given memory region from bottom to (actual) top

// looking for objects and applying the oop closure (_cl) to

// them. The base implementation of this treats the area as

// blocks, where a block may or may not be an object. Sub-

// classes should override this to provide more accurate

// or possibly more efficient walking.

void walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top) {

Filtering_DCTOC::walk_mem_region(mr, bottom, top);

}

public:

HeapRegionDCTOC(G1CollectedHeap* g1,

HeapRegion* hr, OopClosure* cl,

CardTableModRefBS::PrecisionStyle precision,

FilterKind fk);

};

class G1OffsetTableContigSpace: public ContiguousSpace {

friend class VMStructs;

protected:

G1BlockOffsetArrayContigSpace _offsets;

Mutex _par_alloc_lock;

volatile unsigned _gc_time_stamp;

// When we need to retire an allocation region, while other threads

// are also concurrently trying to allocate into it, we typically

// allocate a dummy object at the end of the region to ensure that

// no more allocations can take place in it. However, sometimes we

// want to know where the end of the last "real" object we allocated

// into the region was and this is what this keeps track.

HeapWord* _pre_dummy_top;

public:

// Constructor. If "is_zeroed" is true, the MemRegion "mr" may be

// assumed to contain zeros.

G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray,

MemRegion mr, bool is_zeroed = false);

void set_bottom(HeapWord* value);

void set_end(HeapWord* value);

virtual HeapWord* saved_mark_word() const;

virtual void set_saved_mark();

void reset_gc_time_stamp() { _gc_time_stamp = 0; }

unsigned get_gc_time_stamp() { return _gc_time_stamp; }

// See the comment above in the declaration of _pre_dummy_top for an

// explanation of what it is.

void set_pre_dummy_top(HeapWord* pre_dummy_top) {

assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition");

_pre_dummy_top = pre_dummy_top;

}

HeapWord* pre_dummy_top() {

return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top;

}

void reset_pre_dummy_top() { _pre_dummy_top = NULL; }

virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space);

virtual void clear(bool mangle_space);

HeapWord* block_start(const void* p);

HeapWord* block_start_const(const void* p) const;

// Add offset table update.

virtual HeapWord* allocate(size_t word_size);

HeapWord* par_allocate(size_t word_size);

// MarkSweep support phase3

virtual HeapWord* initialize_threshold();

virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end);

virtual void print() const;

void reset_bot() {

_offsets.zero_bottom_entry();

_offsets.initialize_threshold();

}

void update_bot_for_object(HeapWord* start, size_t word_size) {

_offsets.alloc_block(start, word_size);

}

void print_bot_on(outputStream* out) {

_offsets.print_on(out);

}

};

class HeapRegion: public G1OffsetTableContigSpace {

friend class VMStructs;

private:

enum HumongousType {

NotHumongous = 0,

StartsHumongous,

ContinuesHumongous

};

// Requires that the region "mr" be dense with objects, and begin and end

// with an object.

void oops_in_mr_iterate(MemRegion mr, OopClosure* cl);

// The remembered set for this region.

// (Might want to make this "inline" later, to avoid some alloc failure

// issues.)

HeapRegionRemSet* _rem_set;

G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; }

protected:

// The index of this region in the heap region sequence.

uint _hrs_index;

HumongousType _humongous_type;

// For a humongous region, region in which it starts.

HeapRegion* _humongous_start_region;

// For the start region of a humongous sequence, it's original end().

HeapWord* _orig_end;

// True iff the region is in current collection_set.

bool _in_collection_set;

// True iff an attempt to evacuate an object in the region failed.

bool _evacuation_failed;

// A heap region may be a member one of a number of special subsets, each

// represented as linked lists through the field below. Currently, these

// sets include:

// The collection set.

// The set of allocation regions used in a collection pause.

// Spaces that may contain gray objects.

HeapRegion* _next_in_special_set;

// next region in the young "generation" region set

HeapRegion* _next_young_region;

// Next region whose cards need cleaning

HeapRegion* _next_dirty_cards_region;

// Fields used by the HeapRegionSetBase class and subclasses.

HeapRegion* _next;

#ifdef ASSERT

HeapRegionSetBase* _containing_set;

#endif // ASSERT

bool _pending_removal;

// For parallel heapRegion traversal.

jint _claimed;

// We use concurrent marking to determine the amount of live data

// in each heap region.

size_t _prev_marked_bytes; // Bytes known to be live via last completed marking.

size_t _next_marked_bytes; // Bytes known to be live via in-progress marking.

// The calculated GC efficiency of the region.

double _gc_efficiency;

enum YoungType {

NotYoung, // a region is not young

Young, // a region is young

Survivor // a region is young and it contains survivors

};

volatile YoungType _young_type;

int _young_index_in_cset;

SurvRateGroup* _surv_rate_group;

int _age_index;

// The start of the unmarked area. The unmarked area extends from this

// word until the top and/or end of the region, and is the part

// of the region for which no marking was done, i.e. objects may

// have been allocated in this part since the last mark phase.

// "prev" is the top at the start of the last completed marking.

// "next" is the top at the start of the in-progress marking (if any.)

HeapWord* _prev_top_at_mark_start;

HeapWord* _next_top_at_mark_start;

// If a collection pause is in progress, this is the top at the start

// of that pause.

void init_top_at_mark_start() {

assert(_prev_marked_bytes == 0 &&

_next_marked_bytes == 0,

"Must be called after zero_marked_bytes.");

HeapWord* bot = bottom();

_prev_top_at_mark_start = bot;

_next_top_at_mark_start = bot;

}

void set_young_type(YoungType new_type) {

//assert(_young_type != new_type, "setting the same type" );

// TODO: add more assertions here

_young_type = new_type;

}

// Cached attributes used in the collection set policy information

// The RSet length that was added to the total value

// for the collection set.

size_t _recorded_rs_length;

// The predicted elapsed time that was added to total value

// for the collection set.

double _predicted_elapsed_time_ms;

// The predicted number of bytes to copy that was added to

// the total value for the collection set.

size_t _predicted_bytes_to_copy;

public:

// If "is_zeroed" is "true", the region "mr" can be assumed to contain zeros.

HeapRegion(uint hrs_index,

G1BlockOffsetSharedArray* sharedOffsetArray,

MemRegion mr, bool is_zeroed);

static int LogOfHRGrainBytes;

static int LogOfHRGrainWords;

static size_t GrainBytes;

static size_t GrainWords;

static size_t CardsPerRegion;

static size_t align_up_to_region_byte_size(size_t sz) {

return (sz + (size_t) GrainBytes - 1) &

~((1 << (size_t) LogOfHRGrainBytes) - 1);

}

// It sets up the heap region size (GrainBytes / GrainWords), as

// well as other related fields that are based on the heap region

// size (LogOfHRGrainBytes / LogOfHRGrainWords /

// CardsPerRegion). All those fields are considered constant

// throughout the JVM's execution, therefore they should only be set

// up once during initialization time.

static void setup_heap_region_size(uintx min_heap_size);

enum ClaimValues {

InitialClaimValue = 0,

FinalCountClaimValue = 1,

NoteEndClaimValue = 2,

ScrubRemSetClaimValue = 3,

ParVerifyClaimValue = 4,

RebuildRSClaimValue = 5,

ParEvacFailureClaimValue = 6,

AggregateCountClaimValue = 7,

VerifyCountClaimValue = 8

};

inline HeapWord* par_allocate_no_bot_updates(size_t word_size) {

assert(is_young(), "we can only skip BOT updates on young regions");

return ContiguousSpace::par_allocate(word_size);

}

inline HeapWord* allocate_no_bot_updates(size_t word_size) {

assert(is_young(), "we can only skip BOT updates on young regions");

return ContiguousSpace::allocate(word_size);

}

// If this region is a member of a HeapRegionSeq, the index in that

// sequence, otherwise -1.

uint hrs_index() const { return _hrs_index; }

// The number of bytes marked live in the region in the last marking phase.

size_t marked_bytes() { return _prev_marked_bytes; }

size_t live_bytes() {

return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes();

}

// The number of bytes counted in the next marking.

size_t next_marked_bytes() { return _next_marked_bytes; }

// The number of bytes live wrt the next marking.

size_t next_live_bytes() {

return

(top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes();

}

// A lower bound on the amount of garbage bytes in the region.

size_t garbage_bytes() {

size_t used_at_mark_start_bytes =

(prev_top_at_mark_start() - bottom()) * HeapWordSize;

assert(used_at_mark_start_bytes >= marked_bytes(),

"Can't mark more than we have.");

return used_at_mark_start_bytes - marked_bytes();

}

// Return the amount of bytes we'll reclaim if we collect this

// region. This includes not only the known garbage bytes in the

// region but also any unallocated space in it, i.e., [top, end),

// since it will also be reclaimed if we collect the region.

size_t reclaimable_bytes() {

size_t known_live_bytes = live_bytes();

assert(known_live_bytes <= capacity(), "sanity");

return capacity() - known_live_bytes;

}

// An upper bound on the number of live bytes in the region.

size_t max_live_bytes() { return used() - garbage_bytes(); }

void add_to_marked_bytes(size_t incr_bytes) {

_next_marked_bytes = _next_marked_bytes + incr_bytes;

assert(_next_marked_bytes <= used(), "invariant" );

}

void zero_marked_bytes() {

_prev_marked_bytes = _next_marked_bytes = 0;

}

bool isHumongous() const { return _humongous_type != NotHumongous; }

bool startsHumongous() const { return _humongous_type == StartsHumongous; }

bool continuesHumongous() const { return _humongous_type == ContinuesHumongous; }

// For a humongous region, region in which it starts.

HeapRegion* humongous_start_region() const {

return _humongous_start_region;

}

// Return the number of distinct regions that are covered by this region:

// 1 if the region is not humongous, >= 1 if the region is humongous.

uint region_num() const {

if (!isHumongous()) {

return 1U;

} else {

assert(startsHumongous(), "doesn't make sense on HC regions");

assert(capacity() % HeapRegion::GrainBytes == 0, "sanity");

return (uint) (capacity() >> HeapRegion::LogOfHRGrainBytes);

}

}

// Return the index + 1 of the last HC regions that's associated

// with this HS region.

uint last_hc_index() const {

assert(startsHumongous(), "don't call this otherwise");

return hrs_index() + region_num();

}

// Same as Space::is_in_reserved, but will use the original size of the region.

// The original size is different only for start humongous regions. They get

// their _end set up to be the end of the last continues region of the

// corresponding humongous object.

bool is_in_reserved_raw(const void* p) const {

return _bottom <= p && p < _orig_end;

}

// Makes the current region be a "starts humongous" region, i.e.,

// the first region in a series of one or more contiguous regions

// that will contain a single "humongous" object. The two parameters

// are as follows:

//

// new_top : The new value of the top field of this region which

// points to the end of the humongous object that's being

// allocated. If there is more than one region in the series, top

// will lie beyond this region's original end field and on the last

// region in the series.

//

// new_end : The new value of the end field of this region which

// points to the end of the last region in the series. If there is

// one region in the series (namely: this one) end will be the same

// as the original end of this region.

//

// Updating top and end as described above makes this region look as

// if it spans the entire space taken up by all the regions in the

// series and an single allocation moved its top to new_top. This

// ensures that the space (capacity / allocated) taken up by all

// humongous regions can be calculated by just looking at the

// "starts humongous" regions and by ignoring the "continues

// humongous" regions.

void set_startsHumongous(HeapWord* new_top, HeapWord* new_end);

// Makes the current region be a "continues humongous'

// region. first_hr is the "start humongous" region of the series

// which this region will be part of.

void set_continuesHumongous(HeapRegion* first_hr);

// Unsets the humongous-related fields on the region.

void set_notHumongous();

// If the region has a remembered set, return a pointer to it.

HeapRegionRemSet* rem_set() const {

return _rem_set;

}

// True iff the region is in current collection_set.

bool in_collection_set() const {

return _in_collection_set;

}

void set_in_collection_set(bool b) {

_in_collection_set = b;

}

HeapRegion* next_in_collection_set() {

assert(in_collection_set(), "should only invoke on member of CS.");

assert(_next_in_special_set == NULL ||

_next_in_special_set->in_collection_set(),

"Malformed CS.");

return _next_in_special_set;

}

void set_next_in_collection_set(HeapRegion* r) {

assert(in_collection_set(), "should only invoke on member of CS.");

assert(r == NULL || r->in_collection_set(), "Malformed CS.");

_next_in_special_set = r;

}

// Methods used by the HeapRegionSetBase class and subclasses.

// Getter and setter for the next field used to link regions into

// linked lists.

HeapRegion* next() { return _next; }

void set_next(HeapRegion* next) { _next = next; }

// Every region added to a set is tagged with a reference to that

// set. This is used for doing consistency checking to make sure that

// the contents of a set are as they should be and it's only

// available in non-product builds.

#ifdef ASSERT

void set_containing_set(HeapRegionSetBase* containing_set) {

assert((containing_set == NULL && _containing_set != NULL) ||

(containing_set != NULL && _containing_set == NULL),

err_msg("containing_set: "PTR_FORMAT" "

"_containing_set: "PTR_FORMAT,

containing_set, _containing_set));

_containing_set = containing_set;

}

HeapRegionSetBase* containing_set() { return _containing_set; }

#else // ASSERT

void set_containing_set(HeapRegionSetBase* containing_set) { }

// containing_set() is only used in asserts so there's no reason

// to provide a dummy version of it.

#endif // ASSERT

// If we want to remove regions from a list in bulk we can simply tag

// them with the pending_removal tag and call the

// remove_all_pending() method on the list.

bool pending_removal() { return _pending_removal; }

void set_pending_removal(bool pending_removal) {

if (pending_removal) {

assert(!_pending_removal && containing_set() != NULL,

"can only set pending removal to true if it's false and "

"the region belongs to a region set");

} else {

assert( _pending_removal && containing_set() == NULL,

"can only set pending removal to false if it's true and "

"the region does not belong to a region set");

}

_pending_removal = pending_removal;

}

HeapRegion* get_next_young_region() { return _next_young_region; }

void set_next_young_region(HeapRegion* hr) {

_next_young_region = hr;

}

HeapRegion* get_next_dirty_cards_region() const { return _next_dirty_cards_region; }

HeapRegion** next_dirty_cards_region_addr() { return &_next_dirty_cards_region; }

void set_next_dirty_cards_region(HeapRegion* hr) { _next_dirty_cards_region = hr; }

bool is_on_dirty_cards_region_list() const { return get_next_dirty_cards_region() != NULL; }

HeapWord* orig_end() { return _orig_end; }

// Allows logical separation between objects allocated before and after.

void save_marks();

// Reset HR stuff to default values.

void hr_clear(bool par, bool clear_space);

void par_clear();

void initialize(MemRegion mr, bool clear_space, bool mangle_space);

// Get the start of the unmarked area in this region.

HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; }

HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; }

// Apply "cl->do_oop" to (the addresses of) all reference fields in objects

// allocated in the current region before the last call to "save_mark".

void oop_before_save_marks_iterate(OopClosure* cl);

// Note the start or end of marking. This tells the heap region

// that the collector is about to start or has finished (concurrently)

// marking the heap.

// Notify the region that concurrent marking is starting. Initialize

// all fields related to the next marking info.

inline void note_start_of_marking();

// Notify the region that concurrent marking has finished. Copy the

// (now finalized) next marking info fields into the prev marking

// info fields.

inline void note_end_of_marking();

// Notify the region that it will be used as to-space during a GC

// and we are about to start copying objects into it.

inline void note_start_of_copying(bool during_initial_mark);

// Notify the region that it ceases being to-space during a GC and

// we will not copy objects into it any more.

inline void note_end_of_copying(bool during_initial_mark);

// Notify the region that we are about to start processing

// self-forwarded objects during evac failure handling.

void note_self_forwarding_removal_start(bool during_initial_mark,

bool during_conc_mark);

// Notify the region that we have finished processing self-forwarded

// objects during evac failure handling.

void note_self_forwarding_removal_end(bool during_initial_mark,

bool during_conc_mark,

size_t marked_bytes);

// Returns "false" iff no object in the region was allocated when the

// last mark phase ended.

bool is_marked() { return _prev_top_at_mark_start != bottom(); }

void reset_during_compaction() {

assert(isHumongous() && startsHumongous(),

"should only be called for starts humongous regions");

zero_marked_bytes();

init_top_at_mark_start();

}

void calc_gc_efficiency(void);

double gc_efficiency() { return _gc_efficiency;}

bool is_young() const { return _young_type != NotYoung; }

bool is_survivor() const { return _young_type == Survivor; }

int young_index_in_cset() const { return _young_index_in_cset; }

void set_young_index_in_cset(int index) {

assert( (index == -1) || is_young(), "pre-condition" );

_young_index_in_cset = index;

}

int age_in_surv_rate_group() {

assert( _surv_rate_group != NULL, "pre-condition" );

assert( _age_index > -1, "pre-condition" );

return _surv_rate_group->age_in_group(_age_index);

}

void record_surv_words_in_group(size_t words_survived) {

assert( _surv_rate_group != NULL, "pre-condition" );

assert( _age_index > -1, "pre-condition" );

int age_in_group = age_in_surv_rate_group();

_surv_rate_group->record_surviving_words(age_in_group, words_survived);

}

int age_in_surv_rate_group_cond() {

if (_surv_rate_group != NULL)

return age_in_surv_rate_group();

else

return -1;

}

SurvRateGroup* surv_rate_group() {

return _surv_rate_group;

}

void install_surv_rate_group(SurvRateGroup* surv_rate_group) {

assert( surv_rate_group != NULL, "pre-condition" );

assert( _surv_rate_group == NULL, "pre-condition" );

assert( is_young(), "pre-condition" );

_surv_rate_group = surv_rate_group;

_age_index = surv_rate_group->next_age_index();

}

void uninstall_surv_rate_group() {

if (_surv_rate_group != NULL) {

assert( _age_index > -1, "pre-condition" );

assert( is_young(), "pre-condition" );

_surv_rate_group = NULL;

_age_index = -1;

} else {

assert( _age_index == -1, "pre-condition" );

}

}

void set_young() { set_young_type(Young); }

void set_survivor() { set_young_type(Survivor); }

void set_not_young() { set_young_type(NotYoung); }

// Determine if an object has been allocated since the last

// mark performed by the collector. This returns true iff the object

// is within the unmarked area of the region.

bool obj_allocated_since_prev_marking(oop obj) const {

return (HeapWord *) obj >= prev_top_at_mark_start();

}

bool obj_allocated_since_next_marking(oop obj) const {

return (HeapWord *) obj >= next_top_at_mark_start();

}

// For parallel heapRegion traversal.

bool claimHeapRegion(int claimValue);

jint claim_value() { return _claimed; }

// Use this carefully: only when you're sure no one is claiming...

void set_claim_value(int claimValue) { _claimed = claimValue; }

// Returns the "evacuation_failed" property of the region.

bool evacuation_failed() { return _evacuation_failed; }

// Sets the "evacuation_failed" property of the region.

void set_evacuation_failed(bool b) {

_evacuation_failed = b;

if (b) {

_next_marked_bytes = 0;

}

}

// Requires that "mr" be entirely within the region.

// Apply "cl->do_object" to all objects that intersect with "mr".

// If the iteration encounters an unparseable portion of the region,

// or if "cl->abort()" is true after a closure application,

// terminate the iteration and return the address of the start of the

// subregion that isn't done. (The two can be distinguished by querying

// "cl->abort()".) Return of "NULL" indicates that the iteration

// completed.

HeapWord*

object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl);

// filter_young: if true and the region is a young region then we

// skip the iteration.

// card_ptr: if not NULL, and we decide that the card is not young

// and we iterate over it, we'll clean the card before we start the

// iteration.

HeapWord*

oops_on_card_seq_iterate_careful(MemRegion mr,

FilterOutOfRegionClosure* cl,

bool filter_young,

jbyte* card_ptr);

// A version of block start that is guaranteed to find *some* block

// boundary at or before "p", but does not object iteration, and may

// therefore be used safely when the heap is unparseable.

HeapWord* block_start_careful(const void* p) const {

return _offsets.block_start_careful(p);

}

// Requires that "addr" is within the region. Returns the start of the

// first ("careful") block that starts at or after "addr", or else the

// "end" of the region if there is no such block.

HeapWord* next_block_start_careful(HeapWord* addr);

size_t recorded_rs_length() const { return _recorded_rs_length; }

double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; }

size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; }

void set_recorded_rs_length(size_t rs_length) {

_recorded_rs_length = rs_length;

}

void set_predicted_elapsed_time_ms(double ms) {

_predicted_elapsed_time_ms = ms;

}

void set_predicted_bytes_to_copy(size_t bytes) {

_predicted_bytes_to_copy = bytes;

}

#define HeapRegion_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \

virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);

SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DECL)

virtual CompactibleSpace* next_compaction_space() const;

virtual void reset_after_compaction();

void print() const;

void print_on(outputStream* st) const;

// vo == UsePrevMarking -> use "prev" marking information,

// vo == UseNextMarking -> use "next" marking information

// vo == UseMarkWord -> use the mark word in the object header

//

// NOTE: Only the "prev" marking information is guaranteed to be

// consistent most of the time, so most calls to this should use

// vo == UsePrevMarking.

// Currently, there is only one case where this is called with

// vo == UseNextMarking, which is to verify the "next" marking

// information at the end of remark.

// Currently there is only one place where this is called with

// vo == UseMarkWord, which is to verify the marking during a

// full GC.

void verify(VerifyOption vo, bool *failures) const;

// Override; it uses the "prev" marking information

virtual void verify() const;

};

class HeapRegionClosure : public StackObj {

friend class HeapRegionSeq;

friend class G1CollectedHeap;

bool _complete;

void incomplete() { _complete = false; }

public:

HeapRegionClosure(): _complete(true) {}

// Typically called on each region until it returns true.

virtual bool doHeapRegion(HeapRegion* r) = 0;

// True after iteration if the closure was applied to all heap regions

// and returned "false" in all cases.

bool complete() { return _complete; }

};

#endif // SERIALGC

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_HPP