| /* |
| * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #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 |
| |
| // A HeapRegion is the smallest piece of a G1CollectedHeap that |
| // can be collected independently. |
| |
| // NOTE: Although a HeapRegion is a Space, its |
| // Space::initDirtyCardClosure method must not be called. |
| // The problem is that the existence of this method breaks |
| // the independence of barrier sets from remembered sets. |
| // The solution is to remove this method from the definition |
| // of a Space. |
| |
| class CompactibleSpace; |
| class ContiguousSpace; |
| class HeapRegionRemSet; |
| class HeapRegionRemSetIterator; |
| class HeapRegion; |
| class HeapRegionSetBase; |
| |
| #define HR_FORMAT "%d:["PTR_FORMAT","PTR_FORMAT","PTR_FORMAT"]" |
| #define HR_FORMAT_PARAMS(__hr) (__hr)->hrs_index(), (__hr)->bottom(), \ |
| (__hr)->top(), (__hr)->end() |
| |
| // A dirty card to oop closure for heap regions. It |
| // knows how to get the G1 heap and how to use the bitmap |
| // in the concurrent marker used by G1 to filter remembered |
| // sets. |
| |
| 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); |
| }; |
| |
| |
| // The complicating factor is that BlockOffsetTable diverged |
| // significantly, and we need functionality that is only in the G1 version. |
| // So I copied that code, which led to an alternate G1 version of |
| // OffsetTableContigSpace. If the two versions of BlockOffsetTable could |
| // be reconciled, then G1OffsetTableContigSpace could go away. |
| |
| // The idea behind time stamps is the following. Doing a save_marks on |
| // all regions at every GC pause is time consuming (if I remember |
| // well, 10ms or so). So, we would like to do that only for regions |
| // that are GC alloc regions. To achieve this, we use time |
| // stamps. For every evacuation pause, G1CollectedHeap generates a |
| // unique time stamp (essentially a counter that gets |
| // incremented). Every time we want to call save_marks on a region, |
| // we set the saved_mark_word to top and also copy the current GC |
| // time stamp to the time stamp field of the space. Reading the |
| // saved_mark_word involves checking the time stamp of the |
| // region. If it is the same as the current GC time stamp, then we |
| // can safely read the saved_mark_word field, as it is valid. If the |
| // time stamp of the region is not the same as the current GC time |
| // stamp, then we instead read top, as the saved_mark_word field is |
| // invalid. Time stamps (on the regions and also on the |
| // G1CollectedHeap) are reset at every cleanup (we iterate over |
| // the regions anyway) and at the end of a Full GC. The current scheme |
| // that uses sequential unsigned ints will fail only if we have 4b |
| // evacuation pauses between two cleanups, which is _highly_ unlikely. |
| |
| class G1OffsetTableContigSpace: public ContiguousSpace { |
| friend class VMStructs; |
| protected: |
| G1BlockOffsetArrayContigSpace _offsets; |
| Mutex _par_alloc_lock; |
| volatile unsigned _gc_time_stamp; |
| |
| 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; } |
| |
| 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 |
| }; |
| |
| // The next filter kind that should be used for a "new_dcto_cl" call with |
| // the "traditional" signature. |
| HeapRegionDCTOC::FilterKind _next_fk; |
| |
| // 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: |
| // If this region is a member of a HeapRegionSeq, the index in that |
| // sequence, otherwise -1. |
| int _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; |
| |
| // Is this or has it been an allocation region in the current collection |
| // pause. |
| bool _is_gc_alloc_region; |
| |
| // 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. |
| |
| // See "sort_index" method. -1 means is not in the array. |
| int _sort_index; |
| |
| // <PREDICTION> |
| double _gc_efficiency; |
| // </PREDICTION> |
| |
| enum YoungType { |
| NotYoung, // a region is not young |
| Young, // a region is young |
| Survivor // a region is young and it contains |
| // survivor |
| }; |
| |
| 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. |
| |
| // We've counted the marked bytes of objects below here. |
| HeapWord* _top_at_conc_mark_count; |
| |
| 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; |
| _top_at_conc_mark_count = 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(G1BlockOffsetSharedArray* sharedOffsetArray, |
| MemRegion mr, bool is_zeroed); |
| |
| static int LogOfHRGrainBytes; |
| static int LogOfHRGrainWords; |
| // The normal type of these should be size_t. However, they used to |
| // be members of an enum before and they are assumed by the |
| // compilers to be ints. To avoid going and fixing all their uses, |
| // I'm declaring them as ints. I'm not anticipating heap region |
| // sizes to reach anywhere near 2g, so using an int here is safe. |
| static int GrainBytes; |
| static int GrainWords; |
| static int CardsPerRegion; |
| |
| // 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 |
| }; |
| |
| 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. |
| int hrs_index() const { return _hrs_index; } |
| void set_hrs_index(int index) { _hrs_index = index; } |
| |
| // The number of bytes marked live in the region in the last marking phase. |
| size_t marked_bytes() { return _prev_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(); |
| } |
| |
| // 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; |
| guarantee( _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; |
| } |
| |
| // 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; |
| } |
| |
| // True iff it is or has been an allocation region in the current |
| // collection pause. |
| bool is_gc_alloc_region() const { |
| return _is_gc_alloc_region; |
| } |
| void set_is_gc_alloc_region(bool b) { |
| _is_gc_alloc_region = b; |
| } |
| HeapRegion* next_gc_alloc_region() { |
| assert(is_gc_alloc_region(), "should only invoke on member of CS."); |
| assert(_next_in_special_set == NULL || |
| _next_in_special_set->is_gc_alloc_region(), |
| "Malformed CS."); |
| return _next_in_special_set; |
| } |
| void set_next_gc_alloc_region(HeapRegion* r) { |
| assert(is_gc_alloc_region(), "should only invoke on member of CS."); |
| assert(r == NULL || r->is_gc_alloc_region(), "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 not 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) { |
| // We can only set pending_removal to true, if it's false and the |
| // region belongs to a set. |
| assert(!pending_removal || |
| (!_pending_removal && containing_set() != NULL), "pre-condition"); |
| // We can only set pending_removal to false, if it's true and the |
| // region does not belong to a set. |
| assert( pending_removal || |
| ( _pending_removal && containing_set() == NULL), "pre-condition"); |
| |
| _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; } |
| |
| // 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 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); |
| |
| // This call determines the "filter kind" argument that will be used for |
| // the next call to "new_dcto_cl" on this region with the "traditional" |
| // signature (i.e., the call below.) The default, in the absence of a |
| // preceding call to this method, is "NoFilterKind", and a call to this |
| // method is necessary for each such call, or else it reverts to the |
| // default. |
| // (This is really ugly, but all other methods I could think of changed a |
| // lot of main-line code for G1.) |
| void set_next_filter_kind(HeapRegionDCTOC::FilterKind nfk) { |
| _next_fk = nfk; |
| } |
| |
| DirtyCardToOopClosure* |
| new_dcto_closure(OopClosure* cl, |
| CardTableModRefBS::PrecisionStyle precision, |
| HeapRegionDCTOC::FilterKind fk); |
| |
| #if WHASSUP |
| DirtyCardToOopClosure* |
| new_dcto_closure(OopClosure* cl, |
| CardTableModRefBS::PrecisionStyle precision, |
| HeapWord* boundary) { |
| assert(boundary == NULL, "This arg doesn't make sense here."); |
| DirtyCardToOopClosure* res = new_dcto_closure(cl, precision, _next_fk); |
| _next_fk = HeapRegionDCTOC::NoFilterKind; |
| return res; |
| } |
| #endif |
| |
| // |
| // 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. |
| // |
| |
| // Note the start of a marking phase. Record the |
| // start of the unmarked area of the region here. |
| void note_start_of_marking(bool during_initial_mark) { |
| init_top_at_conc_mark_count(); |
| _next_marked_bytes = 0; |
| if (during_initial_mark && is_young() && !is_survivor()) |
| _next_top_at_mark_start = bottom(); |
| else |
| _next_top_at_mark_start = top(); |
| } |
| |
| // Note the end of a marking phase. Install the start of |
| // the unmarked area that was captured at start of marking. |
| void note_end_of_marking() { |
| _prev_top_at_mark_start = _next_top_at_mark_start; |
| _prev_marked_bytes = _next_marked_bytes; |
| _next_marked_bytes = 0; |
| |
| guarantee(_prev_marked_bytes <= |
| (size_t) (prev_top_at_mark_start() - bottom()) * HeapWordSize, |
| "invariant"); |
| } |
| |
| // After an evacuation, we need to update _next_top_at_mark_start |
| // to be the current top. Note this is only valid if we have only |
| // ever evacuated into this region. If we evacuate, allocate, and |
| // then evacuate we are in deep doodoo. |
| void note_end_of_copying() { |
| assert(top() >= _next_top_at_mark_start, "Increase only"); |
| _next_top_at_mark_start = top(); |
| } |
| |
| // 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(); } |
| |
| // If "is_marked()" is true, then this is the index of the region in |
| // an array constructed at the end of marking of the regions in a |
| // "desirability" order. |
| int sort_index() { |
| return _sort_index; |
| } |
| void set_sort_index(int i) { |
| _sort_index = i; |
| } |
| |
| void init_top_at_conc_mark_count() { |
| _top_at_conc_mark_count = bottom(); |
| } |
| |
| void set_top_at_conc_mark_count(HeapWord *cur) { |
| assert(bottom() <= cur && cur <= end(), "Sanity."); |
| _top_at_conc_mark_count = cur; |
| } |
| |
| HeapWord* top_at_conc_mark_count() { |
| return _top_at_conc_mark_count; |
| } |
| |
| void reset_during_compaction() { |
| guarantee( isHumongous() && startsHumongous(), |
| "should only be called for humongous regions"); |
| |
| zero_marked_bytes(); |
| init_top_at_mark_start(); |
| } |
| |
| // <PREDICTION> |
| void calc_gc_efficiency(void); |
| double gc_efficiency() { return _gc_efficiency;} |
| // </PREDICTION> |
| |
| 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) { |
| init_top_at_conc_mark_count(); |
| _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); |
| |
| // In this version - if filter_young is true and the region |
| // is a young region then we skip the iteration. |
| HeapWord* |
| oops_on_card_seq_iterate_careful(MemRegion mr, |
| FilterOutOfRegionClosure* cl, |
| bool filter_young); |
| |
| // 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) |
| |
| CompactibleSpace* next_compaction_space() const; |
| |
| virtual void reset_after_compaction(); |
| |
| void print() const; |
| void print_on(outputStream* st) const; |
| |
| // use_prev_marking == true -> use "prev" marking information, |
| // use_prev_marking == false -> use "next" marking information |
| // NOTE: Only the "prev" marking information is guaranteed to be |
| // consistent most of the time, so most calls to this should use |
| // use_prev_marking == true. Currently, there is only one case where |
| // this is called with use_prev_marking == false, which is to verify |
| // the "next" marking information at the end of remark. |
| void verify(bool allow_dirty, bool use_prev_marking, bool *failures) const; |
| |
| // Override; it uses the "prev" marking information |
| virtual void verify(bool allow_dirty) const; |
| }; |
| |
| // HeapRegionClosure is used for iterating over regions. |
| // Terminates the iteration when the "doHeapRegion" method returns "true". |
| 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 |