Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/heapRegion.hpp @ 948:89e0543e1737
6884624: Update copyright year
Summary: Update copyright for files that have been modified in 2009 through Septermber
Reviewed-by: tbell, ohair
author | xdono |
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date | Tue, 22 Sep 2009 14:06:10 -0700 |
parents | 2c79770d1f6e |
children | ff2402f6a50b |
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/* * Copyright 2001-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ #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; // 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; }; 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; // True iff the region is on the unclean list, waiting to be zero filled. bool _is_on_unclean_list; // True iff the region is on the free list, ready for allocation. bool _is_on_free_list; // 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; // 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 ScanOnly, // a region is young and scan-only Young, // a region is young Survivor // a region is young and it contains // survivor }; 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; } jint _zfs; // A member of ZeroFillState. Protected by ZF_lock. Thread* _zero_filler; // If _zfs is ZeroFilling, the thread that (last) // made it so. 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; } 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 }; // Concurrent refinement requires contiguous heap regions (in which TLABs // might be allocated) to be zero-filled. Each region therefore has a // zero-fill-state. enum ZeroFillState { NotZeroFilled, ZeroFilling, ZeroFilled, Allocated }; // 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; } // Causes the current region to represent a humongous object spanning "n" // regions. virtual void set_startsHumongous(); // The regions that continue a humongous sequence should be added using // this method, in increasing address order. void set_continuesHumongous(HeapRegion* start); void add_continuingHumongousRegion(HeapRegion* cont); // 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; } bool is_on_free_list() { return _is_on_free_list; } void set_on_free_list(bool b) { _is_on_free_list = b; } HeapRegion* next_from_free_list() { assert(is_on_free_list(), "Should only invoke on free space."); assert(_next_in_special_set == NULL || _next_in_special_set->is_on_free_list(), "Malformed Free List."); return _next_in_special_set; } void set_next_on_free_list(HeapRegion* r) { assert(r == NULL || r->is_on_free_list(), "Malformed free list."); _next_in_special_set = r; } bool is_on_unclean_list() { return _is_on_unclean_list; } void set_on_unclean_list(bool b); HeapRegion* next_from_unclean_list() { assert(is_on_unclean_list(), "Should only invoke on unclean space."); assert(_next_in_special_set == NULL || _next_in_special_set->is_on_unclean_list(), "Malformed unclean List."); return _next_in_special_set; } void set_next_on_unclean_list(HeapRegion* r); 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); // Ensure that "this" is zero-filled. void ensure_zero_filled(); // This one requires that the calling thread holds ZF_mon. void ensure_zero_filled_locked(); // 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"); // Survivor regions will be scanned on the start of concurrent // marking. if (!is_survivor()) { _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_scan_only() const { return _young_type == ScanOnly; } 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 recalculate_age_in_surv_rate_group() { assert( _surv_rate_group != NULL, "pre-condition" ); assert( _age_index > -1, "pre-condition" ); _age_index = _surv_rate_group->recalculate_age_index(_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_scan_only() { set_young_type(ScanOnly); } 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); HeapWord* oops_on_card_seq_iterate_careful(MemRegion mr, FilterOutOfRegionClosure* cl); // The region "mr" is entirely in "this", and starts and ends at block // boundaries. The caller declares that all the contained blocks are // coalesced into one. void declare_filled_region_to_BOT(MemRegion mr) { _offsets.single_block(mr.start(), mr.end()); } // 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); // Returns the zero-fill-state of the current region. ZeroFillState zero_fill_state() { return (ZeroFillState)_zfs; } bool zero_fill_is_allocated() { return _zfs == Allocated; } Thread* zero_filler() { return _zero_filler; } // Indicate that the contents of the region are unknown, and therefore // might require zero-filling. void set_zero_fill_needed() { set_zero_fill_state_work(NotZeroFilled); } void set_zero_fill_in_progress(Thread* t) { set_zero_fill_state_work(ZeroFilling); _zero_filler = t; } void set_zero_fill_complete(); void set_zero_fill_allocated() { set_zero_fill_state_work(Allocated); } void set_zero_fill_state_work(ZeroFillState zfs); // This is called when a full collection shrinks the heap. // We want to set the heap region to a value which says // it is no longer part of the heap. For now, we'll let "NotZF" fill // that role. void reset_zero_fill() { set_zero_fill_state_work(NotZeroFilled); _zero_filler = NULL; } #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) const; // Override; it uses the "prev" marking information virtual void verify(bool allow_dirty) const; #ifdef DEBUG HeapWord* allocate(size_t size); #endif }; // 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; } }; // A linked lists of heap regions. It leaves the "next" field // unspecified; that's up to subtypes. class RegionList VALUE_OBJ_CLASS_SPEC { protected: virtual HeapRegion* get_next(HeapRegion* chr) = 0; virtual void set_next(HeapRegion* chr, HeapRegion* new_next) = 0; HeapRegion* _hd; HeapRegion* _tl; size_t _sz; // Protected constructor because this type is only meaningful // when the _get/_set next functions are defined. RegionList() : _hd(NULL), _tl(NULL), _sz(0) {} public: void reset() { _hd = NULL; _tl = NULL; _sz = 0; } HeapRegion* hd() { return _hd; } HeapRegion* tl() { return _tl; } size_t sz() { return _sz; } size_t length(); bool well_formed() { return ((hd() == NULL && tl() == NULL && sz() == 0) || (hd() != NULL && tl() != NULL && sz() > 0)) && (sz() == length()); } virtual void insert_before_head(HeapRegion* r); void prepend_list(RegionList* new_list); virtual HeapRegion* pop(); void dec_sz() { _sz--; } // Requires that "r" is an element of the list, and is not the tail. void delete_after(HeapRegion* r); }; class EmptyNonHRegionList: public RegionList { protected: // Protected constructor because this type is only meaningful // when the _get/_set next functions are defined. EmptyNonHRegionList() : RegionList() {} public: void insert_before_head(HeapRegion* r) { // assert(r->is_empty(), "Better be empty"); assert(!r->isHumongous(), "Better not be humongous."); RegionList::insert_before_head(r); } void prepend_list(EmptyNonHRegionList* new_list) { // assert(new_list->hd() == NULL || new_list->hd()->is_empty(), // "Better be empty"); assert(new_list->hd() == NULL || !new_list->hd()->isHumongous(), "Better not be humongous."); // assert(new_list->tl() == NULL || new_list->tl()->is_empty(), // "Better be empty"); assert(new_list->tl() == NULL || !new_list->tl()->isHumongous(), "Better not be humongous."); RegionList::prepend_list(new_list); } }; class UncleanRegionList: public EmptyNonHRegionList { public: HeapRegion* get_next(HeapRegion* hr) { return hr->next_from_unclean_list(); } void set_next(HeapRegion* hr, HeapRegion* new_next) { hr->set_next_on_unclean_list(new_next); } UncleanRegionList() : EmptyNonHRegionList() {} void insert_before_head(HeapRegion* r) { assert(!r->is_on_free_list(), "Better not already be on free list"); assert(!r->is_on_unclean_list(), "Better not already be on unclean list"); r->set_zero_fill_needed(); r->set_on_unclean_list(true); EmptyNonHRegionList::insert_before_head(r); } void prepend_list(UncleanRegionList* new_list) { assert(new_list->tl() == NULL || !new_list->tl()->is_on_free_list(), "Better not already be on free list"); assert(new_list->tl() == NULL || new_list->tl()->is_on_unclean_list(), "Better already be marked as on unclean list"); assert(new_list->hd() == NULL || !new_list->hd()->is_on_free_list(), "Better not already be on free list"); assert(new_list->hd() == NULL || new_list->hd()->is_on_unclean_list(), "Better already be marked as on unclean list"); EmptyNonHRegionList::prepend_list(new_list); } HeapRegion* pop() { HeapRegion* res = RegionList::pop(); if (res != NULL) res->set_on_unclean_list(false); return res; } }; // Local Variables: *** // c-indentation-style: gnu *** // End: *** #endif // SERIALGC