ysr@777: /*
xdono@1014:  * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
ysr@777:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777:  *
ysr@777:  * This code is free software; you can redistribute it and/or modify it
ysr@777:  * under the terms of the GNU General Public License version 2 only, as
ysr@777:  * published by the Free Software Foundation.
ysr@777:  *
ysr@777:  * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ysr@777:  * version 2 for more details (a copy is included in the LICENSE file that
ysr@777:  * accompanied this code).
ysr@777:  *
ysr@777:  * You should have received a copy of the GNU General Public License version
ysr@777:  * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777:  *
ysr@777:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
ysr@777:  * CA 95054 USA or visit www.sun.com if you need additional information or
ysr@777:  * have any questions.
ysr@777:  *
ysr@777:  */
ysr@777: 
ysr@777: // A G1RemSet provides ways of iterating over pointers into a selected
ysr@777: // collection set.
ysr@777: 
ysr@777: class G1CollectedHeap;
ysr@777: class CardTableModRefBarrierSet;
ysr@777: class HRInto_G1RemSet;
ysr@777: class ConcurrentG1Refine;
ysr@777: 
apetrusenko@984: class G1RemSet: public CHeapObj {
ysr@777: protected:
ysr@777:   G1CollectedHeap* _g1;
ysr@777: 
ysr@777:   unsigned _conc_refine_traversals;
ysr@777:   unsigned _conc_refine_cards;
ysr@777: 
ysr@777:   size_t n_workers();
ysr@777: 
ysr@777: public:
ysr@777:   G1RemSet(G1CollectedHeap* g1) :
ysr@777:     _g1(g1), _conc_refine_traversals(0), _conc_refine_cards(0)
ysr@777:   {}
ysr@777: 
ysr@777:   // Invoke "blk->do_oop" on all pointers into the CS in object in regions
ysr@777:   // outside the CS (having invoked "blk->set_region" to set the "from"
ysr@777:   // region correctly beforehand.) The "worker_i" param is for the
ysr@777:   // parallel case where the number of the worker thread calling this
ysr@777:   // function can be helpful in partitioning the work to be done. It
ysr@777:   // should be the same as the "i" passed to the calling thread's
ysr@777:   // work(i) function. In the sequential case this param will be ingored.
ysr@777:   virtual void oops_into_collection_set_do(OopsInHeapRegionClosure* blk,
ysr@777:                                            int worker_i) = 0;
ysr@777: 
ysr@777:   // Prepare for and cleanup after an oops_into_collection_set_do
ysr@777:   // call.  Must call each of these once before and after (in sequential
ysr@777:   // code) any threads call oops into collection set do.  (This offers an
ysr@777:   // opportunity to sequential setup and teardown of structures needed by a
ysr@777:   // parallel iteration over the CS's RS.)
ysr@777:   virtual void prepare_for_oops_into_collection_set_do() = 0;
ysr@777:   virtual void cleanup_after_oops_into_collection_set_do() = 0;
ysr@777: 
ysr@777:   // If "this" is of the given subtype, return "this", else "NULL".
ysr@777:   virtual HRInto_G1RemSet* as_HRInto_G1RemSet() { return NULL; }
ysr@777: 
ysr@777:   // Record, if necessary, the fact that *p (where "p" is in region "from")
ysr@777:   // has changed to its new value.
ysr@777:   virtual void write_ref(HeapRegion* from, oop* p) = 0;
ysr@777:   virtual void par_write_ref(HeapRegion* from, oop* p, int tid) = 0;
ysr@777: 
ysr@777:   // Requires "region_bm" and "card_bm" to be bitmaps with 1 bit per region
ysr@777:   // or card, respectively, such that a region or card with a corresponding
ysr@777:   // 0 bit contains no part of any live object.  Eliminates any remembered
ysr@777:   // set entries that correspond to dead heap ranges.
ysr@777:   virtual void scrub(BitMap* region_bm, BitMap* card_bm) = 0;
ysr@777:   // Like the above, but assumes is called in parallel: "worker_num" is the
ysr@777:   // parallel thread id of the current thread, and "claim_val" is the
ysr@777:   // value that should be used to claim heap regions.
ysr@777:   virtual void scrub_par(BitMap* region_bm, BitMap* card_bm,
ysr@777:                          int worker_num, int claim_val) = 0;
ysr@777: 
ysr@777:   // Do any "refinement" activity that might be appropriate to the given
ysr@777:   // G1RemSet.  If "refinement" has iterateive "passes", do one pass.
ysr@777:   // If "t" is non-NULL, it is the thread performing the refinement.
ysr@777:   // Default implementation does nothing.
ysr@777:   virtual void concurrentRefinementPass(ConcurrentG1Refine* cg1r) {}
ysr@777: 
ysr@777:   // Refine the card corresponding to "card_ptr".  If "sts" is non-NULL,
ysr@777:   // join and leave around parts that must be atomic wrt GC.  (NULL means
ysr@777:   // being done at a safepoint.)
ysr@777:   virtual void concurrentRefineOneCard(jbyte* card_ptr, int worker_i) {}
ysr@777: 
ysr@777:   unsigned conc_refine_cards() { return _conc_refine_cards; }
ysr@777: 
ysr@777:   // Print any relevant summary info.
ysr@777:   virtual void print_summary_info() {}
ysr@777: 
ysr@777:   // Prepare remebered set for verification.
ysr@777:   virtual void prepare_for_verify() {};
ysr@777: };
ysr@777: 
ysr@777: 
ysr@777: // The simplest possible G1RemSet: iterates over all objects in non-CS
ysr@777: // regions, searching for pointers into the CS.
ysr@777: class StupidG1RemSet: public G1RemSet {
ysr@777: public:
ysr@777:   StupidG1RemSet(G1CollectedHeap* g1) : G1RemSet(g1) {}
ysr@777: 
ysr@777:   void oops_into_collection_set_do(OopsInHeapRegionClosure* blk,
ysr@777:                                    int worker_i);
ysr@777: 
ysr@777:   void prepare_for_oops_into_collection_set_do() {}
ysr@777:   void cleanup_after_oops_into_collection_set_do() {}
ysr@777: 
ysr@777:   // Nothing is necessary in the version below.
ysr@777:   void write_ref(HeapRegion* from, oop* p) {}
ysr@777:   void par_write_ref(HeapRegion* from, oop* p, int tid) {}
ysr@777: 
ysr@777:   void scrub(BitMap* region_bm, BitMap* card_bm) {}
ysr@777:   void scrub_par(BitMap* region_bm, BitMap* card_bm,
ysr@777:                  int worker_num, int claim_val) {}
ysr@777: 
ysr@777: };
ysr@777: 
ysr@777: // A G1RemSet in which each heap region has a rem set that records the
ysr@777: // external heap references into it.  Uses a mod ref bs to track updates,
ysr@777: // so that they can be used to update the individual region remsets.
ysr@777: 
ysr@777: class HRInto_G1RemSet: public G1RemSet {
ysr@777: protected:
ysr@777:   enum SomePrivateConstants {
ysr@777:     UpdateRStoMergeSync  = 0,
ysr@777:     MergeRStoDoDirtySync = 1,
ysr@777:     DoDirtySync          = 2,
ysr@777:     LastSync             = 3,
ysr@777: 
ysr@777:     SeqTask              = 0,
ysr@777:     NumSeqTasks          = 1
ysr@777:   };
ysr@777: 
ysr@777:   CardTableModRefBS*             _ct_bs;
ysr@777:   SubTasksDone*                  _seq_task;
ysr@777:   G1CollectorPolicy* _g1p;
ysr@777: 
ysr@777:   ConcurrentG1Refine* _cg1r;
ysr@777: 
ysr@777:   size_t*             _cards_scanned;
ysr@777:   size_t              _total_cards_scanned;
ysr@777: 
ysr@777:   // _par_traversal_in_progress is "true" iff a parallel traversal is in
ysr@777:   // progress.  If so, then cards added to remembered sets should also have
ysr@777:   // their references into the collection summarized in "_new_refs".
ysr@777:   bool _par_traversal_in_progress;
ysr@777:   void set_par_traversal(bool b);
ysr@777:   GrowableArray<oop*>** _new_refs;
iveresov@1051:   void new_refs_iterate(OopClosure* cl);
ysr@777: 
ysr@777: public:
ysr@777:   // This is called to reset dual hash tables after the gc pause
ysr@777:   // is finished and the initial hash table is no longer being
ysr@777:   // scanned.
ysr@777:   void cleanupHRRS();
ysr@777: 
ysr@777:   HRInto_G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs);
ysr@777:   ~HRInto_G1RemSet();
ysr@777: 
ysr@777:   void oops_into_collection_set_do(OopsInHeapRegionClosure* blk,
ysr@777:                                    int worker_i);
ysr@777: 
ysr@777:   void prepare_for_oops_into_collection_set_do();
ysr@777:   void cleanup_after_oops_into_collection_set_do();
ysr@777:   void scanRS(OopsInHeapRegionClosure* oc, int worker_i);
ysr@777:   void scanNewRefsRS(OopsInHeapRegionClosure* oc, int worker_i);
ysr@777:   void updateRS(int worker_i);
ysr@777:   HeapRegion* calculateStartRegion(int i);
ysr@777: 
ysr@777:   HRInto_G1RemSet* as_HRInto_G1RemSet() { return this; }
ysr@777: 
ysr@777:   CardTableModRefBS* ct_bs() { return _ct_bs; }
ysr@777:   size_t cardsScanned() { return _total_cards_scanned; }
ysr@777: 
ysr@777:   // Record, if necessary, the fact that *p (where "p" is in region "from",
ysr@777:   // which is required to be non-NULL) has changed to a new non-NULL value.
ysr@777:   inline void write_ref(HeapRegion* from, oop* p);
ysr@777:   // The "_nv" version is the same; it exists just so that it is not virtual.
ysr@777:   inline void write_ref_nv(HeapRegion* from, oop* p);
ysr@777: 
ysr@777:   inline bool self_forwarded(oop obj);
ysr@777:   inline void par_write_ref(HeapRegion* from, oop* p, int tid);
ysr@777: 
ysr@777:   void scrub(BitMap* region_bm, BitMap* card_bm);
ysr@777:   void scrub_par(BitMap* region_bm, BitMap* card_bm,
ysr@777:                  int worker_num, int claim_val);
ysr@777: 
ysr@777:   virtual void concurrentRefinementPass(ConcurrentG1Refine* t);
ysr@777:   virtual void concurrentRefineOneCard(jbyte* card_ptr, int worker_i);
ysr@777: 
ysr@777:   virtual void print_summary_info();
ysr@777:   virtual void prepare_for_verify();
ysr@777: };
ysr@777: 
ysr@777: #define G1_REM_SET_LOGGING 0
ysr@777: 
ysr@777: class CountNonCleanMemRegionClosure: public MemRegionClosure {
ysr@777:   G1CollectedHeap* _g1;
ysr@777:   int _n;
ysr@777:   HeapWord* _start_first;
ysr@777: public:
ysr@777:   CountNonCleanMemRegionClosure(G1CollectedHeap* g1) :
ysr@777:     _g1(g1), _n(0), _start_first(NULL)
ysr@777:   {}
ysr@777:   void do_MemRegion(MemRegion mr);
ysr@777:   int n() { return _n; };
ysr@777:   HeapWord* start_first() { return _start_first; }
ysr@777: };
apetrusenko@1061: 
apetrusenko@1061: class UpdateRSOopClosure: public OopClosure {
apetrusenko@1061:   HeapRegion* _from;
apetrusenko@1061:   HRInto_G1RemSet* _rs;
apetrusenko@1061:   int _worker_i;
apetrusenko@1061: public:
apetrusenko@1061:   UpdateRSOopClosure(HRInto_G1RemSet* rs, int worker_i = 0) :
apetrusenko@1061:     _from(NULL), _rs(rs), _worker_i(worker_i) {
apetrusenko@1061:     guarantee(_rs != NULL, "Requires an HRIntoG1RemSet");
apetrusenko@1061:   }
apetrusenko@1061: 
apetrusenko@1061:   void set_from(HeapRegion* from) {
apetrusenko@1061:     assert(from != NULL, "from region must be non-NULL");
apetrusenko@1061:     _from = from;
apetrusenko@1061:   }
apetrusenko@1061: 
apetrusenko@1061:   virtual void do_oop(narrowOop* p);
apetrusenko@1061:   virtual void do_oop(oop* p);
apetrusenko@1061: 
apetrusenko@1061:   // Override: this closure is idempotent.
apetrusenko@1061:   //  bool idempotent() { return true; }
apetrusenko@1061:   bool apply_to_weak_ref_discovered_field() { return true; }
apetrusenko@1061: };
apetrusenko@1061: