duke@435: /*
duke@435:  * Copyright 2001-2006 Sun Microsystems, Inc.  All Rights Reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: class Space;
duke@435: class OopsInGenClosure;
duke@435: class DirtyCardToOopClosure;
duke@435: 
duke@435: // This kind of "GenRemSet" uses a card table both as shared data structure
duke@435: // for a mod ref barrier set and for the rem set information.
duke@435: 
duke@435: class CardTableRS: public GenRemSet {
duke@435:   friend class VMStructs;
duke@435:   // Below are private classes used in impl.
duke@435:   friend class VerifyCTSpaceClosure;
duke@435:   friend class ClearNoncleanCardWrapper;
duke@435: 
duke@435:   static jbyte clean_card_val() {
duke@435:     return CardTableModRefBS::clean_card;
duke@435:   }
duke@435: 
duke@435:   static bool
duke@435:   card_is_dirty_wrt_gen_iter(jbyte cv) {
duke@435:     return CardTableModRefBS::card_is_dirty_wrt_gen_iter(cv);
duke@435:   }
duke@435: 
duke@435:   CardTableModRefBSForCTRS _ct_bs;
duke@435: 
duke@435:   virtual void younger_refs_in_space_iterate(Space* sp, OopsInGenClosure* cl);
duke@435: 
duke@435:   void verify_space(Space* s, HeapWord* gen_start);
duke@435: 
duke@435:   enum ExtendedCardValue {
duke@435:     youngergen_card   = CardTableModRefBS::CT_MR_BS_last_reserved + 1,
duke@435:     // These are for parallel collection.
duke@435:     // There are three P (parallel) youngergen card values.  In general, this
duke@435:     // needs to be more than the number of generations (including the perm
duke@435:     // gen) that might have younger_refs_do invoked on them separately.  So
duke@435:     // if we add more gens, we have to add more values.
duke@435:     youngergenP1_card  = CardTableModRefBS::CT_MR_BS_last_reserved + 2,
duke@435:     youngergenP2_card  = CardTableModRefBS::CT_MR_BS_last_reserved + 3,
duke@435:     youngergenP3_card  = CardTableModRefBS::CT_MR_BS_last_reserved + 4,
duke@435:     cur_youngergen_and_prev_nonclean_card =
duke@435:       CardTableModRefBS::CT_MR_BS_last_reserved + 5
duke@435:   };
duke@435: 
duke@435:   // An array that contains, for each generation, the card table value last
duke@435:   // used as the current value for a younger_refs_do iteration of that
duke@435:   // portion of the table.  (The perm gen is index 0; other gens are at
duke@435:   // their level plus 1.  They youngest gen is in the table, but will
duke@435:   // always have the value "clean_card".)
duke@435:   jbyte* _last_cur_val_in_gen;
duke@435: 
duke@435:   jbyte _cur_youngergen_card_val;
duke@435: 
duke@435:   jbyte cur_youngergen_card_val() {
duke@435:     return _cur_youngergen_card_val;
duke@435:   }
duke@435:   void set_cur_youngergen_card_val(jbyte v) {
duke@435:     _cur_youngergen_card_val = v;
duke@435:   }
duke@435:   bool is_prev_youngergen_card_val(jbyte v) {
duke@435:     return
duke@435:       youngergen_card <= v &&
duke@435:       v < cur_youngergen_and_prev_nonclean_card &&
duke@435:       v != _cur_youngergen_card_val;
duke@435:   }
duke@435:   // Return a youngergen_card_value that is not currently in use.
duke@435:   jbyte find_unused_youngergenP_card_value();
duke@435: 
duke@435: public:
duke@435:   CardTableRS(MemRegion whole_heap, int max_covered_regions);
duke@435: 
duke@435:   // *** GenRemSet functions.
duke@435:   GenRemSet::Name rs_kind() { return GenRemSet::CardTable; }
duke@435: 
duke@435:   CardTableRS* as_CardTableRS() { return this; }
duke@435: 
duke@435:   CardTableModRefBS* ct_bs() { return &_ct_bs; }
duke@435: 
duke@435:   // Override.
duke@435:   void prepare_for_younger_refs_iterate(bool parallel);
duke@435: 
duke@435:   // Card table entries are cleared before application; "blk" is
duke@435:   // responsible for dirtying if the oop is still older-to-younger after
duke@435:   // closure application.
duke@435:   void younger_refs_iterate(Generation* g, OopsInGenClosure* blk);
duke@435: 
duke@435:   void inline_write_ref_field_gc(oop* field, oop new_val) {
duke@435:     jbyte* byte = _ct_bs.byte_for(field);
duke@435:     *byte = youngergen_card;
duke@435:   }
duke@435:   void write_ref_field_gc_work(oop* field, oop new_val) {
duke@435:     inline_write_ref_field_gc(field, new_val);
duke@435:   }
duke@435: 
duke@435:   // Override.  Might want to devirtualize this in the same fashion as
duke@435:   // above.  Ensures that the value of the card for field says that it's
duke@435:   // a younger card in the current collection.
duke@435:   virtual void write_ref_field_gc_par(oop* field, oop new_val);
duke@435: 
duke@435:   void resize_covered_region(MemRegion new_region);
duke@435: 
duke@435:   bool is_aligned(HeapWord* addr) {
duke@435:     return _ct_bs.is_card_aligned(addr);
duke@435:   }
duke@435: 
duke@435:   void verify();
duke@435:   void verify_empty(MemRegion mr);
duke@435: 
duke@435:   void clear(MemRegion mr) { _ct_bs.clear(mr); }
duke@435:   void clear_into_younger(Generation* gen, bool clear_perm);
duke@435: 
duke@435:   void invalidate(MemRegion mr) { _ct_bs.invalidate(mr); }
duke@435:   void invalidate_or_clear(Generation* gen, bool younger, bool perm);
duke@435: 
duke@435:   static uintx ct_max_alignment_constraint() {
duke@435:     return CardTableModRefBS::ct_max_alignment_constraint();
duke@435:   }
duke@435: 
duke@435:   jbyte* byte_for(void* p)     { return _ct_bs.byte_for(p); }
duke@435:   jbyte* byte_after(void* p)   { return _ct_bs.byte_after(p); }
duke@435:   HeapWord* addr_for(jbyte* p) { return _ct_bs.addr_for(p); }
duke@435: 
duke@435:   bool is_prev_nonclean_card_val(jbyte v) {
duke@435:     return
duke@435:       youngergen_card <= v &&
duke@435:       v <= cur_youngergen_and_prev_nonclean_card &&
duke@435:       v != _cur_youngergen_card_val;
duke@435:   }
duke@435: 
duke@435:   static bool youngergen_may_have_been_dirty(jbyte cv) {
duke@435:     return cv == CardTableRS::cur_youngergen_and_prev_nonclean_card;
duke@435:   }
duke@435: 
duke@435: };