| /* |
| * Copyright (c) 2001, 2012, 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_MEMORY_CARDTABLERS_HPP |
| #define SHARE_VM_MEMORY_CARDTABLERS_HPP |
| |
| #include "memory/cardTableModRefBS.hpp" |
| #include "memory/genRemSet.hpp" |
| #include "memory/memRegion.hpp" |
| |
| class Space; |
| class OopsInGenClosure; |
| |
| // This kind of "GenRemSet" uses a card table both as shared data structure |
| // for a mod ref barrier set and for the rem set information. |
| |
| class CardTableRS: public GenRemSet { |
| friend class VMStructs; |
| // Below are private classes used in impl. |
| friend class VerifyCTSpaceClosure; |
| friend class ClearNoncleanCardWrapper; |
| |
| static jbyte clean_card_val() { |
| return CardTableModRefBS::clean_card; |
| } |
| |
| static intptr_t clean_card_row() { |
| return CardTableModRefBS::clean_card_row; |
| } |
| |
| static bool |
| card_is_dirty_wrt_gen_iter(jbyte cv) { |
| return CardTableModRefBS::card_is_dirty_wrt_gen_iter(cv); |
| } |
| |
| CardTableModRefBSForCTRS* _ct_bs; |
| |
| virtual void younger_refs_in_space_iterate(Space* sp, OopsInGenClosure* cl); |
| |
| void verify_space(Space* s, HeapWord* gen_start); |
| |
| enum ExtendedCardValue { |
| youngergen_card = CardTableModRefBS::CT_MR_BS_last_reserved + 1, |
| // These are for parallel collection. |
| // There are three P (parallel) youngergen card values. In general, this |
| // needs to be more than the number of generations (including the perm |
| // gen) that might have younger_refs_do invoked on them separately. So |
| // if we add more gens, we have to add more values. |
| youngergenP1_card = CardTableModRefBS::CT_MR_BS_last_reserved + 2, |
| youngergenP2_card = CardTableModRefBS::CT_MR_BS_last_reserved + 3, |
| youngergenP3_card = CardTableModRefBS::CT_MR_BS_last_reserved + 4, |
| cur_youngergen_and_prev_nonclean_card = |
| CardTableModRefBS::CT_MR_BS_last_reserved + 5 |
| }; |
| |
| // An array that contains, for each generation, the card table value last |
| // used as the current value for a younger_refs_do iteration of that |
| // portion of the table. (The perm gen is index 0; other gens are at |
| // their level plus 1. They youngest gen is in the table, but will |
| // always have the value "clean_card".) |
| jbyte* _last_cur_val_in_gen; |
| |
| jbyte _cur_youngergen_card_val; |
| |
| int _regions_to_iterate; |
| |
| jbyte cur_youngergen_card_val() { |
| return _cur_youngergen_card_val; |
| } |
| void set_cur_youngergen_card_val(jbyte v) { |
| _cur_youngergen_card_val = v; |
| } |
| bool is_prev_youngergen_card_val(jbyte v) { |
| return |
| youngergen_card <= v && |
| v < cur_youngergen_and_prev_nonclean_card && |
| v != _cur_youngergen_card_val; |
| } |
| // Return a youngergen_card_value that is not currently in use. |
| jbyte find_unused_youngergenP_card_value(); |
| |
| public: |
| CardTableRS(MemRegion whole_heap, int max_covered_regions); |
| |
| // *** GenRemSet functions. |
| GenRemSet::Name rs_kind() { return GenRemSet::CardTable; } |
| |
| CardTableRS* as_CardTableRS() { return this; } |
| |
| CardTableModRefBS* ct_bs() { return _ct_bs; } |
| |
| // Override. |
| void prepare_for_younger_refs_iterate(bool parallel); |
| |
| // Card table entries are cleared before application; "blk" is |
| // responsible for dirtying if the oop is still older-to-younger after |
| // closure application. |
| void younger_refs_iterate(Generation* g, OopsInGenClosure* blk); |
| |
| void inline_write_ref_field_gc(void* field, oop new_val) { |
| jbyte* byte = _ct_bs->byte_for(field); |
| *byte = youngergen_card; |
| } |
| void write_ref_field_gc_work(void* field, oop new_val) { |
| inline_write_ref_field_gc(field, new_val); |
| } |
| |
| // Override. Might want to devirtualize this in the same fashion as |
| // above. Ensures that the value of the card for field says that it's |
| // a younger card in the current collection. |
| virtual void write_ref_field_gc_par(void* field, oop new_val); |
| |
| void resize_covered_region(MemRegion new_region); |
| |
| bool is_aligned(HeapWord* addr) { |
| return _ct_bs->is_card_aligned(addr); |
| } |
| |
| void verify(); |
| void verify_aligned_region_empty(MemRegion mr); |
| |
| void clear(MemRegion mr) { _ct_bs->clear(mr); } |
| void clear_into_younger(Generation* gen); |
| |
| void invalidate(MemRegion mr, bool whole_heap = false) { |
| _ct_bs->invalidate(mr, whole_heap); |
| } |
| void invalidate_or_clear(Generation* gen, bool younger); |
| |
| static uintx ct_max_alignment_constraint() { |
| return CardTableModRefBS::ct_max_alignment_constraint(); |
| } |
| |
| jbyte* byte_for(void* p) { return _ct_bs->byte_for(p); } |
| jbyte* byte_after(void* p) { return _ct_bs->byte_after(p); } |
| HeapWord* addr_for(jbyte* p) { return _ct_bs->addr_for(p); } |
| |
| bool is_prev_nonclean_card_val(jbyte v) { |
| return |
| youngergen_card <= v && |
| v <= cur_youngergen_and_prev_nonclean_card && |
| v != _cur_youngergen_card_val; |
| } |
| |
| static bool youngergen_may_have_been_dirty(jbyte cv) { |
| return cv == CardTableRS::cur_youngergen_and_prev_nonclean_card; |
| } |
| |
| }; |
| |
| class ClearNoncleanCardWrapper: public MemRegionClosure { |
| DirtyCardToOopClosure* _dirty_card_closure; |
| CardTableRS* _ct; |
| bool _is_par; |
| private: |
| // Clears the given card, return true if the corresponding card should be |
| // processed. |
| inline bool clear_card(jbyte* entry); |
| // Work methods called by the clear_card() |
| inline bool clear_card_serial(jbyte* entry); |
| inline bool clear_card_parallel(jbyte* entry); |
| // check alignment of pointer |
| bool is_word_aligned(jbyte* entry); |
| |
| public: |
| ClearNoncleanCardWrapper(DirtyCardToOopClosure* dirty_card_closure, CardTableRS* ct); |
| void do_MemRegion(MemRegion mr); |
| }; |
| |
| #endif // SHARE_VM_MEMORY_CARDTABLERS_HPP |