Mercurial > hg > truffle
view src/share/vm/memory/cardTableRS.hpp @ 15583:d331b7c3d7c4
[single-pass-iter] start of evolution towards a node iterator less memory-hungry
author | Miguel Garcia <miguel.m.garcia@oracle.com> |
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date | Fri, 09 May 2014 16:22:54 +0200 |
parents | 4ca6dc0799b6 |
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/* * Copyright (c) 2001, 2013, 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); ~CardTableRS(); // *** 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* old_gen); void invalidate(MemRegion mr, bool whole_heap = false) { _ct_bs->invalidate(mr, whole_heap); } void invalidate_or_clear(Generation* old_gen); 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